Package org.apache.arrow.vector.util

Class Text

java.lang.Object
org.apache.arrow.vector.util.ReusableByteArray
org.apache.arrow.vector.util.Text
All Implemented Interfaces:
ReusableBuffer<byte[]>
public class Text extends ReusableByteArray
A simplified byte wrapper similar to Hadoop's Text class without all the dependencies. Lifted from Hadoop 2.7.1

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    Text.TextSerializer
    JSON serializer for Text.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    DEFAULT_MAX_LEN
     

    Fields inherited from class org.apache.arrow.vector.util.ReusableByteArray

    bytes, EMPTY_BYTES, length

  • Constructor Summary

    Constructors
    Constructor
    Description
    Text()
     
    Text(byte[] utf8)
    Construct from a byte array.
    Text(String string)
    Construct from a string.
    Text(Text utf8)
    Construct from another text.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    append(byte[] utf8, int start, int len)
    Append a range of bytes to the end of the given text.
    static int
    bytesToCodePoint(ByteBuffer bytes)
    Returns the next code point at the current position in the buffer.
    int
    charAt(int position)
    Returns the Unicode Scalar Value (32-bit integer value) for the character at position .
    void
    clear()
    Clear the string to empty.
    byte[]
    copyBytes()
    Get a copy of the bytes that is exactly the length of the data.
    static String
    decode(byte[] utf8)
    Converts the provided byte array to a String using the UTF-8 encoding.
    static String
    decode(byte[] utf8, int start, int length)
     
    static String
    decode(byte[] utf8, int start, int length, boolean replace)
    Converts the provided byte array to a String using the UTF-8 encoding.
    static ByteBuffer
    encode(String string)
    Converts the provided String to bytes using the UTF-8 encoding.
    static ByteBuffer
    encode(String string, boolean replace)
    Converts the provided String to bytes using the UTF-8 encoding.
    boolean
    equals(Object o)
     
    int
    find(String what)
     
    int
    find(String what, int start)
    Finds any occurrence of what in the backing buffer, starting as position start.
    byte[]
    getBytes()
    Returns the raw bytes; however, only data up to ReusableByteArray.getLength() is valid.
    void
    readWithKnownLength(DataInput in, int len)
    Read a Text object whose length is already known.
    void
    set(byte[] utf8)
    Set to an utf8 byte array.
    void
    set(byte[] utf8, int start, int len)
    Set the Text to range of bytes.
    void
    set(String string)
    Set to contain the contents of a string.
    void
    set(Text other)
    copy a text.
    String
    toString()
     
    static int
    utf8Length(String string)
    For the given string, returns the number of UTF-8 bytes required to encode the string.
    static void
    validateUTF8(byte[] utf8)
    Check if a byte array contains valid utf-8.
    static void
    validateUTF8(byte[] utf8, int start, int len)
    Check to see if a byte array is valid utf-8.
    static boolean
    validateUTF8NoThrow(byte[] utf8)
    Check if a byte array contains valid utf-8.

    Methods inherited from class org.apache.arrow.vector.util.ReusableByteArray

    getBuffer, getLength, hashCode, set, set, setCapacity

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Field Details

  • Constructor Details

    • Text

      public Text()

    • Text

      public Text(String string)
      Construct from a string.
      Parameters:
      string - initialize from that string

    • Text

      public Text(Text utf8)
      Construct from another text.
      Parameters:
      utf8 - initialize from that Text

    • Text

      public Text(byte[] utf8)
      Construct from a byte array.
      Parameters:
      utf8 - initialize from that byte array

  • Method Details

    • copyBytes

      public byte[] copyBytes()
      Get a copy of the bytes that is exactly the length of the data. See getBytes() for faster access to the underlying array.
      Returns:
      a copy of the underlying array

    • getBytes

      public byte[] getBytes()
      Returns the raw bytes; however, only data up to ReusableByteArray.getLength() is valid. Please use copyBytes() if you need the returned array to be precisely the length of the data.
      Returns:
      the underlying array

    • charAt

      public int charAt(int position)
      Returns the Unicode Scalar Value (32-bit integer value) for the character at position . Note that this method avoids using the converter or doing String instantiation.
      Parameters:
      position - the index of the char we want to retrieve
      Returns:
      the Unicode scalar value at position or -1 if the position is invalid or points to a trailing byte

    • find

      public int find(String what)

    • find

      public int find(String what, int start)
      Finds any occurrence of what in the backing buffer, starting as position start. The starting position is measured in bytes and the return value is in terms of byte position in the buffer. The backing buffer is not converted to a string for this operation.
      Parameters:
      what - the string to search for
      start - where to start from
      Returns:
      byte position of the first occurrence of the search string in the UTF-8 buffer or -1 if not found

    • set

      public void set(String string)
      Set to contain the contents of a string.
      Parameters:
      string - the string to initialize from

