Holds a sequence of Objects : Inner Class « Class « Java
Holds a sequence of Objects
// : c08:LocalInnerClass.java
// Holds a sequence of Objects.
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
interface Counter {
int next();
}
public class LocalInnerClass {
private int count = 0;
Counter getCounter(final String name) {
// A local inner class:
class LocalCounter implements Counter {
public LocalCounter() {
// Local inner class can have a constructor
System.out.println("LocalCounter()");
}
public int next() {
System.out.print(name); // Access local final
return count++;
}
}
return new LocalCounter();
}
// The same thing 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()");
}
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());
}
} ///:~
