/*
* Copyright 2002-2014 the original author or authors.
*
* 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.springframework.core.type.filter;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.type.ClassMetadata;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
/**
* Type filter that is aware of traversing over hierarchy.
*
* <p>This filter is useful when matching needs to be made based on potentially the
* whole class/interface hierarchy. The algorithm employed uses a succeed-fast
* strategy: if at any time a match is declared, no further processing is
* carried out.
*
* @author Ramnivas Laddad
* @author Mark Fisher
* @since 2.5
*/
public abstract class AbstractTypeHierarchyTraversingFilter implements TypeFilter {
protected final Log logger = LogFactory.getLog(getClass());
private final boolean considerInherited;
private final boolean considerInterfaces;
protected AbstractTypeHierarchyTraversingFilter(boolean considerInherited, boolean considerInterfaces) {
this.considerInherited = considerInherited;
this.considerInterfaces = considerInterfaces;
}
@Override
public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory)
throws IOException {
// This method optimizes avoiding unnecessary creation of ClassReaders
// as well as visiting over those readers.
if (matchSelf(metadataReader)) {
return true;
}
ClassMetadata metadata = metadataReader.getClassMetadata();
if (matchClassName(metadata.getClassName())) {
return true;
}
if (this.considerInherited) {
if (metadata.hasSuperClass()) {
// Optimization to avoid creating ClassReader for super class.
Boolean superClassMatch = matchSuperClass(metadata.getSuperClassName());
if (superClassMatch != null) {
if (superClassMatch.booleanValue()) {
return true;
}
}
else {
// Need to read super class to determine a match...
try {
if (match(metadata.getSuperClassName(), metadataReaderFactory)) {
return true;
}
}
catch (IOException ex) {
logger.debug("Could not read super class [" + metadata.getSuperClassName() +
"] of type-filtered class [" + metadata.getClassName() + "]");
}
}
}
}
if (this.considerInterfaces) {
for (String ifc : metadata.getInterfaceNames()) {
// Optimization to avoid creating ClassReader for super class
Boolean interfaceMatch = matchInterface(ifc);
if (interfaceMatch != null) {
if (interfaceMatch.booleanValue()) {
return true;
}
}
else {
// Need to read interface to determine a match...
try {
if (match(ifc, metadataReaderFactory)) {
return true;
}
}
catch (IOException ex) {
logger.debug("Could not read interface [" + ifc + "] for type-filtered class [" +
metadata.getClassName() + "]");
}
}
}
}
return false;
}
private boolean match(String className, MetadataReaderFactory metadataReaderFactory) throws IOException {
return match(metadataReaderFactory.getMetadataReader(className), metadataReaderFactory);
}
/**
* Override this to match self characteristics alone. Typically,
* the implementation will use a visitor to extract information
* to perform matching.
*/
protected boolean matchSelf(MetadataReader metadataReader) {
return false;
}
/**
* Override this to match on type name.
*/
protected boolean matchClassName(String className) {
return false;
}
/**
* Override this to match on super type name.
*/
protected Boolean matchSuperClass(String superClassName) {
return null;
}
/**
* Override this to match on interface type name.
*/
protected Boolean matchInterface(String interfaceName) {
return null;
}
}