网上有很多例子来演示Android客户端和服务器端数据如何实现交互不过这些例子大多比较繁杂，对于初学者来说这是不利的，现在介绍几种代码简单、逻辑清晰的交互例子，本篇博客介绍第四种：
一、服务器端：
代码1：添加名为“AndroidServerServlet.java”的文件
package com.ghj.packageofservlet;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;public class AndroidServerServlet extends HttpServlet { private static final long serialVersionUID = 6792396567928634227L; public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { response.setContentType("text/plain; charset=UTF-8"); request.setCharacterEncoding("UTF-8"); System.err.println(request.getParameter("clientData")); PrintWriter printWriter = response.getWriter(); printWriter.print("您好Android客户端！"); printWriter.flush(); printWriter.close(); }}代码2：修改名为“web.xml”的文件
<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <servlet> <servlet-name>AndroidServerServlet</servlet-name> <servlet-class>com.ghj.packageofservlet.AndroidServerServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>AndroidServerServlet</servlet-name> <url-pattern>/AndroidServerServlet</url-pattern> </servlet-mapping></web-app>
二、Android手机客户端：
代码1：下载名为android-async-http-1.4.6.jar的jar文件，下载地址：http://download.csdn.net/download/wangshuxuncom/8116169
代码2：添加名为“AndroidClientActivity.java”的文件
package com.example.androidclient;import org.apache.http.Header;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.Toast;import com.loopj.android.http.AsyncHttpClient;import com.loopj.android.http.AsyncHttpResponseHandler;import com.loopj.android.http.RequestParams;public class AndroidClientActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.android_client); Button sendButton = (Button) findViewById(R.id.send_button); sendButton.setOnClickListener(new OnClickListener(){ @Override public void onClick(View v) { RequestParams requestParams = new RequestParams(); requestParams.add("clientData", "您好服务器端！"); new AsyncHttpClient().post("http://172.16.99.207:8080/AndroidServer/AndroidServerServlet", requestParams, new AsyncHttpResponseHandler() { @Override public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) { if(statusCode == 200){ Toast.makeText(AndroidClientActivity.this, new String(responseBody), Toast.LENGTH_LONG).show(); } } @Override public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) { Toast.makeText(AndroidClientActivity.this, "没有获取到Android服务器端的响应！", Toast.LENGTH_LONG).show(); } }); } }); }} 代码3：添加名为“android_client.xml”的文件
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MainActivity" > <Button android:id="@+id/send_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_centerVertical="true" android:text="@string/hello_server" /></RelativeLayout>
【0分下载该Demo】
说明：使用android-async-http-1.4.6.jar jar这种形式实现Android客户端和服务器端数据交互是最常用的
。