后台json将Date转换成指定格式

你的名字 2021-09-30 04:12 521阅读 0赞

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.version>2.1</net.sf.version>
            
            <fastjson.version>1.2.47</fastjson.version>
            
            <jackson.version>2.4.1</jackson.version>
            
            <junit.version>4.12</junit.version>
        </properties>
    
        <dependencies>
            
            <dependency>
                <groupId>net.sf.json-lib</groupId>
                <artifactId>json-lib</artifactId>
                <version>${net.sf.version}</version>
                <classifier>jdk15</classifier>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>${fastjson.version}</version>
            </dependency>
            
            <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>
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>${junit.version}</version>
                <scope>test</scope>
            </dependency>
        </dependencies>
    </project>

参考链接：

[https://blog.csdn.net/qq\_41570658/article/details/89383110][https_blog.csdn.net_qq_41570658_article_details_89383110]

[https://blessht.iteye.com/blog/2018901][https_blessht.iteye.com_blog_2018901]

[https://www.cnblogs.com/wangshen31/p/8961691.html][https_www.cnblogs.com_wangshen31_p_8961691.html]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTA5OTk4MDk_size_16_color_FFFFFF_t_70]: /images/20210923/daf2737474394558b71626cf74de3d4e.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTA5OTk4MDk_size_16_color_FFFFFF_t_70 1]: /images/20210923/04197fd9ccd94976bf4daf0a8c2d3c37.png
[https_blog.csdn.net_qq_41570658_article_details_89383110]: https://blog.csdn.net/qq_41570658/article/details/89383110
[https_blessht.iteye.com_blog_2018901]: https://blessht.iteye.com/blog/2018901
[https_www.cnblogs.com_wangshen31_p_8961691.html]: https://www.cnblogs.com/wangshen31/p/8961691.html