Example usage for com.mongodb.client.gridfs GridFSBucket find

Introduction

In this page you can find the example usage for com.mongodb.client.gridfs GridFSBucket find.

Prototype

GridFSFindIterable find();

Source Link

Document

Finds all documents in the files collection.

Usage

From source file:gridfs.GridFSTour.java

License:Apache License

/**
 * Run this main method to see the output of this quick example.
 *
 * @param args takes an optional single argument for the connection string
 * @throws FileNotFoundException if the sample file cannot be found
 * @throws IOException if there was an exception closing an input stream
 *///  ww w  .ja v a2  s .c om
public static void main(final String[] args) throws FileNotFoundException, IOException {
    MongoClient mongoClient;

    if (args.length == 0) {
        // connect to the local database server
        mongoClient = new MongoClient();
    } else {
        mongoClient = new MongoClient(new MongoClientURI(args[0]));
    }

    // get handle to "mydb" database
    MongoDatabase database = mongoClient.getDatabase("mydb");
    database.drop();

    GridFSBucket gridFSBucket = GridFSBuckets.create(database);

    /*
     * UploadFromStream Example
     */
    // Get the input stream
    InputStream streamToUploadFrom = new ByteArrayInputStream("Hello World".getBytes(StandardCharsets.UTF_8));

    // Create some custom options
    GridFSUploadOptions options = new GridFSUploadOptions().chunkSizeBytes(1024)
            .metadata(new Document("type", "presentation"));

    ObjectId fileId = gridFSBucket.uploadFromStream("mongodb-tutorial", streamToUploadFrom, options);
    streamToUploadFrom.close();
    System.out.println("The fileId of the uploaded file is: " + fileId.toHexString());

    /*
     * OpenUploadStream Example
     */

    // Get some data to write
    byte[] data = "Data to upload into GridFS".getBytes(StandardCharsets.UTF_8);

    GridFSUploadStream uploadStream = gridFSBucket.openUploadStream("sampleData");
    uploadStream.write(data);
    uploadStream.close();
    System.out.println("The fileId of the uploaded file is: " + uploadStream.getFileId().toHexString());

    /*
     * Find documents
     */
    gridFSBucket.find().forEach(new Block<GridFSFile>() {
        @Override
        public void apply(final GridFSFile gridFSFile) {
            System.out.println(gridFSFile.getFilename());
        }
    });

    /*
     * Find documents with a filter
     */
    gridFSBucket.find(eq("metadata.contentType", "image/png")).forEach(new Block<GridFSFile>() {
        @Override
        public void apply(final GridFSFile gridFSFile) {
            System.out.println(gridFSFile.getFilename());
        }
    });

    /*
     * DownloadToStream
     */
    FileOutputStream streamToDownloadTo = new FileOutputStream("/tmp/mongodb-tutorial.txt");
    gridFSBucket.downloadToStream(fileId, streamToDownloadTo);
    streamToDownloadTo.close();

    /*
     * DownloadToStreamByName
     */
    streamToDownloadTo = new FileOutputStream("/tmp/mongodb-tutorial.txt");
    GridFSDownloadByNameOptions downloadOptions = new GridFSDownloadByNameOptions().revision(0);
    gridFSBucket.downloadToStreamByName("mongodb-tutorial", streamToDownloadTo, downloadOptions);
    streamToDownloadTo.close();

    /*
     * OpenDownloadStream
     */
    GridFSDownloadStream downloadStream = gridFSBucket.openDownloadStream(fileId);
    int fileLength = (int) downloadStream.getGridFSFile().getLength();
    byte[] bytesToWriteTo = new byte[fileLength];
    downloadStream.read(bytesToWriteTo);
    downloadStream.close();

    System.out.println(new String(bytesToWriteTo, StandardCharsets.UTF_8));

    /*
     * OpenDownloadStreamByName
     */

    downloadStream = gridFSBucket.openDownloadStreamByName("sampleData");
    fileLength = (int) downloadStream.getGridFSFile().getLength();
    bytesToWriteTo = new byte[fileLength];
    downloadStream.read(bytesToWriteTo);
    downloadStream.close();

    System.out.println(new String(bytesToWriteTo, StandardCharsets.UTF_8));

    /*
     * Rename
     */
    gridFSBucket.rename(fileId, "mongodbTutorial");

    /*
     * Delete
     */
    gridFSBucket.delete(fileId);

    database.drop();
}

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