com.google.common.io.CountingInputStream Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* Copyright (C) 2007 The Guava Authors
*
* Licensed 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 com.google.common.io;
import static com.google.common.base.Preconditions.checkNotNull;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtIncompatible;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* An {@link InputStream} that counts the number of bytes read.
*
* @author Chris Nokleberg
* @since 1.0
*/
@Beta
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class CountingInputStream extends FilterInputStream {
private long count;
private long mark = -1;
/**
* Wraps another input stream, counting the number of bytes read.
*
* @param in the input stream to be wrapped
*/
public CountingInputStream(InputStream in) {
super(checkNotNull(in));
}
/** Returns the number of bytes read. */
public long getCount() {
return count;
}
@Override
public int read() throws IOException {
int result = in.read();
if (result != -1) {
count++;
}
return result;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
int result = in.read(b, off, len);
if (result != -1) {
count += result;
}
return result;
}
@Override
public long skip(long n) throws IOException {
long result = in.skip(n);
count += result;
return result;
}
@Override
public synchronized void mark(int readlimit) {
in.mark(readlimit);
mark = count;
// it's okay to mark even if mark isn't supported, as reset won't work
}
@Override
public synchronized void reset() throws IOException {
if (!in.markSupported()) {
throw new IOException("Mark not supported");
}
if (mark == -1) {
throw new IOException("Mark not set");
}
in.reset();
count = mark;
}
}