Package org.apache.tika.io

Class IOUtils

java.lang.Object
org.apache.tika.io.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

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final Charset
    UTF_8
     

  • Constructor Summary

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

  • Method Summary

    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 long
    skip(InputStream input, long toSkip)
    Skips bytes from an input byte stream.
    static long
    skip(InputStream input, long toSkip, byte[] buffer)
     
    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.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • UTF_8

      public static final Charset UTF_8

  • Constructor Details

    • IOUtils

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

  • Method Details

    • 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

    • toByteArray

      @Deprecated public static byte[] toByteArray(String input) throws IOException
      Deprecated.
      Use String.getBytes()
      Get the contents of a String as a byte[] using the default character encoding of the platform.

      This is the same as String.getBytes().

      Parameters:
      input - the String to convert
      Returns:
      the requested byte array
      Throws:
      NullPointerException - if the input is null
      IOException - if an I/O error occurs (never occurs)

    • 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

    • skip

      public static long skip(InputStream input, long toSkip) throws IOException
      Skips bytes from an input byte stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for skip() implementations in subclasses of InputStream.

      Note that the implementation uses InputStream.read(byte[], int, int) rather than delegating to InputStream.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of bytes are skipped.

      Parameters:
      input - byte stream to skip
      toSkip - number of bytes to skip.
      Returns:
      number of bytes actually skipped.
      Throws:
      IOException - if there is a problem reading the file
      IllegalArgumentException - if toSkip is negative
      See Also:

    • skip

      public static long skip(InputStream input, long toSkip, byte[] buffer) throws IOException
      Throws:
      IOException