工具类-JsonUtils

package com.yqq.utils;

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;

/**
* 自定义响应结构
*/
public class JsonUtils {

   // 定义jackson对象
   private static final ObjectMapper MAPPER = new ObjectMapper();

   /**
    * 将对象转换成json字符串。
    * <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;
   }
   
   /**
    * 将json结果集转化为对象
    * 
    * @param jsonData json数据
    * @param beanType 对象中的object类型
    * @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;
   }
   
   /**
    * 将json数据转换成pojo对象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;
   }

   public static Map jsonToMap(String jsonData,Class beanType){
       JavaType javaType = MAPPER.getTypeFactory().constructParametricType(Map.class,String.class,beanType);
       try{
           Map map = MAPPER.readValue(jsonData, javaType);
           return map;
       }catch(Exception e){
           e.printStackTrace();
       }
       return null;
   }
   
}