我正在尝试使用磁贴集成创建一个简单的Spring 3 MVC应用程序。
当我尝试构建应用程序时，我收到此错误消息（为简洁而截断）：
java.lang.NullPointerException
at org.apache.commons.digester.Digester.getXMLReader(Digester.java:1058)
at org.apache.commons.digester.Digester.parse(Digester.java:1887)
at org.apache.tiles.definition.digester.DigesterDefinitionsReader.read(DigesterDefinitionsReader.java:329)
at org.apache.tiles.definition.dao.BaseLocaleUrlDefinitionDAO.loadDefinitionsFromURL(BaseLocaleUrlDefinitionDAO.java:276)
at org.apache.tiles.definition.dao.CachingLocaleUrlDefinitionDAO.loadDefinitionsFromURLs(CachingLocaleUrlDefinitionDAO.java:251)
我错过了一些必需的图书馆吗？
我在WEB-INF / lib文件夹中有以下jar。
commons-beanutils-1.8.0.jar
commons-digester-2.0.jar
org.springframework.asm-3.1.1.RELEASE.jar
org.springframework.beans-3.1.1.RELEASE.jar
org.springframework.context-3.1.1.RELEASE.jar
org.springframework.core-3.1.1.RELEASE.jar
org.springframework.expression-3.1.1.RELEASE.jar
org.springframework.web.servlet-3.1.1.RELEASE.jar
org.springframework.web-3.1.1.RELEASE.jar
tiles-api-2.2.2.jar
tiles-core-2.2.2.jar
tiles-jsp-2.2.2.jar
tiles-servlet-2.2.2.jar
tiles-template-2.2.2.jar
log4j-1.2.16.jar
slf4j-api-1.6.4.jar
slf4j-log4j12-1.6.4.jar
WEB-INF / web.xml中
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>SpringMVC</display-name>
<servlet>
<servlet-name>spring</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>spring</servlet-name>
<url-pattern>*.html</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
WEB-INF /弹簧servlet.xml中
<?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:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
<!-- Scans within the base package of the application for @Components to configure as beans -->
<!-- @Controller, @Service, @Configuration, etc. -->
<context:component-scan base-package="xyz.sample.baremvc" />
<!-- Enables the Spring MVC @Controller programming model -->
<mvc:annotation-driven />
<bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView" />
</bean>
<bean id="tilesConfigurer" class="org.springframework.web.servlet.view.tiles2.TilesConfigurer">
<property name="definitions">
<list>
<value>/WEB-INF/tiles.xml</value>
</list>
</property>
</bean>
WEB-INF / tiles.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE tiles-definitions PUBLIC
"-//Apache Software Foundation//DTD Tiles Configuration 2.0//EN"
"http://tiles.apache.org/dtds/tiles-config_2_0.dtd">
<tiles-definitions>
<definition name="base.definition" template="/WEB-INF/views/layout.jsp">
<put-attribute name="title" value="" />
<put-attribute name="header" value="/WEB-INF/views/header.jsp" />
<put-attribute name="menu" value="/WEB-INF/views/menu.jsp" />
<put-attribute name="body" value="" />
<put-attribute name="footer" value="/WEB-INF/views/footer.jsp" />
</definition>
<definition name="contact" extends="base.definition">
<put-attribute name="title" value="Contact Manager" />
<put-attribute name="body" value="/WEB-INF/views/contact.jsp" />
</definition>
</tiles-definitions>
由于
答案 0 :(得分：6)
使用commons-digester-1.8.jar和tile 2.2.2，版本2.0的commons-digester对于sax来说是错误的。
编辑：我用来解决问题的额外的pom 这是解决最初的http请求，这是一个已知的问题（请注意我使用的是jdk 1.6）这里有一个额外的pom来使它工作：
<!-- Note: tiles 2.2 uses commons-digester 2.0 which is buggy with sax
(http request will fail the first time) using version 1.8 to solve the issue -->
<dependency>
<groupId>commons-digester</groupId>
<artifactId>commons-digester</artifactId>
<version>1.8</version>
</dependency>
<dependency>
<groupId>org.apache.tiles</groupId>
<artifactId>tiles-servlet</artifactId>
<version>${apacheTiles.version}</version>
<exclusions>
<exclusion>
<groupId>commons-digester</groupId>
<artifactId>commons-digester</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.apache.tiles</groupId>
<artifactId>tiles-jsp</artifactId>
<version>${apacheTiles.version}</version>
</dependency>
$ {apacheTiles.version}为2.2.2，spring版本为3.0.5.RELEASE
答案 1 :(得分：1)
我假设com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl是从第三方库中引用的。确保它是从Sun的jre库中引用的。
如果您使用的是maven，请尝试从类路径中排除任何不需要的库。
修改
查看org.apache.commons.digester.parser.XercesParser
中的这段代码 public static SAXParser newSAXParser(Properties properties)
throws ParserConfigurationException,
SAXException,
SAXNotSupportedException {
SAXParserFactory factory =
(SAXParserFactory)properties.get("SAXParserFactory");
if (versionNumber == null){
versionNumber = getXercesVersion();
version = new Float( versionNumber ).floatValue();
}
// Note: 2.2 is completely broken (with XML Schema).
if (version > 2.1) {
configureXerces(factory);
return factory.newSAXParser();
} else {
SAXParser parser = factory.newSAXParser();
configureOldXerces(parser,properties);
return parser;
}
}
答案 2 :(得分：0)
用commons-digester-1.7替换commons-digester-2.0 for tiles 2.2.2来解决这个问题。