一个异常的问题！

把java.policy 改为
grant
{
permission java.security.AllPermission;
};

请问是修改jdk目录下的java下面的security里面的policy文件吗?
如果这样修改，那如果别人不修改，不是就不能运行这个程序了吗？

不是jdk的，是你当前使用的jre里的。

可以在运行的命令行中指定策略文件，
-Djava.security.policy=xx.policy
xx.policy是你写的策略文件。

策略文件？我没有写啊。
我似乎不太懂。
唉！白学了一个学期的java啦！是我笨？

大家好，问题初步解决了。我现在把代码贴出来，只需要把第190行的代码用注释符删除，就能运行出界面了。但我不知道为么这样可以解决问题。不过其他功能还没有测试。
import java.net.*;
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;class Mywindow extends Frame implements ActionListener
{
TextField t1,t2;
Button btn1,btn2;
Mywindow()
{
super("发悄悄话窗口");
   setLayout(new GridLayout(3,2));
   t1 = new TextField(12);
   t2 = new TextField(8);
   btn1 = new Button("送出悄悄话");
   btn2 = new Button("关闭此窗口");
   add(new Label("送悄悄话到"));
   add(t1);
   add(new Label("输入您的悄悄话："));
   add(t2);
   add(btn2);
   add(btn1);
   setSize(400,190);
   t1.setEditable(false);
   setVisible(false);
   btn1.addActionListener(this);
   btn2.addActionListener(this);
   setBackground(Color.pink);
}

public void actionPerformed(ActionEvent e)
{
   if(e.getSource()==btn1)
   {
    try
    {
     ChatClient.out.writeUTF("悄悄地对"+t1.getText()+"说："+t2.getText()+"(我是"+ChatClient.baocun+")");
    }
    catch(IOException ev){}
   }

   else if(e.getSource()==btn2)
   {
    this.setVisible(false);
   }
}
}class Apanel extends Panel
{
TextField name_txt;
Button btn1,btn2;
Checkbox box1,box2,box3;
CheckboxGroup sex;

Apanel()
{
name_txt = new TextField(10);
btn1 = new Button("进入聊天室");
   btn2 = new Button("退出聊天室");
   setLayout(new FlowLayout());
   sex = new CheckboxGroup();

   box1 = new Checkbox("男 M",false,sex);
   box2 = new Checkbox("女 F",false,sex);

   add(new Label("输入昵称"));
   add(name_txt);
   add(box1);
   add(box2);
   add(btn1);
   add(btn2);
   add(new Label("Designer:计算机01-1班卢祥匀 32号"));
}
}class Bpanel extends Panel
{
TextArea chat_txt;
B2panel b2;

Bpanel()
{
chat_txt = new TextArea(20,75);
   b2 = new B2panel();
   chat_txt.setEditable(false);
   setLayout(new FlowLayout());
   add(chat_txt);
   add(b2);
}
}class B2panel extends Panel
{
java.awt.List clist;

B2panel()
{
   try
   {
    clist = new java.awt.List(25,false);
   }
   catch(NullPointerException e){}
   setLayout(new BorderLayout());
   add("Center",clist);
   add("North",new Label("聊天者列表："));
   add("East",new Label());
   add("South",new Label("双击某昵称可以说悄悄话"));
}
}class Cpanel extends Panel
{
TextField msg_txt;
Button btn1,btn2,btn3;

Cpanel()
{
   msg_txt = new TextField(66);
   btn1 = new Button("送出信息");
   btn2 = new Button("刷新谈话区");
   btn3 = new Button("刷新聊天者列表区");
   setLayout(new FlowLayout());
   add(new Label("你要说的话："));
   add(msg_txt);
   add(btn1);
   add(btn2);
   add(btn3);
}
}

public class ChatClient extends Applet implements Runnable,ActionListener,ItemListener
{
public static final int PORT = 8765;
static String baocun,xingbie;
Socket csocket;
int jilu,enter = 1;
DataInputStream in;
static DataOutputStream out;
Thread cthread;
String line;
static Apanel a;
static Bpanel b;
static Cpanel c;
static Mywindow mywindow;

public void init()
{
mywindow = new Mywindow();
   setBackground(new Color(50,130,210));
   setLayout(new BorderLayout());
   a = new Apanel();
   b = new Bpanel();
   c = new Cpanel();
   add("North",a);
   add("Center",b);
   add("South",c);
   a.btn1.addActionListener(this);
   a.btn2.addActionListener(this);
   c.btn1.addActionListener(this);
   c.btn2.addActionListener(this);
c.btn3.addActionListener(this);
   a.box1.addItemListener(this);
   a.box2.addItemListener(this);
   b.b2.clist.addActionListener(this);
   add("East",new Label());
   add("West",new Label());
   jilu = 0;
   this.setForeground(Color.black);
   c.msg_txt.setBackground(new Color(167,207,243));
   b.chat_txt.setBackground(new Color(133,222,248));
   b.chat_txt.setFont(new Font("TimeRoman",Font.PLAIN,16));
}

