Bean拷貝工具類性能比較

引言

幾年前做過一個項目，接入新的api接口。爲了和api實現解耦，決定將api返回的實體類在本地也建一個。這樣做有兩個好處

可以在api變更字段的時候保持應用穩定性
可以對返回的實體的屬性做處理，以提高可讀性。例如接口返回long類型的時間戳，則將該字段在本地實體類中對應字段設置爲date類型方便使用。

大致是這樣的一個應用場景。當時剛畢業，充斥的都是A.setName(B.getName)這種類型的代碼。當字段非常多的時候看起來非常臃腫，最重要的給人感覺不優雅。

再給我一次機會

如果上天再給我一次機會，我會跟他說，我有四種工具類可以優雅的解決這個問題。
分別是

org.apache.commons.beanutils.PropertyUtils.copyProperties
org.apache.commons.beanutils.BeanUtils.copyProperties
org.springframework.beans.BeanUtils.copyProperties
net.sf.cglib.beans.BeanCopier

Talk is cheap, show me code

定義SourceBean

package com.zhaoyangwoo.model;

/**

Created by john on 16/7/28.
*/

public class SourceBean {

<span class="hljs-keyword">private</span> Integer age;

<span class="hljs-keyword">private</span> String title;

<span class="hljs-keyword">private</span> String source;

<span class="hljs-keyword">private</span> Boolean eat;

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-title">SourceBean</span><span class="hljs-params">(Integer i, String name, Boolean eat, String source)</span> </span>{
    <span class="hljs-keyword">this</span>.age = i;
    <span class="hljs-keyword">this</span>.title = name;
    <span class="hljs-keyword">this</span>.eat = eat;
    <span class="hljs-keyword">this</span>.source = source;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setAge</span><span class="hljs-params">(Integer age)</span> </span>{
    <span class="hljs-keyword">this</span>.age = age;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> String <span class="hljs-title">getTitle</span><span class="hljs-params">()</span> </span>{
    <span class="hljs-keyword">return</span> title;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setTitle</span><span class="hljs-params">(String title)</span> </span>{
    <span class="hljs-keyword">this</span>.title = title;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> Boolean <span class="hljs-title">getEat</span><span class="hljs-params">()</span> </span>{
    <span class="hljs-keyword">return</span> eat;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setEat</span><span class="hljs-params">(Boolean eat)</span> </span>{
    <span class="hljs-keyword">this</span>.eat = eat;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> String <span class="hljs-title">getSource</span><span class="hljs-params">()</span> </span>{
    <span class="hljs-keyword">return</span> source;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setSource</span><span class="hljs-params">(String source)</span> </span>{
    <span class="hljs-keyword">this</span>.source = source;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> Integer <span class="hljs-title">getAge</span><span class="hljs-params">()</span> </span>{
    <span class="hljs-keyword">return</span> age;
}

}

定義DesBean

package com.zhaoyangwoo.model;

/**

Created by john on 16/7/28.
*/

public class DstBean {

<span class="hljs-keyword">private</span> Integer age;

<span class="hljs-keyword">private</span> String title;

<span class="hljs-keyword">private</span> Boolean eat;

<span class="hljs-keyword">private</span> String self;

<span class="hljs-function"><span class="hljs-keyword">public</span> String <span class="hljs-title">getSelf</span><span class="hljs-params">()</span> </span>{
    <span class="hljs-keyword">return</span> self;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setSelf</span><span class="hljs-params">(String self)</span> </span>{
    <span class="hljs-keyword">this</span>.self = self;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> Integer <span class="hljs-title">getAge</span><span class="hljs-params">()</span> </span>{
    <span class="hljs-keyword">return</span> age;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setAge</span><span class="hljs-params">(Integer age)</span> </span>{
    <span class="hljs-keyword">this</span>.age = age;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> String <span class="hljs-title">getTitle</span><span class="hljs-params">()</span> </span>{
    <span class="hljs-keyword">return</span> title;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setTitle</span><span class="hljs-params">(String title)</span> </span>{
    <span class="hljs-keyword">this</span>.title = title;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> Boolean <span class="hljs-title">getEat</span><span class="hljs-params">()</span> </span>{
    <span class="hljs-keyword">return</span> eat;
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setEat</span><span class="hljs-params">(Boolean eat)</span> </span>{
    <span class="hljs-keyword">this</span>.eat = eat;
}

