com.alibaba.fastjson常用的SerializerFeature

个人笔记

SerializerFeature.WriteNullListAsEmpty , // List字段如果为null,输出为[],而非null
SerializerFeature.WriteNullStringAsEmpty, //字符类型字段如果为null,输出为”“,而非null
SerializerFeature.WriteDateUseDateFormat, //如果时间是data、时间戳类型，按照这种格式初始化时间 "yyyy-MM-dd HH:mm"
SerializerFeature.WriteNullNumberAsZero, //数值字段如果为null,输出为0,而非null
SerializerFeature.WriteNullBooleanAsFalse ,//Boolean字段如果为null,输出为false,而非null
SerializerFeature.SkipTransientField , //类中的Get方法对应的Field是transient，序列化时将会被忽略。默认为true
SerializerFeature.DisableCircularReferenceDetect //消除对同一对象循环引用的问题，默认为false

案例

package com.cn.dl;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.sql.Timestamp;
import java.util.Date;

/**
 * Created by yanshao on 2018/11/26.
 */
@Data
@NoArgsConstructor
@Builder
@AllArgsConstructor
public class Stu {
    private String name;
    private Integer age;
    private Boolean isMan;
    private String address = "beijing";
    private transient String interest = "ball";
    private Date createDate = new Date();
}

package com.cn.dl;

import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.PropertyFilter;
import com.alibaba.fastjson.serializer.SerializerFeature;
import org.junit.Test;

public class SpringbootAopTestApplicationTests {

	@Test
	public void contextLoads() {

		Stu stu = new Stu();
		System.out.println(toJSON(stu));
		System.out.println(toJSON2(stu));
		System.out.println(toJSON3(stu));
	}

	/**
	 * 过滤字段值等于null的字段
	 * */
	private PropertyFilter filter = new PropertyFilter() {
		/**
		 * @param obj 当前对象
		 * @param key 当前对象属性
		 * @param value 当前对象属性值
		 * @return
		 * */
		@Override
		public boolean apply(Object obj, String key, Object value) {
			if(value != null){
				return true;
			}
			return false;
		}
	};

	/**
	 * 过滤字段值等于null的字段
	 * */
	private PropertyFilter nullFilter = (obj, key,value) -> {
		if (value != null){
			return true;
		}
		return false;
	};

	private String toJSON(Object obj){
		return  JSONObject.toJSONString(
				obj,
				SerializerFeature.WriteNullListAsEmpty,
				SerializerFeature.WriteNullStringAsEmpty,
				SerializerFeature.WriteDateUseDateFormat,
				SerializerFeature.WriteNullNumberAsZero,
				SerializerFeature.WriteNullBooleanAsFalse,
				SerializerFeature.DisableCircularReferenceDetect
		);
	}

	private String toJSON2(Object obj){
		return  JSONObject.toJSONString(
				obj,
				filter,
				SerializerFeature.WriteNullListAsEmpty,
				SerializerFeature.WriteNullStringAsEmpty,
				SerializerFeature.WriteDateUseDateFormat,
				SerializerFeature.WriteNullNumberAsZero,
				SerializerFeature.WriteNullBooleanAsFalse,
				SerializerFeature.DisableCircularReferenceDetect
		);
	}

	private String toJSON3(Object obj){
		return  JSONObject.toJSONString(
				obj,
				nullFilter,
				SerializerFeature.WriteNullListAsEmpty , // List字段如果为null,输出为[],而非null
				SerializerFeature.WriteNullStringAsEmpty, //字符类型字段如果为null,输出为”“,而非null
				SerializerFeature.WriteDateUseDateFormat, //如果时间是data、时间戳类型，按照这种格式初始化时间 "yyyy-MM-dd HH:mm"
				SerializerFeature.WriteNullNumberAsZero, //数值字段如果为null,输出为0,而非null
				SerializerFeature.WriteNullBooleanAsFalse ,//Boolean字段如果为null,输出为false,而非null
				SerializerFeature.SkipTransientField , //类中的Get方法对应的Field是transient，序列化时将会被忽略。默认为true
				SerializerFeature.DisableCircularReferenceDetect //消除对同一对象循环引用的问题，默认为false
		);
	}

}

/**
	 * 过滤字段值等于null的字段
	 * */
	private PropertyFilter nullFilter = (obj, key,value) -> {
		if (value != null){
			return true;
		}
		return false;
	};

注意点：

 1、这个方法用来过滤对象obj中为null的字段，其中key是字段名，value是字段值；

 2、如果javaBean上的字段用transient修饰，就会忽略掉这个字段；

测试结果：

{"address":"beijing","age":0,"createDate":"2018-11-27 10:15:06","isMan":false,"name":""}
{"address":"beijing","createDate":"2018-11-27 10:15:06"}
{"address":"beijing","createDate":"2018-11-27 10:15:06"}