从Tomcat 7迁移到8时的Jsf实现版本NullPointerException

Question

我目前使用的是JSF2.2.7和Icefaces版本4.0.0。我的项目在Tomcat7上运行，但在Tomcat8上运行时遇到了麻烦。我得到一个空指针异常，因为icefaces代码中的一个方法似乎要检查正在使用的jsf的当前版本。这总是返回null，我似乎没有设置正确的JSF实现。堆栈跟踪如下：

/**
 * Determine whether the current JSF implementation is version 2.2
 * @return true if JSF implementation is 2.2
 */
public static boolean isJSF22() {
    return FacesContext.class.getPackage().getImplementationVersion().startsWith("2.2");
}

    <?xml version="1.0"?>
     <project
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
        xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <modelVersion>4.0.0</modelVersion>
        <groupId>oag.com.reference</groupId>
        <artifactId>web</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>ReferenceDataWeb </name>
        <packaging>war</packaging>
        <description>Reference data web project.</description>


    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <sonar.core.codeCoveragePlugin>jacoco</sonar.core.codeCoveragePlugin>
        <sonar.dynamicAnalysis>reuseReports</sonar.dynamicAnalysis>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                            <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.jacoco</groupId>
                <artifactId>jacoco-maven-plugin</artifactId>
                <version>0.7.0.201403182114</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>prepare-agent</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <destFile>${sonar.jacoco.reportPath}</destFile>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <dependency>
            <groupId>org.icefaces</groupId>
            <artifactId>icefaces</artifactId>
            <version>4.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.icefaces</groupId>
            <artifactId>icefaces-ace</artifactId>
            <version>4.0.0</version>
        </dependency>

        <dependency>
            <groupId>org.icepush</groupId>
            <artifactId>icepush</artifactId>
            <version>4.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.icefaces</groupId>
            <artifactId>icefaces-compat</artifactId>
            <version>3.3.0</version>
            <type>pom</type>
        </dependency>

        <dependency>
            <groupId>com.oag.reference</groupId>
            <artifactId>business</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.7</version>
        </dependency>

        <dependency>
            <groupId>org.icefaces.ace-themes</groupId>
            <artifactId>ace-cupertino</artifactId>
            <version>4.0.0</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>

    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.sun.faces</groupId>
                <artifactId>jsf-api</artifactId>
                <version>2.2.7</version>
            </dependency>
            <dependency>
                <groupId>com.sun.faces</groupId>
                <artifactId>jsf-impl</artifactId>
                <version>2.2.7</version>
            </dependency>
        </dependencies>

    </dependencyManagement>

 </project>

Answer 1

这很可能是由于手边有错误的上下文类加载器的错误导致的，该错误在Mojarra2.2.9中已按照问题3341进行了修复。

至少升级到Mojarra 2.2.9（当前最新版本为2.2.12)应该可以解决您的问题。