JackSonUtil JSONArray转换工具

客官°小女子只卖身不卖艺 2022-05-11 02:06 107阅读 0赞

import com.fasterxml.jackson.core.type.TypeReference;
    import com.fasterxml.jackson.databind.ObjectMapper;
    
    public final class JacksonUtil {
        public static ObjectMapper objectMapper;
    
        /**
         * 使用泛型方法，把json字符串转换为相应的JavaBean对象。
         * (1)转换为普通JavaBean：readValue(json,Student.class)
         * (2)转换为List,如List<Student>,将第二个参数传递为Student
         * [].class.然后使用Arrays.asList();方法把得到的数组转换为特定类型的List
         *
         * @param jsonStr
         * @param valueType
         * @return
         */
        public static <T> T readValue(String jsonStr, Class<T> valueType) {
            if (objectMapper == null) {
                objectMapper = new ObjectMapper();
            }
    
            try {
                return objectMapper.readValue(jsonStr, valueType);
            } catch (Exception e) {
                e.printStackTrace();
            }
    
            return null;
        }
    
        /**
         * json数组转List
         * @param jsonStr
         * @param valueTypeRef
         * @return
         */
        public static <T> T readValue(String jsonStr, TypeReference<T> valueTypeRef){
            if (objectMapper == null) {
                objectMapper = new ObjectMapper();
            }
    
            try {
                return objectMapper.readValue(jsonStr, valueTypeRef);
            } catch (Exception e) {
                e.printStackTrace();
            }
    
            return null;
        }
    
        /**
         * 把JavaBean转换为json字符串
         *
         * @param object
         * @return
         */
        public static String toJSon(Object object) {
            if (objectMapper == null) {
                objectMapper = new ObjectMapper();
            }
    
            try {
                return objectMapper.writeValueAsString(object);
            } catch (Exception e) {
                e.printStackTrace();
            }
    
            return null;
        }
    
    }