/**
* 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.spi.UrlRewriteStreamFilter;
import org.apache.hadoop.gateway.util.MimeTypes;
import org.apache.hadoop.gateway.util.urltemplate.Resolver;
import javax.activation.MimeType;
import javax.activation.MimeTypeParseException;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.ServiceLoader;
public abstract class UrlRewriteStreamFilterFactory {
private static String DEFAULT_CHARACTER_ENCODING = "ISO-8859-1";
private static Map<String,Map<String,UrlRewriteStreamFilter>> MAP = loadFactories();
private UrlRewriteStreamFilterFactory() {
}
public static InputStream create(
MimeType type,
String name,
InputStream stream,
UrlRewriter rewriter,
Resolver resolver,
UrlRewriter.Direction direction,
UrlRewriteFilterContentDescriptor config )
throws IOException {
InputStream filteredStream = null;
Map<String,UrlRewriteStreamFilter> nameMap = getNameMap( type );
UrlRewriteStreamFilter filter = getFilter( nameMap, name );
String charset = MimeTypes.getCharset( type, DEFAULT_CHARACTER_ENCODING );
if( filter != null ) {
filteredStream = filter.filter( stream, charset, rewriter, resolver, direction, config );
}
return filteredStream;
}
private static Map<String,Map<String,UrlRewriteStreamFilter>> loadFactories() {
Map<String,Map<String,UrlRewriteStreamFilter>> typeMap = new HashMap<String,Map<String,UrlRewriteStreamFilter>>();
ServiceLoader<UrlRewriteStreamFilter> filters = ServiceLoader.load( UrlRewriteStreamFilter.class );
for( UrlRewriteStreamFilter filter : filters ) {
String[] types = filter.getTypes();
for( String type: types ) {
Map<String,UrlRewriteStreamFilter> nameMap = typeMap.get( type );
if( nameMap == null ) {
nameMap = new LinkedHashMap<String,UrlRewriteStreamFilter>();
typeMap.put( type, nameMap );
}
for( String name: filter.getNames() ) {
nameMap.put( name, filter );
}
}
}
return typeMap;
}
private static Map<String,UrlRewriteStreamFilter> getNameMap( MimeType type ) {
if( type == null ) {
type = new MimeType();
}
Map<String,UrlRewriteStreamFilter> nameMap = MAP.get( type.getBaseType() );
try {
if( nameMap == null ) {
type.setPrimaryType( "*" );
nameMap = MAP.get( type.getBaseType() );
if( nameMap == null ) {
type.setSubType( "*" );
nameMap = MAP.get( type.getBaseType() );
if( nameMap == null ) {
nameMap = MAP.get( null );
}
}
}
} catch( MimeTypeParseException e ) {
throw new IllegalArgumentException( type.toString(), e );
}
return nameMap;
}
private static UrlRewriteStreamFilter getFilter( Map<String,UrlRewriteStreamFilter> map, String name ) {
UrlRewriteStreamFilter filter = null;
if( map != null ) {
if( name == null && !map.isEmpty() ) {
filter = map.values().iterator().next();
} else {
filter = map.get( name );
}
}
return filter;
}
}