的对象相关事件，方法包括测试开始startTest(Test test)，测试结束endTest(Test test),错误，增加异常addError(Test test,Throwable t)和增加失败addFailure(Test test,AssertionFailedError t)
TestFailure失败类是个―失败‖状况的收集类，解释每次测试执行过程中出现的异常情况。其toString()方法返回―失败‖状况的简要描述 4. 利用Junit开发一个简单的Java程序
（1）File-new-Java project，名称为“HelloWorldWithJUnit” 建立两个文件夹，分别为src和junittest src 存放实现主要功能的文件 junittest 存放测试功能文件
（2）创建测试类
选中“HelloWorldWithJUnit”项目中的junittest包文件夹，new-other-Junit-Junit Test Case
右键并选择
（3）选择“next”，在New Junit Test Case中的name中输入“HelloWorldTest”，在package中输入“junittest”，然后单击“finish”。
（4）现在初步计划被测试文件功能非常简单，只有一个方法ReturnValue，作用是返回“HelloWorld”，所以测试类中有对ReturnValue这个方法进行测试的类。当然，测试要能进行，该测试类必须为主类，存在main方法。HelloWorldTest.java的源代码如下：
选择run-run as-Junit test
弹出一个Junit窗口，发现在该窗口中有一个红条，这说明存在错误。 （5）创建HelloWorld类
建立一个HelloWorld类，并输入以下代码：
（6）在HelloWorldTest.java中加入import src.*;
此时以Junit测试的方式来运行HelloWorldTest.java，出现了含有绿色的窗口，测试成功。
assertEquals
public static void assertEquals([java.lang.String message], java.lang.Object expected, java.lang.Object actual)
Asserts that two objects are equal. If they are not, an AssertionError is thrown with the given message. If expected and actual are null, they are considered equal.
Parameters:
message - the identifying message for the AssertionError (null okay) expected - expected value actual - actual value
assertFalse
public static void assertFalse(java.lang.String message, boolean condition)
Asserts that a condition is false. If it isn't it throws an AssertionError with the given
message. Parameters:
message - the identifying message for the AssertionError (null okay) condition - condition to be checked
assertTrue
public static void assertTrue(java.lang.String message, boolean condition)
Asserts that a condition is true. If it isn't it throws an AssertionError with the given
message. Parameters:
message - the identifying message for the AssertionError (null okay) condition - condition to be checked
assertNull
public static void assertNull(java.lang.String message, java.lang.Object object)
Asserts that an object is null. If it is not, an AssertionError is thrown with the given
message.
Parameters:
message - the identifying message for the AssertionError (null okay) object - Object to check or null
assertNotNull
public static void assertNotNull(java.lang.String message, java.lang.Object object)
Asserts that an object isn't null. If it is an AssertionError is thrown with the given
message. Parameters:
message - the identifying message for the AssertionError (null okay)
object - Object to check or null
assertSame
public static void assertSame([java.lang.String message], java.lang.Object expected, java.lang.Object actual)
Asserts that two objects refer to the same object. If they are not, an AssertionError is
thrown with the given message. Parameters:
message - the identifying message for the AssertionError (null okay)
expected - the expected object
actual - the object to compare to expected
assertNotSame
public static void assertNotSame(java.lang.String message, java.lang.Object unexpected, java.lang.Object actual)
Asserts that two objects do not refer to the same object. If they do refer to the same object, an AssertionError is thrown with the given message. Parameters:
message - the identifying message for the AssertionError (null okay) unexpected - the object you don't expect
actual - the object to compare to unexpected