从小程序保存图像

Question

有什么方法可以从 java 小程序中保存图像

Answer 1

之前被问过：
Java applet - saving an image in a png format
或
Save an Image to a File in a Applet?

请先搜索您的问题，或者至少在您输入问题时查看相关问题。这对于查找其他有常见问题的用户非常有帮助。

Answer 2

试试这个记事本示例，它可以帮助您加载图像并保存它，

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);

}

}