手机客户端连接服务器进行登录验证

最近两个月感觉还是学了不少东西，安卓了解更加透彻，web开发也能拿的出手，php也开始上手了。总会有不想写代码的时候，这时就来总结总结学习的东西也挺好的。

现在主要存在两种网络模式，B/S和C/S。相对于B/S，C/S可能要稍微复杂一点，需要我们开发客户端。C/S可以使用tcp/ip协议和http协议进行通信。我们从简单的开始，看一下手机客户端怎么用这两种方式连接后台验证密码成功登陆。

一、使用http协议

我们需要一个web服务器，至于这个服务器怎么搭建，用servlet+jdbc还是使用hibernate，spring这些框架都是可以实现的。这里我使用的是hibernate，新建一个web工程，hibernate配置文件代码如下：

<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <session-factory>
        <property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
        <property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
        <property name="hibernate.connection.username">XXX</property>
        <property name="hibernate.connection.password">XXX</property>
        <property name="hibernate.connection.url">jdbc:oracle:thin:@ip:port:dataname</property>
        <property name="show_sql">true</property>
     <mapping resource="com/xyj/domain/User.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

package com.xyj.hibernate;


import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.hibernate.Query;
import org.hibernate.Session;
import org.junit.Test;

import com.zifeiyu.domain.Score;
import com.zifeiyu.domain.Student;

/*
 * 提供数据库的查询服务，包括密码
 */
public class DBService {
	
	public static String getPassword(String username) {
		Session session = null;
		try {
			session = hibOracleUtils.getSession();
			String hql="from User as s where s.username=?"; 
			Query query=session.createQuery(hql);
			//填充占位符
			query.setString(0, username);
			User user=(User) query.uniqueResult();
			return user.getpassword();
		}finally {
			if (session != null) {
				session.close();
			}
		}
	}
}

服务器类：

public class LoginServlet extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		this.doPost(req, resp);
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		PrintWriter pw = resp.getWriter();
	        String username= req.getParameter("username");
		String password = req.getParameter("password");
		System.out.println("=========username========" + username);
		System.out.println("=========password========" + password);
		String PASSWD;
		try {
//根据用户名从数据库取出密码（数据库中存放的是md5加密后的密码，客户端传过来的也是加密后的，保证了安全性）
		       PASSWD = DBService.getPassword(username);
			if (password.equals(PASSWD)) {
				pw.print(true);
			} else {
				pw.print(false);
			}
		} catch (Exception e) {
			pw.print(false);
		}
	}

}

这样后台服务器就搭建好了（上面仅仅贴出了重要代码），再来看看手机客户端怎么发送http请求。

package com.xyj.login;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
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.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

public class HttpClientToServer {
	
	String urlAddress = "http://localhost:8081/AndroidServer/login.do";
	public HttpClientToServer(){
			
		}
	
	public String doPost(String USER_XH,String password){
		HttpPost httpPost = new HttpPost(urlAddress);
		List params = new ArrayList();
		NameValuePair pair1 = new BasicNameValuePair("username", username);
		NameValuePair pair2 = new BasicNameValuePair("password", password);
		params.add(pair1);
                params.add(pair2);
		HttpEntity he;
		try {
			he = new UrlEncodedFormEntity(params, "gbk");
			httpPost.setEntity(he);
		} catch (UnsupportedEncodingException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		} 
		
		
		HttpClient hc = new DefaultHttpClient();
		try {
			HttpResponse ht = hc.execute(httpPost);
			if(ht.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
				HttpEntity het = ht.getEntity();
				InputStream is = het.getContent();
				BufferedReader br = new BufferedReader(new InputStreamReader(is));
				String response = "";
				String readLine = null;
				while((readLine =br.readLine()) != null){
					//response = br.readLine();
					response = response + readLine;
				}
				is.close();
				br.close();
				
				//String str = EntityUtils.toString(he);
				System.out.println("========="+response);
				return response;
			}else{
				return "error";
			}
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return "exception";
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return "exception";
		}
	}
}

然后根据返回值是TRUE或者FALSE自定义提示消息就行了。

二、使用tcp/ip协议

服务器端使用jdbc连接数据库，代码如下：

package myServer;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class myServerSocket {

	public static void main(String[] args) {
		ServerSocket serverSocket = null;
		Socket socket = null;
		// 监听8888端口
		try {
			serverSocket = new ServerSocket(8888);
			System.out.println("服务器开启");
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		while (true) {
			try {
				// 有请求接入
				socket = serverSocket.accept();
				//开启线程处理请求
				new serverThread(socket).start();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

