Myeclipse 使用JUnit 进行单元测试

Java计算器源码（只实现了加减乘除四种简单的运算）：

import java.math.BigDecimal;
import java.text.Format;
public class Caculator {
private BigDecimal num1;
private BigDecimal num2;
private String result;

public void setNum1(double num1) {
    this.num1 = new BigDecimal(num1);
}

public void setNum2(double num2) {
    this.num2 = new BigDecimal(num2);
}
private double _format(){
    BigDecimal _num1 = new BigDecimal(result);
    BigDecimal _num2 = new BigDecimal(1);
    return _num1.divide(_num2, 5,BigDecimal.ROUND_HALF_UP).doubleValue();    
}
public String getResult() {
    if(!result.equals("ERROR"))
    {
        double _res = _format();
        if(_res>=Double.MAX_VALUE||_res<=-Double.MAX_VALUE)
            result = "ERROR";
        else
            result = Double.toString(_format());        
    }        
    return result;
}
public void Add() {
    BigDecimal _result;
    _result = num1.add(num2);
    result = _result.toString();    
}
public void Sub() {
    BigDecimal _result;
    _result = num1.subtract(num2);
    result = _result.toString();    
}
public void Mul() {
    BigDecimal _result;
    _result = num1.multiply(num2);
    result = _result.toString();    
}
public void Div() {
    BigDecimal _result;
    if(num2.doubleValue()!=0){
        _result = num1.divide(num2);
        result = _result.toString();
    }
    else 
        result = "ERROR";
    }
    }

设计测试用例：

JUnit测试用例代码：

import org.junit.Test;
import java.math.BigDecimal;
import junit.framework.TestCase;
public class caculate_test extends TestCase {
    private Caculator ca = new Caculator();
    protected void setUp() throws Exception {
        super.setUp();
    }
    @Test
    public void test_Add() {
        ca.setNum1(1);
        ca.setNum2(2);
        ca.Add();
        assertEquals("3.0", ca.getResult());
        ca.setNum1(2.4);
        ca.setNum2(1.2);
        ca.Add();
        assertEquals("3.6", ca.getResult());
        ca.setNum1(Double.MAX_VALUE);
        ca.setNum2(2);
        ca.Add();
        assertEquals("ERROR", ca.getResult());
        }
    @Test
    public void test_Sub() {
        ca.setNum1(1);
        ca.setNum2(2);
        ca.Sub();
        assertEquals("-1.0", ca.getResult());
        ca.setNum1(2.4);
        ca.setNum2(1.2);
        ca.Sub();
        assertEquals("1.2", ca.getResult());
        ca.setNum1(-Double.MAX_VALUE);
        ca.setNum2(2);
        ca.Sub();
        assertEquals("ERROR", ca.getResult());
        }
    @Test
    public void test_Mul() {
        ca.setNum1(1);
        ca.setNum2(2);
        ca.Mul();
        assertEquals("2.0", ca.getResult());
        ca.setNum1(2.4);
        ca.setNum2(1.2);
        ca.Mul();
        assertEquals("2.88", ca.getResult());
        ca.setNum1(1.3);
        ca.setNum2(0);
        ca.Mul();
        assertEquals("0.0", ca.getResult());
        ca.setNum1(Double.MAX_VALUE);
        ca.setNum2(2);
        ca.Mul();
        assertEquals("ERROR", ca.getResult());
        }
    @Test
    public void test_Div() {
        ca.setNum1(1);
        ca.setNum2(2);
        ca.Div();
        assertEquals("0.5", ca.getResult());
        ca.setNum1(2.4);
        ca.setNum2(1.2);
        ca.Div();
        assertEquals("2.0", ca.getResult());
        ca.setNum1(1.3);
        ca.setNum2(0);
        ca.Div();
        assertEquals("ERROR", ca.getResult());
        }
}

测试结果：

GitHub:https://github.com/TongWee/SoftwareTesting_Caculator/