- /*
- * $Header: /home/cvs/jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/AutoCloseInputStream.java,v 1.9 2004/04/18 23:51:34 jsdever Exp $
- * $Revision: 1.9 $
- * $Date: 2004/04/18 23:51:34 $
- *
- * ====================================================================
- *
- * Copyright 2002-2004 The Apache Software Foundation
- *
- * 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.
- * ====================================================================
- *
- * This software consists of voluntary contributions made by many
- * individuals on behalf of the Apache Software Foundation. For more
- * information on the Apache Software Foundation, please see
- * <http://www.apache.org/>.
- *
- */
-
- package org.apache.commons.httpclient;
-
- import java.io.FilterInputStream;
- import java.io.IOException;
- import java.io.InputStream;
-
- /**
- * Closes an underlying stream as soon as the end of the stream is reached, and
- * notifies a client when it has done so.
- *
- * @author Ortwin Glück
- * @author Eric Johnson
- * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
- *
- * @since 2.0
- */
- class AutoCloseInputStream extends FilterInputStream {
-
- /**
- * True if this stream is open. Assume that the underlying stream
- * is open until we get an EOF indication.
- */
- private boolean streamOpen = true;
-
- /** True if the stream closed itself. */
- private boolean selfClosed = false;
-
- /**
- * The watcher is notified when the contents of the stream have
- * been exhausted
- */
- private ResponseConsumedWatcher watcher = null;
-
- /**
- * Create a new auto closing stream for the provided connection
- *
- * @param in the input stream to read from
- * @param watcher To be notified when the contents of the stream have been
- * consumed.
- */
- public AutoCloseInputStream(
- final InputStream in, final ResponseConsumedWatcher watcher) {
- super(in);
- this.watcher = watcher;
- }
-
- /**
- * Reads the next byte of data from the input stream.
- *
- * @throws IOException when there is an error reading
- * @return the character read, or -1 for EOF
- */
- public int read() throws IOException {
- int l = -1;
-
- if (isReadAllowed()) {
- // underlying stream not closed, go ahead and read.
- l = super.read();
- checkClose(l);
- }
-
- return l;
- }
-
- /**
- * Reads up to <code>len</code> bytes of data from the stream.
- *
- * @param b a <code>byte</code> array to read data into
- * @param off an offset within the array to store data
- * @param len the maximum number of bytes to read
- * @return the number of bytes read or -1 for EOF
- * @throws IOException if there are errors reading
- */
- public int read(byte[] b, int off, int len) throws IOException {
- int l = -1;
-
- if (isReadAllowed()) {
- l = super.read(b, off, len);
- checkClose(l);
- }
-
- return l;
- }
-
- /**
- * Reads some number of bytes from the input stream and stores them into the
- * buffer array b.
- *
- * @param b a <code>byte</code> array to read data into
- * @return the number of bytes read or -1 for EOF
- * @throws IOException if there are errors reading
- */
- public int read(byte[] b) throws IOException {
- int l = -1;
-
- if (isReadAllowed()) {
- l = super.read(b);
- checkClose(l);
- }
- return l;
- }
-
- /**
- * Close the stream, and also close the underlying stream if it is not
- * already closed.
- * @throws IOException If an IO problem occurs.
- */
- public void close() throws IOException {
- if (!selfClosed) {
- selfClosed = true;
- notifyWatcher();
- }
- }
-
- /**
- * Close the underlying stream should the end of the stream arrive.
- *
- * @param readResult The result of the read operation to check.
- * @throws IOException If an IO problem occurs.
- */
- private void checkClose(int readResult) throws IOException {
- if (readResult == -1) {
- notifyWatcher();
- }
- }
-
- /**
- * See whether a read of the underlying stream should be allowed, and if
- * not, check to see whether our stream has already been closed!
- *
- * @return <code>true</code> if it is still OK to read from the stream.
- * @throws IOException If an IO problem occurs.
- */
- private boolean isReadAllowed() throws IOException {
- if (!streamOpen && selfClosed) {
- throw new IOException("Attempted read on closed stream.");
- }
- return streamOpen;
- }
-
- /**
- * Notify the watcher that the contents have been consumed.
- * @throws IOException If an IO problem occurs.
- */
- private void notifyWatcher() throws IOException {
- if (streamOpen) {
- super.close();
- streamOpen = false;
-
- if (watcher != null) {
- watcher.responseConsumed();
- }
- }
- }
- }
-