我尝试用 jsf 编写第一个 maven web 应用程序。我遇到了问题。我试图找到答案。每次部署我都会得到下一个堆栈跟踪
java.lang.NullPointerException
com.sun.faces.context.flash.ELFlash.getPhaseMapForReading(ELFlash.java:736)
com.sun.faces.context.flash.ELFlash.isEmpty(ELFlash.java:465)
com.sun.faces.facelets.util.DevTools.writeVariables(DevTools.java:318)
com.sun.faces.facelets.util.DevTools.writeVariables(DevTools.java:208)
com.sun.faces.facelets.util.DevTools.debugHtml(DevTools.java:123)
com.sun.faces.renderkit.RenderKitUtils.renderHtmlErrorPage(RenderKitUtils.java:1139)
com.sun.faces.context.ExceptionHandlerImpl.throwIt(ExceptionHandlerImpl.java:249)
com.sun.faces.context.ExceptionHandlerImpl.handle(ExceptionHandlerImpl.java:136)
com.sun.faces.lifecycle.Phase.doPhase(Phase.java:119)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:311)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.12 logs.
我的绒球
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>by.bsuir.transport</groupId>
<artifactId>transportApp</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<properties>
<endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java-version>1.6</java-version>
</properties>
<repositories>
<repository>
<id>prime-repo</id>
<name>PrimeFaces Maven Repository</name>
<url>http://repository.primefaces.org</url>
<layout>default</layout>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.myfaces.core</groupId>
<artifactId>myfaces-api</artifactId>
<version>2.1.10</version>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.primefaces</groupId>
<artifactId>primefaces</artifactId>
<version>3.5</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8.2</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
<compilerArguments>
<endorseddirs>${endorsed.dir}</endorseddirs>
</compilerArguments>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.1.1</version>
</plugin>
</plugins>
</build>
</project>
我的 web.xml
<?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_3_0.xsd"
id="WebApp_ID" version="3.0" metadata-complete="true">
<welcome-file-list>
<welcome-file>index.xhtml</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>Faces Servlet</servlet-name>
<servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.xhtml</url-pattern>
</servlet-mapping>
<context-param>
<param-name>javax.faces.PROJECT_STAGE</param-name>
<param-value>Development</param-value>
</context-param>
<context-param>
<param-name>javax.faces.DEFAULT_SUFFIX</param-name>
<param-value>.xhtml</param-value>
</context-param>
<context-param>
<param-name>facelets.SKIP_COMMENTS</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<param-name>javax.faces.FACELETS_VIEW_MAPPINGS</param-name>
<param-value>.xhtml</param-value>
</context-param>
<context-param>
<param-name>javax.faces.DATETIMECONVERTER_DEFAULT_TIMEZONE_IS_SYSTEM_TIMEZONE</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>client</param-value>
</context-param>
<context-param>
<param-name>org.apache.myfaces.ALLOW_JAVASCRIPT</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<param-name>org.apache.myfaces.AUTO_SCROLL</param-name>
<param-value>true</param-value>
</context-param>
<context-param>
<param-name>org.apache.myfaces.DETECT_JAVASCRIPT</param-name>
<param-value>false</param-value>
</context-param>
<context-param>
<param-name>org.apache.myfaces.PRETTY_HTML</param-name>
<param-value>true</param-value>
</context-param>
</web-app>
这个问题的原因可能是什么&