通过实例可以更好的了解java

25-例子1
import javax.swing.*;import java.awt.*;import java.awt.event.*;
public class Example25_1
{ public static void main(String args[])
  {JButton button=new JButton("轻组件按钮");
   JTextArea text=new JTextArea("轻组件",20,20);
    JFrame  jframe=new JFrame("根窗体");
    jframe.setSize(200,300);jframe.setBackground(Color.blue);
    jframe.setVisible(true);jframe.pack();
    jframe.addWindowListener(new WindowAdapter()
         {public void windowClosing(WindowEvent e)
            {System.exit(0);} });
       Container contentpane=jframe.getContentPane();//获得内容面板。
    contentpane.add(button,BorderLayout.SOUTH); //向内容面板加入组件。
contentpane.add(text,BorderLayout.CENTER);
jframe.pack();//用紧凑方式显示窗口，该语句最好应在所有添加组件的语句之后。
  } 
}



25-例子2
import javax.swing.*;import java.awt.*;import java.awt.event.*;
class Mywindow extends JFrame
{ JButton button;JTextArea text;
   Mywindow()
   {setSize(200,400);setVisible(true);
     Container con=getContentPane(); con.setLayout(new FlowLayout());
     button=new JButton("ok");text=new JTextArea(10,20);
     con.add(button);con.add(text);pack();
     addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
      {System.exit(0);}});
   }
}
public class Example25_2
{ public static void main(String args[])
  { Mywindow win=new Mywindow();win.pack();
  }
}



25-例子3
import javax.swing.*;import java.awt.BorderLayout;
public class Example25_3 extends JApplet
{ JButton  button;   JTextArea  text;
   public void init()
{ button=new JButton("确定");text=new JTextArea();
 getContentPane().add(text,BorderLayout.CENTER); //小程序容器得到内容面板。
 getContentPane().add(button,BorderLayout.WEST);//并向内容面板中添加组件。
 } 
}



25-例子4
import javax.swing.*;import java.awt.*;import java.awt.event.*;
class Dwindow extends JFrame //建立根窗体用的类。
{ JButton button1,button2;
  Dwindow(String s)
  { super(s);
    Container con=getContentPane();  
    button1=new JButton("打开"); button2=new JButton("关闭");
    con.add(button1);con.add(button2);pack();
    setVisible(true);
    addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
        {System.exit(0);}});
  }
}
class Mydialog extends JDialog //建立对话框类。
{ JButton  button1,button2; 
  Mydialog(JFrame F,String s)   //构造方法。
  { super(F,s);
  button1=new JButton("open");     button2=new JButton("close"); 
  setSize(90,90);setVisible(true);setModal(false); 
  Container con=getContentPane();con.setLayout(new FlowLayout());
    con.add(button1);con.add(button2);
    addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
        {System.exit(0);}});
  }
}
public class Example25_4 extends JApplet
{ Dwindow window;  Mydialog dialog;  JButton button;
 public void init()
 { window=new Dwindow("带对话框窗口");//创建窗口。
   dialog=new Mydialog(window,"我是对话框");  //创建依赖于窗口window的对话框。
   button=new JButton("ok");  getContentPane().add(button);
 }
}



25-例子5
import javax.swing.*;import java.awt.*;import java.awt.event.*;
class Myframe extends JFrame implements ActionListener
{ JButton button;JTextArea text;
   Myframe()
   { setSize(200,400);setVisible(true);
     Container con=getContentPane(); 
     con.setLayout(new FlowLayout());
     button=new JButton("ok");text=new JTextArea(10,20);
     con.add(button);con.add(text);
     button.addActionListener(this);
     addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
        {System.exit(0);}});
   }
 public void actionPerformed(ActionEvent e)
  { if(e.getSource()==button)
    text.setText("i am a boy,and you?");
  }
}
public class Example25_5
{ public static void main(String args[])
  { Myframe fr=new Myframe();fr.pack();
  }
}



