Java循环播放图片问题

       昨日在论坛中看到一贴，用Java实现循环播放截图，遇到问题颇多，下面是他的描述：

    “播放连续截图的时候都是卡的我眼泪直流，而且JFrame窗体老变白，我在画图片之前又将背景绘制成全黑，还是一样，还有会出现白背景！另外就是，我在将播放的帧数设置为每秒20帧的时候(也就是每50ms画一帧)，根本就看不到图片出现；将其改为150ms的时候，也能看到图片的模糊影像，设置为两百的时候，才会出现上上面说的那种很卡的播放效果”

    卡是情有可原，可能JVM内存不足造成，这个可以通过加大JVM内存来解决；而窗体发白，背景发黑这种情况我倒是没遇见过，前段时间做过一个切图工具，图片超大时（17MB，游戏地图）是很卡，不够也能顺利切割；图片循环播放也是一个挺简单的问题，怎么会出现这样情况呢，会不会是界面重绘出了问题，动手试一试：

    下面是一个用于循环播放图片的DisplayJPanel，继承了类JPanel和接口Runnable，把这个DisplayJPanel放在上层容器如JScrollPane上传入参数即可，很简单的一段代码：

 

import java.awt.Color; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.util.ArrayList; import java.util.List; import javax.swing.JPanel; /** * * 循环播放图片 * * @author monitor * Created on 2010-12-22, 16:38:02 */ public class DisplayJPanel extends JPanel implements Runnable{ /** 背景颜色 */ private final Color B_COLOR=Color.LIGHT_GRAY; /** 起始X坐标 */ private final int WORK_X=10; /** 起始Y坐标 */ private final int WORK_Y=10; /** 要播放的图片 */ private List<BufferedImage> imageList=new ArrayList<BufferedImage>(); /** 当前要画的图片 */ private BufferedImage currentImage=null; /** 播放延时 */ private int delay=50; /** 是否播放 */ private boolean work=true; /** 是否暂停 */ private boolean stop=false; /** * 构造一个最初没有图片显示的DisplayJPanel对象 */ public DisplayJPanel(){ } /** * 构造一个带有要播放图片列表的DisplayJPanel对象 * @param imageList 要播放的图片列表 */ public DisplayJPanel(List<BufferedImage> imageList){ this.imageList=imageList; } /** * 循环播放图片列表 */ public void run(){ while(work){ if(stop || imageList==null || imageList.isEmpty()){ sleep(1000); continue; } for(BufferedImage image:imageList){ currentImage=image; repaint(); sleep(delay); } } } @Override public void paintComponent(Graphics g){ g.setColor(B_COLOR); g.fillRect(0, 0,this.getWidth(),this.getHeight()); if(currentImage!=null){ g.drawImage(currentImage,WORK_X,WORK_Y,null); } } /** * 线程睡眠 * @param s 睡眠时间（ms） */ private void sleep(int s){ try{ Thread.sleep(s); }catch(Exception e){ } } /** * 设置播放帧延时 * @param delay 帧延时（ms） */ public void setDelay(int delay) { this.delay = delay; } /** * 设置要播放的图片列表 * @param imageList 要播放的图片列表 */ public void setImageList(List<BufferedImage> imageList) { this.imageList = imageList; } /** * 设置是否播放 * @param work ture 播放，false 不播放 */ public void setWork(boolean work) { this.work = work; } /** * 设置是否暂停 * @param stop ture 暂停，false 不暂停 */ public void setStop(boolean stop) { this.stop = stop; } }

