今天在maven工具構建一個java web(暫時只用到tomcat+spring)的工程時，遇到了幾個小問題，由於以前也碰到過，所以想記錄一下，以備未來查閱：
（A）tomcat啟動的時候報這個錯，貌似是不能解析xml檔案，然後到網上找了一下解答

org.springframework.beans.factory.BeanDefinitionStoreException: Parser configuration exception parsing XML from URL [file:/E:/hefei_spring_mybatis_mvc/.metadata/.plugins/org.eclipse
 
.wst.server.core/tmp0/wtpwebapps/spring_chapter05/WEB-INF/classes/beans.xml]; nested exception is javax.xml.parsers.ParserConfigurationException: Unable to validate using XSD: Your JAXP provider [[email protected]] does not support XML Schema. Are you running on Java 1.4 with Apache Crimson? Upgrade to Apache Xerces (or Java 1.5) for full XSD support.
 

    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:406)
    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:605)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:509)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:446)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:328)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4973)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5467)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: javax.xml.parsers.ParserConfigurationException: Unable to validate using XSD: Your JAXP provider [org.apache.xerces.jaxp.DocumentBuilderFactoryImpl@40f52e28] does not support XML Schema. Are you running on Java 1.4 with Apache Crimson? Upgrade to Apache Xerces (or Java 1.5) for full XSD support.
    at org.springframework.beans.factory.xml.DefaultDocumentLoader.createDocumentBuilderFactory(DefaultDocumentLoader.java:102)
    at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:71)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadDocument(XmlBeanDefinitionReader.java:429)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:391)
    ... 22 more
Caused by: java.lang.IllegalArgumentException: http://java.sun.com/xml/jaxp/properties/schemaLanguage
    at org.apache.xerces.jaxp.DocumentBuilderFactoryImpl.setAttribute(DocumentBuilderFactoryImpl.java:118)
    at org.springframework.beans.factory.xml.DefaultDocumentLoader.createDocumentBuilderFactory(DefaultDocumentLoader.java:99)
    ... 25 more

解決方法如下：
（1）雙擊tomcat跳出如下介面,點選open launch configuration,如下圖

（2）然後在Arguments選項卡的VM argument中的框中複製如下引數,儲存並重新執行：

-Djavax.xml.parsers.DocumentBuilderFactory=com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl
-Djavax.xml.parsers.DocumentBuilderFactory=com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl

（B）還有一個問題是我經常犯得問題，就是maven工程的pom.xml明明寫了相關jar的依賴，但是在web工程啟動的時候報找不到相關類的錯誤(專案背景是在maven下構建web工程的時候),這個時候檢視工作區下的相應工程的/WEB-INF/lib路徑下，並沒有相關的jar包

解決方法如下：

• 右鍵點選專案選擇Properties選擇Deployment Assembly,在右邊點選Add按鈕，在彈出的視窗中選擇Java Build Path Entries
  
• 點選Next，選擇Maven Dependencies
• 點選Finish，然後可以看到已經把Maven Dependencies新增到Web應用結構中了
  

（c）最後一個問題就是，在解決maven工程上有紅叉的時候解決思路，點選Window–>show veiw–>Markers)，檢視錯誤的詳細資訊，可以檢視一下錯誤的原因。