25-例子6
 import javax.swing.*; import java.awt.*;
class Mycanvas extends JPanel
{ public void paintComponent(Graphics g)
  { super.paintComponent(g);
    g.setColor(Color.red);  g.drawString("a Jpanel used as canvas",50,50);
  }
}
public class Example25_6 extends JApplet
{ Mycanvas canvas; JPanel panel;JButton button;
  public void init()
  { canvas=new Mycanvas();panel=new JPanel();button=new JButton("ok");
    panel.add(button); Container con=getContentPane();
    con.add(panel,BorderLayout.NORTH); con.add(canvas,BorderLayout.CENTER); 
  }
}



25-例子7
import javax.swing.*;import java.awt.*;import java.awt.event.*;
class Mywindow extends JFrame
{ JButton button;JTextArea text;JScrollPane scroll;
   Mywindow()
   { setSize(200,400);setVisible(true);
   Container con=getContentPane(); 
   button=new JButton("ok");text=new JTextArea(10,20);
   scroll=new JScrollPane(text);
   con.add(button,BorderLayout.SOUTH);con.add(scroll,BorderLayout.CENTER);
   addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
        {System.exit(0);}});
   }
}
public class Example25_7
{ public static void main(String args[])
  { Mywindow win=new Mywindow();win.pack();
  }
}



25-例子8
import javax.swing.*;import java.awt.*;import java.awt.event.*;
class Mywindow extends JFrame
{ JButton button1,button2;JTextArea text;JSplitPane split_one,split_two;
   Mywindow()
   {setSize(200,400);setVisible(true); Container con=getContentPane(); 
    button1=new JButton("ok"); button2=new JButton("No");
    text=new JTextArea("I love you,java",10,20);
    split_one=new JSplitPane(JSplitPane.VERTICAL_SPLIT,button1,button2);
    split_two=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true,split_one,text);
    con.add(split_two,BorderLayout.CENTER);
    addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
        {System.exit(0);}});
   }
}
public class Example25_8
{ public static void main(String args[])
  { Mywindow win=new Mywindow();win.pack();
  }
}



25-例子9
import javax.swing.*;import java.awt.*;import java.awt.event.*;
class Mywindow extends JFrame
{ JButton button1,button2;
  JInternalFrame interframe_1,interframe_2;
   Mywindow()
   {setSize(200,200);setVisible(true); Container con=getContentPane();
  con.setLayout(new GridLayout(1,2)); 
  button1=new JButton("Boy"); button2=new JButton("Girl");
  interframe_1=new JInternalFrame("内窗体1",true,true,true,true);
  interframe_1.setSize(100,100);
  interframe_1.getContentPane().add(button1);
  JDesktopPane  desk1=new JDesktopPane();
  desk1.add(interframe_1);
  interframe_2=new JInternalFrame("内窗体2",true,true,true,true);
  interframe_2.setSize(300,150);
  interframe_2.getContentPane().add(button2,BorderLayout.CENTER);
  interframe_2.getContentPane().add(new JLabel("ookk"),BorderLayout.NORTH); 
  JDesktopPane  desk2=new JDesktopPane();
  desk2.add(interframe_2);
  con.add(desk1);con.add(desk2);
  addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
        {System.exit(0);}});
   }
}
public class Exam25_9
{ public static void main(String args[])
  { Mywindow win=new Mywindow();win.pack();
  }
}