    用Netbeans做了很简单的边框布局的界面，界面效果如下：

    代码如下：

 package com.monitor.imagetest; import java.awt.Dimension; import java.awt.Toolkit; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.List; import java.util.logging.Level; import java.util.logging.Logger; import javax.imageio.ImageIO; import javax.swing.DefaultListModel; import javax.swing.JFileChooser; import javax.swing.JOptionPane; /* * MainUI.java * * 图片循环播放 * * @author monitor * Created on 2010-12-22, 16:49:47 */ public class MainUI extends javax.swing.JFrame { private DisplayJPanel display=null; private DefaultListModel imageModel=new DefaultListModel(); private List<BufferedImage> imageList=new ArrayList<BufferedImage>(); /** * 构造一个MainUI对象 */ public MainUI() { initComponents(); init(); } /** * 界面初始化 */ private void init(){ //居中显示 Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); int screenWidth=(int)screenSize.getWidth(); int screenHeight=(int)screenSize.getHeight(); int width=this.getWidth(); int height=this.getHeight(); this.setBounds((screenWidth-width)/2,(screenHeight-height)/2,width ,height); display=new DisplayJPanel(); imagePane.setViewportView(display); new Thread(display).start(); //进度图不可视 bar.setVisible(false); } @SuppressWarnings("unchecked") // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents private void initComponents() { jPanel1 = new javax.swing.JPanel(); jLabel1 = new javax.swing.JLabel(); jPanel2 = new javax.swing.JPanel(); msgLabel = new javax.swing.JLabel(); bar = new javax.swing.JProgressBar(); jPanel3 = new javax.swing.JPanel(); jPanel4 = new javax.swing.JPanel(); jLabel2 = new javax.swing.JLabel(); delaySpin = new javax.swing.JSpinner(); jToolBar1 = new javax.swing.JToolBar(); importButton = new javax.swing.JButton(); playButton = new javax.swing.JButton(); stopButton = new javax.swing.JButton(); goonButton = new javax.swing.JButton(); imagePane = new javax.swing.JScrollPane(); jScrollPane1 = new javax.swing.JScrollPane(); imageJList = new javax.swing.JList(); jMenuBar1 = new javax.swing.JMenuBar(); jMenu1 = new javax.swing.JMenu(); jMenu2 = new javax.swing.JMenu(); jMenu3 = new javax.swing.JMenu(); setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); jLabel1.setFont(new java.awt.Font("宋体", 0, 36)); jLabel1.setText("图片播放"); jPanel1.add(jLabel1); getContentPane().add(jPanel1, java.awt.BorderLayout.PAGE_START); jPanel2.setBorder(javax.swing.BorderFactory.createEtchedBorder()); jPanel2.setLayout(new java.awt.GridLayout(1, 0)); jPanel2.add(msgLabel); jPanel2.add(bar); getContentPane().add(jPanel2, java.awt.BorderLayout.PAGE_END); jPanel3.setBorder(javax.swing.BorderFactory.createEmptyBorder(1, 1, 1, 1)); jPanel4.setBorder(javax.swing.BorderFactory.createEtchedBorder()); jLabel2.setText("播放延时(ms)："); delaySpin.setModel(new javax.swing.SpinnerNumberModel(Integer.valueOf(50), Integer.valueOf(10), null, Integer.valueOf(1))); delaySpin.addChangeListener(new javax.swing.event.ChangeListener() { public void stateChanged(javax.swing.event.ChangeEvent evt) { delaySpinStateChanged(evt); } }); jToolBar1.setRollover(true); importButton.setText("导入"); importButton.setFocusable(false); importButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); importButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM); importButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { importButtonActionPerformed(evt); } }); jToolBar1.add(importButton); playButton.setText("播放"); playButton.setFocusable(false); playButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); playButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM); playButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { playButtonActionPerformed(evt); } }); jToolBar1.add(playButton); stopButton.setText("暂停"); stopButton.setFocusable(false); stopButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); stopButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM); stopButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { stopButtonActionPerformed(evt); } }); jToolBar1.add(stopButton); goonButton.setText("继续"); goonButton.setFocusable(false); goonButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); goonButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM); goonButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { goonButtonActionPerformed(evt); } }); jToolBar1.add(goonButton); javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4); jPanel4.setLayout(jPanel4Layout); jPanel4Layout.setHorizontalGroup( jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel4Layout.createSequentialGroup() .addComponent(jLabel2) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(delaySpin, javax.swing.GroupLayout.PREFERRED_SIZE, 59, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(jToolBar1, javax.swing.GroupLayout.DEFAULT_SIZE, 531, Short.MAX_VALUE)) ); jPanel4Layout.setVerticalGroup( jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.CENTER) .addComponent(jToolBar1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addComponent(delaySpin, javax.swing.GroupLayout.DEFAULT_SIZE, 23, Short.MAX_VALUE) .addComponent(jLabel2)) ); imageJList.setModel(imageModel); jScrollPane1.setViewportView(imageJList); javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3); jPanel3.setLayout(jPanel3Layout); jPanel3Layout.setHorizontalGroup( jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel3Layout.createSequentialGroup() .addContainerGap() .