package com.sun.istack.tools;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DynamicConfigurator;
import org.apache.tools.ant.IntrospectionHelper;
import org.apache.tools.ant.Task;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Iterator;
import java.util.Map.Entry;
/**
* Executes a {@link Task} in a special class loader that allows
* us to control where to load 2.1 APIs, even if we run in Java 6.
*
* <p>
* No JDK 1.5 code here, please. This allows us to detect "require JDK5" bug nicely.
*
* @author Kohsuke Kawaguchi
* @author Bhakti Mehta
*/
public abstract class ProtectedTask extends Task implements DynamicConfigurator {
private final AntElement root = new AntElement("root");
public void setDynamicAttribute(String name, String value) throws BuildException {
root.setDynamicAttribute(name,value);
}
public Object createDynamicElement(String name) throws BuildException {
return root.createDynamicElement(name);
}
public void execute() throws BuildException {
//Leave XJC2 in the publicly visible place
// and then isolate XJC1 in a child class loader,
// then use a MaskingClassLoader
// so that the XJC2 classes in the parent class loader
// won't interfere with loading XJC1 classes in a child class loader
ClassLoader ccl = Thread.currentThread().getContextClassLoader();
try {
ClassLoader cl = createClassLoader();
Class driver = cl.loadClass(getCoreClassName());
Task t = (Task)driver.newInstance();
t.setProject(getProject());
t.setTaskName(getTaskName());
root.configure(t);
Thread.currentThread().setContextClassLoader(cl);
t.execute();
} catch (UnsupportedClassVersionError e) {
throw new BuildException("Requires JDK 5.0 or later. Please download it from http://java.sun.com/j2se/1.5/");
} catch (ClassNotFoundException e) {
throw new BuildException(e);
} catch (InstantiationException e) {
throw new BuildException(e);
} catch (IllegalAccessException e) {
throw new BuildException(e);
} catch (IOException e) {
throw new BuildException(e);
} finally {
Thread.currentThread().setContextClassLoader(ccl);
}
}
/**
* Returns the name of the class that extends {@link Task}.
* This class will be loaded int the protected classloader.
*/
protected abstract String getCoreClassName();
/**
* Creates a protective class loader that will host the actual task.
*/
protected abstract ClassLoader createClassLoader() throws ClassNotFoundException, IOException;
/**
* Captures the elements and attributes.
*/
private class AntElement implements DynamicConfigurator {
private final String name;
private final Map/*<String,String>*/ attributes = new HashMap();
private final List/*<AntElement>*/ elements = new ArrayList();
public AntElement(String name) {
this.name = name;
}
public void setDynamicAttribute(String name, String value) throws BuildException {
attributes.put(name,value);
}
public Object createDynamicElement(String name) throws BuildException {
AntElement e = new AntElement(name);
elements.add(e);
return e;
}
/**
* Copies the properties into the Ant task.
*/
public void configure(Object antObject) {
IntrospectionHelper ih = IntrospectionHelper.getHelper(antObject.getClass());
// set attributes first
for (Iterator itr = attributes.entrySet().iterator(); itr.hasNext();) {
Entry att = (Entry)itr.next();
ih.setAttribute(getProject(), antObject, (String)att.getKey(), (String)att.getValue());
}
// then nested elements
for (Iterator itr = elements.iterator(); itr.hasNext();) {
AntElement e = (AntElement) itr.next();
Object child = ih.createElement(getProject(), antObject, e.name);
e.configure(child);
ih.storeElement(getProject(), antObject, child, e.name);
}
}
}
}