Module openj9.dataaccess
Package com.ibm.dataaccess

Class ByteArrayUnmarshaller

java.lang.Object
com.ibm.dataaccess.ByteArrayUnmarshaller
public final class ByteArrayUnmarshaller extends Object
Conversion routines to unmarshall Java binary types (short, int, long, float, double) from byte arrays.

With sign extensions enabled, the marshalled data is interpreted as signed and the data will be appropriately converted into the return type container. With sign extensions disabled, unfilled bits in the container will be set to zero. For example, -1 as one signed byte is 0xFF. Using readShort with signExtend true, the resultant short will contain 0xFFFF, which is -1 in Java's signed format. With signExtend false, the resultant short will contain 0x00FF, which is 255.

  • Method Summary

    Modifier and Type
    Method
    Description
    static double
    readDouble(byte[] byteArray, int offset, boolean bigEndian)
    Returns a double value copied from eight consecutive bytes of the byte array starting at the offset.
    static float
    readFloat(byte[] byteArray, int offset, boolean bigEndian)
    Returns a float value copied from four consecutive bytes of the byte array starting at the offset.
    static int
    readInt(byte[] byteArray, int offset, boolean bigEndian)
    Returns an int value copied from four consecutive bytes starting at the offset.
    static int
    readInt(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)
    Returns an int value copied from zero to four consecutive bytes of the byte array starting at the offset.
    static long
    readLong(byte[] byteArray, int offset, boolean bigEndian)
    Returns a long value copied from eight consecutive bytes of the byte array starting at the offset.
    static long
    readLong(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)
    Returns a long value copied from zero to eight consecutive bytes of the byte array starting at the offset.
    static short
    readShort(byte[] byteArray, int offset, boolean bigEndian)
    Returns a short value copied from two consecutive bytes of the byte array starting at the offset.
    static short
    readShort(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)
    Returns a short value copied from zero to two consecutive bytes of the byte array starting at the offset.

    Methods declared in class java.lang.Object

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

  • Method Details

    • readShort

      public static short readShort(byte[] byteArray, int offset, boolean bigEndian)
      Returns a short value copied from two consecutive bytes of the byte array starting at the offset.
      Parameters:
      byteArray - source
      offset - offset in the byte array
      bigEndian - if false the bytes will be copied in reverse (little endian) order
      Returns:
      short
      Throws:
      NullPointerException - if byteArray is null
      ArrayIndexOutOfBoundsException - if an invalid array access occurs

    • readShort

      public static short readShort(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)
      Returns a short value copied from zero to two consecutive bytes of the byte array starting at the offset.
      Parameters:
      byteArray - source
      offset - offset in the byte array
      bigEndian - if false the bytes will be copied in reverse (little endian) order
      numBytes - the number of bytes to unmarshall, must be 0-2 inclusive
      signExtend - if true and numBytes < 2 then the topmost bytes of the returned short will be sign extended
      Returns:
      long
      Throws:
      NullPointerException - if byteArray is null
      IllegalArgumentException - if numBytes < 0 or numBytes > 2
      ArrayIndexOutOfBoundsException - if an invalid array access occurs

    • readInt

      public static int readInt(byte[] byteArray, int offset, boolean bigEndian)
      Returns an int value copied from four consecutive bytes starting at the offset.
      Parameters:
      byteArray - source
      offset - offset in the byte array
      bigEndian - if false the bytes will be copied in reverse (little endian) order
      Returns:
      int
      Throws:
      NullPointerException - if byteArray is null
      ArrayIndexOutOfBoundsException - if an invalid array access occurs

    • readInt

      public static int readInt(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)
      Returns an int value copied from zero to four consecutive bytes of the byte array starting at the offset.
      Parameters:
      byteArray - source
      offset - offset in the byte array
      bigEndian - if false the bytes will be copied in reverse (little endian) order
      numBytes - the number of bytes to unmarshall, must be 0-4 inclusive
      signExtend - if true and numBytes < 4 then the topmost bytes of the returned int will be sign extended
      Returns:
      int
      Throws:
      NullPointerException - if byteArray is null
      IllegalArgumentException - if numBytes < 0 or numBytes > 4
      ArrayIndexOutOfBoundsException - if an invalid array access occurs

    • readLong

      public static long readLong(byte[] byteArray, int offset, boolean bigEndian)
      Returns a long value copied from eight consecutive bytes of the byte array starting at the offset.
      Parameters:
      byteArray - source
      offset - offset in the byte array
      bigEndian - if false the bytes will be copied in reverse (little endian) order
      Returns:
      long
      Throws:
      NullPointerException - if byteArray is null
      ArrayIndexOutOfBoundsException - if an invalid array access occurs

    • readLong

      public static long readLong(byte[] byteArray, int offset, boolean bigEndian, int numBytes, boolean signExtend)
      Returns a long value copied from zero to eight consecutive bytes of the byte array starting at the offset.
      Parameters:
      byteArray - source
      offset - offset in the byte array
      bigEndian - if false the bytes will be copied in reverse (little endian) order
      numBytes - the number of bytes to unmarshall, must be 0-8 inclusive
      signExtend - if true and numBytes < 8 then the topmost bytes of the returned long will be sign extended
      Returns:
      long
      Throws:
      NullPointerException - if byteArray is null
      IllegalArgumentException - if numBytes < 0 or numBytes > 8
      ArrayIndexOutOfBoundsException - if an invalid array access occurs

    • readFloat

      public static float readFloat(byte[] byteArray, int offset, boolean bigEndian)
      Returns a float value copied from four consecutive bytes of the byte array starting at the offset.
      Parameters:
      byteArray - source
      offset - offset in the byte array
      bigEndian - if false the bytes will be copied in reverse (little endian) order
      Returns:
      float
      Throws:
      NullPointerException - if byteArray is null
      ArrayIndexOutOfBoundsException - if an invalid array access occurs

    • readDouble

      public static double readDouble(byte[] byteArray, int offset, boolean bigEndian)
      Returns a double value copied from eight consecutive bytes of the byte array starting at the offset.
      Parameters:
      byteArray - source
      offset - offset in the byte array
      bigEndian - if false the bytes will be copied in reverse (little endian) order
      Returns:
      double
      Throws:
      NullPointerException - if byteArray is null
      ArrayIndexOutOfBoundsException - if an invalid array access occurs