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Spring 4 and Rest WS integration

由 旧城冷巷雨未停 提交于 2019-12-30 08:20:49

问题


I have been doing a poc on Spring4 and RestWS integration. I am new to both with barely a weeks exposure. I am following instructions from blogs. I understand that in Spring 4 and restWS setup jackson-core/anotation/databind 2 is to be used for correct message converstion of JSON <-> Java object to happen. Also org.springframework.http.converter.json.MappingJackson2HttpMessageConverter is to be used for message conversion. I satisfied all these requirements. However when I try to start application, I get bean create exception. stack

SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'regionController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.web.servlet.View com.leggmason.lmpamfs.controllers.RegionController.jsonView_i; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.view.json.MappingJacksonJsonView#0' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.web.servlet.view.json.MappingJacksonJsonView]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:703)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4961)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5455)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.web.servlet.View com.leggmason.lmpamfs.controllers.RegionController.jsonView_i; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.view.json.MappingJacksonJsonView#0' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.web.servlet.view.json.MappingJacksonJsonView]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
    ... 22 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.view.json.MappingJacksonJsonView#0' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.web.servlet.view.json.MappingJacksonJsonView]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1076)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1021)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1017)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:960)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:858)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
    ... 24 more
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.web.servlet.view.json.MappingJacksonJsonView]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:164)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1069)
    ... 35 more
Caused by: java.lang.NoClassDefFoundError: org/codehaus/jackson/map/ObjectMapper
    at org.springframework.web.servlet.view.json.MappingJacksonJsonView.(MappingJacksonJsonView.java:65)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:148)
    ... 37 more
Caused by: java.lang.ClassNotFoundException: org.codehaus.jackson.map.ObjectMapper
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
    ... 43 more

It seems that something is wrong with MappingJacksonJsonView class. Could following from factory file be the cause of trouble ?

 <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView">  
       <property name="contentType" value="text/plain"/>  
  </bean>

Am I supposed to replace this class as well? I will help assistance to fix this.

Thanks, Suvojit


回答1:


You are currently using the MappingJacksonJsonView which is designed to work with Jackson1 .

You mention the following:

I am not using Jackson 1 api's. jars in my lib are, jackson-core-2.0.2, jackson-annotation-2.3.0, jackson-bindings 2.3.0.

Which means you have Jackson2 on your classpath. Jackson1 and Jackson2 aren't compatible (different packages, different classes etc.).

You have 2 possible solutions

  1. Don't use Jackson2 and switch your dependencies to Jackson1
  2. Replace the MappingJacksonJsonView with the MappingJackson2JsonView



回答2:


For Spring4 Rest + Json POC The following App Context is enough 

<?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/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <context:component-scan base-package="org.name.controller" />
    <!-- Enables the Spring MVC @Controller programming model -->
    <mvc:annotation-driven />
    <mvc:resources location="/statics/" mapping="/statics/**"/>
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

Make sure you have dependency for Jackson (e.g. in maven) 

<!-- jackson so spring mvc will handle json responses out of the box -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.3.0</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.3.0</version>
</dependency>

You do not specifically need to define MappingJackson2JsonView; MappingJackson2HttpMessageConverter/MappingJacksonHttpMessageConverter will be created automatically when jackson is the the class path (the default is only when ContentType/Accept are application/json).

Jackson1 is deprecated, but still supported if from any reason you are limited to Jackson1 See Spring 4 docs



来源：https://stackoverflow.com/questions/23631868/spring-4-and-rest-ws-integration

标签
java
json
Spring
rest
spring-4
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