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Spring Cloud概念+案例(断路器)【下】 https://blog.csdn.net/LawssssCat/article/details/104632719
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【⭐️⭐️⭐️】 Spring Cloud入门-汇总篇(Hoxton版本)
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https://blog.csdn.net/weixin_38305440/article/details/102775484
文章目录
- # spring cloud 是什么?
- # Spring Cloud 不是什么?
- # spring cloud 技术组成
- # Spring Cloud 对比 Dubbo
- 一、service - 服务
- 二、commons 通用项目
- 三、item service 商品服务
- 四、user service 用户服务
- 五、order service 订单服务
- 六、service 访问测试汇总
- 七、注册与发现 - eureka - “尤里卡”(我发现了!)
- # 八、service provider 服务提供者
- 九、eureka 和 “服务提供者”的高可用(高可用,也就是搭建集群了)
- 十、ribbon前提:RestTempplate 服务消费者
- 十一、ribbon 负载均衡(丝滑的纽带)
- # ribbon 重试
# spring cloud 是什么?
spring cloud
是<mark>一系列框架的集合</mark>。它利用 spring boot
的开发便利性巧妙地简化了分布式系统基础设施的开发
微服务中的问题
- 负载均衡
- 重试
- 容错,断路器
- aip 网关
- 配置中心,集中管理和维护配置文件
- 监控
.
<mark>Spring Cloud 是微服务全家桶</mark>
<mark>如服务发现注册、配置中心、消息总线、负载均衡、断路器、数据监控等,都可以用 spring boot
的开发风格做到一键启动和部署</mark>。
spring cloud
并没有重复制造轮子,它只是将目前各家公司开发的比较成熟、经得起实际考验的服务框架组合起来,通过 spring boot
风格进行再封装屏蔽掉了复杂的配置和实现原理,最终给开发者留出了一套<mark>简单易懂、易部署和易维护的分布式系统开发工具包</mark>。
spring cloud
对于中小型互联网公司来说是一种福音,因为这类公司往往没有实力或者没有足够的资金投入去开发自己的分布式系统基础设施,使用 spring cloud
一站式解决方案能在从容应对业务发展的同时大大减少开发成本。
同时,随着近几年微服务架构和 docker
容器概念的火爆,也会让 spring cloud
在未来越来越“云”化的软件开发风格中立有一席之地,尤其是在目前五花八门的分布式解决方案中提供了标准化的、一站式的技术方案,意义可能会堪比当年 servlet 规范的诞生,有效推进服务端软件系统技术水平的进步。
- 使用SpringCloud需要sts - sts安装
# Spring Cloud 不是什么?
不是一个单独的框架,不是解决单一问题的工具。
# spring cloud 技术组成
Spring Cloud - 各组件(eureka、hystrix、ribbon、feign、stream、sleuth)简介
-
eureka
微服务治理,服务注册和发现 -
ribbon
负载均衡、请求重试 -
hystrix
断路器,服务降级、熔断 -
feign
ribbon + hystrix 集成,并提供声明式客户端 -
hystrix dashboard 和 turbine
hystrix 数据监控 -
zuul
API 网关,提供微服务的统一入口,并提供统一的权限验证 -
config
配置中心 -
bus
消息总线, 配置刷新 -
sleuth+zipkin
链路跟踪
# Spring Cloud 对比 Dubbo
-
Dubbo
- Dubbo只是一个远程调用(
RPC
)框架 - 默认基于长连接,支持多种序列化格式
- Dubbo只是一个远程调用(
-
Spring Cloud
- 框架集
- 提供了一整套微服务解决方案(全家桶)
- 基于
http
调用,Rest API
<mark>是
RPC
协议好?还是 基于http
调用Rest API
协议好?</mark>
.+ http 效率比较低(要进行字符串解析)、相比起来,RPC效率高
- 但是,Dubbo 只提供了
远程调用
的问题,而SpringCloud解决了很多问题,因此 市场还是 SpringCloud 多
一、service - 服务
- 商品服务
item service
,端口 8001 - 用户服务
user service
,端口 8101 - 订单服务
order service
,端口 8201
二、commons 通用项目
新建 maven 项目
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>cn.tedu</groupId>
<artifactId>sp01-commons</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>sp01-commons</name>
<dependencies>
<dependency>
<groupId>com.fasterxml.jackson.module</groupId>
<artifactId>jackson-module-parameter-names</artifactId>
<version>2.9.8</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-jdk8</artifactId>
<version>2.9.8</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-jsr310</artifactId>
<version>2.9.8</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-guava</artifactId>
<version>2.9.8</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.6</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.26</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.9</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
## java 源文件
<mark>下面吧全部代码贴上来</mark>
## pojo
Item
package cn.tedu.sp01.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Item {
private Integer id;
private String name;
/**商品库存 or 选择数量*/
private Integer number;
}
User
package cn.tedu.sp01.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
private Integer id;
private String username;
private String password;
}
Order
package cn.tedu.sp01.pojo;
import java.util.List;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Order {
/**如:UUI,按一定规则生成*/
private String id;
/**谁的订单*/
private User user;
/**购买了什么商品*/
private List<Item> items;
}
## service - 先看这里,了解核心业务
商品的业务接口
ItemService
package cn.tedu.sp01.service;
import java.util.List;
import cn.tedu.sp01.pojo.Item;
public interface ItemService {
/**根据订单id,获取订单中的商品列表*/
List<Item> getItems(String orderId);
/**减少商品的库存*/
void decreaseNumbers(List<Item> list);
}
UserService
package cn.tedu.sp01.service;
import cn.tedu.sp01.pojo.User;
public interface UserService {
/** 根据用户id获取用户数据 */
User getUser(Integer id);
/** 增加用户积分 */
void addScore(Integer id, Integer score);
}
OrderService
package cn.tedu.sp01.service;
import cn.tedu.sp01.pojo.Order;
public interface OrderService {
/** 根据订单id获取订单 */
Order getOrder(String orderId);
/** 保存订单的操作 */
void addOrder(Order order);
}
## util
CookieUtil
package cn.tedu.web.util;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class CookieUtil {
/** * @param response * @param name * @param value * @param maxAge */
public static void setCookie(HttpServletResponse response,
String name, String value, String domain, String path, int maxAge) {
Cookie cookie = new Cookie(name, value);
if(domain != null) {
cookie.setDomain(domain);
}
cookie.setPath(path);
cookie.setMaxAge(maxAge);
response.addCookie(cookie);
}
public static void setCookie(HttpServletResponse response, String name, String value, int maxAge) {
setCookie(response, name, value, null, "/", maxAge);
}
public static void setCookie(HttpServletResponse response, String name, String value) {
setCookie(response, name, value, null, "/", 3600);
}
public static void setCookie(HttpServletResponse response, String name) {
setCookie(response, name, "", null, "/", 3600);
}
/** * @param request * @param name * @return */
public static String getCookie(HttpServletRequest request, String name) {
String value = null;
Cookie[] cookies = request.getCookies();
