您好我正在尝试获取有关连接到同一台机器中的mutltythreaded服务器进程的套接字客户端的一些数据。服务器线程被正确触发，客户端IP被检索确定，但我似乎无法通过连接发送字符串。 客户
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package solverapplet;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.*;
/**
*
* @author me
*/
public class Solverapplet {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
Socket s;
try {
s = new Socket("IP", 4445);
System.out.println(s.getPort());
//DataInputStream in = new DataInputStream (s.getInputStream());
BufferedWriter out = new BufferedWriter(
new OutputStreamWriter(s.getOutputStream()));
out.write("gamma");
out.newLine();
out.flush();
} catch (UnknownHostException ex) {
Logger.getLogger(Solverapplet.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(Solverapplet.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
服务器线程
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package serversideserver;
import java.io.*;
import java.net.*;
import java.security.*;
import java.util.List;
import java.sql.*;
import com.google.gson.Gson;
class doComms implements Runnable {
private Socket server;
private String line,input,ip;
doComms(Socket server, String ip) {
this.server=server;
this.ip=ip;
}
public void run () {
input="";
try {
// Get input from the client
BufferedReader in = new BufferedReader(
new InputStreamReader(server.getInputStream()));
PrintStream out = new PrintStream(server.getOutputStream());
Connection conn = null;
try
{
String userName = "root";
String password = "";
String url = "jdbc:mysql://localhost/test";
Class.forName ("com.mysql.jdbc.Driver").newInstance ();
conn = DriverManager.getConnection (url, userName, password);
System.out.println ("Database connection established");
// create the java statement
Statement st = conn.createStatement();
// ResultSet rs;
while((line = in.readLine()) != null && !line.equals(".")) {
// Now do the magic.
//Data data = new Gson().fromJson(line, Data.class);
System.out.println("LINE: " + line);
input=line;
st.executeUpdate("UPDATE `solvers` SET `online`='1',`ip`='"+ server.getInetAddress().toString().substring(1) +"' WHERE `user`='"+ line +"'");
// input= data.getcmd();
out.println("{\"captcha\":1,\"text\":\"abc\",\"is_correct\":\"true\"}");
}
}
catch (Exception e)
{
System.out.println (e.toString());
}
// Now write to the client
System.out.println("UPDATE `solvers` SET `online`='1',`ip`='"+ server.getInetAddress() +"' WHERE `user`='"+ input +"'");
//out.println("Overall message is:" + input);
server.close();
} catch (IOException ioe) {
System.out.println("IOException on socket listen: " + ioe);
ioe.printStackTrace();
}
}
}
发送的行是空的。 建立连接
package serversideserver;
import java.io.*;
import java.net.*;
import java.security.*;
import java.sql.*;
/**
* Title: Sample Server
* Description: This utility will accept input from a socket, posting back to the socket before closing the link.
