package com.mozilla.bespin;import org.apache.commons.io.FileUtils;import java.io.File;import java.io.FileNotFoundException;import java.io.FileInputStream;import java.io.IOException;import java.io.FileOutputStream;import java.util.List;import java.util.Map;import java.util.HashMap;import java.util.ArrayList;import java.nio.charset.Charset;/** * Abstraction for file I/O. */public class FileSystem {    private File base;    private File template;    public FileSystem(File base, File template) {        this.base = base;        this.template = template;    }    /**     *     * @param path relative to the base directory     * @return     */    public File[] list(UserSession session, String path) {        return new File(getUserHome(session), path).listFiles();    }    /**     * Returns a file as a String.     *     * @param path     * @param session the user requesting the file     * @return     * @throws FileNotFoundException     */    public String read(UserSession session, String path) throws FileNotFoundException {        File file = getFileHandle(session, path);        if (file.isDirectory()) throw new FileNotFoundException(String.format("Passed file %1$s is a directory not a file", file));        if (!file.exists()) throw new FileNotFoundException(String.format("Passed file %1$s does not exist", file));        try {            FileInputStream in = new FileInputStream(file);            byte[] bytes = new byte[(int) file.length()];            in.read(bytes);            in.close();            return new String(bytes, Charset.forName("UTF-8"));        } catch (IOException e) {            System.err.println("Obscure I/O error encountered (stack trace to follow)");            e.printStackTrace();            return "IO ERROR";        }    }    public void write(UserSession session, String path, String contents) throws IOException {        File file = getFileHandle(session, path);        if (file.isDirectory()) throw new FileNotFoundException(String.format("Passed file %1$s is a directory not a file", file));        if (!file.exists()) file.getParentFile().mkdirs();                byte[] bytes = contents.getBytes(Charset.forName("UTF-8"));        FileOutputStream out = new FileOutputStream(file);        out.write(bytes);        out.close();    }    public void delete(UserSession session, String path) throws FileNotFoundException {        File file = getFileHandle(session, path);        if (file.equals(base)) return;        if (file.isDirectory()) return; // TODO: implement this        if (file.exists()) {            file.delete();        }    }    public File getFileHandle(UserSession session, String path) throws FileNotFoundException {        return new File(getUserHome(session), path);    }    public File getUserHome(UserSession session) {        File userHome = new File(base, session.username);        if (userHome.exists()) {            userHome.mkdirs();            // try to copy the template directory to the newly-created user home directory            try {                FileUtils.copyDirectory(template, userHome);            } catch (IOException e) {                System.err.println(String.format("Couldn't copy template \"%1$s\" directory to new user directory \"%2$s\"; stacktrace follows", template, userHome));                e.printStackTrace();            }        }        return userHome;    }}