/*
* Copyright 2002-2004 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.types.selectors;
import java.io.File;
import java.util.Vector;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.AntClassLoader;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.types.Parameter;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.types.Reference;
/**
* Selector that selects files by forwarding the request on to other classes.
*
* @author <a href="mailto:bruce@callenish.com">Bruce Atherton</a>
* @since 1.5
*/
public class ExtendSelector extends BaseSelector {
private String classname = null;
private FileSelector dynselector = null;
private Vector paramVec = new Vector();
private Path classpath = null;
/**
* Default constructor.
*/
public ExtendSelector() {
}
/**
* Sets the classname of the custom selector.
*
* @param classname is the class which implements this selector
*/
public void setClassname(String classname) {
this.classname = classname;
}
/**
* Instantiates the identified custom selector class.
*/
public void selectorCreate() {
if (classname != null && classname.length() > 0) {
try {
Class c = null;
if (classpath == null) {
c = Class.forName(classname);
} else {
AntClassLoader al
= getProject().createClassLoader(classpath);
c = Class.forName(classname, true, al);
}
dynselector = (FileSelector) c.newInstance();
final Project project = getProject();
if (project != null) {
project.setProjectReference(dynselector);
}
} catch (ClassNotFoundException cnfexcept) {
setError("Selector " + classname
+ " not initialized, no such class");
} catch (InstantiationException iexcept) {
setError("Selector " + classname
+ " not initialized, could not create class");
} catch (IllegalAccessException iaexcept) {
setError("Selector " + classname
+ " not initialized, class not accessible");
}
} else {
setError("There is no classname specified");
}
}
/**
* Create new parameters to pass to custom selector.
*
* @param p The new Parameter object
*/
public void addParam(Parameter p) {
paramVec.addElement(p);
}
/**
* Set the classpath to load the classname specified using an attribute.
* @param classpath the classpath to use
*/
public final void setClasspath(Path classpath) {
if (isReference()) {
throw tooManyAttributes();
}
if (this.classpath == null) {
this.classpath = classpath;
} else {
this.classpath.append(classpath);
}
}
/**
* Specify the classpath to use to load the Selector (nested element).
* @return a classpath to be configured
*/
public final Path createClasspath() {
if (isReference()) {
throw noChildrenAllowed();
}
if (this.classpath == null) {
this.classpath = new Path(getProject());
}
return this.classpath.createPath();
}
/**
* Get the classpath
* @return the classpath
*/
public final Path getClasspath() {
return classpath;
}
/**
* Set the classpath to use for loading a custom selector by using
* a reference.
* @param r a reference to the classpath
*/
public void setClasspathref(Reference r) {
if (isReference()) {
throw tooManyAttributes();
}
createClasspath().setRefid(r);
}
/**
* These are errors specific to ExtendSelector only. If there are
* errors in the custom selector, it should throw a BuildException
* when isSelected() is called.
*/
public void verifySettings() {
// Creation is done here rather than in isSelected() because some
// containers may do a validation pass before running isSelected(),
// but we need to check for the existence of the created class.
if (dynselector == null) {
selectorCreate();
}
if (classname == null || classname.length() < 1) {
setError("The classname attribute is required");
} else if (dynselector == null) {
setError("Internal Error: The custom selector was not created");
} else if (!(dynselector instanceof ExtendFileSelector)
&& (paramVec.size() > 0)) {
setError("Cannot set parameters on custom selector that does not "
+ "implement ExtendFileSelector");
}
}
/**
* Allows the custom selector to choose whether to select a file. This
* is also where the Parameters are passed to the custom selector,
* since we know we must have them all by now. And since we must know
* both classpath and classname, creating the class is deferred to here
* as well.
*
* @exception BuildException if an error occurs
*/
public boolean isSelected(File basedir, String filename, File file)
throws BuildException {
validate();
if (paramVec.size() > 0 && dynselector instanceof ExtendFileSelector) {
Parameter[] paramArray = new Parameter[paramVec.size()];
paramVec.copyInto(paramArray);
// We know that dynselector must be non-null if no error message
((ExtendFileSelector) dynselector).setParameters(paramArray);
}
return dynselector.isSelected(basedir, filename, file);
}
}