jlibs.core.io.UnicodeInputStream Maven / Gradle / Ivy
/**
* Copyright 2015 Santhosh Kumar Tekuri
*
* The JLibs authors license 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 jlibs.core.io;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
/**
* @author Santhosh Kumar T
*/
public class UnicodeInputStream extends FilterInputStream{
private ByteBuffer marker = ByteBuffer.allocate(4);
public final String encoding;
public final boolean hasBOM;
public UnicodeInputStream(InputStream delegate) throws IOException{
this(delegate, EncodingDetector.DEFAULT);
}
public UnicodeInputStream(InputStream delegate, EncodingDetector detector) throws IOException{
super(delegate);
int len = IOUtil.readFully(delegate, marker.array());
marker.limit(len);
encoding = detector.detect(marker);
hasBOM = marker.position()>0;
if(!marker.hasRemaining())
marker = null;
}
@Override
public int read() throws IOException{
if(marker!=null){
int b = marker.get() & 0xFF;
if(!marker.hasRemaining())
marker = null;
return b;
}else
return super.read();
}
@Override
public int read(byte[] b, int off, int len) throws IOException{
if(marker!=null){
int read = Math.min(marker.remaining(), len);
System.arraycopy(marker.array(), marker.position(), b, off, read);
if(read==marker.remaining())
marker = null;
else
marker.position(marker.position()+read);
return read;
}
return super.read(b, off, len);
}
public InputStreamReader createReader(){
if(encoding==null)
return new InputStreamReader(this);
else
return new InputStreamReader(this, Charset.forName(encoding));
}
}