fastjson处理json字符串成java对象之前的相互转换

约定不等于承诺〃 2022-10-28 04:57 188阅读 0赞

1 这段代码主要是利用fastjson的封装方法处理json字符串成java对象之前的相互转换

package com.neo.util;
    
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.JSONObject;
    import com.alibaba.fastjson.TypeReference;
    import com.alibaba.fastjson.serializer.JSONLibDataFormatSerializer;
    import com.alibaba.fastjson.serializer.SerializeConfig;
    import com.alibaba.fastjson.serializer.SerializerFeature;
    
    import java.util.List;
    import java.util.Map;
    
    /**
     * Created by hqj on 2021/2/5.
     */
    public class Json {
        private static SerializeConfig config;
        private static SerializerFeature[] features = {
                //输出空值字段
                SerializerFeature.WriteMapNullValue,
                //如果数组结果为null,则输出为[],而不是null
                SerializerFeature.WriteNullListAsEmpty,
                //数值字段为null,则输出为0,而不是null
                SerializerFeature.WriteNullNumberAsZero,
                //Boolean字段为null,则输出为false,而不是null
                SerializerFeature.WriteNullBooleanAsFalse,
                //字符类型如果为null,则输出为" ",而不是null
                SerializerFeature.WriteNullStringAsEmpty
        };
        static {
            config = new SerializeConfig();
            //使用json-lib兼容的日期输出格式
            config.put(java.util.Date.class,new JSONLibDataFormatSerializer());
        }
    
        /**
         * 将一个对象装换为Json字符串
         */
        public static String ToJSONString(Object object) {
            return JSONObject.toJSONString(object,config,features);
        }
    
        /**
         * 将Json字符串转换为Object类型的
         * */
        public  static  Object ToObject(String str){
            return JSON.parse(str);
        }
    
        /**
         * 将Json字符串转换为实例
         * */
        public static <T> T ToObject(String str,Class<T> t){
            return JSON.parseObject(str,t);
        }
    
        /**
         * 将Json转换为指定类型的List
         * */
        public static <T> List<T> ToList(String str, Class<T> t){
            return JSON.parseArray(str,t);
        }
    
        /**
         * 将Json转换为Map
         * */
        public static <T> Map<String,T> ToMap(String str){
            return (Map<String, T>) JSONObject.parseObject(str);
        }
    }

下面是测试代码

package com.neo.util; 
    
    import com.neo.entity.Media;
    import com.neo.entity.News;
    import com.neo.entity.SysLog;
    import org.junit.Test;
    import org.junit.Before; 
    import org.junit.After;
    
    import java.time.LocalDateTime;
    import java.util.ArrayList;
    import java.util.List;
    
    /** 
    * Json Tester. 
    * 
    * @author <Authors name> 
    * @since <pre>02/05/2021</pre> 
    * @version 1.0 
    */ 
    public class JsonTest { 
    
    @Before
    public void before() throws Exception { 
    } 
    
    @After
    public void after() throws Exception { 
    } 
    
    /** 
    * 
    * Method: ToJSONString(Object object) 
    * 
    */ 
    @Test
    public void testToJSONString() throws Exception { 
    //TODO: Test goes here...
        SysLog log = new SysLog();
        log.setUserName("jack");
        log.setAction("add");
        log.setEvent("insert");
        log.setHost("127.0.0.1");
        log.setInsertTime(LocalDateTime.now());
    
        String strJson = Json.ToJSONString(log);
        System.out.println(strJson);
    } 
    
    /** 
    * 
    * Method: ToObject(String str) 
    * 
    */ 
    @Test
    public void testToObjectStr() throws Exception { 
        String strJson ="{\"action\":\"add\",\"event\":\"insert\",\"host\":\"127.0.0.1\",\"insertTime\":\"2021-02-05T14:58:13.891\",\"logId\":0,\"userName\":\"jack\"}";
        Object obj = Json.ToObject(strJson);
        System.out.println(obj);
    } 
    
    /** 
    * 
    * Method: ToObject(String str, Class<T> t) 
    * 
    */ 
    @Test
    public void testToObjectForStrT() throws Exception {
        String strJson ="{\"action\":\"add\",\"event\":\"insert\",\"host\":\"127.0.0.1\",\"insertTime\":\"2021-02-05T14:58:13.891\",\"logId\":0,\"userName\":\"jack\"}";
        SysLog obj = Json.ToObject(strJson,SysLog.class);
        System.out.println(obj);
    } 
    
    /** 
    * 
    * Method: ToList(String str, Class<T> t) 
    * 
    */ 
    @Test
    public void testToList() throws Exception {
        /*ArrayList<SysLog> List = new ArrayList<>();
        for (int i=0;i<3;i++)
        {
            SysLog log = new SysLog();
            log.setUserName("jack"+i);
            log.setAction("add");
            log.setEvent("insert");
            log.setHost("127.0.0.1");
            log.setInsertTime(LocalDateTime.now());
            List.add(log);
        }
        String strJson = Json.ToJSONString(List);
    
        List<SysLog> List2 = Json.ToList(strJson,SysLog.class);
    
        System.out.println(List2);*/
    
        ArrayList<Media> listMedia = new ArrayList<>();
        for(int i=0;i<3;i++){
            Media media = new Media();
            media.setId(i);
            media.setTypeId(i);
            media.setMemo("test"+i);
            media.setPicUrl("/pic/test"+i+".jpg");
            listMedia.add(media);
        }
        News news = new News();
        news.setAuthor("jack");
        news.setContents("this is a test for news");
        news.setTitle("news title");
        news.setListMedia(listMedia);
    
        String strJson = Json.ToJSONString(news);
    
        News news2 = Json.ToObject(strJson,News.class);
        System.out.println(news2);
    }
    
    
        /**
    * 
    * Method: ToMap(String str) 
    * 
    */ 
    @Test
    public void testToMap() throws Exception { 
    //TODO: Test goes here... 
    } 
    
    
    }

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