circuitbreaker/invocations/AnnotatedInvocation.java

package dk.thoerup.circuitbreaker.invocations;

/* a annotation based invocation if it infeasible or you just don't like to implement yet another interface 
 * 
 *      class MyInvocation {
 *              @CircuitBreakerMethod
 *              public void doSomething() {}
 *      }
 *      
 *      ..... snip......
 *
 *      MyInvocation my = new MyInvocation(); 
 *      AnnotatedInvocation invok = new AnnotatedInvocation(my);
 *  Object out = CircuitBreakerManager.getManager().getCircuitBreaker("mycb").invoke(invok);
 * 
 */


import java.lang.annotation.Annotation;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import dk.thoerup.circuitbreaker.CircuitInvocation;

public class AnnotatedInvocation<T> implements CircuitInvocation<T> {
        
        public static class CBAnnotationException extends Exception {
                public CBAnnotationException() {
                        super("No method found annotated with @CircuitBreakerMethod");
                }
                private static final long serialVersionUID = 1L;
                
        }
        
        private Object obj;
        
        public AnnotatedInvocation(Object obj) {
                this.obj = obj;
        }

        @SuppressWarnings("unchecked")
        public T proceed() throws Exception {
                
                Method methods[] = obj.getClass().getMethods();
                for(Method current : methods) {
                        Annotation anno = current.getAnnotation(CircuitBreakerMethod.class);

                        
                        if (anno != null ) {
                                try {
                                        return (T) current.invoke(obj, (Object[])null); //invoke the first method annotated
                                } catch (InvocationTargetException e) {
                                        throw (Exception) e.getCause(); //unwrap any exception from InvocationTargetException
                                }
                        }
                        
                }
                
                throw new CBAnnotationException(); //if no method was found
        }
}
1	package dk.thoerup.circuitbreaker.invocations;
2
3	/* a annotation based invocation if it infeasible or you just don't like to implement yet another interface
4	*
5	* class MyInvocation {
6	* @CircuitBreakerMethod
7	* public void doSomething() {}
8	* }
9	*
10	* ..... snip......
11	*
12	* MyInvocation my = new MyInvocation();
13	* AnnotatedInvocation invok = new AnnotatedInvocation(my);
14	* Object out = CircuitBreakerManager.getManager().getCircuitBreaker("mycb").invoke(invok);
15	*
16	*/
17
18
19	import java.lang.annotation.Annotation;
20	import java.lang.reflect.InvocationTargetException;
21	import java.lang.reflect.Method;
22
23	import dk.thoerup.circuitbreaker.CircuitInvocation;
24
25	public class AnnotatedInvocation<T> implements CircuitInvocation<T> {
26
27	public static class CBAnnotationException extends Exception {
28	public CBAnnotationException() {
29	super("No method found annotated with @CircuitBreakerMethod");
30	}
31	private static final long serialVersionUID = 1L;
32
33	}
34
35	private Object obj;
36
37	public AnnotatedInvocation(Object obj) {
38	this.obj = obj;
39	}
40
41	@SuppressWarnings("unchecked")
42	public T proceed() throws Exception {
43
44	Method methods[] = obj.getClass().getMethods();
45	for(Method current : methods) {
46	Annotation anno = current.getAnnotation(CircuitBreakerMethod.class);
47
48
49	if (anno != null ) {
50	try {
51	return (T) current.invoke(obj, (Object[])null); //invoke the first method annotated
52	} catch (InvocationTargetException e) {
53	throw (Exception) e.getCause(); //unwrap any exception from InvocationTargetException
54	}
55	}
56
57	}
58
59	throw new CBAnnotationException(); //if no method was found
60	}
61	}