配置文件放在class目錄下：
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring.xml");
WEB-INF下：
ApplicationContext applicationContext = new FileSystemXmlApplicationContext("WebRoot/WEB-INF/spring.xml");
多個文件可用*表示
ApplicationContext applicationContext = new FileSystemXmlApplicationContext("WebRoot/WEB-INF/spring.xml");
注解方式：
class：
@ContextConfiguration(locations={"classpath:spring.xml"})
WEB-INF：
@ContextConfiguration(locations={"file:WebRoot/WEB-INF/spring.xml"})
使用注解時，Junit報錯：
java.lang.NoSuchFieldError: NULL
at org.junit.runners.ParentRunner.<init>(ParentRunner.java:48)
at org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:59)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.<init>(SpringJUnit4ClassRunner.java:104)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.junit.internal.requests.ClassRequest.buildRunner(ClassRequest.java:33)
at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:28)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.<init>(JUnit4TestReference.java:28)
經檢查是jar包沖突，我在建項目的時候，myeclipse有自動加入junit4，而后面我又自己加入Junit4.8.1。
如果報以下錯誤，則是junit包版本太低，需要4.5或以上的版本
Caused by: java.lang.ClassNotFoundException: org.junit.runners.BlockJUnit4ClassRunner
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
