com.google.common.base

Class Objects

java.lang.Object

com.google.common.base.Objects

@GwtCompatible
public final class Objects
extends Object

Helper functions that can operate on any Object.

See the Guava User Guide on writing Object methods with Objects.

Since:

2.0

Author:

Laurence Gonsalves

Method Summary

Modifier and Type	Method and Description
static boolean	equal(Object a, Object b) Determines whether two possibly-null objects are equal.
static int	hashCode(Object... objects) Generates a hash code for multiple values.

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(@NullableDecl
                            Object a,
                            @NullableDecl
                            Object b)

Determines whether two possibly-null objects are equal. Returns:

• true if a and b are both null.
• true if a and b are both non-null and they are equal according to Object.equals(Object).
• false in all other situations.

This assumes that any non-null objects passed to this function conform to the equals() contract.

Note for Java 7 and later: This method should be treated as deprecated; use Objects.equals(java.lang.Object, java.lang.Object) instead.

hashCode

public static int hashCode(@NullableDecl
                           Object... objects)

Generates a hash code for multiple values. The hash code is generated by calling Arrays.hashCode(Object[]). Note that array arguments to this method, with the exception of a single Object array, do not get any special handling; their hash codes are based on identity and not contents.

This is useful for implementing Object.hashCode(). For example, in an object that has three properties, x, y, and z, one could write:

 public int hashCode() {
   return Objects.hashCode(getX(), getY(), getZ());
 }
 

Warning: When a single object is supplied, the returned hash code does not equal the hash code of that object.

Note for Java 7 and later: This method should be treated as deprecated; use Objects.hash(java.lang.Object...) instead.