java.lang
Class Boolean

java.lang.Object sample code for java.lang.Object definition code for java.lang.Object 
  extended by java.lang.Boolean
All Implemented Interfaces:
Serializable sample code for java.io.Serializable definition code for java.io.Serializable , Comparable sample code for java.lang.Comparable definition code for java.lang.Comparable <Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean >

public final class Boolean
extends Object sample code for java.lang.Object definition code for java.lang.Object
implements Serializable sample code for java.io.Serializable definition code for java.io.Serializable , Comparable sample code for java.lang.Comparable definition code for java.lang.Comparable <Boolean sample code for java.lang.Boolean definition code for java.lang.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:
JDK1.0
See Also:
Serialized Form

Field Summary
static Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean FALSE sample code for java.lang.Boolean.FALSE definition code for java.lang.Boolean.FALSE
          The Boolean object corresponding to the primitive value false.
static Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean TRUE sample code for java.lang.Boolean.TRUE definition code for java.lang.Boolean.TRUE
          The Boolean object corresponding to the primitive value true.
static Class sample code for java.lang.Class definition code for java.lang.Class <Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean > TYPE sample code for java.lang.Boolean.TYPE definition code for java.lang.Boolean.TYPE
          The Class object representing the primitive type boolean.
 
Constructor Summary
Boolean sample code for java.lang.Boolean.Boolean(boolean) definition code for java.lang.Boolean.Boolean(boolean) (boolean value)
          Allocates a Boolean object representing the value argument.
Boolean sample code for java.lang.Boolean.Boolean(java.lang.String) definition code for java.lang.Boolean.Boolean(java.lang.String) (String sample code for java.lang.String definition code for java.lang.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".
 
Method Summary
 boolean booleanValue sample code for java.lang.Boolean.booleanValue() definition code for java.lang.Boolean.booleanValue() ()
          Returns the value of this Boolean object as a boolean primitive.
 int compareTo sample code for java.lang.Boolean.compareTo(java.lang.Boolean) definition code for java.lang.Boolean.compareTo(java.lang.Boolean) (Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean  b)
          Compares this Boolean instance with another.
 boolean equals sample code for java.lang.Boolean.equals(java.lang.Object) definition code for java.lang.Boolean.equals(java.lang.Object) (Object sample code for java.lang.Object definition code for java.lang.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 sample code for java.lang.Boolean.getBoolean(java.lang.String) definition code for java.lang.Boolean.getBoolean(java.lang.String) (String sample code for java.lang.String definition code for java.lang.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 sample code for java.lang.Boolean.hashCode() definition code for java.lang.Boolean.hashCode() ()
          Returns a hash code for this Boolean object.
static boolean parseBoolean sample code for java.lang.Boolean.parseBoolean(java.lang.String) definition code for java.lang.Boolean.parseBoolean(java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  s)
          Parses the string argument as a boolean.
 String sample code for java.lang.String definition code for java.lang.String toString sample code for java.lang.Boolean.toString() definition code for java.lang.Boolean.toString() ()
          Returns a String object representing this Boolean's value.
static String sample code for java.lang.String definition code for java.lang.String toString sample code for java.lang.Boolean.toString(boolean) definition code for java.lang.Boolean.toString(boolean) (boolean b)
          Returns a String object representing the specified boolean.
static Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean valueOf sample code for java.lang.Boolean.valueOf(boolean) definition code for java.lang.Boolean.valueOf(boolean) (boolean b)
          Returns a Boolean instance representing the specified boolean value.
static Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean valueOf sample code for java.lang.Boolean.valueOf(java.lang.String) definition code for java.lang.Boolean.valueOf(java.lang.String) (String sample code for java.lang.String definition code for java.lang.String  s)
          Returns a Boolean with a value represented by the specified String.
 
Methods inherited from class java.lang.Object sample code for java.lang.Object definition code for java.lang.Object
clone sample code for java.lang.Object.clone() definition code for java.lang.Object.clone() , finalize sample code for java.lang.Object.finalize() definition code for java.lang.Object.finalize() , getClass sample code for java.lang.Object.getClass() definition code for java.lang.Object.getClass() , notify sample code for java.lang.Object.notify() definition code for java.lang.Object.notify() , notifyAll sample code for java.lang.Object.notifyAll() definition code for java.lang.Object.notifyAll() , wait sample code for java.lang.Object.wait() definition code for java.lang.Object.wait() , wait sample code for java.lang.Object.wait(long) definition code for java.lang.Object.wait(long) , wait sample code for java.lang.Object.wait(long, int) definition code for java.lang.Object.wait(long, int)
 

Field Detail

TRUE sample code for java.lang.Boolean.TRUE

public static final Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean  TRUE
The Boolean object corresponding to the primitive value true.


FALSE sample code for java.lang.Boolean.FALSE

public static final Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean  FALSE
The Boolean object corresponding to the primitive value false.


