Package org.apache.tika.io

Class IOUtils

  • public class IOUtils
extends Object
    General IO stream manipulation utilities.

    This class provides static utility methods for input/output operations.

    • closeQuietly - these methods close a stream ignoring nulls and exceptions
    • toXxx/read - these methods read data from a stream
    • write - these methods write data to a stream
    • copy - these methods copy all the data from one stream to another
    • contentEquals - these methods compare the content of two streams

    The byte-to-char methods and char-to-byte methods involve a conversion step. Two methods are provided in each case, one that uses the platform default encoding and the other which allows you to specify an encoding. You are encouraged to always specify an encoding because relying on the platform default can lead to unexpected results, for example when moving from development to production.

    All the methods in this class that read a stream are buffered internally. This means that there is no cause to use a BufferedInputStream or BufferedReader. The default buffer size of 4K has been shown to be efficient in tests.

    Wherever possible, the methods in this class do not flush or close the stream. This is to avoid making non-portable assumptions about the streams' origin and further use. Thus the caller is still responsible for closing streams after use.

    Origin of code: Excalibur.

    Since:
    Apache Tika 0.4, copied (partially) from Commons IO 1.4
    Author:
    Peter Donald, Jeff Turner, Matthew Hawthorne, Stephen Colebourne, Gareth Davis, Ian Springer, Niall Pemberton, Sandy McArthur

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static Charset UTF_8  

    • Constructor Summary

      Constructors 
      Constructor Description
      IOUtils()
      Instances should NOT be constructed in standard programming.

    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static void closeQuietly​(InputStream input)
      Unconditionally close an InputStream.
      static void closeQuietly​(OutputStream output)
      Unconditionally close an OutputStream.
      static void closeQuietly​(Reader input)
      Unconditionally close an Reader.
      static void closeQuietly​(Writer output)
      Unconditionally close a Writer.
      static void closeQuietly​(Channel channel)
      Unconditionally close a Channel.
      static boolean contentEquals​(InputStream input1, InputStream input2)
      Compare the contents of two Streams to determine if they are equal or not.
      static boolean contentEquals​(Reader input1, Reader input2)
      Compare the contents of two Readers to determine if they are equal or not.
      static int copy​(InputStream input, OutputStream output)
      Copy bytes from an InputStream to an OutputStream.
      static void copy​(InputStream input, Writer output)
      Copy bytes from an InputStream to chars on a Writer using the default character encoding of the platform.
      static void copy​(InputStream input, Writer output, String encoding)
      Copy bytes from an InputStream to chars on a Writer using the specified character encoding.
      static void copy​(Reader input, OutputStream output)
      Copy chars from a Reader to bytes on an OutputStream using the default character encoding of the platform, and calling flush.
      static void copy​(Reader input, OutputStream output, String encoding)
      Copy chars from a Reader to bytes on an OutputStream using the specified character encoding, and calling flush.
      static int copy​(Reader input, Writer output)
      Copy chars from a Reader to a Writer.
      static long copyLarge​(InputStream input, OutputStream output)
      Copy bytes from a large (over 2GB) InputStream to an OutputStream.
      static long copyLarge​(Reader input, Writer output)
      Copy chars from a large (over 2GB) Reader to a Writer.
      static int read​(InputStream input, byte[] buffer, int offset, int length)
      Reads bytes from an input stream.
      static List<String> readLines​(InputStream input)
      Get the contents of an InputStream as a list of Strings, one entry per line, using the default character encoding of the platform.
      static List<String> readLines​(InputStream input, String encoding)
      Get the contents of an InputStream as a list of Strings, one entry per line, using the specified character encoding.
      static List<String> readLines​(Reader input)
      Get the contents of a Reader as a list of Strings, one entry per line.
      static byte[] toByteArray​(InputStream input)
      Get the contents of an InputStream as a byte[].
      static byte[] toByteArray​(Reader input)
      Get the contents of a Reader as a byte[] using the default character encoding of the platform.
      static byte[] toByteArray​(Reader input, String encoding)
      Get the contents of a Reader as a byte[] using the specified character encoding.
      static byte[] toByteArray​(String input)
      Deprecated.
      Use String.getBytes()
      static char[] toCharArray​(InputStream is)
      Get the contents of an InputStream as a character array using the default character encoding of the platform.
      static char[] toCharArray​(InputStream is, String encoding)
      Get the contents of an InputStream as a character array using the specified character encoding.
      static char[] toCharArray​(Reader input)
      Get the contents of a Reader as a character array.
      static InputStream toInputStream​(CharSequence input)
      Convert the specified CharSequence to an input stream, encoded as bytes using the default character encoding of the platform.
      static InputStream toInputStream​(CharSequence input, String encoding)
      Convert the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.
      static InputStream toInputStream​(String input)
      Convert the specified string to an input stream, encoded as bytes using the default character encoding of the platform.
      static InputStream toInputStream​(String input, String encoding)
      Convert the specified string to an input stream, encoded as bytes using the specified character encoding.
      static String toString​(byte[] input)
      Deprecated.
      Use String(byte[])
      static String toString​(byte[] input, String encoding)
      Deprecated.
      Use String(byte[],String)
      static String toString​(InputStream input)
      Get the contents of an InputStream as a String using the default character encoding of the platform.
      static String toString​(InputStream input, String encoding)
      Get the contents of an InputStream as a String using the specified character encoding.
      static String toString​(Reader input)
      Get the contents of a Reader as a String.
      static void write​(byte[] data, OutputStream output)
      Writes bytes from a byte[] to an OutputStream.
      static void write​(byte[] data, Writer output)
      Writes bytes from a byte[] to chars on a Writer using the default character encoding of the platform.
      static void write​(byte[] data, Writer output, String encoding)
      Writes bytes from a byte[] to chars on a Writer using the specified character encoding.
      static void write​(char[] data, OutputStream output)
      Writes chars from a char[] to bytes on an OutputStream.
      static void write​(char[] data, OutputStream output, String encoding)
      Writes chars from a char[] to bytes on an OutputStream using the specified character encoding.
      static void write​(char[] data, Writer output)
      Writes chars from a char[] to a Writer using the default character encoding of the platform.
      static void write​(CharSequence data, OutputStream output)
      Writes chars from a CharSequence to bytes on an OutputStream using the default character encoding of the platform.
      static void write​(CharSequence data, OutputStream output, String encoding)
      Writes chars from a CharSequence to bytes on an OutputStream using the specified character encoding.
      static void write​(CharSequence data, Writer output)
      Writes chars from a CharSequence to a Writer.
      static void write​(StringBuffer data, OutputStream output)
      Deprecated.
      replaced by write(CharSequence, OutputStream)
      static void write​(StringBuffer data, OutputStream output, String encoding)
      Deprecated.
      replaced by write(CharSequence, OutputStream, String)
      static void write​(StringBuffer data, Writer output)
      Deprecated.
      replaced by write(CharSequence, Writer)
      static void write​(String data, OutputStream output)
      Writes chars from a String to bytes on an OutputStream using the default character encoding of the platform.
      static void write​(String data, OutputStream output, String encoding)
      Writes chars from a String to bytes on an OutputStream using the specified character encoding.
      static void write​(String data, Writer output)
      Writes chars from a String to a Writer.

