HttpClient之基本使用

增加依赖配置

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5</version>
</dependency>
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpcore</artifactId>
    <version>4.4.5</version>
</dependency>

package com.zns.test;

import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.apache.log4j.Logger;

public class Test {
    protected static Logger logger = Logger.getLogger(Test.class);

    public static void main(String[] args) throws Exception {
        test1();
    }

    // get请求
    public static void test1() throws Exception {
        // 创建Httpclient对象
        CloseableHttpClient httpclient = HttpClients.createDefault();
        // 创建http GET请求
        // HttpGet httpGet = new HttpGet("http://www.baidu.com/s?wd=java");

        // 含有参数
        URI uri = new URIBuilder("http://www.baidu.com/s").setParameter("wd", "java").build();
        HttpGet httpGet = new HttpGet(uri);

        CloseableHttpResponse response = null;
        try {
            // 执行请求
            response = httpclient.execute(httpGet);
            // 判断返回状态是否为200
            if (response.getStatusLine().getStatusCode() == 200) {
                // 获取服务端返回的数据
                String content = EntityUtils.toString(response.getEntity(), "UTF-8");
                System.out.println(content);
            }
        } finally {
            if (response != null) {
                response.close();
            }
            httpclient.close();
        }
    }

    // post请求
    public static void test2() throws Exception {
        // 创建Httpclient对象
        CloseableHttpClient httpclient = HttpClients.createDefault();
        // 创建http POST请求
        HttpPost httpPost = new HttpPost("http://www.xxx.com/search");

        // 设置请求参数
        List<NameValuePair> parameters = new ArrayList<NameValuePair>();
        parameters.add(new BasicNameValuePair("id", "1"));
        parameters.add(new BasicNameValuePair("name", "abc"));
        // 构造一个form表单式的实体
        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);
        // 将请求实体设置到httpPost对象中
        httpPost.setEntity(formEntity);

        // 如果是JSON数据
        // String jsonBody="";
        // StringEntity jsonEntity = new StringEntity(jsonBody, "utf-8");
        // jsonEntity.setContentType("application/json");
        // httpPost.setEntity(jsonEntity);

        // 伪装浏览器请求
        httpPost.setHeader("User-Agent",
                "Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.118 Safari/537.36");
        CloseableHttpResponse response = null;
        try {
            // 执行请求
            response = httpclient.execute(httpPost);
            // 判断返回状态是否为200
            if (response.getStatusLine().getStatusCode() == 200) {
                // 获取服务端返回的数据
                String content = EntityUtils.toString(response.getEntity(), "UTF-8");
                System.out.println(content);
            }
        } finally {
            if (response != null) {
                response.close();
            }
            httpclient.close();
        }
    }
}