public final class

Boolean

extends Object
implements Serializable Comparable<T>
java.lang.Object
   ↳ java.lang.Boolean

Class Overview

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.

Summary

Fields
public static final Boolean FALSE The Boolean object corresponding to the primitive value false.
public static final Boolean TRUE The Boolean object corresponding to the primitive value true.
public static final Class<Boolean> TYPE The Class object representing the primitive type boolean.
Public Constructors
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".
Public Methods
boolean booleanValue()
Returns the value of this Boolean object as a boolean primitive.
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.
static String toString(boolean b)
Returns a String object representing the specified boolean.
String toString()
Returns a String object representing this Boolean's value.
static Boolean valueOf(String s)
Returns a Boolean with a value represented by the specified string.
static Boolean valueOf(boolean b)
Returns a Boolean instance representing the specified boolean value.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.lang.Comparable

Fields

public static final Boolean FALSE

The Boolean object corresponding to the primitive value false.

public static final Boolean TRUE

The Boolean object corresponding to the primitive value true.

public static final Class<Boolean> TYPE

The Class object representing the primitive type boolean.

Public Constructors

public Boolean (boolean value)

Allocates a 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.

Parameters
value the value of the Boolean.

public 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". 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.

Parameters
s the string to be converted to a Boolean.

Public Methods

public boolean booleanValue ()

Returns the value of this Boolean object as a boolean primitive.

Returns
  • the primitive boolean value of this object.

public int compareTo (Boolean b)

Compares this Boolean instance with another.

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
See Also

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.

Parameters
obj the object to compare with.
Returns
  • true if the Boolean objects represent the same value; false otherwise.

public 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". (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.

Parameters
name the system property name.
Returns
  • the boolean value of the system property.
See Also

public int hashCode ()

Returns a hash code for this Boolean object.

Returns
  • the integer 1231 if this object represents true; returns the integer 1237 if this object represents false.

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".

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

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

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.

Returns
  • a string representation of this object.

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".

Parameters
s a string.
Returns
  • the Boolean value represented by the string.

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.