org.apache.wicket.util.upload.LimitedInputStream Maven / Gradle / Ivy
Show all versions of org.ops4j.pax.wicket.service Show documentation
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses 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 org.apache.wicket.util.upload;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* An input stream, which limits its data size. This stream is used, if the content length is
* unknown.
*/
public abstract class LimitedInputStream extends FilterInputStream implements Closeable
{
/**
* The maximum size of an item, in bytes.
*/
private final long sizeMax;
/**
* The current number of bytes.
*/
private long count;
/**
* Whether this stream is already closed.
*/
private boolean closed;
/**
* Creates a new instance.
*
* @param pIn
* The input stream, which shall be limited.
* @param pSizeMax
* The limit; no more than this number of bytes shall be returned by the source
* stream.
*/
public LimitedInputStream(InputStream pIn, long pSizeMax)
{
super(pIn);
sizeMax = pSizeMax;
}
/**
* Called to indicate, that the input streams limit has been exceeded.
*
* @param pSizeMax
* The input streams limit, in bytes.
* @param pCount
* The actual number of bytes.
* @throws IOException
* The called method is expected to raise an IOException.
*/
protected abstract void raiseError(long pSizeMax, long pCount) throws IOException;
/**
* Called to check, whether the input streams limit is reached.
*
* @throws IOException
* The given limit is exceeded.
*/
private void checkLimit() throws IOException
{
if (count > sizeMax)
{
raiseError(sizeMax, count);
}
}
/**
* Reads the next byte of data from this input stream. The value byte is returned as an
* int in the range 0 to 255. If no byte is available
* because the end of the stream has been reached, the value -1 is returned. This
* method blocks until input data is available, the end of the stream is detected, or an
* exception is thrown.
*
* This method simply performs in.read() and returns the result.
*
* @return the next byte of data, or -1 if the end of the stream is reached.
* @exception IOException
* if an I/O error occurs.
* @see java.io.FilterInputStream#in
*/
@Override
public int read() throws IOException
{
int res = super.read();
if (res != -1)
{
count++;
checkLimit();
}
return res;
}
/**
* Reads up to len bytes of data from this input stream into an array of bytes. If
* len is not zero, the method blocks until some input is available; otherwise, no
* bytes are read and 0 is returned.
*
* This method simply performs in.read(b, off, len) and returns the result.
*
* @param b
* the buffer into which the data is read.
* @param off
* The start offset in the destination array b.
* @param len
* the maximum number of bytes read.
* @return the total number of bytes read into the buffer, or -1 if there is no
* more data because the end of the stream has been reached.
* @exception NullPointerException
* If b is null.
* @exception IndexOutOfBoundsException
* If off is negative, len is negative, or
* len is greater than b.length - off
* @exception IOException
* if an I/O error occurs.
* @see java.io.FilterInputStream#in
*/
@Override
public int read(byte[] b, int off, int len) throws IOException
{
int res = super.read(b, off, len);
if (res > 0)
{
count += res;
checkLimit();
}
return res;
}
/**
* Returns, whether this stream is already closed.
*
* @return True, if the stream is closed, otherwise false.
* @throws IOException
* An I/O error occurred.
*/
public boolean isClosed() throws IOException
{
return closed;
}
/**
* Closes this input stream and releases any system resources associated with the stream. This
* method simply performs in.close().
*
* @exception IOException
* if an I/O error occurs.
* @see java.io.FilterInputStream#in
*/
@Override
public void close() throws IOException
{
closed = true;
super.close();
}
}