实验5-封装与测试2

测试类：

import junit.framework.TestCase;


public class CoreTest extends TestCase {

    protected void setUp() throws Exception {
        super.setUp();
    }

    public void testJisuan()throws yichang {
        Core core=new Core();
        int a=core.jisuan(4, 0, 2);
       assertEquals(0,a);
    }

}

计算类与异常类

public class Core {

int result=0;
public int  jisuan(int a,int b,int c)throws yichang{
    switch(c){
    case 1:
    {
    result=a+b;
    break;
    }
    case 2:
    {
        result=a-b;
        break;
    }
    case 3:
    {
        result=a*b;
        break;
    }
    case 4:
    {
        try{
            if(b==0){
                throw new yichang();
            }
        }catch(yichang e){
            e.dengyu();
        }
        result=a/b;
        break;
    }
    }
    return result;
}

}
class yichang extends Exception{
    public void dengyu(){
        System.out.println("分母不能为0");
    }
}