Java tutorial
/* * Copyright 2008-present 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 com.mongodb.gridfs; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; import com.mongodb.MongoException; import org.bson.BSONObject; import java.util.Collections; import java.util.Date; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import static java.util.Arrays.asList; /** * The abstract class representing a GridFS file. * * @mongodb.driver.manual core/gridfs/ GridFS */ public abstract class GridFSFile implements DBObject { private static final Set<String> VALID_FIELDS = Collections.unmodifiableSet(new HashSet<String>( asList("_id", "filename", "contentType", "length", "chunkSize", "uploadDate", "aliases", "md5"))); final DBObject extra = new BasicDBObject(); GridFS fs; Object id; String filename; String contentType; long length; long chunkSize; Date uploadDate; String md5; /** * Saves the file entry to the files collection * * @throws MongoException if there's a failure */ public void save() { if (fs == null) { throw new MongoException("need fs"); } fs.getFilesCollection().save(this); } /** * Verifies that the MD5 matches between the database and the local file. This should be called after transferring a file. * * @throws MongoException if there's a failure * @deprecated there is no replacement for this method */ @Deprecated public void validate() { if (fs == null) { throw new MongoException("no fs"); } if (md5 == null) { throw new MongoException("no md5 stored"); } DBObject cmd = new BasicDBObject("filemd5", id); cmd.put("root", fs.getBucketName()); DBObject res = fs.getDB().command(cmd); if (res != null && res.containsField("md5")) { String m = res.get("md5").toString(); if (m.equals(md5)) { return; } throw new MongoException("md5 differ. mine [" + md5 + "] theirs [" + m + "]"); } // no md5 from the server throw new MongoException("no md5 returned from server: " + res); } /** * Returns the number of chunks that store the file data. * * @return number of chunks */ public int numChunks() { double d = length; d = d / chunkSize; return (int) Math.ceil(d); } /** * Gets the id. * * @return the id of the file. */ public Object getId() { return id; } /** * Gets the filename. * * @return the name of the file */ public String getFilename() { return filename; } /** * Gets the content type. * * @return the content type */ public String getContentType() { return contentType; } /** * Gets the file's length. * * @return the length of the file */ public long getLength() { return length; } /** * Gets the size of a chunk. * * @return the chunkSize */ public long getChunkSize() { return chunkSize; } /** * Gets the upload date. * * @return the date */ public Date getUploadDate() { return uploadDate; } /** * Gets the aliases from the metadata. note: to set aliases, call {@link #put(String, Object)} with {@code "aliases" , List<String>}. * * @return list of aliases */ @SuppressWarnings("unchecked") public List<String> getAliases() { return (List<String>) extra.get("aliases"); } /** * Gets the file metadata. * * @return the metadata */ public DBObject getMetaData() { return (DBObject) extra.get("metadata"); } /** * Gets the file metadata. * * @param metadata metadata to be set */ public void setMetaData(final DBObject metadata) { extra.put("metadata", metadata); } /** * Gets the observed MD5 during transfer * * @return md5 * @deprecated there is no replacement for this method */ @Deprecated public String getMD5() { return md5; } @Override public Object put(final String key, final Object v) { if (key == null) { throw new RuntimeException("key should never be null"); } else if (key.equals("_id")) { id = v; } else if (key.equals("filename")) { filename = v == null ? null : v.toString(); } else if (key.equals("contentType")) { contentType = (String) v; } else if (key.equals("length")) { length = ((Number) v).longValue(); } else if (key.equals("chunkSize")) { chunkSize = ((Number) v).longValue(); } else if (key.equals("uploadDate")) { uploadDate = (Date) v; } else if (key.equals("md5")) { md5 = (String) v; } else { extra.put(key, v); } return v; } @Override public Object get(final String key) { if (key == null) { throw new IllegalArgumentException("Key should never be null"); } else if (key.equals("_id")) { return id; } else if (key.equals("filename")) { return filename; } else if (key.equals("contentType")) { return contentType; } else if (key.equals("length")) { return length; } else if (key.equals("chunkSize")) { return chunkSize; } else if (key.equals("uploadDate")) { return uploadDate; } else if (key.equals("md5")) { return md5; } return extra.get(key); } @Override @Deprecated public boolean containsKey(final String key) { return containsField(key); } @Override public boolean containsField(final String s) { return keySet().contains(s); } @Override public Set<String> keySet() { Set<String> keys = new HashSet<String>(); keys.addAll(VALID_FIELDS); keys.addAll(extra.keySet()); return keys; } @Override public boolean isPartialObject() { return false; } @Override public void markAsPartialObject() { throw new MongoException("Can't load partial GridFSFile file"); } @Override @SuppressWarnings("deprecation") public String toString() { return com.mongodb.util.JSON.serialize(this); } /** * Sets the GridFS associated with this file. * * @param fs gridFS instance */ protected void setGridFS(final GridFS fs) { this.fs = fs; } /** * Gets the GridFS associated with this file * * @return gridFS instance */ protected GridFS getGridFS() { return this.fs; } @Override public void putAll(final BSONObject o) { throw new UnsupportedOperationException(); } @Override public void putAll(@SuppressWarnings("rawtypes") final Map m) { throw new UnsupportedOperationException(); } @Override public Map<?, ?> toMap() { throw new UnsupportedOperationException(); } @Override public Object removeField(final String key) { throw new UnsupportedOperationException(); } }