Class UInt256

java.lang.Object
com.codename1.crypto.UInt256
All Implemented Interfaces:
Comparable<UInt256>
public final class UInt256 extends Object implements Comparable<UInt256>

An unsigned 256-bit integer: the width of every EVM quantity and wide enough for any Bitcoin or Solana amount. Immutable.

Arithmetic is exact and refuses to wrap: an overflow or a negative result throws ArithmeticException, because a balance that silently wraps is a loss of funds. parseUnits(String, int) and formatUnits(int) move between base units and the decimal amounts people read ("1.5" ether is 1500000000000000000 wei).

The device class library has no java.math, so this is what the shared crypto API uses for amounts.

  • Field Details

    • ZERO

      public static final UInt256 ZERO
      Zero.

    • ONE

      public static final UInt256 ONE
      One.

    • MAX

      public static final UInt256 MAX
      2^256 - 1.

  • Method Details

    • valueOf

      public static UInt256 valueOf(long value)
      The value of a non-negative long.

    • fromBytes

      public static UInt256 fromBytes(byte[] bigEndian)
      Reads a big-endian unsigned integer of at most 32 significant bytes; leading zero bytes beyond 32 are allowed.

    • fromBytes

      public static UInt256 fromBytes(byte[] data, int offset, int length)
      Reads length big-endian bytes at offset.

    • parse

      public static UInt256 parse(String text)

      Parses decimal digits, or hexadecimal after 0x.

      Throws
      • NumberFormatException: for anything else, a sign, or a value above MAX

    • parse

      public static UInt256 parse(String digits, int radix)
      Parses digits in radix 10 or 16, no prefix.

    • parseUnits

      public static UInt256 parseUnits(String amount, int decimals)

      Parses a decimal amount into base units: parseUnits("1.5", 18) is 1.5 ether in wei.

      Throws
      • NumberFormatException: for a malformed amount or more fraction digits than decimals

    • formatUnits

      public String formatUnits(int decimals)
      Formats base units as a decimal amount, without trailing fraction zeros: formatUnits(1500000000000000000, 18) is "1.5".

    • add

      public UInt256 add(UInt256 other)

      this + other.

      Throws
      • ArithmeticException: when the sum exceeds MAX

    • subtract

      public UInt256 subtract(UInt256 other)

      this - other.

      Throws
      • ArithmeticException: when other is larger

    • multiply

      public UInt256 multiply(UInt256 other)

      this * other.

      Throws
      • ArithmeticException: when the product exceeds MAX

    • multiply

      public UInt256 multiply(long factor)
      this * factor for a small non-negative factor.

    • divideAndRemainder

      public UInt256[] divideAndRemainder(UInt256 divisor)

      The quotient and remainder of this / divisor.

      Throws
      • ArithmeticException: for a zero divisor

    • divide

      public UInt256 divide(UInt256 divisor)
      this / divisor, rounded down.

    • mod

      public UInt256 mod(UInt256 divisor)
      this mod divisor.

    • shiftLeft

      public UInt256 shiftLeft(int bits)
      this << bits, refusing to drop set bits.

    • shiftRight

      public UInt256 shiftRight(int bits)
      this >>> bits.

    • tenPow

      public static UInt256 tenPow(int exponent)
      10^exponent, for unit conversions.

    • testBit

      public boolean testBit(int n)
      Tells whether bit n (0 is the lowest) is set.

    • bitLength

      public int bitLength()
      The number of significant bits; 0 for zero.

    • isZero

      public boolean isZero()
      Tells whether this is zero.

    • longValueExact

      public long longValueExact()

      The value as a long.

      Throws
      • ArithmeticException: when it does not fit in 63 bits

    • toBytes32

      public byte[] toBytes32()
      The 32 big-endian bytes.

    • toMinimalBytes

      public byte[] toMinimalBytes()
      The minimal big-endian bytes, empty for zero: the RLP and JSON-RPC quantity form.

    • toHex

      public String toHex()
      Lowercase hexadecimal without leading zeros or prefix; "0" for zero.

    • toQuantity

      public String toQuantity()
      The JSON-RPC quantity form, 0x and minimal hex: 0x0, 0x1a.

    • toString

      public String toString()
      The decimal digits.
      Overrides:
      toString in class Object

    • compareTo

      public int compareTo(UInt256 other)
      Description copied from interface: Comparable

      Compares this object to the specified object to determine their relative order.

      Parameters
      • another: the object to compare to this instance.
      Returns
      Specified by:
      compareTo in interface Comparable<UInt256>
      Returns:

      a negative integer if this instance is less than another; a positive integer if this instance is greater than another; 0 if this instance has the same order as another.

      Throws
      • ClassCastException: @throws ClassCastException if another cannot be converted into something comparable to this instance.

    • equals

      public boolean equals(Object o)
      Description copied from class: Object
      Indicates whether some other object is "equal to" this one. The equals method implements an equivalence relation: It is reflexive: for any reference value x, x.equals(x) should return true. It is symmetric: for any reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true. It is transitive: for any reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true. It is consistent: for any reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the object is modified. For any non-null reference value x, x.equals(null) should return false. The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any reference values x and y, this method returns true if and only if x and y refer to the same object (x==y has the value true).
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Description copied from class: Object
      Returns a hash code value for the object. This method is supported for the benefit of hashtables such as those provided by java.util.Hashtable. The general contract of hashCode is: Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hashtables. As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
      Overrides:
      hashCode in class Object