java - 尝试运行我的项目时抛出 BeanCreationException

Question

我正在尝试使用 Spring 开发 RESTful Web 服务，然后将其部署在 Google App Engine 上。该服务的客户端将是一个 Android 应用程序。我是第一次使用 spring 和 GAE，所以我不太清楚。

我正在尝试关注 this tutorial 。当我尝试将我的项目作为 Web 应用程序项目运行时，我收到异常提示音:http://pastebin.com/07cVSx2c - 这是整个输出。

以下是第一行:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping#0': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.handler.MappedInterceptor#0': Cannot create inner bean '(inner bean)#57459491' of type [org.springframework.web.servlet.handler.ConversionServiceExposingInterceptor] while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#57459491': Cannot resolve reference to bean 'org.springframework.format.support.FormattingConversionServiceFactoryBean#0' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.format.support.FormattingConversionServiceFactoryBean#0': Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: java.time.format.FormatStyle is a restricted class. Please see the Google  App Engine developer's guide for more details.
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:547)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:755)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
    at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548)
    at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
    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 org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
    at org.mortbay.jetty.Server.doStart(Server.java:224)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:255)
    at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:288)
    at com.google.appengine.tools.development.AutomaticInstanceHolder.startUp(AutomaticInstanceHolder.java:26)
    at com.google.appengine.tools.development.AbstractModule.startup(AbstractModule.java:87)
    at com.google.appengine.tools.development.Modules.startup(Modules.java:105)
    at com.google.appengine.tools.development.DevAppServerImpl.doStart(DevAppServerImpl.java:258)
    at com.google.appengine.tools.development.DevAppServerImpl.access$000(DevAppServerImpl.java:47)
    at com.google.appengine.tools.development.DevAppServerImpl$1.run(DevAppServerImpl.java:213)
    at com.google.appengine.tools.development.DevAppServerImpl$1.run(DevAppServerImpl.java:211)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:211)
    at com.google.appengine.tools.development.DevAppServerMain$StartAction.apply(DevAppServerMain.java:277)
    at com.google.appengine.tools.util.Parser$ParseResult.applyArgs(Parser.java:48)
    at com.google.appengine.tools.development.DevAppServerMain.run(DevAppServerMain.java:219)
    at com.google.appengine.tools.development.DevAppServerMain.main(DevAppServerMain.java:210)

所以这是我到目前为止所拥有的:web.xml

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

    <servlet>
        <servlet-name>mvc-dispatcher</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>mvc-dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/mvc-dispatcher-servlet.xml</param-value>
    </context-param>

    <listener>
        <listener-class>
                    org.springframework.web.context.ContextLoaderListener
        </listener-class>
    </listener>

    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>
</web-app>

mvc-dispatcher-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <context:component-scan
        base-package="com.example.myserver.server">
        <context:exclude-filter type="regex"
            expression="com.example.myserver.Marker.*" />
    </context:component-scan>

    <mvc:annotation-driven />

    <!-- Bean to show you Di in GAE, via Spring, also init the MovieController -->
    <bean
        class="com.example.myserver.MarkerController">
        <property name="markers">
            <value>Hello World</value>
        </property>
    </bean>
</beans>

MarkerController.java

package com.example.myserver;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
@RequestMapping("/markers")
public class MarkerController {
    private String markers;

    @RequestMapping(method = RequestMethod.GET)
    public String getMarkers() {
        return this.markers;
    }

    public void setMarkers(String markers) {
        this.markers = markers;
    }

}

你能告诉我问题是什么以及如何解决它吗？我尝试搜索此错误 java.lang.NoClassDefFoundError: java.time.format.FormatStyle 但我没有找到任何内容..提前致谢!

Answer 1

首先，GAE doesn't fully support Java 8 。其次，GAE 限制 Java 标准库中的哪些类可以使用，哪些类不能使用。列出了允许的类 here .

通常类受到限制，因为它们访问 GAE 中不可用的资源(例如写入文件系统)。然而，我的猜测是 FormatStyle 只是受到限制，因为它是一个 Java 8 类，而 GAE 尚未 catch Java 8。

您收到的 NoClassDefFoundError 只是尝试访问 GAE 不允许的类。您的选择是自己重新发明该类，找到已经重新发明它的其他人，或者等待 GAE 最终添加对它的支持。