如何使用 Java 中的 Jackson 库对属性的顺序进行序列化?
@JsonPropertyOrder 是一个用于类级别的注解。它使用字段列表作为属性,该列表定义了字段在 JSON 序列化对象所生成的字符串中出现的顺序。包含在注解声明中的属性可先序列化(按定义的顺序),然后才是定义中未包含的任何属性。
语法
public @interface JsonPropertyOrder
示例
import com.fasterxml.jackson.core.*; import com.fasterxml.jackson.databind.*; import com.fasterxml.jackson.annotation.JsonPropertyOrder; import java.util.*; import java.io.*; public class JsonPropertyOrderTest { public static void main(String args[]) throws JsonGenerationException, JsonMappingException, IOException { Employee emp = new Employee(); emp.setFirstName("Adithya"); emp.setEmpId(25); emp.setLastName("Jai"); emp.getTechnologies().add("Java"); emp.getTechnologies().add("Scala"); emp.getTechnologies().add("Python"); ObjectMapper mapper = new ObjectMapper(); mapper.writerWithDefaultPrettyPrinter().writeValue(System.out, emp); } } // Employee class @JsonPropertyOrder({ "firstName", "lastName", "technologies", "empId" }) class Employee { private int empId; private String firstName; private String lastName; private List<String> technologies = new ArrayList<>(); public int getEmpId() { return empId; } public void setEmpId(int empId) { this.empId = empId; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public List<String> getTechnologies() { return technologies; } public void setTechnologies(List<String> technologies) { this.technologies = technologies; } }
输出
{ "firstName" : "Adithya", "lastName" : "Jai", "technologies" : [ "Java", "Scala", "Python" ], "empId" : 125 }
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