| /* |
| * 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.commons.fileupload.util; |
| |
| 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 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 <code>int</code> in the range |
| * <code>0</code> to <code>255</code>. If no byte is available |
| * because the end of the stream has been reached, the value |
| * <code>-1</code> is returned. This method blocks until input data |
| * is available, the end of the stream is detected, or an exception |
| * is thrown. |
| * <p> |
| * This method |
| * simply performs <code>in.read()</code> and returns the result. |
| * |
| * @return the next byte of data, or <code>-1</code> if the end of the |
| * stream is reached. |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public int read() throws IOException { |
| int res = super.read(); |
| if (res != -1) { |
| count++; |
| checkLimit(); |
| } |
| return res; |
| } |
| |
| /** |
| * Reads up to <code>len</code> bytes of data from this input stream |
| * into an array of bytes. If <code>len</code> is not zero, the method |
| * blocks until some input is available; otherwise, no |
| * bytes are read and <code>0</code> is returned. |
| * <p> |
| * This method simply performs <code>in.read(b, off, len)</code> |
| * and returns the result. |
| * |
| * @param b the buffer into which the data is read. |
| * @param off The start offset in the destination array |
| * <code>b</code>. |
| * @param len the maximum number of bytes read. |
| * @return the total number of bytes read into the buffer, or |
| * <code>-1</code> if there is no more data because the end of |
| * the stream has been reached. |
| * @exception NullPointerException If <code>b</code> is <code>null</code>. |
| * @exception IndexOutOfBoundsException If <code>off</code> is negative, |
| * <code>len</code> is negative, or <code>len</code> is greater than |
| * <code>b.length - off</code> |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| 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 <code>in.close()</code>. |
| * |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public void close() throws IOException { |
| closed = true; |
| super.close(); |
| } |
| } |