java装饰模式。通过装饰完成对上层类的封装。

				import java.io.*;
				public class body extends abs
				{
					abs theAbs;
				
					public body(abs theAbs)
					{
						this.theAbs=theAbs;
					}
					/*print the body*/
					public void display()
					{
						theAbs.display();
						System.out.println("-----------------------------------------------\n");
						System.out.println("Item      Units        Unit Price      Subtotal\n");
					}
					public double getFinalCost()
					{
						return theAbs.getFinalCost();
					}
				}