需要解析JAVA中JSON对象内部的JSON数组

我正在尝试解析datas.JSON中的JSON数据。我需要使用bean/POJO类解析排除数据。JSON数据如下： 排除名单：{ 服务级别：[sl1、sl2、sl3]， 项目：[ABC，XYZ]}

我已经为排除列表创建了POJO类，但无法在ECLIPSE IDE的控制台中获取和打印。Mypojo类：

List<String> serviceLevel;
List<String> item;
//with gettter and setters.

我的主要课程如下：

public static void main(String[] args)
            throws JsonParseException, JsonMappingException, IOException, ParseException, JSONException {
    File jsonFile = new File("C:\\Users\\sameepra\\Videos\\datas.json");
    ObjectMapper mapper = new ObjectMapper();  
    mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,false);
    ExclusionList exclusionlist=mapper.readValue(jsonFile,ExclusionList.class);
    List<String> excllist=exclusionlist.getServiceLevel();
    for (int i = 0; i < excllist.size(); i++) {
        System.out.println(excllist.get(i));
    }
}

---

在线程主java.lang.NullPointerException中将错误获取为异常

是否初始化了List ExcepList？？它已在提供的行中初始化为字符串：字符串类型列表*发布控制台日志

You need to wrap your pojo class in another containing an ExclusionList property.
Try this. The examples below uses lombok for getters , setters and default constructor.


import java.util.List;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

import lombok.Data;

@Data
public class ExclusionListWrapper {

    @JsonProperty("ExclusionList")
    private ExclusionList exclusionList;

    @Data
    class ExclusionList {
        List<String>    serviceLevel;
        List<String>    item;

    }

    public static void main(String[] args) throws Exception {
        String data = "{\"ExclusionList\" : {\"serviceLevel\" : [\"sl1\",\"sl2\",\"sl3\"], \"item\" : [\"ABC\",\"XYZ\"]}}";
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        ExclusionListWrapper exclusionlistWrapper = mapper.readValue(data, ExclusionListWrapper.class);
        List<String> excllist = exclusionlistWrapper.getExclusionList().getServiceLevel();
        for (int i = 0; i < excllist.size(); i++) {
            System.out.println(excllist.get(i));
        }
    }

}