Spring中的@Pointcut切点详解

@Pointcut("execution(* com.aop.test.aspect..*.*(..))")
public void pointcut() {}

public interface Pointcut {
	ClassFilter getClassFilter();
	MethodMatcher getMethodMatcher();
}
// 类匹配
public interface ClassFilter {
	boolean matches(Class<?> clazz);
}
// 方法匹配
public interface MethodMatcher {
 	// 方法是否匹配切点（静态匹配）
	boolean matches(Method method, Class<?> targetClass);
 	// 代理对象已经创建，静态匹配成功（两个参数的matches）
    // 方法调用时检查三个参数的matches方法是否匹配
	boolean isRuntime();
 	// 动态匹配，方法调用时带参数判断
	boolean matches(Method method, Class<?> targetClass, Object... args);
}

public abstract class AbstractExpressionPointcut implements ExpressionPointcut, Serializable {
	@Nullable
	private String location;
	@Nullable
	private String expression;
}
public class AspectJExpressionPointcut extends AbstractExpressionPointcut
		implements ClassFilter, IntroductionAwareMethodMatcher, BeanFactoryAware {
	private static final Set<PointcutPrimitive> SUPPORTED_PRIMITIVES = new HashSet<>();
	static {
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.EXECUTION);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.ARGS);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.REFERENCE);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.THIS);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.TARGET);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.WITHIN);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.AT_ANNOTATION);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.AT_WITHIN);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.AT_ARGS);
		SUPPORTED_PRIMITIVES.add(PointcutPrimitive.AT_TARGET);
	}
	@Nullable
	private Class<?> pointcutDeclarationScope;
	private String[] pointcutParameterNames = new String[0];
	private Class<?>[] pointcutParameterTypes = new Class<?>[0];
	@Nullable
	private BeanFactory beanFactory;
	@Nullable
	private transient ClassLoader pointcutClassLoader;
	@Nullable
	private transient PointcutExpression pointcutExpression;
	private transient Map<Method, ShadowMatch> shadowMatchCache = new ConcurrentHashMap<>(32);
}

public abstract class StaticMethodMatcherPointcut extends StaticMethodMatcher implements Pointcut {
	// 定义类过滤字段
    private ClassFilter classFilter = ClassFilter.TRUE;
}
abstract class TransactionAttributeSourcePointcut extends StaticMethodMatcherPointcut implements Serializable {
	protected TransactionAttributeSourcePointcut() {
		setClassFilter(new TransactionAttributeSourceClassFilter());
	}
    // 方法是否匹配
	@Override
	public boolean matches(Method method, Class<?> targetClass) {
		TransactionAttributeSource tas = getTransactionAttributeSource();
		return (tas == null || tas.getTransactionAttribute(method, targetClass) != null);
	}
	// 获取事务属性，交给子类实现
	@Nullable
	protected abstract TransactionAttributeSource getTransactionAttributeSource();
	// 内部类实现的类过滤器
	private class TransactionAttributeSourceClassFilter implements ClassFilter {
		@Override
		public boolean matches(Class<?> clazz) {
            // 基础设施类忽略
			if (TransactionalProxy.class.isAssignableFrom(clazz) ||
					TransactionManager.class.isAssignableFrom(clazz) ||
					PersistenceExceptionTranslator.class.isAssignableFrom(clazz)) {
				return false;
			}
            // 调用子类实现的获取事务属性
			TransactionAttributeSource tas = getTransactionAttributeSource();
			return (tas == null || tas.isCandidateClass(clazz));
		}
	}
}

public class BeanFactoryTransactionAttributeSourceAdvisor extends AbstractBeanFactoryPointcutAdvisor {
    @Nullable
    private TransactionAttributeSource transactionAttributeSource;
    // 匿名内部类实现
    private final TransactionAttributeSourcePointcut pointcut = new TransactionAttributeSourcePointcut() {
        @Nullable
        protected TransactionAttributeSource getTransactionAttributeSource() {
            return BeanFactoryTransactionAttributeSourceAdvisor.this.transactionAttributeSource;
        }
    };
}