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Commons Attributes example source code file (AttributeIndex.java)
The Commons Attributes AttributeIndex.java source code/* * Copyright 2003-2005 The Apache Software Foundation * * 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 org.apache.commons.attributes; import java.io.InputStream; import java.io.InputStreamReader; import java.io.BufferedReader; import java.lang.reflect.Constructor; import java.lang.reflect.Method; import java.lang.reflect.Field; import java.net.URL; import java.net.URLConnection; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.Enumeration; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.StringTokenizer; /** * An index providing a list of elements with given attributes. This * requires that the attribute is {@link Indexed} and that the * attribute indexer tool has been run on the jar file containing the * classes. * * @since 2.1 */ public class AttributeIndex { /** * Reference to a method parameter. A method parameter * is defined by the Method object it is defined in, and the index * of the parameter in the method's parameter list. * * @since 2.1 */ public static class MethodParameter { private final Method method; private final int index; /** * Constructs a new MethodParameter. * * @since 2.1 */ public MethodParameter (Method method, int index) { this.method = method; this.index = index; } /** * Get the method this parameter is defined in. * * @since 2.1 */ public Method getMethod () { return method; } /** * Get the index of this parameter in the parameter list of the method. * * @since 2.1 */ public int getIndex () { return index; } /** * Compares two <code>MethodParameters for equality. * They must point to the same method and have the same index. * * @since 2.1 */ public boolean equals (Object o) { return o != null && o instanceof MethodParameter && method.equals (((MethodParameter) o).method) && index == ((MethodParameter) o).index; } /** * Computes the hashCode. * * @since 2.1 */ public int hashCode () { return method.hashCode () + index; } /** * Converts this method parameter into a human-readable string. * * @since 2.1 */ public String toString () { return method.toString () + ":" + index; } } /** * A constructor parameter. A method parameter * is defined by the Method object it is defined in, and the index * of the parameter in the method's parameter list. * * @since 2.1 */ public static class ConstructorParameter { private final Constructor ctor; private final int index; /** * Constructs a new ConstructorParameter. * * @since 2.1 */ public ConstructorParameter (Constructor ctor, int index) { this.ctor = ctor; this.index = index; } /** * Get the constructor this parameter is defined in. * * @since 2.1 */ public Constructor getConstructor () { return ctor; } /** * Get the index of this parameter in the parameter list of the constructor. * * @since 2.1 */ public int getIndex () { return index; } /** * Compares two <code>ConstructorParameters for equality. * They must point to the same constructor and have the same index. * * @since 2.1 */ public boolean equals (Object o) { return o != null && o instanceof ConstructorParameter && ctor.equals (((ConstructorParameter) o).ctor) && index == ((ConstructorParameter) o).index; } /** * Computes the hashCode. * * @since 2.1 */ public int hashCode () { return ctor.hashCode () + index; } /** * Converts this constructor parameter into a human-readable string. * * @since 2.1 */ public String toString () { return ctor.toString () + ":" + index; } } private static class IndexNode { public Collection classes = new HashSet (); public Collection fields = new HashSet (); public Collection methods = new HashSet (); public Collection constructors = new HashSet (); public Collection returnValues = new HashSet (); public Collection constructorParameters = new HashSet (); public Collection methodParameters = new HashSet (); public void seal () { classes = seal (classes); fields = seal (fields); methods = seal (methods); constructors = seal (constructors); returnValues = seal (returnValues); constructorParameters = seal (constructorParameters); methodParameters = seal (methodParameters); } private Collection seal (Collection coll) { return Collections.unmodifiableCollection (coll); } } private