java.lang.UnsupportedClassVersionError：com / google / mystorage / server / GreetingServiceImpl：不支持的major.minor版本51.0 [英] java.lang.UnsupportedClassVersionError: com/google/mystorage/server/GreetingServiceImpl : Unsupported major.minor version 51.0

问题描述

我是JAVA和AppEngine的新手。我已经安装了JDK-1.6，但仍然发生该异常。项目文件部署在服务器上没有任何错误，但是当打开链接时，它会给出错误。在我的应用程序日志中，它只显示一个unsupportefclassversionerror异常。我已经安装了JDK-1.6，但它不工作。我也安装了JDK-1.5，但是在部署阶段它给出了所有排列未编译的错误。我的项目XML文件低于

XML文件是



web.xml

 <？xml version =1.0encoding =UTF-8？> 
< web-app xmlns：xsi =http://www.w3.org/2001/XMLSchema-instance
 xsi：schemaLocation =http://java.sun.com/xml / ns / javaee 
 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd
 version =2.5
 xmlns =http：// java.sun.com/xml/ns/javaee\"> 
 
<！ -  Servlets  - > 
< servlet> 
< servlet-name> greetServlet< / servlet-name> 
< servlet-class> com.google.mystorage.server.GreetingServiceImpl< / servlet-class> 
< / servlet> 
 
< servlet-mapping> 
< servlet-name> greetServlet< / servlet-name> 
< url-pattern> / mystorage / greet< / url-pattern> 
< / servlet-mapping> 
 
 <！ - 要投放的默认页面 - > 
< welcome-file-list> 
< welcome-file> index.jsp< / welcome-file> 
< / welcome-file-list> 
 
< / web-app> 
  

appengine-web.xml
>

 <？xml version =1.0encoding =utf-8？> 
< appengine-web-app xmlns =http://appengine.google.com/ns/1.0> 
< application> cloudisapp< / application> 
< version> 2< / version> 
 
 <！ -   -  
默认情况下，App Engine将请求串行发送到给定的Web服务器。 
允许App Engine并行发送多个请求。指定：
 
< threadsafe> true< / threadsafe> 
  - > 
 
 <！ - 配置GWT文件的服务/缓存 - > 
< static-files> 
< include path =**/> 
< include path =favicon.ico/> 
<！ - 以下行需要App Engine 1.3.2 SDK  - > 
< include path =**。nocache。*expiration =0s/> 
 
< include path =**。cache。*expiration =365d/> 
< exclude path =**。gwt.rpc/> 
< / static-files> 
 
 <！ - 配置java.util.logging  - > 
< system-properties> 
< property name =java.util.logging.config.filevalue =WEB-INF / logging.properties/> 
< / system-properties> 
<会话启用>真实< /会话启用> 
< / appengine-web-app> 
  

datastore-indexes.xml
>

 <？xml version =1.0encoding =UTF-8？> 
< datastore-indexes autoGenerate =true> 
< / datastore-indexes> 
  

请帮助我

解决方案

使用Java 6 javac重新编译。

i am new to JAVA and AppEngine. I have installed JDK-1.6, but still that exception occurs. Project files are deployed on server without any errors, but when open link, then it gives an error. In my application logs it shows only one exception which is "unsupportefclassversionerror". i have installed JDK-1.6, but its not working. I have also installed JDK-1.5 but at deploying stage it gives "All Permutation not compiled" error. My project XML files are below

XML files are

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
              http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         version="2.5"
         xmlns="http://java.sun.com/xml/ns/javaee">

  <!-- Servlets -->
  <servlet>
    <servlet-name>greetServlet</servlet-name>
    <servlet-class>com.google.mystorage.server.GreetingServiceImpl</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>greetServlet</servlet-name>
    <url-pattern>/mystorage/greet</url-pattern>
  </servlet-mapping>

  <!-- Default page to serve -->
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>

</web-app>

appengine-web.xml

<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
  <application>cloudisapp</application>
  <version>2</version>

  <!--
    By default, App Engine sends requests serially to a given web server.
    To allow App Engine to send multiple requests in parallel specify:

      <threadsafe>true</threadsafe>
  -->

  <!-- Configure serving/caching of GWT files -->
  <static-files>
    <include path="**" />
    <include path="favicon.ico"/>
    <!-- The following line requires App Engine 1.3.2 SDK -->
    <include path="**.nocache.*" expiration="0s" />

    <include path="**.cache.*" expiration="365d" />
    <exclude path="**.gwt.rpc" />
  </static-files>

  <!-- Configure java.util.logging -->
  <system-properties>
    <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
  </system-properties>
  <sessions-enabled>true</sessions-enabled>
</appengine-web-app>

datastore-indexes.xml

<?xml version="1.0" encoding="UTF-8"?>
<datastore-indexes  autoGenerate="true">
</datastore-indexes> 

Please help me

解决方案

You have compiled for Java 7 which Java 6 cannot understand.

Recompile with a Java 6 javac.

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