| java.lang.Object | |
| ↳ | com.facebook.common.internal.Objects |
Helper functions that can operate on any Object.
See the Guava User Guide on writing
Object methods with Objects.
| Nested Classes | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| class | Objects.ToStringHelper | Support class for toStringHelper(Class>). |
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| Public Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| static boolean |
equal(Object a, Object b)
Determines whether two possibly-null objects are equal.
| ||||||||||
| static <T> T |
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(Object... objects)
Generates a hash code for multiple values.
| ||||||||||
| static Objects.ToStringHelper |
toStringHelper(String className)
Creates an instance of
Objects.ToStringHelper in the same manner as
toStringHelper(Object), but using className instead
of using an instance's getClass(). | ||||||||||
| static Objects.ToStringHelper |
toStringHelper(Object self)
Creates an instance of
Objects.ToStringHelper. | ||||||||||
| static Objects.ToStringHelper |
toStringHelper(Class<?> clazz)
Creates an instance of
Objects.ToStringHelper in the same manner as
toStringHelper(Object), but using the name of clazz
instead of using an instance's getClass(). | ||||||||||
|
[Expand]
Inherited Methods | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
From class
java.lang.Object
| |||||||||||
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 equals(Object).
false in all other situations.
This assumes that any non-null objects passed to this function conform
to the equals() contract.
Returns the first of two given parameters that is not null, if
either is, or otherwise throws a NullPointerException.
Note: if first is represented as an Optional,
this can be accomplished with
Optional#or(Object) first.or(second).
That approach also allows for lazy evaluation of the fallback instance,
using Optional#or(Supplier) first.or(Supplier).
first if first is not null, or
second if first is null and second is
not null| NullPointerException | if both first and second were
null |
|---|
Generates a hash code for multiple values. The hash code is generated by
calling 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 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.
Creates an instance of Objects.ToStringHelper in the same manner as
toStringHelper(Object), but using className instead
of using an instance's getClass().
| className | the name of the instance type |
|---|
Creates an instance of Objects.ToStringHelper.
This is helpful for implementing toString().
Specification by example:
// Returns "ClassName{"
Objects.toStringHelper(this)
.toString();
// Returns "ClassName{x=1}"
Objects.toStringHelper(this)
.add("x", 1)
.toString();
// Returns "MyObject{x=1}"
Objects.toStringHelper("MyObject")
.add("x", 1)
.toString();
// Returns "ClassName{x=1, y=foo}"
Objects.toStringHelper(this)
.add("x", 1)
.add("y", "foo")
.toString();
// Returns "ClassName{x=1}"
Objects.toStringHelper(this)
.omitNullValues()
.add("x", 1)
.add("y", null)
.toString();
}}
Note that in GWT, class names are often obfuscated.
| self | the object to generate the string for (typically this),
used only for its class name |
|---|
Creates an instance of Objects.ToStringHelper in the same manner as
toStringHelper(Object), but using the name of clazz
instead of using an instance's getClass().
Note that in GWT, class names are often obfuscated.
| clazz | the Class of the instance |
|---|