ITJS的这篇文章主要介绍了Java的图形设计以及多媒体处理，源码作者也做了详细的注释，对于初学者应该不难。详细请看下文。
同心圆效果图：
/**
*程序要求：新建一个600*600像素的应用程序窗口，并在窗口中绘制5个不同颜色的同心圆，
*所有圆心都是屏幕的中心点，相邻两个圆直接的半径相差50像素
*效果图如下图所示（颜色随机设置），源程序保存为Ex7_1.java。
*作者：wwj
*日期：2012/4/25
*功能：显示一个有5个不同颜色的同心圆
**/
import javax.swing.*;
import java.awt.*;
import java.awt.Color;
public class Ex7_1 extends JFrame
{
int red,green,blue;
Color color;
public Ex7_1()
{
super("一个有5个不同颜色的同心圆"); //显示窗口名称
setSize(600,600); //设置窗口大小
setVisible(true); //设置为可见
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设置窗口关闭动作
}
public void paint(Graphics g)
{
//第一个圆
red=(int)(Math.random()*255);
green=(int)(Math.random()*255);
blue=(int)(Math.random()*255);
color=new Color(red,green,blue);
g.setColor(color);
g.fillOval(175,175,250,250);
//第二个圆
red=(int)(Math.random()*255);
green=(int)(Math.random()*255);
blue=(int)(Math.random()*255);
color=new Color(red,green,blue);
g.setColor(color);
g.fillOval(200,200,200,200);
//第三个圆
red=(int)(Math.random()*255);
green=(int)(Math.random()*255);
blue=(int)(Math.random()*255);
color=new Color(red,green,blue);
g.setColor(color);
g.fillOval(225,225,150,150);
//第四个圆
red=(int)(Math.random()*255);
green=(int)(Math.random()*255);
blue=(int)(Math.random()*255);
color=new Color(red,green,blue);
g.setColor(color);
g.fillOval(250,250,100,100);
//第五个圆
red=(int)(Math.random()*255);
green=(int)(Math.random()*255);
blue=(int)(Math.random()*255);
color=new Color(red,green,blue);
g.setColor(color);
g.fillOval(275,275,50,50);
}
public static void main(String[] args)
{
Ex7_1 e = new Ex7_1();
}
}
播放音乐和切换图片的小程序效果图：
/**
*程序要求:编写一个Applet的小程序，准备5幅图片和三个音乐文件，绘制到Applet中，
*并增加几个按钮，控制图片的切换、放大、缩小和音乐文件的播放。
*作者：wwj
*日期：2012/4/29
*参考：neicole
*功能：能进行图片和歌曲的选择变换的applet小程序
**/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
import java.applet.AudioClip;
public class Ex7_2 extends Applet implements ActionListener,ItemListener
{
//创建两个面板
JPanel p1=new JPanel();
JPanel p2=new JPanel();
JPanel p3=new JPanel();
//声音对象
AudioClip[] sound=new AudioClip[3];
int playingSong=0;
//切换图片的按钮
JButton lastPic=new JButton("上一张");
JButton setLarge=new JButton("放大");
JButton setLittle=new JButton("缩小");
JButton nextPic=new JButton("下一张");
//切换歌曲的按钮
JButton lastSound=new JButton("上一首");
JButton play=new JButton("播放");
JButton loop=new JButton("连续");
JButton stop=new JButton("停止");
JButton nextSound=new JButton("下一首");
//曲目下拉列表
JComboBox xx;
String names[]={ "曲目1.wav","曲目2.wav","曲目3.wav"};
//创建画布对象
MyCanvasl showPhotos;
public void init()
{
//窗口布局
this.setLayout(new BorderLayout());
//为图片控制按钮注册监听器
lastPic.addActionListener(this);
setLarge.addActionListener(this);
setLittle.addActionListener(this);
nextPic.addActionListener(this);
//向面板p1添加组件
p1.add(lastPic);
p1.add(setLarge);
p1.add(setLittle);
p1.add(nextPic);
p1.repaint();
//实例化下拉列表对象
xx = new JComboBox(names);
xx.addItemListener(this);
//为控制播放音乐按钮注册监听器
lastSound.addActionListener(this);
