Java单元测试进阶之如何打桩（扫除打桩的最后一道坎－使用easymockclassextension打桩类）

用easymockclassextension进行类的打桩跟用easymock进行接口的打桩的步骤差不多，能执行的操作也差不多，看看下面代码：
欲打桩类：


/************************************************************


* 项目名称:lhjTest


* 文件名称:CoolClass.java


* 文件描述:CoolClass.java


* 作者:Administrator


* 创建日期:2007-3-23


* 修改记录:


***********************************************************/


package org.lhj.cool.junit;




/**


* @author Administrator


*/


public class CoolClass


{




/**


* constructor


*/


public CoolClass()


{


super();


}




/**


* @param inputStr -the string need to be reverse.


* @return null if the inputStr is "",others the reverse string of the inputStr.


*/


public String reverseString(String inputStr)


{


if (null == inputStr)


{


throw new NullPointerException("Error:the input string is null.");


}


if ("".equals(inputStr))


{


return null;


}




int length = inputStr.length();


char[] outputChars = new char[length];


for (int i = 0; i < length; i++)


{


outputChars[i] = inputStr.charAt(length - i - 1);


}




return new String(outputChars);


}




/**


* this method is for test.


* @param args


*/


public static void main(String[] args)


{


//set up the invironment


CoolClass testClass = new CoolClass();




//test the null param


try


{


testClass.reverseString(null);


System.out.println("Error:expect throw nullPointerExceptioin but not.");


}


catch (NullPointerException e)


{


System.out.println("Succeed:test the null param for reverseString succeed.");


}




//test the "" param


if (!(null == testClass.reverseString("")))


{


System.out.println("Error:expect return the null value but not.");


}


else


{


System.out.println("Succeed:test the "" param for reverseString succeed.");


}




//test the "aaAA" param


if (!"AAaa".equals(testClass.reverseString("aaAA")))


{


System.out.println("Error:expect return AAaa but not.");


}


else


{


System.out.println("Succeed:test the aaAA param for reverseString succeed.");


}




//test the "AAaa" param


if (!"aaAA".equals(testClass.reverseString("AAaa")))


{


System.out.println("Error:expect return aaAA but not");


}


else


{


System.out.println("Succeed:test the AAaa param for reverseString succeed.");


}




//the other tests...




//tear down the environment


testClass = null;


}




}



欲测试类：


/************************************************************


* Project Name: lhjTest


* File Name : UseCoolClass.java


* File Desc : UseCoolClass.java


* Author : Administrator


* Create : 2007-3-25


* Modify:


***********************************************************/


package org.lhj.cool.mock;




import org.lhj.cool.junit.CoolClass;




/**


* @author Administrator


*/


public class UseCoolClass


{


private CoolClass cool;




public void setCoolClass(CoolClass cool)


{


this.cool = cool;


}




public String reverseString(String inputStr) throws NullPointerException


{


return cool.reverseString(inputStr);


}




}



测试代码如下：


/************************************************************


* Project Name: lhjTest


* File Name : UseCoolClassJTest.java


* File Desc : UseCoolClassJTest.java


* Author : Administrator


* Create : 2007-3-25


* Modify:


***********************************************************/


package org.lhj.cool.mock;




import junit.framework.TestCase;




import org.easymock.MockControl;


import org.easymock.classextension.MockClassControl;


import org.lhj.cool.junit.CoolClass;


import org.lhj.cool.mock.UseCoolClass;




/**


* @author Administrator


*/


public class UseCoolClassJTest extends TestCase


{


private MockControl ctrl;




private CoolClass cool;




private UseCoolClass testClass;




/* (non-Javadoc)


* @see junit.framework.TestCase#setUp()


*/


protected void setUp() throws Exception


{


super.setUp();




ctrl = MockClassControl.createControl(CoolClass.class);


cool = (CoolClass) ctrl.getMock();




testClass = new UseCoolClass();


testClass.setCoolClass(cool);


}




/* (non-Javadoc)


* @see junit.framework.TestCase#tearDown()


*/


protected void tearDown() throws Exception


{


super.tearDown();


}




/**


* Test method for {@link org.lhj.cool.mock.UseCoolClass#reverseString(java.lang.String)}.


*/


public void testReverseString()


{


ctrl.expectAndThrow(cool.reverseString(null), new NullPointerException());


ctrl.expectAndReturn(cool.reverseString(""), null);


ctrl.expectAndReturn(cool.reverseString("AAaa"), "aaAA");


ctrl.expectAndReturn(cool.reverseString("aaAA"), "AAaa");


ctrl.replay();




try


{


testClass.reverseString(null);


fail();


}


catch (NullPointerException e)


{


//donothing


}


assertNull(testClass.reverseString(""));


assertEquals("aaAA", testClass.reverseString("AAaa"));


assertEquals("AAaa", testClass.reverseString("aaAA"));




ctrl.verify();


}




}



这里操作步骤跟easymock一模一样，所以就不多说了。

如果读者能够从第一篇一直读到这里，并且把每个例子都试了一下，相信要进行单元测试已经没用技术上的问题了。剩下的问题就是如何高效地进行单元测试，如何提高单元测试的测试质量，这些问题已经不在本系列文章的谈论范围之内，有时间再写一下。