package com.plum.core.utils;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;

/**
 * Json转换工具
 *
 * Created by G_dragon on 2015/7/24.
 */
public class JacksonJsonUtil {
    private static ObjectMapper mapper;

    /**
     * 获取ObjectMapper实例
     * @param createNew 方式：true，新实例；false,存在的mapper实例
     * @return
     */
    public static synchronized ObjectMapper getMapperInstance(boolean createNew) {
        if (createNew) {
            return new ObjectMapper();
        } else if (mapper == null) {
            mapper = new ObjectMapper();
        }
        return mapper;
    }

    /**
     * 将java对象转换成json字符串
     * @param obj 准备转换的对象
     * @return json字符串
     * @throws Exception
     */
    public static String beanToJson(Object obj) throws Exception {
        try {
            ObjectMapper objectMapper = getMapperInstance(false);
            String json =objectMapper.writeValueAsString(obj);
            return json;
        } catch (Exception e) {
            throw new Exception(e.getMessage());
        }
    }

    /**
     * 将java对象转换成json字符串
     * @param obj 准备转换的对象
     * @param createNew ObjectMapper实例方式:true，新实例;false,存在的mapper实例
     * @return json字符串
     * @throws Exception
     */
    public static String beanToJson(Object obj,Boolean createNew) throws Exception {
        try {
            ObjectMapper objectMapper = getMapperInstance(createNew);
            String json =objectMapper.writeValueAsString(obj);
            return json;
        } catch (Exception e) {
            throw new Exception(e.getMessage());
        }
    }

    /**
     * 将json字符串转换成java对象
     * @param json 准备转换的json字符串
     * @param cls  准备转换的类
     * @param createNew ObjectMapper实例方式:true，新实例;false,存在的mapper实例
     * @return
     * @throws Exception
     */
    public static Object jsonToBean(String json, Class<?> cls,Boolean createNew) throws Exception {
        try {
            ObjectMapper objectMapper = getMapperInstance(createNew);
            Object vo = objectMapper.readValue(json, cls);
            return vo;
        } catch (Exception e) {
            throw new Exception(e.getMessage());
        }
    }

    /**
     * 将json字符串转换成java对象
     *
     * @param json 准备转换的json字符串
     * @param cls  准备转换的类
     * @param <T>
     * @return
     */
    public static <T> T jsonToBean(String json, Class<T> cls){
        ObjectMapper objectMapper = getMapperInstance(true);
        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        T vo = null;
        try {
            vo = objectMapper.readValue(json, cls);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return vo;
    }
}