在下写的serversock和socket代码,服务器能够成功接收客户端的信息,并处理相关业务,但就是无法返回信息给客户端,还望各位老师指教

Question

在下写的serversock和socket代码,服务器能够成功接收客户端的信息,并处理相关业务,但就是无法返回信息给客户端,还望各位老师指教//SERVER端
package testsocket;
import java.lang.*;
import java.io.*;
import java.net.*;
import java.sql.*;public class newmain extends javax.swing.JFrame {   //服务器端主窗体
       public static String lr="";  //用于存放客户端传来的信息中的某一个字符串
    public newmain() {
        initComponents();
    }
    
                       
    private void initComponents() {//        此处窗体构造部分忽略
    }                       
    
    public static void main(String args[]) throws IOException{
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run()  {
                new newmain().setVisible(true);
                
            }
        });
        ServerSocket s=new ServerSocket(8056);
        while(true){
            Socket socket=s.accept();//无限监听客户的请求
                      
                  try
                  {
                      new Ctosthread(socket);//创建新线程
                  }
                  catch(IOException e)
                  {
                      socket.close();
                  }      
      }
    }
    
    // 变量声明 - 不进行修改                     
    private javax.swing.JLabel jLabel1;
    private javax.swing.JScrollPane jScrollPane1;
    public static javax.swing.JTextArea jta1;
    // 变量声明结束                   
    
}
class Ctosthread extends java.lang.Thread  //此类用于接收client发来的信息  ,此类能够成功接收,并在服务器端根据接收值进行数据库处理
{
    private Socket ts;
    private BufferedReader in;//定义输入流
    private PrintWriter out;//定义输出流
    private boolean flag=false;
    private java.sql.ResultSet rs;
   
        public Ctosthread(Socket socket) throws IOException 
        {
            this.ts=socket;
            in=new BufferedReader(new InputStreamReader(ts.getInputStream()));//创建输入流
            start();//启动线程
        }
        
        public void run()
        {
            if(!flag)
            {
                flag=true;
                try
                {
                    String lineStr = in.readLine();
                   
                   if(lineStr.toString().startsWith("注册"))
                    {
                       newmain.lr="注册";
                        String reginsert="insert into info values('";                        
                        for(int i=1;i<lineStr.toString().split(",").length;i++)
                        {
                            reginsert+=lineStr.toString().split(",")[i].toString()+"','";
                        }                           reginsert+="否','";
                           String clientip=ts.getInetAddress().toString();
                           reginsert+=clientip+"','";                           String clientport=String.valueOf(ts.getPort());
                           reginsert+=clientport+"','";                           try{
                            Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
                            String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=hhdb";
                                String user="sa";
                                String password="135ade";
                                Connection con=java.sql.DriverManager.getConnection(url,user,password);
                                Statement stmt=con.createStatement();
                                String sql="SELECT MAX(CONVERT(int, no)) AS hhno FROM info";
                                rs=stmt.executeQuery(sql);  
                                while(rs.next())
                                {
                                    if(rs.getString(1)==null)
                                    {
                                        reginsert+="1')";
                                    }
                                    else
                                    {
                                        int newno=Integer.parseInt(rs.getString(1))+1;
                                        reginsert+=String.valueOf(newno)+"')";
                                    }
                                }
                                stmt.executeUpdate(reginsert);
                               }
                               catch(Exception err)
                               {
                                   err.printStackTrace();
                               }
                    }
                    if(newmain.lr=="")//如果主类(窗体类中的String类型变量 lr值依然为空,就启用回发client端类)
                    {
                        serversend ssd=new serversend(ts,newmain.lr);
                        ssd.start();
                    }
                }
                catch(Exception ex)
                {
                    ex.printStackTrace();
                }
            }
        }
} class serversend extends Thread  //此类用于向cleint端回发信息  此类不能成功,client端无法接收服务器回传来的信息
{
        PrintWriter outy;
        Socket sendsocket;
        String se="";
        public serversend(Socket socket,String s) //此处传入的s即是主窗体中的lr值
        {
            this.sendsocket=socket;
            this.outy=null;
            this.se=s;
        }
    public void run() 
    {
           
        if(se=="")  //如果主窗体类的lr值为空
        {
            try{
                outy=new PrintWriter(new BufferedWriter(new OutputStreamWriter(sendsocket.getOutputStream())),true);//创建输出流
                        
