package com.server.servelt;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.Base64;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.server.service.UserService;
import com.sun.mail.util.BASE64DecoderStream;
public class UserManager extends HttpServlet {
private static final String CODE="UTF-8";
public UserManager()
{
super();
}
public void destroy()
{
super.destroy();
}
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException
{
doPost(request, response);
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException
{
//设置编码
response.setContentType("text/html");
response.setCharacterEncoding(CODE);
request.setCharacterEncoding(CODE);
//获取请求方法名,其中request_flag是我们安卓客户端请求的参数，详细介绍请参照servlet有关书籍
String flag=request.getParameter("request_flag");
System.out.println("flag="+flag);
//预定义一个字符串，用来接收json
String json="";
if("login".equals(flag))
{
//此处的username和password也是安卓客户端访问网址的参数
String username=request.getParameter("username");
String password=request.getParameter("password");
//调用UserService的login方法实现登录
json=UserService.login(username, password);
}
//控制台输出，方便检验，无特殊含义
System.out.println("json="+json);
//利用输出流将登录信息（此处为success或是fail）反馈给客户端
PrintWriter out=response.getWriter();
out.write(json);
out.flush();
out.close();
}
}

接着是上面调用到的 UserService类

package com.server.service;
import com.server.dao.UserDao;
import com.server.util.JSONUtil;
public class UserService {
public static String login(String username,String password)
{
//调用UserDao的login方法，该方法会查询数据库并对结果进行检测，若存在该用户，返回该用户在数据库中的位置，否则，返回0（位置从一开始）
int r=UserDao.login(username,password);
//将结果一JSONObject的形式记录下来并返回让输出流反馈给客户端
String result=JSONUtil.createJSONString("result",r);
return result;
}
}

再接着是上面调用到的 UserDao类

package com.server.dao;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import com.server.util.DBUtil;
public class UserDao {
private static Connection conn=null;
private static Statement sta=null;
private static ResultSet res=null;
public UserDao()
{
}
public static int login(String username,String password)
{
try{
conn=DBUtil.getConnection();
sta=conn.createStatement();
//注意下面的sql语句，值前后要加上单引号，同时不准存在中文字符
String sql="select COUNT(*) from userlist where username='"+username+"' and +password='"+password+"'";
res=sta.executeQuery(sql);
int result=0;
if(res!=null)
{
//不断查询，若存在，返回用户在数据库中的位置，否则返回0，下面的1代表数据库的第一列，此列为自增序号列
while(res.next())
result=res.getInt(1);
}
return result;
}catch(Exception e){
e.printStackTrace();
}
return 0;
}
}

然后是俩个工具类

package com.server.util;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class DBUtil {
//默认接口是3306，除非你做了修改哈
private static final String URL="jdbc:mysql://localhost:3306/data";
//下面是你的用户名，默认为root
private static final String USERNAME="root";
//在密码出填入你的密码
private static final String PASSWORD="密码";
static{
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO: handle exception
e.printStackTrace();
}
}
public static Connection getConnection()
{
try {
return DriverManager.getConnection(URL,USERNAME,PASSWORD);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return null;
}
public void closeDB(Connection conn,Statement statement,ResultSet res)
{
try{
if(res!=null)
{
res.close();
}
if(statement!=null)
{
statement.close();
}
if(conn!=null)
{
conn.close();
}
}catch(Exception e){
e.printStackTrace();
}
}
}

package com.server.util;
import net.sf.json.JSONObject;
public class JSONUtil {
public static String createJSONString(String key ,Object value)
{
JSONObject jsonObject=new JSONObject();
jsonObject.put(key, value);
return jsonObject.toString();
}
}

另外，在WebRoot的相关路径（详细路径参考图片）需添加以下包

This is the description of my J2EE componentThis is the display name of my J2EE componentUserManagercom.server.servelt.UserManagerUserManager/servlet/UserManagerindex.jsp

package com.example.servertestandroid;
import java.io.IOException;
import com.example.util.HttpUtil;
import com.example.util.JSONUtil;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity {
//安卓客户端是以网址的方式访问服务器，此处的ip地址即为本机地址
//这里的路径其实 就是我们上面的网址，只不过在安卓中不支持localhost，所以必须写成实质性的地址
//另外，电脑应该链接网线，而手机使用电脑开启的WiFi，俩者都用WiFi似乎不行
public static final String REQUEST_URL = "http://ip:8080/AndroidWebService/servlet/UserManager?";
private String username="";
private String userpwd="";
private EditText editTextUsername,editTextUserpwd;
private Button buttonLogin;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
//初始化控件
initViews();
}
private void initViews() {
// TODO Auto-generated method stub
editTextUsername=(EditText) findViewById(R.id.id_username);
editTextUserpwd=(EditText) findViewById(R.id.id_userpwd);
//此处我直接将俩个输入框中文字设置成相应的用户名和密码，懒得码字了
editTextUsername.setText("admin");
editTextUserpwd.setText("123");
buttonLogin=(Button) findViewById(R.id.id_login);
buttonLogin.setOnClickListener(clickListener);
}
private OnClickListener clickListener=new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String username=editTextUsername.getText().toString();
String password=editTextUserpwd.getText().toString();
//设置参数
final String params="request_flag=login&username="+username+"&password="+password;
//开启线程，避免影响界面与用户的交互
new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
//通过开启httpConnection来达到访问网址的目的，此处的result即为服务端出发送的json
String result = HttpUtil.sendGet(REQUEST_URL, params);
//将上述json进行解析，得到结果（序号）
int res=JSONUtil.getResult("result", result);
if(res==1)
{
//线程中不能进行与界面交互，所以我们开启一个handler来处理
handler.sendEmptyMessage(1);
}
}
//注意此处还有 一个start（）
}).start();
}
};
Handler handler=new Handler()
{
public void handleMessage(Message message)
{
Toast.makeText(getApplicationContext(), "success",Toast.LENGTH_SHORT).show();
}
};
}

package com.example.util;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
public class HttpUtil {
public HttpUtil()
{
}
public static String sendGet(String request_url,String params)
{
try {
URL url = new URL(request_url+params);
HttpURLConnection httpURLConnection=(HttpURLConnection) url.openConnection();
httpURLConnection.setConnectTimeout(3000);
httpURLConnection.setRequestMethod("GET");
//据我的理解，应该是设置该链接是用来接收数据的，因为还有一个方法是setDoIOutput
httpURLConnection.setDoInput(true);
//200代表HTTP_OK,可以通过鼠标移至给方法上后右键或是按下F3查看声明
if(httpURLConnection.getResponseCode()==200)
{
return InputStream2String(httpURLConnection.getInputStream());
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return "";
}
private static String InputStream2String(InputStream inputStream) throws IOException {
// TODO Auto-generated method stub
ByteArrayOutputStream byteArrayOutputStream=new ByteArrayOutputStream();
int len=0;
byte[] b=new byte[1024];
//将服务端发过来的数据读取到b中
while((len=inputStream.read(b))!=-1)
{
byteArrayOutputStream.write(b, 0, len);
}
return new String(byteArrayOutputStream.toByteArray());
}
}

package com.example.util;
import org.json.JSONException;
import org.json.JSONObject;
public class JSONUtil {
/**
* 解析Json数据
* @param key
* @param json
* @return
*/
public static int getResult(String key,String json){
try {
JSONObject jsonObject=new JSONObject(json);
int result=jsonObject.getInt(key);
return result;
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return -1;
}
}