/*
* JBoss, Home of Professional Open Source
* Copyright 2009, Red Hat, Inc. and/or its affiliates, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.hibernate.validator.engine.groups;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.validation.GroupDefinitionException;
import javax.validation.GroupSequence;
import javax.validation.ValidationException;
/**
* Helper class used to resolve groups and sequences into a single chain of groups which can then be validated.
*
* @author Hardy Ferentschik
* @author Kevin Pollet - SERLI - (kevin.pollet@serli.com)
*/
public class GroupChainGenerator {
private final ConcurrentMap<Class<?>, List<Group>> resolvedSequences = new ConcurrentHashMap<Class<?>, List<Group>>();
/**
* Generates a chain of groups to be validated given the specified validation groups.
*
* @param groups The groups specified at the validation call.
*
* @return an instance of {@code GroupChain} defining the order in which validation has to occur.
*/
public GroupChain getGroupChainFor(Collection<Class<?>> groups) {
if ( groups == null || groups.size() == 0 ) {
throw new IllegalArgumentException( "At least one groups has to be specified." );
}
for ( Class<?> clazz : groups ) {
if ( !clazz.isInterface() ) {
throw new ValidationException( "A group has to be an interface. " + clazz.getName() + " is not." );
}
}
GroupChain chain = new GroupChain();
for ( Class<?> clazz : groups ) {
if ( isGroupSequence( clazz ) ) {
insertSequence( clazz, chain );
}
else {
Group group = new Group( clazz );
chain.insertGroup( group );
insertInheritedGroups( clazz, chain );
}
}
return chain;
}
private boolean isGroupSequence(Class<?> clazz) {
return clazz.getAnnotation( GroupSequence.class ) != null;
}
/**
* Recursively add inherited groups into the group chain.
*
* @param clazz The group interface
* @param chain The group chain we are currently building.
*/
private void insertInheritedGroups(Class<?> clazz, GroupChain chain) {
for ( Class<?> inheritedGroup : clazz.getInterfaces() ) {
Group group = new Group( inheritedGroup );
chain.insertGroup( group );
insertInheritedGroups( inheritedGroup, chain );
}
}
private void insertSequence(Class<?> clazz, GroupChain chain) {
List<Group> sequence = resolvedSequences.get( clazz );
if ( sequence == null ) {
sequence = resolveSequence( clazz, new ArrayList<Class<?>>() );
// we expand the inherited groups only after we determined whether the sequence is expandable
sequence = expandInheritedGroups( sequence );
// cache already resolved sequences
final List<Group> cachedResolvedSequence = resolvedSequences.putIfAbsent( clazz, sequence );
if ( cachedResolvedSequence != null ) {
sequence = cachedResolvedSequence;
}
}
chain.insertSequence( sequence );
}
private List<Group> expandInheritedGroups(List<Group> sequence) {
List<Group> expandedGroup = new ArrayList<Group>();
for ( Group group : sequence ) {
expandedGroup.add( group );
addInheritedGroups( group, expandedGroup );
}
return expandedGroup;
}
private void addInheritedGroups(Group group, List<Group> expandedGroups) {
for ( Class<?> inheritedGroup : group.getGroup().getInterfaces() ) {
if ( isGroupSequence( inheritedGroup ) ) {
throw new GroupDefinitionException(
"Sequence definitions are not allowed as composing parts of a sequence."
);
}
Group g = new Group( inheritedGroup, group.getSequence() );
expandedGroups.add( g );
addInheritedGroups( g, expandedGroups );
}
}
private List<Group> resolveSequence(Class<?> group, List<Class<?>> processedSequences) {
if ( processedSequences.contains( group ) ) {
throw new GroupDefinitionException( "Cyclic dependency in groups definition" );
}
else {
processedSequences.add( group );
}
List<Group> resolvedGroupSequence = new ArrayList<Group>();
GroupSequence sequenceAnnotation = group.getAnnotation( GroupSequence.class );
Class<?>[] sequenceArray = sequenceAnnotation.value();
for ( Class<?> clazz : sequenceArray ) {
if ( isGroupSequence( clazz ) ) {
List<Group> tmpSequence = resolveSequence( clazz, processedSequences );
addGroups( resolvedGroupSequence, tmpSequence );
}
else {
List<Group> list = new ArrayList<Group>();
list.add( new Group( clazz, group ) );
addGroups( resolvedGroupSequence, list );
}
}
return resolvedGroupSequence;
}
private void addGroups(List<Group> resolvedGroupSequence, List<Group> groups) {
for ( Group tmpGroup : groups ) {
if ( resolvedGroupSequence.contains( tmpGroup ) && resolvedGroupSequence.indexOf( tmpGroup ) < resolvedGroupSequence
.size() - 1 ) {
throw new GroupDefinitionException( "Unable to expand group sequence." );
}
resolvedGroupSequence.add( tmpGroup );
}
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append( "GroupChainGenerator" );
sb.append( "{resolvedSequences=" ).append( resolvedSequences );
sb.append( '}' );
return sb.toString();
}
}