fileio.java

java web模拟的简单的一个网络硬盘

    int index = fileName.lastIndexOf(".");
    fileExt = fileName.substring(index, fileName.length());
    return fileExt;
  }

  /**
   * getRealFilePath(ServletContext context,String filePath)
   * 输入一个文件的相对路径，返回他的绝对路径，需要ServletContext信息
   * @param context ServletContext
   * @param filePath String
   * @return String
   */
  public static
      String getRealFilePath(ServletContext context, String filePath) {
    String realFilePath = context.getRealPath(filePath);
    return realFilePath;
  }

  /**
   * deleteFile(String filePath)
   * @param realFilePath String
   * @return boolean
   * 删除文件或目录
   */
  public static
      boolean deleteFile(String realFilePath) {
    File aFile = new File(realFilePath);    
    return aFile.delete();
  }

  /**
   * checkFilesFolder(String realFilePath)
   * 检查文件路径是否存在
   * @param realFilePath String
   * @return boolean
   */
  public static
      boolean checkFilesFolder(String realFilePath) {
    boolean flag = false;
    try {
      File aFile = new File(realFilePath);
      flag = aFile.exists();
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
    return flag;
  }

  /**
   * isAllowFile(String flag, String fileName)
   * 检查图形文件名是否合法--*.jpg;*.gif;*.gif
   * @param flag String
   * @param fileName String
   * @return boolean
   */
  public static
      boolean isAllowFile(String flag, String fileName) {
    boolean isAllow = false;
    if (flag.equals("pic")) {
      fileName = fileName.toLowerCase();
      if (fileName.endsWith(".jpg") || fileName.endsWith(".gif")
          || fileName.endsWith(".gif")) {
        isAllow = true;
      }
    }
    return isAllow;
  }

  /**
   * creatFile(InputStream stream, String outPutRealPath)
   * 以文件流的形式建立文件
   * @param stream InputStream
   * @param outPutRealPath String
   * @throws IOException
   * @return boolean
   */
  public static
      boolean creatFile(InputStream stream, String outPutRealPath) throws java.
      io.IOException {
    boolean flag = false;
    OutputStream bos = null;
    try {
      bos = new FileOutputStream(outPutRealPath);
      int bytesRead = 0;
      byte[] buffer = new byte[8192];
      while ( (bytesRead = stream.read(buffer, 0, 8192)) != -1) {
        bos.write(buffer, 0, bytesRead);
      }
      flag = true;
    }
    catch (Exception e) {
      System.out.println("建立文件出错！");
    }
    finally {
      stream.close();
      bos.close();
    }
    return flag;
  }

  /**
   * shrinkImage(String inRealPath, String outRealPath,
                                      int outWidth, int outHeigh)
   * 将图形文件按照指定最大宽高缩放，如果小于指定宽高，则拷贝
   * @param inRealPath String
   * @param outRealPath String
   * @param outWidth int
   * @param outHeigh int
   * @return boolean
   */
  public static boolean
      imageOperate(String inRealPath, String outRealPath,
                   int outWidth, int outHeigh) {
    boolean opFlag = false;
    try {
      File _file = new File(inRealPath); //读入文件
      Image src = javax.imageio.ImageIO.read(_file); //构造Image对象
      int width = src.getWidth(null); //得到源图宽
      int height = src.getHeight(null); //得到源图长
      int newWidth = 1;
      int newHeight = 1;
      //根据源长宽缩放
      if (width < outWidth && height < outHeigh) {
        //拷贝原图
        copyFile(new File(inRealPath), new File(outRealPath));
      }
      else {
        if (width >= height) {
          newWidth = outWidth;
          newHeight = outWidth * height / width;
        }
        else {
          newHeight = outHeigh;
          newWidth = outHeigh * width / height;
        }
        //绘制缩小后的图
        BufferedImage tag = new BufferedImage(newWidth, newHeight,
                                              BufferedImage.TYPE_INT_RGB);
        tag.getGraphics().drawImage(src, 0, 0, newWidth, newHeight, null);
        //输出到文件流
        FileOutputStream out = new FileOutputStream(outRealPath);
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        //近JPEG编码
        encoder.encode(tag);
        out.close();
      }
      opFlag = true;
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
    return opFlag;
  }

  /**
   * getDirectoryFilesNum(String realPath)
   * 获得一个目录下的文件数量
   * @param realPath String
   * @return int
   */
  public static int getDirectoryFilesNum(String realPath) {
    int filesNum = 0;
    if (checkFilesFolder(realPath)) {
      File directory = new File(realPath);
      if (directory.isDirectory()) {
        File[] entries = directory.listFiles();
        filesNum = entries.length;
      }
    }
    return filesNum;
  }

  /**
   * getDirectoryFilesName(String realPath)
   * 获得该目录下所有文件名字（包含扩展名）
   * @param realPath String
   * @return Vector
   */
  @SuppressWarnings("unchecked")
public static Vector getDirectoryFilesName(String realPath) {
    Vector theVector = new Vector();
    if (checkFilesFolder(realPath)) {
      File directory = new File(realPath);
      if (directory.isDirectory()) {
        File[] entries = directory.listFiles();
        for (int i = 0; i < entries.length; i++) {
          if (entries[i].getAbsolutePath().indexOf(".") > 0) {
            theVector.add(entries[i].getAbsolutePath().substring(entries[i].
                getAbsolutePath().lastIndexOf(File.separator) + 1));
          }
        }
      }
    }
    return theVector;
  }

