2 * Sonitus - ExternalFilter.java - Copyright © 2013 David Roden
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 package net.pterodactylus.sonitus.data.filter;
20 import java.io.IOException;
21 import java.io.InputStream;
22 import java.io.OutputStream;
23 import java.util.logging.Logger;
25 import net.pterodactylus.sonitus.data.AbstractFilter;
26 import net.pterodactylus.sonitus.data.Filter;
27 import net.pterodactylus.sonitus.data.Metadata;
28 import net.pterodactylus.sonitus.io.InputStreamDrainer;
30 import com.google.common.collect.ImmutableList;
31 import com.google.common.collect.Iterables;
34 * {@link net.pterodactylus.sonitus.data.Filter} implementation that runs its
35 * {@link net.pterodactylus.sonitus.data.Source} through an external program.
37 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
39 public abstract class ExternalFilter extends AbstractFilter implements Filter {
42 private final Logger logger = Logger.getLogger(getClass().getName());
44 /** The external process. */
45 private Process process;
48 * Creates a new external filter with the given name.
51 * The name of the filter
53 protected ExternalFilter(String name) {
62 public void open(Metadata metadata) throws IOException {
63 process = Runtime.getRuntime().exec(Iterables.toArray(ImmutableList.<String>builder().add(binary(metadata)).addAll(parameters(metadata)).build(), String.class));
64 InputStream processError = process.getErrorStream();
65 new Thread(new InputStreamDrainer(processError)).start();
75 protected InputStream createInputStream() throws IOException {
76 return process.getInputStream();
80 protected OutputStream createOutputStream() throws IOException {
81 return process.getOutputStream();
89 * Returns the location of the binary to execute.
92 * The metadata being processed
93 * @return The location of the binary to execute
95 protected abstract String binary(Metadata metadata);
98 * Returns the parameters for the binary.
101 * The metadata being processed
102 * @return The parameters for the binary
104 protected abstract Iterable<String> parameters(Metadata metadata);