    • Field Detail

      • UTF_8

        public static final Charset UTF_8

    • Constructor Detail

      • IOUtils

        public IOUtils()
        Instances should NOT be constructed in standard programming.

    • Method Detail

      • closeQuietly

        public static void closeQuietly​(Reader input)
        Unconditionally close an Reader.

        Equivalent to Reader.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Parameters:
        input - the Reader to close, may be null or already closed

      • closeQuietly

        public static void closeQuietly​(Channel channel)
        Unconditionally close a Channel.

        Equivalent to Channel.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Parameters:
        channel - the Channel to close, may be null or already closed

      • closeQuietly

        public static void closeQuietly​(Writer output)
        Unconditionally close a Writer.

        Equivalent to Writer.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Parameters:
        output - the Writer to close, may be null or already closed

      • closeQuietly

        public static void closeQuietly​(InputStream input)
        Unconditionally close an InputStream.

        Equivalent to InputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Parameters:
        input - the InputStream to close, may be null or already closed

      • closeQuietly

        public static void closeQuietly​(OutputStream output)
        Unconditionally close an OutputStream.

        Equivalent to OutputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks.

        Parameters:
        output - the OutputStream to close, may be null or already closed

      • toByteArray

        public static byte[] toByteArray​(InputStream input)
                          throws IOException
        Get the contents of an InputStream as a byte[].

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs

      • toByteArray

        public static byte[] toByteArray​(Reader input)
                          throws IOException
        Get the contents of a Reader as a byte[] using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        input - the Reader to read from
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs

      • toByteArray

        public static byte[] toByteArray​(Reader input,
                                 String encoding)
                          throws IOException
        Get the contents of a Reader as a byte[] using the specified character encoding.

