使用 Jackson 的 ObjectMapper 的 JSON 对象顺序 [英] Order of JSON objects using Jackson's ObjectMapper

问题描述

我正在使用 ObjectMapper 来做我的 java-json 映射.

I'm using ObjectMapper to do my java-json mapping.

ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();
ow.writeValue(new File( fileName +".json"), jsonObj);

这是我的java类:

public class Relation {

private String id;
private String source;
private String target;
private String label;
private List<RelAttribute> attributes;

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}

public String getSource() {
    return source;
}

public void setSource(String source) {
    this.source = source;
}

public String getTarget() {
    return target;
}

public void setTarget(String target) {
    this.target = target;
}

public String getLabel() {
    return label;
}
public void setLabel(String label) {
    this.label = label;
}

public void setAttributes(List<RelAttribute> attributes) {
    this.attributes = attributes;
}

public List<RelAttribute> getAttributes() {
    return attributes;
}

}

这是我得到的:

{
    "id" : "-75da69d3-79c8-4000-a3d8-b10350a57a7e",
    "attributes" : [ {
      "attrName" : "ID",
      "attrValue" : ""
    }, {
      "attrName" : "Description",
      "attrValue" : "Primary Actor"
    }, {
      "attrName" : "Status",
      "attrValue" : ""
    } ],
    "label" : "new Label",
    "target" : "-46b238ac-b8b3-4230-b32c-be9707f8b691",
    "source" : "-daa34638-061a-45e0-9f2e-35afd6c271e0"
  }

所以我现在的问题是，我怎样才能得到这个 json 输出:

So my question now is, how can I get this json output:

{
    "id" : "-75da69d3-79c8-4000-a3d8-b10350a57a7e",
    "label" : "new Label",
    "target" : "-46b238ac-b8b3-4230-b32c-be9707f8b691",
    "source" : "-daa34638-061a-45e0-9f2e-35afd6c271e0",
    "attributes" : [ {
      "attrName" : "ID",
      "attrValue" : ""
    }, {
      "attrName" : "Description",
      "attrValue" : "Primary Actor"
    }, {
      "attrName" : "Status",
      "attrValue" : ""
    } ]

  }

我希望它的顺序与我的 java 声明中的顺序相同.有没有办法指定它?也许有注释或类似的东西?

I want it with same order as in my java declaration. Is there a way to specify it ? Maybe with annotations or stuff like that ?

推荐答案

@JsonPropertyOrder({ "id", "label", "target", "source", "attributes" })
public class Relation { ... }

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