if (null != cookies) {
for (Cookie cookie : cookies) {
if (cookie.getName().equals(name)) {
value = cookie.getValue();
}
}
}
return value;
}
/** * @param response * @param name * @return */
public static void removeCookie(HttpServletResponse response, String name, String domain, String path) {
setCookie(response, name, "", domain, path, 0);
}
}
JsonUtil
package cn.tedu.web.util;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Writer;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.lang3.StringUtils;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.fasterxml.jackson.datatype.guava.GuavaModule;
import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.module.paramnames.ParameterNamesModule;
import lombok.extern.slf4j.Slf4j;
@Slf4j
public class JsonUtil {
private static ObjectMapper mapper;
private static JsonInclude.Include DEFAULT_PROPERTY_INCLUSION = JsonInclude.Include.NON_DEFAULT;
private static boolean IS_ENABLE_INDENT_OUTPUT = false;
private static String CSV_DEFAULT_COLUMN_SEPARATOR = ",";
static {
try {
initMapper();
configPropertyInclusion();
configIndentOutput();
configCommon();
} catch (Exception e) {
log.error("jackson config error", e);
}
}
private static void initMapper() {
mapper = new ObjectMapper();
}
private static void configCommon() {
config(mapper);
}
private static void configPropertyInclusion() {
mapper.setSerializationInclusion(DEFAULT_PROPERTY_INCLUSION);
}
private static void configIndentOutput() {
mapper.configure(SerializationFeature.INDENT_OUTPUT, IS_ENABLE_INDENT_OUTPUT);
}
private static void config(ObjectMapper objectMapper) {
objectMapper.enable(JsonGenerator.Feature.WRITE_BIGDECIMAL_AS_PLAIN);
objectMapper.enable(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT);
objectMapper.enable(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY);
objectMapper.enable(DeserializationFeature.FAIL_ON_READING_DUP_TREE_KEY);
objectMapper.enable(DeserializationFeature.FAIL_ON_NUMBERS_FOR_ENUMS);
objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
objectMapper.disable(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES);
objectMapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
objectMapper.enable(JsonParser.Feature.ALLOW_COMMENTS);
objectMapper.disable(JsonGenerator.Feature.ESCAPE_NON_ASCII);
objectMapper.enable(JsonGenerator.Feature.IGNORE_UNKNOWN);
objectMapper.enable(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES);
objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
objectMapper.enable(JsonParser.Feature.ALLOW_SINGLE_QUOTES);
objectMapper.registerModule(new ParameterNamesModule());
objectMapper.registerModule(new Jdk8Module());
objectMapper.registerModule(new JavaTimeModule());
objectMapper.registerModule(new GuavaModule());
}
public static void setSerializationInclusion(JsonInclude.Include inclusion) {
DEFAULT_PROPERTY_INCLUSION = inclusion;
configPropertyInclusion();
}
public static void setIndentOutput(boolean isEnable) {
IS_ENABLE_INDENT_OUTPUT = isEnable;
configIndentOutput();
}
public static <V> V from(URL url, Class<V> c) {
try {
return mapper.readValue(url, c);
} catch (IOException e) {
log.error("jackson from error, url: {}, type: {}", url.getPath(), c, e);
return null;
}
}
public static <V> V from(InputStream inputStream, Class<V> c) {
try {
return mapper.readValue(inputStream, c);
} catch (IOException e) {
log.error("jackson from error, type: {}", c, e);
return null;
}
}
public static <V> V from(File file, Class<V> c) {
try {
return mapper.readValue(file, c);
} catch (IOException e) {
log.error("jackson from error, file path: {}, type: {}", file.getPath(), c, e);
return null;
}
}
public static <V> V from(Object jsonObj, Class<V> c) {
try {
return mapper.readValue(jsonObj.toString(), c);
} catch (IOException e) {
log.error("jackson from error, json: {}, type: {}", jsonObj.toString(), c, e);
return null;
}
}
public static <V> V from(String json, Class<V> c) {
try {
return mapper.readValue(json, c);
} catch (IOException e) {
log.error("jackson from error, json: {}, type: {}", json, c, e);
return null;
}
}
public static <V> V from(URL url, TypeReference<V> type) {
try {
return mapper.readValue(url, type);
} catch (IOException e) {
log.error("jackson from error, url: {}, type: {}", url.getPath(), type, e);
return null;
}
}
public static <V> V from(InputStream inputStream, TypeReference<V> type) {
try {
return mapper.readValue(inputStream, type);
} catch (IOException e) {
log.error("jackson from error, type: {}", type, e);
return null;
}
}
public static <V> V from(File file, TypeReference<V> type) {
try {
return mapper.readValue(file, type);
} catch (IOException e) {
log.error("jackson from error, file path: {}, type: {}", file.getPath(), type, e);
return null;
}
}
public static <V> V from(Object jsonObj, TypeReference<V> type) {
try {
return mapper.readValue(jsonObj.toString(), type);
} catch (IOException e) {
log.error("jackson from error, json: {}, type: {}", jsonObj.toString(), type, e);
return null;
}
}
public static <V> V from(String json, TypeReference<V> type) {
try {
return mapper.readValue(json, type);
} catch (IOException e) {
log.error("jackson from error, json: {}, type: {}", json, type, e);
return null;
}
}
public static <V> String to(List<V> list) {
try {
return mapper.writeValueAsString(list);
} catch (JsonProcessingException e) {
log.error("jackson to error, obj: {}", list, e);
return null;
}
}
public static <V> String to(V v) {