}

測試函數

package com.zhaoyangwoo.biz;

import com.zhaoyangwoo.model.DstBean;
import com.zhaoyangwoo.model.SourceBean;
import net.sf.cglib.beans.BeanCopier;

/**

Created by john on 16/7/28.
*/
public class BeanCopyMain {

private static BeanCopier beanCopier = BeanCopier.create(SourceBean.class, DstBean.class, false);

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">main</span><span class="hljs-params">(String[] args)</span> <span class="hljs-keyword">throws</span> Exception </span>{

    Integer[] times = {<span class="hljs-number">10000</span>, <span class="hljs-number">1000</span>, <span class="hljs-number">10</span>};

    <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i &lt; times.length; i++) {

        Integer time = times[i];
        doCopy(time, (x, y) -&gt; org.apache.commons.beanutils.PropertyUtils.copyProperties(y, x), <span class="hljs-string">"org.apache.commons.beanutils.PropertyUtils.copyProperties"</span>);
        doCopy(time, (x, y) -&gt; org.apache.commons.beanutils.BeanUtils.copyProperties(y, x), <span class="hljs-string">"org.apache.commons.beanutils.BeanUtils.copyProperties"</span>);
        doCopy(time, (x, y) -&gt; org.springframework.beans.BeanUtils.copyProperties(y, x), <span class="hljs-string">"org.springframework.beans.BeanUtils.copyProperties"</span>);
        doCopy(time, (x, y) -&gt; beanCopier.copy(x, y, <span class="hljs-keyword">null</span>), <span class="hljs-string">"net.sf.cglib.beans.BeanCopier.copy"</span>);
        doCopy(time, (x, y) -&gt; {
            y.setEat(x.getEat());
            y.setTitle(x.getTitle());
            y.setAge(x.getAge());
        }, <span class="hljs-string">"getter/setter"</span>);
    }
}

<span class="hljs-function"><span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">doCopy</span><span class="hljs-params">(Integer time, BeanCopy beanCopy, String type)</span> <span class="hljs-keyword">throws</span> Exception </span>{
    <span class="hljs-keyword">long</span> startTime = System.currentTimeMillis();
    <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> j = <span class="hljs-number">0</span>; j &lt; time; j++) {
        SourceBean sourceBean = <span class="hljs-keyword">new</span> SourceBean(j, <span class="hljs-string">"source"</span> + j, <span class="hljs-keyword">false</span>, <span class="hljs-string">"abc"</span>);
        DstBean dstBean = <span class="hljs-keyword">new</span> DstBean();
        beanCopy.copy(sourceBean, dstBean);
    }
    System.out.printf(<span class="hljs-string">"執行%d次用時%dms---------%s%n"</span>, time, System.currentTimeMillis() - startTime, type);
}

<span class="hljs-class"><span class="hljs-keyword">interface</span> <span class="hljs-title">BeanCopy</span> </span>{
    <span class="hljs-function"><span class="hljs-keyword">void</span> <span class="hljs-title">copy</span><span class="hljs-params">(SourceBean from, DstBean to)</span> <span class="hljs-keyword">throws</span> Exception</span>;
}

}

執行結果如下

結論

根據上面的運行結果，我們可以得出以下結論

property少，寫起來也不麻煩，就直接用傳統的getter/setter，性能最好
property多，轉換不頻繁，那就省點事吧，使用org.apache.commons.beanutils.BeanUtils.copyProperties
property多，轉換很頻繁，爲性能考慮，使用net.sf.cglib.beans.BeanCopier.BeanCopier，性能近乎getter/setter。但是BeanCopier的創建時消耗較大，所以不要頻繁創建該實體，最好的處理方式是靜態化或者緩存起來。

轉自:

Bean拷貝工具類性能比較