内部类的实现方式有很多种,其中内明内部类和局部内部类比较常见,下面的一个例子主要是针对这两种实现方式做一个简单的比较
package com.eric.interfaceAndInnerClass;
interface Counter {
public void add();
}
/**
* 这个类主要说明通过匿名内部类和局部内部类的方式来实现内部类,以及说明了内部类可以不受限制的访问外围类的成员
* 局部内部类可以有构造方法,可是匿名内部类只能通过初始化域类进行初始化
* @author Eric
*
*/
public class LocalInnerClass2 {
private int count = 0;
public Counter getCounter(String counterName) {
class Counter1 implements Counter {
public void add() {
count++;
System.out.println("count in Counter1:" + count);
}
public Counter1(String counterName) {
System.out.println("output by:" + counterName);
}
class Count1Inner{
}
}
return new Counter1(counterName);
}
public Counter getCounter2(final String CounterName) {
return new Counter() {
{
System.out.println("output by:" + CounterName);
}
public void add() {
count++;
System.out.println("count in Count2:" + count);
}
};
}
public static void main(String[] args) {
LocalInnerClass2 lc = new LocalInnerClass2();
Counter c1 = lc.getCounter("COUNTER1");
Counter c2 = lc.getCounter2("COUNTER2");
for (int i = 0; i < 5; i++) {
c1.add();
c2.add();
}
}
}