本人转载于：  http://mgc.name/article.asp?id=811

1.JUnit4.4引入了Hamcrest框架，Hamcest提供了一套匹配符Matcher，这些匹配符更接近自然语言，可读性高，更加灵活；
2.使用全新的断言语法：assertThat，结合Hamcest提供的匹配符，只用这一个方法，就可以实现所有的测试；
3.assertThat语法如下：
    assertThat(T actual, Matcher matcher);
    assertThat(String reason, T actual, Matcher matcher);
    其中actual为需要测试的变量，matcher为使用Hamcrest的匹配符来表达变量actual期望值的声明；
4.注意事项：
    a.必须导入JUnit4.4之后的版本才能使用assertThat方法；
    b.不需要继承TestCase类，但是需要测试方法前必须加“@Test”。
    c.需要导入Hamcrest类库:hamcrest-core-1.3.0RC2.jar  |   hamcrest-library-1.3.0RC2.jar
 
3、使用assertThat
a)          assertThat( n, allOf( greaterThan(1), lessThan(15) ) );
assertThat( n, anyOf( greaterThan(16), lessThan(8) ) );
assertThat( n, anything() );
assertThat( str, is( "bjsxt" ) );
assertThat( str, not( "bjxxt" ) );
b)         assertThat( str, containsString( "bjsxt" ) );
assertThat( str, endsWith("bjsxt" ) ); 
assertThat( str, startsWith( "bjsxt" ) ); 
assertThat( n, equalTo( nExpected ) ); 
assertThat( str, equalToIgnoringCase( "bjsxt" ) ); 
assertThat( str, equalToIgnoringWhiteSpace( "bjsxt" ) );
c)          assertThat( d, closeTo( 3.0, 0.3 ) );
assertThat( d, greaterThan(3.0) );
assertThat( d, lessThan (10.0) );
assertThat( d, greaterThanOrEqualTo (5.0) );
assertThat( d, lessThanOrEqualTo (16.0) );
d)         assertThat( map, hasEntry( "bjsxt", "bjsxt" ) );
assertThat( iterable, hasItem ( "bjsxt" ) );
assertThat( map, hasKey ( "bjsxt" ) );
assertThat( map, hasValue ( "bjsxt" ) );