public final class Boolean extends Object implements Serializable, Comparable<Boolean>
boolean
in an object. An object of
type Boolean
contains a single field whose type is boolean
.
In addition, this class provides many methods for converting a boolean
to a
String
and a String
to a boolean
, as well as other constants and methods
useful when dealing with a boolean
.
Modifier and Type | Field and Description |
---|---|
static Boolean |
FALSE
The
Boolean object corresponding to the primitive value false . |
static Boolean |
TRUE
The
Boolean object corresponding to the primitive value true . |
Constructor and Description |
---|
Boolean(boolean value)
Allocates a
Boolean object representing the value argument. |
Boolean(String s)
Allocates a
Boolean object representing the value true if the string argument is
not null and is equal, ignoring case, to the string "true" . |
Modifier and Type | Method and Description |
---|---|
boolean |
booleanValue()
Returns the value of this
Boolean object as a boolean primitive. |
static int |
compare(boolean x,
boolean y)
Compares two
boolean values. |
int |
compareTo(Boolean b)
Compares this
Boolean instance with another. |
boolean |
equals(Object obj)
Returns
true if and only if the argument is not null and is a Boolean
object that represents the same boolean value as this object. |
static boolean |
getBoolean(String name)
Returns
true if and only if the system property named by the argument exists and is equal
to the string "true" . |
int |
hashCode()
Returns a hash code for this
Boolean object. |
static boolean |
parseBoolean(String s)
Parses the string argument as a boolean.
|
String |
toString()
Returns a
String object representing this Boolean's value. |
static String |
toString(boolean b)
Returns a
String object representing the specified boolean. |
static Boolean |
valueOf(boolean b)
Returns a
Boolean instance representing the specified boolean value. |
static Boolean |
valueOf(String s)
Returns a
Boolean with a value represented by the specified string. |
public static final Boolean FALSE
Boolean
object corresponding to the primitive value false
.public static final Boolean TRUE
Boolean
object corresponding to the primitive value true
.public Boolean(boolean value)
Boolean
object representing the value
argument.
Note: It is rarely appropriate to use this constructor. Unless a new instance is
required, the static factory valueOf(boolean)
is generally a better choice. It is likely
to yield significantly better space and time performance.
value
- the value of the Boolean
.public Boolean(@Nullable String s)
Boolean
object representing the value true
if the string argument is
not null
and is equal, ignoring case, to the string "true"
. Otherwise, allocate a
Boolean
object representing the value false
. Examples:
new Boolean("True")
produces a Boolean
object that represents true
.
new Boolean("yes")
produces a Boolean
object that represents false
.
s
- the string to be converted to a Boolean
.public boolean booleanValue()
Boolean
object as a boolean primitive.boolean
value of this object.public static int compare(boolean x, boolean y)
boolean
values. The value returned is identical to what would be returned
by:
Boolean.valueOf(x).compareTo(Boolean.valueOf(y))
x
- the first boolean
to comparey
- the second boolean
to compare0
if x == y
; a value less than 0
if !x && y
;
and a value greater than 0
if x && !y
public int compareTo(Boolean b)
Boolean
instance with another.compareTo
in interface Comparable<Boolean>
b
- the Boolean
instance to be comparedNullPointerException
- if the argument is null
Comparable
public boolean equals(@Nullable Object obj)
true
if and only if the argument is not null
and is a Boolean
object that represents the same boolean
value as this object.equals
in class Object
obj
- the object to compare with.true
if the Boolean objects represent the same value; false
otherwise.Object.hashCode()
,
HashMap
public static boolean getBoolean(String name)
true
if and only if the system property named by the argument exists and is equal
to the string "true"
. (Beginning with version 1.0.2 of the
JavaTM platform, the test of this string is case insensitive.) A system
property is accessible through getProperty
, a method defined by the System
class.
If there is no property with the specified name, or if the specified name is empty or null, then
false
is returned.
name
- the system property name.boolean
value of the system property.System.getProperty(java.lang.String)
,
System.getProperty(java.lang.String, java.lang.String)
public int hashCode()
Boolean
object.hashCode
in class Object
1231
if this object represents true
; returns the integer
1237
if this object represents false
.Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
public static boolean parseBoolean(@Nullable String s)
boolean
returned represents the value
true
if the string argument is not null
and is equal, ignoring case, to the
string "true"
.
Example: Boolean.parseBoolean("True")
returns true
.
Example: Boolean.parseBoolean("yes")
returns false
.
s
- the String
containing the boolean representation to be parsedpublic String toString()
String
object representing this Boolean's value. If this object represents the
value true
, a string equal to "true"
is returned. Otherwise, a string equal to
"false"
is returned.public static String toString(boolean b)
String
object representing the specified boolean. If the specified boolean is
true
, then the string "true"
will be returned, otherwise the string
"false"
will be returned.b
- the boolean to be convertedboolean
public static Boolean valueOf(boolean b)
Boolean
instance representing the specified boolean
value. If the
specified boolean
value is true
, this method returns Boolean.TRUE
; if it
is false
, this method returns Boolean.FALSE
. If a new Boolean
instance is
not required, this method should generally be used in preference to the constructor
Boolean(boolean)
, as this method is likely to yield significantly better space and time
performance.b
- a boolean value.Boolean
instance representing b
.public static Boolean valueOf(@Nullable String s)
Boolean
with a value represented by the specified string. The Boolean
returned represents a true value if the string argument is not null
and is equal,
ignoring case, to the string "true"
.s
- a string.Boolean
value represented by the string.