java - Jackson:我怎样才能忽略 getter 而解析 setter？

Question

我需要序列化没有给定字段的 bean，但使用该字段反序列化该 bean。我用@JsonIgnore在 setter/getter 上，和 @JsonIgnore(false)在 setter 上:

public class TestJson {
    private String s1, s2;

    @JsonIgnore
    public String getS1() {
        return s1;
    }

    @JsonIgnore(false)
    public void setS1(String s1) {
        this.s1 = s1;
    }

    public String getS2() {
        return s2;
    }

    public void setS2(String s2) {
        this.s2 = s2;
    }

    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        TestJson bean = new TestJson();
        bean.setS1("test1");
        bean.setS2("test2");
        System.out.println(mapper.writeValueAsString(bean));

        String json = "{\"s1\":\"test1\",\"s2\":\"test2\"}";
        bean = mapper.readValue(json, TestJson.class);
        System.out.println("s1=" + bean.getS1());
        System.out.println("s2=" + bean.getS2());
    }
}

序列化效果良好，得到预期值{"s2":"test2"} .

但是@JsonIgnore(false)在 setter 上似乎不起作用。

我期望:

s1=test1
s2=test2

但是得到了:

s1=null
s2=test2

如何在球场上制作二传手 s1工作？

Answer 1

您可以将@JsonProperty与JsonProperty.Access.WRITE_ONLY一起使用

from docs

Access setting that means that the property may only be written (set) for deserialization, but will not be read (get) on serialization, that is, the value of the property is not included in serialization.

public class TestJson {

    @JsonProperty(access = JsonProperty.Access.WRITE_ONLY)
    private String s1;
    private String s2;


    public String getS1() {
        return s1;
    }

    public void setS1(String s1) {
        this.s1 = s1;
    }

    public String getS2() {
        return s2;
    }

    public void setS2(String s2) {
        this.s2 = s2;
    }
}

这也应该有效

public class TestJson {
    private String s1;
    private String s2;


    @JsonIgnore
    public String getS1() {
        return s1;
    }

    @JsonProperty
    public void setS1(String s1) {
        this.s1 = s1;
    }

    public String getS2() {
        return s2;
    }

    public void setS2(String s2) {
        this.s2 = s2;
    }
}