SqlAsset.java

public class SqlAsset implements Asset {

	private final InputStream stream;

	private SqlAsset(InputStream stream) {
		this.stream = Objects.requireNonNull(stream);
	}

	public static Asset parse(String ... filenames) {
		InputStream[] streams = new InputStream[filenames.length];
		ClassLoader loader = SqlAsset.class.getClassLoader();
		for (int i = 0; i < filenames.length; i++) {
			streams[i] = loader.getResourceAsStream(filenames[i]);
		}
		return parse(streams);
	}

	public static Asset parse(InputStream ... streams) {
		final StringBuffer buffer = new StringBuffer();
		boolean waitForDoubleDollars = false;
		for (InputStream stream : streams) {
			Objects.requireNonNull(stream);
			try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream, Charsets.UTF_8))) {
				String line;
				while ((line = reader.readLine()) != null) {
					line = StringUtils.trimToNull(line);
					if (line == null || line.startsWith("--")) {
						continue;
					} else if (!waitForDoubleDollars && line.endsWith("$$")) {
						waitForDoubleDollars = true;
						buffer.append(line).append(' ');
					} else if (waitForDoubleDollars && line.startsWith("$$")) {
						waitForDoubleDollars = false;
						buffer.append(line).append(line.endsWith(";") ? '\n' : ' ');
					} else if (!waitForDoubleDollars && line.endsWith(";")) {
						buffer.append(line).append('\n');
					} else {
						buffer.append(line).append(' ');
					}
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		String sql = buffer.toString();
		return new SqlAsset(new ByteArrayInputStream(sql.getBytes(Charsets.UTF_8)));
	}

	@Override
	public InputStream openStream() {
		return stream;
	}

}

Using apache commons-lang and commons-codec for this.