org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: (was java.

约定不等于承诺〃 2022-06-01 01:06 189阅读 0赞

springmvc在发布的时候，ajax读取出现如下错误。主要原因是 序列化的问题，当实体类有个别属性是空的时候，则会报以下错误。

同时，查看到有个end，则是分页的原因。（查看是否继承了分页的类，进行修改）

解决方法如下：

org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: (was java.lang.NullPointerException) (through reference chain: com.regaltec.ida40.pacify.dto.PacifyTaskReceiveDTO["end"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: com.regaltec.ida40.pacify.dto.PacifyTaskReceiveDTO["end"])
    	org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.writeInternal(MappingJackson2HttpMessageConverter.java:207)
    	org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:180)
    	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:188)
    	org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:69)
    	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:122)
    	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:743)
    	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:672)
    	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:82)
    	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:933)
    	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:867)
    	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
    	org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:844)
    	javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
    	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
    	javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    	com.regaltec.common.filter.SystemFilter.loginIsValid(SystemFilter.java:325)
    	com.regaltec.common.filter.SystemFilter.doFilter(SystemFilter.java:160)
    	com.regaltec.ida40.common.ResponsibilityFilter.doFilter(ResponsibilityFilter.java:58)
    	com.regaltec.common.util.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:104)
    	org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

（一）添加注释@JsonIgnoreProperties

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

在类上边添加注释，为空的时候不序列化

@JsonIgnoreProperties
    public class PacifyTaskReceiveDTO {

}

（二）还是报错，那么去掉继承序列化的类。同时，我这里不需要分页，只需要提取到数据给前台ajax读取即可，因此取消继承分页的类，成功解决方法。

（三）重新发布即可。