所以这就是事情，我试图为一个网页游戏做一个小程序来产生“自定义”头像，这个头像是为一个国家的军队提供的，所以头像的选择取决于形象用户，图片上的边框也代表该用户所属的四边形。
所以我的计划是让他们从他们计算机中的一个文件中进行选择，然后他们选择他们所属的小队。在此之后，他们将看到图片的预览，他们可以将其保存到他们的计算机中，以便以后在游戏中使用。
我知道您可以在组件的背景上使用 Graphic 或 Graphic2D 绘制图像，但是当我想将其保存到文件时，我该怎么做？
【问题讨论】：
标签： java image swing applet save
使用JFileChooser#showSaveDialog() 要求用户选择/指定要保存的文件，然后使用ImageIO#write() 将BufferedImage 写入文件。
JFileChooser fileChooser = new JFileChooser();
if (fileChooser.showSaveDialog(null) == JFileChooser.APPROVE_OPTION) {
ImageIO.write(bufferedImage, "JPEG", fileChooser.getSelectedFile());
} else {
// User pressed cancel.
}
但是需要对小程序进行签名以避免最终用户被安全警告吓到。
【讨论】：
使用插件 2 (PI2 - 1.6.0_10+) 架构 JRE 部署的小程序不需要数字代码签名。在 PI2 JRE 中，嵌入式小程序可以访问通常仅适用于 Java Web Start 应用程序的所有服务。
此小程序感兴趣的服务是FileOpenService (FOS) 和PersistenceService (PS)。 FOS 可用于允许用户导航到文件（或者更确切地说 - 文件内容）对象并从中获取流。一旦用户对裁剪后的图像感到满意，将其保存到 PS 以供以后检索（使用 ImageIO，如前所述）。
【讨论】：
这是你可以保存内容的记事本代码，如果你将文本转换为图像，请尝试通过它
/*Arpana*/
mport 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);
}
}
【讨论】：
我想我倾向于在同一页面上将 Java 与 Javascript 进行交互，并提供一个“导出”按钮，将其在本地序列化为 PNG，并将其作为下载提供（应该可以在用户不需要的情况下全部完成）刷新页面或乱七八糟）。上一个问题有一些有趣的cmets：Java applet - saving an image in a png format
【讨论】：
我在这篇文章上方发布的记事本程序提供了任何类型的加载图像，也可以保存任何类型的图像....
所以您可以参考相同的代码来加载图像并保存图像
【讨论】：