JavaClassObject.java

package org.javabuilders.swing.plugin.glazedlists.compiler;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URI;

import javax.tools.SimpleJavaFileObject;

/**
 * Taken from: http://www.javablogging.com/dynamic-in-memory-compilation/
 */
public class JavaClassObject extends SimpleJavaFileObject {

	/**
	 * Byte code created by the compiler will be stored in this
	 * ByteArrayOutputStream so that we can later get the byte array out of it
	 * and put it in the memory as an instance of our class.
	 */
	protected final ByteArrayOutputStream bos = new ByteArrayOutputStream();

	/**
	 * Registers the compiled class object under URI containing the class full
	 * name
	 * 
	 * @param name
	 *            Full name of the compiled class
	 * @param kind
	 *            Kind of the data. It will be CLASS in our case
	 */
	public JavaClassObject(String name, Kind kind) {
		super(URI.create("string:///" + name.replace('.', '/') + kind.extension), kind);
	}

	/**
	 * Will be used by our file manager to get the byte code that can be put
	 * into memory to instantiate our class
	 * 
	 * @return compiled byte code
	 */
	public byte[] getBytes() {
		return bos.toByteArray();
	}

	/**
	 * Will provide the compiler with an output stream that leads to our byte
	 * array. This way the compiler will write everything into the byte array
	 * that we will instantiate later
	 */
	@Override
	public OutputStream openOutputStream() throws IOException {
		return bos;
	}
}