/*******************************************************************************
* Copyright (c) 2009 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.wst.jsdt.core.util;
import java.io.IOException;
import java.io.Reader;
/**
* Provides the contents of multiple Readers in sequence.
*/
public class SequenceReader extends Reader {
private Reader[] fReaders;
private Reader fCurrentReader;
/**
* @param readers
* the readers from which to read
*/
public SequenceReader(Reader[] readers) {
fReaders = readers;
if (fReaders.length > 0) {
fCurrentReader = fReaders[0];
}
}
/*
* (non-Javadoc)
*
* @see java.io.Reader#close()
*/
public void close() throws IOException {
if (fCurrentReader != null) {
for (int i = 0; i <= indexOf(fCurrentReader); i++) {
fReaders[i].close();
}
}
}
private int indexOf(Reader r) {
for (int i = 0; i < fReaders.length; i++) {
if (fReaders[i] == r) {
return i;
}
}
return -1;
}
/*
* (non-Javadoc)
*
* @see java.io.Reader#read(char[], int, int)
*/
public int read(char[] cbuf, int off, int len) throws IOException {
if (fCurrentReader != null) {
int bufIndex = off;
int read = 0;
for (bufIndex = off; bufIndex - off < len; bufIndex++) {
int c = primRead();
if (c != -1) {
read++;
cbuf[bufIndex] = (char) c;
}
else if (read == 0) {
return -1;
}
}
return read;
}
return -1;
}
/**
* @return
*/
private int primRead() {
int c = -1;
try {
c = fCurrentReader.read();
}
catch (IOException e) {
}
if (c == -1) {
int index = indexOf(fCurrentReader);
if (index > -1 && index < fReaders.length - 1) {
fCurrentReader = fReaders[index + 1];
c = primRead();
}
}
return c;
}
}