Class Boolean
- 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 type 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
.
- Since:
- 1.0
- See Also:
- Serialized Form
Field Summary
Modifier and Type | Field | Description |
---|---|---|
static Boolean | FALSE | The |
static Boolean | TRUE | The |
static Class<Boolean> | TYPE | The Class object representing the primitive type boolean. |
Constructor Summary
Constructor | Description |
---|---|
Boolean(boolean value) | Deprecated. It is rarely appropriate to use this constructor. |
Boolean(String s) | Deprecated. It is rarely appropriate to use this constructor. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
boolean | booleanValue() | Returns the value of this |
static int | compare(boolean x,
boolean y) | Compares two |
int | compareTo(Boolean b) | Compares this |
boolean | equals(Object obj) | Returns |
static boolean | getBoolean(String name) | Returns |
int | hashCode() | Returns a hash code for this |
static int | hashCode(boolean value) | Returns a hash code for a |
static boolean | logicalAnd(boolean a,
boolean b) | Returns the result of applying the logical AND operator to the specified |
static boolean | logicalOr(boolean a,
boolean b) | Returns the result of applying the logical OR operator to the specified |
static boolean | logicalXor(boolean a,
boolean b) | Returns the result of applying the logical XOR operator to the specified |
static boolean | parseBoolean(String s) | Parses the string argument as a boolean. |
String | toString() | Returns a |
static String | toString(boolean b) | Returns a |
static Boolean | valueOf(boolean b) | Returns a |
static Boolean | valueOf(String s) | Returns a |
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Field Detail
TRUE
public static final Boolean TRUE
The Boolean
object corresponding to the primitive value true
.
FALSE
public static final Boolean FALSE
The Boolean
object corresponding to the primitive value false
.
TYPE
public static final Class<Boolean> TYPE
The Class object representing the primitive type boolean.
- Since:
- 1.1
Constructor Detail
Boolean
@Deprecated(since="9") public Boolean(boolean value)
valueOf(boolean)
is generally a better choice, as it is likely to yield significantly better space and time performance. Also consider using the final fields TRUE
and FALSE
if possible.Allocates a Boolean
object representing the value
argument.
- Parameters:
-
value
- the value of theBoolean
.
Boolean
@Deprecated(since="9") public Boolean(String s)
parseBoolean(String)
to convert a string to a boolean
primitive, or use valueOf(String)
to convert a string to a Boolean
object.Allocates a Boolean
object representing the value true
if the string argument is not null
and is equal, ignoring case, to the string "true"
. Otherwise, allocates a Boolean
object representing the value false
.
- 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. The boolean
returned represents the value true
if the string argument is not null
and is equal, ignoring case, to the string "true"
. Otherwise, a false value is returned, including for a null argument.
Example: Boolean.parseBoolean("True")
returns true
.
Example: Boolean.parseBoolean("yes")
returns false
.
- 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 this Boolean
object as a boolean primitive.
- Returns:
- the primitive
boolean
value of this object.
valueOf
public static Boolean valueOf(boolean b)
Returns a 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.
- Parameters:
-
b
- a boolean value. - Returns:
- a
Boolean
instance representingb
. - Since:
- 1.4
valueOf
public static Boolean valueOf(String s)
Returns a 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"
. Otherwise, a false value is returned, including for a null argument.
- Parameters:
-
s
- a string. - Returns:
- the
Boolean
value represented by the string.
toString
public static String toString(boolean b)
Returns a 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.
- Parameters:
-
b
- the boolean to be converted - Returns:
- the string representation of the specified
boolean
- Since:
- 1.4
toString
public String toString()
Returns a 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.
hashCode
public int hashCode()
Returns a hash code for this Boolean
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)
hashCode
public static int hashCode(boolean value)
Returns a hash code for a boolean
value; compatible with Boolean.hashCode()
.
- Parameters:
-
value
- the value to hash - Returns:
- a hash code value for a
boolean
value. - Since:
- 1.8
equals
public 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.
- 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)
Returns true
if and only if the system property named by the argument exists and is equal to, ignoring case, the string "true"
. 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.
- Parameters:
-
name
- the system property name. - Returns:
- the
boolean
value of the system property. - Throws:
-
SecurityException
- for the same reasons asSystem.getProperty
- See Also:
-
System.getProperty(java.lang.String)
,System.getProperty(java.lang.String, java.lang.String)
compareTo
public int compareTo(Boolean b)
Compares this Boolean
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 two boolean
values. The value returned is identical to what would be returned by:
Boolean.valueOf(x).compareTo(Boolean.valueOf(y))
- Parameters:
-
x
- the firstboolean
to compare -
y
- 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
logicalAnd
public static boolean logicalAnd(boolean a, boolean b)
Returns the result of applying the logical AND operator to the specified boolean
operands.
- Parameters:
-
a
- the first operand -
b
- the second operand - Returns:
- the logical AND of
a
andb
- Since:
- 1.8
- See Also:
BinaryOperator
logicalOr
public static boolean logicalOr(boolean a, boolean b)
Returns the result of applying the logical OR operator to the specified boolean
operands.
- Parameters:
-
a
- the first operand -
b
- the second operand - Returns:
- the logical OR of
a
andb
- Since:
- 1.8
- See Also:
BinaryOperator
logicalXor
public static boolean logicalXor(boolean a, boolean b)
Returns the result of applying the logical XOR operator to the specified boolean
operands.
- Parameters:
-
a
- the first operand -
b
- the second operand - Returns:
- the logical XOR of
a
andb
- Since:
- 1.8
- See Also:
BinaryOperator