com.groupbyinc.common.util.stream.RestrictedInputStream Maven / Gradle / Ivy
package com.groupbyinc.common.util.stream;
import java.io.IOException;
import java.io.InputStream;
/**
* Restricted {@link InputStream}
* - throw {@link IOException} when original {@link InputStream} exceeds maximum size in bytes
*
* @author Alan Czajkowski
*/
public class RestrictedInputStream extends InputStream {
public static final String EXCEEDED_MAX_BYTES = "InputStream exceeded maximum byte size";
private final InputStream original;
private final long maxBytes;
private long totalBytesRead;
public RestrictedInputStream(InputStream original, long maxBytes) {
this.original = original;
this.maxBytes = maxBytes;
}
@Override
public int read() throws IOException {
int b = original.read();
if (b >= 0) {
incrementByteCounter(1);
}
return b;
}
@Override
public int read(byte b[]) throws IOException {
return read(b, 0, b.length);
}
@Override
public int read(byte b[], int off, int len) throws IOException {
int bytesRead = original.read(b, off, len);
if (bytesRead >= 0) {
incrementByteCounter(bytesRead);
}
return bytesRead;
}
private void incrementByteCounter(int bytesRead) throws IOException {
totalBytesRead += bytesRead;
if (totalBytesRead > maxBytes) {
throw new IOException(EXCEEDED_MAX_BYTES + ": " + maxBytes);
}
}
}