org.aspectj/docs/release/README-1.7.0.adoc

= AspectJ 1.7.0

_© Copyright 2011 Contributors. All rights reserved._

The full list of resolved issues in 1.7.0 is available
https://bugs.eclipse.org/bugs/buglist.cgi?query_format=advanced;bug_status=RESOLVED;bug_status=VERIFIED;bug_status=CLOSED;product=AspectJ;target_milestone=1.7.0;[here]

_Release info:_

* _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 https://bugs.eclipse.org/bugs/show_bug.cgi?id=367673[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:

[source, text]
....
-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:

[source, java]
....
aspect Foo {
  before(): execution(* *(..)) {
    List ls = new ArrayList<>();
  }
}
....

- Diamond operator in ITD:

[source, java]
....
public List DiamondITD.ls = new ArrayList<>();
....

- Underscore literals and binary literals in advice:

[source, java]
....
before(): execution(* *(..)) {
  int onemill = 1_000_000;
  int four =0b100;
}
....

- Multi-catch:``

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

- String switch:``

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

- Try with resources:``

[source, java]
....
try (
  InputStream in = new FileInputStream(src);
  OutputStream out = new FileOutputStream(dest))
{
  // code
}
....