Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.camel.component.gridfs; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.io.Reader; import com.mongodb.BasicDBObject; import com.mongodb.DBCursor; import com.mongodb.DBObject; import com.mongodb.gridfs.GridFSDBFile; import com.mongodb.gridfs.GridFSInputFile; import com.mongodb.util.JSON; import org.apache.camel.Exchange; import org.apache.camel.impl.DefaultProducer; public class GridFsProducer extends DefaultProducer { private GridFsEndpoint endpoint; public GridFsProducer(GridFsEndpoint endpoint) { super(endpoint); this.endpoint = endpoint; } public void process(Exchange exchange) throws Exception { String operation = endpoint.getOperation(); if (operation == null) { operation = exchange.getIn().getHeader(GridFsEndpoint.GRIDFS_OPERATION, String.class); } if (operation == null || "create".equals(operation)) { final String filename = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class); Long chunkSize = exchange.getIn().getHeader(GridFsEndpoint.GRIDFS_CHUNKSIZE, Long.class); InputStream ins = exchange.getIn().getMandatoryBody(InputStream.class); GridFSInputFile gfsFile = endpoint.getGridFs().createFile(ins, filename, true); if (chunkSize != null && chunkSize > 0) { gfsFile.setChunkSize(chunkSize); } final String ct = exchange.getIn().getHeader(Exchange.CONTENT_TYPE, String.class); if (ct != null) { gfsFile.setContentType(ct); } String metaData = exchange.getIn().getHeader(GridFsEndpoint.GRIDFS_METADATA, String.class); DBObject dbObject = (DBObject) JSON.parse(metaData); gfsFile.setMetaData(dbObject); gfsFile.save(); exchange.getIn().setHeader(Exchange.FILE_NAME_PRODUCED, gfsFile.getFilename()); } else if ("remove".equals(operation)) { final String filename = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class); endpoint.getGridFs().remove(filename); } else if ("findOne".equals(operation)) { final String filename = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class); GridFSDBFile file = endpoint.getGridFs().findOne(filename); if (file != null) { exchange.getIn().setHeader(GridFsEndpoint.GRIDFS_METADATA, JSON.serialize(file.getMetaData())); exchange.getIn().setHeader(Exchange.FILE_CONTENT_TYPE, file.getContentType()); exchange.getIn().setHeader(Exchange.FILE_LENGTH, file.getLength()); exchange.getIn().setHeader(Exchange.FILE_LAST_MODIFIED, file.getUploadDate()); exchange.getIn().setBody(file.getInputStream(), InputStream.class); } else { throw new FileNotFoundException("No GridFS file for " + filename); } } else if ("listAll".equals(operation)) { final String filename = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class); DBCursor cursor; if (filename == null) { cursor = endpoint.getGridFs().getFileList(); } else { cursor = endpoint.getGridFs().getFileList(new BasicDBObject("filename", filename)); } exchange.getIn().setBody(new DBCursorFilenameReader(cursor), Reader.class); } else if ("count".equals(operation)) { final String filename = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class); DBCursor cursor; if (filename == null) { cursor = endpoint.getGridFs().getFileList(); } else { cursor = endpoint.getGridFs().getFileList(new BasicDBObject("filename", filename)); } exchange.getIn().setBody(cursor.count(), Integer.class); } } private class DBCursorFilenameReader extends Reader { DBCursor cursor; StringBuilder current; int pos; DBCursorFilenameReader(DBCursor c) { cursor = c; current = new StringBuilder(4096); pos = 0; fill(); } void fill() { if (pos > 0) { current.delete(0, pos); pos = 0; } while (cursor.hasNext() && current.length() < 4000) { DBObject o = cursor.next(); current.append(o.get("filename")).append("\n"); } } @Override public int read(char[] cbuf, int off, int len) throws IOException { if (pos == current.length()) { fill(); } if (pos == current.length()) { return -1; } if (len > (current.length() - pos)) { len = current.length() - pos; } current.getChars(pos, pos + len, cbuf, off); pos += len; return len; } @Override public void close() throws IOException { cursor.close(); } } }