目录

• 文件目录
• 切点表达式
• 源码
• 测试
• 测试效果

文件目录

soundsystem
|- ConcertConfig
|- CompackDisc
|- TrackCounter

切点表达式

返回任意类型    方法所属的类型         方法     接受int类型的参数
         |-||---------------------| |-------||---|
execution(* soundsystem.CompactDisc.playTrack(int)) && args(trackNumber)
                                                       |---------------|
                                                            指定参数                                                       

源码

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;
    }
}

测试

@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);
    }
} 

测试效果

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

Process finished with exit code 0