is there any way to save an image fro开发者_JS百科m a java applet
Been asked before:
Java applet - saving an image in a png format
or
Save an Image to a File in a Applet?
Please first search your question or at least check out the related questions as you type your question in. It's very helpful for finding other users with common issues.
Just try this notepad example which helps u to load images and save it also,
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Scanner;
import java.io.*;
public class Notepad extends JFrame implements ActionListener {
private TextArea textArea = new TextArea("", 0,0, TextArea.SCROLLBARS_VERTICAL_ONLY);
private MenuBar menuBar = new MenuBar(); // first, create a MenuBar item
private Menu file = new Menu(); // our File menu
// what's going in File? let's see...
private MenuItem openFile = new MenuItem(); // an open option
private MenuItem saveFile = new MenuItem(); // a save option
private MenuItem close = new MenuItem(); // and a close option!
public Notepad() {
this.setSize(500, 300); // set the initial size of the window
this.setTitle("Java Notepad Tutorial"); // set the title of the window
setDefaultCloseOperation(EXIT_ON_CLOSE); // set the default close operation (exit when it gets closed)
this.textArea.setFont(new Font("Century Gothic", Font.BOLD, 12)); // set a default font for the TextArea
// this is why we didn't have to worry about the size of the TextArea!
this.getContentPane().setLayout(new BorderLayout()); // the BorderLayout bit makes it fill it automatically
this.getContentPane().add(textArea);
// add our menu bar into the GUI
this.setMenuBar(this.menuBar);
this.menuBar.add(this.file); // we'll configure this later
// first off, the design of the menuBar itself. Pretty simple, all we need to do
// is add a couple of menus, which will be populated later on
this.file.setLabel("File");
// now it's time to work with the menu. I'm only going to add a basic File menu
// but you could add more!
// now we can start working on the content of the menu~ this
gets a little repetitive,
// so please bare with me!
// time for the repetitive stuff. let's add the "Open" option
this.openFile.setLabel("Open"); // set the label of the menu item
this.openFile.addActionListener(this);
// add an action listener (so we know when it's been clicked
this.openFile.setShortcut(new MenuShortcut(KeyEvent.VK_O, false));
// set a keyboard shortcut
this.file.add(this.openFile); // add it to the "File" menu
// and the save...
this.saveFile.setLabel("Save");
this.saveFile.addActionListener(this);
this.saveFile.setShortcut(new MenuShortcut(KeyEvent.VK_S, false));
this.file.add(this.saveFile);
// and finally, the close option
this.close.setLabel("Close");
// along with our "CTRL+F4" shortcut to close the window, we also have
// the default closer, as stated at the beginning of this tutorial.
// this means that we actually have TWO shortcuts to close:
// 1) the default close operation (example, Alt+F4 on Windows)
// 2) CTRL+F4, which we are about to define now:
(this one will appear in the label)
this.close.setShortcut(new MenuShortcut(KeyEvent.VK_F4, false));
this.close.addActionListener(this);
this.file.add(this.close);
}
public void actionPerformed (ActionEvent e) {
// if the source of the event was our "close" option
if (e.getSource() == this.close)
this.dispose(); // dispose all resources and close the application
// if the source was the "open" option
else if (e.getSource() == this.openFile) {
JFileChooser open = new JFileChooser();
// open up a file chooser (a dialog for the user to browse files to open)
int option = open.showOpenDialog(this);
// get the option that the user selected (approve or cancel)
// NOTE: because we are OPENing a file, we call showOpenDialog~
// if the user clicked OK, we have "APPROVE_OPTION"
// so we want to open the file
if (option == JFileChooser.APPROVE_OPTION) {
this.textArea.setText("");
// clear the TextArea before applying the file contents
try {
// create a scanner to read the file (getSelectedFile().getPath() will get the path to the file)
Scanner scan = new Scanner(new FileReader(open.getSelectedFile().getPath()));
while (scan.hasNext()) // while there's still something to read
this.textArea.append(scan.nextLine() + "\n"); // append the line to the TextArea
} catch (Exception ex) { // catch any exceptions, and...
// ...write to the debug console
System.out.println(ex.getMessage());
}
}
}
// and lastly, if the source of the event was the "save" option
else if (e.getSource() == this.saveFile) {
JFileChooser save = new JFileChooser(); // again, open a file chooser
int option = save.showSaveDialog(this); // similar to the open file, only this time we call
// showSaveDialog instead of showOpenDialog
// if the user clicked OK (and not cancel)
if (option == JFileChooser.APPROVE_OPTION) {
try {
// create a buffered writer to write to a file
BufferedWriter out = new BufferedWriter(new FileWriter(save.getSelectedFile().getPath()));
out.write(this.textArea.getText()); // write the contents of the TextArea to the file
out.close(); // close the file stream
} catch (Exception ex) { // again, catch any exceptions and...
// ...write to the debug console
System.out.println(ex.getMessage());
}
}
}
}
// the main method, for actually creating our notepad and setting it to visible.
public static void main(String args[]) {
Notepad app = new Notepad();
app.setVisible(true);
}
}
精彩评论