    • set

      public void set(byte[] utf8)
      Set to an utf8 byte array.
      Parameters:
      utf8 - the byte array to initialize from

    • set

      public void set(Text other)
      copy a text.
      Parameters:
      other - the text to initialize from

    • set

      public void set(byte[] utf8, int start, int len)
      Set the Text to range of bytes.
      Parameters:
      utf8 - the data to copy from
      start - the first position of the new string
      len - the number of bytes of the new string

    • append

      public void append(byte[] utf8, int start, int len)
      Append a range of bytes to the end of the given text.
      Parameters:
      utf8 - the data to copy from
      start - the first position to append from utf8
      len - the number of bytes to append

    • clear

      public void clear()
      Clear the string to empty.

      Note: For performance reasons, this call does not clear the underlying byte array that is retrievable via getBytes(). In order to free the byte-array memory, call set(byte[]) with an empty byte array (For example, new byte[0]).

    • toString

      public String toString()
      Overrides:
      toString in class ReusableByteArray

    • readWithKnownLength

      public void readWithKnownLength(DataInput in, int len) throws IOException
      Read a Text object whose length is already known. This allows creating Text from a stream which uses a different serialization format.
      Parameters:
      in - the input to initialize from
      len - how many bytes to read from in
      Throws:
      IOException - if something bad happens

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class ReusableByteArray

    • decode

      public static String decode(byte[] utf8) throws CharacterCodingException
      Converts the provided byte array to a String using the UTF-8 encoding. If the input is malformed, replace by a default value.
      Parameters:
      utf8 - bytes to decode
      Returns:
      the decoded string
      Throws:
      CharacterCodingException - if this is not valid UTF-8

    • decode

      public static String decode(byte[] utf8, int start, int length) throws CharacterCodingException
      Throws:
      CharacterCodingException

    • decode

      public static String decode(byte[] utf8, int start, int length, boolean replace) throws CharacterCodingException
      Converts the provided byte array to a String using the UTF-8 encoding. If replace is true, then malformed input is replaced with the substitution character, which is U+FFFD. Otherwise the method throws a MalformedInputException.
      Parameters:
      utf8 - the bytes to decode
      start - where to start from
      length - length of the bytes to decode
      replace - whether to replace malformed characters with U+FFFD
      Returns:
      the decoded string
      Throws:
      CharacterCodingException - if the input could not be decoded

    • encode

      public static ByteBuffer encode(String string) throws CharacterCodingException
      Converts the provided String to bytes using the UTF-8 encoding. If the input is malformed, invalid chars are replaced by a default value.
      Parameters:
      string - the string to encode
      Returns:
      ByteBuffer: bytes stores at ByteBuffer.array() and length is ByteBuffer.limit()
      Throws:
      CharacterCodingException - if the string could not be encoded

    • encode

      public static ByteBuffer encode(String string, boolean replace) throws CharacterCodingException
      Converts the provided String to bytes using the UTF-8 encoding. If replace is true, then malformed input is replaced with the substitution character, which is U+FFFD. Otherwise the method throws a MalformedInputException.
      Parameters:
      string - the string to encode
      replace - whether to replace malformed characters with U+FFFD
      Returns:
      ByteBuffer: bytes stores at ByteBuffer.array() and length is ByteBuffer.limit()
      Throws:
      CharacterCodingException - if the string could not be encoded

    • validateUTF8NoThrow

      public static boolean validateUTF8NoThrow(byte[] utf8)
      Check if a byte array contains valid utf-8.
      Parameters:
      utf8 - byte array
      Returns:
      true if the input is valid UTF-8. False otherwise.

    • validateUTF8

      public static void validateUTF8(byte[] utf8) throws MalformedInputException
      Check if a byte array contains valid utf-8.
      Parameters:
      utf8 - byte array
      Throws:
      MalformedInputException - if the byte array contains invalid utf-8

    • validateUTF8

      public static void validateUTF8(byte[] utf8, int start, int len) throws MalformedInputException
      Check to see if a byte array is valid utf-8.
      Parameters:
      utf8 - the array of bytes
      start - the offset of the first byte in the array
      len - the length of the byte sequence
      Throws:
      MalformedInputException - if the byte array contains invalid bytes

    • bytesToCodePoint

      public static int bytesToCodePoint(ByteBuffer bytes)
      Returns the next code point at the current position in the buffer. The buffer's position will be incremented. Any mark set on this buffer will be changed by this method!
      Parameters:
      bytes - the incoming bytes
      Returns:
      the corresponding unicode codepoint

    • utf8Length

      public static int utf8Length(String string)
      For the given string, returns the number of UTF-8 bytes required to encode the string.
      Parameters:
      string - text to encode
      Returns:
      number of UTF-8 bytes required to encode