TYPE sample code for java.lang.Boolean.TYPE

public static final Class sample code for java.lang.Class definition code for java.lang.Class <Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean > TYPE
The Class object representing the primitive type boolean.

Since:
JDK1.1
Constructor Detail

Boolean sample code for java.lang.Boolean(boolean) definition code for java.lang.Boolean(boolean)

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) sample code for java.lang.Boolean.valueOf(boolean) definition code for java.lang.Boolean.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.

Boolean sample code for java.lang.Boolean(java.lang.String) definition code for java.lang.Boolean(java.lang.String)

public Boolean(String sample code for java.lang.String definition code for java.lang.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.
Method Detail

parseBoolean sample code for java.lang.Boolean.parseBoolean(java.lang.String) definition code for java.lang.Boolean.parseBoolean(java.lang.String)

public static boolean parseBoolean(String sample code for java.lang.String definition code for java.lang.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".

Parameters:
s - the String containing the boolean representation to be parsed
Returns:
the boolean represented by the string argument
Since:
1.5

booleanValue sample code for java.lang.Boolean.booleanValue() definition code for java.lang.Boolean.booleanValue()

public boolean booleanValue()
Returns the value of this Boolean object as a boolean primitive.

Returns:
the primitive boolean value of this object.

valueOf sample code for java.lang.Boolean.valueOf(boolean) definition code for java.lang.Boolean.valueOf(boolean)

public static Boolean sample code for java.lang.Boolean definition code for java.lang.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) sample code for java.lang.Boolean.Boolean(boolean) definition code for java.lang.Boolean.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 sample code for java.lang.Boolean.valueOf(java.lang.String) definition code for java.lang.Boolean.valueOf(java.lang.String)

public static Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean  valueOf(String sample code for java.lang.String definition code for java.lang.String  s)
Returns a Boolean with a value represented by the specified String. 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.valueOf("True") returns true.
Example: Boolean.valueOf("yes") returns false.

Parameters:
s - a string.
Returns:
the Boolean value represented by the string.

toString sample code for java.lang.Boolean.toString(boolean) definition code for java.lang.Boolean.toString(boolean)

public static String sample code for java.lang.String definition code for java.lang.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 sample code for java.lang.Boolean.toString() definition code for java.lang.Boolean.toString()

public String sample code for java.lang.String definition code for java.lang.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 sample code for java.lang.Object.toString() definition code for java.lang.Object.toString() in class Object sample code for java.lang.Object definition code for java.lang.Object
Returns:
a string representation of this object.

hashCode sample code for java.lang.Boolean.hashCode() definition code for java.lang.Boolean.hashCode()

public int hashCode()
Returns a hash code for this Boolean object.

Overrides:
hashCode sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() in class Object sample code for java.lang.Object definition code for java.lang.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) sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) , Hashtable sample code for java.util.Hashtable definition code for java.util.Hashtable

equals sample code for java.lang.Boolean.equals(java.lang.Object) definition code for java.lang.Boolean.equals(java.lang.Object)

public boolean equals(Object sample code for java.lang.Object definition code for java.lang.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 sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) in class Object sample code for java.lang.Object definition code for java.lang.Object
Parameters:
obj - the object to compare with.
Returns:
true if the Boolean objects represent the same value; false otherwise.
See Also:
Object.hashCode() sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , Hashtable sample code for java.util.Hashtable definition code for java.util.Hashtable

getBoolean sample code for java.lang.Boolean.getBoolean(java.lang.String) definition code for java.lang.Boolean.getBoolean(java.lang.String)

public static boolean getBoolean(String sample code for java.lang.String definition code for java.lang.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:
System.getProperty(java.lang.String) sample code for java.lang.System.getProperty(java.lang.String) definition code for java.lang.System.getProperty(java.lang.String) , System.getProperty(java.lang.String, java.lang.String) sample code for java.lang.System.getProperty(java.lang.String, java.lang.String) definition code for java.lang.System.getProperty(java.lang.String, java.lang.String)

compareTo sample code for java.lang.Boolean.compareTo(java.lang.Boolean) definition code for java.lang.Boolean.compareTo(java.lang.Boolean)

public int compareTo(Boolean sample code for java.lang.Boolean definition code for java.lang.Boolean  b)
Compares this Boolean instance with another.

Specified by:
compareTo sample code for java.lang.Comparable.compareTo(T) definition code for java.lang.Comparable.compareTo(T) in interface Comparable sample code for java.lang.Comparable definition code for java.lang.Comparable <Boolean sample code for java.lang.Boolean definition code for java.lang.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 sample code for java.lang.NullPointerException definition code for java.lang.NullPointerException - if the argument is null
Since:
1.5
See Also:
Comparable sample code for java.lang.Comparable definition code for java.lang.Comparable