Individual Project

　　　　　　　　　　——JUnit 4 单元测试

　　学习到JUnit单元测试，我拿来测试之前写过的一个计算器（两个依存类：Calc.java CalcFunction.java）。代码已放到github中。

贴出部分代码：

 1 public class Calc extends javax.swing.JFrame{
 2 
 3         public Calc() {
 4             initComponents();
 5         }
 6 
 7         private void initComponents() {
 8             java.awt.GridBagConstraints gridBagConstraints;
 9 
10             setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
11             setTitle("\u8ba1\u7b97\u5668");
12             setBounds(new java.awt.Rectangle(500, 50, 0, 0));
13             setResizable(false);
14 
15                         ···//界面布局
16 
17                 }
18                 //主要监听
19         ActionListener listenerEquals = new ActionListener() {
20             public void actionPerformed(ActionEvent e) {
21                 formulaStand.setText(edit + "=");
22                 hasPoint = false;
23                 String result;
24                 try {
25                     result = CalcFunction.Evaluate(edit+"=");
26                 } catch (Exception e1) {
27                     result = "syntax error";
28                 }
29                 if (Double.parseDouble(result)%1 == 0) {
30                     editStand.setText(String.valueOf((int)Double.parseDouble((result))));
31                 }else{
32                     editStand.setText(String.valueOf((float)Double.parseDouble((result))));
33                 }
34                 edit = "0";
35             }
36         }; 
37 }

Calc.java

GUI布局类，运行的结果如下图：通过Botton输入表达式，传入CalcFunction类计算结果

这是计算器实现功能计算的类:

  1 package com.school.indivodial;
  2 
  3 import java.util.EmptyStackException;
  4 import java.util.Stack;
  5 
  6 public class CalcFunction {
  7     private static String[] TrnsInToSufix(String IFX) { // PFX放后缀表达式，IFX为中缀表达式
  8         String PFX[] = new String[IFX.length()];
  9         StringBuffer numBuffer = new StringBuffer();// 用来保存一个数的
 10         Stack<String> s = new Stack<String>();// 放操作符
 11         String a;
 12         s.push("=");// 第一个为等号
 13         int i = 0, j = 0;
 14         char ch;
 15 
 16         ··· // 栈操作，中缀表达式转后缀表达式
 17 
 18         return PFX;
 19     }
 20 
 21     public static String Evaluate(String IFX) throws Exception {// 后缀表达式求值
 22 
 23         String PFX[] = null;
 24         try {
 25             PFX = TrnsInToSufix(IFX);
 26         } catch (EmptyStackException e) {
 27             return "syntax error";
 28         }
 29         int i = 0;
 30         double x1, x2, n;
 31         String str;
 32         Stack<String> s = new Stack<String>();
 33         while (PFX[i] != "=") {
 34             str = PFX[i];
 35             switch (str.charAt(0)) {
 36             case '0':
 37             case '1':
 38             case '2':
 39             case '3':
 40             case '4':
 41             case '5':
 42             case '6':
 43             case '7':
 44             case '8':
 45             case '9':
 46                 s.push(str);
 47                 break;
 48             case '+':
 49                 x1 = Double.parseDouble(s.pop());
 50                 x2 = Double.parseDouble(s.pop());
 51                 n = x1 + x2;
 52                 s.push(String.valueOf(n));
 53                 break;
 54             case '-':
 55                 x1 = Double.parseDouble(s.pop());
 56                 x2 = Double.parseDouble(s.pop());
 57                 n = x2 - x1;
 58                 s.push(String.valueOf(n));
 59                 break;
 60             case '×':
 61                 x1 = Double.parseDouble(s.pop());
 62                 x2 = Double.parseDouble(s.pop());
 63                 n = x1 * x2;
 64                 s.push(String.valueOf(n));
 65                 break;
 66             case '÷':
 67                 x1 = Double.parseDouble(s.pop());
 68                 x2 = Double.parseDouble(s.pop());
 69                 n = x2 / x1;
 70                 s.push(String.valueOf(n));
 71                 break;
 72             case 'o':
 73                 x1 = Double.parseDouble(s.pop());
 74                 n = Math.log10(x1);
 75                 s.push(String.valueOf(n));
 76                 break;
 77             case 'n':
 78                 x1 = Double.parseDouble(s.pop());
 79                 n = Math.log1p(x1);
 80                 s.push(String.valueOf(n));
 81                 break;
 82             case '\u221a'://'√'
 83                 x1 = Double.parseDouble(s.pop());
 84                 n = Math.sqrt(x1);
 85                 s.push(String.valueOf(n));
 86                 break;// 开方
 87             case '^':
 88                 x1 = Double.parseDouble(s.pop());
 89                 x2 = Double.parseDouble(s.pop());
 90                 n = Math.pow(x2, x1);
 91                 s.push(String.valueOf(n));
 92                 break;
 93             ···//其他运算
 94     
 95             }
 96             i++;
 97         }
 98         String result = s.pop();
 99         return result;
100     }
101 
102 }

CalcFunction.java

　　下面进行单元测试：测试CalcFunction类的方法计算结果是否有错误。

首先要在该工程下导入JUnit库具体做法：Build Path -> Config Build Path ... -> Add Libraries ... 选中JUnit Next-> 选择JUnit 4 Finished

添加完成

创建测试用例

new -> Java Test Case Name：CalcFunctionTest Next-> 选择要测试的方法 ->finished

自动生成一个测试类CalcFunctionTest，里面包含一些空的测试用例，@Test 注解的。只需要将这些测试用例稍作修改即可使用。完整的CalcFunctionTest代码如下：

 1 package com.school.indivodial;
 2 
 3 import static org.junit.Assert.assertEquals;
 4 
 5 import org.junit.Test;
 6 
 7 /**
 8  * 
 9  * @author lendoon
10  *CalcFunction类是Calc类的功能类，
11  *Calc的UI输入中缀表达式调用CalcFunction的静态Evaluate方法计算返回结果
12  */
13 public class CalcFunctionTest {
14     
15     @Test
16     public void testEvaluate_basic() throws Exception {
17         Double expectedAnswer = Double.valueOf("90");
18         Double actualAnswer = Double.valueOf(CalcFunction.Evaluate("100-(22+6×3)÷4="));
19         assertEquals(expectedAnswer, actualAnswer);
20     }
21 
22     @Test
23     public void testEvaluate_pow() throws Exception{
24         Double expectedAnswer = Double.valueOf("1024");
25         Double actualAnswer = Double.valueOf(CalcFunction.Evaluate("2^10="));
26         assertEquals(expectedAnswer, actualAnswer);
27     }
28     
29     @Test
30     public void testEvaluate_sqrt() throws Exception{
31         Double expectedAnswer = Double.valueOf("8");
32         Double actualAnswer = Double.valueOf(CalcFunction.Evaluate("√64="));
33         assertEquals(expectedAnswer, actualAnswer);
34     }
35     
36     @Test
37     public void testEvaluate_cos() throws Exception{
38         Double expectedAnswer = Double.valueOf("1");
39         Double actualAnswer = Double.valueOf(CalcFunction.Evaluate("COS(0)="));
40         assertEquals(expectedAnswer, actualAnswer);
41     }
42 }