Package com.yahoo.io

Class IOUtils

  • public abstract class IOUtils
extends java.lang.Object

    Some static io convenience methods.

    Author:
    bratseth, Bjorn Borud

    • Constructor Summary

      Constructors 
      Constructor Description
      IOUtils()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void closeAll​(java.util.List<java.io.Reader> readers)
      Convenience method for closing a list of readers.
      static void closeInputStream​(java.io.InputStream stream)
      Closes an input stream, or does nothing if the stream is null
      static void closeOutputStream​(java.io.OutputStream stream)
      Closes an output stream, or does nothing if the stream is null
      static void closeReader​(java.io.Reader reader)
      Closes a reader, or does nothing if the reader is null
      static void closeWriter​(java.io.Writer writer)
      Closes a writer, or does nothing if the writer is null
      static void copy​(java.io.File inFile, java.io.File outFile)
      Copies a file to another file.
      static void copy​(java.lang.String inFile, java.lang.String outFile)
      Copies a file to another file.
      static void copy​(java.lang.String inFile, java.lang.String outFile, int lineCount)
      Copies the n first lines of a file to another file.
      static void copyDirectory​(java.io.File sourceLocation, java.io.File targetLocation)
      Copies all files and subdirectories (infinitely recursively) in a directory to another.
      static void copyDirectory​(java.io.File sourceLocation, java.io.File targetLocation, int maxRecurseLevel)
      Copies all files and subdirectories in a directory to another.
      static void copyDirectory​(java.io.File sourceLocation, java.io.File targetLocation, int maxRecurseLevel, java.io.FilenameFilter filter)
      Copies all files and subdirectories in a directory to another.
      static void copyDirectoryInto​(java.io.File sourceLocation, java.io.File targetLocation)
      Copies the whole source directory (infinitely recursively) into the target directory.
      static int countLines​(java.lang.String file)
      Returns the number of lines in a file.
      static void createDirectory​(java.lang.String filename)
      Creates the directory path of this file if it does not exist
      static java.io.BufferedReader createReader​(java.io.File filename, java.lang.String encoding)
      Creates a buffered reader
      static java.io.BufferedReader createReader​(java.lang.String filename)
      Creates a buffered reader in the default encoding
      static java.io.BufferedReader createReader​(java.lang.String filename, java.lang.String encoding)
      Creates a buffered reader
      static java.io.BufferedWriter createWriter​(java.io.File file, boolean append)
      Creates a buffered writer in the default encoding
      static java.io.BufferedWriter createWriter​(java.io.File file, java.lang.String encoding, boolean append)
      Creates a buffered writer, and the directories to contain it if they do not exist
      static java.io.BufferedWriter createWriter​(java.lang.String filename, boolean append)
      Creates a buffered writer in the default encoding
      static java.io.BufferedWriter createWriter​(java.lang.String filename, java.lang.String encoding, boolean append)
      Creates a buffered writer, and the directories to contain it if they do not exist
      static java.util.List<java.lang.String> getLines​(java.lang.String fileName)
      Returns a list containing the lines in the given file as strings
      static java.lang.String readAll​(java.io.InputStream stream, java.nio.charset.Charset charset)
      Read an input stream completely into a string
      static java.lang.String readAll​(java.io.Reader reader)
      Reads all data from a reader into a string.
      static byte[] readBytes​(java.io.InputStream stream, int chunkSize)
      Reads all the content of the given input stream, in chunks of at max chunkSize
      static java.lang.String readFile​(java.io.File file)
      Reads the contents of a UTF-8 text file into a String.
      static byte[] readFileBytes​(java.io.File file)
      Reads the content of a file into a byte array
      static boolean recursiveDeleteDir​(java.io.File dir)
      Recursive deletion of directories
      static java.nio.ByteBuffer utf8ByteBuffer​(java.lang.String s)
      Encodes string as UTF-8 into ByteBuffer
      static void writeFile​(java.io.File file, byte[] content)
      Writes the given content to the file (replacing any existing content)
      static void writeFile​(java.io.File file, java.lang.String text, boolean append)
      Writes the given string to the file
      static void writeFile​(java.lang.String file, java.lang.String text, boolean append)
      Writes the given string to the file

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • IOUtils

        public IOUtils()

    • Method Detail

      • closeWriter

        public static void closeWriter​(java.io.Writer writer)
        Closes a writer, or does nothing if the writer is null

