两种测试异常处理

第一种 

@Test(expected = IllegalArgumentException.class)

第二种

@Rule

被测试的类

public class FizzBuzz {
    /**
     * Write a progarm that prints the numbers from 1 to 100.
     * Multiples of Three print "Fizz" instead of the number.
     * Multiples of Five print "Buzz" instead of the number.
     * Multiples of Three To Five print "Buzz" instead of the number.
     */

    //constant
    public static String Three_Multiples = "Fizz";
    public static String Five_Multiples = "Buzz";
    public static String Three_And_Five_Multiples = "FizzBuzz";
    public static String No_1_TO_100 = "Invalid data";

    public static String getAnswerFor(int number){
        isOvernumber(number);
        return Judge_Three_And_Five_Multiples(number);
    }

    private static void isOvernumber(int number){
        if (Judge_No_1_To_100(number)){
            throw new IllegalArgumentException(No_1_TO_100);
        }
    }


    public static String Judge_Three_And_Five_Multiples(int number) {
        if (Judge_Three_To_Five_Multiples(number)) {
            return Three_And_Five_Multiples;
        }
        if (Judge_Three_Multiples(number)) {
            return Three_Multiples;
        }
        if (Judge_Five_Multiples(number)) {
            return Five_Multiples;
        }
        return String.valueOf(number);
    }

    //check if it is a multiple of three
    private static boolean Judge_Three_Multiples(int number) {
        return number % 3 == 0;
    }

    //check if it is a multiple of five
    private static boolean Judge_Five_Multiples(int number) {
        return number % 5 == 0;
    }

    //check if it is a multiple of three and five
    private static boolean Judge_Three_To_Five_Multiples(int number) {
        return Judge_Three_Multiples(number) && Judge_Five_Multiples(number);
    }

    //check if it is the numbers from 1 to 100

    private static boolean Judge_No_1_To_100(int number) {
        return number > 100 || number < 1;
    }
}

@Test(expected = IllegalArgumentException.class) 

import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

public class FizzBuzzTest {
    private Integer Test_Small_1_Number = -1;
    private Integer Test_1_Number = 1;
    private Integer Test_2_Number = 2;
    private Integer Test_3_Number = 3;
    private Integer Test_5_Number = 5;
    private Integer Test_15_Number = 15;
    private Integer Test_101_Number = 101;

    /**
     * 测试大于100的数字 101
     * 断言期望值与实际值是否相等
     */
    @Test(expected = IllegalArgumentException.class)
    public void FizzBuzz_Big_100() {
        //assert that the number is 101 and whether the expected value "Invalid data" is reached
       FizzBuzz.getAnswerFor(Test_Small_1_Number);
          }

FizzBuzz.getAnswerFor():测试的信息

由于是静态方法,所以直接 类名.方法名 调用 FizzBuzz中写好的getAnswerFor方法

 由于是静态方法,所以直接 类名.方法名 调用 FizzBuzz中写好的getAnswerFor方法

@Rule

import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

public class FizzBuzzTest {
    private Integer Test_Small_1_Number = -1;
    private Integer Test_1_Number = 1;
    private Integer Test_2_Number = 2;
    private Integer Test_3_Number = 3;
    private Integer Test_5_Number = 5;
    private Integer Test_15_Number = 15;
    private Integer Test_101_Number = 101;


    @Rule
    public ExpectedException thrown = ExpectedException.none();
    /**
     * 测试循环小于于1的数字 -1
     * 断言期望值：Invalid data与实际值是否相等
     */
    @Test
    public void FizzBuzz_Small_1() {
        //assert that the number is -1 and whether the expected value "Invalid data" is reached
        thrown.expect(IllegalArgumentException.class);
        thrown.expectMessage(FizzBuzz.No_1_TO_100);
        FizzBuzz.getAnswerFor(Test_Small_1_Number);
    }

expect():表明测试会抛出一个异常

expectMessage():抛出异常信息

FizzBuzz.getAnswerFor():测试的信息

由于是静态方法,所以直接 类名.方法名 调用 FizzBuzz中写好的getAnswerFor方法