try {
return mapper.writeValueAsString(v);
} catch (JsonProcessingException e) {
log.error("jackson to error, obj: {}", v, e);
return null;
}
}
public static <V> void toFile(String path, List<V> list) {
try (Writer writer = new FileWriter(new File(path), true)) {
mapper.writer().writeValues(writer).writeAll(list);
writer.flush();
} catch (Exception e) {
log.error("jackson to file error, path: {}, list: {}", path, list, e);
}
}
public static <V> void toFile(String path, V v) {
try (Writer writer = new FileWriter(new File(path), true)) {
mapper.writer().writeValues(writer).write(v);
writer.flush();
} catch (Exception e) {
log.error("jackson to file error, path: {}, obj: {}", path, v, e);
}
}
public static String getString(String json, String key) {
if (StringUtils.isEmpty(json)) {
return null;
}
try {
JsonNode node = mapper.readTree(json);
if (null != node) {
return node.get(key).toString();
} else {
return null;
}
} catch (IOException e) {
log.error("jackson get string error, json: {}, key: {}", json, key, e);
return null;
}
}
public static Integer getInt(String json, String key) {
if (StringUtils.isEmpty(json)) {
return null;
}
try {
JsonNode node = mapper.readTree(json);
if (null != node) {
return node.get(key).intValue();
} else {
return null;
}
} catch (IOException e) {
log.error("jackson get int error, json: {}, key: {}", json, key, e);
return null;
}
}
public static Long getLong(String json, String key) {
if (StringUtils.isEmpty(json)) {
return null;
}
try {
JsonNode node = mapper.readTree(json);
if (null != node) {
return node.get(key).longValue();
} else {
return null;
}
} catch (IOException e) {
log.error("jackson get long error, json: {}, key: {}", json, key, e);
return null;
}
}
public static Double getDouble(String json, String key) {
if (StringUtils.isEmpty(json)) {
return null;
}
try {
JsonNode node = mapper.readTree(json);
if (null != node) {
return node.get(key).doubleValue();
} else {
return null;
}
} catch (IOException e) {
log.error("jackson get double error, json: {}, key: {}", json, key, e);
return null;
}
}
public static BigInteger getBigInteger(String json, String key) {
if (StringUtils.isEmpty(json)) {
return new BigInteger(String.valueOf(0.00));
}
try {
JsonNode node = mapper.readTree(json);
if (null != node) {
return node.get(key).bigIntegerValue();
} else {
return null;
}
} catch (IOException e) {
log.error("jackson get biginteger error, json: {}, key: {}", json, key, e);
return null;
}
}
public static BigDecimal getBigDecimal(String json, String key) {
if (StringUtils.isEmpty(json)) {
return null;
}
try {
JsonNode node = mapper.readTree(json);
if (null != node) {
return node.get(key).decimalValue();
} else {
return null;
}
} catch (IOException e) {
log.error("jackson get bigdecimal error, json: {}, key: {}", json, key, e);
return null;
}
}
public static boolean getBoolean(String json, String key) {
if (StringUtils.isEmpty(json)) {
return false;
}
try {
JsonNode node = mapper.readTree(json);
if (null != node) {
return node.get(key).booleanValue();
} else {
return false;
}
} catch (IOException e) {
log.error("jackson get boolean error, json: {}, key: {}", json, key, e);
return false;
}
}
public static byte[] getByte(String json, String key) {
if (StringUtils.isEmpty(json)) {
return null;
}
try {
JsonNode node = mapper.readTree(json);
if (null != node) {
return node.get(key).binaryValue();
} else {
return null;
}
} catch (IOException e) {
log.error("jackson get byte error, json: {}, key: {}", json, key, e);
return null;
}
}
public static <T> ArrayList<T> getList(String json, String key) {
if (StringUtils.isEmpty(json)) {
return null;
}
String string = getString(json, key);
return from(string, new TypeReference<ArrayList<T>>() {});
}
public static <T> String add(String json, String key, T value) {
try {
JsonNode node = mapper.readTree(json);
add(node, key, value);
return node.toString();
} catch (IOException e) {
log.error("jackson add error, json: {}, key: {}, value: {}", json, key, value, e);
return json;
}
}
private static <T> void add(JsonNode jsonNode, String key, T value) {
if (value instanceof String) {
((ObjectNode) jsonNode).put(key, (String) value);
} else if (value instanceof Short) {
((ObjectNode) jsonNode).put(key, (Short) value);
} else if (value instanceof Integer) {
((ObjectNode) jsonNode).put(key, (Integer) value);
} else if (value instanceof Long) {
((ObjectNode) jsonNode).put(key, (Long) value);
} else if (value instanceof Float) {
((ObjectNode) jsonNode).put(key, (Float) value);
} else if (value instanceof Double) {
((ObjectNode) jsonNode).put(key, (Double) value);
} else if (value instanceof BigDecimal) {
((ObjectNode) jsonNode).put(key, (BigDecimal) value);
} else if (value instanceof BigInteger) {
((ObjectNode) jsonNode).put(key, (BigInteger) value);
} else if (value instanceof Boolean) {
((ObjectNode) jsonNode).put(key, (Boolean) value);
} else if (value instanceof byte[]) {
((ObjectNode) jsonNode).put(key, (byte[]) value);
} else {
((ObjectNode) jsonNode).put(key, to(value));
}
}
public static String remove(String json, String key) {
try {
JsonNode node = mapper.readTree(json);
((ObjectNode) node).remove(key);
return node.toString();
} catch (IOException e) {
log.error("jackson remove error, json: {}, key: {}", json, key, e);
return json;
}
}
public static <T> String update(String json, String key, T value) {
try {
JsonNode node = mapper.readTree(json);
