JAVA数据查询返回结果集_java socket编程，客户端发出检索字段，服务端查询数据并返回结果集...

1.服务器端

/**

*

*/

import java.io.*;

import java.net.*;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.*;

import java.util.concurrent.*;

import com.mysql.jdbc.PreparedStatement;

/**

* @author linzhifeng

*

*/

public class Server{

//服务器端 需要单独编译并在命令行模式下启动测试

public static final String DBDRIVER = "com.mysql.jdbc.Driver";

public static final String DBURL = "jdbc:mysql://localhost:3306/jdbc";

public static final String DBUSER = "root";

public static final String DBPASSWORD = "123456";

private static final int SERVERPORT = 54323; //服务器端口

private static List mClientList = new ArrayList(); //客户端连接 通过List来储存所有连接进来的客户端的Socket对象(也可用CopyOnWriteArrayList来储存)

private ExecutorService mExecutorService;  //线程池 需要为每个客户端都开启一个线程

private ServerSocket mServerSocket;  //ServerSocket对象

public static void main(String[] args){ //main方法 开启服务器

new Server();

}

public Server(){

try{

mServerSocket = new ServerSocket(SERVERPORT);//设置服务器端口

mExecutorService = Executors.newCachedThreadPool();//创建一个线程池

System.out.println("start...");

Socket client = null;//用来临时保存客户端连接的Socket对象

while (true){

client = mServerSocket.accept(); //接收客户连接并添加到list中

mClientList.add(client);

mExecutorService.execute(new ThreadServer(client));//开启一个客户端线程

}

}catch (IOException e){

e.printStackTrace();

}

}

static class ThreadServer implements Runnable{//每个客户端单独开启一个线程

private Socket   mSocket;

private BufferedReader mBufferedReader;

private PrintWriter  mPrintWriter;

private String   mStrMSG;

public ThreadServer(Socket socket) throws IOException{

this.mSocket = socket;

mBufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));

mStrMSG = "user:"+this.mSocket.getInetAddress()+" come total:" + mClientList.size();

sendMessage();

}

public void run(){

try{

while ((mStrMSG = mBufferedReader.readLine()) != null){

if (mStrMSG.trim().equals("exit")){

//当一个客户端退出时

mClientList.remove(mSocket);

mBufferedReader.close();

mPrintWriter.close();

mStrMSG = "user:"+this.mSocket.getInetAddress()+" exit total:" + mClientList.size();

mSocket.close();

sendMessage();

break;

}else{

String name=mStrMSG;

mStrMSG = mSocket.getInetAddress() + ":" + mStrMSG;

Connection con = null;

try {

Class.forName(DBDRIVER);

con = DriverManager.getConnection(DBURL, DBUSER, DBPASSWORD);

Statement str = con.createStatement();

//String name="china";

String sql = "select id from test where country = '"+name+"' limit 0,10";

PreparedStatement st = (PreparedStatement) con.prepareStatement(sql);

java.sql.ResultSet rs=null;

rs = st.executeQuery(sql);

while(rs.next()){

System.out.println(rs.getString("id"));

mStrMSG+="|"+rs.getString("id");

}

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

sendMessage();

}

}

}catch (IOException e){

e.printStackTrace();

}

}

private void sendMessage() throws IOException{//发送消息给所有客户端

System.out.println(mStrMSG);

for (Socket client : mClientList){

mPrintWriter = new PrintWriter(client.getOutputStream(), true);

mPrintWriter.println(mStrMSG);

}

}

}

}

2.客户端

/**

*

*/

package HTTP;

import java.io.*;

import java.net.Socket;

import java.util.concurrent.*;

/**

* @author linzhifeng

*

*/

public class client{//需要单独编译并在命令行模式下启动测试

private static final int  PORT = 54323;

private static ExecutorService exec = Executors.newCachedThreadPool();

public static void main(String[] args) throws Exception{

new client();

}

public client(){

try{

Socket socket = new Socket("127.0.0.1", PORT);

exec.execute(new Sender(socket));

BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));

String msg;

while ((msg = br.readLine()) != null){

System.out.println(msg);

}

}catch (Exception e){

}

}

static class Sender implements Runnable{//客户端线程获取控制台输入消息

private Socket socket;

public Sender(Socket socket){

this.socket = socket;

}

public void run(){

try{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

PrintWriter pw = new PrintWriter(socket.getOutputStream(), true);

String msg;

while (true){

msg = br.readLine();

pw.println(msg);

if (msg.trim().equals("exit")){

pw.close();

br.close();

exec.shutdownNow();

break;

}

}

}catch (Exception e){

e.printStackTrace();

}

}

}

}

3.cmd下编译运行服务器

javac -cp mysql-connector-java-5.0.8-bin.jar ./Server.java

java -cp mysql-connector-java-5.0.8-bin.jar Server