2013-09-16 100 views
-1

一切似乎都很完美,但测试用例仍然失败,给我一个所有这些的Java.lang.nullPointerException。为什么这个JUnit测试用例失败?

下面是测试案例

@Test 
    public void validMonths() { 
     DayOfWeek dow = new DayOfWeek(1, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("January") == 0); 
     dow = new DayOfWeek(2, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("February") == 0); 
     dow = new DayOfWeek(3, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("March") == 0); 
     dow = new DayOfWeek(4, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("April") == 0); 
     dow = new DayOfWeek(5, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("May") == 0); 
     dow = new DayOfWeek(6, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("June") == 0); 
     dow = new DayOfWeek(7, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("July") == 0); 
     dow = new DayOfWeek(8, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("August") == 0); 
     dow = new DayOfWeek(9, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("September") == 0); 
     dow = new DayOfWeek(10, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("October") == 0); 
     dow = new DayOfWeek(11, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("November") == 0); 
     dow = new DayOfWeek(12, 1, 1900); 
     assertTrue(dow.getMonthString().compareTo("December") == 0); 
    } 

这里是我的方法

public String getMonthString(){ 
     String[] arrayOfMonths = new String[11]; 
     arrayOfMonths[0] = "January"; 
     arrayOfMonths[1] = "February"; 
     arrayOfMonths[2] = "March"; 
     arrayOfMonths[3] = "April"; 
     arrayOfMonths[4] = "May"; 
     arrayOfMonths[5] = "June"; 
     arrayOfMonths[6] = "July"; 
     arrayOfMonths[7] = "August"; 
     arrayOfMonths[8] = "September"; 
     arrayOfMonths[9] = "October"; 
     arrayOfMonths[10] = "November"; 
     arrayOfMonths[11] = "December"; 
     if (this.myMonth > 0 && this.myMonth <=12){ 
      return arrayOfMonths[this.myMonth-1]; 
     } 
     else{ 
      return "NO_VALUE"; 
     } 
    } 

没有人知道是怎么回事?

+0

如果您发布堆栈跟踪并指出哪条线路正在抛出异常,这将会很有帮助。 –

+0

这行是失败跟踪,assertTrue(dow.getMonthString()。compareTo(“January”)== 0); –

+0

dow为null,dow.getMonthString()为null或compareTo()抛出NPE。打印出dow和get.getMonthString()。 –

回答

1

arrayOfMonths需要是大小为12,而不是11

编辑:谁upvoted我不应该有。 :-)这会抛出和ArrayIndexOutOfBoundsException,而不是NPE。这仍然是一个真正的问题,而不是他所拥有的。

+0

我改变后仍然失败 –