Class Boolean
- java.lang.Object
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- java.lang.Boolean
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- 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 typebooleanin an object. An object of typeBooleancontains a single field whose type isboolean.In addition, this class provides many methods for converting a
booleanto aStringand aStringto aboolean, as well as other constants and methods useful when dealing with aboolean.- See Also:
- Serialized Form
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Constructor Summary
Constructors Constructor Description Boolean(boolean value)Allocates aBooleanobject representing thevalueargument.Boolean(String s)Allocates aBooleanobject representing the valuetrueif the string argument is notnulland is equal, ignoring case, to the string"true".
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description booleanbooleanValue()Returns the value of thisBooleanobject as a boolean primitive.static intcompare(boolean x, boolean y)Compares twobooleanvalues.intcompareTo(Boolean b)Compares thisBooleaninstance with another.booleanequals(Object obj)Returnstrueif and only if the argument is notnulland is aBooleanobject that represents the samebooleanvalue as this object.static booleangetBoolean(String name)Returnstrueif and only if the system property named by the argument exists and is equal to the string"true".inthashCode()Returns a hash code for thisBooleanobject.static booleanparseBoolean(String s)Parses the string argument as a boolean.StringtoString()Returns aStringobject representing this Boolean's value.static StringtoString(boolean b)Returns aStringobject representing the specified boolean.static BooleanvalueOf(boolean b)Returns aBooleaninstance representing the specifiedbooleanvalue.static BooleanvalueOf(String s)Returns aBooleanwith a value represented by the specified string.
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Constructor Detail
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Boolean
public Boolean(boolean value)
Allocates aBooleanobject representing thevalueargument.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 theBoolean.
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Boolean
public Boolean(@Nullable String s)
Allocates aBooleanobject representing the valuetrueif the string argument is notnulland is equal, ignoring case, to the string"true". Otherwise, allocate aBooleanobject representing the valuefalse. Examples:new Boolean("True")produces aBooleanobject that representstrue.
new Boolean("yes")produces aBooleanobject that representsfalse.- Parameters:
s- the string to be converted to aBoolean.
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Method Detail
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compare
public static int compare(boolean x, boolean y)Compares twobooleanvalues. The value returned is identical to what would be returned by:Boolean.valueOf(x).compareTo(Boolean.valueOf(y))
- Parameters:
x- the firstbooleanto comparey- the secondbooleanto compare- Returns:
- the value
0ifx == y; a value less than0if!x && y; and a value greater than0ifx && !y
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getBoolean
public static boolean getBoolean(String name)
Returnstrueif 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 throughgetProperty, a method defined by theSystemclass.If there is no property with the specified name, or if the specified name is empty or null, then
falseis returned.- Parameters:
name- the system property name.- Returns:
- the
booleanvalue of the system property. - See Also:
System.getProperty(java.lang.String),System.getProperty(java.lang.String, java.lang.String)
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parseBoolean
public static boolean parseBoolean(@Nullable String s)
Parses the string argument as a boolean. Thebooleanreturned represents the valuetrueif the string argument is notnulland is equal, ignoring case, to the string"true".Example:
Boolean.parseBoolean("True")returnstrue.
Example:Boolean.parseBoolean("yes")returnsfalse.- Parameters:
s- theStringcontaining the boolean representation to be parsed- Returns:
- the boolean represented by the string argument
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toString
public static String toString(boolean b)
Returns aStringobject representing the specified boolean. If the specified boolean istrue, 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
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valueOf
public static Boolean valueOf(boolean b)
Returns aBooleaninstance representing the specifiedbooleanvalue. If the specifiedbooleanvalue istrue, this method returnsBoolean.TRUE; if it isfalse, this method returnsBoolean.FALSE. If a newBooleaninstance is not required, this method should generally be used in preference to the constructorBoolean(boolean), as this method is likely to yield significantly better space and time performance.- Parameters:
b- a boolean value.- Returns:
- a
Booleaninstance representingb.
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valueOf
public static Boolean valueOf(@Nullable String s)
Returns aBooleanwith a value represented by the specified string. TheBooleanreturned represents a true value if the string argument is notnulland is equal, ignoring case, to the string"true".- Parameters:
s- a string.- Returns:
- the
Booleanvalue represented by the string.
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booleanValue
public boolean booleanValue()
Returns the value of thisBooleanobject as a boolean primitive.- Returns:
- the primitive
booleanvalue of this object.
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compareTo
public int compareTo(Boolean b)
Compares thisBooleaninstance with another.- Specified by:
compareToin interfaceComparable<Boolean>- Parameters:
b- theBooleaninstance 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 isnull- See Also:
Comparable
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equals
public boolean equals(@Nullable Object obj)
Returnstrueif and only if the argument is notnulland is aBooleanobject that represents the samebooleanvalue as this object.- Overrides:
equalsin classObject- Parameters:
obj- the object to compare with.- Returns:
trueif the Boolean objects represent the same value;falseotherwise.- See Also:
Object.hashCode(),HashMap
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hashCode
public int hashCode()
Returns a hash code for thisBooleanobject.- Overrides:
hashCodein classObject- Returns:
- the integer
1231if this object representstrue; returns the integer1237if this object representsfalse. - See Also:
Object.equals(java.lang.Object),System.identityHashCode(java.lang.Object)
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toString
public String toString()
Returns aStringobject representing this Boolean's value. If this object represents the valuetrue, a string equal to"true"is returned. Otherwise, a string equal to"false"is returned.
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