Class java.lang.Boolean - JDK 5 Documentation v1.1.8, Java 2 SDK 英文文档

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Class java.lang.Boolean

java.lang.Object
   |
   +----java.lang.Boolean

public final class Boolean
extends Object
implements Serializable

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.

FALSE: The Boolean object corresponding to the primitive value false.
TRUE: The Boolean object corresponding to the primitive value true.
TYPE: The Class object representing the primitive type boolean.

Boolean(boolean): Allocates a Boolean object representing the value argument.
Boolean(String): Allocates a Boolean object representing the value true if the string argument is not null and is equal, ignoring case, to the string "true".

booleanValue(): Returns the value of this Boolean object as a boolean.
equals(Object): Returns true if and only if the argument is not null and is a Boolean object that contains the same boolean value as this object.
getBoolean(String): Returns is true if and only if the system property named by the argument exists and is equal to the string "true".
hashCode(): Returns a hash code for this Boolean.
toString(): Returns a String object representing this Boolean's value.
valueOf(String): Returns the boolean value represented by the specified String.

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 TYPE

The Class object representing the primitive type boolean.

Boolean

 public Boolean(boolean value)

Allocates a Boolean object representing the value argument.

Parameters:: value - the value of the Boolean.

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.

Parameters:: s - the string to be converted to a Boolean.

booleanValue

 public boolean booleanValue()

Returns the value of this Boolean object as a boolean.

Returns:: the primitive boolean value of this object.

valueOf

 public static Boolean valueOf(String s)

Returns the boolean value represented by the specified String. A new Boolean object is constructed. This Boolean contains the value true 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.

toString

 public String toString()

Returns a String object representing this Boolean's value. If this object contains 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.
Overrides:: toString in class Object

hashCode

 public int hashCode()

Returns a hash code for this Boolean.

Returns:: a hash code value for this object.
Overrides:: hashCode in class Object

equals

 public boolean equals(Object obj)

Returns true if and only if the argument is not null and is a Boolean object that contains the same boolean value as this object.

Parameters:: obj - the object to compare with.
Returns:: true if the objects are the same; false otherwise.
Overrides:: equals in class Object

getBoolean

 public static boolean getBoolean(String name)

Returns is true if and only if the system property named by the argument exists and is equal to the string "true". (Beginning with Java 1.0.2, the test of this string is case insensitive.) A system property is accessible through getProperty, a method defined by the System class.

Parameters:: name - the system property name.
Returns:: the boolean value of the system property.
See Also:: getProperty, getProperty

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