com.vip.saturn.job.console.utils.JsonUtils Maven / Gradle / Ivy

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/**
 * Copyright 2016 vip.com.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 *  the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 * 
 **/

package com.vip.saturn.job.console.utils;

import java.text.SimpleDateFormat;
import java.util.List;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.ser.std.NullSerializer;
import org.codehaus.jackson.type.JavaType;
import org.codehaus.jackson.type.TypeReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Json Utils
 *
 * @author linzhaoming
 */
public class JsonUtils {

	private static final ObjectMapper mapper = new ObjectMapper();
	static Logger log = LoggerFactory.getLogger(JsonUtils.class);

	static {
		mapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
		mapper.getSerializerProvider().setNullKeySerializer(NullSerializer.instance);
	}

	private static ObjectMapper getObjectMapper() {
		return mapper;
	}

	/**
	 * 转换对象为JSON
	 *
	 * @param obj 待转换对象
	 * @return JSON字符串
	 */
	public static String toJSON(Object obj) {
		try {
			String value = getObjectMapper().writeValueAsString(obj);
			return value;
		} catch (Exception e) {
			log.error("msg=Fail at toJSON: ", e);
		}
		return "";
	}

	/**
	 * 从JSON转换为对象
	 *
	 * @param  转换的Java类型
	 * @param jsonStr JSON字符串
	 * @param type 指定类型
	 * @return 转换后的对象
	 */
	public static  T fromJSON(String jsonStr, Class type) {
		T result = null;
		try {
			result = getObjectMapper().readValue(jsonStr, type);
		} catch (Exception e) {
			log.error("msg=Fail at fromJSON: ", e);
		}
		return result;
	}

	/**
	 * 从JSON转换为对象
	 *
	 * @param jsonStr JSON字符串
	 * @param javaType 指定类型
	 * @return 转换后的对象
	 */
	public static  T fromJSON(String jsonStr, JavaType javaType) {
		T result = null;
		try {
			result = getObjectMapper().readValue(jsonStr, javaType);
		} catch (Exception e) {
			log.error("msg=Fail at fromJSON: ", e);
		}
		return result;
	}

	public static  T fromJSON(String jsonStr, TypeReference type) {
		T result = null;
		try {
			result = getObjectMapper().readValue(jsonStr, type);
		} catch (Exception e) {
			log.error("msg=Fail at fromJSON: ", e);
		}
		return result;
	}

	public static  JavaType constructListParametricType(Class contentClass) throws ClassNotFoundException {
		return mapper.getTypeFactory().constructParametricType(List.class, Class.forName(contentClass.getName()));
	}

}