Question

要求：

将json文件中的选定字段收集到POJO（字段名称不匹配）
更新POJO的其他非映射字段
使用POJO字段名称转换回jsonNode

问题：第1步和第2步都很好。将POJO转换回JsonNode时，我无法在POJO字段名称中获取它。任何人都可以建议一种方法来获得这个吗？

下面是我的代码

@JsonIgnoreProperties(ignoreUnknown = true)
public class MyPOJO {

@JsonProperty("Firstname")
private String name;

@JsonProperty("Country")
private String nationality;

private String state;

//getters and setters
}

逻辑

     ObjectMapper map = new ObjectMapper();
    JsonNode root =map.readTree(new Main().getResorceFile());
    List<MyPOJO> myList = new ArrayList<MyPOJO>();

    for(JsonNode each : root){
        MyPOJO myPOJO = new MyPOJO();
        myPOJO= map.readValue(each.toString(),MyPOJO.class);
        System.out.println(myPOJO.toString());
        myList.add(myPOJO);
    }
    for(MyPOJO p : myList){
        JsonNode node = map.convertValue(p,JsonNode.class);
        System.out.println((node.toString()));
    }

Json文件

    {
        {
            "Firstname":"Tez",
            "Lastname":"Morris",
            "Country":"US"
        },
        {
            "Firstname":"Kip",
            "Lastname":"Lee",
            "Country":"US"
        },
        {
            "Firstname":"Pam",
            "Lastname":"Carr",
            "Country":"US"
        },
        {
            "Firstname":"lin",
            "Lastname":"Dale",
            "Country":"US"
        }
    }

输出：

    Main{name='Tez', nationality='US', state='null'}
    Main{name='Kip', nationality='US', state='null'}
    Main{name='Pam', nationality='US', state='null'}
    Main{name='lin', nationality='US', state='null'}
    {"state":null,"Firstname":"Tez","Country":"US"}
    {"state":null,"Firstname":"Kip","Country":"US"}
    {"state":null,"Firstname":"Pam","Country":"US"}
    {"state":null,"Firstname":"lin","Country":"US"}

预期产出

    Main{name='Tez', nationality='US', state='null'}
    Main{name='Kip', nationality='US', state='null'}
    Main{name='Pam', nationality='US', state='null'}
    Main{name='lin', nationality='US', state='null'}
    {"state":null,"name":"Tez","nationality":"US"}
    {"state":null,"name":"Kip","nationality":"US"}
    {"state":null,"name":"Pam","nationality":"US"}
    {"state":null,"name":"lin","nationality":"US"}

Answer 1

解决方案是将@JsonProperty放在具有不同值的getter和setter上，例如：

[…]
private String nationality;

@JsonProperty("nationality")
public String getNationality() {
    return nationality;
}

@JsonProperty("Country")
public void setNationality(String nationality) {
    this.nationality = nationality;
}
[…]

getter执行序列化，即setter反序列化。

使用POJO字段名将POJO转换为JsonNode

1 个答案: