/*
* 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.tools.ant.util.regexp;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.util.JavaEnvUtils;
/***
* Regular expression factory, which will create Regexp objects. The
* actual implementation class depends on the System or Ant Property:
* <code>ant.regexp.regexpimpl</code>.
*
*/
public class RegexpFactory extends RegexpMatcherFactory {
/** Constructor for RegexpFactory */
public RegexpFactory() {
}
/***
* Create a new regular expression matcher instance.
* @return the matcher instance
* @throws BuildException on error
*/
public Regexp newRegexp() throws BuildException {
return (Regexp) newRegexp(null);
}
/***
* Create a new regular expression matcher instance.
*
* @param p Project whose ant.regexp.regexpimpl property will be used.
* @return the matcher instance
* @throws BuildException on error
*/
public Regexp newRegexp(Project p) throws BuildException {
String systemDefault = null;
if (p == null) {
systemDefault = System.getProperty("ant.regexp.regexpimpl");
} else {
systemDefault = p.getProperty("ant.regexp.regexpimpl");
}
if (systemDefault != null) {
return createRegexpInstance(systemDefault);
// XXX should we silently catch possible exceptions and try to
// load a different implementation?
}
Throwable cause = null;
try {
testAvailability("java.util.regex.Matcher");
return createRegexpInstance("org.apache.tools.ant.util.regexp.Jdk14RegexpRegexp");
} catch (BuildException be) {
cause = orCause(cause, be, JavaEnvUtils.getJavaVersionNumber() < 14);
}
try {
testAvailability("org.apache.oro.text.regex.Pattern");
return createRegexpInstance("org.apache.tools.ant.util.regexp.JakartaOroRegexp");
} catch (BuildException be) {
cause = orCause(cause, be, true);
}
try {
testAvailability("org.apache.regexp.RE");
return createRegexpInstance("org.apache.tools.ant.util.regexp.JakartaRegexpRegexp");
} catch (BuildException be) {
cause = orCause(cause, be, true);
}
throw new BuildException(
"No supported regular expression matcher found"
+ (cause != null ? ": " + cause : ""), cause);
}
/**
* Wrapper over RegexpMatcherFactory.createInstance that ensures that
* we are dealing with a Regexp implementation.
* @param classname the name of the class to use.
* @return the instance.
* @throws BuildException if there is a problem.
* @since 1.3
*
* @see RegexpMatcherFactory#createInstance(String)
*/
protected Regexp createRegexpInstance(String classname)
throws BuildException {
RegexpMatcher m = createInstance(classname);
if (m instanceof Regexp) {
return (Regexp) m;
} else {
throw new BuildException(classname + " doesn't implement the Regexp interface");
}
}
}
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