1. 程式人生 > >Spring實踐:面向切面程式設計(AOP)

Spring實踐:面向切面程式設計(AOP)

原文連結:http://blog.csdn.net/zjf280441589/article/details/50816802


AOP引介


AOP(Aspect Oriented Programing)面向切面程式設計採用橫向抽取機制,以取代傳統的縱向繼承體系的重複性程式碼(如效能監控/事務管理/安全檢查/快取實現等).

橫向抽取程式碼複用: 基於代理技術,在不修改原來程式碼的前提下,對原有方法進行增強.


Spring AOP 歷史


1.2開始, Spring開始支援AOP技術(Spring AOP).Spring AOP使用純Java實現,不需要專門的編譯過程和類載入器,在執行期通過代理方式向目標類織入增強程式碼.

2.0之後, 為了簡化AOP開發, Spring開始支援AspectJ(一個基於Java的AOP框架)框架.


AOP相關術語


術語 中文 描述
Joinpoint 連線點 指那些被攔截到的點.在Spring中,這些點指方法(因為Spring只支援方法型別的連線點).
Pointcut 切入點 指需要(配置)被增強的Joinpoint.
Advice
通知/增強 指攔截到Joinpoint後要做的操作.通知分為前置通知/後置通知/異常通知/最終通知/環繞通知等.
Aspect 切面 切入點和通知的結合.
Target 目標物件 需要被代理(增強)的物件.
Proxy 代理物件 目標物件被AOP 織入 增強/通知後,產生的物件.
Weaving 織入 指把增強/通知應用到目標物件來建立代理物件
過程(Spring採用動態代理織入,AspectJ採用編譯期織入和類裝載期織入).
Introduction 引介 一種特殊通知,在不修改類程式碼的前提下,可以在執行期為類動態地新增一些Method/Field(不常用).

其他關於AOP理論知識可參考AOP技術研究.


AOP實現


Spring AOP代理實現有兩種:JDK動態代理和Cglib框架動態代理, JDK動態代理可以參考部落格代理模式的動態代理部分, 在這裡僅介紹CGLib框架實現.


cglib 動態代理


cglib(Code Generation Library)是一個開源/高效能/高質量的Code生成類庫,可以在執行期動態擴充套件Java類與實現Java介面.

cglib比java.lang.reflect.Proxy更強的在於它不僅可以接管介面類的方法,還可以接管普通類的方法(cglib專案).從3.2開始, spring-core包中內建cglib類,因此可以不用新增額外依賴.


  • UserDAO(並沒有實現介面)

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-javadoc" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">/**
 *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @author</span> jifang
 *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @since</span> 16/3/3 上午11:16.
 */</span>
<span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="margin: 0px; padding: 0px; box-sizing: border-box;"><span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(102, 0, 102);">UserDAO</span> {</span>

    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box;">add</span>(Object o) {
        System.out.println(<span class="hljs-string" style="margin: 0px; padding: 0px; color: rgb(0, 136, 0); box-sizing: border-box;">"UserDAO -> Add: "</span> + o.toString());
    }

    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box;">get</span>(Object o) {
        System.out.println(<span class="hljs-string" style="margin: 0px; padding: 0px; color: rgb(0, 136, 0); box-sizing: border-box;">"UserDAO -> Get: "</span> + o.toString());
    }
}</code><ul class="pre-numbering" style="margin: 0px; padding: 6px 0px 40px; box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">1</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">2</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">3</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">4</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">5</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">6</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">7</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">8</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">9</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">10</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">11</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">12</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">13</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">14</li></ul>


  • CGLibProxyFactory

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="margin: 0px; padding: 0px; box-sizing: border-box;"><span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(102, 0, 102);">CGLibProxyFactory</span> {</span>

    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">private</span> Object target;

    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box;">CGLibProxyFactory</span>(Object target) {
        <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.target = target;
    }


    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">private</span> Callback callback = <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">new</span> MethodInterceptor() {

        <span class="hljs-javadoc" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">/**
         *
         *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> obj   代理物件
         *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> method    當期呼叫方法
         *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> args  方法引數
         *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> proxy 被呼叫方法的代理物件(用於執行父類的方法)
         *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @return</span>
         *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @throws</span> Throwable
         */</span>
        <span class="hljs-annotation" style="margin: 0px; padding: 0px; color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
        <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Object <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box;">intercept</span>(Object obj, Method method, Object[] args, MethodProxy proxy) <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">throws</span> Throwable {

            <span class="hljs-comment" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">// 前置增強</span>
            System.out.println(<span class="hljs-string" style="margin: 0px; padding: 0px; color: rgb(0, 136, 0); box-sizing: border-box;">"+ Before Advice ..."</span>);

            <span class="hljs-comment" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">// 執行目標方法</span>
            <span class="hljs-comment" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">//Object result = method.invoke(target, args);</span>
            Object result = proxy.invoke(target, args);

            <span class="hljs-comment" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">// 後置增強</span>
            System.out.println(<span class="hljs-string" style="margin: 0px; padding: 0px; color: rgb(0, 136, 0); box-sizing: border-box;">"+ After Advice ..."</span>);

            <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">return</span> result;
        }
    };

    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Object <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box;">createProxy</span>() {

        <span class="hljs-comment" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">// 1. 建立Enhancer物件</span>
        Enhancer enhancer = <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Enhancer();

        <span class="hljs-comment" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">// 2. cglib建立代理, 對目標物件建立子物件</span>
        enhancer.setSuperclass(target.getClass());

        <span class="hljs-comment" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">// 3. 傳入回撥介面, 對目標增強</span>
        enhancer.setCallback(callback);

        <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">return</span> enhancer.create();
    }

