无法将Json字符串转换为Java对象

Question

我无法将给定的Json字符串转换为java对象

@JsonIgnoreProperties(ignoreUnknown = true)
public class DevPol {

    private String id;
    private Header header;

    //Setters and Getters
}

@JsonIgnoreProperties(ignoreUnknown = true)
public class Header {

    private String name;
    private String lastUpdate;
    private int priority;
    private boolean active;

    //Setters and Getters
}

import com.fasterxml.jackson.databind.ObjectMapper;
public class ConvertJsonToJava {

    static String apiResult = "[ {\"Id\":\"5899503ad06f7f0008817430\",  \"Header\":{  \"name\":\"ClCol\"," + 
            "         \"lastupdate\":\"2017-02-07T04:42:34.654Z\", \"priority\":1,  \"active\":true } }," + 
            "   { \"Id\":\"5899503ad06f7f0008817431\",\"Header\":{  \"name\":\"SysPol\"," +
            " \"lastupdate\":\"2017-02-07T04:42:34.659Z\", \"priority\":2, \"active\":true } }]"; 

    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        DevPol[] devPOlArr = mapper.readValue(apiResult, DevPol[].class);
        for(DevPol devPol: devPOlArr) {

            System.out.println(devPol.getId());
        }
    }

}

Answer 1

问题是json字段名和java类字段中的大写字母。

如果可能，在json和Java中重命名'id'->'id'。否则，您应该将json属性名添加到java字段：

public class DevPol {

    @JsonProperty("Id")
    private String Id;
    @JsonProperty("Header")
    private Header Header;

//Setters and Getters

}