Class IOUtils


  • public class IOUtils
    extends Object
    The IOUtils provide some IO related helper methods.
    Author:
    Thomas Morgner.
    • Method Detail

      • getInstance

        public static IOUtils getInstance()
        Gets the singleton instance of the utility package.
        Returns:
        the singleton instance.
      • createRelativePath

        public String createRelativePath​(String targetFile,
                                         String baseFile)
        Creates a relative url by stripping the common parts of the the url. If the baseFile denotes a directory, it must end with a slash.
        Parameters:
        targetFile - the to be stripped url
        baseFile - the base url, to which the url is relative to.
        Returns:
        the relative url, or the url unchanged, if there is no relation beween both URLs.
      • createRelativeURL

        public String createRelativeURL​(URL url,
                                        URL baseURL)
        Creates a relative url by stripping the common parts of the the url. If the base-URL denotes a directory, it must end with a slash.
        Parameters:
        url - the to be stripped url
        baseURL - the base url, to which the url is relative to.
        Returns:
        the relative url, or the url unchanged, if there is no relation beween both URLs.
      • copyStreams

        public void copyStreams​(InputStream in,
                                OutputStream out)
                         throws IOException
        Copies the InputStream into the OutputStream, until the end of the stream has been reached. This method uses a buffer of 4096 kbyte.
        Parameters:
        in - the inputstream from which to read.
        out - the outputstream where the data is written to.
        Throws:
        IOException - if a IOError occurs.
      • copyStreams

        public void copyStreams​(InputStream in,
                                OutputStream out,
                                int buffersize)
                         throws IOException
        Copies the InputStream into the OutputStream, until the end of the stream has been reached.
        Parameters:
        in - the inputstream from which to read.
        out - the outputstream where the data is written to.
        buffersize - the buffer size.
        Throws:
        IOException - if a IOError occurs.
      • copyWriter

        public void copyWriter​(Reader in,
                               Writer out)
                        throws IOException
        Copies the contents of the Reader into the Writer, until the end of the stream has been reached. This method uses a buffer of 4096 kbyte.
        Parameters:
        in - the reader from which to read.
        out - the writer where the data is written to.
        Throws:
        IOException - if a IOError occurs.
      • copyWriter

        public void copyWriter​(Reader in,
                               Writer out,
                               int buffersize)
                        throws IOException
        Copies the contents of the Reader into the Writer, until the end of the stream has been reached.
        Parameters:
        in - the reader from which to read.
        out - the writer where the data is written to.
        buffersize - the buffer size.
        Throws:
        IOException - if a IOError occurs.
      • readFully

        public void readFully​(InputStream in,
                              byte[] data,
                              int offset,
                              int length)
                       throws IOException
        Reads the given number of bytes into the target array. This method does not return until all bytes are read. In case a end-of-stream is reached, the method throws an Exception.
        Parameters:
        in - the inputstream from where to read.
        data - the array where to store the data.
        offset - the offset in the array where to store the data.
        length - the number of bytes to be read.
        Throws:
        IOException - if an IO error occured or the End of the stream has been reached.
      • readSafely

        public int readSafely​(InputStream in,
                              byte[] data,
                              int offset,
                              int length)
                       throws IOException
        Reads the given number of bytes into the target array. This method does not return until all bytes are read. In case a end-of-stream is reached, the method throws an Exception.
        Parameters:
        in - the inputstream from where to read.
        data - the array where to store the data.
        offset - the offset in the array where to store the data.
        length - the number of bytes to be read.
        Throws:
        IOException - if an IO error occured or the End of the stream has been reached.
      • getFileName

        public String getFileName​(URL url)
        Extracts the file name from the URL.
        Parameters:
        url - the url.
        Returns:
        the extracted filename.
      • getFileName

        public String getFileName​(String path)
        Extracts the last file name from the given pathname.
        Parameters:
        path - the path name.
        Returns:
        the extracted filename.
      • stripFileExtension

        public String stripFileExtension​(String file)
        Removes the file extension from the given file name.
        Parameters:
        file - the file name.
        Returns:
        the file name without the file extension.
      • getFileExtension

        public String getFileExtension​(String file)
        Returns the file extension of the given file name. The returned value will contain the dot.
        Parameters:
        file - the file name.
        Returns:
        the file extension.
      • isSubDirectory

        public boolean isSubDirectory​(File base,
                                      File child)
                               throws IOException
        Checks, whether the child directory is a subdirectory of the base directory.
        Parameters:
        base - the base directory.
        child - the suspected child directory.
        Returns:
        true, if the child is a subdirectory of the base directory.
        Throws:
        IOException - if an IOError occured during the test.
      • findFileOnClassPath

        public File findFileOnClassPath​(String name)
                                 throws SecurityException
        Returns a reference to a file with the specified name that is located somewhere on the classpath. The code for this method is an adaptation of code supplied by Dave Postill.
        Parameters:
        name - the filename.
        Returns:
        a reference to a file or null if no file could be found.
        Throws:
        SecurityException - if access to the system properties or filesystem is forbidden.
      • getAbsolutePath

        public String getAbsolutePath​(String targetFile,
                                      String baseFile)
        Computes the absolute filename for the target file using the baseFile as root directory. If the baseFile is null or empty, the target file will be normalized (all navigation elements like ".." are removed).
        Parameters:
        targetFile - the target file name.
        baseFile - the base file (can be null).
        Returns:
        the absolute path.
      • getPath

        public String getPath​(String path)
        Returns the path-portion of the given path (anything before the last slash or backslash) or an empty string.
        Parameters:
        path - the path or filename from where to extract the path name.
        Returns:
        the extracted path or a empty string.
      • readClob

        public String readClob​(Clob clob)
                        throws IOException,
                               SQLException
        Converts a SQL-Clob object into a String. If the Clob is larger than 2^31 characters, we cannot convert it. If there are errors converting it, this method will log the cause and return null.
        Parameters:
        clob - the clob to be read as string.
        Returns:
        the string or null in case of errors.
        Throws:
        IOException
        SQLException
      • readBlob

        public byte[] readBlob​(Blob clob)
                        throws IOException,
                               SQLException
        Converts a SQL-Clob object into a String. If the Clob is larger than 2^31 characters, we cannot convert it. If there are errors converting it, this method will log the cause and return null.
        Parameters:
        clob - the clob to be read as string.
        Returns:
        the string or null in case of errors.
        Throws:
        IOException
        SQLException