我正在尝试从小程序编写示例文件，但无法正常工作。下面是代码。
小程序
public class PasteImageApplet extends JApplet {
Clipboard clipboard;
Toolkit toolkit;
JLabel lbl;
public String getClipboardImageURL(String server) {
lbl.setText("pasting image");
String url = "";
try {
DataFlavor dataFlavor = DataFlavor.imageFlavor;
System.out.println(dataFlavor.getDefaultRepresentationClass());
Object object = null;
try {
object = clipboard.getContents(null)
.getTransferData(dataFlavor);
JOptionPane.showMessageDialog(null,"Image found.");
try
{
Writer output = null;
String text = "Test Write File";
File file = new File("write.txt");
output = new BufferedWriter(new FileWriter(file));
output.write(text);
output.close();
}
catch(Exception ex)
{
JOptionPane.showMessageDialog(null,"Error writing file"+ex);
return "" ;
}
//return "";
} catch (Exception e) {
JOptionPane.showMessageDialog(null, "No image found.");
return "";
}
} catch (Exception e) {
JOptionPane.showMessageDialog(null, "Error."+e);
return "";
}
return url;
}
public void init() {
lbl = new JLabel("");
lbl.setText("applet started");
add(lbl);
toolkit = Toolkit.getDefaultToolkit();
clipboard = toolkit.getSystemClipboard();
}
}
HTML
<html>
<head>
<title>Clipboard image demo</title>
<script type="text/javascript">
function loadApplet() {
// Deferred load to display text first
document.getElementById("applet").innerHTML = '<object id="paste-image" classid="java:PasteImageApplet.class" type="application/x-java-applet" archive="tst.jar" width="1" height="1"></object>';
}
function getImage() {
obj = document.getElementById('paste-image');
postTo = "http://localhost/PasteImageApplet/PasteImageApplet/Web/shoot.php"; // Change this to your URL
image = obj.getClipboardImageURL(postTo);
if (image) {
url = "shots/" + image;
document.getElementById("target").src = url;
document.getElementById("url").value = document.getElementById("target").src; // to get full path, hack, I know ;)
document.getElementById("container").style.display = "";
}
}
</script>
<body onload="loadApplet();">
<p>
Copy some image data to your clipboard, accept the applet (it only accesses the clipboard) and click the button :-)
<a href="http://lassebunk.dk/2009/07/19/using-the-clipboard-to-post-images/">See a blog post about this demo</a>
</p>
<p>
<div id="applet"></div>
<input type="button" value="Paste it!" onclick="getImage();">
</p>
<div id="container" style="display: none;">
<input type="text" id="url" style="width: 700px;"><br />
<iframe id="target" width="700" height="400"></iframe>
</div>
</body>
</html>
我也没有收到任何错误。请指教。
最佳答案
这是因为小程序存在于自己的沙箱中，它们需要特殊权限才能执行某些操作，例如读取或写入客户端计算机的磁盘。请记住，小程序在客户端计算机的上下文中执行，它们是访客，需要遵守内部规则
查看What Applets can and cannot do了解更多详情
关于java - 小程序 - 无法写入文件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/17779024/