hutool工具-----JSON工具-JSONUtil

秒速五厘米 2023-09-30 08:56 17阅读 0赞

### 文章预览： ###

*  JSONUtil
 *  介绍
 *  使用
 *   *  1、JSON字符串创建
     *  2、JSON字符串解析
     *  3、XML字符串转换为JSON
     *  4、JSON转换为XML
     *  5、 JSON转Bean

# JSONUtil #

# 介绍 #

JSONUtil是针对JSONObject和JSONArray的静态快捷方法集合，在之前的章节我们已经介绍了一些工具方法，在本章节我们将做一些补充。

# 使用 #

## 1、JSON字符串创建 ##

JSONUtil.toJsonStr可以将任意对象（Bean、Map、集合等）直接转换为JSON字符串。 如果对象是有序的Map等对象，则转换后的JSON字符串也是有序的。

/**
         * 转换为JSON字符串
         * <p>
         * 被转为JSON的对象
         *
         * @return JSON字符串
         */
        @Test
        void toJsonStrTest() {
        
            //map
            SortedMap<Object, Object> sortedMap = new TreeMap<Object, Object>() {
        
                private static final long serialVersionUID = 1L;
                {
        
                    put("attributes", "a");
                    put("b", "b");
                    put("c", "c");
                }
            };
            //对象
            Student beanString = new Student(1, 1, 1, "张三");
    
            //集合
            List<Student> list = new ArrayList<>();
            list.add(new Student(1, 1, 1, "张三"));
            list.add(new Student(1, 1, 2, "李四"));
            list.add(new Student(1, 1, 3, "王五"));
    
            System.out.println("JSONUtil.toJsonStr(beanString) = " + JSONUtil.toJsonStr(beanString));
            System.out.println("JSONUtil.toJsonStr(sortedMap) = " + JSONUtil.toJsonStr(sortedMap));
            System.out.println("JSONUtil.toJsonStr(list) = " + JSONUtil.toJsonStr(list));
        }

结果

JSONUtil.toJsonStr(beanString) = {
        "gradeId":0,"studentId":1,"termId":1,"classId":1,"name":"张三"}
    JSONUtil.toJsonStr(sortedMap) = {
        "attributes":"a","b":"b","c":"c"}
    JSONUtil.toJsonStr(list) = [{
        "gradeId":0,"studentId":1,"termId":1,"classId":1,"name":"张三"},
    {
        "gradeId":0,"studentId":2,"termId":1,"classId":1,"name":"李四"},
    {
        "gradeId":0,"studentId":3,"termId":1,"classId":1,"name":"王五"}]

如果我们想获得格式化后的JSON，则：

JSONUtil.toJsonPrettyStr(object);
    
    System.out.println("JSONUtil.toJsonPrettyStr(sortedMap) = "
     + JSONUtil.toJsonPrettyStr(sortedMap));

结果

JSONUtil.toJsonPrettyStr(sortedMap) = {
        
        "attributes": "a",
        "b": "b",
        "c": "c"
    }

## 2、JSON字符串解析 ##

/**
         * JSON字符串转JSONObject对象
         * <p>
         * JSON字符串
         *
         * @return JSONObject
         */
        @Test
        void Test() {
        
            String html = "{\"name\":\"Something must have been changed since you leave\"}";
            JSONObject jsonObject = JSONUtil.parseObj(html);
            System.out.println("jsonObject.getStr(\"name\") = " + jsonObject.getStr("name"));
        }

结果

jsonObject.getStr("name") = Something must have been changed since you leave

## 3、XML字符串转换为JSON ##

/**
         * XML字符串转为JSONObject
         *
         *  XML字符串
         * @return JSONObject
         */
        @Test
        void parseFromXmlTest() {
        
            String s = "<sfzh>123</sfzh><sfz>456</sfz><name>aa</name><gender>1</gender>";
            JSONObject json = JSONUtil.parseFromXml(s);
            System.out.println("json.get(\"sfzh\") = " + json.get("sfzh"));
            System.out.println("json.get(\"name\") = " + json.get("name"));
    
        }

结果

json.get("sfzh") = 123
    json.get("name") = aa

## 4、JSON转换为XML ##

/**
         * 转换为XML字符串
         *
         * @param json JSON
         * @return XML字符串
         */
        @Test
        void toXmlStrTest() {
        
            final JSONObject put = JSONUtil.createObj()
                    .set("aaa", "你好")
                    .set("键2", "test");
    
    // <aaa>你好</aaa><键2>test</键2>
            final String s = JSONUtil.toXmlStr(put);
            System.out.println("s = " + s);
    
        }

结果

s = <aaa>你好</aaa><键2>test</键2>

## 5、 JSON转Bean ##

我们先定义两个较为复杂的Bean（包含泛型）

@Data
        public class ADT {
        
            private List<String> BookingCode;
        }
    
        @Data
        public class Price {
        
            private List<List<ADT>> ADT;
        }
    
        /**
         * JSON字符串转为实体类对象，转换异常将被抛出
         *
         * @param <T>        Bean类型
         * @param jsonString JSON字符串
         * @param beanClass  实体类对象
         * @return 实体类对象
         * @since 3.1.2
         */
        @Test
        void toBeanTest() {
        
            String json = "{\"ADT\":[[{\"BookingCode\":[\"N\",\"N\"]}]]}";
            Price price = JSONUtil.toBean(json, Price.class);
            System.out.println("price = " + price);
        }