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING) .addGroup(jPanel3Layout.createSequentialGroup() .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 150, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(imagePane, javax.swing.GroupLayout.DEFAULT_SIZE, 532, Short.MAX_VALUE)) .addComponent(jPanel4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) .addContainerGap()) ); jPanel3Layout.setVerticalGroup( jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel3Layout.createSequentialGroup() .addContainerGap() .addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 278, Short.MAX_VALUE) .addComponent(imagePane, javax.swing.GroupLayout.DEFAULT_SIZE, 278, Short.MAX_VALUE)) .addContainerGap()) ); getContentPane().add(jPanel3, java.awt.BorderLayout.CENTER); jMenu1.setText("文件"); jMenuBar1.add(jMenu1); jMenu2.setText("编辑"); jMenuBar1.add(jMenu2); jMenu3.setText("编辑"); jMenuBar1.add(jMenu3); setJMenuBar(jMenuBar1); pack(); }// </editor-fold>//GEN-END:initComponents /** * 用线程导入图片，并在界面显示信息 * @param evt 触发事件 */ private void importButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_importButtonActionPerformed new Thread(new Runnable() { public void run() { JFileChooser fileChooser = new JFileChooser(); fileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY); int flag=fileChooser.showOpenDialog(null); if(flag!=JFileChooser.APPROVE_OPTION){ return; } File importFile = fileChooser.getSelectedFile(); if (importFile==null) { return; } imageModel.removeAllElements(); int i=1; bar.setVisible(true); bar.setIndeterminate(true); for(File file:importFile.listFiles()){ try { msgLabel.setText("正在导入："+file.getName()); imageList.add(ImageIO.read(file)); imageModel.addElement(file.getName()); i++; } catch (IOException ex) { System.out.println("非图片文件"); //Logger.getLogger(MainUI.class.getName()).log(Level.SEVERE, null, ex); } } bar.setVisible(false); msgLabel.setText("导入完毕！共"+i+"张图片，播放图片请点击“播放”按钮"); }}).start(); }//GEN-LAST:event_importButtonActionPerformed /** * 播放 * @param evt */ private void playButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_playButtonActionPerformed if(imageList==null || imageList.isEmpty()){ String msg="请输入导入要播放的图片"; JOptionPane.showMessageDialog(this, msg , "提示", JOptionPane.INFORMATION_MESSAGE); return; } display.setImageList(imageList); }//GEN-LAST:event_playButtonActionPerformed /** * 修改帧延时 * @param evt */ private void delaySpinStateChanged(javax.swing.event.ChangeEvent evt) {//GEN-FIRST:event_delaySpinStateChanged int delay=(Integer)delaySpin.getValue(); if(delay>=10){ display.setDelay(delay); } }//GEN-LAST:event_delaySpinStateChanged /** * 暂停 * @param evt */ private void stopButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_stopButtonActionPerformed display.setStop(true); }//GEN-LAST:event_stopButtonActionPerformed /** * 继续 * @param evt */ private void goonButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_goonButtonActionPerformed display.setStop(false); }//GEN-LAST:event_goonButtonActionPerformed // Variables declaration - do not modify//GEN-BEGIN:variables private javax.swing.JProgressBar bar; private javax.swing.JSpinner delaySpin; private javax.swing.JButton goonButton; private javax.swing.JList imageJList; private javax.swing.JScrollPane imagePane; private javax.swing.JButton importButton; private javax.swing.JLabel jLabel1; private javax.swing.JLabel jLabel2; private javax.swing.JMenu jMenu1; private javax.swing.JMenu jMenu2; private javax.swing.JMenu jMenu3; private javax.swing.JMenuBar jMenuBar1; private javax.swing.JPanel jPanel1; private javax.swing.JPanel jPanel2; private javax.swing.JPanel jPanel3; private javax.swing.JPanel jPanel4; private javax.swing.JScrollPane jScrollPane1; private javax.swing.JToolBar jToolBar1; private javax.swing.JLabel msgLabel; private javax.swing.JButton playButton; private javax.swing.JButton stopButton; // End of variables declaration//GEN-END:variables }

        我也测试了一下，从屏幕截了一张图，尺寸为1081*636大小为139KB的JPG图片，共复制了424张，总大小57.9MB，给程序分配了900MB内存（不能少于700MB），导入图片时另开线程导入；播放没有问题，很流畅，没有出现界面发白背景发黑的情况。

    一次把图片都加载到内存这种方案最大的不足就是当图片很多很大时要耗费大量的内存，容易出现内存溢出错误，难于控制。可以改成实时加载的方案，要画到的图片才用ImageIO从文件读取，画完就释放，当播放速度不是很快时这完全满足要求。