Load a properties file using Guava.

ReadPropertiesWithGuava.java

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Properties;

import com.google.common.io.ByteSource;
import com.google.common.io.Resources;

/**
 * Reads a properties file and print all the key value pairs to the console.
 * Note: Writing to console is just for convenience here.
 */
public final class ReadPropertiesWithGuava {

	public final static void main(final String[] args) {
		final URL url = Resources.getResource("spring-config.properties");
		final ByteSource byteSource = Resources.asByteSource(url);
		final Properties properties = new Properties();
		InputStream inputStream = null;
		try {
			inputStream = byteSource.openBufferedStream();
			properties.load(inputStream);
			properties.list(System.out);
		} catch (final IOException ioException) {
			ioException.printStackTrace();
		} finally {
			if (inputStream != null) {
				try {
					inputStream.close();
				} catch (final IOException ioException) {
					ioException.printStackTrace();
				}
			}
		}
	}
}

with java 7+, you can simplify your code to:

public void loadProperties(String filename) {
    URL url = Resources.getResource(filename);

    final ByteSource byteSource = Resources.asByteSource(url);
    try (InputStream inputStream = byteSource.openBufferedStream()) {
        props.load(inputStream);
        props.list(System.out);
    } catch (IOException e) {
        LOGGER.error("openBufferedStream failed!", e);
    }
}

You can significantly improve the performance of loading Properties by making Properties write to something else instead of itself.

Properties properties = new Properties() {
		final Map<String, String> ordered = new LinkedHashMap<String, String>();
		// Hack to use properties class to load but our map for preserved order
		@SuppressWarnings("serial")
		Properties bp = new Properties() {
			@Override
			public Object put(
					Object key,
					Object value) {
				return ordered.put((String) key, (String) value);
				// return super.put(key, value);
			}
		};
}

The reason it is faster is because Properties is a HashTable which has all puts synchronized.