一:什么是HttpClient？

主要是模拟浏览器发送请求给server，监听响应信息，推断返回结果的正确性怎样，因为避开的浏览器的UI
，也就将浏览器中全部载入的时间（比方常常要载入图片啊）都省掉了，所以这个运行效率相当高

二. 使用HttpClient

1.get请求

@Testpublic void doGet() throws Exception {//创建一个httpclient对象CloseableHttpClient httpClient = HttpClients.createDefault();//创建一个GET对象HttpGet get = new HttpGet("http://www.sogou.com");//执行请求CloseableHttpResponse response = httpClient.execute(get);//取响应的结果int statusCode = response.getStatusLine().getStatusCode();System.out.println(statusCode);HttpEntity entity = response.getEntity();String string = EntityUtils.toString(entity, "utf-8");System.out.println(string);//关闭httpclientresponse.close();httpClient.close();}

2.带参数的get请求

@Testpublic void doGetWithParam() throws Exception{//创建一个httpclient对象CloseableHttpClient httpClient = HttpClients.createDefault();//创建一个uri对象URIBuilder uriBuilder = new URIBuilder("http://www.sogou.com/web");uriBuilder.addParameter("query", "花千骨");HttpGet get = new HttpGet(uriBuilder.build());//执行请求CloseableHttpResponse response = httpClient.execute(get);//取响应的结果int statusCode = response.getStatusLine().getStatusCode();System.out.println(statusCode);HttpEntity entity = response.getEntity();String string = EntityUtils.toString(entity, "utf-8");System.out.println(string);//关闭httpclientresponse.close();httpClient.close();}

3.post请求

@Testpublic void doPost() throws Exception {CloseableHttpClient httpClient = HttpClients.createDefault();//创建一个post对象HttpPost post = new HttpPost("http://localhost:8082/httpclient/post.html");//执行post请求CloseableHttpResponse response = httpClient.execute(post);String string = EntityUtils.toString(response.getEntity());System.out.println(string);response.close();httpClient.close();}

4.带参数的post请求

@Testpublic void doPostWithParam() throws Exception{CloseableHttpClient httpClient = HttpClients.createDefault();//创建一个post对象HttpPost post = new HttpPost("http://localhost:8082/httpclient/post.html");//创建一个Entity。模拟一个表单List<NameValuePair> kvList = new ArrayList<>();kvList.add(new BasicNameValuePair("username", "zhangsan"));kvList.add(new BasicNameValuePair("password", "123"));//包装成一个Entity对象StringEntity entity = new UrlEncodedFormEntity(kvList, "utf-8");//设置请求的内容post.setEntity(entity);//执行post请求CloseableHttpResponse response = httpClient.execute(post);String string = EntityUtils.toString(response.getEntity());System.out.println(string);response.close();httpClient.close();}