错误的App Engine-

Question

when I deploy my application, no error appears, however when I access my application, the following error appears: 部署应用程序时，没有错误出现，但是当我访问应用程序时，出现以下错误：

Error: Server Error The server encountered an error and could not complete your request. 错误：服务器错误服务器遇到错误，无法完成您的请求。 Please try again in 30 seconds. 请在30秒后重试。

Erro Log on Google App Engine Admin:
Uncaught exception from servlet
java.lang.UnsupportedClassVersionError: org/apache/jsp/PessoaApplication_jsp : Unsupported major.minor version 52.0
    at com.google.appengine.runtime.Request.process-6a9f678c146455a7(Request.java)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:795)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
    at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:360)
    at org.mortbay.util.Loader.loadClass(Loader.java:91)
    at org.mortbay.util.Loader.loadClass(Loader.java:71)
    at org.mortbay.jetty.servlet.Holder.doStart(Holder.java:73)
    at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:242)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
    at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
    at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
    at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
    at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
    at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
    at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:188)
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
    at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
    at java.lang.Thread.run(Thread.java:724)

Follow my homepage: 跟随我的主页：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="java.util.List" %>
<%@ page import="com.google.appengine.api.users.User" %>
<%@ page import="com.google.appengine.api.users.UserService" %>
<%@ page import="com.google.appengine.api.users.UserServiceFactory" %>
<%@ page import="com.bruno.bariotti.Pessoa" %>
<%@ page import="com.bruno.bariotti.PessoaDao" %>

<!DOCTYPE html>

<html>
<head>
<title>Pessoas</title>
<link rel="stylesheet" type="text/css" href="css/main.css"/>
</head>

<body>
<%
PessoaDao dao = PessoaDao.INSTANCE;
List<Pessoa> pessoas;
pessoas = dao.listPessoas();
%>

Numero total de pessoas: <% pessoas.size(); %> Pessoas.

<table>
<tr>
<th>Nome</th>
<th>Idade</th>
<%for (Pessoa p : pessoas) {%>
<tr>
<td>
<%p.getNome(); %>
</td>
<td>
<%p.getIdade();  %>
</td>
</tr>
<% } %>
</table>

<hr />

<div class="main">
<div class="headline">Nova Pessoa</div>

<form action="/new" method="post" accept-charset="utf-8">
<table>

<tr>
<td><lable for="nome">Nome</lable></td>
<td><input type="text" name="nome" id="nome" size="200"/></td>
</tr>

<tr>
<td><lable for="idade">Idade</lable></td>
<td><input type="text" name="idade" id="idade" size="3"/></td>
</tr>

</table>
</form>

</body>
</html>

Answer 1

This issue happens when you use JDK 1.8 and deploy your application, say, using maven eg mvn appengine:update . 当您使用JDK 1.8并部署您的应用程序（例如，使用maven，例如mvn appengine:update时，就会发生此问题。

During the update process Google AppEngine maven plugin compiles JSP files (as on the image below) using JDK 1.8. 在更新过程中，Google AppEngine maven插件使用JDK 1.8编译JSP文件（如下图所示）。 Generated class files gets version number 52.0 which are not currently supported by Google AppEngine (hence your error: Unsupported major.minor version 52.0 ). 生成的类文件的版本号为52.0，Google AppEngine当前不支持该版本号（因此，您的错误： 不支持的major.minor 52.0版 ）。

JSP编译

Workaround is quite simple: set JAVA_HOME variable to point to your JDK 1.7 解决方法非常简单：将JAVA_HOME变量设置为指向您的JDK 1.7

Example in Windows: Windows中的示例：

set JAVA_HOME=c:\Program Files\Java\jdk1.7.0_05

After that you have to run mvn appengine:update again, which will fix the problem. 之后，您必须再次运行mvn appengine:update ，这将解决问题。

JDK 1.7 is required by Google actually. Google实际需要JDK 1.7 。 You can find out more on Using Apache Maven: Requirements . 您可以在《使用Apache Maven：需求》中找到更多信息。

错误的App Engine-

问题描述

1 个解决方案

解决方案1
1 2014-08-27 15:45:16

错误的App Engine-

问题描述

1 个解决方案

解决方案1 1 2014-08-27 15:45:16

解决方案1
1 2014-08-27 15:45:16