/**
* 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.
*/
package org.apache.hadoop.gateway.filter.rewrite.api;
import org.apache.hadoop.gateway.filter.rewrite.i18n.UrlRewriteMessages;
import org.apache.hadoop.gateway.filter.rewrite.impl.UrlRewriteContextImpl;
import org.apache.hadoop.gateway.filter.rewrite.impl.UrlRewriteFunctionProcessorFactory;
import org.apache.hadoop.gateway.filter.rewrite.impl.UrlRewriteRuleProcessorHolder;
import org.apache.hadoop.gateway.filter.rewrite.impl.UrlRewriteStepProcessorHolder;
import org.apache.hadoop.gateway.filter.rewrite.spi.UrlRewriteContext;
import org.apache.hadoop.gateway.filter.rewrite.spi.UrlRewriteFunctionProcessor;
import org.apache.hadoop.gateway.filter.rewrite.spi.UrlRewriteStepStatus;
import org.apache.hadoop.gateway.i18n.messages.MessagesFactory;
import org.apache.hadoop.gateway.util.urltemplate.Matcher;
import org.apache.hadoop.gateway.util.urltemplate.Resolver;
import org.apache.hadoop.gateway.util.urltemplate.Template;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
import static org.apache.hadoop.gateway.filter.rewrite.api.UrlRewriter.Direction.IN;
import static org.apache.hadoop.gateway.filter.rewrite.api.UrlRewriter.Direction.OUT;
public class UrlRewriteProcessor implements UrlRewriter {
private static final UrlRewriteMessages LOG = MessagesFactory.get( UrlRewriteMessages.class );
UrlRewriteEnvironment environment;
UrlRewriteRulesDescriptor descriptor;
Map<String,UrlRewriteRuleProcessorHolder> rules = new HashMap<String,UrlRewriteRuleProcessorHolder>();
Matcher<UrlRewriteRuleProcessorHolder> inbound = new Matcher<UrlRewriteRuleProcessorHolder>();
Matcher<UrlRewriteRuleProcessorHolder> outbound = new Matcher<UrlRewriteRuleProcessorHolder>();
Map<String,UrlRewriteFunctionProcessor> functions = new HashMap<String,UrlRewriteFunctionProcessor>();
public UrlRewriteProcessor() {
}
// Convert the descriptor into processors.
public void initialize( UrlRewriteEnvironment environment, UrlRewriteRulesDescriptor descriptor ) {
this.environment = environment;
this.descriptor = descriptor;
initializeFunctions( descriptor );
initializeRules( descriptor );
}
public UrlRewriteRulesDescriptor getConfig() {
return descriptor;
}
@SuppressWarnings("unchecked")
private void initializeFunctions( UrlRewriteRulesDescriptor rules ) {
for( String name : UrlRewriteFunctionDescriptorFactory.getNames() ) {
try {
UrlRewriteFunctionDescriptor descriptor = rules.getFunction( name );
UrlRewriteFunctionProcessor processor = UrlRewriteFunctionProcessorFactory.create( name, descriptor );
processor.initialize( environment, descriptor );
functions.put( name, processor );
} catch( Exception e ) {
// Ignore it and it won't be available as a function.
LOG.failedToInitializeRewriteFunctions( e );
}
}
}
private void initializeRules( UrlRewriteRulesDescriptor descriptor ) {
for( UrlRewriteRuleDescriptor ruleDescriptor : descriptor.getRules() ) {
try {
UrlRewriteRuleProcessorHolder ruleProcessor = new UrlRewriteRuleProcessorHolder();
ruleProcessor.initialize( environment, ruleDescriptor );
if( !rules.containsKey( ruleDescriptor.name() ) ) {
rules.put( ruleDescriptor.name(), ruleProcessor );
}
Template template = ruleDescriptor.template();
if( template != null ) {
EnumSet<Direction> directions = ruleDescriptor.directions();
if( directions == null || directions.isEmpty() ) {
inbound.add( template, ruleProcessor );
outbound.add( template, ruleProcessor );
} else if( directions.contains( IN ) ) {
inbound.add( template, ruleProcessor );
} else if ( directions.contains( OUT ) ) {
outbound.add( template, ruleProcessor );
}
}
} catch( Exception e ) {
LOG.failedToInitializeRewriteRules( e );
}
}
}
public void destroy() {
for( UrlRewriteStepProcessorHolder rule : rules.values() ) {
try {
rule.destroy();
} catch ( Exception e ) {
LOG.failedToDestroyRewriteStepProcessor( e );
}
}
for( UrlRewriteFunctionProcessor function : functions.values() ) {
try {
function.destroy();
} catch( Exception e ) {
LOG.failedToDestroyRewriteFunctionProcessor( e );
}
}
}
@Override
public Template rewrite( Resolver resolver, Template inputUri, Direction direction, String ruleName ) {
Template outputUri = inputUri;
UrlRewriteStepProcessorHolder stepHolder = null;
String effectiveRuleName = null;
if( ruleName == null || "*".equals( ruleName ) ) {
ruleName = null; // Used for logging later.
Matcher<UrlRewriteRuleProcessorHolder>.Match match = null;
switch( direction ) {
case IN:
match = inbound.match( outputUri );
break;
case OUT:
match = outbound.match( outputUri );
break;
}
if( match != null ) {
stepHolder = match.getValue();
effectiveRuleName = match.getValue().getRuleName();
}
} else if( !ruleName.isEmpty() ) {
stepHolder = rules.get( ruleName );
effectiveRuleName = ruleName;
}
if( stepHolder != null ) {
UrlRewriteContext context = new UrlRewriteContextImpl( environment, resolver, functions, direction, inputUri );
try {
UrlRewriteStepStatus stepStatus = stepHolder.process( context );
if( UrlRewriteStepStatus.SUCCESS == stepStatus ) {
outputUri = context.getCurrentUrl();
if( ruleName == null ) {
LOG.rewroteUrlViaImplicitRule( inputUri, direction, effectiveRuleName, outputUri );
} else {
LOG.rewroteUrlViaExplicitRule( inputUri, direction, effectiveRuleName, outputUri );
}
} else {
LOG.failedToRewriteUrl( inputUri, direction, effectiveRuleName, stepStatus );
outputUri = null;
}
} catch( Exception e ) {
LOG.failedToRewriteUrlDueToException( inputUri, direction, effectiveRuleName, e );
outputUri = null;
}
} else {
LOG.noRuleMatchingUrl( inputUri, direction );
}
return outputUri;
}
}