Java tutorial
/* * Copyright 2002-2012 the original author or authors. * * 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 org.springframework.integration.sftp.session; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.ArrayList; import java.util.List; import java.util.Vector; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.core.NestedIOException; import org.springframework.integration.file.remote.session.Session; import org.springframework.util.Assert; import org.springframework.util.FileCopyUtils; import com.jcraft.jsch.ChannelSftp; import com.jcraft.jsch.ChannelSftp.LsEntry; import com.jcraft.jsch.JSchException; import com.jcraft.jsch.SftpATTRS; import com.jcraft.jsch.SftpException; /** * Default SFTP {@link Session} implementation. Wraps a JSCH session instance. * * @author Josh Long * @author Mario Gray * @author Mark Fisher * @author Oleg Zhurakousky * @author Gary Russell * @since 2.0 */ class SftpSession implements Session<LsEntry> { private final Log logger = LogFactory.getLog(this.getClass()); private final com.jcraft.jsch.Session jschSession; private volatile ChannelSftp channel; public SftpSession(com.jcraft.jsch.Session jschSession) { Assert.notNull(jschSession, "jschSession must not be null"); this.jschSession = jschSession; } public boolean remove(String path) throws IOException { Assert.state(this.channel != null, "session is not connected"); try { this.channel.rm(path); return true; } catch (SftpException e) { throw new NestedIOException("Failed to remove file: " + e); } } public LsEntry[] list(String path) throws IOException { Assert.state(this.channel != null, "session is not connected"); try { Vector<?> lsEntries = this.channel.ls(path); if (lsEntries != null) { LsEntry[] entries = new LsEntry[lsEntries.size()]; for (int i = 0; i < lsEntries.size(); i++) { Object next = lsEntries.get(i); Assert.state(next instanceof LsEntry, "expected only LsEntry instances from channel.ls()"); entries[i] = (LsEntry) next; } return entries; } } catch (SftpException e) { throw new NestedIOException("Failed to list files", e); } return new LsEntry[0]; } public String[] listNames(String path) throws IOException { LsEntry[] entries = this.list(path); List<String> names = new ArrayList<String>(); for (int i = 0; i < entries.length; i++) { String fileName = entries[i].getFilename(); SftpATTRS attrs = entries[i].getAttrs(); if (!attrs.isDir() && !attrs.isLink()) { names.add(fileName); } } String[] fileNames = new String[names.size()]; return names.toArray(fileNames); } public void read(String source, OutputStream os) throws IOException { Assert.state(this.channel != null, "session is not connected"); try { InputStream is = this.channel.get(source); FileCopyUtils.copy(is, os); } catch (SftpException e) { throw new NestedIOException("failed to read file", e); } } public void write(InputStream inputStream, String destination) throws IOException { Assert.state(this.channel != null, "session is not connected"); try { this.channel.put(inputStream, destination); } catch (SftpException e) { throw new NestedIOException("failed to write file", e); } } public void close() { if (this.jschSession.isConnected()) { this.jschSession.disconnect(); } } public boolean isOpen() { return this.jschSession.isConnected(); } public void rename(String pathFrom, String pathTo) throws IOException { try { this.channel.rename(pathFrom, pathTo); } catch (SftpException sftpex) { if (logger.isDebugEnabled()) { logger.debug( "Initial File rename failed, possibly because file already exists. Will attempt to delete file: " + pathTo + " and execute rename again."); } try { this.remove(pathTo); if (logger.isDebugEnabled()) { logger.debug("Delete file: " + pathTo + " succeeded. Will attempt rename again"); } } catch (IOException ioex) { throw new NestedIOException("Failed to delete file " + pathTo, ioex); } try { // attempt to rename again this.channel.rename(pathFrom, pathTo); } catch (SftpException sftpex2) { throw new NestedIOException("failed to rename from " + pathFrom + " to " + pathTo, sftpex2); } } if (logger.isDebugEnabled()) { logger.debug("File: " + pathFrom + " was successfully renamed to " + pathTo); } } public boolean mkdir(String remoteDirectory) throws IOException { try { this.channel.mkdir(remoteDirectory); } catch (SftpException e) { throw new NestedIOException("failed to create remote directory '" + remoteDirectory + "'.", e); } return true; } public boolean exists(String path) { try { this.channel.lstat(path); return true; } catch (SftpException e) { // ignore } return false; } void connect() { try { if (!this.jschSession.isConnected()) { this.jschSession.connect(); this.channel = (ChannelSftp) this.jschSession.openChannel("sftp"); } if (this.channel != null && !this.channel.isConnected()) { this.channel.connect(); } } catch (JSchException e) { throw new IllegalStateException("failed to connect", e); } } }