((ObjectNode) node).remove(key);
add(node, key, value);
return node.toString();
} catch (IOException e) {
log.error("jackson update error, json: {}, key: {}, value: {}", json, key, value, e);
return json;
}
}
public static String format(String json) {
try {
JsonNode node = mapper.readTree(json);
return mapper.writerWithDefaultPrettyPrinter().writeValueAsString(node);
} catch (IOException e) {
log.error("jackson format json error, json: {}", json, e);
return json;
}
}
public static boolean isJson(String json) {
try {
mapper.readTree(json);
return true;
} catch (Exception e) {
log.error("jackson check json error, json: {}", json, e);
return false;
}
}
private static InputStream getResourceStream(String name) {
return JsonUtil.class.getClassLoader().getResourceAsStream(name);
}
private static InputStreamReader getResourceReader(InputStream inputStream) {
if (null == inputStream) {
return null;
}
return new InputStreamReader(inputStream, StandardCharsets.UTF_8);
}
}
JsonResult
package cn.tedu.web.util;
import lombok.Getter;
import lombok.Setter;
@Getter
@Setter
public class JsonResult<T> {
/** 成功 */
public static final int SUCCESS = 200;
/** 没有登录 */
public static final int NOT_LOGIN = 400;
/** 发生异常 */
public static final int EXCEPTION = 401;
/** 系统错误 */
public static final int SYS_ERROR = 402;
/** 参数错误 */
public static final int PARAMS_ERROR = 403;
/** 不支持或已经废弃 */
public static final int NOT_SUPPORTED = 410;
/** AuthCode错误 */
public static final int INVALID_AUTHCODE = 444;
/** 太频繁的调用 */
public static final int TOO_FREQUENT = 445;
/** 未知的错误 */
public static final int UNKNOWN_ERROR = 499;
private int code;
private String msg;
private T data;
public static JsonResult build() {
return new JsonResult();
}
public static JsonResult build(int code) {
return new JsonResult().code(code);
}
public static JsonResult build(int code, String msg) {
return new JsonResult<String>().code(code).msg(msg);
}
public static <T> JsonResult<T> build(int code, T data) {
return new JsonResult<T>().code(code).data(data);
}
public static <T> JsonResult<T> build(int code, String msg, T data) {
return new JsonResult<T>().code(code).msg(msg).data(data);
}
public JsonResult<T> code(int code) {
this.code = code;
return this;
}
public JsonResult<T> msg(String msg) {
this.msg = msg;
return this;
}
public JsonResult<T> data(T data) {
this.data = data;
return this;
}
public static JsonResult ok() {
return build(SUCCESS);
}
public static JsonResult ok(String msg) {
return build(SUCCESS, msg);
}
public static <T> JsonResult<T> ok(T data) {
return build(SUCCESS, data);
}
public static JsonResult err() {
return build(EXCEPTION);
}
public static JsonResult err(String msg) {
return build(EXCEPTION, msg);
}
@Override
public String toString() {
return JsonUtil.to(this);
}
}
三、item service 商品服务
- 新建项目
- 配置依赖 pom.xml
- 配置 application.yml
- 配置主程序
- 编写代码
## 新建 spring boot 起步项目
## 选择依赖项
只选择 web
pom.xml
要填加 sp01-commons 项目依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.tedu</groupId>
<artifactId>sp02-itemservice</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>sp02-itemservice</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>cn.tedu</groupId>
<artifactId>sp01-commons</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
## application.yml
spring:
application:
name: item-service
server:
port: 8001
## 主程序
默认代码,不需要修改
package cn.tedu.sp02;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Sp02ItemserviceApplication {
public static void main(String[] args) {
SpringApplication.run(Sp02ItemserviceApplication.class, args);
}
}
## java 源文件
<mark>主要是 controller 和 service</mark>
ItemServiceImpl
package cn.tedu.sp02.item.service;
import java.util.ArrayList;
import java.util.List;
import org.springframework.stereotype.Service;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.service.ItemService;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@Service
public class ItemServiceImpl implements ItemService {
@Override
public List<Item> getItems(String orderId) {
ArrayList<Item> list = new ArrayList<Item>();
list.add(new Item(1, "商品 1",1));
list.add(new Item(2, "商品 2",2));
list.add(new Item(3, "商品 3",3));
list.add(new Item(4, "商品 4",4));
list.add(new Item(5, "商品 5",5));
return list;
}
@Override
public void decreaseNumbers(List<Item> list) {
for(Item item : list) {
log.info("减少库存 - "+item);
}
}
}
ItemController
package cn.tedu.sp02.item.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.service.ItemService;
import cn.tedu.web.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@RestController
public class ItemController {
@Autowired
private ItemService itemService;
@Value("${server.port}")
private int port;
@GetMapping("/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId) {
log.info("server.port="+port+", orderId="+orderId);
List<Item> items = itemService.getItems(orderId);
return JsonResult.ok(items).msg("port="+port);
}
@PostMapping("/decreaseNumber")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {
itemService.decreaseNumbers(items);
return JsonResult.ok();
}
}
## 访问测试
根据orderid
,查询商品
http://localhost:8001/35
减少商品库存
http://localhost:8001/decreaseNumber
使用postman
,POST
发送以下格式数据:
[{"id":1, "name":"abc", "number":23},{"id":2, "name":"def", "number":11}]
源码:
https://github.com/benwang6/spring-cloud-repo
四、user service 用户服务
- 新建项目
- 配置依赖 pom.xml
- 配置 application.yml
- 配置主程序
- 编写代码
## 新建 spring boot 起步项目
## 选择依赖项
只选择 web
pom.xml
