tain.kr.test.vfs.v01.Shell.java Source code

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/**
 * Copyright 2014, 2015, 2016, 2017 TAIN, Inc. all rights reserved.
 *
 * Licensed under the GNU GENERAL PUBLIC LICENSE, Version 3, 29 June 2007 (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.gnu.org/licenses/
 *
 * 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.
 *
 * -----------------------------------------------------------------
 * Copyright 2014, 2015, 2016, 2017 TAIN, Inc.
 *
 */
package tain.kr.test.vfs.v01;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.StringTokenizer;

import org.apache.commons.vfs2.Capability;
import org.apache.commons.vfs2.FileContent;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemManager;
import org.apache.commons.vfs2.FileType;
import org.apache.commons.vfs2.FileUtil;
import org.apache.commons.vfs2.Selectors;
import org.apache.commons.vfs2.VFS;
import org.apache.commons.vfs2.operations.FileOperationProvider;
import org.apache.log4j.Logger;

/**
 * Code Templates > Comments > Types
 *
 * <PRE>
 *   -. FileName   : Shell.java
 *   -. Package    : tain.kr.test.vfs.v01
 *   -. Comment    :
 *   -. Author     : taincokr
 *   -. First Date : 2017. 4. 12. {time}
 * </PRE>
 *
 * @author taincokr
 *
 */
public final class Shell {

    private static boolean flag = true;

    private static final Logger log = Logger.getLogger(Shell.class);

    ///////////////////////////////////////////////////////////////////////////////////////////////

    private final FileSystemManager mgr;
    private FileObject cwd;
    private final BufferedReader reader;

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /*
     * constructor
     */
    private Shell() throws IOException {

        this.mgr = VFS.getManager();
        this.cwd = mgr.toFileObject(new File(System.getProperty("user.dir")));
        this.reader = new BufferedReader(new InputStreamReader(System.in, Charset.defaultCharset()));

        if (flag) {
            log.debug(">>>>> in class " + this.getClass().getSimpleName());
            log.debug(">>>>> user.dir = " + System.getProperty("user.dir"));
        }
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    private void go() throws Exception {

        System.out.println("VFS Shell " + getVersion(Shell.class));
        while (true) {
            final String[] cmd = nextCommand();
            if (cmd == null) {
                return;
            }

            if (cmd.length == 0) {
                continue;
            }

            final String cmdName = cmd[0];
            if (cmdName.equalsIgnoreCase("exit") || cmdName.equalsIgnoreCase("quit")) {
                return;
            }

            try {
                handleCommand(cmd);
            } catch (final Exception e) {
                System.err.println("Command failed:");
                e.printStackTrace(System.err);
            }
        }
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Handles a command.
     */
    private void handleCommand(final String[] cmd) throws Exception {

        final String cmdName = cmd[0];

        if (cmdName.equalsIgnoreCase("cat")) {
            cat(cmd);
        } else if (cmdName.equalsIgnoreCase("cd")) {
            cd(cmd);
        } else if (cmdName.equalsIgnoreCase("cp")) {
            cp(cmd);
        } else if (cmdName.equalsIgnoreCase("help") || cmdName.equals("?")) {
            help();
        } else if (cmdName.equalsIgnoreCase("ls")) {
            ls(cmd);
        } else if (cmdName.equalsIgnoreCase("pwd")) {
            pwd();
        } else if (cmdName.equalsIgnoreCase("rm")) {
            rm(cmd);
        } else if (cmdName.equalsIgnoreCase("touch")) {
            touch(cmd);
        } else if (cmdName.equalsIgnoreCase("info")) {
            info(cmd);
        } else {
            System.err.println("Unknown command \"" + cmdName + "\" (Try 'help').");
        }
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    private void info(String[] cmd) throws Exception {

        if (cmd.length > 1) {
            info(cmd[1]);
        } else {
            System.out.println("Default manager: \"" + mgr.getClass().getName() + "\" " + "version "
                    + getVersion(mgr.getClass()));

            String[] schemes = mgr.getSchemes();
            List<String> virtual = new ArrayList<String>();
            List<String> physical = new ArrayList<String>();

            for (int i = 0; i < schemes.length; i++) {
                Collection<Capability> caps = mgr.getProviderCapabilities(schemes[i]);
                if (caps != null) {
                    if (caps.contains(Capability.VIRTUAL) || caps.contains(Capability.COMPRESS)
                            || caps.contains(Capability.DISPATCHER)) {
                        virtual.add(schemes[i]);
                    } else {
                        physical.add(schemes[i]);
                    }
                }
            }

            if (!physical.isEmpty()) {
                System.out.println("  Provider Schemes: " + physical);
            }

            if (!virtual.isEmpty()) {
                System.out.println("   Virtual Schemes: " + virtual);
            }
        }
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    private void info(String scheme) throws Exception {

        System.out.println("Provider Info for scheme \"" + scheme + "\":");
        Collection<Capability> caps;
        caps = mgr.getProviderCapabilities(scheme);

        if (caps != null && !caps.isEmpty()) {
            System.out.println("  capabilities: " + caps);
        }

        FileOperationProvider[] ops = mgr.getOperationProviders(scheme);
        if (ops != null && ops.length > 0) {
            System.out.println("  operations: " + ops);
        }
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Does a 'help' command.
     */
    private void help() {