                           System.out.println("运行到else了");
                        
                        outy.write("返回给client来了\n");
                        
                        outy.flush();     
                        sendsocket.close();
                        }
            catch(Exception ex)
            {
                
            }
        }
    }
}
/* 
 报错如下:
     java.net.SocketException: Connection reset
        at java.net.SocketInputStream.read(SocketInputStream.java:168)
        at sun.nio.cs.StreamDecoder$CharsetSD.readBytes(StreamDecoder.java:411)
        at sun.nio.cs.StreamDecoder$CharsetSD.implRead(StreamDecoder.java:453)
        at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:183)
        at java.io.InputStreamReader.read(InputStreamReader.java:167)
        at java.io.BufferedReader.fill(BufferedReader.java:136)
        at java.io.BufferedReader.readLine(BufferedReader.java:299)
        at java.io.BufferedReader.readLine(BufferedReader.java:362)
        at testsocket.Ctosthread.run(newmain.java:125)
生成成功（总时间：25 秒）
*/

Answer 1

此回复为自动发出,仅用于显示而已，并无任何其他特殊作用
楼主【cqandy】截止到2008-07-29 16:05:02的历史汇总数据(不包括此帖)：
发帖的总数量:15                       发帖的总分数:500                      每贴平均分数:33                       
回帖的总数量:14                       得分贴总数量:1                        回帖的得分率:7%                       
结贴的总数量:15                       结贴的总分数:500                      
无满意结贴数:1                        无满意结贴分:50                       
未结的帖子数:0                        未结的总分数:0                        
结贴的百分比:100.00%               结分的百分比:100.00%                  
无满意结贴率:6.67  %               无满意结分率:10.00 %                  
敬礼!

Answer 2

//client端程序package hhchat;
import java.awt.Color;
import java.util.Iterator;
import java.util.Vector;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.tree.*;
import javax.swing.tree.DefaultTreeModel;
import java.sql.*;
import java.net.*;
import java.io.*;
import java.lang.*;public class chatpanel extends javax.swing.JFrame implements Runnable{
    javax.swing.tree.DefaultMutableTreeNode dmtn=new javax.swing.tree.DefaultMutableTreeNode("root");
    javax.swing.tree.DefaultTreeModel dtm=null;
    java.sql.ResultSet rs;
    
    public static String sessionno;
    public static String sessionpwd;
    
    
    Socket link_server=new Socket();
    String link_sports="8056";
    java.net.SocketAddress link_sa=null;
    
    BufferedWriter link_bwout=null;
    BufferedReader link_in=null;
    
    
    String link_server_ip=null;
    
    boolean flag=false;    public chatpanel() {
        initComponents();
        jLabel1.setText(Main.sessionno.toString().trim());
        this.getContentPane().setBackground(Color.WHITE);        
        dtm=new DefaultTreeModel(dmtn);
        
        dtm.setRoot(dmtn);
        jTree1.setModel(dtm);
        jScrollPane1.setBorder(null);
    }
    
    public void run()
    {  
        System.out.println("chatpanel运行了");//这里能正常打印出来
        String send_info=Main.flag.toString().trim()+","+Main.sessionno.toString().trim()+","+Main.sessionpwd.toString().trim();
        
        try{
        link_server_ip=java.net.InetAddress.getByName("www.abc.net").getHostAddress().toString();
        link_sa=new java.net.InetSocketAddress(link_server_ip,java.lang.Integer.parseInt(link_sports));        link_server.connect(link_sa);
        
        
        
        link_bwout.write(send_info);
        link_bwout.flush();
        link_in=new BufferedReader(new InputStreamReader(link_server.getInputStream()));
        System.out.println(send_info);
        String readstr=null;
       if(true)
       {
            System.out.println("到ifelse了");//这里能正常打印出来
            readstr=link_in.readLine();
            System.out.println("值来了:"+readstr);
            
       }
       link_bwout.close();
        
        link_server.close();
        }
        catch(Exception e)
        {
            
        }
        
        
       
    }
    
                      
    private void initComponents() {
       //此处窗体构造,忽略
    }                      
    
    
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new chatpanel().setVisible(true);
                