要填加 sp01-commons 项目依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.tedu</groupId>
<artifactId>sp03-userservice</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>sp03-userservice</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>cn.tedu</groupId>
<artifactId>sp01-commons</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
## application.yml
其中 sp.user-service.users 属性为自定义属性,提供用于测试的用户数据
sp:
user-service:
users: "[{\"id\":7, \"username\":\"abc\",\"password\":\"123\"},{\"id\":8, \"username\":\"def\",\"password\":\"456\"},{\"id\":9, \"username\":\"ghi\",\"password\":\"789\"}]"
spring:
application:
name: user-service
server:
port: 8101
## 主程序
默认代码,不需要修改
package cn.tedu.sp03;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Sp03UserserviceApplication {
public static void main(String[] args) {
SpringApplication.run(Sp03UserserviceApplication.class, args);
}
}
## java源文件
UserServiceImpl
package cn.tedu.sp03.user.service;
import java.util.List;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import com.fasterxml.jackson.core.type.TypeReference;
import cn.tedu.sp01.pojo.User;
import cn.tedu.sp01.service.UserService;
import cn.tedu.web.util.JsonUtil;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@Service
public class UserServiceImpl implements UserService {
@Value("${sp.user-service.users}")
private String userJson;
@Override
public User getUser(Integer id) {
log.info("users json string : "+userJson);
List<User> list = JsonUtil.from(userJson, new TypeReference<List<User>>() {});
for (User u : list) {
if (u.getId().equals(id)) {
return u;
}
}
return new User(id, "name-"+id, "pwd-"+id);
}
@Override
public void addScore(Integer id, Integer score) {
// 这里增加积分
log.info("user "+id+" - 增加积分 "+score);
}
}
UserController
package cn.tedu.sp03.user.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import cn.tedu.sp01.pojo.User;
import cn.tedu.sp01.service.UserService;
import cn.tedu.web.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@RestController
public class UserController {
@Autowired
private UserService userService;
@GetMapping("/{userId}")
public JsonResult<User> getUser(@PathVariable Integer userId) {
log.info("get user, userId="+userId);
User u = userService.getUser(userId);
return JsonResult.ok(u);
}
@GetMapping("/{userId}/score")
public JsonResult addScore(
@PathVariable Integer userId, Integer score) {
userService.addScore(userId, score);
return JsonResult.ok();
}
}
## 访问测试
根据userid查询用户信息
http://localhost:8101/7
根据userid,为用户增加积分
http://localhost:8101/7/score?score=100
五、order service 订单服务
- 新建项目
- 配置依赖 pom.xml
- 配置 application.yml
- 配置主程序
- 编写代码
## 新建 spring boot 起步项目
## 选择依赖项
只选择 web
pom.xml
<mark>要填加 sp01-commons 项目依赖</mark>
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.tedu</groupId>
<artifactId>sp04-orderservice</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>sp04-orderservice</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>cn.tedu</groupId>
<artifactId>sp01-commons</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
## applicatoin.yml
spring:
application:
name: order-service
server:
port: 8201
## 主程序
默认代码,不需要修改
package cn.tedu.sp04;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Sp04OrderserviceApplication {
public static void main(String[] args) {
SpringApplication.run(Sp04OrderserviceApplication.class, args);
}
}
## java 源文件
OrderServiceImpl
package cn.tedu.sp04.order.service;
import org.springframework.stereotype.Service;
import cn.tedu.sp01.pojo.Order;
import cn.tedu.sp01.service.OrderService;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@Service
public class OrderServiceImpl implements OrderService {
@Override
public Order getOrder(String orderId) {
//TODO: 调用user-service获取用户信息
//TODO: 调用item-service获取商品信息
Order order = new Order();
order.setId(orderId);
return order;
}
@Override
public void addOrder(Order order) {
//TODO: 调用item-service减少商品库存
//TODO: 调用user-service增加用户积分
log.info("保存订单:"+order);
}
}
OrderController
package cn.tedu.sp04.order.controller;
import java.util.Arrays;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.pojo.Order;
import cn.tedu.sp01.pojo.User;
import cn.tedu.sp01.service.OrderService;
import cn.tedu.web.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@RestController
public class OrderController {
@Autowired
private OrderService orderService;
@GetMapping("/{orderId}")
public JsonResult<Order> getOrder(@PathVariable String orderId) {
log.info("get order, id="+orderId);
Order order = orderService.getOrder(orderId);
return JsonResult.ok(order);
}
@GetMapping("/")
public JsonResult addOrder() {
//模拟post提交的数据
Order order = new Order();
order.setId("123abc");
order.setUser(new User(7,null,null));
order.setItems(Arrays.asList(new Item[] {
new Item(1,"aaa",2),
new Item(2,"bbb",1),
new Item(3,"ccc",3),
new Item(4,"ddd",1),
new Item(5,"eee",5),
}));
orderService.addOrder(order);
return JsonResult.ok();
}
}
## 访问测试
根据orderid,获取订单
http://localhost:8201/123abc
保存订单,观察控制台日志输出
http://localhost:8201/
六、service 访问测试汇总
-
item-service
根据orderid,查询商品
http://localhost:8001/35
减少商品库存
http://localhost:8001/decreaseNumber
使用postman,POST发送以下格式数据:
[{"id":1, "name":"abc", "number":23},{"id":2, "name":"def", "number":11}]
-
user-service
根据userid查询用户信息
http://localhost:8101/7
根据userid,为用户增加积分
http://localhost:8101/7/score?score=100
-
order-service
根据orderid,获取订单
http://localhost:8201/123abc
保存订单,观察控制台日志输出
http://localhost:8201/
七、注册与发现 - eureka - “尤里卡”(我发现了!)
注册、发现啥意思?
