接上文HttpURLConnection

https://blog.csdn.net/nishigesb123/article/details/89328097

上文提到了，Android主要有三种形式实现网络编程，HttpURLConnection一种，Apache HTTP Client也是一种。

但是Android 6.0(api 23) 谷歌将Http Client相关类移除了，并且在官网API文档中也声明，不推荐使用HttpClient而推荐使用HttpURLConnection。

当然，也只是就安卓而言，其他领域或许还是会用到Apache HTTP Client的。

关于被弃用的原因，找到一篇翻译了当时官方声明的博文

https://blog.csdn.net/Jack_EUSong/article/details/50966020

谷歌支持HttpURLConnection原因有：

谷歌不愿意维护HTTPclient ，因为HTTPclient兼容性问题，而支持HttpURLConnection

HttpURLConnection API简便而且包小，对安卓很合适

HttpURLConnection 对于提高速度和节省电池有帮助，同时谷歌也愿意在这方面花时间研究去更进一步的提高性能。

所以本文不对Apache HTTP Client做深究。

另外，为了完成本案例，提供一个测试办法

出处：https://blog.csdn.net/u011150924/article/details/52763443

关于Android 5.1版本后HttpClinet废止，继续使用HttpClinet的方法：

在app下build.gradle中的android闭包内添加：

useLibrary 'org.apache.http.legacy'

Apache HTTP Client

概述

HttpClient是Apache Jakarta Common下的子项目，用来提供高效的、最新的、功能丰富的支持HTTP协议的客户端编程工具包。

HttpClient的项目非常活跃，已经应用在很多的项目中，包括~~在Android中已经集成了HttpClient。~~

下载地址：http://hc.apache.org/downloads.cgi

GET请求

GET方法的操作代码示例如下:

//http地址
String httpUrl="http://10.0.2.2:8080/contact/android?par=HttpClient_android_Get";

//HttpGet连接对象
HttpGet httpRequest = new HttpGet(httpUrl);

//取得HttpClient对象
HttpClient httpclient = new DefaultHttpClient();

//请求HttpClient,取得HttpResponse
HttpResponse httpResponse = httpclient.execute(httpRequest);

//请求成功
if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SCOK) 

//取得返回的字符串
String strResult = EntityUtils.toString(httpResponse.getEntity());

案例

首先配置权限

<uses-permission android:name="android.permission.INTERNET"/>

布局的话就一个按钮，按钮的点击事件为Test

package com.example.a4_16httpclient;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.w3c.dom.Entity;

import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void Test(View view){
        getRequest();
    }
    //使用Apache HTTP Client 的 GET请求
    private void getRequest(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                //换成自己的...
                String path = "http://10.0.2.2:8080/contact/android?username=admin&password=admin";
                //创建请求对象
                HttpGet get = new HttpGet(path);
                //创建HTTP客户端对象，用于发送请求
                HttpClient httpClient = new DefaultHttpClient();
                try {
                    //向服务器发送请求，并返回响应对象
                    HttpResponse response = httpClient.execute(get);
                    //获取响应的状态码
                    int status = response.getStatusLine().getStatusCode();
                    System.out.println("状态码为:"+status);
                    switch (status){
                        case HttpStatus.SC_OK:
                            //200
                            HttpEntity entity = response.getEntity();
                            String result = EntityUtils.toString(entity,"utf-8");
                            System.out.println(result);
                            break;
                        case HttpStatus.SC_NOT_FOUND:
                            //404
                            break;
                        case HttpStatus.SC_INTERNAL_SERVER_ERROR:
                            //500
                            break;
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

测试效果：

服务器端：

客户端：

POST请求

使用POST方法进行参数传递时，需要额外进行一些设置，需要使用NameValuePair来保存要传递的参数，还需要设置所使用的字符集。

// http地址
String httpUrl = "String path = "http://10.0.2.2:8080/contact/android";

//HttpPost连接对象
HttpPost httpRequest =new HttpPost(httpUrl);

//使用NameValuePair来保存要传递的Post参数
List <NameValuePair> params = new ArrayList <NameValuePair>();

//添加要传递的参数
params.add(new BasicNameValuePair("par", "HttpClient_android-Post"));

//设置字符集
HttpEntity httpEntity = new UrlEncodedFormEntity(params,"gb2312");

//请求http
httpRequest.setEntity(httpEntity); 

//取得默认的HttpClient
RequestHttpClient httpclient = new DefaultHttpClient();

//取得HttpResponse
HttpResponse httpResponse = httpclient.execute(httpRequest);

//HttpStatus.SC_OK表示连接成功
if (httpResponse.getStatusLinel).getStatusCode() == HttpStatus.SC_OK) { 
    //取得返回的字符串
    String strResult = EntityUtils.toString(httpResponse.getEntityl);
}

案例

直接接在之前的代码上进行了，增加一个额外的Button（👇代码中点击事件为Test_POST）

package com.example.a4_16httpclient;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.w3c.dom.Entity;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    //使用Apache HTTP Client 的 GET请求
    public void Test(View view) {
        getRequest();
    }

    //使用Apache HTTP Client 的 POST请求
    public void Test_POST(View view) {
        postRequest();
    }

    //使用Apache HTTP Client 的 POST请求 代码基本类似
    private void postRequest() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                //换成自己的...
                String path = "http://10.0.2.2:8080/contact/android";
                //创建请求对象
                HttpPost post = new HttpPost(path);
                ArrayList<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("username", "admin"));
                params.add(new BasicNameValuePair("password", "admin"));

                try {
                    HttpEntity entity = new UrlEncodedFormEntity(params);
                    post.setEntity(entity);
                    HttpClient httpClient = new DefaultHttpClient();
                    HttpResponse response = httpClient.execute(post);
                    switch (response.getStatusLine().getStatusCode()) {
                        case HttpStatus.SC_OK:
                            String result = EntityUtils.toString(response.getEntity());
                            System.out.println(result);
                            break;
                        case HttpStatus.SC_NOT_FOUND:
                            Log.i("HttpClient", "404");
                            break;
                        case HttpStatus.SC_INTERNAL_SERVER_ERROR:
                            Log.i("HttpClient", "500");
                            break;
                    }

                }
                //捕获IO异常就够了
                catch (IOException e) {
                    e.printStackTrace();
                }

            }
        }).start();
    }

    //使用Apache HTTP Client 的 GET请求
    private void getRequest() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                //换成自己的...
                String path = "http://10.0.2.2:8080/contact/android?username=admin&password=admin";
                //创建请求对象
                HttpGet get = new HttpGet(path);
                //创建HTTP客户端对象，用于发送请求
                HttpClient httpClient = new DefaultHttpClient();
                try {
                    //向服务器发送请求，并返回响应对象
                    HttpResponse response = httpClient.execute(get);
                    //获取响应的状态码
                    int status = response.getStatusLine().getStatusCode();
                    System.out.println("状态码为:" + status);
                    switch (status) {
                        case HttpStatus.SC_OK:
                            //200
                            HttpEntity entity = response.getEntity();
                            String result = EntityUtils.toString(entity, "utf-8");
                            System.out.println(result);
                            break;
                        case HttpStatus.SC_NOT_FOUND:
                            //404
                            break;
                        case HttpStatus.SC_INTERNAL_SERVER_ERROR:
                            //500
                            break;
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

效果的话是基本相同的，

客户端

服务器端

安卓网络编程——Apache HTTP Client

Apache HTTP Client

概述

GET请求

案例

POST请求

案例