Boolean (Java Platform SE 7 ) (original) (raw)

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 typeboolean in an object. An object of typeBoolean contains a single field whose type isboolean.
In addition, this class provides many methods for converting a boolean to a String and aString to a boolean, as well as other constants and methods useful when dealing with aboolean.
Since:
JDK1.0
See Also:
Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static Boolean	FALSE The Boolean object corresponding to the primitive value false.
static Boolean	TRUE The Boolean object corresponding to the primitive value true.
static Class<Boolean>	TYPE The Class object representing the primitive type boolean.

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and 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.
boolean	equals(Object obj) Returns true if and only if the argument is notnull 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.
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 specifiedboolean value.
static Boolean	valueOf(String s) Returns a Boolean with a value represented by the specified string.

   * ### Methods inherited from class java.lang.[Object](../../java/lang/Object.html "class in java.lang")  
   `[clone](../../java/lang/Object.html#clone%28%29), [finalize](../../java/lang/Object.html#finalize%28%29), [getClass](../../java/lang/Object.html#getClass%28%29), [notify](../../java/lang/Object.html#notify%28%29), [notifyAll](../../java/lang/Object.html#notifyAll%28%29), [wait](../../java/lang/Object.html#wait%28%29), [wait](../../java/lang/Object.html#wait%28long%29), [wait](../../java/lang/Object.html#wait%28long,%20int%29)`

Field Detail

 * #### TRUE  
 public static final [Boolean](../../java/lang/Boolean.html "class in java.lang") TRUE  
 The `Boolean` object corresponding to the primitive value `true`.  
 * #### FALSE  
 public static final [Boolean](../../java/lang/Boolean.html "class in java.lang") FALSE  
 The `Boolean` object corresponding to the primitive value `false`.  
 * #### TYPE  
 public static final [Class](../../java/lang/Class.html "class in java.lang")<[Boolean](../../java/lang/Boolean.html "class in java.lang")> TYPE  
 The Class object representing the primitive type boolean.  
 Since:  
 JDK1.1

Constructor Detail

* #### 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)](../../java/lang/Boolean.html#valueOf%28boolean%29) is generally a better choice. It is likely to yield significantly better space and time performance.**  
Parameters:  
`value` \- the value of the `Boolean`.  
* #### Boolean  
public Boolean([String](../../java/lang/String.html "class in java.lang") 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  
public static boolean parseBoolean([String](../../java/lang/String.html "class in java.lang") 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  
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](../../java/lang/Boolean.html "class in java.lang") 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)](../../java/lang/Boolean.html#Boolean%28boolean%29), 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](../../java/lang/Boolean.html "class in java.lang") valueOf([String](../../java/lang/String.html "class in java.lang") 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.  
* #### toString  
public static [String](../../java/lang/String.html "class in java.lang") 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](../../java/lang/String.html "class in java.lang") 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](../../java/lang/Object.html#toString%28%29)` in class `[Object](../../java/lang/Object.html "class in java.lang")`  
Returns:  
a string representation of this object.  
* #### hashCode  
public int hashCode()  
Returns a hash code for this `Boolean` object.  
**Overrides:**  
`[hashCode](../../java/lang/Object.html#hashCode%28%29)` in class `[Object](../../java/lang/Object.html "class in java.lang")`  
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)](../../java/lang/Object.html#equals%28java.lang.Object%29), [System.identityHashCode(java.lang.Object)](../../java/lang/System.html#identityHashCode%28java.lang.Object%29)  
* #### equals  
public boolean equals([Object](../../java/lang/Object.html "class in java.lang") 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](../../java/lang/Object.html#equals%28java.lang.Object%29)` in class `[Object](../../java/lang/Object.html "class in java.lang")`  
Parameters:  
`obj` \- the object to compare with.  
Returns:  
`true` if the Boolean objects represent the same value; `false` otherwise.  
See Also:  
[Object.hashCode()](../../java/lang/Object.html#hashCode%28%29), [HashMap](../../java/util/HashMap.html "class in java.util")  
* #### getBoolean  
public static boolean getBoolean([String](../../java/lang/String.html "class in java.lang") 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)](../../java/lang/System.html#getProperty%28java.lang.String%29), [System.getProperty(java.lang.String, java.lang.String)](../../java/lang/System.html#getProperty%28java.lang.String,%20java.lang.String%29)  
* #### compareTo  
public int compareTo([Boolean](../../java/lang/Boolean.html "class in java.lang") b)  
Compares this `Boolean` instance with another.  
**Specified by:**  
`[compareTo](../../java/lang/Comparable.html#compareTo%28T%29)` in interface `[Comparable](../../java/lang/Comparable.html "interface in java.lang")<[Boolean](../../java/lang/Boolean.html "class in java.lang")>`  
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](../../java/lang/NullPointerException.html "class in java.lang")` \- if the argument is `null`  
Since:  
1.5  
See Also:  
[Comparable](../../java/lang/Comparable.html "interface in java.lang")  
* #### 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

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Boolean (Java Platform SE 7 ) (original) (raw)

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail