The composition of the interface update

1.1 updated overview of the composition of the interface
consisting of interface
● Constant
　　public static Final
● abstract methods
　　public abstract
● default method (the Java 8)
● static method (the Java 8)
● private method (Java9)

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1.2 Interface default method
Interface method defined default format:
● Format: public default return type method name (parameter list) {}

Example: public default void show3 () {}

The default interface method Notes:
● The default method is not abstract method, it is not mandatory to be rewritten. But can be rewritten, rewritten when removing the default keyword
● public can be omitted, default can not be omitted

public interface MyInterface {
    void show1();

    void show2();

    //    void show3();
    public default void show3() {
        System.out.println("show3");
    }
}

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1.3 Interface static methods
defined format interface static methods:
　　● Format: public static return type method name (parameter list) {}
　　● Example: public static void show () { }
interfaces static methods Note:
　　● Static The method calls only through the interface name, class name can not be achieved by object name or call
　　● public may be omitted, static can not be omitted

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1.4 interface private methods
Java 9 added a private body with methods, which is actually in Java 8 foreshadowed: The default method is defined with a method body interface in Java 8 permit
and static methods. This might lead to eleven question: When two default methods or static methods contained in the same section of code implementation, the program is bound to consider
the realization of this code is drawn into a common method, but this method does not require the common people used, hence the private to hide, this is the Java 9
increases Necessity private process
definitions format private methods Interface:
　　　　format 1: private return type method name (parameter list) {}
　　　　　　● example 1: private void show ( )} {

　　　　● Format 2: private static method return type name (parameter list) {}
　　　　　　● Example 2: private static void method ({ }

Notes interface private methods:
● default method can call private static methods and non-static methods
● static method can only be called private static method

 

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