标签：images systemv templates txt rail 桌面 create ram java
JFileChooser文件选择器是Swing中经常用到的一个控件。它的使用主要包含以下几个参数：
1.当前路径。也就是它第一次打开时所在的路径，许多软件喜欢设置为桌面。
2.文件过滤器。通过设置文件过滤器，只有特定类型的文件是可见的，比如文本，音频，等。
3.选择模式。包含三种情况：仅文件, 仅目录, 文件或目录。
4.是否允许多选。
JFileChooser的参数当然不止以上4种，它还有很多高级选项，比如你可以对文件的显示图标进行定制等，由于不经常用，这里不再介绍。
有2个地方要注意：
1.文件过滤器建议使用FileNameExtensionFilter，它是FileFilter的子类，以非常方便的方法实现了过滤器。用法见代码。
2.getSelectedFiles()方法，它只在isMultiSelectionEnable()方法返回true是有效。也就是说，如果你不允许多选，则只能使用getSelectedFile()方法，否则只能得到一个空的文件列表。
下面通过一个demo来展示它的基本用法。
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package org.javacore.swing.JfileChooser; import java.io.File; import javax.swing.JFileChooser; import javax.swing.JOptionPane; import javax.swing.filechooser.FileNameExtensionFilter; import javax.swing.filechooser.FileSystemView; /** * * @author pzy */ public class JFileChooserFrame extends javax.swing.JFrame { /** * Creates new form JFileChooserFrame */ public JFileChooserFrame() { initComponents(); } /** * This method is called from within the constructor to initialize the form. * WARNING: Do NOT modify this code. The content of this method is always * regenerated by the Form Editor. */ @SuppressWarnings("unchecked") // <editor-fold defaultstate="collapsed" desc="Generated Code"> private void initComponents() { fileFilterisBG = new javax.swing.ButtonGroup(); isMultiSelectBG = new javax.swing.ButtonGroup(); jPanel1 = new javax.swing.JPanel(); text_rb = new javax.swing.JRadioButton(); video_rb = new javax.swing.JRadioButton(); audio_rb = new javax.swing.JRadioButton(); all_rb = new javax.swing.JRadioButton(); jPanel2 = new javax.swing.JPanel(); jComboBox1 = new javax.swing.JComboBox(); multiSelect_rb = new javax.swing.JRadioButton(); singleSelect_rb = new javax.swing.JRadioButton(); jPanel3 = new javax.swing.JPanel(); jButton1 = new javax.swing.JButton(); setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); setLocationByPlatform(true); jPanel1.setBorder(javax.swing.BorderFactory.createTitledBorder("文件类型")); fileFilterisBG.add(text_rb); text_rb.setText("文本"); fileFilterisBG.add(video_rb); video_rb.setText("视频"); fileFilterisBG.add(audio_rb); audio_rb.setText("音频"); fileFilterisBG.add(all_rb); all_rb.setSelected(true); all_rb.setText("所有"); javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1); jPanel1.setLayout(jPanel1Layout); jPanel1Layout.setHorizontalGroup( jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup() .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addComponent(text_rb) .addGap(29, 29, 29) .addComponent(video_rb) .addGap(35, 35, 35) .addComponent(audio_rb) .addGap(39, 39, 39) .addComponent(all_rb) .addGap(32, 32, 32)) ); jPanel1Layout.setVerticalGroup( jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel1Layout.createSequentialGroup() .addContainerGap() .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(video_rb) .addComponent(text_rb) .addComponent(audio_rb) .addComponent(all_rb)) .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) ); jPanel2.setBorder(javax.swing.BorderFactory.createTitledBorder("选择模式")); jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "仅文件", "仅目录", "文件或目录" })); jComboBox1.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { jComboBox1ActionPerformed(evt); } }); isMultiSelectBG.add(multiSelect_rb); multiSelect_rb.setText("可多选"); isMultiSelectBG.add(singleSelect_rb); singleSelect_rb.setSelected(true); singleSelect_rb.setText("不可多选"); javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2); jPanel2.setLayout(jPanel2Layout); jPanel2Layout.setHorizontalGroup( jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel2Layout.createSequentialGroup() .addContainerGap() .addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, 144, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(18, 18, 18) .addComponent(multiSelect_rb, javax.swing.GroupLayout.PREFERRED_SIZE, 82, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(18, 18, 18) .addComponent(singleSelect_rb, javax.swing.GroupLayout.PREFERRED_SIZE, 82, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(14, Short.MAX_VALUE)) ); jPanel2Layout.setVerticalGroup( jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel2Layout.createSequentialGroup() .addContainerGap() .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(multiSelect_rb) .addComponent(singleSelect_rb)) .addContainerGap(16, Short.MAX_VALUE)) ); jButton1.setText("开始"); jButton1.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { jButton1ActionPerformed(evt); } }); javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3); jPanel3.setLayout(jPanel3Layout); jPanel3Layout.setHorizontalGroup( jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel3Layout.createSequentialGroup() .addGap(117, 117, 117) .