json-lib 与Jackson性能对比

由于打算采用redis缓存接收到的数据，而接收到的数据解析后的结果是一个Map，希望利用redis缓存该Map，而redis中能接收的数据类型为String与byte数组，考虑再三，决定采用String存储，对于Map转String存储，以及反转，我首先想到的是json字符串的方式存储（虽然后来与一位朋友沟通后表示google的protobuf可能性能与内存占用上可能更佳），下面是测试结果：
Map大小为13，占1548个字节，单线程转换10000次，并反转，结果如下：

----------json-lib---------------
Map转字符串耗时:5540.254697
字符串转Map耗时:14268.4411
--------Jackson------------------
Map转字符串耗时:962.843043
字符串转Map耗时:530.927814

以下为测试代码：
MapToJson.java

package com.json.test;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.JsonConfig;

import com.fasterxml.jackson.databind.ObjectMapper;

public class MapToJson {
/**
* 模拟的OBD数据上报(10数据+3基站)
*/
public static Map<String,Object> obdDataMap;
public static List<String> obdDataList = new ArrayList<String>();
public static ObjectMapper mapper = new ObjectMapper();

public static int COUNT = 10000;

public static JsonConfig jsonConfig;
static{
init();
mapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
jsonConfig = new JsonConfig();
jsonConfig.registerJsonValueProcessor(java.util.Date.class, new JsonDateValueProcessor());
jsonConfig.registerJsonValueProcessor(java.sql.Date.class, new JsonDateValueProcessor());
}
static void init(){
obdDataMap = new HashMap<String, Object>();
List<Map<String,Object>> dataList = new ArrayList<Map<String,Object>>();
Map<String,Object> dataMap = null;
Map<String,Object> obdMap = null;
for(int i=0;i<10;i++){
dataMap = new HashMap<String, Object>();
obdMap = new HashMap<String,Object>();
obdMap.put("GATHERTIME", new Date());
obdMap.put("PID_010B", 43);
obdMap.put("PID_010C", 784.25d);
obdMap.put("OBD_SPEED", 12);
obdMap.put("PID_010F", 53);
dataMap.put("obdData", obdMap);
dataList.add(dataMap);
}
for(int i=0;i<3;i++){
dataMap = new HashMap<String, Object>();
obdMap = new HashMap<String,Object>();
obdMap.put("CELL_ID", "22253");
obdMap.put("MOBILE_COUNTRY_CODE", "460");
obdMap.put("LOCATION_AREA_CODE", "22528");
obdMap.put("MOBILE_NETWORK_CODE", "0");
obdMap.put("SIGNAL_STRENGTH", "38");
dataMap.put("cellTowerData", obdMap);
dataList.add(dataMap);
}

obdDataMap.put("sourceData", dataList);
}

public static void mapToStr(){
long t0 = System.nanoTime();
JSONObject json = null;
for(int i=0;i<COUNT;i++){	//10000
json = JSONObject.fromObject(obdDataMap,jsonConfig);
obdDataList.add(json.toString());
//			System.out.println(json.toString().length());
}

long t1 = System.nanoTime();
System.out.println("Map转字符串耗时:"+(t1-t0)/1000000.0);
}
public static void mapToStr2() throws IOException{
long t0 = System.nanoTime();
String str = null;
for(int i =0;i<COUNT;i++){
str = mapper.writeValueAsString(obdDataMap);
obdDataList.add(str);
//			System.out.println(str);
}
long t1 = System.nanoTime();
System.out.println("Map转字符串耗时:"+(t1-t0)/1000000.0);
}

public static void strToMap(){
long t0 = System.nanoTime();
List<JSONObject> jsonArray = JSONArray.fromObject(obdDataList,jsonConfig);
Map<String,Object> map;
for(JSONObject obj:jsonArray){
map = (Map<String, Object>) obj;
//			System.out.println(map);
}
long t1 = System.nanoTime();
System.out.println("字符串转Map耗时:"+(t1-t0)/1000000.0);
}

public static void strToMap2() throws IOException{
long t0 = System.nanoTime();
Map<String,Object> map = null;
for(String str:obdDataList){
map = mapper.readValue(str, Map.class);
//			System.out.println(map);
}
long t1 = System.nanoTime();
System.out.println("字符串转Map耗时:"+(t1-t0)/1000000.0);
}

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
System.out.println("----------json-lib---------------");
mapToStr();
strToMap();
obdDataList.clear();
System.out.println("--------Jackson------------------");
mapToStr2();
strToMap2();
}

}

一个辅助类 JsonDateValueProcessor.java

package com.json.test;

import java.text.DateFormat;
import java.text.SimpleDateFormat;

import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonValueProcessor;

/****************************************************************************
* com.sides.pub.util JsonDateValueProcessor.java Created on 2013-9-16
* @Author: linfenliang
* @Description: 该类主要将日期类型（java.util.Date与java.sql.Date）格式化为yyyy-MM-dd HH:mm:ss字符串
* @Version: 1.0
***************************************************************************/
public class JsonDateValueProcessor implements JsonValueProcessor {
private static final DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
/**
* 将日期类型（java.util.Date与java.sql.Date）格式化为yyyy-MM-dd HH:mm:ss字符串
* @author linfenliang
*/
public JsonDateValueProcessor() {
super();
}

@Override
public Object processArrayValue(Object arg0, JsonConfig arg1) {
return process(arg0);
}

@Override
public Object processObjectValue(String arg0, Object arg1, JsonConfig arg2) {
return process(arg1);
}
private Object process(Object value) {
try {
if (value instanceof java.util.Date || value instanceof java.sql.Date) {
return dateFormat.format(value);
}
return value == null ? "" : value.toString();
} catch (Exception e) {
return "";
}
}
}