- 在注册中心注册
- 在地址表发现地址
## eureka 注册中心
注册中心是整个微服务系统的一个核心服务,
- 左右服务启动,都要向
eureka
进行注册 - 服务之间调用,需要从
eureka
请求路径
## eureka 的执行参数
- 注册
- 服务启动时,就会连接 eureka 进行注册
- 如果注册失败,就会一次次反复尝试,<mark>直到成功为止</mark>。
- 拉取
- <mark>每一段时间(30s)更新一次注册地址表</mark>
- 一个新的服务注册后,其他服务不能立即感知新服务的地址,需要最长等待30s,才能得到新的地址表
- 心跳
- 每一段时间(30s)发送一次心跳数据
- 如果连续三次丢失心跳数据,会删除这个服务的注册信息
- <mark>自我保护模式(与zookeeper的主要区别)</mark>
- 15分钟内,85%的服务器出现心跳异常,eureka会认为网络不稳定,会进入自我保护模式。
- 自我保护模式下:
- 会保护所有服务的注册信息,不被删除
- 直到恢复正常后,会自动退出保护模式,恢复正常
## eureka 和 zookeeper 的区别
参考:Spring Cloud Eureka简介及与Zookeeper对比
前提知识: CAP理论/AP架构/CP架构
- P(
partition
) - 分区容错性:由于网络问题,将系统的成员<mark>隔离</mark>成了2个区域,互相无法知道对方的状态
(注意:CAP
理论提出就是针对分布式数据库环境的,所以,<mark>P这个属性是必须具备的。</mark>)- A(
Availability
) - 可用性:通过<mark>节点复制</mark>,失去联系的节点依然可以向系统提供服务,不过它的数据就不能保证是同步的了(失去了C属性)- C(
Consistency
) - 一致性:为了保证数据库的一致性,我们必须<mark>等待</mark>失去联系的节点恢复过来,在这个过程中,那个节点是不允许对外提供服务的,这时候系统处于不可用状态(失去了A属性)
eureka
- AP - 强调可用性,和分区容错性
可用性:当服务不可用,能知道不可用
- 集群 - 对等结构
服务器间,没有主从区分
<mark>优点:服务不中断</mark>
<mark>缺点:不一致</mark>
zookeeper
- CP - 强调一致性,和分区容错性
- 集群 - 主从结构
主服务器对外提供服务,当主服务器不可用,会从从服务器中选取,成为新主服务器
<mark>坏处:主服务器宕机,服务可能中断</mark>
- 创建eureka项目
- 配置依赖 pom.xml
- 配置 application.yml
- 主程序启用 eureka 服务器
- 启动,访问测试
## 创建 eureka server 项目:sp05-eureka
## pom.xml
注意几点:
- parent 版本
- properties用的
Hoxton - dependencyManagement
中指定的版本
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.tedu</groupId>
<artifactId>sp05-eureka</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>sp05-eureka</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Hoxton.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
application.yml
spring:
application:
name: eureka-server
server:
port: 2001
eureka:
server:
enable-self-preservation: false
instance:
hostname: eureka1
client:
register-with-eureka: false
fetch-registry: false
-
eureka
集群服务器之间,通过hostname
来区分 (为以后集群准备) -
eureka.server.enable-self-preservation
(开发期间关闭,生产期间再打开)
eureka
的自我保护状态:
心跳失败的比例,在15分钟内是否低于85%,如果出现了低于的情况,Eureka Server
会将当前的实例注册信息保护起来,同时提示一个警告,
一旦进入保护模式,Eureka Server
将会尝试保护其服务注册表中的信息,不再删除服务注册表中的数据。也就是不会注销任何微服务 -
eureka.client.register-with-eureka=false
不向自身注册 -
eureka.client.fetch-registry=false
不从自身拉取注册信息 -
eureka.instance.lease-expiration-duration-in-seconds
最后一次心跳后,间隔多久认定微服务不可用,默认90
## 主程序
添加 @EnableEurekaServer
package cn.tedu.sp05;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer
@SpringBootApplication
public class Sp05EurekaApplication {
public static void main(String[] args) {
SpringApplication.run(Sp05EurekaApplication.class, args);
}
}
## 修改 hosts 文件,添加 eureka 域名映射
C:\Windows\System32\drivers\etc\hosts
添加内容:
127.0.0.1 eureka1
127.0.0.1 eureka2
## 启动,并访问测试
http://eureka1:2001
# 八、service provider 服务提供者
- 修改 item-service、user-service、order-service,把微服务注册到 eureka 服务器
- pom.xml 添加eureka依赖
- application.yml 添加eureka注册配置
- 主程序启用eureka客户端
- 启动服务,在eureka中查看注册信息
## pom.xml 添加 eureka 客户端依赖
右键点击项目,或点击pom.xml,用 STS 工具编辑起步依赖
上面的操作会在pom.xml中添加以下依赖
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
## application.yml 添加 eureka注册配置
eureka:
client:
service-url:
# 容灾:指定 eureka 的地点
# 单机部署,必须结合公共的云服务器(阿里云/腾讯云/亚马逊云...)
# 我们现在只能这么写,写不了别的
defaultZone: http://eureka1:2001/eureka
-
eureka.instance.lease-renewal-interval-in-seconds
心跳间隔时间,默认 30 秒 -
defaultZone
,默认位置,可以修改为具体地理位置,比如:beiJing, shangHai, shenZhen 等,表示 eureka 服务器的部署位置, 需要云服务器提供 -
eureka.client.registry-fetch-interval-seconds
拉取注册信息间隔时间,默认 30 秒
## 主程序启用服务注册发现客户端
修改 item-service、user-service 和 order-service,
主程序添加 @EnableDiscoveryClient 注解
## 启动,并访问 eureka 查看注册信息
http://eureka1:2001
这个是保护模式,
九、eureka 和 “服务提供者”的高可用(高可用,也就是搭建集群了)
- 《Spring Cloud服务注册中心Eureka》 - http://www.belonk.com/c/spring_cloud_eureka.html
高可用:每个服务都要有备用服务器
.
