public Object invoke(MethodInvocation methodInvocation) throws Throwable {
assertAuthorized(methodInvocation);
return methodInvocation.proceed();
}
public void assertAuthorized(MethodInvocation mi) throws AuthorizationException {
try {
((AuthorizingAnnotationHandler)getHandler()).assertAuthorized(getAnnotation(mi));
}
catch(AuthorizationException ae) {
if (ae.getCause() == null) ae.initCause(new AuthorizationException("Not authorized to invoke method: " + mi.getMethod()));
throw ae;
}
}
}
现在分析其中一种实现类PermissionAnnotationMethodInterceptor，也是用的最多的，但是这个类的实际代码很少，很明显上述分析的getHandler在PermissionAnnotationMethodInterceptor中返回值为PermissionAnnotationHandler。
public class PermissionAnnotationMethodInterceptor extends AuthorizingAnnotationMethodInterceptor {
public PermissionAnnotationMethodInterceptor() {
super( new PermissionAnnotationHandler() );
}
public PermissionAnnotationMethodInterceptor(AnnotationResolver resolver) {
super( new PermissionAnnotationHandler(), resolver);
}
}
在PermissionAnnotationHandler类中，终于发现实际的检验逻辑，还是调用的Subject.checkPermission()进行校验。
public class PermissionAnnotationHandler extends AuthorizingAnnotationHandler {
public PermissionAnnotationHandler() {
super(RequiresPermissions.class);
}
protected String[] getAnnotationValue(Annotation a) {
RequiresPermissions rpAnnotation = (RequiresPermissions) a;
return rpAnnotation.value();
}
public void assertAuthorized(Annotation a) throws AuthorizationException {
if (!(a instanceof RequiresPermissions)) return;
RequiresPermissions rpAnnotation = (RequiresPermissions) a;
String[] perms = getAnnotationValue(a);
Subject subject = getSubject();
if (perms.length == 1) {
subject.checkPermission(perms[0]);
return;
}
if (Logical.AND.equals(rpAnnotation.logical())) {
getSubject().checkPermissions(perms);
return;
}
if (Logical.OR.equals(rpAnnotation.logical())) {
boolean hasAtLeastOnePermission = false;
for (String permission : perms) if (getSubject().isPermitted(permission)) hasAtLeastOnePermission = true;
if (!hasAtLeastOnePermission) getSubject().checkPermission(perms[0]);
}
}
}
3|0实现类似编程式AOP
定义一个注解
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface Log {
String value() default "";
}
继承StaticMethodMatcherPointcutAdvisor类，并实现相关的方法。
@SuppressWarnings("serial")
@Component
public class HelloAdvisor extends StaticMethodMatcherPointcutAdvisor{
public HelloAdvisor() {
setAdvice(new LogMethodInterceptor());
}
public boolean matches(Method method, Class targetClass) {
Method m = method;
if ( isAuthzAnnotationPresent(m) ) {
return true;
}
if ( targetClass != null) {
try {
m = targetClass.getMethod(m.getName(), m.getParameterTypes());
return isAuthzAnnotationPresent(m);
} catch (NoSuchMethodException ignored) {
}
}
return false;
}