        Character encoding names can be found at IANA.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        input - the Reader to read from
        encoding - the encoding to use, null means platform default
        Returns:
        the requested byte array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • toCharArray

        public static char[] toCharArray​(InputStream is)
                          throws IOException
        Get the contents of an InputStream as a character array using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        is - the InputStream to read from
        Returns:
        the requested character array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • toCharArray

        public static char[] toCharArray​(InputStream is,
                                 String encoding)
                          throws IOException
        Get the contents of an InputStream as a character array using the specified character encoding.

        Character encoding names can be found at IANA.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        is - the InputStream to read from
        encoding - the encoding to use, null means platform default
        Returns:
        the requested character array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • toCharArray

        public static char[] toCharArray​(Reader input)
                          throws IOException
        Get the contents of a Reader as a character array.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        input - the Reader to read from
        Returns:
        the requested character array
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • toString

        public static String toString​(InputStream input)
                       throws IOException
        Get the contents of an InputStream as a String using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs

      • toString

        public static String toString​(InputStream input,
                              String encoding)
                       throws IOException
        Get the contents of an InputStream as a String using the specified character encoding.

        Character encoding names can be found at IANA.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from
        encoding - the encoding to use, null means platform default
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs

      • toString

        public static String toString​(Reader input)
                       throws IOException
        Get the contents of a Reader as a String.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        input - the Reader to read from
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs

      • toString

        @Deprecated
public static String toString​(byte[] input)
                       throws IOException
        Deprecated.
        Use String(byte[])
        Get the contents of a byte[] as a String using the default character encoding of the platform.
        Parameters:
        input - the byte array to read from
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs (never occurs)

      • toString

        @Deprecated
public static String toString​(byte[] input,
                              String encoding)
                       throws IOException
        Deprecated.
        Use String(byte[],String)
        Get the contents of a byte[] as a String using the specified character encoding.

        Character encoding names can be found at IANA.

        Parameters:
        input - the byte array to read from
        encoding - the encoding to use, null means platform default
        Returns:
        the requested String
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs (never occurs)

      • readLines

        public static List<String> readLines​(InputStream input)
                              throws IOException
        Get the contents of an InputStream as a list of Strings, one entry per line, using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from, not null
        Returns:
        the list of Strings, never null
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • readLines

        public static List<String> readLines​(InputStream input,
                                     String encoding)
                              throws IOException
        Get the contents of an InputStream as a list of Strings, one entry per line, using the specified character encoding.

        Character encoding names can be found at IANA.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from, not null
        encoding - the encoding to use, null means platform default
        Returns:
        the list of Strings, never null
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • readLines

        public static List<String> readLines​(Reader input)
                              throws IOException
        Get the contents of a Reader as a list of Strings, one entry per line.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        input - the Reader to read from, not null
        Returns:
        the list of Strings, never null
        Throws:
        NullPointerException - if the input is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • toInputStream

        public static InputStream toInputStream​(CharSequence input)
        Convert the specified CharSequence to an input stream, encoded as bytes using the default character encoding of the platform.
        Parameters:
        input - the CharSequence to convert
        Returns:
        an input stream
        Since:
        IO 2.0

      • toInputStream

        public static InputStream toInputStream​(CharSequence input,
                                        String encoding)
                                 throws IOException
        Convert the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.

        Character encoding names can be found at IANA.

        Parameters:
        input - the CharSequence to convert
        encoding - the encoding to use, null means platform default
        Returns:
        an input stream
        Throws:
        IOException - if the encoding is invalid
        Since:
        IO 2.0

      • toInputStream

        public static InputStream toInputStream​(String input)
        Convert the specified string to an input stream, encoded as bytes using the default character encoding of the platform.
        Parameters:
        input - the string to convert
        Returns:
        an input stream
        Since:
        Commons IO 1.1

      • toInputStream

        public static InputStream toInputStream​(String input,
                                        String encoding)
                                 throws IOException
        Convert the specified string to an input stream, encoded as bytes using the specified character encoding.

        Character encoding names can be found at IANA.

        Parameters:
        input - the string to convert
        encoding - the encoding to use, null means platform default
        Returns:
        an input stream
        Throws:
        IOException - if the encoding is invalid
        Since:
        Commons IO 1.1

      • write

        public static void write​(byte[] data,
                         OutputStream output)
                  throws IOException
        Writes bytes from a byte[] to an OutputStream.
        Parameters:
        data - the byte array to write, do not modify during output, null ignored
        output - the OutputStream to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        public static void write​(byte[] data,
                         Writer output)
                  throws IOException
        Writes bytes from a byte[] to chars on a Writer using the default character encoding of the platform.

        This method uses String(byte[]).