    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box;">main</span>(String[] args) {
        UserDAO proxy = (UserDAO) <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">new</span> CGLibProxyFactory(<span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">new</span> UserDAO()).createProxy();
        proxy.get(<span class="hljs-string" style="margin: 0px; padding: 0px; color: rgb(0, 136, 0); box-sizing: border-box;">"hello"</span>);
        proxy.add(<span class="hljs-string" style="margin: 0px; padding: 0px; color: rgb(0, 136, 0); box-sizing: border-box;">"world"</span>);
    }
}</code><ul class="pre-numbering" style="margin: 0px; padding: 6px 0px 40px; box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">1</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">2</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">3</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">4</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">5</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">6</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">7</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">8</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">9</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">10</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">11</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">12</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">13</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">14</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">15</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">16</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">17</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">18</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">19</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">20</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">21</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">22</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">23</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">24</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">25</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">26</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">27</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">28</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">29</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">30</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">31</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">32</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">33</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">34</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">35</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">36</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">37</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">38</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">39</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">40</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">41</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">42</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">43</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">44</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">45</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">46</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">47</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">48</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">49</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">50</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">51</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">52</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">53</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">54</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">55</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">56</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">57</li></ul>


AOP小結


Spring AOP的底層通過JDK/cglib動態代理為目標物件進行橫向織入:

1) 若目標物件實現了介面,則Spring使用JDK的java.lang.reflect.Proxy代理.

2) 若目標物件沒有實現介面,則Spring使用cglib庫生成目標物件的子類.

Spring只支援方法連線點,不提供屬性連線.

標記為final的方法不能被代理,因為無法進行覆蓋.

程式應優先對針對介面代理,這樣便於程式解耦/維護.


Spring AOP


AOP聯盟為通知Advice定義了org.aopalliance.aop.Advice介面, Spring在Advice的基礎上,根據通知在目標方法的連線點位置,擴充為以下五類:


通知 介面 描述
前置通知 MethodBeforeAdvice 在目標方法執行實施增強
後置通知 AfterReturningAdvice …執行實施增強
環繞通知 MethodInterceptor ..執行前後實施增強
異常丟擲通知 ThrowsAdvice …丟擲異常後實施增強
引介通知 IntroductionInterceptor 在目標類中新增新的方法和屬性(少用)


  • 新增Spring的AOP依賴

使用Spring的AOP和AspectJ需要在pom.xml中新增如下依賴:

<code class="hljs xml has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">dependency</span>></span>
    <span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">groupId</span>></span>org.springframework<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">groupId</span>></span>
    <span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">artifactId</span>></span>spring-aop<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">artifactId</span>></span>
    <span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">version</span>></span>${spring.version}<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">version</span>></span>
<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">dependency</span>></span>
<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">dependency</span>></span>
    <span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">groupId</span>></span>org.springframework<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">groupId</span>></span>
    <span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">artifactId</span>></span>spring-aspects<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">artifactId</span>></span>
    <span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">version</span>></span>${spring.version}<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">version</span>></span>
<span class="hljs-tag" style="margin: 0px; padding: 0px; color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(0, 0, 136);">dependency</span>></span></code><ul class="pre-numbering" style="margin: 0px; padding: 6px 0px 40px; box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">1</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">2</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">3</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">4</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">5</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">6</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">7</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">8</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">9</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">10</li><li></li></ul>


  • 定義Target

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-javadoc" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">/**
 *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @author</span> jifang
 *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @since</span> 16/3/3 下午2:50.
 */</span>
<span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="margin: 0px; padding: 0px; box-sizing: border-box;"><span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">interface</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(102, 0, 102);">OrderService</span> {</span>

    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">void</span> save();

    Integer delete(Integer param);
}</code><ul class="pre-numbering" style="margin: 0px; padding: 6px 0px 40px; box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">1</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">2</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">3</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">4</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">5</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">6</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">7</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">8</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">9</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">10</li></ul>
<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="margin: 0px; padding: 0px; box-sizing: border-box;"><span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(102, 0, 102);">OrderServiceImpl</span> <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">implements</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(102, 0, 102);">OrderService</span> {</span>

    <span class="hljs-annotation" style="margin: 0px; padding: 0px; color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box;">save</span>() {
        System.out.println(<span class="hljs-string" style="margin: 0px; padding: 0px; color: rgb(0, 136, 0); box-sizing: border-box;">"新增..."</span>);
    }

    <span class="hljs-annotation" style="margin: 0px; padding: 0px; color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
    <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> Integer <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box;">delete</span>(Integer param) {
        System.out.println(<span class="hljs-string" style="margin: 0px; padding: 0px; color: rgb(0, 136, 0); box-sizing: border-box;">"刪除..."</span>);
        <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">return</span> param;
    }
}</code><ul class="pre-numbering" style="margin: 0px; padding: 6px 0px 40px; box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">1</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">2</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">3</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">4</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">5</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">6</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">7</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">8</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">9</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">10</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">11</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">12</li><li style="margin: 0px; padding: 0px 5px; box-sizing: border-box;">13</li><li></li></ul>


  • 定義Advice

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-javadoc" style="margin: 0px; padding: 0px; color: rgb(136, 0, 0); box-sizing: border-box;">/**
 * 實現MethodInterceptor介面定義環繞通知
 *
 *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @author</span> jifang
 *<span class="hljs-javadoctag" style="margin: 0px; padding: 0px; color: rgb(102, 0, 102); box-sizing: border-box;"> @since</span> 16/3/6 下午2:54.
 */</span>
<span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="margin: 0px; padding: 0px; box-sizing: border-box;"><span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="margin: 0px; padding: 0px; box-sizing: border-box; color: rgb(102, 0, 102);">ConcreteInterceptor</span> <span class="hljs-keyword" style="margin: 0px; padding: 0px; color: rgb(0, 0, 136); box-sizing: border-box;">