Httpclient的使用

4.4.1 什么是httpclient HttpClient 是 Apache Jakarta Common 下的子项目，用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持 HTTP 协议最新的版本和建议。 下载地址： http://hc.apache.org/

4.4.2 添加依赖

需要把httpclient的jar包添加到工程中。只需要在工程中添加httpclient的依赖。

4.4.3 使用方法 4.4.3.1 使用httpclient执行get请求

@Test public 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httpclient response.close(); httpClient.close(); }

4.4.3.2 执行get请求带参数

@Test public 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httpclient response.close(); httpClient.close(); }

4.4.3.3 使用httpclient执行post请求

@Test public 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(); }

4.4.3.4 带参数post请求

@Test public 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(); }

4.4.4 Httpclient封装成工具类 其他项目也可能会用到httpclient，所以把工具类放到taotao-common中。