一、新建一个项目，导入这两个jar包，下载见附件：

jackson-core-asl-1.9.12.jar

jackson-mapper-asl-1.9.12.jar

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二、新建一个工具类

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JsonMapper.java

package com.ebiz.logic.service.impl;

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

import org.apache.commons.lang3.StringUtils;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.DeserializationConfig;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion;
import org.codehaus.jackson.map.util.JSONPObject;
import org.codehaus.jackson.type.JavaType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.ebiz.framework.util.date.DateUtil;

/**
 * 简单封装Jackson，实现JSON String<->Java Object的Mapper.
 * 
 * 封装不同的输出风格, 使用不同的builder函数创建实例.
 * 
 */
public class JsonMapper {

	private static Logger logger = LoggerFactory.getLogger(JsonMapper.class);

	private ObjectMapper mapper;

	public JsonMapper(Inclusion inclusion) {
		mapper = new ObjectMapper();
		//设置输出时包含属性的风格
		mapper.setSerializationInclusion(inclusion);
		//设置输入时忽略在JSON字符串中存在但Java对象实际没有的属性
		mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
		//禁止使用int代表Enum的order()來反序列化Enum,非常危險
		mapper.configure(DeserializationConfig.Feature.FAIL_ON_NUMBERS_FOR_ENUMS, true);
	}

	/**
	 * 创建输出全部属性到Json字符串的Mapper.
	 */
	public static JsonMapper buildNormalMapper() {
		return new JsonMapper(Inclusion.ALWAYS);
	}

	/**
	 * 创建只输出非空属性到Json字符串的Mapper.
	 */
	public static JsonMapper buildNonNullMapper() {
		return new JsonMapper(Inclusion.NON_NULL);
	}

	/**
	 * 创建只输出初始值被改变的属性到Json字符串的Mapper.
	 */
	public static JsonMapper buildNonDefaultMapper() {
		return new JsonMapper(Inclusion.NON_DEFAULT);
	}

	/**
	 * 创建只输出非Null且非Empty(如List.isEmpty)的属性到Json字符串的Mapper.
	 */
	public static JsonMapper buildNonEmptyMapper() {
		return new JsonMapper(Inclusion.NON_EMPTY);
	}

	/**
	 * 如果对象为Null, 返回"null".
	 * 如果集合为空集合, 返回"[]".
	 */
	public String toJson(Object object) {

		try {
			return mapper.writeValueAsString(object);
		} catch (IOException e) {
			throw NestedException.wrap(e);
		}
	}

	/**
	 * 如果JSON字符串为Null或"null"字符串, 返回Null.
	 * 如果JSON字符串为"[]", 返回空集合.
	 * 
	 * 如需读取集合如List/Map, 且不是List<String>这种简单类型时,先使用函數constructParametricType构造类型.
	 * @see #constructParametricType(Class, Class...)
	 */
	public <T> T fromJson(String jsonString, Class<T> clazz) {
		if (StringUtils.isEmpty(jsonString)) {
			return null;
		}

		try {
			return mapper.readValue(jsonString, clazz);
		} catch (IOException e) {
			throw NestedException.wrap(e);
		}
	}

	/**
	 * 如果JSON字符串为Null或"null"字符串, 返回Null.
	 * 如果JSON字符串为"[]", 返回空集合.
	 * 
	 * 如需读取集合如List/Map, 且不是List<String>这种简单类型时,先使用函數constructParametricType构造类型.
	 * @see #constructParametricType(Class, Class...)
	 */
	@SuppressWarnings("unchecked")
	public <T> T fromJson(String jsonString, JavaType javaType) {
		if (StringUtils.isEmpty(jsonString)) {
			return null;
		}

		try {
			return (T) mapper.readValue(jsonString, javaType);
		} catch (IOException e) {
			throw NestedException.wrap(e);
		}
	}
	
	@SuppressWarnings("unchecked")
	public <T> T fromJson(String jsonString, Class<?> parametrized, Class<?>... parameterClasses) {
		return (T) this.fromJson(jsonString, constructParametricType(parametrized, parameterClasses));
	}
	
	@SuppressWarnings("unchecked")
	public <T> List<T> fromJsonToList(String jsonString, Class<T> classMeta){
		return (List<T>) this.fromJson(jsonString,constructParametricType(List.cl