OnJava8-Examples/innerclasses/LocalInnerClass.java at master · xinan-w/OnJava8-Examples · GitHub

History

65 lines (63 loc) · 1.64 KB

Raw

// innerclasses/LocalInnerClass.java

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

// Holds a sequence of Objects

interface Counter {

int next();

}

public class LocalInnerClass {

private int count = 0;

Counter getCounter(final String name) {

// A local inner class:

class LocalCounter implements Counter {

LocalCounter() {

// Local inner class can have a constructor

System.out.println("LocalCounter()");

}

@Override public int next() {

System.out.print(name); // Access local final

return count++;

}

return new LocalCounter();

}

// Repeat, but with an anonymous inner class:

Counter getCounter2(final String name) {

return new Counter() {

// Anonymous inner class cannot have a named

// constructor, only an instance initializer:

{

System.out.println("Counter()");

}

@Override public int next() {

System.out.print(name); // Access local final

return count++;

}

};

}

public static void main(String[] args) {

LocalInnerClass lic = new LocalInnerClass();

Counter

c1 = lic.getCounter("Local inner "),

c2 = lic.getCounter2("Anonymous inner ");

for(int i = 0; i < 5; i++)

System.out.println(c1.next());

for(int i = 0; i < 5; i++)

System.out.println(c2.next());

}

/* Output:

LocalCounter()

Counter()

Local inner 0

Local inner 1

Local inner 2

Local inner 3

Local inner 4

Anonymous inner 5

Anonymous inner 6

Anonymous inner 7

Anonymous inner 8

Anonymous inner 9

OnJava8-Examples/innerclasses/LocalInnerClass.java at master · xinan-w/OnJava8-Examples · GitHub

Expand file tree

Breadcrumbs

LocalInnerClass.java

Latest commit

History

Breadcrumbs

LocalInnerClass.java

File metadata and controls