httpclient工具使用(org.apache.httpcomponents.httpclient)

原文地址：https://www.cnblogs.com/achengmu/p/11075007.html

httpclient工具使用(org.apache.httpcomponents.httpclient)

引入依赖

<dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.3.5</version>
    </dependency>

get请求

public static void main(String[] args) throws Exception {
         
        //创建httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //创建Http get请求
        HttpGet httpGet = new HttpGet("http://www.xxx.com/rest/content?categoryId=4&page=1&rows=20");
        //接收返回值
        CloseableHttpResponse response = null;
         
        try {
            //请求执行
            response = httpClient.execute(httpGet);
            if(response.getStatusLine().getStatusCode()==200){
                String content = EntityUtils.toString(response.getEntity(), "utf-8");
                System.out.println("--------->" + content);
            }
        }finally{
            if(response!=null){
                response.close();
            }
            httpClient.close();
        }

get带参数请求

public static void main(String[] args) throws Exception{
         
        //创建httpClient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //定义http get参数
        URI uri = new URIBuilder("http://www.xxxx.com/rest/content").setParameter("categoryId", "4")
                .setParameter("page", "1").setParameter("rows", "30").build();
        System.out.println(uri);
        //创建http get请求
        HttpGet httpGet = new HttpGet(uri);
         
        //接受请求返回的定义
        CloseableHttpResponse response = null;
        try {
            //执行get请求
            response = httpClient.execute(httpGet);
            if(response.getStatusLine().getStatusCode()==200){
                String content = EntityUtils.toString(response.getEntity(), "utf-8");
                System.out.println(content);
            }
        }finally{
            if(response!=null){
                response.close();
            }
            httpClient.close();
        }
    }

http post请求

public static void main(String[] args) throws Exception {
 
       // 创建Httpclient对象
       CloseableHttpClient httpclient = HttpClients.createDefault();
 
       // 创建http POST请求
       HttpPost httpPost = new HttpPost("http://www.oschina.net/");
       // 伪装成浏览器
       httpPost.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 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) {
               String content = EntityUtils.toString(response.getEntity(), "UTF-8");
               System.out.println(content);
           }
       } finally {
           if (response != null) {
               response.close();
           }
           httpclient.close();
       }
 
   }

http post带参数请求

public static void main(String[] args) throws Exception{
        //创建httpclient
        CloseableHttpClient httpClient = HttpClients.createDefault();
        //创建http post
        HttpPost httpPost = new HttpPost("http://www.oschina.net/search");
        //模拟浏览器设置头
        httpPost.setHeader(
                "User-Agent",
                "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36");
     
        //设置请求数据
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("scope", "project"));
        params.add(new BasicNameValuePair("q", "java"));
        params.add(new BasicNameValuePair("fromerr", "7nXH76r7"));
        //构建表单
        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(params);
        //将表达请求放入到httpost
        httpPost.setEntity(formEntity);
         
        //返回类型
        CloseableHttpResponse response = null;
         
        try {
            response = httpClient.execute(httpPost);
            String content = EntityUtils.toString(response.getEntity(), "utf-8");
            System.out.println(content);
        }finally{
            if(response!=null){
                response.close();
            }
            httpClient.close();
        }
         
     
    }