java多层嵌套集合的json，如何获取多层集合中所需要的value

就很简单的一个问题折磨了整整一天，好在压抑的心情终于释放了，终于闲下来觉得是不是应该记录一下。

首先这个json串是从外网接口返回的数据，想要了解的朋友们可以复制到json解析器中看一下格式：https://www.json.cn/#

{"status":"True","biz_result":[{"PartyFunctionCode":"NBEPORT","PartyIdentifier":"container","PartyName":"宁波电子口岸","ManifestInfo":[{"LadingBillNumber":"COSU6224023460B","ShippingCompanyName":"","VesselNameCode":"COSCO YINGKOU","VesselName":"COSCO YINGKOU","PlaceOfLoading":"","PlaceOfDischarge":"","VoyageNumber":"130W","DirectionCode":"","VesselCallNumber":"","IMONumber":""}],"ContainerInfo":[{"ContainerNumber":"FCIU9840537","ContainerOperator":"COS","SealNumber":"11374417","CodeOfSizeAndType":"","ContainerLoadingStatusCode":"","ContainerTareWeight":"0","TransportMeansType":"","VehicleNumber":"","ContainerStatusInformation":[{"ImExIdentifier":"","TransportStatusCode":"码头已经放行","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-10-25 17:34:49","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"","PlaceOrLocation":"","Remark":"宁波电子口岸","Status":"DOCKPASS","EventName":""},{"ImExIdentifier":"E","TransportStatusCode":"重箱进港","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-10-24 13:29:00","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"BLCT3","PlaceOrLocation":"北仑四期码头","Remark":"宁波电子口岸","Status":"INOUT","EventName":"进港"},{"ImExIdentifier":"E","TransportStatusCode":"海关放行","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-10-25 11:04:37","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"","PlaceOrLocation":"","Remark":"宁波电子口岸","Status":"CUSPASS","EventName":"海关放行"},{"ImExIdentifier":"","TransportStatusCode":"27301 装载舱单数据传输成功。","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-10-31 13:44:41","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"","PlaceOrLocation":"","Remark":"宁波电子口岸","Status":"MFT","EventName":"装载舱单"},{"ImExIdentifier":"E","TransportStatusCode":"重箱装船","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-11-01 16:13:00","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"BLCT3","PlaceOrLocation":"北仑四期码头","Remark":"宁波电子口岸","Status":"LOAD","EventName":"装船"},{"ImExIdentifier":"","TransportStatusCode":"开船","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-11-01 22:00:00","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"BLCT3","PlaceOrLocation":"北仑四期码头","Remark":"宁波电子口岸","Status":"BERTH","EventName":"离港"}]}]},{"PartyFunctionCode":"NBEPORT","PartyIdentifier":"container","PartyName":"宁波电子口岸","ManifestInfo":[{"LadingBillNumber":"COSU6224023460A","ShippingCompanyName":"","VesselNameCode":"COSCO YINGKOU","VesselName":"COSCO YINGKOU","PlaceOfLoading":"","PlaceOfDischarge":"","VoyageNumber":"130W","DirectionCode":"","VesselCallNumber":"","IMONumber":""}],"ContainerInfo":[{"ContainerNumber":"FCIU9840537","ContainerOperator":"COS","SealNumber":"11374417","CodeOfSizeAndType":"","ContainerLoadingStatusCode":"","ContainerTareWeight":"0","TransportMeansType":"","VehicleNumber":"","ContainerStatusInformation":[{"ImExIdentifier":"","TransportStatusCode":"码头已经放行","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-10-25 17:34:49","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"","PlaceOrLocation":"","Remark":"宁波电子口岸","Status":"DOCKPASS","EventName":""},{"ImExIdentifier":"E","TransportStatusCode":"重箱进港","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-10-24 13:29:00","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"BLCT3","PlaceOrLocation":"北仑四期码头","Remark":"宁波电子口岸","Status":"INOUT","EventName":"进港"},{"ImExIdentifier":"E","TransportStatusCode":"海关放行","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-10-25 11:04:27","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"","PlaceOrLocation":"","Remark":"宁波电子口岸","Status":"CUSPASS","EventName":"海关放行"},{"ImExIdentifier":"","TransportStatusCode":"27301 装载舱单数据传输成功。","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-10-31 13:44:41","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"","PlaceOrLocation":"","Remark":"宁波电子口岸","Status":"MFT","EventName":"装载舱单"},{"ImExIdentifier":"E","TransportStatusCode":"重箱装船","TransportStatusNameEN":"","DateOrTimeOrPeriod":"2019-11-01 16:13:00","TimeZoneIdentifier":"PRC","PlaceLocationQualifier":"NBEPORT","PlaceOrLocationIdentification":"BLCT3","PlaceOrLocation":"北仑四期码头","Remark":"宁波电子口岸","Status":"LOAD","EventName":"装船"}]}]}],"error":""}

