Error While Installing JSF Facet in Eclipse Project - eclipse

Question

Error While Installing JSF Facet in Eclipse Project
Detailed exception trace from .metadata/.log
!ENTRY org.eclipse.wst.common.project.facet.core 4 0 2018-10-04 18:48:27.943
!MESSAGE Failed while installing JavaServer Faces 2.2.
!STACK 0
java.lang.NullPointerException
at org.eclipse.jst.jsf.core.internal.project.facet.JSFFacetInstallDelegate.resolveConfigPath(JSFFacetInstallDelegate.java:313)
at org.eclipse.jst.jsf.core.internal.project.facet.JSFFacetInstallDelegate.createConfigFile(JSFFacetInstallDelegate.java:331)
at org.eclipse.jst.jsf.core.internal.project.facet.JSFFacetInstallDelegate.execute(JSFFacetInstallDelegate.java:130)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.callDelegate(FacetedProject.java:1477)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.modifyInternal(FacetedProject.java:441)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.mergeChangesInternal(FacetedProject.java:1181)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.access$2(FacetedProject.java:1117)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProject$5.run(FacetedProject.java:1099)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2313)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.mergeChanges(FacetedProject.java:1109)
at org.eclipse.wst.common.project.facet.core.internal.FacetedProjectWorkingCopy.commitChanges(FacetedProjectWorkingCopy.java:2020)
at org.eclipse.wst.common.project.facet.ui.internal.FacetsPropertyPage$4.run(FacetsPropertyPage.java:232)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2313)
at org.eclipse.wst.common.project.facet.ui.internal.FacetsPropertyPage$5.run(FacetsPropertyPage.java:246)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:122)
!SESSION 2018-10-05 10:56:32.004 -----------------------------------------------
eclipse.buildId=3.6.1.201408250818-RELEASE-e44
java.version=1.7.0_51
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_US
Framework arguments: -product org.springsource.sts.ide
Command-line arguments: -os win32 -ws win32 -arch x86 -product org.springsource.sts.ide

Answer 1

Is this project a "Dinamic Web Project"? If so, you have to select a "Dynamic web module version" 2.5 or higher, because JavaServer Faces 2.2 requires this version.
You can also try to delete the project (save to another location first, just to be safe) and import it as a maven project, adding the facets latter or adjusting your pom.xml example:
<dependency>
<groupId>com.sun.faces</groupId>
<artifactId>jsf-api</artifactId>
<version>2.1.13</version>
</dependency>
<dependency>
<groupId>com.sun.faces</groupId>
<artifactId>jsf-impl</artifactId>
<version>2.1.13</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
</dependency>
You can also check your web.xml as picture below.
It should be like the code below, according to your "Dynamic Web Module" (see version 3.1 and web-app_3_1):
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">