Java学习笔记之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！");
	
	}

}