Json串

期间用了alibab的fastjson包想要一层一层剥开这个json，结果浪费了许多时间还是没有效果，估计是方法使用错了，这里就直接贴上成功的方法。

首先还是先建了实体类，这里比较简单，就是按照json的格式一层一层往下写，就直接贴代码了。（getset和构造器我就不贴了，有点太占空间了）

 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import java.io.Serializable;
 import java.util.List;

 @JsonIgnoreProperties(ignoreUnknown = true)
 @SuppressWarnings("serial")
 public class Result implements Serializable {

     private String status;
     private List<biz_result> biz_result;
     private String error;

 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import java.io.Serializable;
 import java.util.List;

 @JsonIgnoreProperties(ignoreUnknown = true)
 @SuppressWarnings("serial")
 public class biz_result implements Serializable {
     private String PartyFunctionCode;
     private String PartyIdentifier;
     private String PartyName;
     private List<ManifestInfo> ManifestInfo ;
     private List<ContainerInfo> ContainerInfo ;

 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import java.io.Serializable;

 @JsonIgnoreProperties(ignoreUnknown = true)
 @SuppressWarnings("serial")
 public class ManifestInfo implements Serializable {
     private String LadingBillNumber;
     private String ShippingCompanyName;
     private String VesselNameCode;
     private String VesselName;
     private String PlaceOfLoading;
     private String PlaceOfDischarge;
     private String VoyageNumber;
     private String DirectionCode;
     private String VesselCallNumber;
     private String IMONumber;

 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import java.io.Serializable;
 import java.util.List;

 @JsonIgnoreProperties(ignoreUnknown = true)
 @SuppressWarnings("serial")
 public class ContainerInfo  implements Serializable {

     private String ContainerNumber;
     private String ContainerOperator;
     private String SealNumber;
     private String CodeOfSizeAndType;
     private String ContainerLoadingStatusCode;
     private String ContainerTareWeight;
     private String TransportMeansType;
     private String VehicleNumber;
     private List<ContainerStatusInformation> ContainerStatusInformation ;

 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import java.io.Serializable;

 @JsonIgnoreProperties(ignoreUnknown = true)
 @SuppressWarnings("serial")
 public class ContainerStatusInformation implements Serializable {

     private String ImExIdentifier;
     private String TransportStatusCode;
     private String TransportStatusNameEN;
     private String DateOrTimeOrPeriod;
     private String TimeZoneIdentifier;
     private String PlaceLocationQualifier;
     private String PlaceOrLocationIdentification;
     private String PlaceOrLocation;
     private String Remark;
     private String Status;
     private String EventName;

才想起来要不要折叠一下，这会不会太长了，但是我实在太懒了，对不起我就不去重新操作了。

实体类建完以后我就尝试了一下，也不再使用alibab的fastjson，使用如下这个包：

import net.sf.json.JSONObject;

maven依赖如下：

<dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
            <classifier>jdk15</classifier>
</dependency>

最终代码如下：

 import net.sf.json.JSONArray;
 import net.sf.json.JSONObject;

 public class Test02 {

     public static void main(String[]args){

         String json = "这是上面巨长的JSON";

         //得到json对象
         JSONObject jsonObject = JSONObject.fromObject(json);
         //获取其中的biz_result数组
         JSONArray biz_result = jsonObject.getJSONArray("biz_result");
         //获取数组中的某位元素
         String biz_resultString = biz_result.getString(0);
         //将数组中的这个数组再次转换成json对象
         JSONObject jsonObject1 = JSONObject.fromObject(biz_resultString);
         //通过getString获取value
         String manifestInfo = jsonObject1.getString("ManifestInfo");
         //去除首位中括号得到json格式
         String substring = manifestInfo.substring(1);
         String subString = substring.substring(0,substring.length()-1);
         //得到json格式以后再转换成json对象
         JSONObject jb3 = JSONObject.fromObject(subString);
         //得到需要的值。
         String vesselName = jb3.getString("VesselName");
         System.out.println(vesselName);

     }
 }

还是得养成写注释的习惯，要是不写注释贴上来，我自己都看着不舒服，最终得到了需要的数据：

COSCO YINGKOU

1234567.