java String转Json工具类

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 *
 * @className json处理工具
 */
public class JsonUtill {

　　 //json字符串转对象
    public static <T> T toObject(String json,Class<T> tClass){
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            return objectMapper.readValue(json,tClass);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
            return null;
        }
    }

　　 // 对象转json字符串
    public static String toString(Object json){
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            return objectMapper.writeValueAsString(json);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
            return null;
        }
    }

　　 // json数组转map对象
    public static <K,V> Map<K,V> toMap(String json,Map<K,V> map){
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            return objectMapper.readValue(json,map.getClass());
        } catch (JsonProcessingException e) {
            e.printStackTrace();
            return null;
        }
    }

　　 // json字符串转list对象
    public static <T> List<?> toList(String json,List<T> list){
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            return objectMapper.readValue(json,list.getClass());
        } catch (JsonProcessingException e) {
            e.printStackTrace();
            return null;
        }
    }

　　 // json 字符串转set对象
    public static <T> Set<T> toSet(String json, Set<T> set){
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            return objectMapper.readValue(json,set.getClass());
        } catch (JsonProcessingException e) {
            e.printStackTrace();
            return null;
        }
    }
}