程序提示java.lang.NullPointerException,请问何解。
package df;
import java.net.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
import java.util.concurrent.*;
public class df extends JFrame implements ActionListener
{
JPanel pSaler;
JPanel pBuyer;
JLabel lbBuyer,lbSaler;
JTextField txtSaler;
JTextArea txtBuyer;
JScrollPane jsp;
JButton btnStart;
private ExecutorService executorService;//线程池
private final int POOL_SIZE=10;//单个CPU线程池大小
ServerSocket serverSocket;
Socket sock;
DataOutputStream out;
DataInputStream in;
public df()
{
try
{
serverSocket=new ServerSocket(8888);
JOptionPane.showMessageDialog(null, "服务器启动成功");
}
catch(IOException e)
{
JOptionPane.showMessageDialog(null, "服务器启动失败");
}
createUI();
}
public void service()
{
while(true)
{
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
sock=serverSocket.accept();
executorService.execute(new Handler(sock,this));
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
public static void main(String args[])
{
new df().service();
}
}Hander代码:package df;
import java.io.*;
import java.net.Socket;class Handler implements Runnable{
private Socket sock;
DataOutputStream out;
DataInputStream in;
df fp;
public Handler(Socket sock,df fp){
this.sock=sock;
}
public void run()
{
try
{
System.out.println("New connection accepted "+sock.getInetAddress()+":"+sock.getPort());
out=new DataOutputStream(sock.getOutputStream());
in=new DataInputStream(sock.getInputStream());
out.writeUTF("连接服务器成功");
}
catch(Exception e)
{
e.printStackTrace();
}
while(true)
{
try
{
String msg;
msg=fp.in.readUTF();
int port=Integer.parseInt(msg);
if(port<8000)
{
fp.txtBuyer.append("买家:"+msg+"进来了\n");
}
else
{
fp.txtSaler.setText(""+msg);
}
}
catch(Exception ee)
{break;}
}
}
}
import java.net.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
import java.util.concurrent.*;
public class df extends JFrame implements ActionListener
{
JPanel pSaler;
JPanel pBuyer;
JLabel lbBuyer,lbSaler;
JTextField txtSaler;
JTextArea txtBuyer;
JScrollPane jsp;
JButton btnStart;
private ExecutorService executorService;//线程池
private final int POOL_SIZE=10;//单个CPU线程池大小
ServerSocket serverSocket;
Socket sock;
DataOutputStream out;
DataInputStream in;public df()
{
try
{
serverSocket=new ServerSocket(8888);
JOptionPane.showMessageDialog(null, "服务器启动成功");
}
catch(IOException e)
{
JOptionPane.showMessageDialog(null, "服务器启动失败");
}
createUI();
}
public void service()
{
while(true)
{
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
sock=serverSocket.accept();
executorService.execute(new Handler(sock,this));
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
public static void main(String args[])
{
new df().service();
}
}Hander代码:package df;
import java.io.*;
import java.net.Socket;class Handler implements Runnable{
private Socket sock;
DataOutputStream out;
DataInputStream in;
df fp;
public Handler(Socket sock,df fp){
this.sock=sock;
}
public void run()
{
try
{
System.out.println("New connection accepted "+sock.getInetAddress()+":"+sock.getPort());
out=new DataOutputStream(sock.getOutputStream());
in=new DataInputStream(sock.getInputStream());
out.writeUTF("连接服务器成功");
}
catch(Exception e)
{
e.printStackTrace();
}
while(true)
{
try
{
String msg;
msg=fp.in.readUTF();
int port=Integer.parseInt(msg);
if(port <8000)
{
fp.txtBuyer.append("买家:"+msg+"进来了\n");
}
else
{
fp.txtSaler.setText(""+msg);
}
}
catch(Exception ee)
{break;}
}
}
}
http://blog.csdn.net/hzhxxx/archive/2009/12/09/4970196.aspx下列描述了JNSP(java network service platform)服务的部署和功能,如有不明白之处,自己查看源代码,我无力和没有太多时间回答太多的问题.
源代码一起提供,可以随意修改,发布,并商业化,但请保留作者的信息.为了技术的进步,请注意共享成就.目前已经发布于:http://download.csdn.net/source/1885332;http://hzhxxx.download.csdn.net/
如果查看后有技术问题探讨和建议的,欢迎致电致信联系.系统架构设计和实现有如下特点:
A. 采用 Accept-Connect 通讯模型,能统一管理系统中使用的所有 Socket 资源;
B. 系统支持通信和协议分离的实现原则,支持自定义协议解析模块;通信负责数据收发,协议负责数据鉴别,两者配合实现通信和协议的和谐工作;
C. 灵活支持业务处理功能重定义,分级支持慢业务和快业务的不同业务处理线程;
D. 丰富灵活的配置参数,能满足高扩展性;
E. 配合业务处理和通信模型,能异步的管理所有的交互步骤;
F. 分布式服务设计和部署,实现动态(热拔插)的增加和较少业务服务器,减少乃至拒绝单点服务;