httpclient学习（环境搭建，发送get，post请求）

httpclient是一个客户端接口调用框架，实现了http协议的客户端接口调用技术，可以通过模拟测试工具发起接口请求，完成接口调用。

环境搭建：在pom.xml文件里面添加以下标签

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.2</version>
</dependency>

 理解什么是接口：

接口的本质：

接口测试流程：

httpclient发送get请求：

代码实现：

package com.mg.api.auto;

import java.io.IOException;

import org.apache.http.Header;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

/**
 * httpclient发送get请求
 * 
 * @author admin
 *
 */
public class GetDemo {
    public static void main(String[] args) throws ClientProtocolException, IOException {
        // 准备url
        String url = "https://tcc.taobao.com/cc/json/mobile_tel_segment.htm";

        // 准备测试数据
        String tel = "18581232148";
        url += ("?tel=" + tel); // 拼接url
        System.out.println(url);

        // 请求方式:get
        HttpGet get = new HttpGet(url);

        // 发送请求,获取响应
        HttpClient httpClient = HttpClients.createDefault();
        HttpResponse response = httpClient.execute(get);

        // 获取响应状态码
        int code = response.getStatusLine().getStatusCode();
        System.out.println(code);

        // 获取响应内容
        String result = EntityUtils.toString(response.getEntity());
        System.out.println(result);

        // 获取响应头信息
        Header[] headers = response.getAllHeaders();
        for (Header header : headers) {
            System.out.println(header);
        }
    }
}

get请求运行结果：

httpclient发送post请求：

代码实现：

package com.mg.api.auto;

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

import org.apache.http.Header;
import org.apache.http.HttpResponse;
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.HttpPost;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

/**
 * httpclient发送post请求
 * 
 * @author admin
 *
 */
public class PostDemo {
    public static void main(String[] args) throws ClientProtocolException, IOException {
        // 接口地址
        String loginUrl = "http://49.235.92.12:9000/api/v1/login";

        // 接口请求方式:post
        HttpPost post = new HttpPost(loginUrl);

        // 接口测试数据
        String username = "test";
        String password = "123456";
        List<BasicNameValuePair> parameters = new ArrayList<BasicNameValuePair>();
        parameters.add(new BasicNameValuePair("username", username));
        parameters.add(new BasicNameValuePair("password", password));
        post.setEntity(new UrlEncodedFormEntity(parameters, "utf-8"));

        // 发送请求，获取响应
        HttpClient client = HttpClients.createDefault(); // 创建默认客户端，相当于按钮
        HttpResponse response = client.execute(post);

        // 状态码
        int code = response.getStatusLine().getStatusCode();
        System.out.println("状态码：" + code);

        // 响应报文
        String result = EntityUtils.toString(response.getEntity()); // json转为string
        System.out.println("响应报文：" + result);

        // 获取响应头信息
        Header[] headers = response.getAllHeaders();
        for (Header header : headers) {
            System.out.println("响应头信息：" + header);
        }
    }

}

post请求运行结果：

常用HttpResponse响应方法：

封装后的post和get请求：

post请求：

package com.mg.tools;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

/**
 * 接口调用post工具
 * 
 * @author admin
 *
 */
public class SendPost {
    public static void main(String[] args) {
        // 接口地址
        String url = "http://49.235.92.12:9000/api/v1/login";
        // 测试数据
        String username = "test";
        String password = "123456";
        Map<String, String> params = new HashMap<String, String>();
        // 将数据添加到map里面
        params.put("username", username);
        params.put("password", password);
        // 传入参数，调用方法发送请求
        System.out.println(sendPost(url, params));
    }

    /**
     * post请求处理接口
     * 
     * @param url：请求url地址
     * @param params：请求参数map形式添加
     * @return
     */
    public static String sendPost(String url, Map<String, String> params) {

        // 接口请求方式:post
        HttpPost post = new HttpPost(url);
        List<BasicNameValuePair> parameters = new ArrayList<BasicNameValuePair>();

        // 取出map中所有的参数名
        Set<String> keys = params.keySet();

        // 通过循环将参数保存到list集合里面
        for (String key : keys) {
            String value = params.get(key);
            parameters.add(new BasicNameValuePair(key, value));
        }
        // 定义全局变量，便于返回结果
        String result = "";

        try {
            post.setEntity(new UrlEncodedFormEntity(parameters, "utf-8"));
            // 发送请求，获取响应
            HttpClient client = HttpClients.createDefault(); // 创建默认客户端，相当于按钮
            HttpResponse response = client.execute(post);

