Spring框架中的Ioc

在spring框架中遇到了一个错误提醒：

一、.NoClassDefFoundError： 这个英文代表没有找到class,方法产生的额错误；

解决方案：这个问题出现一般有两个可能：1）导入的包有重复的；2）没有导入一个特定的包： org/apache/commons/logging/LogFactory ;只要导入这个路径下的包即可（commons-logging.jar）这是我在spring框架中学习所遇到的问题

java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.<init>(DefaultSingletonBeanRegistry.java:81)
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.<init>(FactoryBeanRegistrySupport.java:43)
    at org.springframework.beans.factory.support.AbstractBeanFactory.<init>(AbstractBeanFactory.java:176)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.<init>(AbstractAutowireCapableBeanFactory.java:159)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.<init>(AbstractAutowireCapableBeanFactory.java:170)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.<init>(DefaultListableBeanFactory.java:165)
    at org.springframework.beans.factory.xml.XmlBeanFactory.<init>(XmlBeanFactory.java:78)
    at org.springframework.beans.factory.xml.XmlBeanFactory.<init>(XmlBeanFactory.java:67)
    at com.ys.study.hellowordTest.testhello(hellowordTest.java:19)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClassInternal(Unknown Source)
    ... 32 more

二、.NoSuchBeanDefinitionException: No bean named 'hello' is defined 遇到这种情况就代表bean的名字和你文件中的名字不同所导致的；你可以检查一下你的java文件红色部分和.xml文件的红色部分是不是不一样才导致这个错误；若两个不一样就会产生我文章中出现的错误；

解决方案：把java文件中和 .xml文件中红色的部分改成一样的就可以了

我的java 文件：

public class hellowordTest {
    @Test
    public void testhello() throws Exception {
        helloword hello = null;
        // -----------------
        Resource resource = new ClassPathResource("applicationContext.xml");
        // ------------
        // 启动容器
        BeanFactory beanfaction = new XmlBeanFactory(resource);
        // 从spring容器中获得bean
        hello = (helloword) beanfaction.getBean("hello");
        hello.heiio();
    }
}

我的.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       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">

<!-- bean definitions here -->
<bean id="helloword" class="com.ys.study.helloword"></bean>
</beans>

org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'hello' is defined
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:570)
at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1108)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:278)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at com.ys.study.hellowordTest.testhello(hellowordTest.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)