【Utils】JsonUtil

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

/** *  Customized response structure of Tesco mall  */
public class JsonUtils {
    

    //  Definition jackson object 
    private static final ObjectMapper MAPPER = new ObjectMapper();

    /** *  Converts an object to json character string . * <p>Title: pojoToJson</p> * <p>Description: </p> * @param data * @return */
    public static String objectToJson(Object data) {
    
        try {
    
            String string = MAPPER.writeValueAsString(data);
            return string;
        } catch (JsonProcessingException e) {
    
            e.printStackTrace();
        }
        return null;
    }

    /** *  take json Result set converted to object  * * @param jsonData json data  * @param beanType  Object object type  * @return */
    public static <T> T jsonToPojo(String jsonData, Class<T> beanType) {
    
        try {
    
            T t = MAPPER.readValue(jsonData, beanType);
            return t;
        } catch (Exception e) {
    
            e.printStackTrace();
        }
        return null;
    }

    /** *  take json Data to pojo object list * <p>Title: jsonToList</p> * <p>Description: </p> * @param jsonData * @param beanType * @return */
    public static <T>List<T> jsonToList(String jsonData, Class<T> beanType) {
    
        JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType);
        try {
    
            List<T> list = MAPPER.readValue(jsonData, javaType);
            return list;
        } catch (Exception e) {
    
            e.printStackTrace();
        }

        return null;
    }

    /** *  hold json Convert to Map Tool method  * @param jsonData * @param keyType * @param valueType * @param <K> * @param <V> * @return */
    public static <K,V> Map<K,V> jsonToMap(String jsonData, Class<K> keyType,Class<V> valueType){
    
        JavaType javaType = MAPPER.getTypeFactory().constructMapType(Map.class,keyType,valueType);
        try {
    
            Map<K,V> map = MAPPER.readValue(jsonData,javaType);
            return map;
        } catch (JsonProcessingException e) {
    
            e.printStackTrace();
        }
        return null;
    }

}