final HashMap index = new HashMap (); private final ClassLoader classLoader; /** * Creates a new AttributeIndex for the given ClassLoader. * * @since 2.1 */ public AttributeIndex (ClassLoader cl) throws Exception { this.classLoader = cl; Enumeration e = cl.getResources ("META-INF/attrs.index"); while (e.hasMoreElements ()) { URL url = (URL) e.nextElement (); loadFromURL (url); } Iterator iter = index.values ().iterator (); while (iter.hasNext ()) { ((IndexNode) iter.next ()).seal (); } } private IndexNode getNode (Class attributeClass) { IndexNode node = (IndexNode) index.get (attributeClass.getName ()); if (node == null) { node = new IndexNode (); index.put (attributeClass.getName (), node); } return node; } private void addIndex (Collection attributes, Class clazz) { Iterator iter = attributes.iterator (); while (iter.hasNext ()) { getNode (iter.next ().getClass ()).classes.add (clazz); } } private void addIndex (Collection attributes, Field field) { Iterator iter = attributes.iterator (); while (iter.hasNext ()) { getNode (iter.next ().getClass ()).fields.add (field); } } private void addIndex (Collection attributes, Method method) { Iterator iter = attributes.iterator (); while (iter.hasNext ()) { getNode (iter.next ().getClass ()).methods.add (method); } } private void addIndex (Collection attributes, Constructor constructor) { Iterator iter = attributes.iterator (); while (iter.hasNext ()) { getNode (iter.next ().getClass ()).constructors.add (constructor); } } private void addReturnIndex (Collection attributes, Method method) { Iterator iter = attributes.iterator (); while (iter.hasNext ()) { getNode (iter.next ().getClass ()).returnValues.add (method); } } private void addIndex (Collection attributes, Method method, int parameter) { Iterator iter = attributes.iterator (); while (iter.hasNext ()) { getNode (iter.next ().getClass ()).methodParameters.add (new MethodParameter (method, parameter)); } } private void addIndex (Collection attributes, Constructor ctor, int parameter) { Iterator iter = attributes.iterator (); while (iter.hasNext ()) { getNode (iter.next ().getClass ()).constructorParameters.add (new ConstructorParameter (ctor, parameter)); } } /** * Add a class to the index. */ private void addClass (String clazzName) throws Exception { Class clazz = classLoader.loadClass (clazzName); // Get the attributes attached to the class itself... Collection coll = Attributes.getAttributes (clazz); coll = AttributeUtil.getObjectsWithAttributeType (coll, Indexed.class); addIndex (coll, clazz); Field[] fields = clazz.getDeclaredFields (); for (int i = 0; i < fields.length; i++) { coll = Attributes.getAttributes (fields[i]); coll = AttributeUtil.getObjectsWithAttributeType (coll, Indexed.class); addIndex (coll, fields[i]); } Method[] methods = clazz.getDeclaredMethods (); for (int i = 0; i < methods.length; i++) { coll = Attributes.getAttributes (methods[i]); coll = AttributeUtil.getObjectsWithAttributeType (coll, Indexed.class); addIndex (coll, methods[i]); // Return values coll = Attributes.getReturnAttributes (methods[i]); coll = AttributeUtil.getObjectsWithAttributeType (coll, Indexed.class); addReturnIndex (coll, methods[i]); // Parameters int numParameters = methods[i].getParameterTypes().length; for (int j = 0; j < numParameters; j++) { coll = Attributes.getParameterAttributes (methods[i], j); coll = AttributeUtil.getObjectsWithAttributeType (coll, Indexed.class); addIndex (coll, methods[i], j); } } Constructor[] ctors = clazz.getDeclaredConstructors (); for (int i = 0; i < ctors.length; i++) { coll = Attributes.getAttributes (ctors[i]); coll = AttributeUtil.getObjectsWithAttributeType (coll, Indexed.class); addIndex (coll, ctors[i]); // Parameters int numParameters = ctors[i].getParameterTypes().length; for (int j = 0; j < numParameters; j++) { coll = Attributes.getParameterAttributes (ctors[i], j); coll = AttributeUtil.getObjectsWithAttributeType (coll, Indexed.class); addIndex (coll, ctors[i], j); } } } /** * Load the attrs.index from a given URL. * * @since 2.1 */ private void loadFromURL (URL url) throws Exception { URLConnection connection = url.openConnection (); BufferedReader br = new BufferedReader (new InputStreamReader (connection.getInputStream ())); try { String currentAttributeClass = null; String line = null; while ((line = br.readLine ()) != null) { if (line.startsWith ("Class: ")) { String className = line.substring ("Class: ".length ()).trim (); addClass (className); } } } finally { br.close (); } } /** * Gets a Collection of the classes that have an attribute of the specified class. * The Collection contains the class names (String). * * @deprecated Use the getClasses(Class) method instead. * * @since 2.1 */ public Collection getClassesWithAttribute (String attributeClass) { if (index.containsKey (attributeClass)) { Collection classes = ((IndexNode) index.get (attributeClass)).classes; Iterator iter = classes.iterator (); Collection converted = new ArrayList (classes.size ()); while (iter.hasNext ()) { converted.add (((Class) iter.next ()).getName ().replace ('$', '.')); } return converted; } else { return Collections.EMPTY_SET; } } /** * Gets a Collection of the classes that have an attribute of the specified class. * The Collection contains the class names (String). * * @deprecated Use the getClasses(Class) method instead. */ public Collection getClassesWithAttribute (Class attributeClass) { return getClassesWithAttribute (attributeClass.getName ()); } /** * Gets a Collection of the <code>Classes that have an attribute of the specified class. * The Collection contains the classes (Class). * * @since 2.1 */ public Collection getClasses (Class attributeClass) { if (index.containsKey (attributeClass.getName ())) { return ((IndexNode) index.get (attributeClass.getName ())).classes; } else { return Collections.EMPTY_SET; } } /** * Gets a Collection of the <code>Methods that have an attribute of the specified class. * The Collection contains the methods (java.lang.reflect.Method). * * @since 2.1 */ public Collection getMethods (Class attributeClass) { if (index.containsKey (attributeClass.getName ())) { return ((IndexNode) index.get (attributeClass.getName ())).methods; } else { return Collections.EMPTY_SET; } } /** * Gets a Collection of the <code>Methods whose return value has an attribute of the specified class. * The Collection contains the methods (java.lang.reflect.Method). * * @since 2.1 */ public Collection getMethodsReturning (Class attributeClass) { if (index.containsKey (attributeClass.getName ())) { return ((IndexNode) index.get (attributeClass.getName ())).returnValues; } else { return Collections.EMPTY_SET; } } /** * Gets a Collection of the <code>Fields that have an attribute of the specified class. * The Collection contains the methods (java.lang.reflect.Field). * * @since 2.1 */ public Collection getFields (Class attributeClass) { if (index.containsKey (attributeClass.getName ())) { return ((IndexNode) index.get (attributeClass.getName ())).fields; } else { return Collections.EMPTY_SET; } } /** * Gets a Collection of the <code>Constructors that have an attribute of the specified class. * The Collection contains the methods (java.lang.reflect.Constructor). * * @since 2.1 */ public Collection getConstructors (Class attributeClass) { if (index.containsKey (attributeClass.getName ())) { return ((IndexNode) index.get (attributeClass.getName ())).constructors; } else { return Collections.EMPTY_SET; } } /** * Gets a Collection of the <code>ConstructorParameters that have an attribute of the specified class. * The Collection contains the methods ({@link AttributeIndex.ConstructorParameter}). * * @since 2.1 */ public Collection getConstructorParameters (Class attributeClass) { if (index.containsKey (attributeClass.getName ())) { return ((IndexNode) index.get (attributeClass.getName ())).constructorParameters; } else { return Collections.EMPTY_SET; } } /** * Gets a Collection of the <code>MethodParameters that have an attribute of the specified class. * The Collection contains the methods ({@link AttributeIndex.MethodParameter}). * * @since 2.1 */ public Collection getMethodParameters (Class attributeClass) { if (index.containsKey (attributeClass.getName ())) { return ((IndexNode) index.get (attributeClass.getName ())).methodParameters; } else { return Collections.EMPTY_SET; } } } Other Commons Attributes examples (source code examples)Here is a short list of links related to this Commons Attributes AttributeIndex.java source code file: |
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