AspectJ

AspectJ is an open source programming language created in 2001.

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Try now: Riju

AspectJ is an aspect-oriented programming (AOP) extension created at PARC for the Java programming language. It is available in Eclipse Foundation open-source projects, both stand-alone and integrated into Eclipse. AspectJ has become a widely used de facto standard for AOP by emphasizing simplicity and usability for end users. Read more on Wikipedia...

AspectJ website
AspectJ Wikipedia page
There are at least 671 AspectJ repos on GitHub
AspectJ first developed in Eclipse Foundation
file extensions for AspectJ include aj
The Google BigQuery Public Dataset GitHub snapshot shows 734 users using AspectJ in 793 repos on GitHub
Explore AspectJ snippets on Rosetta Code
AspectJ on HOPL
AspectJ appears in the TIOBE Index
AspectJ Ubuntu package
ANTLR grammar for AspectJ
Pygments supports syntax highlighting for AspectJ
GitHub supports syntax highlighting for AspectJ
AspectJ appears in the Quine Relay project
See also: (4 related languages)Java, Eclipse, Emacs, ISBN

Example from Riju:

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello, world!");
    }
}

Example from hello-world:

System.out.println("Hello World");

Example from Linguist:

package com.blogspot.miguelinlas3.aspectj.cache;

import java.util.Map;
import java.util.WeakHashMap;

import org.aspectj.lang.JoinPoint;

import com.blogspot.miguelinlas3.aspectj.cache.marker.Cacheable;

/**
 * This simple aspect simulates the behaviour of a very simple cache
 *  
 * @author migue
 *
 */
public aspect CacheAspect {

	public pointcut cache(Cacheable cacheable): execution(@Cacheable * * (..)) && @annotation(cacheable);
	
	Object around(Cacheable cacheable): cache(cacheable){
	
		String evaluatedKey = this.evaluateKey(cacheable.scriptKey(), thisJoinPoint);
		
		if(cache.containsKey(evaluatedKey)){
			System.out.println("Cache hit for key " + evaluatedKey);
			return this.cache.get(evaluatedKey);
		}
		
		System.out.println("Cache miss for key " + evaluatedKey);
		Object value = proceed(cacheable);
		cache.put(evaluatedKey, value);
		return value;
	}
	
	protected String evaluateKey(String key, JoinPoint joinPoint) {
		// TODO add some smart staff to allow simple scripting in @Cacheable annotation
		return key;
	}
	
	protected Map<String, Object> cache = new WeakHashMap<String, Object>();
}

Example from Wikipedia:

pointcut set() : execution(* set*(..) ) && this(Point);

Feature	Supported	Token	Example
Binary Literals	✓		// 0[bB][01][01_]*[lL]?
Integers	✓		// 0\|[1-9][0-9_]*[lL]?
Floats	✓		// ([0-9][0-9_]\.([0-9][0-9_])?\|\.[0-9][0-9_])([eE][+\-]?[0-9][0-9_])?[fFdD]?\|[0-9][eE][+\-]?[0-9][0-9_][fFdD]?\|[0-9]([eE][+\-]?[0-9][0-9_])?[fFdD]\|0[xX]([0-9a-fA-F][0-9a-fA-F_]\.?\|([0-9a-fA-F][0-9a-fA-F_])?\.[0-9a-fA-F][0-9a-fA-F_])[pP][+\-]?[0-9][0-9_][fFdD]?
Hexadecimals	✓		// 0[xX][0-9a-fA-F][0-9a-fA-F_]*[lL]?
Octals	✓		// 0[0-7_]+[lL]?
Strings	✓	"	"Hello world"
MultiLine Comments	✓	/* */	/* A comment */
Print() Debugging	✓	System.out.println
Comments	✓		// A comment
Line Comments	✓	//	// A comment
Semantic Indentation	X

AspectJ - Programming language

Language features