package com.admin.util;

import java.io.IOException;
import java.text.SimpleDateFormat;

import org.apache.commons.lang3.StringUtils;

import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * json工具类
 * 
 * @author chengdaolu
 * @date 2017年5月28日
 */
public class JsonUtil {

	private static final ObjectMapper json = new ObjectMapper()
			.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));

	public String toString(Object obj) throws JsonProcessingException {

		return obj == null ? "" : json.writeValueAsString(obj);

	}

	public static <T> T toObj(String str,Class<T> valueType)
			throws JsonParseException,JsonMappingException,IOException {
		if (StringUtils.isEmpty(str)) {
			return null;
		}
		return json.readValue(str,valueType);
	}

	public static <T> T toList(String str,TypeReference<T> valueTypeRef)
			throws JsonParseException,IOException {
		if (StringUtils.isEmpty(str) || null == valueTypeRef) {
			return null;
		}
		return json.readValue(str,valueTypeRef);
	}
}