How to solve OncePerRequestFilter abstract class Autowired getting null pointer exception?

Question

I am using spring boot(2.2.0.RELEASE) JWT Authentication using OncePerRequestFilter abstract class.While autowired service class is getting null exception.I tried some ways but still getting same.Can any one help me for that issue.

Code :

@Component
    public class JwtRequestFilter extends OncePerRequestFilter {

        @Autowired
        private JwtUserDetailsService jwtUserDetailsService;
        @Autowired
        private JwtTokenUtil jwtTokenUtil;

        @Override
        protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
                throws ServletException, IOException {    
            try {
                final String requestTokenHeader = request.getHeader("Authorization");
                String username = "";
                String jwtToken = "";            
                if (requestTokenHeader != null && requestTokenHeader.startsWith("Bearer ")) {
                    jwtToken = requestTokenHeader.substring(7);
                    try {
                         //here getting null pointer exception
                        username = jwtTokenUtil.getUsernameFromToken(jwtToken);
                        logger.info("username : " + username);
                    } catch (IllegalArgumentException e) {
                        logger.error("Unable to get JWT Token :: " + e.getMessage());                    
                    } catch (ExpiredJwtException e) {
                        logger.error("JWT Token has expired :: " + e.getMessage());                   
                    }
                } else {
                    logger.warn("JWT Token does not begin with Bearer String");
                }
                if (username != null && SecurityContextHolder.getContext().getAuthentication() == null) {
                    UserDetails userDetails = jwtUserDetailsService.loadUserByUsername(username);
                    if (jwtTokenUtil.validateToken(jwtToken, userDetails)) {
                        UsernamePasswordAuthenticationToken usernamePasswordAuthenticationToken = new UsernamePasswordAuthenticationToken(
                                userDetails, null, userDetails.getAuthorities());
                        usernamePasswordAuthenticationToken
                                .setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
                        SecurityContextHolder.getContext().setAuthentication(usernamePasswordAuthenticationToken);
                    }
                }
                chain.doFilter(request, response);
            } catch (Exception e) {
                logger.error("JwtRequestFilter Exception :: " + e.getMessage());            
            }
        }
        }

This below posted code is another class.

 @Service
    @Component
    public class JwtTokenUtil implements Serializable {        
        private static final long serialVersionUID = -2550185165626007488L;                                               
        public String getUsernameFromToken(String token) {
            return getClaimFromToken(token, Claims::getSubject);
        }                       
    }

Exception :

java.lang.NullPointerException
        at com.corenttech.engine.jwt.config.JwtRequestFilter.doFilterInternal(JwtRequestFilter.java:101)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:678)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1579)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:745)

web.xml This is my web.xml i have configured JwtRequestFilter

<web-app>   
    <filter>
        <filter-name>JwtRequestFilter</filter-name>
        <filter-class>com.demo.engine.jwt.config.JwtRequestFilter
        </filter-class>
    </filter>
    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <filter-mapping>
        <filter-name>JwtRequestFilter</filter-name>
        <url-pattern>/kb/*</url-pattern>
    </filter-mapping>       
</web-app>

That service class name is JwtUserDetailsService and JwtTokenUtil @ Stultuske — Ajith Deivam, Feb 11 '20 at 07:09
While call that class methods getting null pointer exception — Ajith Deivam, Feb 11 '20 at 07:10
so, the code that fails is not the code you've shown, but where you try to autowire this code? — Stultuske, Feb 11 '20 at 07:13
I trying to call username = jwtTokenUtil.getUsernameFromToken(jwtToken); this time getiing null — Ajith Deivam, Feb 11 '20 at 07:29
have you debugged your code to see what field is null? how do you instantiate your JwtRequestFilter? — Stultuske, Feb 11 '20 at 07:46
Classes referenced in `web.xml` are instantiated using `new` by the servlet container (or rather using reflection, to be more exact), so auto-wiring doesn't happen. Only class instances created by the container are auto-wired. — Andreas, Feb 11 '20 at 08:55
Which class i need to add in web.xml JwtRequestFilter or JwtUserDetailsService @Andreas — Ajith Deivam, Feb 11 '20 at 09:39
Give exact solution for me ,I m struggling last one week still facing same issue @Andreas — Ajith Deivam, Feb 11 '20 at 09:40
This answer shows what you need to do: https://stackoverflow.com/a/43769987/5221149 — Andreas, Feb 11 '20 at 09:42

How to solve OncePerRequestFilter abstract class Autowired getting null pointer exception?

0 Answers0