JUint Test

Calculator.java

package junit.tutorial;

public class Calculator {

    public int multiply(int x, int y) {
        return x * y;
    }

    public float divide(int x, int y) {
        if (y == 0) {
            throw new IllegalArgumentException("divide by zero.");
        }

        return (float)x / (float)y;
    }
}

CalculatorTest.java

package junitt.tutorial;

import static org.junit.Assert.*;
import static org.hamcrest.CoreMatchers.*;
import junit.tutorial.Calculator;

import org.junit.Test;
import org.junit.Before;

public class CalculatorTest {

    private Calculator calculator = null;

    @Before
    public void setUp() throws Exception {
        // Set up
        this.calculator = new Calculator();
    }

    @Test
    public void multiplyTest3x4() {
        int expected = 12;

        // Exercise
        int actual = this.calculator.multiply(3, 4);

        // Verify
        assertThat(actual, is(expected));
    }

    @Test
    public void multiplyTest5x7() {
        int expected = 35;

        // Exercise
        int actual = this.calculator.multiply(5, 7);

        // Verify
        assertThat(actual, is(expected));
    }

    @Test
    public void divideTest3div2() {
        float expected = 1.5f;

        // Exercise
        float actual = calculator.divide(3, 2);

        // Verify
        assertThat(actual, is(expected));
    }

    @Test(expected = IllegalArgumentException.class)
    public void divideTest5div0() {
        // Exercise, Verify
        this.calculator.divide(5, 0);
    }

}