struts2配置 常见异常处理

开发环境：JDK6+tomcat6+struts-2.1.6（最新）
（tomcat一定是5.5以上，jdk为1.5以上）
struts2下载地址：http://struts.apache.org/

最基本的小程序用到jar包，struts2-core.jar，commons-logging.jar，freemarker.jar，ognl.jar，xwork.jar
（注意了：struts2-core-2.1.6.jar时要附加上两个包，commons-fileupload.jar 和 commons-io.jar ）
还有了在配置web.xml文件时记得不要在用这个过滤器了，

<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>，
新版本中都是过时的了，采取该过滤器，
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>。

安装实例配置好以后，开始运行，可是出现一下错误：

严重: Exception starting filter struts2

Unable to load configuration. - bean - jar:file:/E:/struts2/struts2/WebRoot/WEB-INF/lib/struts2-core-2.1.6.jar!/struts-default.xml:46:178

at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:58)

at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:360)

at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:403)

at org.apache.struts2.dispatcher.FilterDispatcher.init(FilterDispatcher.java:190)

at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)

at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)

at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)

at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3709)

at org.apache.catalina.core.StandardContext.start(StandardContext.java:4363)

at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)

at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)

at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)

at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)

at org.apache.catalina.core.StandardService.start(StandardService.java:516)

at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)

at org.apache.catalina.startup.Catalina.start(Catalina.java:578)

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:288)

at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)

Caused by: Unable to load bean: type:org.apache.struts2.dispatcher.multipart.MultiPartRequest class:org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest - bean - jar:file:/E:/struts2/struts2/WebRoot/WEB-INF/lib/struts2-core-2.1.6.jar!/struts-default.xml:46:178

at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:222)

at org.apache.struts2.config.StrutsXmlConfigurationProvider.register(StrutsXmlConfigurationProvider.java:101)

at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:165)

at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:55)

... 21 more

Caused by: java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileUploadException

at java.lang.Class.getDeclaredConstructors0(Native Method)

at java.lang.Class.privateGetDeclaredConstructors(Class.java:2389)

at java.lang.Class.getDeclaredConstructors(Class.java:1836)

at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.register(XmlConfigurationProvider.java:212)

... 24 more

Caused by: java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileUploadException

at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387)

at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)

at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)

... 28 more

2009-2-16 15:07:42 org.apache.catalina.core.StandardContext start

严重: Error filterStart

2009-2-16 15:07:42 org.apache.catalina.core.StandardContext start

严重: Context [/struts2] startup failed due to previous errors
错误中指明struts-default.xml:46:178，struts2-core.jar包中的struts-default文件的46行有问题，于是我打开struts-default.xml，46行为：
<bean type="org.apache.struts2.dispatcher.multipart.MultiPartRequest" name="struts" class="org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest" scope="default"/>
发现要加载org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest。查看这个类的源文件

其中前面有这样几句 ：
package org.apache.struts2.dispatcher.multipart;
import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Enumeration;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.fileupload.FileItem;

import org.apache.commons.fileupload.FileUploadException;

import org.apache.commons.fileupload.RequestContext;

import org.apache.commons.fileupload.disk.DiskFileItem;

import org.apache.commons.fileupload.disk.DiskFileItemFactory;

import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.struts2.StrutsConstants;

import com.opensymphony.xwork2.inject.Inject;

import com.opensymphony.xwork2.util.logging.Logger;

import com.opensymphony.xwork2.util.logging.LoggerFactory;

public class JakartaMultiPartRequest implements MultiPartRequest {

//下面略

在这个类中必须引入org.apache.commons.fileupload.*;

而错误也许没有加载这个文件上传包所以找不到类 。

于是我就把commons-fileupload-1.2.1.jar 和 commons-io-1.3.2.jar 导入，结果错误解决了。