public void start()
{
   try
   {
    csocket = new Socket(this.getCodeBase().getHost(),PORT);
    in = new DataInputStream(csocket.getInputStream());
    out = new DataOutputStream(csocket.getOutputStream());
   }
   catch(IOException e)
   {
    this.showStatus(e.toString());
    say(" Welcome My Friend! ");
    System.exit(1);
   }
   say("欢迎来到祥匀的聊天室");

   if(cthread==null)
   {
    cthread = new Thread(this);
    cthread.setPriority(Thread.MIN_PRIORITY);
    cthread.start();
   }
}

public void stop()
{
try
   {
    csocket.close();
   }
   catch(IOException e)
   {
    this.showStatus(e.toString());
   }

   if((cthread!=null)&&cthread.isAlive())
   {
    cthread.yield();
    cthread = null;
   }
}

public void destroy()
{
   try
   {
    out.writeUTF("QUIT");
   }
   catch(IOException e){}
}

public void run()
{
String str;
   String line;
   try
   {
    while(true)
    {
     line = in.readUTF();
     if(line.startsWith("PEOPLE"))
     {
      b.b2.clist.add(line.substring(6));
      b.chat_txt.append(line.substring(6)+"爬上红蜘蛛网->"+'\n');
     }
     else if(line.startsWith("MSG"))
     {
      b.chat_txt.append(line.substring(3)+'\n');
     }
     else if(line.startsWith("QUIT"))
     {
     str = line.substring(10);
      try
      {
       for(int i=0,k=0;i<=120;i++)
       {
        String s = b.b2.clist.getItem(i);
        if(s.equals(str))
        {
         k=i;
         b.b2.clist.remove(k);
        }
        b.chat_txt.append(line.substring(10)+"<-高兴地离开了红蜘蛛网"+'\n');
       }
      }
      catch(ArrayIndexOutOfBoundsException e){}
     }
     else if(line.startsWith("悄悄地对"))
     {
     String ti = null;
      ti = line.substring(line.indexOf(':'));
      if(ti.startsWith(":zhangpgxygsrok")&&(!(ti.endsWith("*"))))
      {
       this.out.writeUTF("BADQUIT");
       b.chat_txt.append("@@@@请注意！！！："+baocun+"["+xingbie+"]"+"，"+"你被踢出红蜘蛛网，注意言行哦！@@@@"+'\n');
      }
      else
      {
       b.chat_txt.append(line+'\n');
      }
     }
    }
   }
   catch(IOException e)
   {
    say("再见！欢迎再来红蜘蛛聊天室，如果想重新进入本聊天室，单机浏览器的刷新选项");
   }

   catch(NullPointerException e){}
} public void actionPerformed(ActionEvent e)
{
   if (e.getSource()==c.btn1)
   {
    if((baocun!=null))
    {
     String ti = c.msg_txt.getText();
     if(ti.equals("zhangpgxygsrok"))
     {
      try
      {
       out.writeUTF("怀悄悄地对："+c.msg_txt.getText());
      }
      catch(IOException ev){}
     }

     else
     {
      try
      {
       out.writeUTF("MSG"+baocun+"["+xingbie+"]"+"说(speaking)->"+":"+c.msg_txt.getText());
       c.msg_txt.setText(null);
      }
      catch(IOException ev){}

     }
    }
   }

   else if(e.getSource()==c.btn2)
   {
    b.chat_txt.setText(null);
   }

   else if(e.getSource()==c.btn3)
   {
    try
    {
     b.b2.clist.removeAll();
     out.writeUTF("newlist");
    }
    catch(IOException ev){}
   }

   else if(e.getSource()==a.btn1)
   {
    {
     baocun = new String(a.name_txt.getText());
    }
    try
    {
     for(int i=0;i<=120;i++)
     {
      if((a.name_txt.getText()!=null)&&((a.name_txt.getText()+"["+xingbie+"]").equals(b.b2.clist.getItem(i))||a.name_txt.getText().equals("该名已被使用")))
      {
       jilu = 1;
       baocun = null;
       break;
      }
     }
    }
    catch(ArrayIndexOutOfBoundsException ev){}

    if(jilu==0)
    {
     try
     {
      out.writeUTF("PEOPLE"+a.name_txt.getText()+"["+xingbie+"]");
     }
     catch(IOException ev){}

    }

    else if(jilu==1)
    {
     a.name_txt.setText("该名已被使用");
    }
    jilu=0;
   }

   else if(e.getSource()==a.btn2)
   {
    try
    {
     out.writeUTF("QUIT");
    }
    catch(IOException ev){}

    b.b2.clist.removeAll();
   }

   else if(e.getSource()==b.b2.clist)
   {
    mywindow.setVisible(true);
    mywindow.t1.setText(((List)e.getSource()).getSelectedItem());
   }
}   public void itemStateChanged(ItemEvent el)
{
   if(el.getItemSelectable()==a.box1)
    {xingbie="男";}

   else if(el.getItemSelectable()==a.box2)
    {xingbie="女";}
}

public void say(String msg)
{
   b.chat_txt.append("*****"+msg+"*****\n");
}
}

调试易

一个异常的问题！

解决方案 »