我一直在开发音频播放器小程序，但在使其在网络浏览器中运行时遇到问题。它在 Eclipse 中的小程序查看器中完美运行，但当我在 Google Chrome 中尝试时它不起作用。我什至尝试了 eclipse 生成的小程序文件，但它也不起作用，可能与 eclipse 运行它的方式有关。
这是html文件，但不允许访问mp3文件，或我制作的特殊字体:
<html>
<meta http-equiv="Content-Type" content="text/html; charset=MacRoman"/>
<body>
<applet code="DOSPlayer.class" archive="DOSPlayer.jar, basicplayer3.0.jar, commons-logging-1.1.1.jar, mp3spi1.9.5.jar, tritonus_share-0.3.6.jar, jl1.0.1.jar" width="450" height="350" >
</applet>
</body>
</html>
我收到的错误是因为由于访问权限而无法访问文件:
java.security.AccessControlException: access denied (java.io.FilePermission fonts\DOSFont.ttf read)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkRead(Unknown Source)
at java.io.FileInputStream.<init>(Unknown Source)
at DOSPlayer.initFont(DOSPlayer.java:398)
at DOSPlayer.<init>(DOSPlayer.java:413)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$12.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
java.lang.reflect.InvocationTargetException
at com.sun.deploy.util.DeployAWTUtil.invokeAndWait(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.runOnEDT(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.security.AccessControlException: access denied (java.io.FilePermission mp3 read)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkRead(Unknown Source)
at java.io.File.list(Unknown Source)
at java.io.File.listFiles(Unknown Source)
at DOSPlayer.getFiles(DOSPlayer.java:259)
at DOSPlayer.<init>(DOSPlayer.java:415)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$12.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Exception: java.lang.reflect.InvocationTargetException
我知道错误来自这两个代码片段:
//path is "mp3/"
public String[] getFiles(String path) {
String[] songs = new String[501];
String files;
File folder = new File(path);
File[] listOfFiles = folder.listFiles();
//gets all mp3 files within mp3 folder
try {
for (int i = 0; i < listOfFiles.length; i++) {
if (listOfFiles[i].isFile())
{
files = listOfFiles[i].getName();
if (files.endsWith(".mp3")) {
songs[songNum] = files;
songNum++;
playableSongs++;
}
}
}
} catch (Exception e) {
System.out.println("Error Here");
e.printStackTrace();
return null;
}
return songs;
}
/////////////////////////////////
public void initFont() {
try {
//URL fontUrl = new URL("fonts/DOSFont.ttf");
File file = new File("fonts/DOSFont.ttf"); // where ever it is from
FileInputStream fontPath = new FileInputStream(file);
dosFont = Font.createFont(Font.TRUETYPE_FONT, fontPath);//fontUrl.openStream());
dosFont = dosFont.deriveFont(Font.PLAIN,19);
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
ge.registerFont(dosFont);
font = true;
} catch(Exception e) {
e.printStackTrace();
font = false;
}
}
我已经尝试签署该小程序，但这不起作用，它授予从网页查看该小程序的人访问文件的权限。我还尝试编辑策略文件，但无法使其工作，但它仍然是一个选项。
我在这个问题上遇到了几个小时的麻烦，不知道该怎么办，任何帮助将不胜感激。
最佳答案
这些资源(尤其是字体)实际上是“应用程序资源”，可以添加到 Jar 中并添加到小程序的运行时类路径中。如果不在存档中，则应将它们添加到服务器上的公共(public)位置(可以直接从浏览器访问它们)。
一旦放入 Jar 或服务器上，就可以通过 URL 访问它们。如果未嵌入 Jar 中，则 URL 可以形成为代码或文档库的相对路径。如果它们位于 Jar 中，请使用以下内容获取 URL:
URL urlToFont = this.getClass().getResource("/path/in/jar/to/the.ttf");
I also tried editing the policy file, and i can't get that to work, but it can still be an option.
不，不能。策略文件适用于非常有限的范围，公开部署的小程序不是其中之一。
<小时/>简单评论一下..
File[] listOfFiles = folder.listFiles();
这需要重新考虑。如果没有服务器的帮助，小程序无法获取服务器上的文件列表。要定义一组文件，小程序通常会有一个接受路径/名称的参数。
关于java - 小程序文件访问，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/11852643/