25-例子10
import javax.swing.*;import java.awt.*;import java.awt.event.*;
class Mywindow extends JFrame implements ActionListener
{ JButton button1,button2,button3;JTextArea text;Icon icon;
   Mywindow()
   {setSize(200,200);setVisible(true);
    Container con=getContentPane();
    text=new JTextArea(); 
    con.setLayout(new GridLayout(1,4)); 
    icon=new ImageIcon("tom.jpg");
    button1=new JButton("Boy",icon); button2=new JButton("Girl");
    button3=new JButton("friend",new ImageIcon("tom1.jpg"));
    button1.setVerticalTextPosition(AbstractButton.TOP);
    button1.setMnemonic('b'); 
    con.add(button1);con.add(button2);con.add(button3);con.add(text);
    button1.addActionListener(this);button3.addActionListener(this);
    addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
        {System.exit(0);}});
   }
  public void actionPerformed(ActionEvent e)
  {if(e.getSource()==button1)
    { text.setText(button1.getText()+button2.getText());
      button2.setIcon(button1.getIcon());
      button2.setHorizontalTextPosition(AbstractButton.RIGHT);button3.setEnabled(false);
    }
  else if(e.getSource()==button3)
    { text.append(button3.getText()); button2.setIcon(button3.getIcon());
     }
  }
}
public class Example25_10
{ public static void main(String args[])
  { Mywindow win=new Mywindow();win.pack();
  }
}



25-例子11
import javax.swing.*;import java.awt.BorderLayout;
import java.awt.event.*;import java.awt.*;
public class Example25_11 extends JApplet implements ActionListener 
{ JLabel label_1,label_2;JButton button;JTextArea text;
  public void init()
  { button=new JButton("确定");text=new JTextArea();
    Icon icon=new ImageIcon("tom.jpg");
    label_1=new JLabel("标签1",icon,JLabel.CENTER); label_2=new JLabel("标签2");
    getContentPane().add(text,BorderLayout.CENTER); 
    getContentPane().add(button,BorderLayout.WEST); 
    getContentPane().add(label_1,BorderLayout.NORTH);
    getContentPane().add(label_2,BorderLayout.SOUTH);
    button.addActionListener(this);
  } 
 public void actionPerformed(ActionEvent e)
 {if(e.getSource()==button)
{label_2.setIcon(label_1.getIcon());text.setText(label_1.getText()+label_2.getText());}
   button.setIcon(label_1.getIcon());
   label_1.setHorizontalTextPosition(JLabel.LEFT); 
  }
 }



25-例子12
import javax.swing.*;import java.awt.BorderLayout;
import java.awt.event.*;import java.awt.*;
public class Example25_12 extends JApplet
 implements ActionListener,ItemListener
{ JCheckBox checkbox_1,checkbox_2,checkbox_3;
  JButton button;JTextArea text;
  public void init()
  { button=new JButton("确定");text=new JTextArea();
    Icon icon1=new ImageIcon("hello.jpg");
    Icon icon2=new ImageIcon("faint.jpg");
    checkbox_1=new JCheckBox("同意",icon1); 
    checkbox_2=new JCheckBox("反对",icon2);
    checkbox_3=new JCheckBox("不知道");
    Container con=getContentPane();
    con.setLayout(new FlowLayout()); 
    con.add(checkbox_1); con.add(checkbox_2);
    con.add(checkbox_3);   con.add(button);
    button.addActionListener(this);
    checkbox_3.addItemListener(this);
  } 
 public void actionPerformed(ActionEvent e)
 {if(e.getSource()==button)
   {checkbox_2.setIcon(checkbox_1.getIcon());
     text.setText(checkbox_1.getText()+checkbox_2.getText());
     button.setIcon(checkbox_2.getIcon());
   }
 }
 public void itemStateChanged(ItemEvent e)
 {if(e.getItemSelectable()==checkbox_3)
    {button.setText(checkbox_3.getText());
    } 
 } 
}



