org.ocpsoft.rewrite.annotation.scan

Class ByteCodeFilter

java.lang.Object

org.ocpsoft.rewrite.annotation.scan.ByteCodeFilter

public class ByteCodeFilter
extends Object

This class reads Java class files and checks whether they contain references to specific annotations. This allows to check classes for the presence of annotations before instantiating them.

The filter is inspired by the ClassByteCodeAnnotationFilter of Apache MyFaces 2.0. Many thanks go out to Leonardo Uribe for his great work on this class.

Author:

Christian Kaltepoth

See Also:

http://docs.oracle.com/javase/specs/jvms/se5.0/html/ClassFile.doc.html, http://en.wikipedia.org/wiki/Class_%28file_format%29

Constructor Summary

Constructors

Constructor and Description
ByteCodeFilter(Set<Class<? extends Annotation>> types) The filter must be initialized with a list of types to look for when scanning the class files.

Method Summary

Modifier and Type	Method and Description
boolean	accept(InputStream classFileStream) Checks whether that supplied InputStream contains a Java class file that might contain references to specific annotation types.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ByteCodeFilter

public ByteCodeFilter(Set<Class<? extends Annotation>> types)

The filter must be initialized with a list of types to look for when scanning the class files. If a class files contains a reference to one of these types, the filter will accept the class.

Parameters:

types - A Set of types to look for

Method Detail

accept

public boolean accept(InputStream classFileStream)
               throws IOException

Checks whether that supplied InputStream contains a Java class file that might contain references to specific annotation types.

The caller of this method is responsible to close the supplied InputStream. This method won't do it!

Parameters:

classFileStream - The stream to read the class file from.

Returns:

true for files that contain at least one reference to one of the "interesting" annotations

Throws:

IOException - for any kind of IO problem

toString

public String toString()

Overrides:

toString in class Object