      • closeReader

        public static void closeReader​(java.io.Reader reader)
        Closes a reader, or does nothing if the reader is null

      • closeInputStream

        public static void closeInputStream​(java.io.InputStream stream)
        Closes an input stream, or does nothing if the stream is null

      • closeOutputStream

        public static void closeOutputStream​(java.io.OutputStream stream)
        Closes an output stream, or does nothing if the stream is null

      • createReader

        public static java.io.BufferedReader createReader​(java.io.File filename,
                                                  java.lang.String encoding)
                                           throws java.io.IOException
        Creates a buffered reader
        Parameters:
        filename - the name or path of the file
        encoding - the encoding of the file, for instance "UTF-8"
        Throws:
        java.io.IOException

      • createReader

        public static java.io.BufferedReader createReader​(java.lang.String filename,
                                                  java.lang.String encoding)
                                           throws java.io.IOException
        Creates a buffered reader
        Parameters:
        filename - the name or path of the file
        encoding - the encoding of the file, for instance "UTF-8"
        Throws:
        java.io.IOException

      • createReader

        public static java.io.BufferedReader createReader​(java.lang.String filename)
                                           throws java.io.IOException
        Creates a buffered reader in the default encoding
        Throws:
        java.io.IOException

      • createWriter

        public static java.io.BufferedWriter createWriter​(java.lang.String filename,
                                                  java.lang.String encoding,
                                                  boolean append)
                                           throws java.io.IOException
        Creates a buffered writer, and the directories to contain it if they do not exist
        Parameters:
        filename - the name or path of the file
        encoding - the encoding to use, for instance "UTF-8"
        append - whether to append to the files if it exists
        Throws:
        java.io.IOException

      • createWriter

        public static java.io.BufferedWriter createWriter​(java.io.File file,
                                                  java.lang.String encoding,
                                                  boolean append)
                                           throws java.io.IOException
        Creates a buffered writer, and the directories to contain it if they do not exist
        Parameters:
        file - the file to write to
        encoding - the encoding to use, for instance "UTF-8"
        append - whether to append to the files if it exists
        Throws:
        java.io.IOException

      • createWriter

        public static java.io.BufferedWriter createWriter​(java.lang.String filename,
                                                  boolean append)
                                           throws java.io.IOException
        Creates a buffered writer in the default encoding
        Parameters:
        filename - the name or path of the file
        append - whether to append to the files if it exists
        Throws:
        java.io.IOException

      • createWriter

        public static java.io.BufferedWriter createWriter​(java.io.File file,
                                                  boolean append)
                                           throws java.io.IOException
        Creates a buffered writer in the default encoding
        Parameters:
        file - the file to write to
        append - whether to append to the files if it exists
        Throws:
        java.io.IOException

      • createDirectory

        public static void createDirectory​(java.lang.String filename)
        Creates the directory path of this file if it does not exist

      • copy

        public static void copy​(java.lang.String inFile,
                        java.lang.String outFile,
                        int lineCount)
                 throws java.io.IOException
        Copies the n first lines of a file to another file. If the out file exists it will be overwritten
        Throws:
        java.io.IOException - if copying fails

      • copy

        public static void copy​(java.lang.String inFile,
                        java.lang.String outFile)
                 throws java.io.IOException
        Copies a file to another file. If the out file exists it will be overwritten.
        Throws:
        java.io.IOException - if copying fails

      • copy

        public static void copy​(java.io.File inFile,
                        java.io.File outFile)
                 throws java.io.IOException
        Copies a file to another file. If the out file exists it will be overwritten.
        Throws:
        java.io.IOException

      • copyDirectory

        public static void copyDirectory​(java.io.File sourceLocation,
                                 java.io.File targetLocation,
                                 int maxRecurseLevel)
                          throws java.io.IOException
        Copies all files and subdirectories in a directory to another. Any existing files are overwritten.
        Parameters:
        sourceLocation - the source directory
        targetLocation - the target directory
        maxRecurseLevel - if this is 1, only files immediately in sourceLocation are copied, if it is 2, then files contained in immediate subdirectories are copied, etc. If it is 0, sourceLocation will only be copied if it is a file, not a directory. If it is negative, recursion is infinite.
        Throws:
        java.io.IOException - if copying any file fails. This will typically result in some files being copied and others not, i.e this method is not exception safe

