后台json将Date转换成指定格式-蒲公英云

我经常用到的后台json转换工具有：fastjson（1.2.47），netsf（2.1），jackson（2.4.1）

一、需求说明

比如：我现在有一个list，里面实体类中有一个属性是Date

watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTA5OTk4MDk_size_16_color_FFFFFF_t_70

我想要转换的最终结果为：

[{"birthday":"1994-03-01 06:20:00","id":101,"name":"张三"},{"birthday":"1995-06-01 06:20:00","id":102,"name":"李四"},{"birthday":"1996-09-01 06:20:00","id":103,"name":"王五"}]

watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTA5OTk4MDk_size_16_color_FFFFFF_t_70 1

二、代码实现

由于问题比较简单，这三种json工具的代码我直接贴下：

package com.kittycoder.test1;
import com.alibaba.fastjson.JSONObject;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.kittycoder.test1.po.Student_Fj;
import com.kittycoder.test1.po.Student_Jks;
import com.kittycoder.test1.po.Student_Nsf;
import net.sf.json.JSONArray;
import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonValueProcessor;
import org.junit.Test;
import java.lang.reflect.Constructor;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Locale;
/**
 * Created by shucheng on 2019-7-22 下午 23:16
 */
public class OutParamTest {
    private List list;
    // https://blog.csdn.net/qq_41570658/article/details/89383110
    @Test
    public void fjTest() throws Exception {
        list = generateList(Student_Fj.class);
        String jsonStr = JSONObject.toJSONString(list);
        System.out.println(jsonStr);
    }
    // https://blessht.iteye.com/blog/2018901
    @Test
    public void nsfTest() throws Exception {
        list = generateList(Student_Nsf.class);
        JsonConfig jsonConfig = new JsonConfig();
        jsonConfig.registerJsonValueProcessor(Date.class, new JsonDateValueProcessor());
        JSONArray jsonArray = JSONArray.fromObject(list, jsonConfig);
        System.out.println(jsonArray.toString());
    }
    // https://www.cnblogs.com/wangshen31/p/8961691.html
    @Test
    public void jksTest() throws Exception {
        list = generateList(Student_Jks.class);
        ObjectMapper mapper = new ObjectMapper();
        String jsonStr = mapper.writeValueAsString(list);
        System.out.println(jsonStr);
    }
    // 生成测试用的List
    private <T> List<T> generateList(final Class<T> clazz) throws Exception {
        final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        final Constructor<T> ctr = clazz.getDeclaredConstructor(Integer.class, String.class, Date.class);
        return new ArrayList<T>(){
   {
            add(ctr.newInstance(101, "张三", sdf.parse("1994-03-01 06:20:00")));
            add(ctr.newInstance(102, "李四", sdf.parse("1995-06-01 06:20:00")));
            add(ctr.newInstance(103, "王五", sdf.parse("1996-09-01 06:20:00")));
        }};
    }
}
class JsonDateValueProcessor implements JsonValueProcessor {
    private String format = "yyyy-MM-dd HH:mm:ss";
    public JsonDateValueProcessor() {
    }
    public JsonDateValueProcessor(String format) {
        this.format = format;
    }
    @Override
    public Object processArrayValue(Object o, JsonConfig jsonConfig) {
        return process(o);
    }
    @Override
    public Object processObjectValue(String s, Object o, JsonConfig jsonConfig) {
        return process(o);
    }
    private Object process(Object value) {
        if (value instanceof Date) {
            SimpleDateFormat sdf = new SimpleDateFormat(format, Locale.CHINA);
            return sdf.format(value);
        }
        return value == null ? "" : value.toString();
    }
}

Student_Fj.java（针对fastjson情形的实体类）：

package com.kittycoder.test1.po;
import com.alibaba.fastjson.annotation.JSONField;
import java.util.Date;
/**
 * Created by shucheng on 2019-7-22 下午 22:43
 */
public class Student_Fj {
    private Integer id;
    private String name;
    @JSONField(format = "yyyy-MM-dd HH:mm:ss")
    private Date birthday; // 假设存的时间是精确到秒的
    public Student_Fj() {
    }
    public Student_Fj(Integer id, String name, Date birthday) {
        this.id = id;
        this.name = name;
        this.birthday = birthday;
    }
    // 省略setter、getter方法
}

Student_Nsf.java（针对netsf情形的实体类）：

package com.kittycoder.test1.po;
import java.util.Date;
/**
 * Created by shucheng on 2019-7-22 下午 22:43
 */
public class Student_Nsf {
    private Integer id;
    private String name;
    private Date birthday; // 假设存的时间是精确到秒的
    public Student_Nsf() {
    }
    public Student_Nsf(Integer id, String name, Date birthday) {
        this.id = id;
        this.name = name;
        this.birthday = birthday;
    }
    // 省略setter、getter方法
}

Student_Jks.java（针对jackson情形的实体类）：

package com.kittycoder.test1.po;
import com.fasterxml.jackson.annotation.JsonFormat;
import java.util.Date;
/**
 * Created by shucheng on 2019-7-22 下午 22:43
 */
public class Student_Jks {
    private Integer id;
    private String name;
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
    private Date birthday; // 假设存的时间是精确到秒的
    public Student_Jks() {
    }
    public Student_Jks(Integer id, String name, Date birthday) {
        this.id = id;
        this.name = name;
        this.birthday = birthday;
    }
    // 省略setter、getter方法
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.kittycoder</groupId>
    <artifactId>JSONLibDemo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <!-- net.sf -->
        <net.sf.version>2.1</net.sf.version>
        <!-- fastjson -->
        <fastjson.version>1.2.47</fastjson.version>
        <!-- jackson -->
        <jackson.version>2.4.1</jackson.version>
        <!-- junit -->
        <junit.version>4.12</junit.version>
    </properties>
    <dependencies>
        <!-- net.sf json -->
        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>${net.sf.version}</version>
            <classifier>jdk15</classifier>
        </dependency>
        <!-- Alibaba Fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>${fastjson.version}</version>
        </dependency>
        <!-- jackson相关包 -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <!-- 单元测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>