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>