            }
        });
        
    }    
    
    // 变量声明 - 不进行修改                     
    private javax.swing.JLabel jLabel1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTree jTree1;
    // 变量声明结束                   
    
}

Answer 3

你的服务器端程序不全啊？应该有部分While循环去等待客户端来连的，没有那部分，看不出你的Socket处理有没有问题。另外觉得你用一层Thread就应该够了，为什幺用两层啊？我的Socket服务器端程序，好用的。你可以忽略业务部分，只看Socket部分就可以了。public class IndexSeeker implements Runnable{
    
    protected static Logger m_Logger;

    protected String   m_szIP ;
    protected int      m_nPort;
    
    private ServerSocket serverSocket;
    private ExecutorService executorService;//线程池
    private final int POOL_SIZE=10;//单个CPU线程池大小
    
    protected static String FIELD_TITLE = "Description";
    protected static String FIELD_ID = "JobID";
    protected static String INDEX_STORE_PATH = "E:\\Baizeju\\Index";
    
    public IndexSeeker( ) {
        Logger.initialLogger();
        m_Logger = new Logger();
    }
    public IndexSeeker( String szIP, int nPort ) throws IOException{
        
        Logger.initialLogger();
        m_Logger = new Logger();
        
        m_szIP  = szIP;
        m_nPort = nPort;
        
        serverSocket=new ServerSocket(m_nPort);
        //Runtime的availableProcessor()方法返回当前系统的CPU数目.
        executorService=Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors()*POOL_SIZE/2);
        m_Logger.info("IndexSeeker","IndexSeeker","服务器启动");
        m_Logger.info(System.getProperty("file.encoding"));
    }
    
    public void run() {
        while(true){
            Socket socket=null;
            try {
                //接收客户连接,只要客户进行了连接,就会触发accept();从而建立连接
                socket=serverSocket.accept();
                executorService.execute( new searchHandler(socket) );
                
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    
    public void shutDown() {
        
    }
    
    
    public static void main( String[] args ) {
        IndexSeeker seeker=null;
        try {
            seeker = new IndexSeeker( "127.0.0.1", 10001 );
            Thread thread = new Thread( seeker);
            thread.start();            
        }
        catch( IOException e ) {
            System.out.println( "Cannot open server port!");
            System.exit(-1);
        }
    }
} class searchHandler implements Runnable {
    protected static String FIELD_TITLE = "Description";
    protected static String FIELD_ID = "JobID";
    protected static String INDEX_STORE_PATH = "E:\\Baizeju\\Index";

    private Socket socket;
    public searchHandler(Socket socket){
        this.socket=socket;
    }
    private PrintWriter getWriter(Socket socket) throws IOException{
        OutputStream socketOut=socket.getOutputStream();
        return new PrintWriter(socketOut,true);
    }
    private BufferedReader getReader(Socket socket) throws IOException{
        InputStream socketIn=socket.getInputStream();
        return new BufferedReader(new InputStreamReader(socketIn));
    }
    public String echo(String msg){
        return "echo:"+msg;
    }
    public void run(){
        Logger logger = new Logger();
        try {
            System.out.println("New connection accepted "+socket.getInetAddress()+":"+socket.getPort());
            BufferedReader br=getReader(socket);
            PrintWriter pw=getWriter(socket);
            String msg=null;
           
            while((msg=br.readLine())!=null){
                if( !msg.trim().equalsIgnoreCase("") ) {
                    ArrayList<String> results = doSearch( new String(msg.getBytes(),"GBK" ) );
                    
                    for( int nIndex=0; nIndex<results.size();nIndex++) {
                        pw.print(new String(results.get(nIndex).getBytes("GBK")));
                        pw.print("<br>");
                    }
                    pw.println();
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            try {
                if(socket!=null){
                    socket.close();
                }
                System.out.println( "Connection closed!");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    
    public ArrayList<String> doSearch( String szQuery ) {
        ArrayList<String> results = new ArrayList<String>();
        
        try {
            //Directory ramDir = new RAMDirectory(INDEX_STORE_PATH);

            // 将庖丁封装成符合Lucene要求的Analyzer规范
            Analyzer analyzer = new PaodingAnalyzer();

