论音乐播放器的正确编写姿势 - 黑马程序员技术交流社区

package tiantian;
import java.io.IOException;
import java.net.URL;
import javax.media.Manager;
import javax.media.NoPlayerException;
import javax.media.Player;
import javax.swing.JOptionPane;
public class Music {
private Player player=null;
private URL url=null;
public Music(URL url){
this.url=url;
}
public void initPlayer(){
if(this.url!=null)
try {
player=Manager.createPlayer(this.url);
} catch (NoPlayerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public URL getUrl() {
return url;
}
public void setUrl(URL url) {
this.url = url;
}
public void play(){
if(player==null)
JOptionPane.showMessageDialog(null, "请选中音乐再播放！", "出错啦！", JOptionPane.ERROR_MESSAGE);
else
player.start();
}
public void stop(){
if(player==null)
JOptionPane.showMessageDialog(null, "请选中音乐再停止！", "出错啦！", JOptionPane.ERROR_MESSAGE);
else{
player.stop();
player.close();
}
}
}

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package tiantian;
import java.io.File;
import java.net.MalformedURLException;
public class Demo {
public static void main(String[] args) throws MalformedURLException {
File file=new File("E:\\test.mp3");
Music music=new Music(file.toURL());
music.initPlayer();
music.play();
}
}

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package tiantian;
import java.applet.Applet;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import javax.media.Manager;
import javax.media.NoPlayerException;
import javax.media.Player;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class MusicPanel extends JPanel implements ActionListener{
private File file;//播放文件
private JLabel jfStatus;//状态栏
private JButton jbPlay;//播放按钮
private JButton jbStop;//停止按钮
private JButton jbOpen;//打开文件按钮
private JButton jbClose;//关闭文件按钮
private Music music;//音乐播放类
public MusicPanel() throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());//将界面转化成windows风格
// UIManager.setLookAndFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel");
// UIManager.setLookAndFeel("com.apple.mrj.swing.MacLookAndFeel");
jfStatus=new JLabel("未选择文件");//状态栏初始化
jbPlay=new JButton("播放");//四大按钮初始化，并添加监听
jbPlay.addActionListener(this);
jbStop=new JButton("停止");
jbStop.addActionListener(this);
jbOpen=new JButton("打开");
jbOpen.addActionListener(this);
jbClose=new JButton("关闭");
jbClose.addActionListener(this);
//panel界面初始化
this.setSize(360, 100);
this.setVisible(true);
//布局初始化
//思来想去我决定先用GridBagLayout，虽然很复杂，但是很精确。
GridBagLayout gbl=new GridBagLayout();
gbl.columnWidths=new int[]{7,7,7,7,7,7,7,7};
gbl.rowHeights=new int[]{7,7,7,7,7,7,7,7};
this.setLayout(gbl);
GridBagConstraints gbc0=new GridBagConstraints();
gbc0.weighty = 0.1;
gbc0.weightx = 0.1;
gbc0.gridy = 1;
gbc0.gridx = 1;
gbc0.gridwidth=8;
gbc0.fill = GridBagConstraints.HORIZONTAL;
gbc0.anchor = GridBagConstraints.CENTER;
this.add(jfStatus,gbc0);
GridBagConstraints gbc1=new GridBagConstraints();
gbc1.weighty = 0.1;
gbc1.weightx = 0.1;
gbc1.gridy = 2;
gbc1.gridx = 1;
gbc1.fill = GridBagConstraints.HORIZONTAL;
gbc1.anchor = GridBagConstraints.CENTER;
this.add(jbOpen,gbc1);
GridBagConstraints gbc2=new GridBagConstraints();
gbc2.weighty = 0.1;
gbc2.weightx = 0.1;
gbc2.gridy = 2;
gbc2.gridx = 3;
gbc2.fill = GridBagConstraints.HORIZONTAL;
gbc2.anchor = GridBagConstraints.CENTER;
this.add(jbClose,gbc2);
GridBagConstraints gbc3=new GridBagConstraints();
gbc3.weighty = 0.1;
gbc3.weightx = 0.1;
gbc3.gridy = 2;
gbc3.gridx = 5;
gbc3.fill = GridBagConstraints.HORIZONTAL;
gbc3.anchor = GridBagConstraints.CENTER;
this.add(jbPlay,gbc3);
GridBagConstraints gbc4=new GridBagConstraints();
gbc4.weighty = 0.1;
gbc4.weightx = 0.1;
gbc4.gridy = 2;
gbc4.gridx = 7;
gbc4.fill = GridBagConstraints.HORIZONTAL;
gbc4.anchor = GridBagConstraints.CENTER;
this.add(jbStop,gbc4);
}
@Override
public void actionPerformed(ActionEvent e) {
if(e.getSource()==jbPlay){
this.play();
}
if(e.getSource()==jbStop){
this.stop();
}
if(e.getSource()==jbOpen){
this.openFile();
}
if(e.getSource()==jbClose){
this.closeFile();
}
}
//关闭文件
private void closeFile() {
this.music=null;
this.jfStatus.setText("未选择文件");
}
//打开文件
private void openFile() {
JFileChooser jfc=new JFileChooser();
if(jfc.showOpenDialog(this)==JFileChooser.APPROVE_OPTION){
this.file=jfc.getSelectedFile();
jfStatus.setText(file.getName());
}
}
//停止
private void stop() {
music.stop();
}
//播放
private void play() {
try {
this.music=new Music(file.toURL());
} catch (MalformedURLException e) {
e.printStackTrace();
}
this.music.initPlayer();
this.music.play();
}
}

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package tiantian;
import java.net.MalformedURLException;
import javax.swing.JFrame;
import javax.swing.UnsupportedLookAndFeelException;
public class Demo {
public static void main(String[] args) throws MalformedURLException, ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {
MusicPanel mp=new MusicPanel();
JFrame jf=new JFrame();
jf.add(mp);
jf.pack();
jf.setVisible(true);
jf.setLocationRelativeTo(null);
}
}

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@Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
}
@Override
public void mouseEntered(MouseEvent e) {
ImageIcon icon = new ImageIcon("image\\play_over.png");
this.jbPlay.setIcon(icon);
}
@Override
public void mouseExited(MouseEvent e) {
ImageIcon icon = new ImageIcon("image\\play.png");
this.jbPlay.setIcon(icon);
}
@Override
public void mousePressed(MouseEvent e) {
ImageIcon icon = new ImageIcon("image\\play_pressed.png");
this.jbPlay.setIcon(icon);
}
@Override
public void mouseReleased(MouseEvent e) {
ImageIcon icon = new ImageIcon("image\\play.png");
this.jbPlay.setIcon(icon);
}

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