Here you can find the source of doubleToLongBits(final double d)

Parameter | Description |
---|---|

f | an input floating-point number |

public static final long doubleToLongBits(final double d)

//package com.java2s; public class Main { /**/* w w w. ja va 2 s. c o m*/ * Returns the representation of the specified floating-point * value according to the IEEE 754 floating-point "double format" * bit layout, after first mapping -0.0 to 0.0. This method is * identical to Double.doubleToLongBits(double) except that an integer * value of 0 is returned for a floating-point value of * -0.0d. This is done for the purpose of computing a hash code * that satisfies the contract of hashCode() and equals(). The * equals() method in each vecmath class does a pair-wise "==" * test on each floating-point field in the class (e.g., x, y, and * z for a Tuple3d). Since 0.0d == -0.0d returns true, * we must also return the same hash code for two objects, one of * which has a field with a value of -0.0d and the other of which * has a corresponding field with a value of 0.0d. * * @param f an input floating-point number * @return the integer bits representing that floating-point * number, after first mapping -0.0f to 0.0f */ public static final long doubleToLongBits(final double d) { // Check for +0 or -0 return ((d == 0.0d) ? 0l :Double.doubleToLongBits(d)); } }