Java操作JSON数据(3)--fastjson操作JSON数据

fastjson是阿里巴巴的开源JSON解析库，它可以解析JSON格式的字符串，支持将Java Bean序列化为JSON字符串，也可以从JSON字符串反序列化到JavaBean。本文介绍下fastjson的基本使用方法，包括序列化和反序列化；文中所使用到的软件版本：Java 1.8.0_191、fastjson1.2.62。

1、引入依赖

<dependency>

    <groupId>com.alibaba</groupId>

    <artifactId>fastjson</artifactId>

    <version>1.2.62</version>

</dependency>

2、序列化

    public static String serialize() {

        MyBean bean = new MyBean();

        bean.setS("测试字符串");

        Calendar calendar = Calendar.getInstance();

        calendar.add(Calendar.HOUR_OF_DAY, -1);

        bean.setD(calendar.getTime());

        List<MyBean> list = new ArrayList<MyBean>();

        list.add(bean);

        Map<String, List<MyBean>> map = new HashMap<String, List<MyBean>>();

        map.put("data", list);

        /*

         * "yyyy-MM-dd HH:mm:ss" 设置日期格式，也可在类属性上使用@JSONField(format="yyyy-MM-dd HH:mm:ss")注解来设置

         * SerializerFeature.WriteMapNullValue 输出值为null的字段

         * SerializerFeature.WriteNullStringAsEmpty 字符串如果为null则输出""

         */

        String result = JSON.toJSONStringWithDateFormat(map, "yyyy-MM-dd HH:mm:ss", SerializerFeature.WriteMapNullValue, SerializerFeature.WriteNullStringAsEmpty);

        System.out.println(result);

        return result;

    }

3、反序列化

    public static void deserialize() {

        String s = serialize();

        TypeReference<Map<String, List<MyBean>>> type = new TypeReference<Map<String, List<MyBean>>>(){};

        Map<String, List<MyBean>> map = JSON.parseObject(s, type);

        System.out.println(map);

        //直接通过api获取相应数据

        JSONObject jsonObject = JSON.parseObject(s);

        JSONArray JsonArray = jsonObject.getJSONArray("data");

        JSONObject bean = JsonArray.getJSONObject(0);

        System.out.println(bean.getString("s"));

        //...

    }

4、完整例子

package com.inspur.demo.json;

import java.util.ArrayList;

import java.util.Calendar;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import com.alibaba.fastjson.JSON;

import com.alibaba.fastjson.JSONArray;

import com.alibaba.fastjson.JSONObject;

import com.alibaba.fastjson.TypeReference;

import com.alibaba.fastjson.serializer.SerializerFeature;

/**

 * fastjson操作JSON数据

 */

public class FastjsonCase {

    /**

     * 序列化

     */

    public static String serialize() {

        MyBean bean = new MyBean();

        bean.setS("测试字符串");

        Calendar calendar = Calendar.getInstance();

        calendar.add(Calendar.HOUR_OF_DAY, -1);

        bean.setD(calendar.getTime());

        List<MyBean> list = new ArrayList<MyBean>();

        list.add(bean);

        Map<String, List<MyBean>> map = new HashMap<String, List<MyBean>>();

        map.put("data", list);

        /*

         * "yyyy-MM-dd HH:mm:ss" 设置日期格式，也可在类属性上使用@JSONField(format="yyyy-MM-dd HH:mm:ss")注解来设置

         * SerializerFeature.WriteMapNullValue 输出值为null的字段

         * SerializerFeature.WriteNullStringAsEmpty 字符串如果为null则输出""

         */

        String result = JSON.toJSONStringWithDateFormat(map, "yyyy-MM-dd HH:mm:ss", SerializerFeature.WriteMapNullValue, SerializerFeature.WriteNullStringAsEmpty);

        System.out.println(result);

        return result;

    }

    /**

     * 反序列化

     */

    public static void deserialize() {

        String s = serialize();

        TypeReference<Map<String, List<MyBean>>> type = new TypeReference<Map<String, List<MyBean>>>(){};

        Map<String, List<MyBean>> map = JSON.parseObject(s, type);

        System.out.println(map);

        //直接通过api获取相应数据

        JSONObject jsonObject = JSON.parseObject(s);

        JSONArray JsonArray = jsonObject.getJSONArray("data");

        JSONObject bean = JsonArray.getJSONObject(0);

        System.out.println(bean.getString("s"));

        //...

    }

    public static void main(String[] args) {

        serialize();

        deserialize();

    }

}

FastjsonCase

package com.inspur.demo.json;

import java.util.Arrays;

import java.util.Date;

public class MyBean {

    private String s = "字符串";

    private String s2;

    private String s3 = "字符串3";

    private int i = 123;

    private Integer i2;

    private char c = '到';

    private char[] c2 = new char[]{'a', 'b'};

    private Date d = new Date();

    private Date[] d2 = new Date[]{new Date(), new Date()};

    public String getS() {

        return s;

    }

    public void setS(String s) {

        this.s = s;

    }

    public String getS2() {

        return s2;

    }

    public void setS2(String s2) {

        this.s2 = s2;

    }

    public String getS3() {

        return s3;

    }

    public void setS3(String s3) {

        this.s3 = s3;

    }

    public int getI() {

        return i;

    }

    public void setI(int i) {

        this.i = i;

    }

    public Integer getI2() {

        return i2;

    }

    public void setI2(Integer i2) {

        this.i2 = i2;

    }

    public char getC() {

        return c;

    }

    public void setC(char c) {

        this.c = c;

    }

    public char[] getC2() {

        return c2;

    }

    public void setC2(char[] c2) {

        this.c2 = c2;

    }

    public Date getD() {

        return d;

    }

    public void setD(Date d) {

        this.d = d;

    }

    public Date[] getD2() {

        return d2;

    }

    public void setD2(Date[] d2) {

        this.d2 = d2;

    }

    @Override

    public String toString() {

        return "MyBean [s=" + s + ", s2=" + s2 + ", s3=" + s3 + ", i=" + i + ", i2=" + i2 + ", c=" + c + ", c2="

                + Arrays.toString(c2) + ", d=" + d + ", d2=" + Arrays.toString(d2) + "]";

    }

}

MyBean