客户端的代码是：
package lgx.java.test;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.UnsupportedEncodingException;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.HttpClient;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.message.BasicNameValuePair;public class HttpClientDemo {/** * @param args */public static void main(String[] args) {String path = ":8080/myapp2/LoginAction";Map<String, String> params = new HashMap<String, String>();params.put("username", "admin");params.put("password", "123");String result =sendClientPostMessage(path, params, "utf-8");System.out.println("–>>"+result);}private static String sendClientPostMessage(String path,Map<String,String> param,String encode) {List<NameValuePair> list=new ArrayList<NameValuePair>();String result="";if(param!=null&&!param.isEmpty()){for(Map.Entry<String, String> entry:param.entrySet()){list.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));}}try {//实现将请求的参数封装到表单中，，请求体中UrlEncodedFormEntity entity=new UrlEncodedFormEntity(list, encode);//使用post提交数据HttpPost httpPost=new HttpPost(path);//设置使用的EntityhttpPost.setEntity(entity);HttpClient client=new DefaultHttpClient();//客户端开始向指定的网址发送请求HttpResponse response=client.execute(httpPost);result= StreamToString(response.getEntity().getContent(),encode);} catch (UnsupportedEncodingException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (ClientProtocolException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}return result;}/** * 将一个输入流转换成指定编码的字符串 * * @param inputStream 输入流 * @param encode 编码格式 * @return 字符串 */private static String StreamToString(InputStream inputStream, String encode) {ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();byte[] data = new byte[1024];String result = "";int len = 0;try {while ((len = inputStream.read(data)) != -1) {arrayOutputStream.write(data, 0, len);}result = new String(arrayOutputStream.toByteArray(), encode);} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}return result;}}服务端的代码是：package com.login.manager;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class LoginAction */public class LoginAction extends HttpServlet {private static final long serialVersionUID = 1L;/*** Default constructor.*/public LoginAction() {// TODO Auto-generated constructor stub}/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// TODO Auto-generated method stubthis.doPost(request, response);}/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {response.setContentType("text/html;charset=utf-8");request.setCharacterEncoding("utf-8");response.setCharacterEncoding("utf-8");PrintWriter out=response.getWriter();String username=request.getParameter("username");String password=request.getParameter("password");System.out.println(username+"—->username");System.out.println(password+"—–>password");if(username.equals("admin")&&password.equals("123")){out.print("longin is success");}else{out.print("login is failed");}}}客户端的控制台：
–>>longin is success
服务端的控制台：
admin—->username123—–>password
下一篇文章，我将写通过Apache的httpClient的get方式连接服务器。
其实只要你愿意，一切都可以变得很容易。