为了方便,现在只搭建 商品(item)集群和 eureka 集群
## item-service 高可用
启动参数 --server.port 可以覆盖yml中的端口配置
配置启动参数
item-service-8001
在Eureka中,服务名称不区分大小写
java -jar (项目名).jar--server.port=8001
- item-service-8002
--server.port=8002
(了解)发布 jar (结果与上一步一样)
执行 install 命令,并且 跳过 测试(不打包测试)
打包完成
打包完成会在 target 和 本地仓库各放一份
默认启动 8001
java -jar sp02xxxxxxxxxxxxxxxxxxxxx
启动 8002
java -jar sp02xxxxxxxxxxxxxxxxxxxxx --server.port=8002
启动测试
访问 eureka
查看 item-service
注册信息
- 访问两个端口测试
http://localhost:8001/35
http://localhost:8002/35
## eureka 高可用
添加两个服务器的 profile 配置文件
application-eureka1.yml
eureka:
instance:
hostname: eureka1 # 以hostname作为身份
client:
# 保护模式 开发期间关闭(搭建集群时候需要开启)
# 互相注册
register-with-eureka: true # profile的配置会覆盖公用配置
# 互相拉取
fetch-registry: true # profile的配置会覆盖公用配置
service-url:
defaultZone: http://eureka2:2002/eureka # eureka1启动时向eureka2注册
application-eureka2.yml
eureka:
instance:
hostname: eureka2
client:
register-with-eureka: true # profile的配置会覆盖公用配置
fetch-registry: true # profile的配置会覆盖公用配置
service-url:
defaultZone: http://eureka1:2001/eureka # eureka2启动时向eureka1注册
配置启动参数 --spring.profiles.active 和 --server.port
- <mark>eureka1 启动参数:</mark>
--spring.profiles.active=eureka1 --server.port=2001
<mark>
eureka1
指的是文件名后面的字符串 application-eureka2
.yml</mark>
- <mark>eureka2 启动参数:</mark>
--spring.profiles.active=eureka2 --server.port=2002
如果在命令行运行,可以在命令行中添加参数:
java -jar xxx.jar --spring.profiles.active=eureka1 --server.port=2001
访问 eureka 服务器,查看注册信息
这里的 DS Replicas 就是
Discovery Service Replicas
发现服务的服务备份
http://eureka1:2001/
http://eureka2:2002/
replicas 复制品
## eureka客户端注册时,向两个服务器注册
修改以下微服务
- sp02-itemservice
- sp03-userservice
- sp04-orderservice
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
当一个 eureka
服务宕机时,仍可以连接另一个 eureka
服务
十、ribbon前提:RestTempplate 服务消费者
ribbon
提供了负载均衡和重试功能, 它底层是使用 RestTemplate
进行 Rest api
调用
(对RestTemplate做了代码增强,添加了负载均衡和重试的代码)
(实现原理是 Spring AOP)
功能:
- 负载均衡
- 重试
## RestTempplate
Spring Boot
提供的一个远程调用工具
它对 Rest 调用的过程,提供了高度的封装,暴露给我们的调用的方法,非常简单
getForObject("http://localhost:8001/{1}", JsonResult.class, "t2t;jt")
postForObject("http://localhost:8001/decreaseNumber")
我们下面先看 RestTemplate ,然后再结合 ribbon
下面我们先不使用ribbon, 单独使用RestTemplate来执行远程调用
新建 ribbon 项目
pom.xml
application.yml
主程序
controller
启动,并访问测试
新建 sp06-ribbon 项目
pom.xml
- <mark>eureka-client 中已经包含 ribbon 依赖</mark>
- <mark>需要添加 sp01-commons 依赖</mark>
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.tedu</groupId>
<artifactId>sp06-ribbon</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>sp06-ribbon</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Hoxton.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>cn.tedu</groupId>
<artifactId>sp01-commons</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
application.yml
spring:
application:
name: ribbon
server:
port: 3001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
## 主程序
创建 RestTemplate
实例
RestTemplate
是用来调用其他微服务的工具类,封装了远程调用代码,提供了一组用于远程调用的模板方法
例如: getForObject()
、 postForObject()
等
package cn.tedu.sp06;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@EnableDiscoveryClient
@SpringBootApplication
public class Sp06RibbonApplication {
//创建 RestTemplate 实例,并存入 spring 容器
@Bean
public RestTemplate getRestTemplate() {
return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(Sp06RibbonApplication.class, args);
}
}
RibbonController
package cn.tedu.sp06.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.pojo.Order;
import cn.tedu.sp01.pojo.User;
import cn.tedu.web.util.JsonResult;
@RestController
public class RibbonController {
@Autowired
private RestTemplate rt;
@GetMapping("/item-service/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId) {
//向指定微服务地址发送 get 请求,并获得该服务的返回结果
//{1} 占位符,用 orderId 填充
return rt.getForObject("http://localhost:8001/{1}", JsonResult.class, orderId);
}
@PostMapping("/item-service/decreaseNumber")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {
//发送 post 请求
return rt.postForObject("http://localhost:8001/decreaseNumber", items, JsonResult.class);
}
/////////////////////////////////////////
@GetMapping("/user-service/{userId}")
public JsonResult<User> getUser(@PathVariable Integer userId) {
return rt.getForObject("http://localhost:8101/{1}", JsonResult.class, userId);
}
@GetMapping("/user-service/{userId}/score")
public JsonResult addScore(
@PathVariable Integer userId, Integer score) {
return rt.getForObject("http://localhost:8101/{1}/score?score={2}", JsonResult.class, userId, score);
}
/////////////////////////////////////////
@GetMapping("/order-service/{orderId}")
public JsonResult<Order> getOrder(@PathVariable String orderId) {
return rt.getForObject("http://localhost:8201/{1}", JsonResult.class, orderId);
}
@GetMapping("/order-service")
public JsonResult addOrder() {
return rt.getForObject("http://localhost:8201/", JsonResult.class);
}
}
启动服务,并访问测试
-
http://eureka1:2001
-
http://localhost:3001/item-service/35
-
http://localhost:3001/item-service/decreaseNumber
使用postman,POST发送以下格式数据:
[{"id":1, "name":"abc", "number":23},{"id":2, "name":"def", "number":11}]
-
http://localhost:3001/user-service/7
-
http://localhost:3001/user-service/7/score?score=100
-
http://localhost:3001/order-service/123abc
-
http://localhost:3001/order-service/
十一、ribbon 负载均衡(丝滑的纽带)
@LoacBalance
注解,对RestTemplate
进行增强- 请求服务器地址,写
service-id
