Question

我正在使用jackson解析器，并且在请求获取时它与我的其余模板一起使用但是当我尝试发布帖子时它会给我以下错误：

web.util.NestedServletException: 
Handler processing failed; 
nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/JsonProcessingException

我不知道出了什么问题。我正在尝试发送一个帖子请求，它的正文应该是一个对象：

@RequestMapping(value = "dogCreated", method = RequestMethod.POST)
@ResponseStatus(HttpStatus.CREATED)
public String createDog(@ModelAttribute Dog dog, BindingResult result, Model model){
RestTemplate rest = new RestTemplate();
//      List< HttpMessageConverter<?> > messageConverters = new ArrayList< HttpMessageConverter<?> >();   
//      // empty list created
//
//      messageConverters.add( new MappingJackson2HttpMessageConverter() );      
//      messageConverters.add( new StringHttpMessageConverter() );

        rest.getMessageConverters().add(new MappingJackson2HttpMessageConverter());/*This is where the error occurs*/
        rest.getMessageConverters().add(new StringHttpMessageConverter());

        ObjectMapper mapper = new ObjectMapper();
        TypeFactory typeFactory = mapper.getTypeFactory();

        String response = rest.postForObject("https://rest-service.herokuapp.com/createDog", dog, String.class);
        System.out.println(response);

我在我的pom.xml中包含了两个Jackson依赖项：

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-core-asl</artifactId>
    <version>1.9.13</version>
</dependency>
<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-mapper-asl</artifactId>
    <version>1.9.13</version>
</dependency>

有谁能告诉我哪里出错了？更具体地说它出现了错误：

rest.getMessageConverters().add(new MappingJackson2HttpMessageConverter());

非常感谢任何帮助。

这是完整的堆栈跟踪

org.springframework.web.util.NestedServletException: Handler processing failed; nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/JsonProcessingException
    org.springframework.web.servlet.DispatcherServlet.triggerAfterCompletionWithError(DispatcherServlet.java:1303)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:977)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:869)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/JsonProcessingException
    com.dogs.controller.DogController.createDog(DogController.java:42)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:483)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:869)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

java.lang.ClassNotFoundException: com.fasterxml.jackson.core.JsonProcessingException
    org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1305)
    org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1157)
    com.dogs.controller.DogController.createDog(DogController.java:42)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:483)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:869)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

Answer 1

您遇到的问题是因为您使用的是最新版本不支持的非常旧的依赖项：

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-core-asl</artifactId>
    <version>1.9.13</version>
</dependency>
<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-mapper-asl</artifactId>
    <version>1.9.13</version>
</dependency>

由于上面的库发生了一些变化，你需要删除这些依赖项并添加新的：

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.5.4</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.5.4</version>
</dependency>

更改并查看结果。如果它有效，请将其作为回答。

Spring JsonProcessingExceptin用于休息模板的NoClassDefFoundError

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