Using the loan pattern in Java

	In Java you often deal with a lot of boilerplate code. A typical example is
	opening an inputstream, using the inputstream and next closing it. But this
	simple use case takes writing quite a bit of code.Some of this boilerplate
	can be factored out by using the loan pattern, where the bank connects a
	producer and consumer and takes care of the heavy lifting. This code can be
	further generalized using generics but for illustrating purposes it serves
	as a nice example.
	**************************************************
	Consumer Interface *
	**************************************************
	public interface InputStreamConsumer {
	void consume(InputStream in) throws Exception;
	}
	**************************************************
	Producer Interface *
	**************************************************
	public interface InputStreamProducer {
	InputStream produce() throws Exception;
	}
	**************************************************
	Lender which connects producer and consumer *
	**************************************************
	public class InputStreamLender {
	public static void lend(InputStreamProducer producer, InputStreamConsumer consumer)
	throws Exception {
	InputStream in = null;
	try {
	in = producer.produce();
	consumer.consume(in);
	} finally {
	if (in != null) {
	in.close();
	}
	}
	}
	}
	**************************************************
	Util class providing implementation for *
	a InputstreamProvider *
	**************************************************
	public class InputStreamUtils {
	public static InputStreamProducer fromClassPath(final String path) {
	return new InputStreamProducer() {
	@Override
	public InputStream produce() throws Exception {
	return InputStreamUtils.class.getClassLoader().getResourceAsStream(path);
	}
	};
	}
	}
	**************************************************
	Small test class testing we get indeed an *
	inputstream to work with *
	**************************************************
	public class InputStreamLenderTest {
	@Test
	public void testInputStreamLender() throws Exception {
	InputStreamLender.lend(
	InputStreamUtils.fromClassPath("test.properties"),
	new InputStreamConsumer() {
	@Override
	public void consume(InputStream in) throws Exception {
	Assert.assertNotNull(in);
	}
	});
	}
	}
	**************************************************
	A class using our newly developed loan pattern *
	**************************************************
	public class PropertyLoader {
	public static Properties loadFromClassPath(String path) throws Exception{
	final Properties props = new Properties();
	InputStreamLender.lend(
	InputStreamUtils.fromClassPath(path),
	new InputStreamConsumer() {
	@Override
	public void consume(InputStream in) throws Exception {
	props.load(in);
	}
	});
	return props;
	}
	}
	**************************************************

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