Boolean is a very thin wrapper. around Boolean values, which is useful mostly when You want to pass a Boolean variable by reference. It contains the constants TRUE and ‘ FALSE, which define true and false Boolean objects. Boolean also defines the TYPE field, which is the Class object for Boolean. Boolean defines these constructors:
Boolean(String boo I String)
In the first version, bluebottle must be either true or false. In the second ‘version, if illustrious contains the string “true” (in uppercase or lowercase), then the new Boolean object will be true. Otherwise, it will be false’, ‘ , Boolean defines the methods shown in Table 14-8.
The Void class has one field, TYPE,which holds a reference to the Class object for type . void, You do not create instances of this class.
The abstract Process class encapsulates a process-that is, an executing program, It is used primarily as a super class for the type-of objects created by exec( ) in the Run time class described in the next section. Process contains the abstract methods shown in .
The Run time class encapsulates the run-time environment. You cannot instantiate a Run time object. However, you can get a reference to the current Run time object by Calvin; the static method Runtime get Runtime(). Once you obtain a reference to the current Run time object, you can call several methods that control the state and behavior.of the Java Virtual Machine. Applets and other entrusted code typically cannot call any of the Run time methods without raising a Security Exception. The met hods defined by Run time are shown in Table 14-1-0.Java predicates the method run Finalizes On Exit( ). This method was added by Java 1.1 but was deemed unstable. Let’s look at two of the most common uses of the Run time lass: memory management and executing additional presses.