/*
* This file is part of the Wayback archival access software
* (http://archive-access.sourceforge.net/projects/wayback/).
*
* Licensed to the Internet Archive (IA) by one or more individual
* contributors.
*
* The IA 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.archive.wayback.replay.charset;
import java.io.IOException;
import org.archive.wayback.core.Resource;
import org.archive.wayback.core.WaybackRequest;
/**
* @author brad
*
* Provides a way to rotate through several detection schemes
*/
public class RotatingCharsetDetector extends CharsetDetector {
public final static int MODES[][] = {
{0,1,2},
{0,2,1},
{1,0,2},
{1,2,0},
{2,1,0},
{2,0,1}
};
public final static int MODE_COUNT = 6;
public final static int GUESS_TYPES = 3;
public int nextMode(int curMode) {
if(curMode >= MODE_COUNT - 1) {
return 0;
}
return curMode + 1;
}
public String getCharsetType(Resource resource, int type) throws IOException {
if(type == 0) {
return getCharsetFromHeaders(resource);
} else if(type == 1) {
return getCharsetFromMeta(resource);
} else if(type == 2) {
return getCharsetFromBytes(resource);
}
return null;
}
public String getCharset(Resource resource, int mode) throws IOException {
String charset = null;
if(mode >= MODE_COUNT) {
mode = 0;
}
for(int type = 0; type < GUESS_TYPES; type++) {
charset = getCharsetType(resource,MODES[mode][type]);
if(charset != null) {
break;
}
}
if(charset == null) {
charset = DEFAULT_CHARSET;
}
return charset;
}
@Override
public String getCharset(Resource resource, WaybackRequest request)
throws IOException {
int mode = request.getCharsetMode();
return getCharset(resource,mode);
}
}