mainclass.java

大学java作业源程序

package problem_11_1;
//MainClass.java
import java.io.*;

public class MainClass {
	public static void main(String[] args){
		try{
			//输出提示输入信息
			System.out.println("Selection pool: apple/pear/apple+pear");
			System.out.print("Please choose the variety of fruit mixed in the juice: ");
			BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
			String choice = new String(br.readLine());		//读入水果选项
			System.out.print("Provisional standard sugar rate = ");
			Double stdSugarRate = Double.valueOf(br.readLine());		//读入标准含糖率
			System.out.print("Provisional standard vitamin rate = ");
			Double stdVitaminRate = Double.valueOf(br.readLine());		//读入标准含维生素率
			System.out.print("Juice weight = ");
			Double juiceWeight = Double.valueOf(br.readLine());		//读入果汁总重量
			boolean isSelectionValid = true;
			Juice juice;
			if (choice.equals("apple"))		//选择苹果
				juice = new Juice(juiceWeight, newApple());
			else if(choice.equals("pear"))	//选择梨
				juice = new Juice(juiceWeight, newPear());
			else if(choice.equals("apple+pear"))		//选择苹果和梨
				juice = new Juice(juiceWeight, newApple(), newPear());
			else{		//其他输入，无效
				System.out.println("Invalid selection");
				juice = new Juice(0);
				isSelectionValid = false;
			}
			if(isSelectionValid){		//选择有效
				System.out.println("\nAbout the juice:");
				System.out.println("Total jucie amount = " + juice.getTotalWeight());
				System.out.println("Contained pure water = " + juice.getWaterAmount());
				System.out.println("Contained sugar = " + juice.getSugarAmount());
				System.out.println("Contained vitamin =" + juice.getVitaminAmount());
				System.out.println("Sugar rate = " + juice.getSugarRate());
				System.out.println("Vitamin rate = " + juice.getVitaminRate());
				if(stdSugarRate.compareTo(juice.getSugarRate()) <= 0)		//果汁含糖率符合标准
					System.out.println("Sugar rate is qualified");
				else		//果汁含糖率不符合标准
					System.out.println("Sugar rate is not qualified");
				if(stdVitaminRate.compareTo(juice.getVitaminRate()) <= 0)		//果汁含维生素量符合标准
					System.out.println("Vitamin rate is qualified");
				else		//果汁含维生素率不符合标准
					System.out.println("Vitamin rate is not qualified");
			}
		}
		catch(IOException e){
			System.out.println(e);
		}
	}
	
	//构造Apple类对象并返回
	private static Apple newApple() throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		System.out.print("Apple weight = ");
		return new Apple(Double.valueOf(br.readLine()));
	}
	
	//构造Pear类对象并返回
	private static Pear newPear() throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		System.out.print("Pear weight = ");
		return new Pear(Double.valueOf(br.readLine()));
	}
}