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- © Copyright 2014 Contributors.
- All rights reserved.
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-
- <h1>AspectJ 1.8.2 Readme</h1>
-
- <p>The full list of resolved issues in 1.8.2 is available
- <a href="https://bugs.eclipse.org/bugs/buglist.cgi?query_format=advanced;bug_status=RESOLVED;bug_status=VERIFIED;bug_status=CLOSED;product=AspectJ;target_milestone=1.8.2;">here</a></h2>.</p>
-
- <ul>
- <li>1.8.2 available 14-Aug-2014
- </ul>
-
- <h2>Notable changes</h2>
-
- <p>Although only a few bugs have been fixed here, they are quite important ones:</p>
-
- <h3>Update to more recent Eclipse Compiler</h3>
-
- <p>AspectJ is now based on a more up to date Eclipse compiler level (git hash 2b07958) so includes all the latest fixes</p>
-
- <h3>Correct handling of RuntimeInvisibleTypeAnnotations (type annotations without runtime visibility)</h3>
-
- <p>For anyone weaving code containing these kind of type annotations, this is an important fix. Although AspectJ does not currently
- support pointcuts matching on these kinds of annotation it was crashing when they were encountered. That is now fixed.</p>
-
- <h3>Annotation processing</h3>
-
- <p>A very long standing issue, the AspectJ compiler now supports annotation processors thanks to some work by Sergey Stupin.</p>
-
- <p>Here is a short example, a very basic annotation and application:</p>
-
- <h4>Marker.java</h4>
- <code><pre>
- import java.lang.annotation.Retention;
- import java.lang.annotation.RetentionPolicy;
-
- @Retention(RetentionPolicy.RUNTIME)
- public @interface Marker { }
- </pre></code>
-
- <h4>Code.java</h4>
- <code><pre>
- public class Code {
-
- public static void main(String []argv) {
- new Code().moo();
- new Code().boo();
- new Code().too();
- new Code().woo();
- }
-
- public void moo() {}
-
- @Marker
- public void boo() {}
-
- @Marker
- public void too() {}
-
- public void woo() {}
- }
- </pre></code>
-
- <p>And now a basic annotation processor. This processor will find methods in the source marked with the annotation <tt>Marker</tt> and for
- each one generate an aspect tailored to advising that method (this *is* a contrived demo!)</p>
-
- <h4>DemoProcessor.java</h4>
- <code><pre>
- import java.io.*;
- import javax.tools.*;
- import java.util.*;
- import javax.annotation.processing.*;
- import javax.lang.model.*;
- import javax.lang.model.element.*;
-
- @SupportedAnnotationTypes(value= {"*"})
- @SupportedSourceVersion(SourceVersion.RELEASE_6)
- public class DemoProcessor extends AbstractProcessor {
-
- private Filer filer;
-
- @Override
- public void init(ProcessingEnvironment env) {
- filer = env.getFiler();
- }
-
- @Override
- public boolean process(Set elements, RoundEnvironment env) {
- // Discover anything marked with @Marker
- for (Element element: env.getElementsAnnotatedWith(Marker.class)) {
- if (element.getKind() == ElementKind.METHOD) {
- // For any methods we find, create an aspect:
- String methodName = element.getSimpleName().toString();
- String aspectText =
- "public aspect Advise_"+methodName+" {\n"+
- " before(): execution(* "+methodName+"(..)) {\n"+
- " System.out.println(\""+methodName+" running\");\n"+
- " }\n"+
- "}\n";
- try {
- JavaFileObject file = filer.createSourceFile("Advise_"+methodName, element);
- file.openWriter().append(aspectText).close();
- System.out.println("Generated aspect to advise "+element.getSimpleName());
- } catch (IOException ioe) {
- // already creates message can appear if processor runs more than once
- if (!ioe.getMessage().contains("already created")) {
- ioe.printStackTrace();
- }
- }
- }
- }
- return true;
- }
- }
- </pre></code>
-
- <p>With those sources, we compile the processor:</p>
- <code><pre>ajc -1.6 DemoProcessor.java Marker.java</pre></code>
-
- <p>Now compile the code with the processor specified:</p>
- <code><pre>ajc -1.6 -processor DemoProcessor -showWeaveInfo Code.java Marker.java</pre></code>
- <code><pre>
- Generated aspect to advise too
- Generated aspect to advise boo
- Join point 'method-execution(void Code.boo())' in Type 'Code' (Code.java:14) advised by before advice from 'Advise_boo' (Advise_boo.java:2)
- Join point 'method-execution(void Code.too())' in Type 'Code' (Code.java:17) advised by before advice from 'Advise_too' (Advise_too.java:2)
- </pre></code>
-
- <p>Notice the processor generates the aspects and then they are woven into the code being compiled immediately.</p>
-
- <p>Finally we can run it:</p>
- <code><pre>java Code
- boo running
- too running
- </pre></code>
-
- <p><b>Note:</b> There is still work to be done to get annotation processors behaving under AJDT.
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