        Parameters:
        data - the byte array to write, do not modify during output, null ignored
        output - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        public static void write​(byte[] data,
                         Writer output,
                         String encoding)
                  throws IOException
        Writes bytes from a byte[] to chars on a Writer using the specified character encoding.

        Character encoding names can be found at IANA.

        This method uses String(byte[], String).

        Parameters:
        data - the byte array to write, do not modify during output, null ignored
        output - the Writer to write to
        encoding - the encoding to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        public static void write​(char[] data,
                         Writer output)
                  throws IOException
        Writes chars from a char[] to a Writer using the default character encoding of the platform.
        Parameters:
        data - the char array to write, do not modify during output, null ignored
        output - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        public static void write​(char[] data,
                         OutputStream output)
                  throws IOException
        Writes chars from a char[] to bytes on an OutputStream.

        This method uses String(char[]) and String.getBytes().

        Parameters:
        data - the char array to write, do not modify during output, null ignored
        output - the OutputStream to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        public static void write​(char[] data,
                         OutputStream output,
                         String encoding)
                  throws IOException
        Writes chars from a char[] to bytes on an OutputStream using the specified character encoding.

        Character encoding names can be found at IANA.

        This method uses String(char[]) and String.getBytes(String).

        Parameters:
        data - the char array to write, do not modify during output, null ignored
        output - the OutputStream to write to
        encoding - the encoding to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        public static void write​(CharSequence data,
                         Writer output)
                  throws IOException
        Writes chars from a CharSequence to a Writer.
        Parameters:
        data - the CharSequence to write, null ignored
        output - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 2.0

      • write

        public static void write​(CharSequence data,
                         OutputStream output)
                  throws IOException
        Writes chars from a CharSequence to bytes on an OutputStream using the default character encoding of the platform.

        This method uses String.getBytes().

        Parameters:
        data - the CharSequence to write, null ignored
        output - the OutputStream to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 2.0

      • write

        public static void write​(CharSequence data,
                         OutputStream output,
                         String encoding)
                  throws IOException
        Writes chars from a CharSequence to bytes on an OutputStream using the specified character encoding.

        Character encoding names can be found at IANA.

        This method uses String.getBytes(String).

        Parameters:
        data - the CharSequence to write, null ignored
        output - the OutputStream to write to
        encoding - the encoding to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 2.0

      • write

        public static void write​(String data,
                         Writer output)
                  throws IOException
        Writes chars from a String to a Writer.
        Parameters:
        data - the String to write, null ignored
        output - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        public static void write​(String data,
                         OutputStream output)
                  throws IOException
        Writes chars from a String to bytes on an OutputStream using the default character encoding of the platform.

        This method uses String.getBytes().

        Parameters:
        data - the String to write, null ignored
        output - the OutputStream to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        public static void write​(String data,
                         OutputStream output,
                         String encoding)
                  throws IOException
        Writes chars from a String to bytes on an OutputStream using the specified character encoding.

        Character encoding names can be found at IANA.

        This method uses String.getBytes(String).

        Parameters:
        data - the String to write, null ignored
        output - the OutputStream to write to
        encoding - the encoding to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        @Deprecated
public static void write​(StringBuffer data,
                         Writer output)
                  throws IOException
        Deprecated.
        replaced by write(CharSequence, Writer)
        Writes chars from a StringBuffer to a Writer.
        Parameters:
        data - the StringBuffer to write, null ignored
        output - the Writer to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        @Deprecated
public static void write​(StringBuffer data,
                         OutputStream output)
                  throws IOException
        Deprecated.
        replaced by write(CharSequence, OutputStream)
        Writes chars from a StringBuffer to bytes on an OutputStream using the default character encoding of the platform.

        This method uses String.getBytes().

        Parameters:
        data - the StringBuffer to write, null ignored
        output - the OutputStream to write to
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • write

        @Deprecated
public static void write​(StringBuffer data,
                         OutputStream output,
                         String encoding)
                  throws IOException
        Deprecated.
        replaced by write(CharSequence, OutputStream, String)
        Writes chars from a StringBuffer to bytes on an OutputStream using the specified character encoding.

        Character encoding names can be found at IANA.

        This method uses String.getBytes(String).

        Parameters:
        data - the StringBuffer to write, null ignored
        output - the OutputStream to write to
        encoding - the encoding to use, null means platform default
        Throws:
        NullPointerException - if output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • copy

        public static int copy​(InputStream input,
                       OutputStream output)
                throws IOException
        Copy bytes from an InputStream to an OutputStream.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Large streams (over 2GB) will return a bytes copied value of -1 after the copy has completed since the correct number of bytes cannot be returned as an int. For large streams use the copyLarge(InputStream, OutputStream) method.

