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.sshd.server.command; import java.io.ByteArrayOutputStream; import java.io.EOFException; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.Arrays; import org.apache.sshd.common.util.DirectoryScanner; import org.apache.sshd.common.util.SelectorUtils; import org.apache.sshd.server.Command; import org.apache.sshd.server.CommandFactory; import org.apache.sshd.server.Environment; import org.apache.sshd.server.ExitCallback; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * This commands provide SCP support on both server and client side. * Permissions and preservation of access / modification times on files * are not supported. * * @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a> */ public class ScpCommand implements Command, Runnable { protected static final Log log = LogFactory.getLog(ScpCommand.class); protected static final int OK = 0; protected static final int WARNING = 1; protected static final int ERROR = 2; protected String name; protected boolean optR; protected boolean optT; protected boolean optF; protected boolean optV; protected boolean optD; protected boolean optP; protected String root; protected InputStream in; protected OutputStream out; protected OutputStream err; protected ExitCallback callback; protected IOException error; public ScpCommand(String[] args) { name = Arrays.asList(args).toString(); if (log.isDebugEnabled()) { log.debug("Executing command " + name); } root = "."; for (int i = 1; i < args.length; i++) { if (args[i].charAt(0) == '-') { for (int j = 1; j < args[i].length(); j++) { switch (args[i].charAt(j)) { case 'f': optF = true; break; case 'p': optP = true; break; case 'r': optR = true; break; case 't': optT = true; break; case 'v': optV = true; break; case 'd': optD = true; break; // default: // error = new IOException("Unsupported option: " + args[i].charAt(j)); // return; } } } else if (i == args.length - 1) { root = args[args.length - 1]; } } if (!optF && !optT) { error = new IOException("Either -f or -t option should be set"); } } public void setInputStream(InputStream in) { this.in = in; } public void setOutputStream(OutputStream out) { this.out = out; } public void setErrorStream(OutputStream err) { this.err = err; } public void setExitCallback(ExitCallback callback) { this.callback = callback; } public void start(Environment env) throws IOException { if (error != null) { throw error; } new Thread(this, "ScpCommand: " + name).start(); } public void destroy() { } public void run() { int exitValue = OK; String exitMessage = null; try { if (optT) { ack(); for (;;) { String line; boolean isDir = false; int c = readAck(true); switch (c) { case -1: return; case 'D': isDir = true; case 'C': case 'E': line = ((char) c) + readLine(); break; default: //a real ack that has been acted upon already continue; } if (optR && isDir) { writeDir(line, new File(root)); } else { writeFile(line, new File(root)); } } } else if (optF) { String pattern = root; int idx = pattern.indexOf('*'); if (idx >= 0) { String basedir = ""; int lastSep = pattern.substring(0, idx).lastIndexOf('/'); if (lastSep >= 0) { basedir = pattern.substring(0, lastSep); pattern = pattern.substring(lastSep + 1); } String[] included = new DirectoryScanner(basedir, pattern).scan(); for (String path : included) { File file = new File(basedir, path); if (file.isFile()) { readFile(file); } else if (file.isDirectory()) { if (!optR) { out.write(WARNING); out.write((path + " not a regular file\n").getBytes()); } else { readDir(file); } } else { out.write(WARNING); out.write((path + " unknown file type\n").getBytes()); } } } else { String basedir = ""; int lastSep = pattern.lastIndexOf('/'); if (lastSep >= 0) { basedir = pattern.substring(0, lastSep); pattern = pattern.substring(lastSep + 1); } File file = new File(basedir, pattern); if (!file.exists()) { throw new IOException(file + ": no such file or directory"); } if (file.isFile()) { readFile(file); } else if (file.isDirectory()) { if (!optR) { throw new IOException(file + " not a regular file"); } else { readDir(file); } } else { throw new IOException(file + ": unknown file type"); } } } else { throw new IOException("Unsupported mode"); } } catch (IOException e) { try { exitValue = ERROR; exitMessage = e.getMessage(); out.write(exitValue); out.write(exitMessage.getBytes()); out.write('\n'); out.flush(); } catch (IOException e2) { // Ignore } log.info("Error in scp