JarCastinggiftwrap
A Dagger 2 inspired wrapper generator library
giftwrap generates decorator classes at compile-time
Usage
Create the annotation
@Retention(RetentionPolicy.SOURCE)
@Target(ElementType.METHOD)
@InterceptedBy(LoggerInterceptor.class)
public @interface Logged {
LogLevel value() default LogLevel.DEBUG;
}
Create the corresponding interceptor
public class LoggerInterceptor implements Interceptor<Logged> {
private static final Logger logger = Logger.getLogger("entrylogger");
@Override
public Object intercept(Interception<Logged> interception) throws Exception {
Level level = interception.getAnnotation().value().julLevel();
logger.log(level, "Entering method " + interception.getMethodName());
return interception.proceed();
}
}
Annotate your class
@GiftWrap
public class Whatever {
@Logged(LogLevel.DEBUG)
@Transactional
public String doWhatever(String result) throws IOException {
return result;
}
}
Instantiate the wrapper
Whatever object = new WhateverIntercepted(
contructor, arguments, ofWhatever,
new LoggerInterceptor(),
new TransactionInterceptor());
Have a look at the stack
c.g.a.g.example.Whatever.doWhatever(Whatever.java:20)
c.g.a.g.example.WhateverIntercepted.access$0(WhateverIntercepted.java:1)
c.g.a.g.example.WhateverIntercepted$1.call(WhateverIntercepted.java:21)
c.g.a.g.Interception.proceed(Interception.java:32)
c.g.a.g.example.LoggerInterceptor.intercept(LoggerInterceptor.java:18)
c.g.a.g.InterceptorCallable.call(InterceptorCallable.java:27)
c.g.a.g.Interception.proceed(Interception.java:32)
c.g.a.g.example.TransactionInterceptor.intercept(TransactionInterceptor.java:10)
c.g.a.g.InterceptorCallable.call(InterceptorCallable.java:27)
c.g.a.g.example.WhateverIntercepted.doWhatever(WhateverIntercepted.java:35)