org.apache.tika.parser.txt.UniversalEncodingDetector Maven / Gradle / Ivy
/*
* 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.tika.parser.txt;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;
import org.apache.tika.detect.EncodingDetector;
import org.apache.tika.metadata.Metadata;
public class UniversalEncodingDetector implements EncodingDetector {
private static final int BUFSIZE = 1024;
private static final int LOOKAHEAD = 16 * BUFSIZE;
public Charset detect(InputStream input, Metadata metadata)
throws IOException {
if (input == null) {
return null;
}
input.mark(LOOKAHEAD);
try {
UniversalEncodingListener listener =
new UniversalEncodingListener(metadata);
byte[] b = new byte[BUFSIZE];
int n = 0;
int m = input.read(b);
while (m != -1 && n < LOOKAHEAD && !listener.isDone()) {
n += m;
listener.handleData(b, 0, m);
m = input.read(b, 0, Math.min(b.length, LOOKAHEAD - n));
}
return listener.dataEnd();
} catch (LinkageError e) {
return null; // juniversalchardet is not available
} finally {
input.reset();
}
}
}