java.lang.Boolean

All Implemented Interfaces:: Serializable, Comparable<Boolean>, Constable

public final class Boolean extends Object implements Serializable, Comparable<Boolean>, Constable

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.

This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

Since:

1.0

See Also:

Field Summary

Fields

Modifier and Type

Field

Description

static final Boolean

FALSE

The Boolean object corresponding to the primitive value false.

static final Boolean

TRUE

The Boolean object corresponding to the primitive value true.

static final Class<Boolean>

TYPE

The Class object representing the primitive type boolean.
Constructor Summary

Constructors

Constructor

Description

Boolean(boolean value)

Deprecated, for removal: This API element is subject to removal in a future version.
It is rarely appropriate to use this constructor.

Boolean(String s)

Deprecated, for removal: This API element is subject to removal in a future version.
It is rarely appropriate to use this constructor.
Method Summary

Modifier and Type

Method

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.

Optional<DynamicConstantDesc<Boolean>>

describeConstable()

Returns an Optional containing the nominal descriptor for this instance.

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, ignoring case, the string "true".

int

hashCode()

Returns a hash code for this Boolean object.

static int

hashCode(boolean value)

Returns a hash code for a boolean value; compatible with Boolean.hashCode().

static boolean

logicalAnd(boolean a, boolean b)

Returns the result of applying the logical AND operator to the specified boolean operands.

static boolean

logicalOr(boolean a, boolean b)

Returns the result of applying the logical OR operator to the specified boolean operands.

static boolean

logicalXor(boolean a, boolean b)

Returns the result of applying the logical XOR operator to the specified boolean operands.

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.

Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details
- 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 Details
- Boolean
  
  @Deprecated(since="9", forRemoval=true) public Boolean(boolean value)
  
  Deprecated, for removal: This API element is subject to removal in a future version.
  It is rarely appropriate to use this constructor. The static factory 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 the Boolean.
- Boolean
  
  @Deprecated(since="9", forRemoval=true) public Boolean(String s)
  
  Deprecated, for removal: This API element is subject to removal in a future version.
  It is rarely appropriate to use this constructor. Use 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 a Boolean.
Method Details
- 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 - the String 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 representing b.
  
  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.
  
  Overrides:
  
  toString in class Object
  
  Returns:
  
  a string representation of this object.
- hashCode
  public int hashCode()
  
  Returns a hash code for this Boolean object.
  
  Overrides:
  
  hashCode in class Object
  
  Returns:
  
  the integer 1231 if this object represents true; returns the integer 1237 if this object represents false.
  
  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 class Object
  
  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 as System.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 interface Comparable<Boolean>
  
  Parameters:
  
  b - the Boolean 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 is null
  
  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 first boolean to compare
  
  y - the second boolean to compare
  
  Returns:
  
  the value 0 if x == y; a value less than 0 if !x && y; and a value greater than 0 if x && !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 and b
  
  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 and b
  
  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 and b
  
  Since:
  
  1.8
  
  See Also:
  
  BinaryOperator
- describeConstable
  
  public Optional<DynamicConstantDesc<Boolean>> describeConstable()
  
  Returns an Optional containing the nominal descriptor for this instance.
  
  Specified by:
  
  describeConstable in interface Constable
  
  Returns:
  
  an Optional describing the Boolean instance
  
  Since:
  
  15

Class Boolean

Field Summary

Constructor Summary

Method Summary

Methods declared in class java.lang.Object

Field Details

TRUE

FALSE

TYPE

Constructor Details

Boolean

Boolean

Method Details

parseBoolean

booleanValue

valueOf

valueOf

toString

toString

hashCode

hashCode

equals

getBoolean

compareTo

compare

logicalAnd

logicalOr

logicalXor

describeConstable