Jackson常用工具类

原创转载请注明出处：https://www.cnblogs.com/agilestyle/p/11983194.html

Demo

 package org.fool.util;

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

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

 public class JsonUtils {
     private static final ObjectMapper MAPPER = new ObjectMapper();

     public static String objectToJson(Object data) {
         try {
             String result = MAPPER.writeValueAsString(data);
             return result;
         } catch (JsonProcessingException e) {
             e.printStackTrace();
         }
         return null;
     }

     public static <T> T jsonToBean(String jsonData, Class<T> beanType) {
         try {
             T result = MAPPER.readValue(jsonData, beanType);
             return result;
         } catch (Exception e) {
             e.printStackTrace();
         }

         return null;
     }

     public static <T> List<T> jsonToList(String jsonData, Class<T> beanType) {
         JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType);

         try {
             List<T> resultList = MAPPER.readValue(jsonData, javaType);
             return resultList;
         } catch (Exception e) {
             e.printStackTrace();
         }

         return null;
     }

     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> resultMap = MAPPER.readValue(jsonData, javaType);
             return resultMap;
         } catch (Exception e) {
             e.printStackTrace();
         }

         return null;
     }
 }