            IndexReader reader =  IndexReader.open( INDEX_STORE_PATH );            QueryParser parser = new QueryParser(FIELD_TITLE, analyzer);
            Query query = parser.parse(szQuery);
            Searcher searcher = new IndexSearcher(INDEX_STORE_PATH);
            query = query.rewrite(reader);
            System.out.println("Searching for: " + new String( query.toString().getBytes("GBK")));
            Hits hits = searcher.search(query);            int nItemNumber = Math.min( 20, hits.length());
            for (int i = 0; i < nItemNumber; i++) {
                String szText = hits.doc(i).get(FIELD_TITLE);
                QueryScorer scorer = new QueryScorer( query );
                Highlighter highlighter = new Highlighter( new SimpleHTMLFormatter("<b><I>", "</I></b>"),scorer );                TokenStream tokenStream = new PaodingAnalyzer().tokenStream( FIELD_TITLE, new StringReader(szText));
                
                results.add(highlighter.getBestFragment(tokenStream, szText));
            }
            //reader.close();
        }
        catch( CorruptIndexException e ) {
            e.printStackTrace();
        }
        catch( IOException e ) {
            e.printStackTrace();
        }
        catch( ParseException e ) {
            e.printStackTrace();
        }
        catch( Exception e ) {
            e.printStackTrace();
        }
        return results;
    }
}

Answer 4

另外at testsocket.Ctosthread.run(newmain.java:125) 是哪一行？
应该是刚刚进run的前面吧，String lineStr = in.readLine(); 
在这一行就出Exception了，当然走不到后面初始化serversend ssd=new serversend(ts,newmain.lr); 那里，也就没有给客户端发信息了。

Answer 5

那是什么原因让这个lineStr=in.readline()出错呀???就我的代码而言?

Answer 6

哈哈，楼主的程序错误真隐蔽啊。帮你调了一下才找到。首先看看这篇文章：
http://www.baizeju.com/html/Java/200807/30-159.html
了解一下Java Socket编程各种Exception的含义。
你遇到的异常说明如下：
第4个异常是java.net.SocketException: （Connection reset或者Connect reset by peer:Socket write error）。该异常在客户端和服务器端均有可能发生，引起该异常的原因有两个，第一个就是如果一端的Socket被关闭（或主动关闭或者因为异常退出而引起的关闭），另一端仍发送数据，发送的第一个数据包引发该异常(Connect reset by peer)。另一个是一端退出，但退出时并未关闭该连接，另一端如果在从连接中读数据则抛出该异常（Connection reset）。简单的说就是在连接断开后的读和写操作引起的。看来问题出在客户端，客户端退出，但是退出前没有关闭链接，造成这个异常。下面来看看客户端为什么会退出。
你关闭链接用的是link_server.close(); 如果没有走到这一句，就不会关闭。你下面的
catch(Exception e)
        {
           
        } 
看上去就很可疑。在里面增加一句：e.printStackTrace();看看，再跑一次，狐狸尾巴就出来了。客户端报错：
java.lang.NullPointerException
        at TestCode.SocketClient.run(SocketClient.java:65)
        at TestCode.SocketClient.main(SocketClient.java:104)
BUILD SUCCESSFUL (total time: 1 second)
到65行去看看：
 link_bwout.write(send_info);
link_bwout是null。找一找，link_bwout好像没有初始化啊。

Answer 7

我重新写了代码,接收和发送现在都能成了,但是新的问题是:在我构造的介面中,只有第一次按下按钮,能正常收发,第二次按下按钮后,就报错了,请指教server端
package socketcs;import java.awt.BorderLayout;
import java.io.*;
import java.net.*;
import java.awt.event.*;
import java.lang.*;
import javax.swing.*;
public class serversk extends JFrame
{
    JLabel title=new JLabel("服务器监视登录");
    javax.swing.JScrollPane jsp;
    public static javax.swing.JTextArea jta1;
    public serversk()
    {
        this.setLayout(new BorderLayout());
        jsp=new JScrollPane();
        jta1=new JTextArea();
        jta1.setSize(640,480);
        jsp.setViewportView(jta1);
        jta1.setVisible(true);
        this.getContentPane().add(title,BorderLayout.NORTH);
        title.setVisible(true);
        this.getContentPane().add(jsp,BorderLayout.CENTER);
    }
    
