Java tutorial
/* * Copyright 2015 MongoDB, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package gridfs; import com.mongodb.Block; import com.mongodb.MongoClient; import com.mongodb.MongoClientURI; import com.mongodb.client.MongoDatabase; import com.mongodb.client.gridfs.GridFSBucket; import com.mongodb.client.gridfs.GridFSBuckets; import com.mongodb.client.gridfs.GridFSDownloadStream; import com.mongodb.client.gridfs.GridFSUploadStream; import com.mongodb.client.gridfs.model.GridFSDownloadByNameOptions; import com.mongodb.client.gridfs.model.GridFSFile; import com.mongodb.client.gridfs.model.GridFSUploadOptions; import org.bson.Document; import org.bson.types.ObjectId; import java.io.ByteArrayInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.nio.charset.StandardCharsets; import static com.mongodb.client.model.Filters.eq; /** * The GridFS code example see: https://mongodb.github.io/mongo-java-driver/3.1/driver/reference/gridfs */ public final class GridFSTour { /** * 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 */ 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(); } private GridFSTour() { } }