[options] 未与 -source 1.6 一起设置引导类路径

[梦里香格里拉]

生成帮助文档时出现警告：“[options] 未与 -source 1.6 一起设置引导类路径”
是什么原因，怎么解决


源代码如下：
package com.usydapeng;

/**
*
* @author usydapeng
*
*/
public class Point {
private int x;
private int y;

/**
*
* @param x coordinate of x
* @param y coordinate of y
*/
public Point(int x, int y) {
this.x = x;
this.y = y;
}

/**
* @return return coordinate of axis of x and y;
*/
@Override
public String toString() {
return "[ x = " + x + ", y =" + y + "]";
}
}

-----------------------------
package com.usydapeng;

import java.util.ArrayList;
/**
*
* @author usydapeng
*
*/
public class ArrayListTest {
public static void main(String[] arg) {
ArrayList<Point> list;
list = new ArrayList<Point>();

list.add(new Point(2, 5));
list.add(new Point(3, 7));
list.add(new Point(1, 9));

System.out.println(list);
}
}