Java language defines a public, protected, private, abstract, static and final modifiers commonly used outside the 6 also defines five less commonly used modifiers, the following are Java modifiers of this 11 presentation:
1.public
Use the object: class, interface, members of the
Description: Whether it is in the package are defined in which, the class (interface, members) are accessible
2.private
Using Object: Members
Description: Members of the definition can only be accessed in its class
3.static
Use the object: class, method, field, initialization function
Description: famous for the static inner class is a top class, it includes members of the class is not relevant. Static method class method, are pointing to their class rather than class. Static field is the class field, no matter where the class of the field to create a number of instances, there is only one instance of the field is pointing to their class rather than class. Initialization function is executed in the loaded class, rather than creating an instance of time-consuming.
4.final
Use the object: class, method, field, variable
Description: The definition of the class is not allowed into the final sub-category, can not be covered (not used in dynamic query), field values are not allowed to be modified.
5.abstract
Use the object: class, interface, methods
Description: Class includes methods not implemented, can not be instantiated. If it is a abstract way, the method body is empty, the method of implementation is defined in subclasses, and includes an abstract method of abstract class type must be a
6.protected
Using Object: Members
Description: Members of the definition it can only be accessed package, if the other package is accessed, the class must implement this method is that the members of their class, subclass.
7.native
Using Object: Members
Description: associated with the operating platform, the definition does not define the method, method of implementation is an external library implementation.
8.strictfp
Use the object: class, method
Description: strictfp modified class hides all of the methods strictfp modifiers, methods, implementation of all the floating-point calculations to comply with IEEE754 standard, all values including intermediate results can be expressed as the float or double type, unable to take advantage from the local platform floating-point format or hardware to provide the additional accuracy or that the scope.
9.synchronized
Using Object: Methods
Description: For a static method, before the implementation of the jvm to lock it in the class; for a non-static class methods, the implementation of a particular object instance before the lock.
10.volatile
Use the object: the field
Description: Because asynchronous thread can access the field, so there is certainly no role in optimizing operation on the field. volatile can sometimes substitute synchronized.
11.transient
Use the object: the field
Description: field is not part of persistent state objects, fields and objects should not be strung together.
No comments:
Post a Comment