詳解spring切面使用傳遞給被通知方法的參數(shù)
本文介紹了詳解spring切面使用傳遞給被通知方法的參數(shù),分享給大家,具體如下:
場景:
BlankDisc代表CD實體,可以通過playTrack()方法直接播放某一個磁道中的歌曲。
需求是記錄每個磁道被播放的次數(shù)。
一種方法就是修改playTrack()方法,直接在每次調(diào)用的時候記錄這個數(shù)量。但是,記錄磁道的播放次數(shù)與播放本身是不同的關注點,因此不應該屬于playTrack()方法。這應該是切面要完成的任務。
CompactDisc接口
public interface CompactDisc {
//播放某一個磁道中的歌曲
void playTrack(String track);
}
實現(xiàn)類BlankDisc
public class BlankDisc implements CompactDisc {
private String title;
private String artist;
private List<String> tracks;
public void setTitle(String title) {
this.title = title;
}
public void setArtist(String artist) {
this.artist = artist;
}
public void setTracks(List<String> tracks) {
this.tracks = tracks;
}
@Override
public void playTrack(String track) {
System.out.println("-Track: " + track);
}
}
切面類TraceCount
/**
* 切面類的任務:記錄每個磁道被播放的次數(shù)
* Created by Administrator on 2017/12/1.
*/
@Component
@Aspect
public class TrackCounter {
private Map<String, Integer> trackCounts = new HashMap<>();
@Pointcut("execution(* chapter04.aop_args.BlankDisc.playTrack(String)) && args(track)")
public void trackPlayed(String track) {
}
//在播放前,為該磁道計數(shù)
@Before("trackPlayed(track)")
public void countTrack(String track) {
int currentCount = getPlayCount(track);
trackCounts.put(track, currentCount + 1);
}
public int getPlayCount(String track) {
return trackCounts.containsKey(track) ? trackCounts.get(track) : 0;
}
}
applicationContext.xml配置文件
<context:component-scan base-package="aop_test,chapter04"/>
<bean id="compactDisc"
class="chapter04.aop_args.BlankDisc">
<property name="title" value="Sgt. Pepper's Lonely Hearts Club Band" />
<property name="artist" value="The Beatles" />
<property name="tracks">
<list>
<value>Sgt. Pepper's Lonely Hearts Club Band</value>
<value>With a Little Help from My Friends</value>
<value>Lucy in the Sky with Diamonds</value>
<value>Getting Better</value>
<value>Fixing a Hole</value>
<value>She's Leaving Home</value>
<value>Being for the Benefit of Mr. Kite!</value>
<value>Within You Without You</value>
<value>When I'm Sixty-Four</value>
<value>Lovely Rita</value>
<value>Good Morning Good Morning</value>
<value>Sgt. Pepper's Lonely Hearts Club Band (Reprise)</value>
<value>A Day in the Life</value>
</list>
</property>
</bean>
<!-- 開啟aop注解 -->
<aop:aspectj-autoproxy/>
測試
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class test_aop_args {
@Autowired
CompactDisc cd;
@Autowired
TrackCounter trackCounter;
@Test
public void test(){
cd.playTrack("Sgt. Pepper's Lonely Hearts Club Band");
cd.playTrack("With a Little Help from My Friends");
cd.playTrack("Lucy in the Sky with Diamonds");
cd.playTrack("Sgt. Pepper's Lonely Hearts Club Band");
cd.playTrack("With a Little Help from My Friends");
cd.playTrack("Sgt. Pepper's Lonely Hearts Club Band");
System.out.println(trackCounter.getPlayCount("Sgt. Pepper's Lonely Hearts Club Band"));
System.out.println(trackCounter.getPlayCount("With a Little Help from My Friends"));
System.out.println(trackCounter.getPlayCount("Lucy in the Sky with Diamonds"));
System.out.println(trackCounter.getPlayCount("Getting Better"));
}
}
測試結(jié)果 3,2,1,0
以上就是本文的全部內(nèi)容,希望對大家的學習有所幫助,也希望大家多多支持腳本之家。
相關文章
java.net.SocketException: Connection reset 解決方法
最近糾結(jié)致死的一個java報錯java.net.SocketException: Connection reset 終于得到解決2013-03-03
Java中通過sftp協(xié)議實現(xiàn)上傳下載的示例代碼
在java開發(fā)中遇到需要將linux系統(tǒng)中指定目錄下的文件下載到windows本地的需求,本文就來介紹Java中通過sftp協(xié)議實現(xiàn)上傳下載,具有一定的參考價值,感興趣的可以了解一下2024-06-06

