MoparScape/MoparScape/src/main/java/org/moparscape/res/ChecksumInputStream.java

79 lines
2.3 KiB
Java

/*
* Copyright (C) 2009-2013 moparisthebest
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Official forums are http://www.moparscape.org/smf/
* Email me at admin@moparisthebest.com.
*/
package org.moparscape.res;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.CRC32;
import java.util.zip.Checksum;
public class ChecksumInputStream extends FilterInputStream {
private Checksum cs;
/**
* This creates an InputStream that calculates the CRC as bytes are read.
* @param in InputStream to calculate CRC for.
*/
public ChecksumInputStream(InputStream in) {
super(in);
cs = new CRC32();
}
/**
* This creates an InputStream that calculates the CRC as the bytes are read. This constructor is useful if you
* want to calculate the Checksum of numerous InputStreams all calculated together.
* @param in
* @param cs
*/
public ChecksumInputStream(InputStream in, Checksum cs) {
super(in);
this.cs = cs;
}
public long getValue() {
return cs.getValue();
}
@Override
public int read() throws IOException {
int byteValue = super.read();
if (byteValue != -1) cs.update(byteValue);
return byteValue;
}
/*
@Override
public int read(byte[] b) throws IOException {
int bytesRead = super.read(b);
if (bytesRead != -1) cs.update(b, 0, b.length);
return bytesRead;
}
*/
@Override
public int read(byte[] b, int off, int len) throws IOException {
int bytesRead = super.read(b, off, len);
if (bytesRead != -1) cs.update(b, off, bytesRead);
return bytesRead;
}
}