remove old temp files

pdb-ui/src/main/java/org/lucares/pdbui/CleanupThread.java

@@ -0,0 +1,95 @@
+package org.lucares.pdbui;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.attribute.FileTime;
+import java.time.Instant;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.DisposableBean;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.scheduling.concurrent.CustomizableThreadFactory;
+import org.springframework.stereotype.Component;
+
+@Component
+public class CleanupThread implements DisposableBean, PropertyKeys {
+
+	private static final Logger LOGGER = LoggerFactory.getLogger(CleanupThread.class);
+
+	private static final class RemoveTempFiles implements Runnable {
+
+		private final Path outputPath;
+		private final int cacheDurationInSeconds;
+
+		public RemoveTempFiles(final Path outputPath, final int cacheDurationInSeconds) {
+			this.outputPath = outputPath;
+			this.cacheDurationInSeconds = cacheDurationInSeconds;
+		}
+
+		@Override
+		public void run() {
+
+			try {
+				Files.walk(outputPath)//
+						.filter(Files::isRegularFile)//
+						.filter(this::isStale)//
+						.forEach(RemoveTempFiles::delete);
+			} catch (final IOException | RuntimeException e) {
+				LOGGER.warn("failed to walk " + outputPath + ". Cannot delete stale files", e);
+			}
+		}
+
+		private static void delete(final Path path) {
+			try {
+				LOGGER.debug("deleting stale file: " + path);
+				Files.delete(path);
+			} catch (final IOException e) {
+				LOGGER.warn("failed to delete stale file " + path, e);
+			}
+		}
+
+		private boolean isStale(final Path path) {
+			final Instant maxAge = Instant.now().minusSeconds(cacheDurationInSeconds);
+			try {
+				final FileTime lastModifiedTime = Files.getLastModifiedTime(path);
+				final Instant lastModifiedInstant = lastModifiedTime.toInstant();
+				return lastModifiedInstant.compareTo(maxAge) < 0;
+			} catch (final IOException e) {
+				LOGGER.warn("failed to get last modified time of " + path + ". Considering this file as stale.", e);
+				return true;
+			}
+		}
+
+	}
+
+	private final ScheduledExecutorService scheduledThreadPool;
+
+	@Autowired
+	public CleanupThread(@Value("${" + PATH_GENERATED_IMAGES + "}") final String outputDir,
+			@Value("${" + CACHE_IMAGES_DURATION_SECONDS + ":" + CACHE_IMAGES_DURATION_SECONDS_DEFAULT
+					+ "}") final int cacheDurationInSeconds) {
+		scheduledThreadPool = Executors.newScheduledThreadPool(1, new CustomizableThreadFactory("cleanup-"));
+
+		final Path outputPath = Paths.get(outputDir);
+		scheduledThreadPool.scheduleWithFixedDelay(new RemoveTempFiles(outputPath, cacheDurationInSeconds), 1, 5,
+				TimeUnit.MINUTES);
+	}
+
+	@Override
+	public void destroy() {
+		scheduledThreadPool.shutdown();
+		try {
+			scheduledThreadPool.awaitTermination(10, TimeUnit.SECONDS);
+		} catch (final InterruptedException e) {
+			Thread.currentThread().interrupt();
+		}
+	}
+
+}