目錄

• 文件目錄
• 切點表達式
• 源碼
• 測試
• 測試效果

文件目錄

soundsystem
|- ConcertConfig
|- CompackDisc
|- TrackCounter

切點表達式

返回任意類型    方法所屬的類型         方法     接受int類型的參數(shù)
         |-||---------------------| |-------||---|
execution(* soundsystem.CompactDisc.playTrack(int)) && args(trackNumber)
                                                       |---------------|
                                                            指定參數(shù)                                                       

源碼

ConcertConfig.java

@Configuration
@EnableAspectJAutoProxy
@ComponentScan
public class ConcertConfig {
}

CompactDisc.java

@Component
public class CompactDisc {
    public void playTrack(int n) {
        System.out.println("playTrack(" + n + ")");
    }
}

TrackCounter.java

@Aspect
@Component
public class TrackCounter {
    private Map<Integer, Integer> trackCounts = new HashMap<>();

    @Pointcut("execution(* soundsystem.CompactDisc.playTrack(int)) && args(trackNumber)")
    public void trackPlayed(int trackNumber){
    }

    @Before("trackPlayed(trackNumber)")
    public void countTrack(int trackNumber) {
        int currentCount = getPlayCount(trackNumber);
        trackCounts.put(trackNumber, currentCount + 1);

        for(Integer key : trackCounts.keySet())
            System.out.println(key + ":" + trackCounts.get(key));
    }

    public int getPlayCount(int trackNumber) {
        return trackCounts.containsKey(trackNumber) ? trackCounts.get(trackNumber) : 0;
    }
}

測試

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {ConcertConfig.class})
@FixMethodOrder(MethodSorters.NAME_ASCENDING)
public class CompactDiscTest { 

    @Autowired
    private CompactDisc cd;

    @Test
    public void testPlayTrack() throws Exception {
        cd.playTrack(20);
        cd.playTrack(30);
        cd.playTrack(60);
    }
} 

測試效果

20:1
playTrack(20)
20:1
30:1
playTrack(30)
20:1
60:1
30:1
playTrack(60)

Process finished with exit code 0