如何实现自定义Starter

先创建一个父工程

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推荐学习：谈起SpringBoot，面试官（Java）必问题：讲述一下 SpringBoot 自动装配原理？

我们会把自定义starter放到这个父工程里面,然后建立一个子工程去引入那个自定义starter

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自定义Starter的命名规范

• 官方命名空间

• 前缀：spring-boot-starter-

• 模式：spring-boot-starter-模块名

• 举例：spring-boot-starter-web、spring-boot-starter-jdbc

• 自定义命名空间

• 后缀：-spring-boot-starter

• 模式：模块-spring-boot-starter

• 举例：mybatis-spring-boot-starter

开始创建自定义Starter

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引入依赖

<?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 http://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>2.6.4</version> </parent> <groupId>linc.fun</groupId> <artifactId>linc-spring-boot-starter</artifactId> <version>1.0-SNAPSHOT</version> <properties> <spring-boot.version>2.6.4</spring-boot.version> </properties> <dependencies> <!-- 引入autoconfigure--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-configuration-processor</artifactId> <optional>true</optional> </dependency> <!--SpringBootWeb--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>${spring-boot.version}</version> </dependency> </dependencies> <repositories> <repository> <id>springsource-repos</id> <name>SpringSource Repository</name> <url>http://repo.spring.io/release/</url> </repository> <repository> <id>activiti-repos2</id> <name>Activiti Repository 2</name> <url>https://app.camunda.com/nexus/content/groups/public</url> </repository> <repository> <id>central-repos</id> <name>Central Repository</name> <url>http://repo.maven.apache.org/maven2</url> </repository> </repositories> </project> 

我们自定义一个配置文件

@ConfigurationProperties("linc.properties") public class MyProperties { @Value("${linc.properties.name}") private String name; public String getName() { return name;
    } public void setName(String name) { this.name = name;
    }
}

自定义一个Controller

@RestController public class MyController { @Resource private MyProperties myProperties; @RequestMapping("/my") public String my() {
        System.out.println("my...."); return myProperties.getName() + ",正在测试...";
    }
}

定义一个自动配置类

@Configuration @ConditionalOnProperty(value = "linc.properties.name") @EnableConfigurationProperties(MyProperties.class) public class MyAutoConfiguration {

}

在resources目录下创建META-INF/spring.factories

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
  linc.fun.MyAutoConfiguration

到这儿,我们的配置自定义的starter就写完了

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我们进行打包

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创建另外一个子项目,引入我们这个自定义Starter

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引入依赖

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>linc.fun</groupId> <artifactId>linc-project</artifactId> <version>1.0-SNAPSHOT</version> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>linc.fun</groupId> <artifactId>linc-spring-boot-starter</artifactId> <version>1.0-SNAPSHOT</version> </dependency> </dependencies> </project> 

创建启动类以及配置文件填写

启动类

@SpringBootApplication public class Application { public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

application.yml

server:
  port: 8080

linc:
  properties:
    name: linc

访问 http://localhost:8080/my

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注意我们配置了@ConditionalOnProperty(value = "linc.properties.name")

所以在application.yml配置了这个配置信息才能成功启动