常见Bean拷贝框架的性能有哪些区别
本篇内容介绍了"常见Bean拷贝框架的性能有哪些区别"的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
I.背景
当业务量不大时，不管选择哪个框架都没什么问题，只要功能支持就ok了；但是当数据量大的时候，可能就需要考虑性能问题了；再实际的项目中，正好遇到了这个问题，不仅慢，还发现会有锁竞争，这特么就尼普了
项目中使用的是Spring的 BeanUtils， 版本 3.2.4.RELEASE， 版本相对较老，主要问题在于org.springframework.beans.CachedIntrospectionResults.forClass
/** * Create CachedIntrospectionResults for the given bean class. *We don't want to use synchronization here. Object references are atomic, * so we can live with doing the occasional unnecessary lookup at startup only. * @param beanClass the bean class to analyze * @return the corresponding CachedIntrospectionResults * @throws BeansException in case of introspection failure */static CachedIntrospectionResults forClass(Class beanClass) throws BeansException { CachedIntrospectionResults results; Object value; synchronized (classCache) { value = classCache.get(beanClass); } if (value instanceof Reference) { Reference ref = (Reference) value; results = (CachedIntrospectionResults) ref.get(); } else { results = (CachedIntrospectionResults) value; } if (results == null) { if (ClassUtils.isCacheSafe(beanClass, CachedIntrospectionResults.class.getClassLoader()) || isClassLoaderAccepted(beanClass.getClassLoader())) { results = new CachedIntrospectionResults(beanClass); synchronized (classCache) { classCache.put(beanClass, results); } } else { if (logger.isDebugEnabled()) { logger.debug("Not strongly caching class [" + beanClass.getName() + "] because it is not cache-safe"); } results = new CachedIntrospectionResults(beanClass); synchronized (classCache) { classCache.put(beanClass, new WeakReference
(results)); } } } return results;}
看上面的实现，每次获取value都加了一个同步锁，而且还是锁的全局的classCache，这就有些过分了啊，微妙的是这段代码注释，谷歌翻译之后为
我们不想在这里使用同步。 对象引用是原子的，因此我们可以只在启动时进行偶尔的不必要查找。
这意思大概是说我就在启动的时候用一下，并不会频繁的使用，所以使用了同步代码块也问题不大...
但是在BeanUtils#copyProperties中就蛋疼了，每次都会执行这个方法，扎心了
当然我们现在一般用的Spring5+了，这段代码也早就做了改造了，新版的如下，不再存在上面的这个并发问题了
/** * Create CachedIntrospectionResults for the given bean class. * @param beanClass the bean class to analyze * @return the corresponding CachedIntrospectionResults * @throws BeansException in case of introspection failure */@SuppressWarnings("unchecked")static CachedIntrospectionResults forClass(Class beanClass) throws BeansException { CachedIntrospectionResults results = strongClassCache.get(beanClass); if (results != null) { return results; } results = softClassCache.get(beanClass); if (results != null) { return results; } results = new CachedIntrospectionResults(beanClass); ConcurrentMap, CachedIntrospectionResults> classCacheToUse; if (ClassUtils.isCacheSafe(beanClass, CachedIntrospectionResults.class.getClassLoader()) || isClassLoaderAccepted(beanClass.getClassLoader())) { classCacheToUse = strongClassCache; } else { if (logger.isDebugEnabled()) { logger.debug("Not strongly caching class [" + beanClass.getName() + "] because it is not cache-safe"); } classCacheToUse = softClassCache; } CachedIntrospectionResults existing = classCacheToUse.putIfAbsent(beanClass, results); return (existing != null ? existing : results);} II. 不同框架使用姿势
接下来我们看一下几种常见的bean拷贝框架的使用姿势，以及对比测试
1. apache BeanUtils
阿里规范中，明确说明了，不要使用它，idea安装阿里的代码规范插件之后，会有提示
使用姿势比较简单，引入依赖
commons-beanutils commons-beanutils 1.9.4
属性拷贝
@Componentpublic class ApacheCopier { public T copy(K source, Class target) throws IllegalAccessException, InstantiationException, InvocationTargetException { T res = target.newInstance(); // 注意，第一个参数为target，第二个参数为source // 与其他的正好相反 BeanUtils.copyProperties(res, source); return res; }} 2. cglib BeanCopier
cglib是通过动态代理的方式来实现属性拷贝的，与上面基于反射实现方式存在本质上的区别，这也是它性能更优秀的主因
在Spring环境下，一般不需要额外的引入依赖；或者直接引入spring-core
org.springframework spring-core 5.2.8.RELEASE compile
属性拷贝
@Componentpublic class SpringCglibCopier { /** * cglib 对象转换 * * @param source * @param target * @param * @param * @return * @throws IllegalAccessException * @throws InstantiationException */ public T copy(K source, Class target) throws IllegalAccessException, InstantiationException { BeanCopier copier = BeanCopier.create(source.getClass(), target, false); T res = target.newInstance(); copier.copy(source, res, null); return res; }} 当然也可以直接使用纯净版的cglib，引入依赖