play.addActionListener(this);
loop.addActionListener(this);
stop.addActionListener(this);
nextSound.addActionListener(this);
for(int i=0;i<3;i++)
{
sound[i]=getAudioClip(getCodeBase(),"music/"+"曲目"
+Integer.toString(i+1)+".wav");
}
//向面板p2添加组件
p2.add(xx);
p2.add(lastSound);
p2.add(play);
p2.add(loop);
p2.add(stop);
p2.add(nextSound);
p2.repaint();
showPhotos = new MyCanvasl();
p3.add(showPhotos);
p3.repaint();
//把面板p1和p2分别布置到窗口的北部和南部
add(p1,BorderLayout.NORTH);
add(p2,BorderLayout.SOUTH);
add(p3,BorderLayout.CENTER);
this.repaint();
}
//按钮的事件处理
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == lastPic){
showPhotos.changePhotoShow('P');
}
else if(e.getSource() == nextPic){
showPhotos.changePhotoShow('N');
}
else if(e.getSource() == setLarge){
showPhotos.changePhotoSize('B');
}
else if(e.getSource() == setLittle){
showPhotos.changePhotoSize('S');
}
else if(e.getSource()==lastSound){ //上一首
sound[playingSong].stop();
playingSong=(playingSong-1+3)%3;
xx.setSelectedIndex(playingSong);
sound[playingSong].play();
}
else if(e.getSource()==play){ //按下播放按钮
sound[playingSong].play();
}
else if(e.getSource()==loop){ //按下循环按钮
sound[playingSong].loop();
}
else if(e.getSource()==stop){ //按下停止按钮
sound[playingSong].stop();
}
else{ //下一首
sound[playingSong].stop();
playingSong=(playingSong+1)%3;
xx.setSelectedIndex(playingSong);
sound[playingSong].play();
}
}
//下拉列表的事件处理
public void itemStateChanged(ItemEvent e)
{
sound[playingSong].stop();
sound[playingSong]=getAudioClip(getCodeBase(),"music/"+xx.getSelectedItem());
}
class MyCanvasl extends Canvas
{
public Image[] img=new Image[5];
int MaxWidth = 600;
int MaxHeight = 500;
int nowImageIndex = 0;
int coordinateX = 0;
int coordinateY = 0;
int currentWidth = MaxWidth;
int currentHeight = MaxHeight;
MyCanvasl(){
setSize(MaxWidth,MaxHeight);
//获取当前目录下的图片
for(int i=0;i<5;i++){
img[i]=getImage(getCodeBase(),"image/"+Integer.toString(i+1)+".jpg");
}
}
private void changePhotoIndex(int index){
nowImageIndex = index;
changePhotoSize('M');
}
public void changePhotoShow(char command){
if('P' == command){
changePhotoIndex((nowImageIndex + 5 - 1 ) % 5);
}
else if('N' == command){
changePhotoIndex((nowImageIndex + 1) % 5);
}
}
public void changePhotoSize(char command){
if ('M' == command){
currentWidth = MaxWidth;
currentHeight = MaxHeight;
}
else if ('B' == command){
if(MaxWidth >= (currentWidth + 100) && MaxHeight >= (currentHeight + 100)){
currentWidth += 100;
currentHeight += 100;
}
}
else if('S' == command){
if((0 < (currentWidth - 100)) && (0 < (currentHeight - 100))){
currentWidth = currentWidth - 100;
currentHeight = currentHeight - 100;
}
}
coordinateX = (MaxWidth - currentWidth) / 2;
coordinateY = (MaxHeight - currentHeight) / 2;
repaint();
}
//paint方法用来在窗口显示图片
public void paint(Graphics g){
g.drawImage(img[nowImageIndex],coordinateX,coordinateY,currentWidth,currentHeight,this);
}
}
}