获取一个SecurityException：权限在java中被拒绝 [英] Getting a SecurityException: Permission denied in java
问题描述
我收到 java.lang.SecurityException异常：权限被拒绝：文件：////Videos/public/scripts/screenshot.jar 当我尝试使用小程序。
下面是小程序code：
＆LT;小程序code =屏幕截图档案=文件：////Videos/public/scripts/screenshot.jarWIDTH =100px的HEIGHT = 100px的＆GT;
＆LT; /小程序＆GT;
如何解决呢，什么问题，甚至手段？
编辑：
从我看到我需要签名Applet。可能有人解释如何以及为什么这样做？提供的网站确实做得不好解释它，因为它甚至不解决，我嵌入到我的网站这个事实，并希望每一个客户端来使用它，而不必签署任何东西。只需点击运行。
EDIT2：
在应用程序本身的code：
/ *
通过Bavo Bruylandt（Http://www.realapplets.com）* ///现在inevidable的Hello World的例子:)//告诉编译器在哪里可以找到您要使用的方法。
//当你创建一个小程序所需
导入的java.applet。*;
//需要画上屏幕
进口java.awt中的*。
//一个小程序的启动 - 的HelloWorld将是可执行的类
//扩展小程序意味着你将建立code对标准的Applet类
公共类截图扩展的Applet
{//将当小程序开始自动调用的方法
公共无效的init（）
{
//这是必需的，但并不需要什么。
}
//此方法被当小程序被终止叫
//当用户进入到另一个页面或退出浏览器。
公共无效停止（）
{
//现在需要在这里没有动作。
}
//你有标准的方法，用油漆在屏幕上的东西
//这将覆盖空Applet的方法，你不能把它称为显示器为例。 公共无效漆（图形G）
{
//方法在屏幕上绘制文本
//串首先，则x和y坐标。
g.drawString（嘿嘿嘿，20,20）;
g.drawString（Hellooow世界，20,40）; }}
这一切都取决于你有什么小程序试图做的，它是访问，例如文件系统。它是一个签名的applet或不？小程序在一个特殊的沙箱默认情况下，有限的权限运行。
你将不得不签出更多的信息上的Applet的安全性，对于初学者看看到InformIT的文章在这里：的 http://www.informit.com/articles/article.aspx?p=433382&seqNum=2
编辑：
尝试添加一个策略文件如：
/ *自动生成于星期二2002年4月16日17点20分59秒EDT * /
/ * DO NOT EDIT * / 补助{
权限java.security.AllPermission;
};
命名如。 java.policy.applet并将其放置在你的类路径中。看看这个问题，在这里对政策文件：在哪里放置Java applet的政策文件？
I am getting the java.lang.SecurityException: Permission denied: file:////Videos/public/scripts/screenshot.jar when I try to use an applet.
Here is the applet code:
<applet code="Screenshot" archive="file:////Videos/public/scripts/screenshot.jar" width="100px" height="100px">
</applet>
How do I fix it and what the problem even means?
EDIT:
From what I see I need to sign the applet. Could some one explain how and why this is done? The site provided does a bad job explaining it because it doesn't even address the fact that I am embedding this into my site and want every client to use it and not have to sign anything. Just click run.
EDIT2:
The code of the app itself:
/*
By Bavo Bruylandt (Http://www.realapplets.com")
*/
// and now The inevidable "Hello World" example :)
// tell the compiler where to find the methods you will use.
// required when you create an applet
import java.applet.*;
// required to paint on screen
import java.awt.*;
// the start of an applet - HelloWorld will be the executable class
// Extends applet means that you will build the code on the standard Applet class
public class Screenshot extends Applet
{
// The method that will be automatically called when the applet is started
public void init()
{
// It is required but does not need anything.
}
// This method gets called when the applet is terminated
// That's when the user goes to another page or exits the browser.
public void stop()
{
// no actions needed here now.
}
// The standard method that you have to use to paint things on screen
// This overrides the empty Applet method, you can't called it "display" for example.
public void paint(Graphics g)
{
//method to draw text on screen
// String first, then x and y coordinate.
g.drawString("Hey hey hey",20,20);
g.drawString("Hellooow World",20,40);
}
}
It all depends on what is your applet trying to do, is it accessing the filesystem for example. Is it a signed applet or not? Applets run in a special sandbox by default with limited permissions. You would have to check out more info on Applet security, for starters have a look into Informit article here: http://www.informit.com/articles/article.aspx?p=433382&seqNum=2
EDIT:
Try to add a policy file eg.
/* AUTOMATICALLY GENERATED ON Tue Apr 16 17:20:59 EDT 2002*/
/* DO NOT EDIT */
grant {
permission java.security.AllPermission;
};
named eg. java.policy.applet and place it on your classpath. Have a look at this question here about the policy files: Where to place java applet policy file?
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