| /**************************************************************** |
| * 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.james.mime4j; |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| |
| /** |
| * InputStream that shields its underlying input stream from |
| * being closed. |
| * |
| * |
| * @version $Id: CloseShieldInputStream.java,v 1.2 2004/10/02 12:41:10 ntherning Exp $ |
| */ |
| public class CloseShieldInputStream extends InputStream { |
| |
| /** |
| * Underlying InputStream |
| */ |
| private InputStream is; |
| |
| public CloseShieldInputStream(InputStream is) { |
| this.is = is; |
| } |
| |
| public InputStream getUnderlyingStream() { |
| return is; |
| } |
| |
| /** |
| * @see java.io.InputStream#read() |
| */ |
| public int read() throws IOException { |
| checkIfClosed(); |
| return is.read(); |
| } |
| |
| /** |
| * @see java.io.InputStream#available() |
| */ |
| public int available() throws IOException { |
| checkIfClosed(); |
| return is.available(); |
| } |
| |
| |
| /** |
| * Set the underlying InputStream to null |
| */ |
| public void close() throws IOException { |
| is = null; |
| } |
| |
| /** |
| * @see java.io.FilterInputStream#reset() |
| */ |
| public synchronized void reset() throws IOException { |
| checkIfClosed(); |
| is.reset(); |
| } |
| |
| /** |
| * @see java.io.FilterInputStream#markSupported() |
| */ |
| public boolean markSupported() { |
| if (is == null) |
| return false; |
| return is.markSupported(); |
| } |
| |
| /** |
| * @see java.io.FilterInputStream#mark(int) |
| */ |
| public synchronized void mark(int readlimit) { |
| if (is != null) |
| is.mark(readlimit); |
| } |
| |
| /** |
| * @see java.io.FilterInputStream#skip(long) |
| */ |
| public long skip(long n) throws IOException { |
| checkIfClosed(); |
| return is.skip(n); |
| } |
| |
| /** |
| * @see java.io.FilterInputStream#read(byte[]) |
| */ |
| public int read(byte b[]) throws IOException { |
| checkIfClosed(); |
| return is.read(b); |
| } |
| |
| /** |
| * @see java.io.FilterInputStream#read(byte[], int, int) |
| */ |
| public int read(byte b[], int off, int len) throws IOException { |
| checkIfClosed(); |
| return is.read(b, off, len); |
| } |
| |
| /** |
| * Check if the underlying InputStream is null. If so throw an Exception |
| * |
| * @throws IOException if the underlying InputStream is null |
| */ |
| private void checkIfClosed() throws IOException { |
| if (is == null) |
| throw new IOException("Stream is closed"); |
| } |
| } |