type Exception report
message Servlet.init() for servlet dispatcherServlet threw exception
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Servlet.init() for servlet dispatcherServlet threw exception org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1008) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1852) java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) java.lang.Thread.run(Thread.java:745)
root cause
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter': Cannot create inner bean 'org.springframework.http.converter.json.MappingJackson2HttpMessageConverter#0' of type [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter] while setting bean property 'messageConverters' with key [3]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.http.converter.json.MappingJackson2HttpMessageConverter#0': Failed to introspect bean class [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter] for lookup method metadata: could not find class that it depends on; nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/util/DefaultPrettyPrinter$Indenter org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:313) org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:122) org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveManagedList(BeanDefinitionValueResolver.java:382) org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:157) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1531) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1276) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761) org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866) org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542) org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:634) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:682) org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:553) org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494) org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136) javax.servlet.GenericServlet.init(GenericServlet.java:160) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1008) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1852) java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) java.lang.Thread.run(Thread.java:745)
报错信息如上，在网上查了很多资料，大致原因是因为缺少json包相关的配置，然后就按照网上的教程开始配置，把Jackson 1.9.x的包加上了，spring-mvc.xml配置文件也配置好了，但依旧报错。
自己想了想，网上的资料大部分都是springmvc 3.x的相关配置说明，可能是由于版本太低导致的，可看报错信息根本看不出来，自己试了下比较高的版本，2.5.0的版本，结果发现，一切都OK了。
也不需要在xml里配置，也不需要在方法上添加 @ResponseBody 标签了。
pom.xml配置如下：
<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.5.0</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> <version>2.5.0</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.5.0</version> </dependency>
转载于:https://www.cnblogs.com/StarFine/p/6836177.html
相关资源：JAVA上百实例源码以及开源项目