Recipe9.2.Capturing All Join Points Within a Particular Package

Recipe 9.2. Capturing All Join Points Within a Particular Package

Problem

You want to capture all the join points within classes that are, in turn, within a particular package scope.

Solution

Use the within(TypePattern) pointcut using the TypePattern to specify a package.

Discussion

The within(TypePattern) pointcut provides a useful means of specifying an interest in the join points that occur in every class within a package by using wildcards. Entire packages of join points can be included or excluded from the rest of the pointcut logic using the appropriate wildcards in the TypePattern.

Example 9-2 shows the within(TypePattern) pointcut being used to capture all the join points within the packageA package.

Example 9-2. Using the within(TypePattern) pointcut to capture join points within a specific package

public aspect WithinPackageRecipe  {    /*        Specifies calling advice on any join point is encountered within         the defined scope:            Scope: packageA    */    pointcut withinPackageA( ) : within(packageA.*);    // Advice declaration    before( ) : withinPackageA( ) && !within(WithinPackageRecipe +)    {       System.out.println("-------------- Aspect Advice Logic ---------------");       System.out.println("In the advice picked by " + "withinPackageA( )");       System.out.println("Join Point Kind: " + thisJoinPoint.getKind( ));       System.out.println("Signature: " +            thisJoinPoint.getStaticPart( ).getSignature( ));       System.out.println(          "Source Line: " + thisJoinPoint.getStaticPart( ).getSourceLocation( ));       System.out.println("--------------------------------------------------");    } }

The within(TypePattern) pointcut's key characteristics are listed in Recipe Recipe 6.1.

See Also

Recipe 5.1 shows some of the wildcard variations that can be used in a TypePattern; Recipe 9.1 shows the more traditional use of the within(TypePattern) pointcut definition for capturing the join points within a specific class; the mechanisms by which pointcuts can be combined are described in the recipes in Chapter 12; the within(TypePattern) pointcut is often negated to remove an aspect from the scope of the weaving using the unary NOT (!) operator as described in Recipe 12.4.