/*
* Copyright 2010 Impetus Infotech.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.impetus.annovention;
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.jboss.vfs.VirtualFile;
import javassist.bytecode.AnnotationsAttribute;
import javassist.bytecode.ClassFile;
import javassist.bytecode.FieldInfo;
import javassist.bytecode.MethodInfo;
import javassist.bytecode.annotation.Annotation;
import com.impetus.annovention.listener.ClassAnnotationDiscoveryListener;
import com.impetus.annovention.listener.FieldAnnotationDiscoveryListener;
import com.impetus.annovention.listener.MethodAnnotationDiscoveryListener;
import com.impetus.annovention.resource.ClassFileIterator;
import com.impetus.annovention.resource.JarFileIterator;
import com.impetus.annovention.resource.ResourceIterator;
/**
* Base annotation discoverer.
*
* @author animesh.kumar
*/
public abstract class Discoverer {
/** map to hold ClassAnnotation listeners */
private final Map<String, Set<ClassAnnotationDiscoveryListener>> classAnnotationListeners =
new HashMap<String, Set<ClassAnnotationDiscoveryListener>>();
/** map to hold FieldAnnotation listeners */
private final Map<String, Set<FieldAnnotationDiscoveryListener>> fieldAnnotationListeners =
new HashMap<String, Set<FieldAnnotationDiscoveryListener>>();
/** map to hold MethodAnnotation listeners */
private final Map<String, Set<MethodAnnotationDiscoveryListener>> methodAnnotationListeners =
new HashMap<String, Set<MethodAnnotationDiscoveryListener>>();
/**
* Instantiates a new Discoverer.
*/
public Discoverer() {
}
/**
* Adds ClassAnnotationDiscoveryListener
*
* @param listener
*/
public final void addAnnotationListener (ClassAnnotationDiscoveryListener listener) {
addAnnotationListener (classAnnotationListeners, listener, listener.supportedAnnotations());
}
/**
* Adds FieldAnnotationDiscoveryListener
*
* @param listener
*/
public final void addAnnotationListener (FieldAnnotationDiscoveryListener listener) {
addAnnotationListener (fieldAnnotationListeners, listener, listener.supportedAnnotations());
}
/**
* Adds MethodAnnotationDiscoveryListener
*
* @param listener
*/
public final void addAnnotationListener (MethodAnnotationDiscoveryListener listener) {
addAnnotationListener (methodAnnotationListeners, listener, listener.supportedAnnotations());
}
/**
* Helper class to find supported annotations of a listener and register them
*
* @param <L>
* @param map
* @param listener
* @param annotations
*/
private <L> void addAnnotationListener (Map<String, Set<L>> map, L listener, String... annotations) {
// throw exception if the listener doesn't support any annotations. what's the point of
// registering then?
if (null == annotations || annotations.length == 0) {
throw new IllegalArgumentException(listener.getClass() + " has no supporting Annotations. Check method supportedAnnotations");
}
for (String annotation : annotations) {
Set<L> listeners = map.get(annotation);
if (null == listeners) {
listeners = new HashSet<L>();
map.put(annotation, listeners);
}
listeners.add(listener);
}
}
/**
* Gets the filter implementation.
*
* @return the filter
*/
public abstract Filter getFilter();
/**
* Finds resources to scan for
*
* @return Array of URLs
*/
public abstract URL[] findResources(ClassLoader cl);
/**
* that's my buddy! this is where all the discovery starts.
