Question

我正在尝试执行此程序， http://java.sun.com/developer/technicalArticles/ThirdParty/WebCrawler/WebCrawler.java 在我推荐此页面后，程序编译没有任何错误， http://www.velocityreviews.com/forums/t146972-web-crawler.html

但是在使用“appletviewer WebCrawler.html”命令执行时，我得到了这个例外..

Exception in thread "Thread-4" 
java.security.AccessControlException:access denied(java.net.SocketPermission java.sun.com:80 connect,resolve)

at java.security.AccessControlContext.checkPermission(AccessControlContext.java:323)

at java.security.AccessController.checkPermission(AccessController.java:546)

at java.lang.SecurityManager.checkPermission(SecurityManager.java:532)

at java.lang.SecurityManager.checkConnect(SecurityManager.java:1034)

at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)

at sun.net.www.http.HttpClient.<init>(HttpClient.java:233)

at sun.net.www.http.HttpClient.New(HttpClient.java:306)

at sun.net.www.http.HttpClient.New(HttpClient.java:323)

at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:860)

at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:801)

at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:726)

at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1049)

at java.net.URL.openStream(URL.java:1010)

at WebCrawler.robotSafe(WebCrawler.java:139)

at WebCrawler.run(WebCrawler.java:235)

at java.lang.Thread.run(Thread.java:619)

我如何让它发挥作用。？

Answer 1

默认情况下，applet只能连接到它所在的同一服务器+端口。您可以执行以下操作之一：

将应用转换为应用，取消安全限制
使用受信任/签名的小程序

您还可以查看为applet配置交叉域，请参阅：

http://weblogs.java.net/blog/2008/05/28/java-doodle-crossdomainxml-support

Answer 2

自行签署applet（你可以免费做）非常简单。如果您不对applet进行签名，则只能获得最低限度的安全访问权限，并且不会授予对套接字的访问权限。

简单的3步指南就在这里：

http://www.narendranaidu.com/2007/11/3-easy-steps-to-self-sign-applet-jar.html

或更深入的探索： http://java.sun.com/developer/onlineTraining/Programming/JDCBook/signed.html

Java安全访问控制异常

2 个答案: