springmvccontroller返回json出错解决

1、出错的地方：

@RequestMapping(value = \

@JsonSerialize(include=JsonSerialize.Inclusion.NON_NULL) public @ResponseBody

JSONObject query(@RequestParam(\@RequestParam(\

@RequestParam(\@RequestParam(\@RequestParam(\@RequestParam(\@RequestParam(\

@RequestParam(\

LogInfo info = populateQueryParam(startTime, endTime, oid, cid, payChannel, deviceType, phone, pageSize, startIndex);

// 总记录数

Long totalCount = logMoniterService.queryLogInfoCount(info);

if (totalCount == null) { totalCount = 0L; }

List list = logMoniterService.queryLogInfo(info);

JSONObject retData = new JSONObject(); retData.put(\ retData.put(\ retData.put(\

retData.put(\ return retData; }

2、结果报错：

HTTP Status 500 - Could not write JSON: Object is null (through reference chain:

net.sf.json.JSONObject["data"]->net.sf.json.JSONArray[0]->net.sf.json.JSONObject["createTime"]->net.sf.json.JSONNull["empty"]); nested exception is

org.codehaus.jackson.map.JsonMappingException: Object is null (through reference chain:

net.sf.json.JSONObject["data"]->net.sf.json.JSONArray[0]->net.sf.json.JSONObject["createTime"]->net.sf.json.JSONNull["empty"])

message Could not write JSON: Object is null (through reference chain: net.sf.json.JSONObject["data"]->net.sf.json.JSONArray[0]->net.sf.json.JSONObject["createTime"]->net.sf.json.JSONNull["empty"]); nested exception is

org.codehaus.jackson.map.JsonMappingException: Object is null (through reference chain:

net.sf.json.JSONObject["data"]->net.sf.json.JSONArray[0]->net.sf.json.JSONObject["createTime"]->net.sf.json.JSONNull["empty"])

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: Object is null (through reference chain: net.sf.json.JSONObject["data"]->net.sf.json.JSONArray[0]->net.sf.json.JSONObject["createTime"]->net.sf.json.JSONNull["empty"]); nested exception is 
org.codehaus.jackson.map.JsonMappingException: Object is null (through reference chain: 
net.sf.json.JSONObject["data"]->net.sf.json.JSONArray[0]->net.sf.json.JSONObject["createTime"]->net.sf.json.JSONNull["empty"]) 
org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.writeInternal(MappingJacksonHttpMessageConverter.java:203) org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:179) 
org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:148) 
org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:90) 
org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:189) 
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:745) 
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) 
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925) 
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856) 
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936) 
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:838) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:647) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812) 
javax.servlet.http.HttpServlet.service(HttpServlet.java:728) 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:343) 
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:260) 
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) 
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) 

root cause

org.codehaus.jackson.map.JsonMappingException: Object is null (through reference chain: 
net.sf.json.JSONObject["data"]->net.sf.json.JSONArray[0]->net.sf.json.JSONObject["createTime"]->net.sf.json.JSONNull["empty"]) 
org.codehaus.jackson.map.JsonMappingException.wrapWithPath(JsonMappingException.java:218) 
org.codehaus.jackson.map.JsonMappingException.wrapWithPath(JsonMappingException.java:183) 
org.codehaus.jackson.map.ser.std.SerializerBase.wrapAndThrow(SerializerBase.java:140)   
 3原因分析： 
可能是json序列化的问题 代码修改为 
@RequestMapping(value = \public @ResponseBody 
Map query(@RequestParam(\@RequestParam(\
@RequestParam(\@RequestParam(\@RequestParam(\@RequestParam(\@RequestParam(\
@RequestParam(\  
LogInfo info = populateQueryParam(startTime, endTime, oid, cid, payChannel, deviceType, phone, pageSize, startIndex);   
// 总记录数 
Long totalCount = logMoniterService.queryLogInfoCount(info);   
if (totalCount == null) { totalCount = 0L; }   
List list = logMoniterService.queryLogInfo(info);   
Map result = new HashMap();   
result.put(\ result.put(\ result.put(\ 
result.put(\ return result; }   
4、问题解决 
 
                
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