package guitest.myboard;import java.awt.*;import java.awt.event.*;import java.awt.geom.*;import java.io.*;import java.util.*;import javax.swing.*;//the point //impress the info of one point,the x and yclass OnePoint implements Serializable { int x; int y; int tool; Color c; int border;  public OnePoint(int x,int y,int tool,Color cc,int border){  this.x=x;  this.y=y;  this.tool=tool;  this.c=cc;  this.border=border; }}class DrawingBoard extends Frame implements MouseListener,ItemListener,ActionListener,MouseMotionListener{  Button pen; Button line ; Button ellipse ; Button rect ; Button clear ; Button colorboard ;  Button storebutton; Button openbutton;  Choice sizechoice ; Choice colorchoice ;  Label pensize; Label pencolor; Panel panel ;  FileDialog  storefile; FileDialog  openfile;  FileInputStream filein; FileOutputStream fileout; ObjectInputStream objectin; ObjectOutputStream objectout;  int flagtool=0; Color flagcolor; int border; BasicStroke size;  OnePoint p1,p2; Vector<OnePoint> points=new Vector<OnePoint>();  public DrawingBoard(){  pen=new Button("画笔");  line=new Button("直线");  ellipse=new Button("圆");  rect=new Button("矩形");  clear=new Button("清除");  colorboard=new Button("调色板");  storebutton=new Button("存储文件");  openbutton=new Button("打开文件");    pensize=new Label("画笔大小");  pencolor=new Label("画笔颜色");    storefile=new FileDialog(this,"存储文件",FileDialog.SAVE);  storefile.setVisible(false);  storefile.addWindowListener(new WindowAdapter(){   public void windowClosing(WindowEvent e){    storefile.setVisible(false);   }  });  openfile=new FileDialog(this,"打开文件",FileDialog.LOAD);  openfile.setVisible(false);  openfile.addWindowListener(new WindowAdapter(){   public void windowClosing(WindowEvent e){    openfile.setVisible(false);   }  });    sizechoice=new Choice();  sizechoice.add("1");  sizechoice.add("2");  sizechoice.add("4");  sizechoice.add("6");  sizechoice.add("8");  sizechoice.addItemListener(this);    colorchoice=new Choice();  colorchoice.add("black");  colorchoice.add("red");  colorchoice.add("blue");  colorchoice.add("green");  colorchoice.addItemListener(this);    pen.addActionListener(this);  line.addActionListener(this);  ellipse.addActionListener(this);  rect.addActionListener(this);  clear.addActionListener(this);  colorboard.addActionListener(this);  storebutton.addActionListener(this);  openbutton.addActionListener(this);    panel=new Panel();     panel.add(storebutton);  panel.add(openbutton);    panel.add(pen);  panel.add(line);  panel.add(ellipse);  panel.add(rect);  panel.add(clear);    panel.add(sizechoice);  panel.add(pensize);    panel.add(colorchoice);  panel.add(pencolor);  panel.add(colorboard);    add(panel,BorderLayout.NORTH);  setBounds(100,100,700,600);  setVisible(true);    addWindowListener(new WindowAdapter(){   public void windowClosing(WindowEvent e){    System.exit(0);   }  });    /**   * 添加鼠标事件的监听器，否则，鼠标的移动和点击都将无法识别！   * */  addMouseListener(this);  addMouseMotionListener(this); }  public void paint(Graphics g){    Graphics2D g2d=(Graphics2D)g;  if(flagtool==2){                    //qing chu   g.clearRect(0,0,getSize().width,getSize().height);  }  for(int i=0;i<points.size()-1;i++){   p1=(OnePoint)points.elementAt(i);   p2=(OnePoint)points.elementAt(i+1);      g2d.setColor(p1.c); //////////////需要使用Graphics2D从Graphics类中继承下来的方法 setColor（）设置当前的颜色   size=new BasicStroke(p1.border,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);   g2d.setStroke(size);      if(p1.tool==p2.tool){   switch(p1.tool){   case 0:      Line2D.Double line1=new Line2D.Double(p1.x,p1.y,p2.x,p2.y);    g2d.draw(line1);    break;   case 1:    Line2D.Double line2=new Line2D.Double(p1.x,p1.y,p2.x,p2.y);    g2d.draw(line2);    break;   case 3:    Ellipse2D.Double ellipse=new Ellipse2D.Double(p1.x,p1.y,Math.abs(p2.x-p1.x),Math.abs(p2.y-p1.y));    g2d.draw(ellipse);    break;   case 4:    Rectangle2D.Double