+++ /dev/null
-package org.apache.lucene.util;
-
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You 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.
- */
-
-import java.io.Serializable;
-import java.lang.reflect.Field;
-import java.lang.reflect.Modifier;
-import java.lang.ref.WeakReference;
-import java.util.LinkedList;
-
-import org.apache.lucene.analysis.tokenattributes.CharTermAttributeImpl; // deprecated
-
-/**
- * Base class for Attributes that can be added to a
- * {@link org.apache.lucene.util.AttributeSource}.
- * <p>
- * Attributes are used to add data in a dynamic, yet type-safe way to a source
- * of usually streamed objects, e. g. a {@link org.apache.lucene.analysis.TokenStream}.
- */
-public abstract class AttributeImpl implements Cloneable, Serializable, Attribute {
- /**
- * Clears the values in this AttributeImpl and resets it to its
- * default value. If this implementation implements more than one Attribute interface
- * it clears all.
- */
- public abstract void clear();
-
- /**
- * Returns a string representation of the object. In general, the {@code toString} method
- * returns a string that "textually represents" this object.
- *
- * <p><b>WARNING:</b> For backwards compatibility this method is implemented as
- * {@code return reflectAsString(false)}. In Lucene 4.0 this default implementation
- * will be removed. The reason for this is the problem of
- * {@link CharTermAttributeImpl#toString} that must return a string representation
- * of the term's char sequence.
- *
- * <p>It is recommeneded to use {@link #reflectAsString} or {@link #reflectWith}
- * to get a well-defined output of AttributeImpl's internals.
- */
- // TODO: @deprecated remove this method in 4.0
- @Override
- public String toString() {
- return reflectAsString(false);
- }
-
- /**
- * This method returns the current attribute values as a string in the following format
- * by calling the {@link #reflectWith(AttributeReflector)} method:
- *
- * <ul>
- * <li><em>iff {@code prependAttClass=true}:</em> {@code "AttributeClass#key=value,AttributeClass#key=value"}
- * <li><em>iff {@code prependAttClass=false}:</em> {@code "key=value,key=value"}
- * </ul>
- *
- * @see #reflectWith(AttributeReflector)
- * @see #toString()
- */
- public final String reflectAsString(final boolean prependAttClass) {
- final StringBuilder buffer = new StringBuilder();
- reflectWith(new AttributeReflector() {
- public void reflect(Class<? extends Attribute> attClass, String key, Object value) {
- if (buffer.length() > 0) {
- buffer.append(',');
- }
- if (prependAttClass) {
- buffer.append(attClass.getName()).append('#');
- }
- buffer.append(key).append('=').append((value == null) ? "null" : value);
- }
- });
- return buffer.toString();
- }
-
- /**
- * @deprecated this will be removed in Lucene 4.0
- */
- @Deprecated
- private static final VirtualMethod<AttributeImpl> toStringMethod =
- new VirtualMethod<AttributeImpl>(AttributeImpl.class, "toString");
-
- /**
- * When {@code true} (default), if a subclass overrides {@link #toString()},
- * its output is parsed by {@link #reflectWith} and used for attribute reflection.
- * This is added to enable attribute implementations from Lucene 2.9 or 3.0 to
- * work correctly with reflection.
- * @deprecated this will be removed in Lucene 4.0.
- */
- @Deprecated
- protected boolean enableBackwards = true;
-
- /**
- * @deprecated this will be removed in Lucene 4.0
- */
- @Deprecated
- private boolean assertExternalClass(Class<? extends AttributeImpl> clazz) {
- final String name = clazz.getName();
- return (!name.startsWith("org.apache.lucene.") && !name.startsWith("org.apache.solr."))
- || name.equals("org.apache.lucene.util.TestAttributeSource$TestAttributeImpl");
- }
-
- /**
- * This method is for introspection of attributes, it should simply
- * add the key/values this attribute holds to the given {@link AttributeReflector}.
- *
- * <p>The default implementation calls {@link AttributeReflector#reflect} for all
- * non-static fields from the implementing class, using the field name as key
- * and the field value as value. The Attribute class is also determined by reflection.
- * Please note that the default implementation can only handle single-Attribute
- * implementations.
- *
- * <p>Custom implementations look like this (e.g. for a combined attribute implementation):
- * <pre>
- * public void reflectWith(AttributeReflector reflector) {
- * reflector.reflect(CharTermAttribute.class, "term", term());
- * reflector.reflect(PositionIncrementAttribute.class, "positionIncrement", getPositionIncrement());
- * }
- * </pre>
- *
- * <p>If you implement this method, make sure that for each invocation, the same set of {@link Attribute}
- * interfaces and keys are passed to {@link AttributeReflector#reflect} in the same order, but possibly
- * different values. So don't automatically exclude e.g. {@code null} properties!
- *
- * @see #reflectAsString(boolean)
- */
- public void reflectWith(AttributeReflector reflector) {
- final Class<? extends AttributeImpl> clazz = this.getClass();
- final LinkedList<WeakReference<Class<? extends Attribute>>> interfaces = AttributeSource.getAttributeInterfaces(clazz);
- if (interfaces.size() != 1) {
- throw new UnsupportedOperationException(clazz.getName() +
- " implements more than one Attribute interface, the default reflectWith() implementation cannot handle this.");
- }
- final Class<? extends Attribute> interf = interfaces.getFirst().get();
-
- // TODO: @deprecated sophisticated(TM) backwards
- if (enableBackwards && toStringMethod.isOverriddenAsOf(clazz)) {
- assert assertExternalClass(clazz) : "no Lucene/Solr classes should fallback to toString() parsing";
- // this class overrides toString and for backwards compatibility we try to parse the string returned by this method:
- for (String part : toString().split(",")) {
- final int pos = part.indexOf('=');
- if (pos < 0) {
- throw new UnsupportedOperationException("The backwards compatibility layer to support reflectWith() " +
- "on old AtributeImpls expects the toString() implementation to return a correct format as specified for method reflectAsString(false)");
- }
- reflector.reflect(interf, part.substring(0, pos).trim(), part.substring(pos + 1));
- }
- return;
- }
- // end sophisticated(TM) backwards
-
- final Field[] fields = clazz.getDeclaredFields();
- try {
- for (int i = 0; i < fields.length; i++) {
- final Field f = fields[i];
- if (Modifier.isStatic(f.getModifiers())) continue;
- f.setAccessible(true);
- reflector.reflect(interf, f.getName(), f.get(this));
- }
- } catch (IllegalAccessException e) {
- // this should never happen, because we're just accessing fields
- // from 'this'
- throw new RuntimeException(e);
- }
- }
-
- /**
- * Copies the values from this Attribute into the passed-in
- * target attribute. The target implementation must support all the
- * Attributes this implementation supports.
- */
- public abstract void copyTo(AttributeImpl target);
-
- /**
- * Shallow clone. Subclasses must override this if they
- * need to clone any members deeply,
- */
- @Override
- public Object clone() {
- Object clone = null;
- try {
- clone = super.clone();
- } catch (CloneNotSupportedException e) {
- throw new RuntimeException(e); // shouldn't happen
- }
- return clone;
- }
-}
fnp / pylucene.git / blobdiff