© Copyright 2011 Contributors. All rights reserved.

# AspectJ 1.7.0 Readme

The full list of resolved issues in 1.7.0 is available here.

- 1.7.0 available 2-Jul-2012
- 1.7.0.RC1 available 25-May-2012
- 1.7.0.M1 available 16-Dec-2011

## Notable Changes

### Java 7 bytecode weaving

The first milestone of 1.7.0 upgraded the compiler but this still left the weaver with some issues if it had to weave into bytecode containing some of the new features that were allowed by Java 1.7. In particular this meant any bytecode containing the INVOKEDYNAMIC (new instruction for 1.7) and the related new constant pool entry types that support it. RC1 now supports weaving into bytecode containing these features. However, the new INVOKEDYNAMIC instruction does not surface as a join point yet so you cannot write a pointcut to match on it. If you use execution() pointcuts as opposed to call() then you will still be able to advise what the invokedynamic actually calls.

### Bytecode caching for loadtime weaving

Under bug 367673 we have had a contribution (thanks John Kew!) that enables a bytecode cache for loadtime weaving. The details and some rudimentary benchmark numbers are in the bug. Basically it caches woven bytecode on first start of a system using LTW and then reuses that woven bytecode on subsequent starts - this saves weaving time and also memory consumption. To activate it, use the following system properties:

    -Daj.weaving.cache.enabled=true
    -Daj.weaving.cache.dir=/tmp/aspectj-cache/

### Upgrade to Java 7

For AspectJ 1.7.0, AspectJ moved from Eclipse JDT Core 0.785_R33x (Eclipse 3.3) to Eclipse JDT Core 0.B79_R37x (Eclipse 3.7). This is a big change where AspectJ is picking up four years of change from the Eclipse compiler.

It means that you can now use the new Java 7 language constructs in your programs:

- Diamond operator in advice: ``

    aspect Foo {
      before(): execution(* *(..)) {
        List<String> ls = new ArrayList<>();
      }
    }

- Diamond operator in ITD: ``

    public List<String> DiamondITD.ls = new ArrayList<>();

- Underscore literals and binary literals in advice: ``

      before(): execution(* *(..)) {
        int onemill = 1_000_000;
        int four =0b100;
      }

- Multi-catch:``

    before(): execution(* main(..)) {
        try {
          foo("abc");
        } catch (ExceptionA | ExceptionB ex) {
          bar(ex);
        }
    }

- String switch:``

     before(String s): execution(* *(..)) && args(s) {
       switch(s) {
         case "quux":
           foo();
           break;
         case "bar":
           foo();
           break;
         default:
           foo();
           break;
       }
     }

- Try with resources:``

       try (
         InputStream in = new FileInputStream(src);
         OutputStream out = new FileOutputStream(dest))
       {
         // code
       }

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