swing文件选取器 例子 (4种读写文件方式-和图片的读写方法)

package capture.selector; import java.awt.Image; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.image.BufferedImage; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import javax.swing.JButton; import javax.swing.JFileChooser; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.SwingUtilities; import javax.swing.UIManager; import javax.swing.WindowConstants; import org.dyno.visual.swing.layouts.Constraints; import org.dyno.visual.swing.layouts.GroupLayout; import org.dyno.visual.swing.layouts.Leading; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; //VS4E -- DO NOT REMOVE THIS LINE! /** * @author lushuaiyin * @date 2011-10-18 */ public class Settest extends JFrame { File targetFile; String message=""; private static final long serialVersionUID = 1L; private JTextArea jTextArea0; private JScrollPane jScrollPane0; private JButton jButton0; private JLabel jLabel1; private JButton jButton1; private JButton jButton2; private static final String PREFERRED_LOOK_AND_FEEL = "javax.swing.plaf.metal.MetalLookAndFeel"; public Settest() { initComponents(); } private void initComponents() { setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE); setLayout(new GroupLayout()); add(getJLabel1(), new Constraints(new Leading(12, 12, 12), new Leading(59, 22, 10, 10))); add(getJButton1(), new Constraints(new Leading(52, 10, 10), new Leading(142, 10, 10))); add(getJButton0(), new Constraints(new Leading(218, 10, 10), new Leading(142, 12, 12))); add(getJScrollPane0(), new Constraints(new Leading(106, 334, 10, 10), new Leading(42, 51, 10, 10))); add(getJButton2(), new Constraints(new Leading(329, 10, 10), new Leading(142, 12, 12))); setSize(501, 240); } private JButton getJButton2() { if (jButton2 == null) { jButton2 = new JButton(); jButton2.setText("（图片时）另存为"); jButton2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { try { jButton2ActionActionPerformed(event); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }); } return jButton2; } private JButton getJButton1() { if (jButton1 == null) { jButton1 = new JButton(); jButton1.setText("选择读取文件"); jButton1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { jButton1ActionActionPerformed(event); } }); } return jButton1; } private JLabel getJLabel1() { if (jLabel1 == null) { jLabel1 = new JLabel(); jLabel1.setText("源文件路径"); } return jLabel1; } private JButton getJButton0() { if (jButton0 == null) { jButton0 = new JButton(); jButton0.setText("另存为"); jButton0.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { try { jButton0ActionActionPerformed(event); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }); } return jButton0; } private JScrollPane getJScrollPane0() { if (jScrollPane0 == null) { jScrollPane0 = new JScrollPane(); jScrollPane0.setViewportView(getJTextArea0()); } return jScrollPane0; } private JTextArea getJTextArea0() { if (jTextArea0 == null) { jTextArea0 = new JTextArea(); jTextArea0.setText("jTextArea0"); } return jTextArea0; } private static void installLnF() { try { String lnfClassname = PREFERRED_LOOK_AND_FEEL; if (lnfClassname == null) lnfClassname = UIManager.getCrossPlatformLookAndFeelClassName(); UIManager.setLookAndFeel(lnfClassname); } catch (Exception e) { System.err.println("Cannot install " + PREFERRED_LOOK_AND_FEEL + " on this platform:" + e.getMessage()); } } /** * Main entry of the class. * Note: This class is only created so that you can easily preview the result at runtime. * It is not expected to be managed by the designer. * You can modify it as you like. */ public static void main(String[] args) { installLnF(); SwingUtilities.invokeLater(new Runnable() { @Override public void run() { Settest frame = new Settest(); frame.setDefaultCloseOperation(Settest.EXIT_ON_CLOSE); frame.setTitle("Settest"); frame.getContentPane().setPreferredSize(frame.getSize()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } //读取文件 private void jButton1ActionActionPerformed(ActionEvent event) { JFileChooser dlg = new JFileChooser(); /** * 设置对话框类型,其打开方法也要对应正确，打开方法控制显示界面 */ dlg.setDialogType(JFileChooser.OPEN_DIALOG); //设定好类型后和dlg.showOpenDialog(null)方法配套使用才会显示保存对话框 // dlg.setDialogType(JFileChooser.SAVE_DIALOG); //设定好类型后和dlg.showDialog(null, "haha")方法配套使用，并且第一个按钮显示为第二个参数"haha". // dlg.setDialogType(JFileChooser.CUSTOM_DIALOG); //第一个参数父组件，第2 个参数是第一个按钮的名字（不再是打开或保存了） // dlg.showDialog(null, "haha"); dlg.showOpenDialog(null); // dlg.showSaveDialog(null); File file=dlg.getSelectedFile(); if(file==null){ this.message="没有选取文件"; }else{ //得到这个文件后，想干嘛干嘛 System.out.println("getAbsolutePath--"+file.getAbsolutePath()); System.out.println("getName--"+file.getName()); System.out.println("isFile--"+file.isFile()); System.out.println("isDirectory--"+file.isDirectory()); System.out.println("getPath--"+file.getPath()); System.out.println("getParent--"+file.getParent()); this.targetFile=file; this.message=file.getPath().toString(); } jTextArea0.setText(this.message); } //另存为 private void jButton0ActionActionPerformed(ActionEvent event) throws IOException { FileInputStream fis=null; InputStreamReader isr=null; BufferedReader br=null; FileOutputStream fos=null; OutputStreamWriter osw=null; BufferedWriter bw=null; FileReader fr=null; FileWriter fw=null; if(targetFile==null){ System.out.println("源文件为空，请先选择要保存的文件！"); JOptionPane.showMessageDialog(null, "源文件为空，请先选择要保存的文件！"); }else{ JFileChooser dlg = new JFileChooser(); dlg.setDialogType(JFileChooser.SAVE_DIALOG); dlg.showSaveDialog(null); File getNewFile=dlg.getSelectedFile(); String getNewPath=getNewFile.getPath(); String getNewName=getNewFile.getPath(); String getNewParent=getNewFile.getParent(); System.out.println("getNewPath::"+getNewPath); System.out.println("getNewName::"+getNewName); System.out.println("getNewParent::"+getNewParent); //写入新文件 try { //读源文件 fis = new FileInputStream(this.targetFile); isr = new InputStreamReader(fis); br = new BufferedReader(isr); fr=new FileReader(this.targetFile); //写新文件 File newFile=new File(getNewPath); if(!newFile.exists()){ newFile.createNewFile(); } fos=new FileOutputStream(newFile); osw=new OutputStreamWriter(fos); bw=new BufferedWriter(osw); fw = new FileWriter(newFile); //下面提供了4中读写文件方法，都已通过测试。 //用BufferedReader，BufferedWriter 实验成功,注意读一行后加换行符！ // String ss=null; // while((ss=br.readLine())!=null){ // bw.write(ss+"\n"); // bw.flush(); // } //用InputStreamReader，OutputStreamWriter 实验成功 // char[] buf=new char[2048]; // int num=0; // while((num=isr.read(buf))!=(-1)) // { //是否读完文件 // osw.write(buf, 0, num);//把文件数据写出网络缓冲区 // osw.flush();//刷新缓冲区把数据写往客户端 // } //用FileReader,FileWriter操作，试验成功 // char[] cbuf=new char[1024]; // int nn=0; // while((nn=fr.read(cbuf))!=-1){ // bw.write(cbuf,0,nn); // bw.flush(); // } //用FileInputStream,FileOutputStream操作，试验成功 byte[] b = new byte[512]; int n; while((n = fis.read(b))!=-1){ fos.write(n); } } catch (FileNotFoundException e) { e.printStackTrace(); }finally{ if(bw!=null){ bw.close();} if(osw!=null){ osw.close();} if(fos!=null){ fos.close();} if(br!=null){ br.close();} if(isr!=null){ isr.close();} if(fr!=null){ fr.close();} if(fw!=null){ fw.close();} } JOptionPane.showMessageDialog(null, "保存成功！"); } } //图片时另存为 private void jButton2ActionActionPerformed(ActionEvent event) throws IOException { FileInputStream fis2=null; InputStreamReader isr2=null; BufferedReader br2=null; FileOutputStream fos2=null; OutputStreamWriter osw2=null; BufferedWriter bw2=null; FileReader fr2=null; FileWriter fw2=null; JFileChooser dlg = new JFileChooser(); dlg.setDialogType(JFileChooser.SAVE_DIALOG); dlg.showSaveDialog(null); File getNewFile=dlg.getSelectedFile(); String getNewPath=getNewFile.getPath(); String getNewName=getNewFile.getPath(); String getNewParent=getNewFile.getParent(); System.out.println("getNewPath::"+getNewPath); System.out.println("getNewName::"+getNewName); System.out.println("getNewParent::"+getNewParent); //写入新文件 try { //读源文件 fis2 = new FileInputStream(this.targetFile); isr2 = new InputStreamReader(fis2); br2 = new BufferedReader(isr2); Image src = javax.imageio.ImageIO.read(this.targetFile); //构造Image对象 int wideth=src.getWidth(null); //得到源图宽 int height=src.getHeight(null); //得到源图长 fr2=new FileReader(this.targetFile); //写新文件 File newFile=new File(getNewPath); if(!newFile.exists()){ newFile.createNewFile(); } fos2=new FileOutputStream(newFile); osw2=new OutputStreamWriter(fos2); bw2=new BufferedWriter(osw2); fw2 = new FileWriter(newFile); //用Graphics操作，试验成功 BufferedImage tag = new BufferedImage(wideth,height,BufferedImage.TYPE_INT_RGB); tag.getGraphics().drawImage(src,0,0,wideth,height,null); fos2=new FileOutputStream(getNewPath); //输出到文件流 JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(fos2); encoder.encode(tag); //JPEG编码 } catch (FileNotFoundException e) { e.printStackTrace(); }finally{ if(bw2!=null){ bw2.close();} if(osw2!=null){ osw2.close();} if(fos2!=null){ fos2.close();} if(br2!=null){ br2.close();} if(isr2!=null){ isr2.close();} if(fr2!=null){ fr2.close();} if(fw2!=null){ fw2.close();} } JOptionPane.showMessageDialog(null, "保存成功！"); } }