/*
* 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.io.input;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* A Proxy stream which acts as expected, that is it passes the method
* calls on to the proxied stream and doesn't change which methods are
* being called.
* <p>
* It is an alternative base class to FilterInputStream
* to increase reusability, because FilterInputStream changes the
* methods being called, such as read(byte[]) to read(byte[], int, int).
*
* @author Stephen Colebourne
* @version $Id: ProxyInputStream.java 610010 2008-01-08 14:50:59Z niallp $
*/
public abstract class ProxyInputStream extends FilterInputStream {
/**
* Constructs a new ProxyInputStream.
*
* @param proxy the InputStream to delegate to
*/
public ProxyInputStream(InputStream proxy) {
super(proxy);
// the proxy is stored in a protected superclass variable named 'in'
}
/**
* Invokes the delegate's <code>read()</code> method.
* @return the byte read or -1 if the end of stream
* @throws IOException if an I/O error occurs
*/
public int read() throws IOException {
return in.read();
}
/**
* Invokes the delegate's <code>read(byte[])</code> method.
* @param bts the buffer to read the bytes into
* @return the number of bytes read or -1 if the end of stream
* @throws IOException if an I/O error occurs
*/
public int read(byte[] bts) throws IOException {
return in.read(bts);
}
/**
* Invokes the delegate's <code>read(byte[], int, int)</code> method.
* @param bts the buffer to read the bytes into
* @param st The start offset
* @param end The number of bytes to read
* @return the number of bytes read or -1 if the end of stream
* @throws IOException if an I/O error occurs
*/
public int read(byte[] bts, int st, int end) throws IOException {
return in.read(bts, st, end);
}
/**
* Invokes the delegate's <code>skip(long)</code> method.
* @param ln the number of bytes to skip
* @return the number of bytes to skipped or -1 if the end of stream
* @throws IOException if an I/O error occurs
*/
public long skip(long ln) throws IOException {
return in.skip(ln);
}
/**
* Invokes the delegate's <code>available()</code> method.
* @return the number of available bytes
* @throws IOException if an I/O error occurs
*/
public int available() throws IOException {
return in.available();
}
/**
* Invokes the delegate's <code>close()</code> method.
* @throws IOException if an I/O error occurs
*/
public void close() throws IOException {
in.close();
}
/**
* Invokes the delegate's <code>mark(int)</code> method.
* @param idx read ahead limit
*/
public synchronized void mark(int idx) {
in.mark(idx);
}
/**
* Invokes the delegate's <code>reset()</code> method.
* @throws IOException if an I/O error occurs
*/
public synchronized void reset() throws IOException {
in.reset();
}
/**
* Invokes the delegate's <code>markSupported()</code> method.
* @return true if mark is supported, otherwise false
*/
public boolean markSupported() {
return in.markSupported();
}
}