* @param cl
*/
public final void discover(ClassLoader cl) {
Set<String> processedAlready = new HashSet<String>();
URL[] resources = findResources(cl);
for (URL resource : resources) {
if(processedAlready.contains(resource.getPath()))
continue;
processedAlready.add(resource.getPath());
try {
ResourceIterator itr = getResourceIterator(resource, getFilter());
InputStream is = null;
while ((is = itr.next()) != null) {
// make a data input stream
DataInputStream dstream = new DataInputStream(new BufferedInputStream(is));
try {
// get java-assist class file
ClassFile classFile = new ClassFile(dstream);
// discover class-level annotations
discoverAndIntimateForClassAnnotations (classFile);
// discover field annotations
discoverAndIntimateForFieldAnnotations (classFile);
// discover method annotations
discoverAndIntimateForMethodAnnotations(classFile);
} finally {
dstream.close();
is.close();
}
}
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
/**
* Discovers Class Annotations
*
* @param classFile
*/
private void discoverAndIntimateForClassAnnotations (ClassFile classFile) {
Set<Annotation> annotations = new HashSet<Annotation>();
AnnotationsAttribute visible = (AnnotationsAttribute) classFile.getAttribute(AnnotationsAttribute.visibleTag);
AnnotationsAttribute invisible = (AnnotationsAttribute) classFile.getAttribute(AnnotationsAttribute.invisibleTag);
if (visible != null) {
annotations.addAll(Arrays.asList(visible.getAnnotations()));
}
if (invisible != null) {
annotations.addAll(Arrays.asList(invisible.getAnnotations()));
}
// now tell listeners
for (Annotation annotation : annotations) {
Set<ClassAnnotationDiscoveryListener> listeners = classAnnotationListeners.get(annotation.getTypeName());
if (null == listeners) {
continue;
}
for (ClassAnnotationDiscoveryListener listener : listeners) {
listener.discovered(classFile.getName(), annotation.getTypeName());
}
}
}
/**
* Discovers Field Annotations
*
* @param classFile
*/
private void discoverAndIntimateForFieldAnnotations (ClassFile classFile) {
@SuppressWarnings("unchecked")
List<FieldInfo> fields = classFile.getFields();
if (fields == null) {
return;
}
for (FieldInfo fieldInfo : fields) {
Set<Annotation> annotations = new HashSet<Annotation>();
AnnotationsAttribute visible = (AnnotationsAttribute) fieldInfo.getAttribute(AnnotationsAttribute.visibleTag);
AnnotationsAttribute invisible = (AnnotationsAttribute) fieldInfo.getAttribute(AnnotationsAttribute.invisibleTag);
if (visible != null) {
annotations.addAll(Arrays.asList(visible.getAnnotations()));
}
if (invisible != null) {
annotations.addAll(Arrays.asList(invisible.getAnnotations()));
}
// now tell listeners
for (Annotation annotation : annotations) {
Set<FieldAnnotationDiscoveryListener> listeners = fieldAnnotationListeners.get(annotation.getTypeName());
if (null == listeners) {
continue;
}
for (FieldAnnotationDiscoveryListener listener : listeners) {
listener.discovered(classFile.getName(), fieldInfo.getName(), annotation.getTypeName());
}
}
}
}
/**
* Discovers Method Annotations
*
* @param classFile
*/
private void discoverAndIntimateForMethodAnnotations(ClassFile classFile) {
@SuppressWarnings("unchecked")
List<MethodInfo> methods = classFile.getMethods();
if (methods == null) {
return;
}
for (MethodInfo methodInfo : methods) {
Set<Annotation> annotations = new HashSet<Annotation>();
AnnotationsAttribute visible = (AnnotationsAttribute) methodInfo.getAttribute(AnnotationsAttribute.visibleTag);
AnnotationsAttribute invisible = (AnnotationsAttribute) methodInfo.getAttribute(AnnotationsAttribute.invisibleTag);
if (visible != null) {
annotations.addAll(Arrays.asList(visible.getAnnotations()));
}
if (invisible != null) {
annotations.addAll(Arrays.asList(invisible.getAnnotations()));
}
// now tell listeners
for (Annotation annotation : annotations) {
Set<MethodAnnotationDiscoveryListener> listeners = methodAnnotationListeners.get(annotation.getTypeName());
if (null == listeners) {
continue;
}
for (MethodAnnotationDiscoveryListener listener : listeners) {
listener.discovered(classFile.getName(), methodInfo.getName(), methodInfo.getDescriptor(), annotation.getTypeName());
}
}
}
}
/**
* Gets the Resource iterator for URL with Filter.
*
* @param url
* @param filter
* @return
* @throws IOException
*/
private ResourceIterator getResourceIterator(URL resource, Filter filter) throws IOException {
URL url = resource;
String urlString = url.toString();
if (urlString.endsWith("!/")) {
//It must be a jar file since it has the !/
urlString = urlString.substring(4);
urlString = urlString.substring(0, urlString.length() - 2);
url = new URL(urlString);
return new JarFileIterator(url.openStream(), filter);
} else if (url.getProtocol().equals("file")) {
String path = url.getPath();
String newPath = path.replace((CharSequence)"%2520", " ");
File f = new File(newPath);
if (f.isDirectory()) {
return new ClassFileIterator(f, filter);
} else {
throw new RuntimeException("bug, how is this not a directory="+f.getAbsolutePath());
}
} else if (url.getProtocol().equals("vfs")) {
URLConnection conn = new URL(urlString).openConnection();
VirtualFile vf = (VirtualFile) conn.getContent();
File contentsFile = vf.getPhysicalFile();
File dir = contentsFile.getParentFile();
String fileName = vf.getName();
File physicalFile = new File(dir, fileName);
if (urlString.indexOf("jar") > 0) {
// Its a jar
InputStream is = new FileInputStream(physicalFile);
return new JarFileIterator(is, filter);
} else {
// Its a directory
return new ClassFileIterator(physicalFile, filter);
}
} else {
throw new IOException("Unable to understand protocol: " + resource.getProtocol());
}
}
}