Jackson错误和注意

版权声明： https://blog.csdn.net/qq_35370790/article/details/79134730

当在Windows是系统中springMVC使用@ResponseBody不配置json转换器照样可以把对象转换为json,但把项目放在Linux上就会出错。

注意：spring和Jackson有三个jar包：jackson-annotations   jackson-core   jackson-databind   jackson-databind-2.8.4-sources这几个包的版本一定要一致，不然就会报如下的错误，也有可能在Windows上能运行但在Linux上不能运行

错误信息：

org.springframework.web.util.NestedServletException: Handler processing failed; nested exception is java.lang.NoSuchMethodError: com.fasterxml.jackson.core.JsonGenerator.writeStartObject(Ljava/lang/Object;)V
	org.springframework.web.servlet.DispatcherServlet.triggerAfterCompletionWithError(DispatcherServlet.java:1280)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:958)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
	org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
	org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
	org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383)
	org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
	org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344)
	org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261)
	com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)
	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
Root Cause

java.lang.NoSuchMethodError: com.fasterxml.jackson.core.JsonGenerator.writeStartObject(Ljava/lang/Object;)V
	com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:515)
	com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:30)
	com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:292)
	com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:2493)
	org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.writeInternal(MappingJackson2HttpMessageConverter.java:253)
	org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:208)
	org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:143)
	org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:89)
	org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:193)
	org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:71)
	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:122)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
	org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
	org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
	org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383)
	org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
	org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344)
	org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261)
	com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)
	org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

正确形式：jackson-annotations-2.8.0.jar  jackson-core-2.8.0.jar  jackson-databind-2.8.4.jar

错误形式：jackson-annotations-2.8.0.jar  jackson-core-2.4.4.jar  jackson-databind-2.8.4.jar