Example usage for java.nio.file Files newDirectoryStream

Introduction

In this page you can find the example usage for java.nio.file Files newDirectoryStream.

Prototype

public static DirectoryStream<Path> newDirectoryStream(Path dir, DirectoryStream.Filter<? super Path> filter)
        throws IOException

Source Link

Document

Opens a directory, returning a DirectoryStream to iterate over the entries in the directory.

Usage

From source file:org.elassandra.index.ElasticSecondaryIndex.java

/**
 * Cassandra table snapshot => hard links associated elasticsearch lucene files.
 *///from   w  w  w  .ja  v  a 2  s  . co  m
@SuppressForbidden(reason = "File used for snapshots")
public Callable<?> getSnapshotWithoutFlushTask(String snapshotName) {
    return () -> {
        if (isIndexing()) {
            for (ImmutableMappingInfo.ImmutableIndexInfo indexInfo : mappingInfo.indices) {
                IndexShard indexShard = indexInfo.indexService.shard(0);
                if (indexShard != null && indexInfo.snapshot) {
                    if (indexShard.state() == IndexShardState.STARTED) {
                        // snapshotPath = data/elasticsearch.data/<cluster_name>/nodes/0/snapshots
                        Path snapshotPath = indexShard.shardPath().resolveSnapshot();
                        if ((Files.notExists(snapshotPath)))
                            Files.createDirectory(snapshotPath, snapshotDirPermissions);

                        // snapshotIndex = data/elasticsearch.data/<cluster_name>/nodes/0/snapshots/<index_name>
                        Path snapshotIndex = snapshotPath.resolve(indexShard.shardId().getIndex());
                        if ((Files.notExists(snapshotIndex)))
                            Files.createDirectory(snapshotIndex, snapshotDirPermissions);

                        // snapshotDir = data/elasticsearch.data/<cluster_name>/nodes/0/snapshots/<index_name>/<snapshot_name>
                        Path snapshotDir = Files.createDirectory(snapshotIndex.resolve(snapshotName),
                                snapshotDirPermissions);
                        Path indexPath = indexShard.shardPath().resolveIndex();

                        try (DirectoryStream<Path> stream = Files.newDirectoryStream(indexPath,
                                "{_*.*,segments*}")) {
                            for (Path luceneFile : stream) {
                                File targetLink = new File(snapshotDir.toFile(),
                                        luceneFile.getFileName().toString());
                                FileUtils.createHardLink(luceneFile.toFile(), targetLink);
                            }
                            if (logger.isDebugEnabled())
                                logger.debug("Elasticsearch index=[{}], snapshot=[{}], path=[{}]",
                                        indexInfo.name, snapshotName, snapshotDir.toString());
                        } catch (DirectoryIteratorException ex) {
                            logger.error("Failed to retreive lucene files in {}", ex, indexPath);
                        }
                    } else {
                        if (logger.isDebugEnabled())
                            logger.debug("Cannot snapshot index=[{}], state=[{}], snapshot=[{}]",
                                    indexInfo.name, indexShard.state(), snapshotName);
                    }
                }
            }
        }
        return null;
    };
}