README.md

giftwrap

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)