HttpClient4.x工具可以让我们输入url,就可以请求某个页面(个人感觉挺实用的,特别是封装在代码中)

首先我们需要在maven工程中添加依赖

<dependency>                 <groupId>org.apache.httpcomponents</groupId>                 <artifactId>httpclient</artifactId>                 <version>4.5.3</version>             </dependency>             <dependency>                 <groupId>org.apache.httpcomponents</groupId>                 <artifactId>httpmime</artifactId>                 <version>4.5.2</version>             </dependency>
              <dependency>                 <groupId>commons-codec</groupId>                 <artifactId>commons-codec</artifactId>             </dependency>             <dependency>                 <groupId>commons-logging</groupId>                 <artifactId>commons-logging</artifactId>                 <version>1.1.1</version>             </dependency>                     <dependency>                     <groupId>org.apache.httpcomponents</groupId>                     <artifactId>httpcore</artifactId>             </dependency>
 
          <!-- gson工具，封装http的时候使用 -->         <dependency>             <groupId>com.google.code.gson</groupId>             <artifactId>gson</artifactId>             <version>2.8.0</version>         </dependency>   接下来,我们来封装一下,有get/post请求

 1 /** 2 * 封装http get post 3 */ 4 public class HttpUtils { 5  6 private static final Gson gson = new Gson(); 7 /** 8 * get方法 9 */10 public static Map<String,Object> doget(String url,int timeout){11 Map<String,Object> map = new HashMap<>();12 CloseableHttpClient httpClient = HttpClients.createDefault();
　　//配置可有可无,根据个人情景13 RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(timeout) //设置连接超时时间14 .setConnectionRequestTimeout(timeout) //设置请求超时时间15 .setSocketTimeout(timeout)16 .setRedirectsEnabled(true) //设置允许自动重定向17 .build();1819 HttpGet httpGet = new HttpGet(url);20 httpGet.setConfig(requestConfig);21 22 try {23 HttpResponse httpResponse = httpClient.execute(httpGet);24 if(httpResponse.getStatusLine().getStatusCode() == 200){25 String jsonResult = EntityUtils.toString(httpResponse.getEntity());26 map = gson.fromJson(jsonResult, map.getClass()); //通过gson工具,将响应流转换成map集合27 }28 29 }catch(Exception e){30 e.printStackTrace();31 }finally{32 try{33 httpClient.close();34 }catch(Exception e) {35 e.printStackTrace();36 }37 }38 return map;39 }40 /**41 * 封装post,与get有异曲同工之妙42 */43 public static String dopost(String url,String data,int timeout){44 CloseableHttpClient httpClient = HttpClients.createDefault();45 RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(timeout) //设置连接超时46 .setConnectionRequestTimeout(timeout) //设置请求超时47 .setRedirectsEnabled(true) //设置允许自动重定向48 .build();49 50 HttpPost httpPost = new HttpPost(url);51 httpPost.setConfig(requestConfig);52 httpPost.addHeader("Content-Type","text/html; chartset=UTF-8"); //添加头信息53 if (data != null && data instanceof String) {//使用字符串传参54 StringEntity stringEntity = new StringEntity(data, "UTF-8");55 httpPost.setEntity(stringEntity);56 }57 try {58 CloseableHttpResponse httpResponse = httpClient.execute(httpPost);59 HttpEntity httpEntity = httpResponse.getEntity();60 if (httpResponse.getStatusLine().getStatusCode() == 200){61 String result = EntityUtils.toString(httpEntity);62 return result;63 }64 } catch (Exception e) {65 e.printStackTrace();66 }finally {67 try{68 httpClient.close();69 }catch (Exception e){70 e.printStackTrace();71 }72 }73 74 return null;75 76 }77 }

封装好HttpClient工具后,我们来调用一下

get请求

HttpUtils.doget(请求地址,请求时间(timeout));

post请求

HttpUtils.dopost(请求地址, 请求传的数据(传之前需要转换成string), 请求时间(timeout));