25-例子13
import javax.swing.*;
import java.awt.*;import java.awt.event.*;
class Mywindow extends JFrame implements ItemListener
{ JRadioButton button1,button2,button3;ButtonGroup fruit;
  JLabel label ;JScrollPane scroll;JPanel panel;JSplitPane split;
   Mywindow()
   { 
   setSize(200,400);setVisible(true);
   Container con=getContentPane();  fruit=new ButtonGroup();
   button1=new JRadioButton("苹果");fruit.add(button1);
   button2=new JRadioButton("香蕉");fruit.add(button2);
   button3=new JRadioButton("西瓜");fruit.add(button3);
   label=new JLabel();panel=new JPanel();
   scroll=new JScrollPane(label);
   panel.add(button1);panel.add(button2);panel.add(button3);
   split=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true,panel, scroll);
   con.add(split);
   button1.addItemListener(this);button2.addItemListener(this);
   button3.addItemListener(this);
   addWindowListener(new WindowAdapter()
      {public void windowClosing(WindowEvent e)
        {System.exit(0);}});
   }
  public void itemStateChanged(ItemEvent e)
  {if(e.getItemSelectable()==button1)
    {label.setIcon(new ImageIcon("a.jpg")); }
   else if(e.getItemSelectable()==button2)
    {label.setIcon(new ImageIcon("b.jpg")); }
   else if(e.getItemSelectable()==button3)
    {label.setIcon(new ImageIcon("c.jpg")); }
  }
}
public class Example25_13
{ public static void main(String args[])
  { Mywindow win=new Mywindow();win.pack();
  }
}



25-例子14
import javax.swing.*;import java.awt.*;import java.awt.event.*; import java.net.*;
public class Example25_14 extends JApplet implements ItemListener
{ JComboBox choice1,choice2; JSplitPane split1,split2;
  JLabel label; URL url;
  public void init()
  { Container con=getContentPane(); String[] s={"苹果", "香蕉" ,"西瓜"};
    choice1=new JComboBox(s);choice2=new JComboBox();
    label=new JLabel();choice2.setEditable(true);
   split1=newJSplitPane(JSplitPane.HORIZONTAL_SPLIT,true,choice1,choice2);
   split2=new JSplitPane(JSplitPane.VERTICAL_SPLIT,true,split1,label);
   choice1.addItemListener(this);choice2.addItemListener(this);con.add(split2);
  }   
  public void itemStateChanged(ItemEvent e)
  { if(e.getItemSelectable()==choice1)
        { if(choice1.getSelectedIndex()==0)
         { label.setIcon(new ImageIcon("a.jpg"));}
         else if(choice1.getSelectedIndex()==1)
         { label.setIcon(new ImageIcon("b.jpg")); } 
         else if(choice1.getSelectedIndex()==2)
         {label.setIcon(new ImageIcon("c.jpg"));} 
       }      
    else if(e.getItemSelectable()==choice2) 
       { try{url=new URL((String)choice2.getSelectedItem());
           　　 label.setText("你正在连接到："+choice2.getSelectedItem());
          　 }
         catch(MalformedURLException g)
           { label.setText("不正确的URL:"+url); }
        getAppletContext().showDocument(url);
       }
 }
}



25-例子15
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Example25_15 extends JApplet implements ActionListener
{ JTextField text1;JPasswordField text2; JTextArea textarea;
  JSplitPane split1,split2;
  public void init()
  { Container con=getContentPane();
    text1=new JTextField(8);text2=new JPasswordField(12);
    text2.setEchoChar('*');textarea=new JTextArea(10,10);
    textarea.setLineWrap(true);
    textarea.setWrapStyleWord(true);
    JPanel p1=new JPanel();JPanel p2=new JPanel();
    p1.add(new Label("输入姓名"));p1.add(text1);
    p2.add(new Label("输入密码"));p2.add(text2);
    split1=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true,p1,p2);
    JScrollPane pane=new JScrollPane(textarea); 
    split2=new JSplitPane(JSplitPane.VERTICAL_SPLIT,true,split1,pane);
    text2.addActionListener(this);
    con.add(split2,BorderLayout.CENTER);
  }   
  public void actionPerformed(ActionEvent e)
  {  
    if(e.getSource()==text2)
       { String s=new String(text2.getPassword());
         if(s.equals("1999"))
      textarea.setText("相聚2000，欢迎光临！"); 
         else 
          {textarea.setText("密码不正确");text2.setText(null);}
       }
  }