/**************************************************************** | |
* 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"); | |
} | |
} |