cglib cglib 3.3.0
使用姿势和上面一模一样
@Componentpublic class PureCglibCopier { /** * cglib 对象转换 * * @param source * @param target * @param * @param * @return * @throws IllegalAccessException * @throws InstantiationException */ public T copy(K source, Class target) throws IllegalAccessException, InstantiationException { BeanCopier copier = BeanCopier.create(source.getClass(), target, false); T res = target.newInstance(); copier.copy(source, res, null); return res; }} 3. spring BeanUtils
这里使用的是spring 5.2.1.RELEASE， 就不要拿3.2来使用了，不然并发下的性能实在是感人
基于内省+反射，借助getter/setter方法实现属性拷贝，性能比apache高
核心依赖
org.springframework spring-beans 5.2.1.RELEASE compile
属性拷贝
@Componentpublic class SpringBeanCopier { /** * 对象转换 * * @param source * @param target * @param * @param * @return * @throws IllegalAccessException * @throws InstantiationException */ public T copy(K source, Class target) throws IllegalAccessException, InstantiationException { T res = target.newInstance(); BeanUtils.copyProperties(source, res); return res; }} 4. hutool BeanUtil
hutool 提供了很多的java工具类，从测试效果来看它的性能比apache会高一点，当低于spring
引入依赖
cn.hutool hutool-core 5.6.0
使用姿势
@Componentpublic class HutoolCopier { /** * bean 对象转换 * * @param source * @param target * @param * @param * @return */ public T copy(K source, Class target) throws Exception { return BeanUtil.toBean(source, target); }} 5. MapStruct
MapStruct 性能更强悍了，缺点也比较明显，需要声明bean的转换接口，自动代码生成的方式来实现拷贝，性能媲美直接的get/set
引入依赖
org.mapstruct mapstruct 1.4.2.Final org.mapstruct mapstruct-processor 1.4.2.Final
使用姿势
@Mapperpublic interface MapStructCopier { Target copy(Source source);}@Componentpublic class MapsCopier { private MapStructCopier mapStructCopier = Mappers.getMapper(MapStructCopier.class); public Target copy(Source source, Class target) { return mapStructCopier.copy(source); }} 缺点也比较明显，需要显示的接口转换声明
6. 测试
定义两个Bean，用于转换测试，两个bean的成员属性名，类型完全一致
@Datapublic class Source { private Integer id; private String user_name; private Double price; private List ids; private BigDecimal marketPrice;}@Datapublic class Target { private Integer id; private String user_name; private Double price; private List ids; private BigDecimal marketPrice;} 6.1 功能测试
private Random random = new Random();public Source genSource() { Source source = new Source(); source.setId(random.nextInt()); source.setIds(Arrays.asList(random.nextLong(), random.nextLong(), random.nextLong())); source.setMarketPrice(new BigDecimal(random.nextFloat())); source.setPrice(random.nextInt(120) / 10.0d); source.setUser_name("一灰灰Blog"); return source;} private void copyTest() throws Exception { Source s = genSource(); Target ta = apacheCopier.copy(s, Target.class); Target ts = springBeanCopier.copy(s, Target.class); Target tc = springCglibCopier.copy(s, Target.class); Target tp = pureCglibCopier.copy(s, Target.class); Target th = hutoolCopier.copy(s, Target.class); Target tm = mapsCopier.copy(s, Target.class); System.out.println("source:\t" + s + "\napache:\t" + ta + "\nspring:\t" + ts + "\nsCglib:\t" + tc + "\npCglib:\t" + tp + "\nhuTool:\t" + th + "\nmapStruct:\t" + tm);}输出结果如下，满足预期
source: Source(id=1337715455, user_name=一灰灰Blog, price=7.1, ids=[7283949433132389385, 3441022909341384204, 8273318310870260875], marketPrice=0.04279220104217529296875)apache: Target(id=1337715455, user_name=一灰灰Blog, price=7.1, ids=[7283949433132389385, 3441022909341384204, 8273318310870260875], marketPrice=0.04279220104217529296875)spring: Target(id=1337715455, user_name=一灰灰Blog, price=7.1, ids=[7283949433132389385, 3441022909341384204, 8273318310870260875], marketPrice=0.04279220104217529296875)sCglib: Target(id=1337715455, user_name=一灰灰Blog, price=7.1, ids=[7283949433132389385, 3441022909341384204, 8273318310870260875], marketPrice=0.04279220104217529296875)pCglib: Target(id=1337715455, user_name=一灰灰Blog, price=7.1, ids=[7283949433132389385, 3441022909341384204, 8273318310870260875], marketPrice=0.04279220104217529296875)huTool: Target(id=1337715455, user_name=一灰灰Blog, price=7.1, ids=[7283949433132389385, 3441022909341384204, 8273318310870260875], marketPrice=0.04279220104217529296875)mapStruct: Target(id=1337715455, user_name=一灰灰Blog, price=7.1, ids=[7283949433132389385, 3441022909341384204, 8273318310870260875], marketPrice=0.04279220104217529296875)