            // 状态码
            int code = response.getStatusLine().getStatusCode();
            System.out.println("状态码：" + code);

            // 响应报文
            result = EntityUtils.toString(response.getEntity());

        } catch (Exception e) {
            e.printStackTrace();
        }

        return "响应报文：" + result;
    }

}

get请求：

package com.mg.tools;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

/**
 * 接口调用get工具
 * 
 * @author admin
 *
 */
public class SendGet {
    public static void main(String[] args) {
        // 准备url
        String url = "https://tcc.taobao.com/cc/json/mobile_tel_segment.htm";
        // 准备测试数据
        String tel = "18581232148";
        Map<String, String> params = new HashMap<String, String>();
        params.put("tel", tel);
        System.out.println(sendGet(url, params));
    }

    /**
     * @param url：请求url地址
     * @param params：请求参数map形式添加
     * @return
     */
    public static String sendGet(String url, Map<String, String> params) {

        Set<String> keys = params.keySet();
        // 标识位
        int mark = 1;
        for (String key : keys) {
            if (mark == 1) {
                url += ("?" + key + "=" + params.get(key));
            } else {
                url += ("&" + key + "=" + params.get(key));
            }
            mark++;
        }
        System.out.println("url=" + url);

        // 请求方式:get
        HttpGet get = new HttpGet(url);

        // 发送请求,获取响应
        HttpClient httpClient = HttpClients.createDefault();
        HttpResponse response;

        String result = "";

        try {
            response = httpClient.execute(get);
            // 获取响应状态码
            int code = response.getStatusLine().getStatusCode();
            System.out.println("响应状态码：" + code);

            // 获取响应内容
            result = EntityUtils.toString(response.getEntity());

        } catch (Exception e) {
            e.printStackTrace();
        }

        return "响应报文：" + result;
    }
}

HttpUtil工具类：

package com.mg.api.auto_v1;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.http.HttpResponse;
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.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

/**
 * 接口调用工具类,post和get
 * 
 * @author admin
 *
 */
public class HttpUtil {
    /**
     * post请求处理接口
     * 
     * @param url：请求url地址
     * @param params：请求参数map形式添加
     * @return
     */
    public static String sendPost(String url, Map<String, String> params) {

        // 接口请求方式:post
        HttpPost post = new HttpPost(url);
        List<BasicNameValuePair> parameters = new ArrayList<BasicNameValuePair>();

        // 取出map中所有的参数名
        Set<String> keys = params.keySet();

        // 通过循环将参数保存到list集合里面
        for (String key : keys) {
            String value = params.get(key);
            parameters.add(new BasicNameValuePair(key, value));
        }
        // 定义全局变量，便于返回结果
        String result = "";

        try {
            post.setEntity(new UrlEncodedFormEntity(parameters, "utf-8"));
            // 发送请求，获取响应
            HttpClient client = HttpClients.createDefault(); // 创建默认客户端，相当于按钮
            HttpResponse response = client.execute(post);

            // 状态码
            int code = response.getStatusLine().getStatusCode();
            System.out.println("状态码：" + code);

            // 响应报文
            result = EntityUtils.toString(response.getEntity());

        } catch (Exception e) {
            e.printStackTrace();
        }

        return "响应报文：" + result;
    }

    /**
     * get请求处理接口
     * 
     * @param url
     * @param params
     * @return
     */
    public static String sendGet(String url, Map<String, String> params) {
        Set<String> keys = params.keySet();
        // 标识位
        int mark = 1;
        for (String key : keys) {
            if (mark == 1) {
                url += ("?" + key + "=" + params.get(key));
            } else {
                url += ("&" + key + "=" + params.get(key));
            }
            mark++;
        }
        System.out.println("url=" + url);

        // 请求方式:get
        HttpGet get = new HttpGet(url);

        // 发送请求,获取响应
        HttpClient httpClient = HttpClients.createDefault();
        HttpResponse response;

        String result = "";

        try {
            response = httpClient.execute(get);
            // 获取响应状态码
            int code = response.getStatusLine().getStatusCode();
            System.out.println("响应状态码：" + code);

            // 获取响应内容
            result = EntityUtils.toString(response.getEntity());

        } catch (Exception e) {
            e.printStackTrace();
        }

        return "响应报文：" + result;
    }
}
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原文地址：https://www.cnblogs.com/xiamaojjie/p/12258902.html