Velocity 怎么搭建环境呢，今天搭了一个时没搭出来，请求帮助？? 400 报错

velocity 只是一个 jar 包，引入 jar 包后，在 web.xml 中配置如下即可

<servlet>
	<servlet-name>velocity</servlet-name>
	<servlet-class>org.apache.velocity.servlet.VelocityServlet</servlet-class>
	<load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
	<servlet-name>velocity</servlet-name>
	<url-pattern>*.vm</url-pattern>
</servlet-mapping>

这样配置一启动就报这个错啊！

at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30)

2011-11-14 22:24:24 org.apache.catalina.core.AprLifecycleListener init
信息: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Java\jdk1.6\bin;E:\tomcat-6.0.33\bin
2011-11-14 22:24:24 org.apache.coyote.http11.Http11Protocol init
信息: Initializing Coyote HTTP/1.1 on http-8080
2011-11-14 22:24:24 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 405 ms
2011-11-14 22:24:24 org.apache.catalina.core.StandardService start
信息: Starting service Catalina
2011-11-14 22:24:24 org.apache.catalina.core.StandardEngine start
信息: Starting Servlet Engine: Apache Tomcat/6.0.33
2011-11-14 22:24:24 org.apache.catalina.startup.HostConfig deployDescriptor
信息: Deploying configuration descriptor host-manager.xml
2011-11-14 22:24:25 org.apache.catalina.startup.HostConfig deployDescriptor
信息: Deploying configuration descriptor manager.xml
2011-11-14 22:24:25 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory docs
2011-11-14 22:24:25 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory examples
2011-11-14 22:24:25 org.apache.catalina.core.ApplicationContext log
信息: ContextListener: contextInitialized()
2011-11-14 22:24:25 org.apache.catalina.core.ApplicationContext log
信息: SessionListener: contextInitialized()
2011-11-14 22:24:25 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory ROOT
2011-11-14 22:24:25 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory valocity
2011-11-14 22:24:25 org.apache.catalina.core.ApplicationContext log
信息: Marking servlet velocity as unavailable
2011-11-14 22:24:25 org.apache.catalina.core.StandardContext loadOnStartup
严重: Servlet /valocity threw load() exception
java.lang.InstantiationException
	at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:30)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
	at java.lang.Class.newInstance0(Class.java:355)
	at java.lang.Class.newInstance(Class.java:308)
	at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1116)
	at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:993)
	at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4421)
	at org.apache.catalina.core.StandardContext.start(StandardContext.java:4734)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)
	at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1079)
	at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:1002)
	at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:506)
	at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1317)
	at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)
	at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1065)
	at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
	at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
	at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
	at org.apache.catalina.core.StandardService.start(StandardService.java:525)
	at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
	at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
2011-11-14 22:24:25 org.apache.coyote.http11.Http11Protocol start
信息: Starting Coyote HTTP/1.1 on http-8080
2011-11-14 22:24:25 org.apache.jk.common.ChannelSocket init
信息: JK: ajp13 listening on /0.0.0.0:8009
2011-11-14 22:24:25 org.apache.jk.server.JkMain start
信息: Jk running ID=0 time=0/32  config=null
2011-11-14 22:24:25 org.apache.catalina.startup.Catalina start
信息: Server startup in 654 ms

所有的JAR包都放进去了！

<load-on-startup>1</load-on-startup> 不要这个启动就不报错，但访问报错！

严重: Servlet /valocity threw load() exception

拼写错了，你改正确试试  veloctiy