/* * Copyright 2003-2004 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. * */ package org.apache.tools.ant.filters; import java.io.IOException; import java.io.Reader; import java.io.File; import java.io.BufferedReader; import java.io.FileReader; import org.apache.tools.ant.types.Parameter; /** * Concats a file before and/or after the file. * *
Example:
** Copies all java sources from src to build and adds the * content of apache-license-java.txt add the beginning of each * file. * * @since 1.6 * @version 2003-09-23 */ public final class ConcatFilter extends BaseParamFilterReader implements ChainableReader { /** File to add before the content. */ private File prepend; /** File to add after the content. */ private File append; /** Reader for prepend-file. */ private Reader prependReader = null; /** Reader for append-file. */ private Reader appendReader = null; /** * Constructor for "dummy" instances. * * @see BaseFilterReader#BaseFilterReader() */ public ConcatFilter() { super(); } /** * Creates a new filtered reader. * * @param in A Reader object providing the underlying stream. * Must not be* ** * **
null
.
*/
public ConcatFilter(final Reader in) {
super(in);
}
/**
* Returns the next character in the filtered stream. If the desired
* number of lines have already been read, the resulting stream is
* effectively at an end. Otherwise, the next character from the
* underlying stream is read and returned.
*
* @return the next character in the resulting stream, or -1
* if the end of the resulting stream has been reached
*
* @exception IOException if the underlying stream throws an IOException
* during reading
*/
public int read() throws IOException {
// do the "singleton" initialization
if (!getInitialized()) {
initialize();
setInitialized(true);
}
int ch = -1;
// The readers return -1 if they end. So simply read the "prepend"
// after that the "content" and at the end the "append" file.
if (prependReader != null) {
ch = prependReader.read();
if (ch == -1) {
// I am the only one so I have to close the reader
prependReader.close();
prependReader = null;
}
}
if (ch == -1) {
ch = super.read();
}
if (ch == -1) {
// don't call super.close() because that reader is used
// on other places ...
if (appendReader != null) {
ch = appendReader.read();
if (ch == -1) {
// I am the only one so I have to close the reader
appendReader.close();
appendReader = null;
}
}
}
return ch;
}
/**
* Sets prepend attribute.
* @param prepend new value
*/
public void setPrepend(final File prepend) {
this.prepend = prepend;
}
/**
* Returns prepend attribute.
* @return prepend attribute
*/
public File getPrepend() {
return prepend;
}
/**
* Sets append attribute.
* @param append new value
*/
public void setAppend(final File append) {
this.append = append;
}
/**
* Returns append attribute.
* @return append attribute
*/
public File getAppend() {
return append;
}
/**
* Creates a new ConcatReader using the passed in
* Reader for instantiation.
*
* @param rdr A Reader object providing the underlying stream.
* Must not be null
.
*
* @return a new filter based on this configuration, but filtering
* the specified reader
*/
public Reader chain(final Reader rdr) {
ConcatFilter newFilter = new ConcatFilter(rdr);
newFilter.setPrepend(getPrepend());
newFilter.setAppend(getAppend());
// Usually the initialized is set to true. But here it must not.
// Because the prepend and append readers have to be instantiated
// on runtime
//newFilter.setInitialized(true);
return newFilter;
}
/**
* Scans the parameters list for the "lines" parameter and uses
* it to set the number of lines to be returned in the filtered stream.
* also scan for skip parameter.
*/
private void initialize() throws IOException {
// get parameters
Parameter[] params = getParameters();
if (params != null) {
for (int i = 0; i < params.length; i++) {
if ("prepend".equals(params[i].getName())) {
setPrepend(new File(params[i].getValue()));
continue;
}
if ("append".equals(params[i].getName())) {
setAppend(new File(params[i].getValue()));
continue;
}
}
}
if (prepend != null) {
if (!prepend.isAbsolute()) {
prepend = new File(getProject().getBaseDir(), prepend.getPath());
}
prependReader = new BufferedReader(new FileReader(prepend));
}
if (append != null) {
if (!append.isAbsolute()) {
append = new File(getProject().getBaseDir(), append.getPath());
}
appendReader = new BufferedReader(new FileReader(append));
}
}
}