在进行编码之前,我们先创建一个Servlet,该Servlet接收客户端的参数(name和age),并响应客户端。
@WebServlet(urlPatterns={"/demo.do"}) public class DemoServlet extends HttpServlet { private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String name = request.getParameter("name"); String age = request.getParameter("age"); PrintWriter pw = response.getWriter(); pw.print("您使用GET方式请求该Servlet。<br />" + "name = " + name + ",age = " + age); pw.flush(); pw.close(); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String name = request.getParameter("name"); String age = request.getParameter("age"); PrintWriter pw = response.getWriter(); pw.print("您使用POST方式请求该Servlet。<br />" + "name = " + name + ",age = " + age); pw.flush(); pw.close(); } }
java.net.HttpURLConnection是java.net.URL的子类,提供了更多的关于http的操作(getXXX 和 setXXX方法)。该类中定义了一系列的HTTP状态码:
public void post() throws IOException{ URL url = new URL("http://127.0.0.1/http/demo.do"); HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection(); httpURLConnection.setDoInput(true); httpURLConnection.setDoOutput(true); // 设置该连接是可以输出的 httpURLConnection.setRequestMethod("POST"); // 设置请求方式 httpURLConnection.setRequestProperty("charset", "utf-8"); PrintWriter pw = new PrintWriter(new BufferedOutputStream(httpURLConnection.getOutputStream())); pw.write("name=welcome"); // 向连接中输出数据(相当于发送数据给服务器) pw.write("&age=14"); pw.flush(); pw.close(); BufferedReader br = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream(),"utf-8")); String line = null; StringBuilder sb = new StringBuilder(); while ((line = br.readLine()) != null) { // 读取数据 sb.append(line + "\n"); } System.out.println(sb.toString()); }
httpclient大大简化了JDK中http通信的实现。
maven依赖:
<dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.3.6</version> </dependency>