6.2 性能测试
接下来我们关注一下不同的工具包，实现属性拷贝的性能对比情况如何
public void test() throws Exception { // 第一次用于预热 autoCheck(Target2.class, 10000); autoCheck(Target2.class, 10000); autoCheck(Target2.class, 10000_0); autoCheck(Target2.class, 50000_0); autoCheck(Target2.class, 10000_00);}private void autoCheck(Class target, int size) throws Exception { StopWatch stopWatch = new StopWatch(); runCopier(stopWatch, "apacheCopier", size, (s) -> apacheCopier.copy(s, target)); runCopier(stopWatch, "springCglibCopier", size, (s) -> springCglibCopier.copy(s, target)); runCopier(stopWatch, "pureCglibCopier", size, (s) -> pureCglibCopier.copy(s, target)); runCopier(stopWatch, "hutoolCopier", size, (s) -> hutoolCopier.copy(s, target)); runCopier(stopWatch, "springBeanCopier", size, (s) -> springBeanCopier.copy(s, target)); runCopier(stopWatch, "mapStruct", size, (s) -> mapsCopier.copy(s, target)); System.out.println((size / 10000) + "w -------- cost: " + stopWatch.prettyPrint());}private void runCopier(StopWatch stopWatch, String key, int size, CopierFunc func) throws Exception { stopWatch.start(key); for (int i = 0; i < size; i++) { Source s = genSource(); func.apply(s); } stopWatch.stop();}@FunctionalInterfacepublic interface CopierFunc { T apply(Source s) throws Exception;} 输出结果如下
1w -------- cost: StopWatch '': running time = 583135900 ns---------------------------------------------ns % Task name---------------------------------------------488136600 084% apacheCopier009363500 002% springCglibCopier009385500 002% pureCglibCopier053982900 009% hutoolCopier016976500 003% springBeanCopier005290900 001% mapStruct10w -------- cost: StopWatch '': running time = 5607831900 ns---------------------------------------------ns % Task name---------------------------------------------4646282100 083% apacheCopier096047200 002% springCglibCopier093815600 002% pureCglibCopier548897800 010% hutoolCopier169937400 003% springBeanCopier052851800 001% mapStruct50w -------- cost: StopWatch '': running time = 27946743000 ns---------------------------------------------ns % Task name---------------------------------------------23115325200 083% apacheCopier481878600 002% springCglibCopier475181600 002% pureCglibCopier2750257900 010% hutoolCopier855448400 003% springBeanCopier268651300 001% mapStruct100w -------- cost: StopWatch '': running time = 57141483600 ns---------------------------------------------ns % Task name---------------------------------------------46865332600 082% apacheCopier1019163600 002% springCglibCopier1033701100 002% pureCglibCopier5897726100 010% hutoolCopier1706155900 003% springBeanCopier619404300 001% mapStruct
| - | 1w | 10w | 50w | 100w |
|---|---|---|---|---|
| apache | 0.488136600s / 084% | 4.646282100s / 083% | 23.115325200s / 083% | 46.865332600s / 083% |
| spring cglib | 0.009363500s / 002% | 0.096047200s / 002% | 0.481878600s / 002% | 1.019163600s / 002% |
| pure cglibg | 0.009385500s / 002% | 0.093815600s / 002% | 0.475181600s / 002% | 1.033701100s / 002% |
| hutool | 0.053982900s / 009% | 0.548897800s / 010% | 2.750257900s / 010% | 5.897726100s / 010% |
| spring | 0.016976500s / 003% | 0.169937400s / 003% | 0.855448400s / 003% | 1.706155900s / 003% |
| mapstruct | 0.005290900s / 001% | 0.052851800s / 001% | 0.268651300s / 001% | 0.619404300s / 001% |
| total | 0.583135900s | 5.607831900s | 27.946743000s | 57.141483600s |
上面的测试中，存在一个不同的变量，即不是用相同的source对象来测试不同的工具转换情况，但是这个不同并不会太影响不同框架的性能对比，基本上从上面的运行结果来看
mapstruct, cglib, spring 表现最好
apache 表现最差
基本趋势相当于:
apache -> 10 * hutool -> 28 * spring -> 45 * cglib -> 83 * mapstruct
如果我们需要实现简单的bean拷贝，选择cglib或者spring的是个不错选择
"常见Bean拷贝框架的性能有哪些区别"的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注网站，小编将为大家输出更多高质量的实用文章！
