Having issue while running a spring boot project using WebLogic

Question

I converted a spring project to a spring boot project and when I try to run the project the index page is coming fine and when I click any link it is going to a error page.

Project version details:

• JDK 11
• Spring Boot 2.6.4
• Gradle 6.8
• WebLogic 14c

Error 500--Internal Server Error
java.lang.NullPointerException
    at weblogic.servlet.internal.ServletResponseImpl.sendContentError(ServletResponseImpl.java:768)
    at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:826)
    at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:743)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.handleErrorStatus(ErrorPageFilter.java:156)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:128)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.access$000(ErrorPageFilter.java:64)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:101)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
    at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:119)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:82)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:82)
    at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:32)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:82)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3866)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3829)
    at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:344)
    at weblogic.security.service.SecurityManager.runAsForUserCode(SecurityManager.java:197)
    at weblogic.servlet.provider.WlsSecurityProvider.runAsForUserCode(WlsSecurityProvider.java:203)
    at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:71)
    at weblogic.servlet.internal.WebAppServletContext.processSecuredExecute(WebAppServletContext.java:2502)
    at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2351)
    at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2326)
    at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2304)
    at weblogic.servlet.internal.ServletRequestImpl.runInternal(ServletRequestImpl.java:1779)
    at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1733)
    at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:272)
    at weblogic.invocation.ComponentInvocationContextManager._runAs(ComponentInvocationContextManager.java:352)
    at weblogic.invocation.ComponentInvocationContextManager.runAs(ComponentInvocationContextManager.java:337)
    at weblogic.work.LivePartitionUtility.doRunWorkUnderContext(LivePartitionUtility.java:57)
    at weblogic.work.PartitionUtility.runWorkUnderContext(PartitionUtility.java:41)
    at weblogic.work.SelfTuningWorkManagerImpl.runWorkUnderContext(SelfTuningWorkManagerImpl.java:651)
    at weblogic.work.ExecuteThread.execute(ExecuteThread.java:420)
    at weblogic.work.ExecuteThread.run(ExecuteThread.java:360)

My weblogic.xml

<?xml version="1.0" encoding="UTF-8"?>
<wls:weblogic-web-app
    xmlns:wls="http://xmlns.oracle.com/weblogic/weblogic-web-app"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd http://xmlns.oracle.com/weblogic/weblogic-web-app http://xmlns.oracle.com/weblogic/weblogic-web-app/1.7/weblogic-web-app.xsd">
    <wls:weblogic-version>12.1.3</wls:weblogic-version>
    <wls:context-root>insightstats</wls:context-root>
    <wls:container-descriptor>
        <wls:prefer-application-packages>
            <wls:package-name>class org.slf4j.impl.JDK14LoggerFactory</wls:package-name>
            <wls:package-name>org.springframework.*</wls:package-name>
        </wls:prefer-application-packages>
    </wls:container-descriptor>
    <wls:session-descriptor>
        <wls:cookie-secure>true</wls:cookie-secure>
        <wls:http-proxy-caching-of-cookies>false</wls:http-proxy-caching-of-cookies>
    </wls:session-descriptor>
</wls:weblogic-web-app>

My web.xml

<web-app xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
     version="3.0">

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

</web-app>

tried different configurations and added needed dependencies and other project with same configuration is working fine.

Note:

• So this is happening only when the controller is having the request mapping like @RequestMapping(value = { "/dummy" })

• But upon clicking a link the url directly forms like http://localhost:7001/dummy.html this error is showing up

• I tried manually changing like http://localhost:7001/dummy then the page is working fine.

• And when the request mapping is like @RequestMapping(value = { "/dummy.html" }) the pages are loading fine and the links in the opened page are also redirecting fine

• Is it suggested to put .html in Request mapping mapping or what changes do I need to make to make it work fine without .html