      • copyDirectory

        public static void copyDirectory​(java.io.File sourceLocation,
                                 java.io.File targetLocation,
                                 int maxRecurseLevel,
                                 java.io.FilenameFilter filter)
                          throws java.io.IOException
        Copies all files and subdirectories in a directory to another. Any existing files are overwritten.
        Parameters:
        sourceLocation - the source directory
        targetLocation - the target directory
        maxRecurseLevel - if this is 1, only files immediately in sourceLocation are copied, if it is 2, then files contained in immediate subdirectories are copied, etc. If it is 0, sourceLocation will only be copied if it is a file, not a directory. If it is negative, recursion is infinite.
        filter - Only copy files passing through filter.
        Throws:
        java.io.IOException - if copying any file fails. This will typically result in some files being copied and others not, i.e this method is not exception safe

      • copyDirectory

        public static void copyDirectory​(java.io.File sourceLocation,
                                 java.io.File targetLocation)
                          throws java.io.IOException
        Copies all files and subdirectories (infinitely recursively) in a directory to another. Any existing files are overwritten.
        Parameters:
        sourceLocation - the source directory
        targetLocation - the target directory
        Throws:
        java.io.IOException - if copying any file fails. This will typically result in some files being copied and others not, i.e this method is not exception safe

      • copyDirectoryInto

        public static void copyDirectoryInto​(java.io.File sourceLocation,
                                     java.io.File targetLocation)
                              throws java.io.IOException
        Copies the whole source directory (infinitely recursively) into the target directory.
        Throws:
        java.io.IOException - if copying any file fails. This will typically result in some files being copied and others not, i.e this method is not exception safe

      • countLines

        public static int countLines​(java.lang.String file)
        Returns the number of lines in a file. If the file does not exists, 0 is returned

      • getLines

        public static java.util.List<java.lang.String> getLines​(java.lang.String fileName)
                                                 throws java.io.IOException
        Returns a list containing the lines in the given file as strings
        Returns:
        a list of Strings for the lines of the file, in order
        Throws:
        java.io.IOException - if the file could not be read

      • recursiveDeleteDir

        public static boolean recursiveDeleteDir​(java.io.File dir)
        Recursive deletion of directories

      • utf8ByteBuffer

        public static java.nio.ByteBuffer utf8ByteBuffer​(java.lang.String s)
        Encodes string as UTF-8 into ByteBuffer

      • readFile

        public static java.lang.String readFile​(java.io.File file)
                                 throws java.io.IOException
        Reads the contents of a UTF-8 text file into a String.
        Parameters:
        file - the file to read, or null
        Returns:
        the file content as a string, or null if the input file was null
        Throws:
        java.io.IOException

      • readBytes

        public static byte[] readBytes​(java.io.InputStream stream,
                               int chunkSize)
                        throws java.io.IOException
        Reads all the content of the given input stream, in chunks of at max chunkSize
        Throws:
        java.io.IOException

      • readFileBytes

        public static byte[] readFileBytes​(java.io.File file)
                            throws java.io.IOException
        Reads the content of a file into a byte array
        Throws:
        java.io.IOException

      • readAll

        public static java.lang.String readAll​(java.io.Reader reader)
                                throws java.io.IOException
        Reads all data from a reader into a string. Uses a buffer to speed up reading.
        Throws:
        java.io.IOException

      • readAll

        public static java.lang.String readAll​(java.io.InputStream stream,
                                       java.nio.charset.Charset charset)
                                throws java.io.IOException
        Read an input stream completely into a string
        Throws:
        java.io.IOException

      • closeAll

        public static void closeAll​(java.util.List<java.io.Reader> readers)
        Convenience method for closing a list of readers. Does nothing if the given reader list is null.

      • writeFile

        public static void writeFile​(java.io.File file,
                             java.lang.String text,
                             boolean append)
                      throws java.io.IOException
        Writes the given string to the file
        Throws:
        java.io.IOException

      • writeFile

        public static void writeFile​(java.io.File file,
                             byte[] content)
                      throws java.io.UncheckedIOException
        Writes the given content to the file (replacing any existing content)
        Throws:
        java.io.UncheckedIOException

      • writeFile

        public static void writeFile​(java.lang.String file,
                             java.lang.String text,
                             boolean append)
                      throws java.io.IOException
        Writes the given string to the file
        Throws:
        java.io.IOException