* It is intended as a template for coders to base servers on. Please report bugs to brad at kieser.net
* Copyright: Copyright (c) 2002
* Company: Kieser.net
* @author B. Kieser
* @version 1.0
*/
public class Serversideserver {
private static int port=4445,portsolver=4445, maxConnections=0;
// Listen for incoming connections and handle them
public static void main(String[] args) {
int i=0;
try{
ServerSocket listener = new ServerSocket(port);
Socket server;
long counter=0;
int counter1=0;
int id=0;
String ip="uninit";
while((i++ < maxConnections) || (maxConnections == 0)){
server = listener.accept();
counter++;
doComms conn_c= new doComms(server,ip);
Thread t = new Thread(conn_c);
t.start();
//System.out.println("counter "+ (counter % id) );
}
} catch (IOException ioe) {
System.out.println("IOException on socket listen: " + ioe);
ioe.printStackTrace();
}
}
}
答案 0 :(得分：1)
我看起来你有一些时间问题。以下是具有正确时序的代码。请注意，我删除了手头问题所不需要的代码。
客户端：在客户端看起来，您正在写入套接字并立即终止应用程序（导致连接关闭）。 doComms类正在写回客户端，所以我添加了代码来读取响应。但是，如果您没有期待响应，那么您仍然希望读取一个字节。这将允许您确保获得EOF而不是某些数据，并且它会阻止当前线程并使连接保持活动状态。
package solverapplet;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.*;
/**
*
* @author you
*/
public class Solverapplet {
/**
* @param args the command line arguments
* @throws IOException
*/
public static void main(String[] args) throws IOException {
Socket s = null;
try {
// make connection
s = new Socket("localhost", 4445);
// define streams
BufferedWriter out = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
// write data
out.write("gamma");
out.newLine();
out.flush();
// read response
String returnData = in.readLine();
System.out.println(returnData);
} catch (UnknownHostException ex) {
Logger.getLogger(Solverapplet.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(Solverapplet.class.getName()).log(Level.SEVERE, null, ex);
} finally {
// close connection
s.close();
}
}
}
服务器：我已将服务器更改为在任何给定时间允许最大连接数，而不是在建立最大连接数后关闭。另外，请注意我的线程不是守护进程。如果要为X号客户端提供服务然后关闭，则需要一种机制来允许线程在关闭ServerSocket之前继续执行
package serversideserver;
import java.io.*;
import java.net.*;
/**
* Title: Sample Server
* Description: This utility will accept input from a socket, posting back to the socket before closing the link.
* It is intended as a template for coders to base servers on. Please report bugs to brad at kieser.net
* Copyright: Copyright (c) 2002
* Company: Kieser.net
* @author B. Kieser
* @version 1.0
*/
public class Serversideserver {
private static int port =4445;
private static int maxConnections =10;
private static int connections = 0;
synchronized static void connectionClosed() {
connections--;
Serversideserver.class.notify();
}
/**
* The blocking mechanism to only allow <code>maxConnections<code>
* @throws InterruptedException
* thrown if blocking thread is interupted
*/
private synchronized static void nextConnection() throws InterruptedException {
while(connections>=maxConnections) {
Serversideserver.class.wait();
}
}
public static void main(String[] args) throws InterruptedException {
try{
// server socket
ServerSocket listener = new ServerSocket(port);
// socket
Socket socket;
// Keep the server alive
while(true){
// Blocks if we have reached the max
nextConnection();
// Accept connection to client
socket = listener.accept();
// define request service
doComms conn_c= new doComms(socket,socket.getInetAddress().getCanonicalHostName());
Thread t = new Thread(conn_c);
t.setDaemon(false);
// run request service
t.start();
}
} catch (IOException ioe) {
System.out.println("IOException on socket listen: " + ioe);
ioe.printStackTrace();
}
}
}
doComms：这个类没有太大变化......我只是稍微清理了一下并删除了不必要的代码行。
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package serversideserver;
import java.io.*;
import java.net.*;
class doComms implements Runnable {
private Socket socket;
private String ip;
doComms(Socket socket, String ip) {
this.socket = socket;
this.ip = ip;
}
public void run () {
try {
// Define input/output
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintStream out = new PrintStream(socket.getOutputStream());
// Process requests until the EOF is found
String line;
while((line = in.readLine()) != null && !line.equals(".")) {
// print input
System.out.println("LINE: " + line);
// print process line
System.out.println("UPDATE `solvers` SET `online`='1',`ip`='"+ ip +"' WHERE `user`='"+ line +"'");
// write response
out.println("{\"captcha\":1,\"text\":\"abc\",\"is_correct\":\"true\"}");
}
socket.close();
} catch (IOException ioe) {
System.out.println("IOException on socket listen: " + ioe);
ioe.printStackTrace();
} finally {
Serversideserver.connectionClosed();
}
}
}
希望这会有所帮助：）
答案 1 :(得分：0)
您的问题非常模糊，但如果您想知道为什么服务器无法回复您的客户端，那是因为客户端永远不会从套接字读取。