Code:

package c1.s2;

/**
 * @author Mikalai Zaikin
 */
public class BinaryLiterals {

    // An 8-bit 'byte' value:
    byte aByte = 0b00100001;

    // A 16-bit 'short' value:
    short aShort = 0b0010001010001010;

    // Some 32-bit 'int' values:
    int anInt1 = 0b10100001010001011010000101000101;
    int anInt2 = 0b101;
    int anInt3 = 0B101; // The B can be upper or lower case.

    // A 64-bit 'long' value. Note the "L" suffix:
    long aLong = 0b1010000101000101101000010100010110100001010001011010000101000101L;

    double d1 = 0b0001;
    double d2 = 0b0001d; // COMPILATION ERROR: can only be of integer type !
    float f1 = 0b0001;
    float f2 = 0b0001f;  // COMPILATION ERROR: can only be of integer type !

}
						

Code:

package c1.s2;

/**
 * @author Mikalai Zaikin
 */
public class Underscores {

    long creditCardNumber = 1234_5678_9012_3456L;
    long socialSecurityNumber = 999_99_9999L;
    float pi = 3.14_15F;
    long hexBytes = 0xFF_EC_DE_5E;
    long hexWords = 0xCAFE_BABE;
    long maxLong = 0x7fff_ffff_ffff_ffffL;
    byte nybbles = 0b0010_0101;
    long bytes = 0b11010010_01101001_10010100_10010010;

    // VALID
    int x2 = 5_2;              // OK (decimal literal)
    int x4 = 5_______2;        // OK (decimal literal)
    int x7 = 0x5_2;            // OK (hexadecimal literal)
    int x10 = 0B0_0_0;         // OK (binary literal)

    // INVALID
    float pi1 = 3_.1415F;      // Invalid; cannot put underscores adjacent to a decimal point
    float pi2 = 3._1415F;      // Invalid; cannot put underscores adjacent to a decimal point
    long ssn = 999_99_9999_L;  // Invalid; cannot put underscores prior to an L suffix
    int x3 = 52_;              // Invalid; cannot put underscores at the end of a literal
    int x5 = 0_x52;            // Invalid; cannot put underscores in the 0x radix prefix
    int x6 = 0x_52;            // Invalid; cannot put underscores at the beginning of a number
    int x8 = 0x52_;            // Invalid; cannot put underscores at the end of a number
    int x1 = _52;              // This is an identifier, not a numeric literal
}