org.apache.tools.ant.filters.StripLineBreaks Maven / Gradle / Ivy
/*
* 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
*
* https://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 org.apache.tools.ant.types.Parameter;
/**
* Filter to flatten the stream to a single line.
*
* Example:
*
* <striplinebreaks/>
*
* Or:
*
* <filterreader
* classname="org.apache.tools.ant.filters.StripLineBreaks"/>
*
*/
public final class StripLineBreaks
extends BaseParamFilterReader
implements ChainableReader {
/**
* Line-breaking characters.
* What should we do on funny IBM mainframes with odd line endings?
*/
private static final String DEFAULT_LINE_BREAKS = "\r\n";
/** Parameter name for the line-breaking characters parameter. */
private static final String LINE_BREAKS_KEY = "linebreaks";
/** The characters that are recognized as line breaks. */
private String lineBreaks = DEFAULT_LINE_BREAKS;
/**
* Constructor for "dummy" instances.
*
* @see BaseFilterReader#BaseFilterReader()
*/
public StripLineBreaks() {
super();
}
/**
* Creates a new filtered reader.
*
* @param in A Reader object providing the underlying stream.
* Must not be null.
*/
public StripLineBreaks(final Reader in) {
super(in);
}
/**
* Returns the next character in the filtered stream, only including
* characters not in the set of line-breaking characters.
*
* @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 {
if (!getInitialized()) {
initialize();
setInitialized(true);
}
int ch = in.read();
while (ch != -1) {
if (lineBreaks.indexOf(ch) == -1) {
break;
} else {
ch = in.read();
}
}
return ch;
}
/**
* Sets the line-breaking characters.
*
* @param lineBreaks A String containing all the characters to be
* considered as line-breaking.
*/
public void setLineBreaks(final String lineBreaks) {
this.lineBreaks = lineBreaks;
}
/**
* Returns the line-breaking characters as a String.
*
* @return a String containing all the characters considered as
* line-breaking
*/
private String getLineBreaks() {
return lineBreaks;
}
/**
* Creates a new StripLineBreaks 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) {
StripLineBreaks newFilter = new StripLineBreaks(rdr);
newFilter.setLineBreaks(getLineBreaks());
newFilter.setInitialized(true);
return newFilter;
}
/**
* Parses the parameters to set the line-breaking characters.
*/
private void initialize() {
String userDefinedLineBreaks = null;
Parameter[] params = getParameters();
if (params != null) {
for (Parameter param : params) {
if (LINE_BREAKS_KEY.equals(param.getName())) {
userDefinedLineBreaks = param.getValue();
break;
}
}
}
if (userDefinedLineBreaks != null) {
lineBreaks = userDefinedLineBreaks;
}
}
}