java序列化对象，根据不同配置动态改变属性名
使用场景：自己项目对接多个外部系统，各个外部系统使用的字段并没有统一，所以要根据不同系统动态的输出序列化数据，使适应各个系统的要求
实现方式
使用自定义注解和fastjson实现需求
fastjson的NameFilter的作用：序列化时，属性名变成自己指定的名称
实现过程
自定义注解一：MyParamName
package xin.yangshuai.cipher.json;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;/** * MyParamName * * @author shuai * @date 2021/3/23 */@Retention(RetentionPolicy.RUNTIME)@Target({ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER})public @interface MyParamName { String value() default ""; NameEle[] names() default {};} value、names都是非必填
value：默认序列化的名称
names：自定义注解二，数组形式
自定义注解二：NameEle
package xin.yangshuai.cipher.json;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;/** * NameEle * * @author shuai * @date 2021/3/24 */@Retention(RetentionPolicy.RUNTIME)@Target({ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER})public @interface NameEle { String id(); String value();} id：唯一标识，确定序列化后的属性名
value：定义序列化后的属性名
手写MyNameFilter，实现fastjson的NameFilter
package xin.yangshuai.cipher.json;import com.alibaba.fastjson.serializer.NameFilter;import java.lang.reflect.Field;/** * MyNameFilter * * @author shuai * @date 2021/3/23 */public class MyNameFilter implements NameFilter { private String id; public MyNameFilter() { } public MyNameFilter(String id) { this.id = id; } @Override public String process(Object o, String name, Object value) { try { Field field = o.getClass().getDeclaredField(name); MyParamName myParamName = field.getDeclaredAnnotation(MyParamName.class); NameEle[] nameEles = myParamName.names(); String defaultName = myParamName.value(); if (nameEles.length == 0 && defaultName.length() > 0) { return defaultName; } for (NameEle n : nameEles) { if (id.equals(n.id())) { return n.value(); } } } catch (Exception e) { return name; } return name; }} 构造方法传递id属性的值，与自定义注解二的id进行匹配，匹配成功则使用对应的属性名
实体类，属性上添加自定义注解
package xin.yangshuai.cipher.json;import com.alibaba.fastjson.JSON;/** * Person * * @author shuai * @date 2021/3/23 */public class Person { @MyParamName(names = { @NameEle(id = "ln", value = "i_d"), @NameEle(id = "jl", value = "_id")}) private String id; @MyParamName("NAME") private String name; private String age; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } @Override public String toString() { return "Person{" + "id='" + id + '\'' + ", name='" + name + '\'' + ", age='" + age + '\'' + '}'; }}运行主方法测试
public static void main(String[] args) { Person person = new Person(); person.setAge("18"); person.setId("001"); person.setName("张三"); String s = JSON.toJSONString(person, new MyNameFilter("jl")); System.out.println(s); String s1 = JSON.toJSONString(person, new MyNameFilter("ln")); System.out.println(s1);} 结果为：
{"age":"18","_id":"001","NAME":"张三"} {"age":"18","i_d":"001","NAME":"张三"}
参考
# java序列化对象，根据不同配置动态改变属性名
原文：https://juejin.cn/post/7101517823695912990