rect=new Rectangle2D.Double(p1.x,p1.y,Math.abs(p2.x-p1.x),Math.abs(p2.y-p1.y));    g2d.draw(rect);    break;   default:   }    }  }  }  public void mouseClicked(MouseEvent e) {} public void mouseEntered(MouseEvent e) {} public void mouseExited(MouseEvent e) {} public void mousePressed(MouseEvent e) { //鼠标点下时候，将当前的点信息记录    OnePoint pp1=new OnePoint(e.getX(),e.getY(),flagtool,flagcolor,border);  points.addElement(pp1);  //repaint(); } public void mouseReleased(MouseEvent e) {//鼠标松开时候，如果是画笔，则当前截断，是其余状态记下一枚点信息  if(flagtool==0){   points.addElement(new OnePoint(-1,-1,22,flagcolor,border));  }  else{   OnePoint pp2=new OnePoint(e.getX(),e.getY(),flagtool,flagcolor,border);   points.addElement(pp2);   points.add(new OnePoint(-1,-1,22,flagcolor,border));  }  repaint(); } public void itemStateChanged(ItemEvent e) {  if(e.getSource()==colorchoice){   String selected=colorchoice.getSelectedItem();   if(selected=="black"){    flagcolor=new Color(0,0,0);   }   else if(selected=="red"){    flagcolor=new Color(255,0,0);   }   else if(selected=="blue"){    flagcolor=new Color(0,0,255);   }   else if(selected=="green"){    flagcolor=new Color(0,255,0);   }  }  else if(e.getSource()==sizechoice){   String selected=sizechoice.getSelectedItem();   if (selected=="1"){    border=1;   }   else if(selected=="2"){    border=2*2;   }   else if(selected=="4"){    border=4*2;   }   else if(selected=="6"){    border=6*2;   }   else if(selected=="8"){    border=8*2;   }  }   } public void update(Graphics g) {   //@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@  paint(g); } public void actionPerformed(ActionEvent e) {  // TODO Auto-generated method stub  if(e.getSource()==pen){   flagtool=0;  }  else if(e.getSource()==line){   flagtool=1;  }  else if(e.getSource()==clear){   flagtool=2;   points.removeAllElements();   repaint();      //此语要有，否则今生无法删除！  }  else if(e.getSource()==ellipse){   flagtool=3;  }  else if(e.getSource()==rect){   flagtool=4;  }  else if(e.getSource()==colorboard){   /*    * 使用 javax.swing.×包中的 JColorChooser 类的静态方法showDialog（Component component，String title，Color color ），    * 该方法的参数，component是当前显示对话框的父框架，color是设置调色板初始的被选颜色    *     * 该方法返回被选的颜色，类型为Color    * */   Color color=JColorChooser.showDialog(this, "调色板",flagcolor);   flagcolor=color;  }  else if(e.getSource()==openbutton){   openfile.setVisible(true);   if(openfile.getFile()!=null){       int temp=flagtool;    flagtool=2;    repaint();    try{     points.removeAllElements();     File file=new File(openfile.getDirectory(),openfile.getFile());     filein=new FileInputStream(file);     objectin=new ObjectInputStream(filein);     points=(Vector)objectin.readObject();     objectin.close();     filein.close();     flagtool=temp;     repaint();    }    catch(Exception ee){     System.out.println(ee.toString());    }   }  }  else if(e.getSource()==storebutton){   storefile.setVisible(true);   if(storefile.getFile()!=null){        try {     File file=new File(storefile.getDirectory(),storefile.getFile());     fileout=new FileOutputStream(file);     objectout=new ObjectOutputStream(fileout);     objectout.writeObject(points);     objectout.close();     fileout.close();     repaint();    }    catch (FileNotFoundException e1) {     System.out.println(e1.toString());     e1.printStackTrace();    } catch (IOException ee) {     System.out.println(ee.toString());     ee.printStackTrace();    }   }  } } public void mouseDragged(MouseEvent e) {//鼠标拖动时候，//当且仅当 flagtool＝＝0，或者表示为橡皮的时候           //才将拖动过程中涉及到的点全部记录下来，并且调用repain()方法，重画当前  // TODO Auto-generated method stub  if(flagtool==0){   OnePoint pp3=new OnePoint(e.getX(),e.getY(),flagtool,flagcolor,border);   points.addElement(pp3);   repaint();  } } public void mouseMoved(MouseEvent e) {  // TODO Auto-generated method stub   }}public class PaintBoard{ public static void main(String[] args){  DrawingBoard oneBorder=new DrawingBoard(); }}