commit 7439fa933c9b686a8650d0b9d5c398fdd434f749 Author: Karsten Loesing <karsten.loesing@gmx.net> Date: Tue Dec 1 22:32:46 2020 +0100 Use persist package for writing bridge descriptors. Implements #25307. --- .../bridgedescs/SanitizedBridgesWriter.java | 104 +++------------------ .../BridgeExtraInfoDescriptorPersistence.java | 54 +++++++++++ .../persist/BridgeExtraInfoPersistence.java | 39 -------- .../persist/BridgeNetworkStatusPersistence.java | 56 +++++++++++ .../persist/BridgeServerDescriptorPersistence.java | 43 ++++++--- .../collector/persist/DescriptorPersistence.java | 40 +++++--- .../collector/persist/StatusPersistence.java | 41 -------- .../metrics/collector/sync/SyncPersistence.java | 10 +- .../bridgedescs/SanitizedBridgesWriterTest.java | 2 +- 9 files changed, 188 insertions(+), 201 deletions(-) diff --git a/src/main/java/org/torproject/metrics/collector/bridgedescs/SanitizedBridgesWriter.java b/src/main/java/org/torproject/metrics/collector/bridgedescs/SanitizedBridgesWriter.java index 5e24f5d..7619453 100644 --- a/src/main/java/org/torproject/metrics/collector/bridgedescs/SanitizedBridgesWriter.java +++ b/src/main/java/org/torproject/metrics/collector/bridgedescs/SanitizedBridgesWriter.java @@ -10,6 +10,9 @@ import org.torproject.metrics.collector.conf.Configuration; import org.torproject.metrics.collector.conf.ConfigurationException; import org.torproject.metrics.collector.conf.Key; import org.torproject.metrics.collector.cron.CollecTorMain; +import org.torproject.metrics.collector.persist.BridgeExtraInfoDescriptorPersistence; +import org.torproject.metrics.collector.persist.BridgeNetworkStatusPersistence; +import org.torproject.metrics.collector.persist.BridgeServerDescriptorPersistence; import org.torproject.metrics.collector.persist.PersistenceUtils; import org.apache.commons.codec.binary.Hex; @@ -28,8 +31,6 @@ import java.io.StringReader; import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.nio.file.Path; -import java.nio.file.Paths; -import java.nio.file.StandardOpenOption; import java.time.Instant; import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; @@ -57,7 +58,6 @@ public class SanitizedBridgesWriter extends CollecTorMain { private static final Logger logger = LoggerFactory.getLogger( SanitizedBridgesWriter.class); - private static final String BRIDGE_DESCRIPTORS = "bridge-descriptors"; /** Initialize configuration. */ public SanitizedBridgesWriter(Configuration config) { @@ -91,10 +91,8 @@ public class SanitizedBridgesWriter extends CollecTorMain { @Override protected void startProcessing() throws ConfigurationException { - this.outputDirectory = config.getPath(Key.OutputPath) - .resolve(BRIDGE_DESCRIPTORS); - this.recentDirectory = config.getPath(Key.RecentPath) - .resolve(BRIDGE_DESCRIPTORS); + this.outputDirectory = config.getPath(Key.OutputPath); + this.recentDirectory = config.getPath(Key.RecentPath); Path inputDirectory = config.getPath(Key.BridgeLocalOrigins); Path statsDirectory = config.getPath(Key.StatsPath); boolean replaceIpAddressesWithHashes = @@ -352,27 +350,9 @@ public class SanitizedBridgesWriter extends CollecTorMain { || publicationTime.compareTo(maxNetworkStatusPublishedTime) > 0) { maxNetworkStatusPublishedTime = publicationTime; } - try { - String syear = publicationTime.substring(0, 4); - String smonth = publicationTime.substring(5, 7); - String sday = publicationTime.substring(8, 10); - String stime = publicationTime.substring(11, 13) - + publicationTime.substring(14, 16) - + publicationTime.substring(17, 19); - String fileName = syear + smonth + sday + "-" + stime + "-" - + authorityFingerprint; - Path tarballFile = this.outputDirectory.resolve( - Paths.get(syear, smonth, "statuses", sday, fileName)); - Path rsyncFile = this.recentDirectory.resolve( - Paths.get("statuses", fileName)); - for (Path outputFile : new Path[] { tarballFile, rsyncFile }) { - Files.createDirectories(outputFile.getParent()); - Files.write(outputFile, scrubbedBytes); - } - } catch (IOException e) { - logger.warn("Could not write sanitized bridge " - + "network status to disk.", e); - } + new BridgeNetworkStatusPersistence(scrubbedBytes, publicationTime, + authorityFingerprint) + .storeAll(this.recentDirectory, this.outputDirectory); } private String maxServerDescriptorPublishedTime = null; @@ -398,36 +378,9 @@ public class SanitizedBridgesWriter extends CollecTorMain { } String descriptorDigest = sanitizedBridgeServerDescriptor.getDescriptorDigest(); - - /* Determine filename of sanitized server descriptor. */ - String dyear = published.substring(0, 4); - String dmonth = published.substring(5, 7); - try { - Path tarballFile = this.outputDirectory.resolve( - Paths.get(dyear, dmonth, "server-descriptors", - descriptorDigest.substring(0, 1), descriptorDigest.substring(1, 2), - descriptorDigest)); - Path rsyncCatFile = this.recentDirectory.resolve( - Paths.get("bridge-descriptors", "server-descriptors", - this.rsyncCatString + "-server-descriptors.tmp")); - Path[] outputFiles = new Path[] { tarballFile, rsyncCatFile }; - boolean[] append = new boolean[] { false, true }; - for (int i = 0; i < outputFiles.length; i++) { - Path outputFile = outputFiles[i]; - StandardOpenOption openOption = append[i] ? StandardOpenOption.APPEND - : StandardOpenOption.CREATE_NEW; - if (Files.exists(outputFile) - && openOption != StandardOpenOption.APPEND) { - /* We already stored this descriptor to disk before, so let's - * not store it yet another time. */ - break; - } - Files.createDirectories(outputFile.getParent()); - Files.write(outputFile, scrubbedBytes, openOption); - } - } catch (IOException e) { - logger.warn("Could not write sanitized server descriptor to disk.", e); - } + new BridgeServerDescriptorPersistence(scrubbedBytes, published, + this.rsyncCatString, descriptorDigest) + .storeAll(this.recentDirectory, this.outputDirectory); } private String maxExtraInfoDescriptorPublishedTime = null; @@ -453,38 +406,9 @@ public class SanitizedBridgesWriter extends CollecTorMain { } String descriptorDigest = sanitizedBridgeExtraInfoDescriptor.getDescriptorDigest(); - - /* Determine filename of sanitized extra-info descriptor. */ - String dyear = published.substring(0, 4); - String dmonth = published.substring(5, 7); - - try { - Path tarballFile = this.outputDirectory.resolve( - Paths.get(dyear, dmonth, "extra-infos", - descriptorDigest.substring(0, 1), descriptorDigest.substring(1, 2), - descriptorDigest)); - Path rsyncCatFile = this.recentDirectory.resolve( - Paths.get("bridge-descriptors", "extra-infos", - this.rsyncCatString + "-extra-infos.tmp")); - Path[] outputFiles = new Path[] { tarballFile, rsyncCatFile }; - boolean[] append = new boolean[] { false, true }; - for (int i = 0; i < outputFiles.length; i++) { - Path outputFile = outputFiles[i]; - StandardOpenOption openOption = append[i] ? StandardOpenOption.APPEND - : StandardOpenOption.CREATE_NEW; - if (Files.exists(outputFile) - && openOption != StandardOpenOption.APPEND) { - /* We already stored this descriptor to disk before, so let's - * not store it yet another time. */ - break; - } - Files.createDirectories(outputFile.getParent()); - Files.write(outputFile, scrubbedBytes, openOption); - } - } catch (IOException e) { - logger.warn("Could not write sanitized extra-info descriptor to disk.", - e); - } + new BridgeExtraInfoDescriptorPersistence(scrubbedBytes, published, + this.rsyncCatString, descriptorDigest) + .storeAll(this.recentDirectory, this.outputDirectory); } private void checkStaleDescriptors() { diff --git a/src/main/java/org/torproject/metrics/collector/persist/BridgeExtraInfoDescriptorPersistence.java b/src/main/java/org/torproject/metrics/collector/persist/BridgeExtraInfoDescriptorPersistence.java new file mode 100644 index 0000000..712d6f4 --- /dev/null +++ b/src/main/java/org/torproject/metrics/collector/persist/BridgeExtraInfoDescriptorPersistence.java @@ -0,0 +1,54 @@ +/* Copyright 2016--2020 The Tor Project + * See LICENSE for licensing information */ + +package org.torproject.metrics.collector.persist; + +import org.torproject.descriptor.BridgeExtraInfoDescriptor; +import org.torproject.metrics.collector.conf.Annotation; + +import java.nio.file.Paths; + +public class BridgeExtraInfoDescriptorPersistence + extends DescriptorPersistence<BridgeExtraInfoDescriptor> { + + /** + * Construct a persistence instance from a previously parsed descriptor. + */ + public BridgeExtraInfoDescriptorPersistence( + BridgeExtraInfoDescriptor descriptor, long received) { + super(descriptor, Annotation.BridgeExtraInfo.bytes()); + this.calculatePaths( + PersistenceUtils.dateTimeParts(descriptor.getPublishedMillis()), + PersistenceUtils.dateTime(received), + descriptor.getDigestSha1Hex().toLowerCase()); + } + + /** + * Construct a persistence instance from raw descriptor bytes. + */ + public BridgeExtraInfoDescriptorPersistence(byte[] descriptorBytes, + String publishedString, String receivedString, String descriptorDigest) { + super(descriptorBytes); + this.calculatePaths( + publishedString.split("[ :-]"), + receivedString, + descriptorDigest.toLowerCase()); + } + + private void calculatePaths(String[] publishedParts, String receivedString, + String descriptorDigest) { + this.recentPath = Paths.get( + BRIDGEDESCS, + EXTRA_INFOS, + receivedString + DASH + EXTRA_INFOS).toString(); + this.storagePath = Paths.get( + BRIDGEDESCS, + publishedParts[0], // year + publishedParts[1], // month + EXTRA_INFOS, + descriptorDigest.substring(0, 1), + descriptorDigest.substring(1, 2), + descriptorDigest).toString(); + } +} + diff --git a/src/main/java/org/torproject/metrics/collector/persist/BridgeExtraInfoPersistence.java b/src/main/java/org/torproject/metrics/collector/persist/BridgeExtraInfoPersistence.java deleted file mode 100644 index 04cb473..0000000 --- a/src/main/java/org/torproject/metrics/collector/persist/BridgeExtraInfoPersistence.java +++ /dev/null @@ -1,39 +0,0 @@ -/* Copyright 2016--2020 The Tor Project - * See LICENSE for licensing information */ - -package org.torproject.metrics.collector.persist; - -import org.torproject.descriptor.BridgeExtraInfoDescriptor; -import org.torproject.metrics.collector.conf.Annotation; - -import java.nio.file.Paths; - -public class BridgeExtraInfoPersistence - extends DescriptorPersistence<BridgeExtraInfoDescriptor> { - - public BridgeExtraInfoPersistence(BridgeExtraInfoDescriptor desc, - long received) { - super(desc, Annotation.BridgeExtraInfo.bytes()); - calculatePaths(received); - } - - private void calculatePaths(long received) { - String file = PersistenceUtils.dateTime(received); - String[] parts = PersistenceUtils.dateTimeParts(desc.getPublishedMillis()); - this.recentPath = Paths.get( - BRIDGEDESCS, - EXTRA_INFOS, - file + DASH + EXTRA_INFOS).toString(); - String digest = desc.getDigestSha1Hex().toLowerCase(); - this.storagePath = Paths.get( - BRIDGEDESCS, - parts[0], // year - parts[1], // month - EXTRA_INFOS, - digest.substring(0,1), - digest.substring(1,2), - digest).toString(); - } - -} - diff --git a/src/main/java/org/torproject/metrics/collector/persist/BridgeNetworkStatusPersistence.java b/src/main/java/org/torproject/metrics/collector/persist/BridgeNetworkStatusPersistence.java new file mode 100644 index 0000000..60b341a --- /dev/null +++ b/src/main/java/org/torproject/metrics/collector/persist/BridgeNetworkStatusPersistence.java @@ -0,0 +1,56 @@ +/* Copyright 2016--2020 The Tor Project + * See LICENSE for licensing information */ + +package org.torproject.metrics.collector.persist; + +import org.torproject.descriptor.BridgeNetworkStatus; +import org.torproject.metrics.collector.conf.Annotation; + +import java.nio.file.Paths; + +public class BridgeNetworkStatusPersistence + extends DescriptorPersistence<BridgeNetworkStatus> { + + private static final String STATUSES = "statuses"; + + /** + * Construct a persistence instance from a previously parsed descriptor. + */ + public BridgeNetworkStatusPersistence(BridgeNetworkStatus descriptor, + String authorityFingerprint) { + super(descriptor, Annotation.Status.bytes()); + this.calculatePaths( + PersistenceUtils.dateTimeParts(descriptor.getPublishedMillis()), + authorityFingerprint); + } + + /** + * Construct a persistence instance from raw descriptor bytes. + */ + public BridgeNetworkStatusPersistence(byte[] descriptorBytes, + String published, String authorityFingerprint) { + super(descriptorBytes); + this.calculatePaths( + published.split("[ :-]"), + authorityFingerprint); + } + + private void calculatePaths(String[] publishedParts, + String authorityFingerprint) { + String fileOut = publishedParts[0] + publishedParts[1] + publishedParts[2] + + DASH + publishedParts[3] + publishedParts[4] + publishedParts[5] + + DASH + authorityFingerprint; + this.recentPath = Paths.get( + BRIDGEDESCS, + STATUSES, + fileOut).toString(); + this.storagePath = Paths.get( + BRIDGEDESCS, + publishedParts[0], // year + publishedParts[1], // month + STATUSES, + publishedParts[2], // day + fileOut).toString(); + } +} + diff --git a/src/main/java/org/torproject/metrics/collector/persist/BridgeServerDescriptorPersistence.java b/src/main/java/org/torproject/metrics/collector/persist/BridgeServerDescriptorPersistence.java index 27c37d0..3f308b4 100644 --- a/src/main/java/org/torproject/metrics/collector/persist/BridgeServerDescriptorPersistence.java +++ b/src/main/java/org/torproject/metrics/collector/persist/BridgeServerDescriptorPersistence.java @@ -11,29 +11,44 @@ import java.nio.file.Paths; public class BridgeServerDescriptorPersistence extends DescriptorPersistence<BridgeServerDescriptor> { - public BridgeServerDescriptorPersistence(BridgeServerDescriptor desc, + /** + * Construct a persistence instance from a previously parsed descriptor. + */ + public BridgeServerDescriptorPersistence(BridgeServerDescriptor descriptor, long received) { - super(desc, Annotation.BridgeServer.bytes()); - calculatePaths(received); + super(descriptor, Annotation.BridgeServer.bytes()); + this.calculatePaths( + PersistenceUtils.dateTimeParts(descriptor.getPublishedMillis()), + PersistenceUtils.dateTime(received), + descriptor.getDigestSha1Hex().toLowerCase()); } - private void calculatePaths(long received) { - String file = PersistenceUtils.dateTime(received); - String[] parts = PersistenceUtils.dateTimeParts(desc.getPublishedMillis()); + /** + * Construct a persistence instance from raw descriptor bytes. + */ + public BridgeServerDescriptorPersistence(byte[] descriptorBytes, + String publishedString, String receivedString, String descriptorDigest) { + super(descriptorBytes); + this.calculatePaths( + publishedString.split("[ :-]"), + receivedString, + descriptorDigest.toLowerCase()); + } + + private void calculatePaths(String[] publishedParts, String receivedString, + String descriptorDigest) { this.recentPath = Paths.get( BRIDGEDESCS, SERVERDESCS, - file + DASH + SERVERDESCS).toString(); - String digest = desc.getDigestSha1Hex().toLowerCase(); + receivedString + DASH + SERVERDESCS).toString(); this.storagePath = Paths.get( BRIDGEDESCS, - parts[0], // year - parts[1], // month + publishedParts[0], // year + publishedParts[1], // month SERVERDESCS, - digest.substring(0,1), - digest.substring(1,2), - digest).toString(); + descriptorDigest.substring(0, 1), + descriptorDigest.substring(1, 2), + descriptorDigest).toString(); } - } diff --git a/src/main/java/org/torproject/metrics/collector/persist/DescriptorPersistence.java b/src/main/java/org/torproject/metrics/collector/persist/DescriptorPersistence.java index a2c9bc4..87df2b7 100644 --- a/src/main/java/org/torproject/metrics/collector/persist/DescriptorPersistence.java +++ b/src/main/java/org/torproject/metrics/collector/persist/DescriptorPersistence.java @@ -5,6 +5,7 @@ package org.torproject.metrics.collector.persist; import org.torproject.descriptor.Descriptor; +import java.nio.file.Path; import java.nio.file.Paths; import java.nio.file.StandardOpenOption; import java.util.List; @@ -26,26 +27,43 @@ public abstract class DescriptorPersistence<T extends Descriptor> { protected static final String SERVERDESCS = "server-descriptors"; protected static final String WEBSTATS = "webstats"; - protected final T desc; - protected final byte[] annotation; + protected T desc; + + protected final byte[] annotationBytes; + protected final byte[] descriptorBytes; protected String storagePath; protected String recentPath; + protected static final byte[] EMPTY_ANNOTATION = new byte[0]; + /** * Initializes the paths for storing descriptors of type {@code T}. */ - protected DescriptorPersistence(T desc, byte[] defaultAnnotation) { - this.desc = desc; - List<String> annotations = desc.getAnnotations(); + protected DescriptorPersistence(T descriptor, byte[] defaultAnnotationBytes) { + this.desc = descriptor; + List<String> annotations = descriptor.getAnnotations(); if (annotations.isEmpty()) { - this.annotation = defaultAnnotation; + this.annotationBytes = defaultAnnotationBytes; } else { StringBuilder sb = new StringBuilder(); for (String annotation : annotations) { sb.append(annotation).append("\n"); } - this.annotation = sb.toString().getBytes(); + this.annotationBytes = sb.toString().getBytes(); } + this.descriptorBytes = descriptor.getRawDescriptorBytes(); + } + + protected DescriptorPersistence(byte[] descriptorBytes) { + this.annotationBytes = EMPTY_ANNOTATION; + this.descriptorBytes = descriptorBytes; + } + + /** Stores the descriptor to all locations. + * First attempt to store the 'out' path, if that works store to 'recent'. + * Returns {@code true}, if both were written. */ + public boolean storeAll(Path recentRoot, Path outRoot) { + return storeAll(recentRoot.toString(), outRoot.toString()); } /** Stores the descriptor to all locations. @@ -77,8 +95,8 @@ public abstract class DescriptorPersistence<T extends Descriptor> { * Creates, replaces, or appends according to the given option. * Returns {@code true}, if the file was written. */ public boolean storeRecent(String recentRoot, StandardOpenOption option) { - return PersistenceUtils.storeToFileSystem(annotation, - desc.getRawDescriptorBytes(), Paths.get(recentRoot, getRecentPath()), + return PersistenceUtils.storeToFileSystem(this.annotationBytes, + this.descriptorBytes, Paths.get(recentRoot, getRecentPath()), option, true); } @@ -93,8 +111,8 @@ public abstract class DescriptorPersistence<T extends Descriptor> { * Creates, replaces, or appends according to the given option. * Returns {@code true}, if the file was written. */ public boolean storeOut(String outRoot, StandardOpenOption option) { - return PersistenceUtils.storeToFileSystem(annotation, - desc.getRawDescriptorBytes(), Paths.get(outRoot, getStoragePath()), + return PersistenceUtils.storeToFileSystem(annotationBytes, + this.descriptorBytes, Paths.get(outRoot, getStoragePath()), option); } diff --git a/src/main/java/org/torproject/metrics/collector/persist/StatusPersistence.java b/src/main/java/org/torproject/metrics/collector/persist/StatusPersistence.java deleted file mode 100644 index c379410..0000000 --- a/src/main/java/org/torproject/metrics/collector/persist/StatusPersistence.java +++ /dev/null @@ -1,41 +0,0 @@ -/* Copyright 2016--2020 The Tor Project - * See LICENSE for licensing information */ - -package org.torproject.metrics.collector.persist; - -import org.torproject.descriptor.BridgeNetworkStatus; -import org.torproject.metrics.collector.conf.Annotation; - -import java.nio.file.Paths; - -public class StatusPersistence - extends DescriptorPersistence<BridgeNetworkStatus> { - - private