Java tutorial
/******************************************************************************* * Copyright 2017 Capital One Services, LLC and Bitwise, 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 hydrograph.ui.communication.utilities; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; import com.jcraft.jsch.Channel; import com.jcraft.jsch.ChannelExec; import com.jcraft.jsch.JSch; import com.jcraft.jsch.JSchException; import com.jcraft.jsch.Session; import com.jcraft.jsch.UserInfo; import hydrograph.ui.communication.messages.Message; import hydrograph.ui.communication.messages.MessageType; import hydrograph.ui.logging.factory.LogFactory; /** * The class SCPUtility * Provides utility methods to copy files using scp * * @author Bitwise * */ public class SCPUtility { private static final String STRICT_HOST_KEY_CHECKING_DEFAULT_VALUE = "no"; private static final String STRICT_HOST_KEY_CHECKING = "StrictHostKeyChecking"; private static final String PREFERRED_AUTHENTICATIONS_DEFAULT_VALUES = "publickey,keyboard-interactive,password"; private static final String PREFERRED_AUTHENTICATIONS = "PreferredAuthentications"; private static final int SSH_PORT = 22; private static final String GENERAL_SUCCESS_MESSAGE = "SUCCESS"; private static final String GENERAL_ERROR_MESSAGE = "ERROR"; private static final String AUTHENTICATION_FAILED_MESSAGE = "Invalid username or password"; private static final String AUTH_FAIL_EXCEPTION = "Auth fail"; private static final String UNKNOWN_HOST_MESSAGE = "Unknown host"; private static final String UNKNOWN_HOST_EXCEPTION = "UnknownHostException"; private static final Logger logger = LogFactory.INSTANCE.getLogger(SCPUtility.class); public static SCPUtility INSTANCE = new SCPUtility(); private SCPUtility() { } public Message validateCredentials(String host, String user, String password) { JSch jsch = new JSch(); Session session; try { session = jsch.getSession(user, host, SSH_PORT); session.setPassword(password); java.util.Properties config = new java.util.Properties(); config.put(STRICT_HOST_KEY_CHECKING, STRICT_HOST_KEY_CHECKING_DEFAULT_VALUE); session.setConfig(config); session.setConfig(PREFERRED_AUTHENTICATIONS, PREFERRED_AUTHENTICATIONS_DEFAULT_VALUES); session.connect(); session.disconnect(); } catch (Exception e) { return getErrorMessage(e); } return new Message(MessageType.SUCCESS, GENERAL_SUCCESS_MESSAGE); } private Message getErrorMessage(Exception e) { if (StringUtils.contains(e.getMessage(), UNKNOWN_HOST_EXCEPTION)) { return new Message(MessageType.UNKNOWN_HOST, UNKNOWN_HOST_MESSAGE); } else if (StringUtils.contains(e.getMessage(), AUTH_FAIL_EXCEPTION)) { return new Message(MessageType.INVALID_USERNAME_PASSWORD, AUTHENTICATION_FAILED_MESSAGE); } else { return new Message(MessageType.ERROR, GENERAL_ERROR_MESSAGE); } } /** * * Scp file from remote server * * @param host * @param user * @param password * @param remoteFile * @param localFile * @throws JSchException * @throws IOException */ public void scpFileFromRemoteServer(String host, String user, String password, String remoteFile, String localFile) throws JSchException, IOException { String prefix = null; if (new File(localFile).isDirectory()) { prefix = localFile + File.separator; } JSch jsch = new JSch(); Session session = jsch.getSession(user, host, 22); // username and password will be given via UserInfo interface. UserInfo userInfo = new UserInformation(password); session.setUserInfo(userInfo); session.connect(); // exec 'scp -f remoteFile' remotely String command = "scp -f " + remoteFile; Channel channel = session.openChannel("exec"); ((ChannelExec) channel).setCommand(command); // get I/O streams for remote scp OutputStream out = channel.getOutputStream(); InputStream in = channel.getInputStream(); channel.connect(); byte[] buf = new byte[1024]; // send '\0' buf[0] = 0; out.write(buf, 0, 1); out.flush(); readRemoteFileAndWriteToLocalFile(localFile, prefix, out, in, buf); session.disconnect(); } private void readRemoteFileAndWriteToLocalFile(String localFile, String prefix, OutputStream out, InputStream in, byte[] buf) throws IOException, FileNotFoundException { while (true) { int c = checkAck(in); if (c != 'C') { break; } // read '0644 ' in.read(buf, 0, 5); long filesize = 0L; while (true) { if (in.read(buf, 0, 1) < 0) { // error break; } if (buf[0] == ' ') break; filesize = filesize * 10L + (long) (buf[0] - '0'); } String file = null; for (int i = 0;; i++) { in.read(buf, i, 1); if (buf[i] == (byte) 0x0a) { file = new String(buf, 0, i); break; } } // send '\0' buf[0] = 0; out.write(buf, 0, 1); out.flush(); // read a content of local file try (FileOutputStream fos = new FileOutputStream(prefix == null ? localFile : prefix + file)) { int foo; while (true) { if (buf.length < filesize) foo = buf.length; else foo = (int) filesize; foo = in.read(buf, 0, foo); if (foo < 0) { // error break; } fos.write(buf, 0, foo); filesize -= foo; if (filesize == 0L) break; } } catch (IOException e) { throw e; } if (checkAck(in) != 0) { //System.exit(0); return; } // send '\0' buf[0] = 0; out.write(buf, 0, 1); out.flush(); } } private int checkAck(InputStream in) throws IOException { int b = in.read(); // b may be 0 for success, // 1 for error, // 2 for fatal error, // -1 if (b == 0) return b; if (b == -1) return b; if (b == 1 || b == 2) { StringBuffer sb = new StringBuffer(); int c; do { c = in.read(); sb.append((char) c); } while (c != '\n'); if (b == 1) { // error logger.debug(sb.toString()); } if (b == 2) { // fatal error logger.debug(sb.toString()); } } return b; } /** * * This class store user information who participates in scp * * @author Bitwise * */ private static class UserInformation implements UserInfo { String password; public UserInformation(String password) { this.password = password; } @Override public String getPassphrase() { return password; } @Override public String getPassword() { return this.password; } @Override public boolean promptPassphrase(String arg0) { return true; } @Override public boolean promptPassword(String arg0) { return true; } @Override public boolean promptYesNo(String arg0) { return true; } @Override public void showMessage(String arg0) { } } }