关于spring“通配符的匹配很全面, 但无法找到元素 'context:component-scan' 的声明”的错误

关于spring配置的问题

近日学习spring时遇到了这个问题：

org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 12 in XML document from URL [file:/F:/workspace/spring/target/classes/applicationContext.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 12; columnNumber: 55; cvc-complex-type.2.4.c: 通配符的匹配很全面, 但无法找到元素 'context:component-scan' 的声明。

报错如下：

17:21:22,400 ERROR main context.ContextLoader:331 - Context initialization failed
org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 14 in XML document from URL [file:/F:/workspace/spring/target/classes/applicationContext.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 14; columnNumber: 54; cvc-complex-type.2.4.c: 通配符的匹配很全面, 但无法找到元素 'context:component-scan' 的声明。
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:399)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:336)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:304)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:181)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:217)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:125)
at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:94)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:129)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:537)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:452)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4135)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4630)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:785)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:445)
at org.apache.catalina.startup.Embedded.start(Embedded.java:825)
at org.codehaus.mojo.tomcat.AbstractRunMojo.startContainer(AbstractRunMojo.java:558)
at org.codehaus.mojo.tomcat.AbstractRunMojo.execute(AbstractRunMojo.java:255)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:133)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:108)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:76)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:116)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:361)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:157)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)

查了好多资料，发现是applicationContext.xml文件有点小问题。

报错时的文件头：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">

添加了一些schemaLocation：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
<span style="white-space:pre">	</span>xmlns:context="http://www.springframework.org/schema/context"
<span style="white-space:pre">	</span>xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
<span style="white-space:pre">	</span>xmlns:aop="http://www.springframework.org/schema/aop"
<span style="white-space:pre">	</span>xmlns:mvc="http://www.springframework.org/schema/mvc"
<span style="white-space:pre">	</span>xmlns:jee="http://www.springframework.org/schema/jee"
<span style="white-space:pre">	</span>xmlns:tx="http://www.springframework.org/schema/tx"
<span style="white-space:pre">	</span>xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

就OK了~(^__^) ，注:不要拷贝上面配置，要根据自己项目缺少的schema而添加

原因：

我这个原因是有些“schemaLocation”没有写。把对应的加上就可以了。

其根本原因是spring启动是时候要通过相应的xsd文件来检验xml文件，找不到相应的xsd文件的时候就会报错。

那么spring是如何加载xsd文件的呢？

spring是默认从本地加载xsd文件的，举个栗子：我们打开spring-context的jar包，找到spring.schemas这个文件

然后在org/springframework/context/config目录下可以找到这些xsd文件。默认加载的就是这些文件。

spring这一点细节做得比较好，把所有版本的xsd文件都放进来了，无论在spring配置文件中写哪个版本的schemaLocation，都能找得到。如果不写schemaLocation的版本号是，默认是当前版本。

解决办法：

检查spring配置文件里有没有配相应的schema配置，补充上就可以了