http://item-service/{1}
修改 sp06-ribbon 项目
## 添加 ribbon 起步依赖(可选)
RestTemplate
设置 @LoadBalanced
访问路径设置为服务 id
添加 ribbon
起步依赖(可选)
eureka
依赖中已经包含了 ribbon
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency>
## RestTemplate 设置 @LoadBalanced
@LoadBalanced
负载均衡注解,会对 RestTemplate
实例进行封装,创建动态***对象,并切入(AOP
)负载均衡代码,把请求分发到集群中的服务器
package cn.tedu.sp06;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@EnableDiscoveryClient
@SpringBootApplication
public class Sp06RibbonApplication {
@LoadBalanced //负载均衡注解
@Bean
public RestTemplate getRestTemplate() {
return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(Sp06RibbonApplication.class, args);
}
}
## 访问路径设置为服务id
<mark>在Eureka中,服务名称不区分大小写</mark>
package cn.tedu.sp06.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.pojo.Order;
import cn.tedu.sp01.pojo.User;
import cn.tedu.web.util.JsonResult;
@RestController
public class RibbonController {
@Autowired
private RestTemplate rt;
@GetMapping("/item-service/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId) {
//这里服务器路径用 service-id 代替,ribbon 会向服务的多台集群服务器分发请求
// 另外在Eureka中,服务名称不区分大小写, 可以写成:http://ITEM-SERVICE/{1}
return rt.getForObject("http://item-service/{1}", JsonResult.class, orderId);
}
@PostMapping("/item-service/decreaseNumber")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {
return rt.postForObject("http://item-service/decreaseNumber", items, JsonResult.class);
}
/////////////////////////////////////////
@GetMapping("/user-service/{userId}")
public JsonResult<User> getUser(@PathVariable Integer userId) {
return rt.getForObject("http://user-service/{1}", JsonResult.class, userId);
}
@GetMapping("/user-service/{userId}/score")
public JsonResult addScore(
@PathVariable Integer userId, Integer score) {
return rt.getForObject("http://user-service/{1}/score?score={2}", JsonResult.class, userId, score);
}
/////////////////////////////////////////
@GetMapping("/order-service/{orderId}")
public JsonResult<Order> getOrder(@PathVariable String orderId) {
return rt.getForObject("http://order-service/{1}", JsonResult.class, orderId);
}
@GetMapping("/order-service")
public JsonResult addOrder() {
return rt.getForObject("http://order-service/", JsonResult.class);
}
}
## 访问测试
访问测试,ribbon
会把请求分发到 8001 和 8002 两个服务端口上
http://localhost:3001/item-service/34
# ribbon 重试
pom.xml
添加 spring-retry
依赖
复制代码到 pom.xml
<dependency>
<groupId>org.springframework.retry</groupId>
<artifactId>spring-retry</artifactId>
</dependency>
这个依赖在 edit spring 中不能直接找到(以前有的)
所以要手动复制(MVN中找)
## application.yml 配置 ribbon 重试
spring:
application:
name: ribbon
server:
port: 3001
eureka:
client:
service-url:
defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
ribbon:
MaxAutoRetriesNextServer: 2
MaxAutoRetries: 1
OkToRetryOnAllOperations: true
ConnectionTimeout
建立连接的超时时间ReadTimeout
接收响应的超时时间
两个超时参数,不能直接在 yml 配置文件中进行配置(ribbon目前版本的问题,以后可能可以)
.
现在,需要在java 代码中 ,使用SimpleClientHttpRequestFactory
工厂对象中进行配置
-
OkToRetryOnAllOperations=true
是否对所有类型请求(GET、POST、…)都进行重试?默认只对get重试 -
MaxAutoRetriesNextServer
最大向后更换几台服务器 -
MaxAutoRetries
初始请求失败后,对单台服务器的重试次数(如:5的话,最多请求6次)
最多请求数:
MaxAutoRetriesNextServer
x (MaxAutoRetries
+ 1) 次
## 主程序设置 RestTemplate 的请求工厂的超时属性
package cn.tedu.sp06;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;
@EnableDiscoveryClient
@SpringBootApplication
public class Sp06RibbonApplication {
@LoadBalanced
@Bean
public RestTemplate getRestTemplate() {
SimpleClientHttpRequestFactory f = new SimpleClientHttpRequestFactory();
f.setConnectTimeout(1000);
f.setReadTimeout(1000);
return new RestTemplate(f);
//RestTemplate 中默认的 Factory 实例中,两个超时属性默认是 -1,
//未启用超时,也不会触发重试
//return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(Sp06RibbonApplication.class, args);
}
}
## item-service 的 ItemController 添加延迟代码
<mark>以便测试 ribbon 的重试机制</mark>
package cn.tedu.sp02.item.controller;
import java.util.List;
import java.util.Random;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.service.ItemService;
import cn.tedu.web.util.JsonResult;
import lombok.extern.slf4j.Slf4j;
@Slf4j
@RestController
public class ItemController {
@Autowired
private ItemService itemService;
@Value("${server.port}")
private int port;
@GetMapping("/{orderId}")
public JsonResult<List<Item>> getItems(@PathVariable String orderId) throws Exception {
log.info("server.port="+port+", orderId="+orderId);
///--设置随机延迟
if(Math.random()<0.6) {
long t = new Random().nextInt(5000);
log.info("item-service-"+port+" - 暂停 "+t);
Thread.sleep(t);
}
///~~
List<Item> items = itemService.getItems(orderId);
return JsonResult.ok(items).msg("port="+port);
}
@PostMapping("/decreaseNumber")
public JsonResult decreaseNumber(@RequestBody List<Item> items) {
itemService.decreaseNumbers(items);
return JsonResult.ok();
}
}
## 访问,测试 ribbon 重试机制
通过 ribbon
访问 item-service
,当超时,ribbon
会重试请求集群中其他服务器
http://localhost:3001/item-service/35
- <mark>ribbon的重试机制,在 feign 和 zuul 中进一步进行了封装,后续可以使用feign或zuul的重试机制</mark>
文章目录
- # spring cloud 是什么?
- # Spring Cloud 不是什么?
- # spring cloud 技术组成
- # Spring Cloud 对比 Dubbo
- 一、service - 服务
- 二、commons 通用项目
- 三、item service 商品服务
- 四、user service 用户服务
- 五、order service 订单服务
- 六、service 访问测试汇总
- 七、注册与发现 - eureka - “尤里卡”(我发现了!)
- # 八、service provider 服务提供者
- 九、eureka 和 “服务提供者”的高可用(高可用,也就是搭建集群了)
- 十、ribbon前提:RestTempplate 服务消费者
- 十一、ribbon 负载均衡(丝滑的纽带)
- # ribbon 重试