org.apache.fop.util

## Class CompareUtil

- java.lang.Object
- - org.apache.fop.util.CompareUtil

-     public final class CompareUtil
      extends java.lang.Object

  A utility class that provides helper methods for implementing equals and hashCode.

- - ### Method Summary

    All Methods Static Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `static boolean` | `equal(double n1, double n2)` Compares two numbers for equality.
    `static boolean` | `equal(java.lang.Object o1, java.lang.Object o2)` Compares two objects for equality.
    `static int` | `getHashCode(double number)` Returns a hash code for the given number.
    `static int` | `getHashCode(java.lang.Object object)` Returns the hash code of the given object.

    - ### Methods inherited from class java.lang.Object

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

- - ### Method Detail

    - #### equal

          public static boolean equal(java.lang.Object o1,
                                      java.lang.Object o2)

      Compares two objects for equality. In order to prevent lock-ordering deadlocks the following strategy is used: when two non null objects are passed to the method, the comparison is done by calling the `Object.equals(Object)` method of the object with the lower hash code (`System.identityHashCode(Object)`); in the rare case that two different objects have the same hash code, a lock is used.
      Parameters:
        `o1` - an object
        `o2` - another object
      Returns:
        true if either o1 and o2 are null or if o1.equals(o2)

    - #### getHashCode

          public static int getHashCode(java.lang.Object object)

      Returns the hash code of the given object.
      Parameters:
        `object` - an object
      Returns:
        object.hashCode(), or 0 if object is null

    - #### equal

          public static boolean equal(double n1,
                                      double n2)

      Compares two numbers for equality. Uses the same comparison algorithm as the `Double.equals(Object)` method.
      Parameters:
        `n1` - a number
        `n2` - another number
      Returns:
        true if the two numbers are equal, false otherwise

    - #### getHashCode

          public static int getHashCode(double number)

      Returns a hash code for the given number. Applies the same algorithm as the `Double.hashCode()` method.
      Parameters:
        `number` - a number
      Returns:
        a hash code for that number

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