Question

java中文字图片读取保存问题

我以下的代码只能保存和读取文字内容,无法读取图片信息,请帮忙修改一下代码,使之可以保存读取文字和图片,要求保留代码中的文件选择器.

//打开文件
public void jButton3_actionPerformed(ActionEvent e) {
String s;
int state = chooser.showOpenDialog(null);
File file = chooser.getSelectedFile();
if (file != null && state == JFileChooser.APPROVE_OPTION) {
try {
readfile = new FileInputStream(file);
jTextPane1.read(readfile, this);
setTitle(chooser.getSelectedFile().getName());
} catch (IOException e1) {
e1.printStackTrace();
}
}

}

//文件保存
public void jButton4_actionPerformed(ActionEvent e) {
JFileChooser fc = new JFileChooser();
int returnVal = fc.showSaveDialog(Face.this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
String savefile = fc.getSelectedFile().getPath();
if (savefile == null) {
return;
} else {
String docToSave = jTextPane1.getText();
if (docToSave != null) {
ObjectOutputStream fstrm = null;
BufferedOutputStream ostrm = null;
try {
fstrm = new ObjectOutputStream(new FileOutputStream(savefile));
ostrm = new BufferedOutputStream(fstrm);
byte[] bytes = null;
try {
bytes = docToSave.getBytes();
} catch (Exception e1) {
e1.printStackTrace();
}
ostrm.write(bytes);
} catch (IOException io) {
System.err.println("IOException: " +
io.getMessage());
} finally {
try {
ostrm.flush();
fstrm.close();
ostrm.close();
} catch (IOException ioe) {
System.err.println("IOException: " +
ioe.getMessage());
}
}
}
}
} else {
return;
}
}

Answer 1

如果你的文本区中不只包含图片信息，而且还包含文本信息，就不好保存了。下面的代码没有实现这个功能。它只是可以打开图片或文本文件。保存图片或文本文件。

import java.io.*;

import javax.swing.*;
import javax.swing.text.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;

public class ImageTest extends JFrame {
private JFileChooser chooser = new JFileChooser(".");
private FileInputStream readfile;
private JTextPane jTextPane1 = new JTextPane();
private JScrollPane jsp = new JScrollPane(jTextPane1);
private JMenuBar menuBar = new JMenuBar();
private JMenu fileMenu = new JMenu("File");
private JMenuItem open = new JMenuItem("open");
private JMenuItem save = new JMenuItem("save");

// 只有部分扩展名的文件是可以显示的。
private String s = "jpg,bmp,tga,vst,pcd,pct,gif,ai,fpx,img,cal,wi,png";
private ImageIcon icon;
private File file;

public ImageTest() {
this.setSize(800, 600);
this.setJMenuBar(menuBar);
menuBar.add(fileMenu);
fileMenu.add(open);
fileMenu.add(save);
this.add(jsp);
open.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jButton3_actionPerformed(evt);
}
});
save.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jButton4_actionPerformed(evt);
}
});
}

public static void main(String args[]) throws Exception {
ImageTest test = new ImageTest();
test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
test.setVisible(true);
}

public void jButton3_actionPerformed(ActionEvent e) {
int state = chooser.showOpenDialog(null);
file = chooser.getSelectedFile();
if (file != null && state == JFileChooser.APPROVE_OPTION) {
try {
String fileName = file.getName();
jTextPane1.setText(null);
if(s.indexOf(fileName.substring(fileName.lastIndexOf(".") + 1).toLowerCase()) != -1) {
icon = new ImageIcon(file.getAbsolutePath());
jTextPane1.insertIcon(icon);
} else {
readfile = new FileInputStream(file);
jTextPane1.read(readfile, file.getName());
}
setTitle(chooser.getSelectedFile().getName());
} catch (Exception e1) {
e1.printStackTrace();
}
}
}

//文件保存
public void jButton4_actionPerformed(ActionEvent e) {
JFileChooser fc = new JFileChooser();
int returnVal = fc.showSaveDialog(this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
String savefile = fc.getSelectedFile().getPath();
if (savefile == null) {
return;
} else {
if(icon != null) {
try {
FileOutputStream out = new FileOutputStream(savefile);
out.write(getBytesFromFile(file));
out.close();
} catch(Exception ex) {
}
} else {
String docToSave = jTextPane1.getText();
if (docToSave != null) {
ObjectOutputStream fstrm = null;
BufferedOutputStream ostrm = null;
try {
fstrm = new ObjectOutputStream(new FileOutputStream(savefile));
ostrm = new BufferedOutputStream(fstrm);
byte[] bytes = null;
try {
bytes = docToSave.getBytes();
} catch (Exception e1) {
e1.printStackTrace();
}
ostrm.write(bytes);
} catch (IOException io) {
System.err.println("IOException: " +
io.getMessage());
} finally {
try {
ostrm.flush();
fstrm.close();
ostrm.close();
} catch (IOException ioe) {
System.err.println("IOException: " +
ioe.getMessage());
}
}
}
}
}
} else {
return;
}
}

public static byte[] getBytesFromFile(File f) {
if (f == null) {
return null;
}
try {
FileInputStream stream = new FileInputStream(f);
ByteArrayOutputStream out = new ByteArrayOutputStream(1000);
byte[] b = new byte[1000];
int n;
while ((n = stream.read(b)) != -1)
out.write(b, 0, n);
stream.close();
out.close();
return out.toByteArray();
} catch (IOException e) {
}
return null;
}
}

Answer 2

用字节流去读写文件，不管是文字还是图片都可以的

Answer 3

你只要用字节流去读写文件，不管是文字还是图片都可以的，你这里应该是对的，所以，问题应该出在其它部分。

Answer 4

图片是2进制文件 是不是需要修改MIME类型? JSP文件上传的时候我们都要修改.这个不知道为什么.希望能抛砖引玉