|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectcom.google.gdata.util.common.base.Objects
@GwtCompatible public final class Objects
Helper functions that can operate on any Object
.
Nested Class Summary | |
---|---|
static class |
Objects.ToStringHelper
Helper class for generating consistent toString across ads/api pojos. This class is made to support toStringHelper(Object) . |
Method Summary | ||
---|---|---|
static boolean |
deepEquals(java.lang.Object a,
java.lang.Object b)
Determines if two objects are equal as determined by Object.equals(Object) , or "deeply equal" if both are arrays. |
|
static int |
deepHashCode(java.lang.Object obj)
Determines the hash code of an object, returning a hash code based on the array's "deep contents" if the object is an array. |
|
static java.lang.String |
deepToString(java.lang.Object obj)
Determines the string representation of an object, or the "deep contents of the array if the obj is an array. |
|
static boolean |
equal(java.lang.Object a,
java.lang.Object b)
Determines whether two possibly-null objects are equal. |
|
static
|
firstNonNull(T first,
T second)
Returns the first of two given parameters that is not null , if
either is, or otherwise throws a NullPointerException . |
|
static int |
hashCode(java.lang.Object... objects)
Generates a hash code for multiple values. |
|
static
|
nonNull(T obj)
Checks that the specified object is not null . |
|
static
|
nonNull(T obj,
java.lang.String message)
Checks that the specified object is not null . |
|
static Objects.ToStringHelper |
toStringHelper(java.lang.Object object)
Creates an instance of Objects.ToStringHelper . |
Methods inherited from class java.lang.Object |
---|
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Method Detail |
---|
public static boolean equal(java.lang.Object a, java.lang.Object b)
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.
public static int hashCode(java.lang.Object... objects)
Arrays.hashCode(Object[])
.
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.
public static Objects.ToStringHelper toStringHelper(java.lang.Object object)
Objects.ToStringHelper
.
This is helpful for implementing Object.toString()
. For
example, in an object that contains two member variables, x
,
and y
, one could write:
public class ClassName { public String toString() { return Objects.toStringHelper(this) .add("x", x) .add("y", y) .toString(); } }Assuming the values of
x
and y
are 1 and 2,
this code snippet returns the string "ClassName{x=1, y=2}".
public static <T> T nonNull(T obj)
null
.
obj
- the object to check for nullness
obj
if not null.
java.lang.NullPointerException
- if obj
is null.public static <T> T nonNull(T obj, java.lang.String message)
null
.
obj
- the object to check for nullnessmessage
- exception message used in the event that a NullPointerException
is thrown
obj
if not null
java.lang.NullPointerException
- if obj
is nullpublic static <T> T firstNonNull(T first, T second)
null
, if
either is, or otherwise throws a NullPointerException
.
first
if first
is not null
, or
second
if first
is null
and second
is
not null
java.lang.NullPointerException
- if both first
and second
were
null
public static boolean deepEquals(java.lang.Object a, java.lang.Object b)
Object.equals(Object)
, or "deeply equal" if both are arrays.
If both objects are null, true
is returned. If only one is null,
false
is returned. If both objects are arrays, the corresponding
Arrays.deepEquals(Object[], Object[])
, or
Arrays.equals(int[], int[])
or the like are called to determine
equality. Otherwise, a.equals(b)
is returned.
Note that this method does not "deeply" compare the fields of the objects.
public static int deepHashCode(java.lang.Object obj)
If obj
is null, 0 is returned. If obj
is an array, the
corresponding Arrays.deepHashCode(Object[])
, or
Arrays.hashCode(int[])
or the like is used to calculate the hash
code. If obj
isn't null or an array, obj.hashCode()
is
returned.
public static java.lang.String deepToString(java.lang.Object obj)
obj
is an array.
If obj
is null, "null"
is returned; if obj
is an
array, the corresponding Arrays.deepToString(Object[])
,
Arrays.toString(int[])
or the like is used to generate the string.
If obj
isn't null or an array, obj.toString()
is returned.
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |