- java.lang.Object
-
- java.lang.Boolean
-
- All Implemented Interfaces:
- Serializable, Comparable<Boolean>
public final class Boolean extends Object implements Serializable, Comparable<Boolean>
The Boolean class wraps a value of the primitive typeboolean
in an object. An object of typeBoolean
contains a single field whose type isboolean
.In addition, this class provides many methods for converting a
boolean
to aString
and aString
to aboolean
, as well as other constants and methods useful when dealing with aboolean
.- Since:
- JDK1.0
- See Also:
- Serialized Form
-
-
Field Summary
Fields Modifier and Type Field and Description static Boolean
FALSE
TheBoolean
object corresponding to the primitive valuefalse
.static Boolean
TRUE
TheBoolean
object corresponding to the primitive valuetrue
.static Class<Boolean>
TYPE
The Class object representing the primitive type boolean.
-
Constructor Summary
Constructors Constructor and Description Boolean(boolean value)
Allocates aBoolean
object representing thevalue
argument.Boolean(String s)
Allocates aBoolean
object representing the valuetrue
if the string argument is notnull
and is equal, ignoring case, to the string"true"
.
-
Method Summary
Methods Modifier and Type Method and Description boolean
booleanValue()
Returns the value of thisBoolean
object as a boolean primitive.static int
compare(boolean x, boolean y)
Compares twoboolean
values.int
compareTo(Boolean b)
Compares thisBoolean
instance with another.boolean
equals(Object obj)
Returnstrue
if and only if the argument is notnull
and is aBoolean
object that represents the sameboolean
value as this object.static boolean
getBoolean(String name)
Returnstrue
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 thisBoolean
object.static boolean
parseBoolean(String s)
Parses the string argument as a boolean.String
toString()
Returns aString
object representing this Boolean's value.static String
toString(boolean b)
Returns aString
object representing the specified boolean.static Boolean
valueOf(boolean b)
Returns aBoolean
instance representing the specifiedboolean
value.static Boolean
valueOf(String s)
Returns aBoolean
with a value represented by the specified string.
-
-
-
Field Detail
-
TRUE
public static final Boolean TRUE
TheBoolean
object corresponding to the primitive valuetrue
.
-
FALSE
public static final Boolean FALSE
TheBoolean
object corresponding to the primitive valuefalse
.
-
-
Constructor Detail
-
Boolean
public Boolean(boolean value)
Allocates aBoolean
object representing thevalue
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.- Parameters:
value
- the value of theBoolean
.
-
Boolean
public Boolean(String s)
Allocates aBoolean
object representing the valuetrue
if the string argument is notnull
and is equal, ignoring case, to the string"true"
. Otherwise, allocate aBoolean
object representing the valuefalse
. Examples:new Boolean("True")
produces aBoolean
object that representstrue
.
new Boolean("yes")
produces aBoolean
object that representsfalse
.- Parameters:
s
- the string to be converted to aBoolean
.
-
-
Method Detail
-
parseBoolean
public static boolean parseBoolean(String s)
Parses the string argument as a boolean. Theboolean
returned represents the valuetrue
if the string argument is notnull
and is equal, ignoring case, to the string"true"
.Example:
Boolean.parseBoolean("True")
returnstrue
.
Example:Boolean.parseBoolean("yes")
returnsfalse
.- Parameters:
s
- theString
containing the boolean representation to be parsed- Returns:
- the boolean represented by the string argument
- Since:
- 1.5
-
booleanValue
public boolean booleanValue()
Returns the value of thisBoolean
object as a boolean primitive.- Returns:
- the primitive
boolean
value of this object.
-
valueOf
public static Boolean valueOf(boolean b)
Returns aBoolean
instance representing the specifiedboolean
value. If the specifiedboolean
value istrue
, this method returnsBoolean.TRUE
; if it isfalse
, this method returnsBoolean.FALSE
. If a newBoolean
instance is not required, this method should generally be used in preference to the constructorBoolean(boolean)
, as this method is likely to yield significantly better space and time performance.- Parameters:
b
- a boolean value.- Returns:
- a
Boolean
instance representingb
. - Since:
- 1.4
-
valueOf
public static Boolean valueOf(String s)
Returns aBoolean
with a value represented by the specified string. TheBoolean
returned represents a true value if the string argument is notnull
and is equal, ignoring case, to the string"true"
.- Parameters:
s
- a string.- Returns:
- the
Boolean
value represented by the string.
-
toString
public static String toString(boolean b)
Returns aString
object representing the specified boolean. If the specified boolean istrue
, then the string"true"
will be returned, otherwise the string"false"
will be returned.- Parameters:
b
- the boolean to be converted- Returns:
- the string representation of the specified
boolean
- Since:
- 1.4
-
toString
public String toString()
Returns aString
object representing this Boolean's value. If this object represents the valuetrue
, a string equal to"true"
is returned. Otherwise, a string equal to"false"
is returned.
-
hashCode
public int hashCode()
Returns a hash code for thisBoolean
object.- Overrides:
hashCode
in classObject
- Returns:
- the integer
1231
if this object representstrue
; returns the integer1237
if this object representsfalse
. - See Also:
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
-
equals
public boolean equals(Object obj)
Returnstrue
if and only if the argument is notnull
and is aBoolean
object that represents the sameboolean
value as this object.- Overrides:
equals
in classObject
- Parameters:
obj
- the object to compare with.- Returns:
true
if the Boolean objects represent the same value;false
otherwise.- See Also:
Object.hashCode()
,HashMap
-
getBoolean
public static boolean getBoolean(String name)
Returnstrue
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 throughgetProperty
, a method defined by theSystem
class.If there is no property with the specified name, or if the specified name is empty or null, then
false
is returned.- Parameters:
name
- the system property name.- Returns:
- the
boolean
value of the system property. - See Also:
System.getProperty(java.lang.String)
,System.getProperty(java.lang.String, java.lang.String)
-
compareTo
public int compareTo(Boolean b)
Compares thisBoolean
instance with another.- Specified by:
compareTo
in interfaceComparable<Boolean>
- Parameters:
b
- theBoolean
instance to be compared- Returns:
- zero if this object represents the same boolean value as the argument; a positive value if this object represents true and the argument represents false; and a negative value if this object represents false and the argument represents true
- Throws:
NullPointerException
- if the argument isnull
- Since:
- 1.5
- See Also:
Comparable
-
compare
public static int compare(boolean x, boolean y)
Compares twoboolean
values. The value returned is identical to what would be returned by:Boolean.valueOf(x).compareTo(Boolean.valueOf(y))
- Parameters:
x
- the firstboolean
to comparey
- the secondboolean
to compare- Returns:
- the value
0
ifx == y
; a value less than0
if!x && y
; and a value greater than0
ifx && !y
- Since:
- 1.7
-
-
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Document heeft de 11/06/2005 gemaakt, de laatste keer de 04/03/2020 gewijzigd
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