command", e); } finally { if (callback != null) { callback.onExit(exitValue, exitMessage); } } } protected void writeDir(String header, File path) throws IOException { if (log.isDebugEnabled()) { log.debug("Writing dir " + path); } if (!header.startsWith("D")) { throw new IOException("Expected a D message but got '" + header + "'"); } String perms = header.substring(1, 5); int length = Integer.parseInt(header.substring(6, header.indexOf(' ', 6))); String name = header.substring(header.indexOf(' ', 6) + 1); if (length != 0) { throw new IOException("Expected 0 length for directory but got " + length); } File file; if (path.exists() && path.isDirectory()) { file = new File(path, name); } else if (!path.exists() && path.getParentFile().exists() && path.getParentFile().isDirectory()) { file = path; } else { throw new IOException("Can not write to " + path); } if (!(file.exists() && file.isDirectory()) && !file.mkdir()) { throw new IOException("Could not create directory " + file); } ack(); for (;;) { header = readLine(); if (header.startsWith("C")) { writeFile(header, file); } else if (header.startsWith("D")) { writeDir(header, file); } else if (header.equals("E")) { ack(); break; } else { throw new IOException("Unexpected message: '" + header + "'"); } } } protected void writeFile(String header, File path) throws IOException { if (log.isDebugEnabled()) { log.debug("Writing file " + path); } if (!header.startsWith("C")) { throw new IOException("Expected a C message but got '" + header + "'"); } String perms = header.substring(1, 5); long length = Long.parseLong(header.substring(6, header.indexOf(' ', 6))); String name = header.substring(header.indexOf(' ', 6) + 1); File file; if (path.exists() && path.isDirectory()) { file = new File(path, name); } else if (path.exists() && path.isFile()) { file = path; } else if (!path.exists() && path.getParentFile().exists() && path.getParentFile().isDirectory()) { file = path; } else { throw new IOException("Can not write to " + path); } if (file.exists() && file.isDirectory()) { throw new IOException("File is a directory: " + file); } else if (file.exists() && !file.canWrite()) { throw new IOException("Can not write to file: " + file); } OutputStream os = new FileOutputStream(file); try { ack(); byte[] buffer = new byte[8192]; while (length > 0) { int len = (int) Math.min(length, buffer.length); len = in.read(buffer, 0, len); if (len <= 0) { throw new IOException("End of stream reached"); } os.write(buffer, 0, len); length -= len; } } finally { os.close(); } ack(); readAck(false); } protected String readLine() throws IOException { ByteArrayOutputStream baos = new ByteArrayOutputStream(); for (;;) { int c = in.read(); if (c == '\n') { return baos.toString(); } else if (c == -1) { throw new IOException("End of stream"); } else { baos.write(c); } } } protected void readFile(File path) throws IOException { if (log.isDebugEnabled()) { log.debug("Reading file " + path); } StringBuffer buf = new StringBuffer(); buf.append("C"); buf.append("0644"); // what about perms buf.append(" "); buf.append(path.length()); // length buf.append(" "); buf.append(path.getName()); buf.append("\n"); out.write(buf.toString().getBytes()); out.flush(); readAck(false); InputStream is = new FileInputStream(path); try { byte[] buffer = new byte[8192]; for (;;) { int len = is.read(buffer, 0, buffer.length); if (len == -1) { break; } out.write(buffer, 0, len); } } finally { is.close(); } ack(); readAck(false); } protected void readDir(File path) throws IOException { if (log.isDebugEnabled()) { log.debug("Reading directory " + path); } StringBuffer buf = new StringBuffer(); buf.append("D"); buf.append("0755"); // what about perms buf.append(" "); buf.append("0"); // length buf.append(" "); buf.append(path.getName()); buf.append("\n"); out.write(buf.toString().getBytes()); out.flush(); readAck(false); for (File child : path.listFiles()) { if (child.isFile()) { readFile(child); } else if (child.isDirectory()) { readDir(child); } } out.write("E\n".getBytes()); out.flush(); readAck(false); } protected void ack() throws IOException { out.write(0); out.flush(); } protected int readAck(boolean canEof) throws IOException { int c = in.read(); switch (c) { case -1: if (!canEof) { throw new EOFException(); } break; case OK: break; case WARNING: log.warn("Received warning: " + readLine()); break; case ERROR: throw new IOException("Received nack: " + readLine()); default: break; } return c; } }