为啥junit测试问题

Question

package Test;import static org.junit.Assert.*;import javax.annotation.Resource;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import com.imooc.aop.StudentDao;@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration("classpath:applicationContext.xml")public class SpringAOPDemo {	/*@Resource(name="studentDao")*/	@Resource(name="studentDao")	private StudentDao studentDao;	@Test	public void test() {				studentDao.save();		studentDao.update();		studentDao.delete();		studentDao.find();	}}

java.lang.Exception: No runnable methods	at org.junit.runners.BlockJUnit4ClassRunner.validateInstanceMethods(BlockJUnit4ClassRunner.java:191)	at org.junit.runners.BlockJUnit4ClassRunner.collectInitializationErrors(BlockJUnit4ClassRunner.java:128)	at org.junit.runners.ParentRunner.validate(ParentRunner.java:416)	at org.junit.runners.ParentRunner.<init>(ParentRunner.java:84)	at org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:65)	at org.junit.internal.builders.JUnit4Builder.runnerForClass(JUnit4Builder.java:10)	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)	at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)	at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:33)	at org.junit.internal.requests.FilterRequest.getRunner(FilterRequest.java:36)	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createFilteredTest(JUnit4TestLoader.java:80)	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:71)	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:46)	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:522)	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)

public interface StudentDao {	public void save();		public void find();			public void update();		public void delete();	}

package com.imooc.aop;public class StudentDaoImpl implements StudentDao {	@Override	public void save() {				System.out.println("保存学生......");	}	@Override	public void find() {				System.out.println("学生查询......");	}	@Override	public void update() {				System.out.println("修改学生......");	}	@Override	public void delete() {			System.out.println("删除学生......");	}}

package com.imooc.aop.advice;import java.lang.reflect.Method;import org.springframework.aop.MethodBeforeAdvice;public class MyBeforeAdvice implements MethodBeforeAdvice{	@Override	public void before(Method method, Object[] args, Object target) throws Throwable {		System.out.println("前置增强================");	}	}

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"	xmlns:p="http://www.springframework.org/schema/p"	xmlns:aop="http://www.springframework.org/schema/aop"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xsi:schemaLocation="        http://www.springframework.org/schema/beans         http://www.springframework.org/schema/beans/spring-beans.xsd        http://www.springframework.org/schema/aop         http://www.springframework.org/schema/aop/spring-aop.xsd">                <!-- 配置目标类 -->        <bean id="studentDao" class="com.imooc.aop.StudentDaoImpl"	/>                <!-- 前置通知类型 -->        <bean id="myBeforeAdvice" class="com.imooc.aop.advice.MyBeforeAdvice" />                <!-- Spring的AOP  产生代理对象-->        <bean id="studentDaoProxy" class="org.springframework.aop.framework.ProxyFactoryBean">        <!-- target:代理的目标对象 -->        	<property name="target" ref="studentDao" />        	<!-- proxyInterfaces:代理要实现的接口 -->        	<property name="proxyInterfaces" value="com.imooc.aop.StudentDao" />        	<!-- 采用拦截的名称 -->        	<property name="interceptorNames" value="myBeforeAdvice" />        </bean></beans>