        System.out.println("Commands:");
        System.out.println("cat <file>         Displays the contents of a file.");
        System.out.println("cd [folder]        Changes current folder.");
        System.out.println("cp <src> <dest>    Copies a file or folder.");
        System.out.println("help               Shows this message.");
        System.out.println("info [scheme]      Displays information about providers.");
        System.out.println("ls [-R] [path]     Lists contents of a file or folder.");
        System.out.println("pwd                Displays current folder.");
        System.out.println("rm <path>          Deletes a file or folder.");
        System.out.println("touch <path>       Sets the last-modified time of a file.");
        System.out.println("exit, quit         Exits this program.");
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Does an 'rm' command.
     */
    private void rm(final String[] cmd) throws Exception {

        if (cmd.length < 2) {
            throw new Exception("USAGE: rm <path>");
        }

        final FileObject file = mgr.resolveFile(cwd, cmd[1]);
        file.delete(Selectors.SELECT_SELF);
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Does a 'cp' command.
     */
    private void cp(final String[] cmd) throws Exception {

        if (cmd.length < 3) {
            throw new Exception("USAGE: cp <src> <dest>");
        }

        final FileObject src = mgr.resolveFile(cwd, cmd[1]);
        FileObject dest = mgr.resolveFile(cwd, cmd[2]);

        if (dest.exists() && dest.getType() == FileType.FOLDER) {
            dest = dest.resolveFile(src.getName().getBaseName());
        }

        dest.copyFrom(src, Selectors.SELECT_ALL);
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Does a 'cat' command.
     */
    private void cat(final String[] cmd) throws Exception {

        if (cmd.length < 2) {
            throw new Exception("USAGE: cat <path>");
        }

        // Locate the file
        final FileObject file = mgr.resolveFile(cwd, cmd[1]);

        // Dump the contents to System.out
        FileUtil.writeContent(file, System.out);
        System.out.println();
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Does a 'pwd' command.
     */
    private void pwd() {
        System.out.println("Current folder is " + cwd.getName());
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Does a 'cd' command.
     * If the taget directory does not exist, a message is printed to <code>System.err</code>.
     */
    private void cd(final String[] cmd) throws Exception {

        final String path;
        if (cmd.length > 1) {
            path = cmd[1];
        } else {
            path = System.getProperty("user.home");
        }

        // Locate and validate the folder
        final FileObject tmp = mgr.resolveFile(cwd, path);
        if (tmp.exists()) {
            cwd = tmp;
        } else {
            System.out.println("Folder does not exist: " + tmp.getName());
        }
        System.out.println("Current folder is " + cwd.getName());
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Does an 'ls' command.
     */
    private void ls(final String[] cmd) throws FileSystemException {

        int pos = 1;
        final boolean recursive;

        if (cmd.length > pos && cmd[pos].equals("-R")) {
            recursive = true;
            pos++;
        } else {
            recursive = false;
        }

        final FileObject file;
        if (cmd.length > pos) {
            file = mgr.resolveFile(cwd, cmd[pos]);
        } else {
            file = cwd;
        }

        if (file.getType() == FileType.FOLDER) {
            // List the contents
            System.out.println("Contents of " + file.getName());
            listChildren(file, recursive, "");
        } else {
            // Stat the file
            System.out.println(file.getName());
            final FileContent content = file.getContent();
            System.out.println("Size: " + content.getSize() + " bytes.");
            final DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);
            final String lastMod = dateFormat.format(new Date(content.getLastModifiedTime()));
            System.out.println("Last modified: " + lastMod);
        }
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Does a 'touch' command.
     */
    private void touch(final String[] cmd) throws Exception {

        if (cmd.length < 2) {
            throw new Exception("USAGE: touch <path>");
        }

        final FileObject file = mgr.resolveFile(cwd, cmd[1]);

        if (!file.exists()) {
            file.createFile();
        }
        file.getContent().setLastModifiedTime(System.currentTimeMillis());
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Lists the children of a folder.
     */
    private void listChildren(final FileObject dir, final boolean recursive, final String prefix)
            throws FileSystemException {

        final FileObject[] children = dir.getChildren();
        for (final FileObject child : children) {
            System.out.print(prefix);
            System.out.print(child.getName().getBaseName());

            if (child.getType() == FileType.FOLDER) {

                System.out.println("/");
                if (recursive) {
                    listChildren(child, recursive, prefix + "    ");
                }
            } else {
                System.out.println();
            }
        }
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * Returns the next command, split into tokens.
     */
    private String[] nextCommand() throws IOException {

        System.out.print("> ");
        final String line = reader.readLine();

        if (line == null) {
            return null;
        }

        final ArrayList<String> cmd = new ArrayList<String>();
        final StringTokenizer tokens = new StringTokenizer(line);

        while (tokens.hasMoreTokens()) {
            cmd.add(tokens.nextToken());
        }

        return cmd.toArray(new String[cmd.size()]);
    }

    ///////////////////////////////////////////////////////////////////////////////////////////////

    private static String getVersion(Class<?> cls) {

        try {
            return cls.getPackage().getImplementationVersion();
        } catch (Exception ignored) {
            return "N/A";
        }
    }

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    /*
     * static test method
     */
    private static void test01(String[] args) throws Exception {

        if (flag) {
            /*
             * begin
             */
            new Shell().go();
        }
    }

    /*
     * main method
     */
    public static void main(String[] args) throws Exception {

        if (flag)
            log.debug(">>>>> " + new Object() {
            }.getClass().getEnclosingClass().getName());

        if (flag)
            test01(args);
    }
}