在Jetty中访问Web容器外部的文件

时间：2011-06-25 10:20:32

标签： web-services servlets java-ee gwt-rpc

我在Windows XP SP3中使用Eclipse 3.6来开发GWT应用程序。应用程序需要将包含驻留在服务器上的图形的文件夹的内容显示给客户端。此外，图形文件夹不在Web容器内，而是在硬盘中的另一个位置。 Eclispe使用Jetty HTTP服务器来运行Web应用程序。我在RemoteServiceServlet中使用以下代码段来测试文件访问权限并获取文本文件的内容。

File inputFile = new File("C:\\mytext.txt");
FileReader fin = new FileReader(inputFile);
char c[] = new char[(char)inputFile.length()];
int i;
i = fin.read(c);
s = new String(c);

不幸的是我收到错误，我不知道如何翻译它以纠正代码（或任何配置文件）。

Initializing AppEngine server
Unable to access http://appengine.google.com/api/updatecheck?runtime=java&release=1.5.1&timestamp=1308100600&api_versions=['1.0']
java.net.UnknownHostException: appengine.google.com
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at sun.net.NetworkClient.doConnect(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.http.HttpClient.openServer(Unknown Source)
    at sun.net.www.http.HttpClient.<init>(Unknown Source)
    at sun.net.www.http.HttpClient.New(Unknown Source)
    at sun.net.www.http.HttpClient.New(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at java.net.URL.openStream(Unknown Source)
    at com.google.appengine.tools.info.RemoteVersionFactory.getVersion(RemoteVersionFactory.java:76)
    at com.google.appengine.tools.info.UpdateCheck.checkForUpdates(UpdateCheck.java:99)
    at com.google.appengine.tools.info.UpdateCheck.doNagScreen(UpdateCheck.java:174)
    at com.google.appengine.tools.info.UpdateCheck.maybePrintNagScreen(UpdateCheck.java:142)
    at com.google.appengine.tools.development.gwt.AppEngineLauncher.maybePerformUpdateCheck(AppEngineLauncher.java:137)
    at com.google.appengine.tools.development.gwt.AppEngineLauncher.start(AppEngineLauncher.java:103)
    at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:500)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1055)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:804)
    at com.google.gwt.dev.DevMode.main(DevMode.java:309)
Logging to JettyLogger(null) via com.google.apphosting.utils.jetty.JettyLogger
Successfully processed C:\Documents and Settings\Giorgos\workspace\Zserver\war\WEB-INF/appengine-web.xml
Successfully processed C:\Documents and Settings\Giorgos\workspace\Zserver\war\WEB-INF/web.xml
The server is running at http://localhost:8888/
[ERROR] javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String mytest.client.GreetingService.greetServer(java.lang.String) throws java.lang.IllegalArgumentException' threw an unexpected exception: java.security.AccessControlException: access denied (java.io.FilePermission C:\mytext.txt read)
    at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:588)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
    at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
    at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:58)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:70)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:351)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.security.AccessControlException: access denied (java.io.FilePermission C:\mytext.txt read)
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkPermission(DevAppServerFactory.java:166)
    at java.lang.SecurityManager.checkRead(Unknown Source)
    at java.io.FileInputStream.<init>(Unknown Source)
    at java.io.FileReader.<init>(Unknown Source)
    at mytest.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:34)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:100)
    at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
    ... 34 more

1 个答案:

答案 0 :(得分：1)

有许多无关的问题：

  1. 鉴于问题中的堆栈跟踪，您似乎正在为Google App Engine开发应用程序。 GAE不允许访问文件系统，因此会得到AccessControlException。
  2. 文本文件不是图形文件。我不明白你想做什么。
  3. 第new char[(char)inputFile.length()];行是错误的。为什么要将文件的长度转换为char？
  4. read method并不保证会立即读取所有文件。它返回读取的字符数。您不应该忽略返回的值。阅读the tutorial about IO。
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