关于Jackson的使用说明

概述

Jackson框架是基于Java平台的一套数据处理工具，被称为“最好的Java Json解析器”。

Jackson Home Page：https://github.com/FasterXML/jackson
Jackson Wiki：http://wiki.fasterxml.com/JacksonHome
Jackson doc: https://github.com/FasterXML/jackson-docs
Jackson Download Page：http://wiki.fasterxml.com/JacksonDownload

依赖Jackson的三个核心库

jackson-core-2.5.3.jar
jackson-annotations-2.5.3.jar
jackson-databind-2.5.3.jar

maven引用Jackson

<dependency>  

  <groupId>com.fasterxml.jackson.core</groupId>  
  <artifactId>jackson-core</artifactId>  
  <version>2.7.4</version>  
</dependency>  
  
<dependency>  
  <groupId>com.fasterxml.jackson.core</groupId>  
  <artifactId>jackson-annotations</artifactId>  
  <version>2.7.4</version>  
</dependency>  
  
<dependency>  
  <groupId>com.fasterxml.jackson.core</groupId>  
  <artifactId>jackson-databind</artifactId>  
  <version>2.7.4</version>  
</dependency> 

Jackson解析

package com.neusoft.bossAgent.utils;

import java.io.StringReader;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

@SuppressWarnings("unchecked")
public class JSONUtils {
	private static final ObjectMapper mapper = new ObjectMapper();
	private static final Logger log = LoggerFactory.getLogger(JSONUtils.class);

	static {
		mapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);//
		mapper.configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
		mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
		mapper.setSerializationInclusion(Include.NON_NULL);  
	}

	public static String toString(Object object) {
		String result = null;
		if (null == object) {
			return result;
		}
		try {
			result = mapper.writeValueAsString(object);
		} catch (JsonProcessingException e) {
			log.error("对象转换json字符串出错", e);
		}
		return result;
	}

	public static <T> T readValueFromString(Class<T> type, String value) {
		try {
			return (T) mapper.readValue(value, type);
		} catch (Exception e) {
			log.error("读取json字符串出错", e);
		}
		return null;
	}
}

以下图片为objectmapper的一些配置