  /**
   * getSubDirsName(String realPath)
   * 获得该目录下所有子目录
   * @param realPath String
   * @return Vector
   */
  @SuppressWarnings("unchecked")
public static Vector getSubDirsName(String realPath) {
    Vector theVector = new Vector();
    if (checkFilesFolder(realPath)) {
      File directory = new File(realPath);
      if (directory.isDirectory()) {
        File[] entries = directory.listFiles();
        for (int i = 0; i < entries.length; i++) {
          if (entries[i].getAbsolutePath().indexOf(".") < 0) {
            theVector.add(entries[i].getAbsolutePath().substring(entries[i].
                getAbsolutePath().lastIndexOf(File.separator) + 1));
          }
        }
      }
    }
    return theVector;
  }

  /**
   * smartMakeDir(ServletContext context,String filePath)
   * 输入context、相对路径建立目录
   * @param context ServletContext
   * @param filePath String
   * @return int 建立目录的数量 -1错误无法建立目录
   */
  public static int smartMakeDir(ServletContext context, String filePath) {
    int opFlag = 0;
    //分解路径
    String[] tempPath = filePath.substring(1).split("/");
    String tempStr = "";
    String realPath;
    for (int i = 0; i < tempPath.length; i++) {
      //检查该路径是否存在，不存在就建立
      tempStr += "/" + tempPath[i];
      realPath = getRealFilePath(context, tempStr);
      if (!checkFilesFolder(realPath)) {
        if (makeDir(realPath)) {
          ++opFlag;
        }
        else {
          opFlag = -1;
          break;
        }
      }
    }
    return opFlag;
  }

  /**
   * String makeDirName(int buildID)
   * 根据任意ID对23,19,17取模生成目录名,从而生成相应的目录结构;
   * @param buildID int
   * @return String
   */
  public static String makeDirName(int buildID) {
    int dirID = buildID;
    StringBuffer dirStructure = new StringBuffer();
    dirStructure.append("/").append(String.valueOf(dirID % 23));
    dirStructure.append("/").append(String.valueOf(dirID % 19));
    dirStructure.append("/").append(String.valueOf(dirID % 17));
    return dirStructure.toString();
  }

  /**
   * getDirectoryAllFiles(String realPath)
   * @param realpath String
   * @return AarrayList
   * @todo get all files in the realPath
   */
  @SuppressWarnings("unchecked")
public static ArrayList getDirectoryAllFiles(String realPath) {
    ArrayList fileList = new ArrayList();
    if (checkFilesFolder(realPath)) {
      File directory = new File(realPath);
      if (directory.isDirectory()) {
        File[] entries = directory.listFiles();
        for (int i = 0; i < entries.length; i++) {
          if (entries[i].getAbsolutePath().indexOf(".") > 0) {
            fileList.add(entries[i].getAbsolutePath());
          }
        }
      }
    }
    return fileList;
  }

  /**
   * getAllSubDirs(String realPath)
   * @param realPath String
   * @return ArrayList
   * @todo get all directories in the realPath
   */
  @SuppressWarnings("unchecked")
public static ArrayList getAllSubDirs(String realPath) {
    ArrayList dirList = new ArrayList();
    if (checkFilesFolder(realPath)) {
      File directory = new File(realPath);
      if (directory.isDirectory()) {
        File[] entries = directory.listFiles();
        for (int i = 0; i < entries.length; i++) {
          if (entries[i].getAbsolutePath().indexOf(".") < 0) {
            dirList.add(entries[i].getAbsolutePath());
          }
        }
      }
    }
    return dirList;
  }

  /**
   * createImgWaterMark(String filePath, String watermark)
   * 在图片上打上水印
   * @param filePath String
   * @param watermark String
   * @return ArrayList
   */
  public static boolean createImgWaterMark(String filePath, String watermark) {
    try {
      File _file = new File(filePath); //读入文件
      Image theImg = javax.imageio.ImageIO.read(_file); //构造Image对象
      ImageIcon waterIcon = new ImageIcon("temp");
      Image waterImg = waterIcon.getImage();
      int width = theImg.getWidth(null);
      int height = theImg.getHeight(null);
      BufferedImage bimage = new BufferedImage(width, height,
                                               BufferedImage.TYPE_INT_RGB);
      Graphics2D g = bimage.createGraphics();
      g.setColor(Color.red);
      g.setBackground(Color.white);
      g.drawImage(theImg, 0, 0, null);
      g.drawImage(waterImg, 100, 100, null);
      g.drawString(watermark, 10, 10); //添加文字
      g.dispose();
      FileOutputStream out = new FileOutputStream(filePath);
      JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
      JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bimage);
      param.setQuality(50f, true);
      encoder.encode(bimage, param);
      out.close();
    }
    catch (Exception e) {
      System.out.println(e.getMessage());
      return false;
    }
    return true;
  }
}