static final String STATUSES = "statuses"; - - public StatusPersistence(BridgeNetworkStatus desc, - String authId, long received) { - super(desc, Annotation.Status.bytes()); - calculatePaths(authId, received); - } - - private void calculatePaths(String authId, long received) { - String[] partsOut = PersistenceUtils.dateTimeParts( - desc.getPublishedMillis()); - String fileOut = partsOut[0] + partsOut[1] + partsOut[2] + DASH - + partsOut[3] + partsOut[4] + partsOut[5] + DASH + authId; - this.recentPath = Paths.get( - BRIDGEDESCS, - STATUSES, - fileOut).toString(); - this.storagePath = Paths.get( - BRIDGEDESCS, - partsOut[0], // year - partsOut[1], // month - STATUSES, - partsOut[2], // day - fileOut).toString(); - } - -} - diff --git a/src/main/java/org/torproject/metrics/collector/sync/SyncPersistence.java b/src/main/java/org/torproject/metrics/collector/sync/SyncPersistence.java index af48b1f..bbb61b7 100644 --- a/src/main/java/org/torproject/metrics/collector/sync/SyncPersistence.java +++ b/src/main/java/org/torproject/metrics/collector/sync/SyncPersistence.java @@ -22,7 +22,8 @@ import org.torproject.metrics.collector.conf.Configuration; import org.torproject.metrics.collector.conf.ConfigurationException; import org.torproject.metrics.collector.conf.Key; import org.torproject.metrics.collector.persist.BandwidthFilePersistence; -import org.torproject.metrics.collector.persist.BridgeExtraInfoPersistence; +import org.torproject.metrics.collector.persist.BridgeExtraInfoDescriptorPersistence; +import org.torproject.metrics.collector.persist.BridgeNetworkStatusPersistence; import org.torproject.metrics.collector.persist.BridgePoolAssignmentPersistence; import org.torproject.metrics.collector.persist.BridgeServerDescriptorPersistence; import org.torproject.metrics.collector.persist.BridgedbMetricsPersistence; @@ -35,7 +36,6 @@ import org.torproject.metrics.collector.persist.OnionPerfPersistence; import org.torproject.metrics.collector.persist.PersistenceUtils; import org.torproject.metrics.collector.persist.ServerDescriptorPersistence; import org.torproject.metrics.collector.persist.SnowflakeStatsPersistence; -import org.torproject.metrics.collector.persist.StatusPersistence; import org.torproject.metrics.collector.persist.VotePersistence; import org.torproject.metrics.collector.persist.WebServerAccessLogPersistence; @@ -111,7 +111,7 @@ public class SyncPersistence { (RelayServerDescriptor) desc, received); break; case "BridgeExtraInfoDescriptor": - descPersist = new BridgeExtraInfoPersistence( + descPersist = new BridgeExtraInfoDescriptorPersistence( (BridgeExtraInfoDescriptor) desc, received); break; case "RelayExtraInfoDescriptor": @@ -125,8 +125,8 @@ public class SyncPersistence { filename); break; } - descPersist = new StatusPersistence( - (BridgeNetworkStatus) desc, filenameParts[2], received); + descPersist = new BridgeNetworkStatusPersistence( + (BridgeNetworkStatus) desc, filenameParts[2]); break; case "BridgeServerDescriptor": descPersist = new BridgeServerDescriptorPersistence( diff --git a/src/test/java/org/torproject/metrics/collector/bridgedescs/SanitizedBridgesWriterTest.java b/src/test/java/org/torproject/metrics/collector/bridgedescs/SanitizedBridgesWriterTest.java index d8c7119..4c96aee 100644 --- a/src/test/java/org/torproject/metrics/collector/bridgedescs/SanitizedBridgesWriterTest.java +++ b/src/test/java/org/torproject/metrics/collector/bridgedescs/SanitizedBridgesWriterTest.java @@ -151,7 +151,7 @@ public class SanitizedBridgesWriterTest { this.parsedServerDescriptors = new ArrayList<>(); this.parsedExtraInfoDescriptors = new ArrayList<>(); this.parsedNetworkStatuses = new ArrayList<>(); - Files.walkFileTree(sanitizedBridgesDirectory, + Files.walkFileTree(sanitizedBridgesDirectory.getParent(), new SimpleFileVisitor<Path>() { @Override public FileVisitResult visitFile(Path path, BasicFileAttributes bfa)