    
    public static void main(String[] args)
    {
        serversk sk=new serversk();
        
        sk.setSize(800,600);
        sk.setVisible(true);
        try{
            ServerSocket ss=new ServerSocket(9516);
            Socket s=ss.accept();
            inout ios=new inout(s);
            new Thread(ios).start();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        sk.setDefaultCloseOperation(sk.EXIT_ON_CLOSE);
    }
}class inout implements Runnable
{
    Socket iosocket=null;
    java.io.BufferedReader br=null;
    java.io.BufferedWriter bw=null;
    public inout(Socket ss)
    {
        this.iosocket=ss;
    }    public void run() {
        try
        {
            bw=new BufferedWriter(new java.io.OutputStreamWriter(iosocket.getOutputStream()));
            br=new BufferedReader(new java.io.InputStreamReader(iosocket.getInputStream()));
            if(true)
            {
                String gets=br.readLine();
                serversk.jta1.append(gets);
            }
            bw.write("收到");
            bw.flush();
            bw.close();
            br.close();
            this.iosocket.close();
        }
        catch(Exception ex)
        {
            
        }
    }
}client端
package h;
import java.io.*;
import java.net.*;
import javax.swing.*;public class cinout extends javax.swing.JFrame {
    
    java.net.Socket c=new Socket();
    java.net.SocketAddress link_sa=null;
    BufferedWriter cout=null;
    BufferedReader cin=null;
    String link_sports="9516";
    String link_server_ip=null;
    boolean flag=false;
    public cinout() {
        initComponents();
        
    }
                       
    private void initComponents() {
//略
    }// </editor-fold>                            private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//此处第一次按下收发正常,再按即报错        
         try{
             if(cjtf1.getText().length()>0)
             {
                     link_server_ip=java.net.InetAddress.getByName("www.abc.net").getHostAddress().toString();
                     link_sa=new java.net.InetSocketAddress(link_server_ip,java.lang.Integer.parseInt(link_sports));
                     c.connect(link_sa);
                     flag=true;                     cin=new BufferedReader(new java.io.InputStreamReader(c.getInputStream()));
                     cout=new BufferedWriter(new java.io.OutputStreamWriter(c.getOutputStream()));
                     cout.write(cjtf1.getText()+"\n");
                     cout.flush();
                     if(true)
                     {
                         String appstr=cin.readLine();
                         cjta1.append(appstr);
                     }
                     cout.close();
                     cin.close();
                     c.close();
             }
             else
             {
                 cjtf1.setText("请输入信息");
             }
             
         }
         catch(Exception e)
         {
             e.printStackTrace();
         }
         
    }                                        
    
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new cinout().setVisible(true);
            }
        });
    }
    
    // 变量声明 - 不进行修改                     
    private javax.swing.JTextArea cjta1;
    private javax.swing.JTextField cjtf1;
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JScrollPane jScrollPane1;
    // 变量声明结束                   
    
}

Answer 8

-----------------------客户端package test2;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;public class Client {
private Socket socket; private BufferedReader in; private PrintWriter out; public Client() {
try {
socket = new Socket("localhost", 8020);
in = new BufferedReader(new InputStreamReader(socket
.getInputStream()));
out = new PrintWriter(socket.getOutputStream());
System.out.println("请输入你要说的话");
BufferedReader line = new BufferedReader(new InputStreamReader(
System.in));
String message = line.readLine();
System.out.println(message);
out.write(message);
out.flush();
line.close();
in.close();
out.close();
socket.close(); } catch (UnknownHostException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
} catch (IOException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
}
} public static void main(String[] args) {
// TODO 自动生成方法存根
new Client();
}}----------------------------服务器端package test2;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;public class Service { private ServerSocket ss; private Socket socket; private PrintWriter out; private BufferedReader in; public Service() {
try {
ss = new ServerSocket(8020);
while (true) {
socket = ss.accept();
in = new BufferedReader(new InputStreamReader(socket
.getInputStream()));
out = new PrintWriter(socket.getOutputStream());
String line = in.readLine();
System.out.println("你输入的是" + line);
out.close();
in.close();
socket.close();
// ss.close();
} } catch (IOException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
} } public static void main(String[] args) {
// TODO 自动生成方法存根
new Service();
}}