        Parameters:
        input - the InputStream to read from
        output - the OutputStream to write to
        Returns:
        the number of bytes copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        ArithmeticException - if the byte count is too large
        Since:
        Commons IO 1.1

      • copyLarge

        public static long copyLarge​(InputStream input,
                             OutputStream output)
                      throws IOException
        Copy bytes from a large (over 2GB) InputStream to an OutputStream.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Parameters:
        input - the InputStream to read from
        output - the OutputStream to write to
        Returns:
        the number of bytes copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.3

      • copy

        public static void copy​(InputStream input,
                        Writer output)
                 throws IOException
        Copy bytes from an InputStream to chars on a Writer using the default character encoding of the platform.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        This method uses InputStreamReader.

        Parameters:
        input - the InputStream to read from
        output - the Writer to write to
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • copy

        public static void copy​(InputStream input,
                        Writer output,
                        String encoding)
                 throws IOException
        Copy bytes from an InputStream to chars on a Writer using the specified character encoding.

        This method buffers the input internally, so there is no need to use a BufferedInputStream.

        Character encoding names can be found at IANA.

        This method uses InputStreamReader.

        Parameters:
        input - the InputStream to read from
        output - the Writer to write to
        encoding - the encoding to use, null means platform default
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • copy

        public static int copy​(Reader input,
                       Writer output)
                throws IOException
        Copy chars from a Reader to a Writer.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Large streams (over 2GB) will return a chars copied value of -1 after the copy has completed since the correct number of chars cannot be returned as an int. For large streams use the copyLarge(Reader, Writer) method.

        Parameters:
        input - the Reader to read from
        output - the Writer to write to
        Returns:
        the number of characters copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        ArithmeticException - if the character count is too large
        Since:
        Commons IO 1.1

      • copyLarge

        public static long copyLarge​(Reader input,
                             Writer output)
                      throws IOException
        Copy chars from a large (over 2GB) Reader to a Writer.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Parameters:
        input - the Reader to read from
        output - the Writer to write to
        Returns:
        the number of characters copied
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.3

      • copy

        public static void copy​(Reader input,
                        OutputStream output)
                 throws IOException
        Copy chars from a Reader to bytes on an OutputStream using the default character encoding of the platform, and calling flush.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Due to the implementation of OutputStreamWriter, this method performs a flush.

        This method uses OutputStreamWriter.

        Parameters:
        input - the Reader to read from
        output - the OutputStream to write to
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • copy

        public static void copy​(Reader input,
                        OutputStream output,
                        String encoding)
                 throws IOException
        Copy chars from a Reader to bytes on an OutputStream using the specified character encoding, and calling flush.

        This method buffers the input internally, so there is no need to use a BufferedReader.

        Character encoding names can be found at IANA.

        Due to the implementation of OutputStreamWriter, this method performs a flush.

        This method uses OutputStreamWriter.

        Parameters:
        input - the Reader to read from
        output - the OutputStream to write to
        encoding - the encoding to use, null means platform default
        Throws:
        NullPointerException - if the input or output is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • contentEquals

        public static boolean contentEquals​(InputStream input1,
                                    InputStream input2)
                             throws IOException
        Compare the contents of two Streams to determine if they are equal or not.

        This method buffers the input internally using BufferedInputStream if they are not already buffered.

        Parameters:
        input1 - the first stream
        input2 - the second stream
        Returns:
        true if the content of the streams are equal or they both don't exist, false otherwise
        Throws:
        NullPointerException - if either input is null
        IOException - if an I/O error occurs

      • contentEquals

        public static boolean contentEquals​(Reader input1,
                                    Reader input2)
                             throws IOException
        Compare the contents of two Readers to determine if they are equal or not.

        This method buffers the input internally using BufferedReader if they are not already buffered.

        Parameters:
        input1 - the first reader
        input2 - the second reader
        Returns:
        true if the content of the readers are equal or they both don't exist, false otherwise
        Throws:
        NullPointerException - if either input is null
        IOException - if an I/O error occurs
        Since:
        Commons IO 1.1

      • read

        public static int read​(InputStream input,
                       byte[] buffer,
                       int offset,
                       int length)
                throws IOException
        Reads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of InputStream.
        Parameters:
        input - where to read input from
        buffer - destination
        offset - initial offset into buffer
        length - length to read, must be >= 0
        Returns:
        actual length read; may be less than requested if EOF was reached
        Throws:
        IOException - if a read error occurs
        Since:
        2.2