this

public class TestThis {
	public static void main(String[] args) {
		Child c = new Child();
		c.info();
	}
}

class Parent {
	public void info() {
		System.out.println("info:" + this.toString());
	}
}

class Child extends Parent {
	public Child() {
		System.out.println("construct:" + this.toString());
	}
}

结果：

construct: Child@2260e277
info:         Child@2260e277

https://my.oschina.net/mlongbo/blog/90047　　

package com.if1;

class Parent {
	public void print() {
		System.out.println("Parent.");
	}

	public void info() {
		print(); // == this.print();
	}
}

class Child extends Parent {
	public void print() {
		System.out.println("Child.");
	}
}

public class TestThis {
	public static void main(String[] args) {
		Child c = new Child();
		c.info();
	}
}

结果：Child.

《java编程思想》：编译器会“偷偷的”将this关键字传入进去，所以在设计继承时，要特别注意。

“this关键字只能在方法内部使用，表示对调用方法的那个对象的引用”

http://blog.csdn.net/u012585142/article/details/50918190