java生成长方形图片

『壹』 用java语言写一个二维平面图形(如长方形)的平移,旋转,缩放的程序.

importjavax.swing.*;

importjava.awt.*;

importjava.awt.event.ActionEvent;

importjava.awt.geom.*;

/**

*@

*/

{

=newDimension(300,200);

=newDimension(1024,768);

=newDimension(600,400);

publicDimensiongetMaximumSize(){returnmaxSize;}

publicDimensiongetMinimumSize(){returnminSize;}

(){returnpreferredSize;}

publicStringgetTitle(){return"FrameTitle";}

privateAffineTransformaf=newAffineTransform();

privateStrokestroke=newBasicStroke(2.0f);

privateRectanglerct=newRectangle(40,140,200,140);

privateJComponentcanvas=newJComponent(){

protectedvoidpaintComponent(Graphicsg){

super.paintComponent(g);

g.setColor(Color.BLACK);

g.fillRect(0,0,getWidth(),getHeight());

Graphics2Dg2d=(Graphics2D)g.create();

g2d.setColor(Color.YELLOW);

g2d.setTransform(af);

g2d.setStroke(stroke);

g2d.draw(rct);

g2d.dispose();

}

};

RectTransform()throwsHeadlessException{

init();

doLay();

attachListeners();

}

privatevoidinit(){

}

privatevoiddoLay(){

Containercontainer=getContentPane();

JPanelpanel=newJPanel(newFlowLayout(FlowLayout.CENTER,30,5));

panel.add(newJButton(newAfAction("move",AffineTransform.getTranslateInstance(100,100))));

panel.add(newJButton(newAfAction("rotate",AffineTransform.getRotateInstance(Math.PI/3,40,120))));

panel.add(newJButton(newAfAction("zoomIn",AffineTransform.getScaleInstance(2,2))));

panel.add(newJButton(newAfAction("ZoomOut",AffineTransform.getScaleInstance(.5d,.5d))));

panel.add(newJButton(newAfAction("Original",newAffineTransform())));

container.add(panel,BorderLayout.NORTH);

container.add(canvas,BorderLayout.CENTER);

pack();

}

privatevoidattachListeners(){

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

{

privateAffineTransformaff;

privateAfAction(Stringn,AffineTransformaf){

super(n);

this.aff=af;

}

publicvoidactionPerformed(ActionEvente){

af.setTransform(aff);

if(canvas.isVisible())canvas.paintImmediately(0,0,getWidth(),getHeight());

}

}

publicstaticvoidmain(String[]args){

newRectTransform().setVisible(true);

}

}

『贰』 java代码实现缩放图片,长方形图片变成正方形,上下保留空白区域.

那就把正方形的边长设置成长方形最长的变那么长
不就可以了吗