diff options
Diffstat (limited to 'docs/pdGuideDB/ltwdump.adoc')
| -rw-r--r-- | docs/pdGuideDB/ltwdump.adoc | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/docs/pdGuideDB/ltwdump.adoc b/docs/pdGuideDB/ltwdump.adoc new file mode 100644 index 000000000..3f97fb2c1 --- /dev/null +++ b/docs/pdGuideDB/ltwdump.adoc @@ -0,0 +1,63 @@ +[[ltwdump]] +== Dumping classes during load-time weaving + +[[ltwdump-introduction]] +=== Introduction + +Very rarely problems may be encountered with classes that have been +load-time woven. Symptoms will include incorrect program function or a +Java exception such as `java.lang.VerifyError`. In these situations it's +most helpful to include the offending class in the bug report. When +using load-time weaving the woven classes are in memory only so to save +them to disk configure `META-INF/aop.xml` to dump the classes (by +default to an `_ajdump` subdirectory of the current working directory). +Also if the input class file is not available (e.g. it is a generated +proxy or has already been instrumented by another agent) you can +configure the weaver to dump the input classes as well. + +[[ltw-examples]] +==== Configuring bytecode dumping in load-time weaving + +For details of how to configure byte-code dumping, see the AspectJ +Development Environment Guide section on +xref:../devguide/ltw-configuration.html#configuring-load-time-weaving-with-aopxml-files[Configuring +Load-time Weaving]. Following is a simple example. + +[[ltwdump-examples]] +==== LTW Dump Examples + +The following `META-INF/aop.xml` will weave classes in the `com.foo` +package (and subpackages) but not CGLIB generated classes in the +`com.foo.bar` package (and subpackages). It will also ensure all woven +byte-code is dumped both before and after weaving. + +.... +<aspectj> + <aspects> + <aspect name="ataspectj.EmptyAspect"/> + </aspects> + <weaver options="-verbose -debug"> + <dump within="com.foo.bar..*" beforeandafter="true"/> + <include within="com.foo..*"/> + <exclude within="com.foo.bar..*CGLIB*"/> + </weaver> +</aspectj> +.... + +You should see messages similar to this: + +.... +[WeavingURLClassLoader] info AspectJ Weaver Version 1.5.3 built on Thursday Oct 26, 2006 at 17:22:31 GMT +[WeavingURLClassLoader] info register classloader org.aspectj.weaver.loadtime.WeavingURLClassLoader +[WeavingURLClassLoader] info using configuration /C:/tempMETA-INF/aop.xml +[WeavingURLClassLoader] info register aspect ataspectj.EmptyAspect +[WeavingURLClassLoader] debug not weaving 'com.foo.bar.Test$$EnhancerByCGLIB$$12345' +[WeavingURLClassLoader] debug weaving 'com.foo.bar.Test' +.... + +On disk you would find the following files: + +.... +_ajdump/_before/com/foo/bar/Test.class +_ajdump/com/foo/bar/Test.class +.... |