		}
	}

}

package myServer;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.mysql.jdbc.ResultSetMetaData;

public class serverThread extends Thread {
	public Socket socket = null;
	DataInputStream dataInputStream = null;
	DataOutputStream dataOutputStream = null;
	String[] arr;
	// 用于连接数据库
	static String DBDrive = "com.mysql.jdbc.Driver";
	static String connStr = "jdbc:mysql://localhost:3306/mydb";
	// 连接对象
	static Connection conn = null;
	// 语句对象
	PreparedStatement statement = null;
	// 查询结果对象
	ResultSet resultSet = null;

	public serverThread(Socket socket) {
		this.socket = socket;
		// 连接mysql数据库
		linkMySql();
	}

	private void linkMySql() {
		// 加载数据库驱动程序
		try {
			Class.forName(DBDrive);
			System.out.println("驱动成功");
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
		try {
			conn = DriverManager.getConnection(connStr, "XXX", "XXX");
			System.out.println("连接成功");
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	@Override
	public void run() {
		super.run();
		try {
			dataInputStream = new DataInputStream(socket.getInputStream());
			// 读取消息
			String msg = dataInputStream.readUTF();
			arr = msg.split(" ");
			System.out.println(msg);
			// 响应请求
			dataOutputStream = new DataOutputStream(
					socket.getOutputStream());
				try {
					checkInfo();
				} catch (SQLException e) {
					e.printStackTrace();
				}
		} catch (IOException e) {
			e.printStackTrace();
		}
		// 关闭相关的流
		try {
			if (dataInputStream != null)
				dataInputStream.close();
			if (dataOutputStream != null)
				dataOutputStream.close();
			if (socket != null)
				socket.close();
			if(conn!=null)
			conn.close();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	private void checkInfo() throws SQLException {
        String sql="select * from user where username=?";
        List<Object> params=new ArrayList<Object>();
        params.add(arr[0]);
        //得到该用户的所有信息
        Map<String, Object> map=findSimpleResult(sql,params);
        //输出
        System.out.println(map);
        //通过键值得到密码
        String psd=(String) map.get("psd");
        if(psd==null){
			try {
			dataOutputStream.writeUTF("该用户不存在");
		} catch (IOException e) {
			e.printStackTrace();
		}
        }else{
        	try {
				if(psd!=null&&psd.equals(arr[1]))
					dataOutputStream.writeUTF("登录成功");
				else
					dataOutputStream.writeUTF("密码有误");
			} catch (IOException e) {
				e.printStackTrace();
			}
        }
	}

	//通过用户名得到该用户的所有信息
	private Map<String, Object> findSimpleResult(String sql, List<Object> params) throws SQLException {
		Map<String, Object> map=new HashMap<String,Object>();
		int index=1;
		statement = conn.prepareStatement(sql);
		if(params!=null&&!params.isEmpty()){
			for(int i=0;i<params.size();i++){
				statement.setObject(index++, params.get(i));
			}
		}
		resultSet=statement.executeQuery();
		java.sql.ResultSetMetaData metaData=resultSet.getMetaData();
		int col_len=metaData.getColumnCount();
		while(resultSet.next()){
			for(int i=0;i<col_len;i++){
				String col_name=metaData.getColumnName(i+1);
				Object col_value=resultSet.getObject(col_name);
				if(col_value==null){
					col_value="";
				}
				map.put(col_name, col_value);
			}
		}
		return map;
	}

}

客户端代码：

package com.xyj.client;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

import com.xyj.help.config;

import android.os.Handler;
import android.os.Message;

public class loginclientThread extends Thread {
	private String name;
	private String psd;
	Handler handler;
	String response;
	Socket socket;
	DataInputStream dataInputStream;
	DataOutputStream dataOutputStream;

	public loginclientThread(String name, String psd, Handler handler) {
		this.name = name;
		this.psd = psd;
		this.handler = handler;
	}

	public void run() {
		// 创建套接字
		try {
			socket = new Socket("122.207.54.5", 8888);
		} catch (UnknownHostException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {
			dataInputStream = new DataInputStream(socket.getInputStream());
			dataOutputStream = new DataOutputStream(socket.getOutputStream());
			// 发送请求
			dataOutputStream.writeUTF(toString());
			// 得到返回消息
			response = dataInputStream.readUTF();
			Message message = Message.obtain();
			message.what = config.islogin;
			message.obj = response;
			handler.sendMessage(message);
		} catch (IOException e) {
			e.printStackTrace();
		}

		try {
			dataInputStream.close();
			dataOutputStream.close();
			socket.close();
		} catch (IOException e) {
			e.printStackTrace();
		}

	}

	@Override
	public String toString() {
//需要传送的参数多建议采用json传递
		return name + " " + psd + " ";
	}
}

以上就是这两种协议通信的主要代码。每天进步一点点，我们都可以非常棒