Mega Code Archive
Counts down from a specified value the number of bytes actually read from the wrapped InputStream
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/* Copyright (c) 2001-2009, The HSQL Development Group
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*
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*
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import java.io.IOException;
import java.io.InputStream;
/**
* Counts down from a specified value the number of bytes actually read
* from the wrapped InputStream.
*
* Returns minus one (-1) early from readXXX methods if the count
* down reaches zero (0) before the end of the wrapped InputStream
* is encountered.
*
* This class is especially useful when a fixed number of bytes is to be read
* from an InputStream that is in turn to be used as the source for an
* {@link java.io.InputStreamReader InputStreamReader}.
*
* @author boucherb@users
* @version 1.8.x
* @since 1.8.x
*/
public final class CountdownInputStream extends InputStream {
private long count;
private InputStream input;
public CountdownInputStream(final InputStream is) {
this.input = is;
}
public int read() throws IOException {
if (this.count <= 0) {
return -1;
}
final int b = this.input.read();
if (b >= 0) {
this.count--;
}
return b;
}
public int read(final byte[] buf) throws IOException {
if (this.count <= 0) {
return -1;
}
int len = buf.length;
if (len > this.count) {
len = (int) this.count;
}
final int r = this.input.read(buf, 0, len);
if (r > 0) {
this.count -= r;
}
return r;
}
public int read(final byte[] buf, final int off,
int len) throws IOException {
if (this.count <= 0) {
return -1;
}
if (len > this.count) {
len = (int) this.count;
}
final int r = this.input.read(buf, 0, len);
if (r > 0) {
this.count -= r;
}
return r;
}
public void close() throws IOException {
this.input.close();
}
public long getCount() {
return this.count;
}
public void setCount(long count) {
this.count = count;
}
}
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