Java 中switch语句，case四个，但是不管选择1234的哪个，都是按照第一个输出

Question

/*
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 * and open the template in the editor.
 */
package hz;
import java.io.*;
/**
 *
 * @author user
 */
public class Hz {
    public static void main(String[] args){
    try
    {
                InputStreamReader isr = new  InputStreamReader (System.in);
                BufferedReader br = new BufferedReader(isr);
                System.out.println("请输入计算种类：\n1.四则运算：\n2.计算面积：");
                int i1 = Integer.valueOf(br.readLine());
                if(i1==1)
                {
                    System.out.println("输入计算方法:\n1.加法\n2.减法\n3.乘法\n4.除法");
                    int i2 = Integer.valueOf(br.readLine());
                    System.out.println("输入两个数用空格隔开：");
                    String[] s = br.readLine().split(" ");
                    double x = Double.valueOf(s[0]);
                    double y = Double.valueOf(s[1]); 
                    switch(i1)
                    {
                        case 1:
                                System.out.println(x+"+"+y+"="+(x+y));
                                break;
                                
                        case 2:
                                System.out.println(x+"-"+y+"="+(x-y));
                                break;
                        case 3:
                                System.out.println(x+"*"+y+"="+(x*y));
                                break;
                        case 4:
                                System.out.println(x+"/"+y+"="+(x/y));
                                break;
                    }   
                }else
                {
                    System.out.println("选择图形：\n1.正方形\n2.矩形\n3.图形\n4.三角形");
                    int i2 = Integer.valueOf(br.readLine());
                    System.out.println("输入两个数用空格隔开：");
                    String[] s = br.readLine().split(" ");
                    double x = Double.valueOf(s[0]);
                    
                    switch(i2)
                    {
                        case 1:
                                System.out.println("正方形面积："+x*x);
                                break;
                        case 2:
                                double y = Double.valueOf(s[1]);
                                System.out.println("矩形面积："+x*y);
                                break;
                        case 3:
                                System.out.println("圆形面积："+Math.PI*x*x);
                                break;
                        case 4:
                                 double z = Double.valueOf(s[1]);
                                System.out.println("三角形面积："+0.5*x*z);
                                break;
                }
    }
    }catch(Exception e)
    {
        e.printStackTrace();
        
    }}

     
    
    
    
    
    
    
    
    
}

Answer 1

应该使用i2作为switch的条件,i1是第一个选择,i2才是第二个选择