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 139, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) ); jPanel3Layout.setVerticalGroup( jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel3Layout.createSequentialGroup() .addGap(26, 26, 26) .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 32, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(19, Short.MAX_VALUE)) ); javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane()); getContentPane().setLayout(layout); layout.setHorizontalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addContainerGap() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addGroup(layout.createSequentialGroup() .addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addGap(84, 84, 84))) .addContainerGap()) ); layout.setVerticalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(8, 8, 8) .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(18, 18, 18) .addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(18, 18, 18) .addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) ); pack(); }// </editor-fold> private void jComboBox1ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: String itemString = jComboBox1.getSelectedItem().toString(); if ("仅文件".equals(itemString)) { fileSelectionMode = JFileChooser.FILES_ONLY; } else if ("仅目录".equals(itemString)) { fileSelectionMode = JFileChooser.DIRECTORIES_ONLY; } else if ("文件或目录".equals(itemString)) { fileSelectionMode = JFileChooser.FILES_AND_DIRECTORIES; } } private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: fileChooser = new JFileChooser(); //初始化当前路径 FileSystemView fsv = FileSystemView.getFileSystemView(); File homeFile =fsv.getHomeDirectory(); //这便是读取桌面路径的方法了 fileChooser.setCurrentDirectory(homeFile); //初始化文件过滤器 if (text_rb.isSelected()) { filter = new FileNameExtensionFilter("文本文件", "log", "txt"); fileChooser.setFileFilter(filter); } if (video_rb.isSelected()) { filter = new FileNameExtensionFilter("视频文件", "mp4", "mkv"); fileChooser.setFileFilter(filter); } if (audio_rb.isSelected()) { filter = new FileNameExtensionFilter("音频文件", "mp3", "wma"); fileChooser.setFileFilter(filter); } //初始化选择模式 fileChooser.setFileSelectionMode(fileSelectionMode); //是否允许多选 if (multiSelect_rb.isSelected()) { fileChooser.setMultiSelectionEnabled(true); } else if(singleSelect_rb.isSelected()) { fileChooser.setMultiSelectionEnabled(false); } //打开文件选择器 int i = fileChooser.showDialog(this, "选择"); if(i == JFileChooser.APPROVE_OPTION){ StringBuilder sb; if(fileChooser.isMultiSelectionEnabled()){ sb = new StringBuilder("您选择了以下文件："); File [] files = fileChooser.getSelectedFiles(); for (File file : files) { sb.append("\n"); sb.append(file.getName()); } } else{ File file = fileChooser.getSelectedFile(); sb = new StringBuilder("您选择的文件是："); sb.append("\n"); sb.append(file.getName()); } JOptionPane.showMessageDialog(this, sb); } } /** * @param args the command line arguments */ public static void main(String args[]) { /* Set the Nimbus look and feel */ //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) "> /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel. * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html */ try { for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) { if ("Nimbus".equals(info.getName())) { javax.swing.UIManager.setLookAndFeel(info.getClassName()); break; } } } catch (ClassNotFoundException ex) { java.util.logging.Logger.getLogger(JFileChooserFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (InstantiationException ex) { java.util.logging.Logger.getLogger(JFileChooserFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (IllegalAccessException ex) { java.util.logging.Logger.getLogger(JFileChooserFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (javax.swing.UnsupportedLookAndFeelException ex) { java.util.logging.Logger.getLogger(JFileChooserFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } //</editor-fold> /* Create and display the form */ java.awt.EventQueue.invokeLater(new Runnable() { public void run() { new JFileChooserFrame().setVisible(true); } }); } private JFileChooser fileChooser; private FileNameExtensionFilter filter; private int fileSelectionMode = JFileChooser.FILES_ONLY; // Variables declaration - do not modify private javax.swing.JRadioButton all_rb; private javax.swing.JRadioButton audio_rb; private javax.swing.ButtonGroup fileFilterisBG; private javax.swing.ButtonGroup isMultiSelectBG; private javax.swing.JButton jButton1; private javax.swing.JComboBox jComboBox1; private javax.swing.JPanel jPanel1; private javax.swing.JPanel jPanel2; private javax.swing.JPanel jPanel3; private javax.swing.JRadioButton multiSelect_rb; private javax.swing.JRadioButton singleSelect_rb; private javax.swing.JRadioButton text_rb; private javax.swing.JRadioButton video_rb; // End of variables declaration }
运行效果如下：
标签：images systemv templates txt rail 桌面 create ram java
原文地址：http://www.cnblogs.com/pzy4447/p/6095452.html
