Question

我是JAVA / Jackson世界的新手;我正在尝试使用jackson库将传入的json映射到pojo。我对传入的JSON没有控制权。下面是hte json结构。

{
 "kind": "html",
 "responseCode": 200,
 "DisplayRules": {
  "Age": {
   "Max": 40
  },
  "Weight": {
   "Max": 100
  }
 }

以下是基于springboot的app类。

@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(Include.NON_NULL)
public class JSONResults {
private String kind;
private DisplayRules displayRules;
//Getters & Setters
}

@JsonIgnoreProperties(ignoreUnknown = true)
public class DisplayRules {
private Age age;
private Weight weight;
//Getters & Setters
@Override
    public String toString(){
        return  " - " + Weight.toString();
    }
    }


@JsonIgnoreProperties(ignoreUnknown = true)
public class Age {
    private int Max;
//Getters & Setters
}
@JsonIgnoreProperties(ignoreUnknown = true)
public class Weight {
    private int Max;
//Getters & Setters
@Override
        public String toString(){
            return  "Weight=  "+ weight;
        }
}

有时JSON会遗漏年龄或体重。所以如果缺少整个对象（如下所示）。如何在班上处理？我尝试使用基于此thread的 @JsonInclude（Include.NON_NULL），但它不起作用。任何帮助都非常感谢。

{
 "kind": "html",
 "responseCode": 200,
 "DisplayRules": {
  "Age": {
   "Max": 40
  }//missing weight
 }

除此之外，我还能够使用＆＃34; Jackson Tree Model＆＃34;来解决这个问题。 .has方法;但我的json有超过100个＆＃34;对象＆＃34 ;;所以很难检查每个对象的可用性。

==================堆栈跟踪========================= java。 lang.NullPointerException at com.cards.jsondata.DisplayRules.toString（RuleGroups.java:44）at java.lang.String.valueOf（String.java:2982）at java.lang.StringBuilder.append（StringBuilder.java:131）at com.cards.jsondata.JSONResults.JSONString（JSONResults.java:54）at at com.cards.service.GetResultsImpl.getJSONResults（GetResultsImpl.java:61）在 com.cards.controller.RunReports.generateReports（RunReports.java:48） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method）at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）在 sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.lang.reflect.Method.invoke（Method.java:497）at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke（InvocableHandlerMethod.java:205）在 org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest（InvocableHandlerMethod.java:133）在 org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle（ServletInvocableHandlerMethod.java:97）在 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod（RequestMappingHandlerAdapter.java:827）在 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal（RequestMappingHandlerAdapter.java:738）在 org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle（AbstractHandlerMethodAdapter.java:85）在 org.springframework.web.servlet.DispatcherServlet.doDispatch（DispatcherServlet.java:967）在 org.springframework.web.servlet.DispatcherServlet.doService（DispatcherServlet.java:901）在 org.springframework.web.servlet.FrameworkServlet.processRequest（FrameworkServlet.java:970）在 org.springframework.web.servlet.FrameworkServlet.doGet（FrameworkServlet.java:861）在javax.servlet.http.HttpServlet.service（HttpServlet.java:635）at org.springframework.web.servlet.FrameworkServlet.service（FrameworkServlet.java:846）在javax.servlet.http.HttpServlet.service（HttpServlet.java:742）at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:231）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:166）在 org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52）在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:193）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:166）在 org.springframework.web.filter.RequestContextFilter.doFilterInternal（RequestContextFilter.java:99）在 org.springframework.web.filter.OncePerRequestFilter.doFilter（OncePerRequestFilter.java:107）在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:193）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:166）在 org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal（HttpPutFormContentFilter.java:105）在 org.springframework.web.filter.OncePerRequestFilter.doFilter（OncePerRequestFilter.java:107）在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:193）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:166）在 org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal（HiddenHttpMethodFilter.java:81）在 org.springframework.web.filter.OncePerRequestFilter.doFilter（OncePerRequestFilter.java:107）在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:193）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:166）在 org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal（CharacterEncodingFilter.java:197）在 org.springframework.web.filter.OncePerRequestFilter.doFilter（OncePerRequestFilter.java:107）在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:193）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:166）在 org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:198）在 org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:96）在 org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:478）在 org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:140）在 org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:80）在 org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:87）在 org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:342）在 org.apache.coyote.http11.Http11Processor.service（Http11Processor.java:799）在 org.apache.coyote.AbstractProcessorLight.process（AbstractProcessorLight.java:66）在 org.apache.coyote.AbstractProtocol $ ConnectionHandler.process（AbstractProtocol.java:868）在 org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor.doRun（NioEndpoint.java:1455）在 org.apache.tomcat.util.net.SocketProcessorBase.run（SocketProcessorBase.java:49）在 java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1142）在 java.util.concurrent.ThreadPoolExecutor中的$ Worker.run（ThreadPoolExecutor.java:617）在 org.apache.tomcat.util.threads.TaskThread $ WrappingRunnable.run（TaskThread.java:61）在java.lang.Thread.run（Thread.java:745）

使用Jackson

0 个答案: