Custom exception is not working in filter using spring boot and spring security

Question

I am creating rest API with JWT token base security using spring boot and spring security. I want to throw custom exception when token is invalid. So that I have create custom exception class and whenever I throw that exception, I get blank response in postman every time.

I want throw this one

 if (header == null || !header.startsWith("Bearer")) {
    throw new JwtTokenMissingException("No JWT token found in the request headers");
  }

because I am sending token without Bearer keyword. It print in console but not throw in postman.

blank response in postman every time

JwtAuthenticationEntryPoint class

@Component
public class JwtAuthenticationEntryPoint implements AuthenticationEntryPoint, Serializable[!
    private static final long serialVersionUID = 1L;

    @Override
    public void commence(HttpServletRequest request, HttpServletResponse response,
            AuthenticationException authException) throws IOException, ServletException {
        response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Unauthorized");
    }
}

WebSecurityConfig class

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private UserDetailsServiceImpl userDetailsService;

    @Autowired
    private JwtAuthenticationEntryPoint unauthorizedHandler;

    @Override
    @Bean
    public AuthenticationManager authenticationManagerBean() throws Exception {
        return super.authenticationManagerBean();
    }

    @Autowired
    public void globalUserDetails(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService).passwordEncoder(encoder());
    }

    @Bean
    public JwtAuthenticationFilter authenticationTokenFilterBean() throws Exception {
        return new JwtAuthenticationFilter();
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.csrf().disable().authorizeRequests().antMatchers("/login").permitAll().anyRequest()
                .authenticated().and().exceptionHandling().authenticationEntryPoint(unauthorizedHandler).and()
                .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS);
        http.addFilterBefore(authenticationTokenFilterBean(), UsernamePasswordAuthenticationFilter.class);
    }

    @Bean
    public BCryptPasswordEncoder encoder() {
        return new BCryptPasswordEncoder();
    }

}

JwtAuthenticationFilter class

@Component
public class JwtAuthenticationFilter extends OncePerRequestFilter {

    @Autowired
    private UserDetailsService userDetailsService;

    @Autowired
    private JwtTokenUtil jwtTokenUtil;

    @Value("${jwtTokenPrefix}")
    private String tokenPrefix;

    @Override
    protected void doFilterInternal(HttpServletRequest req, HttpServletResponse res, FilterChain chain)
            throws IOException, ServletException {

        String header = req.getHeader("Authorization");
        String username = null;
        String authToken = null;

        if (header == null || !header.startsWith("Bearer")) {
            throw new JwtTokenMissingException("No JWT token found in the request headers");
        }

        authToken = header.replace(tokenPrefix, "");
        jwtTokenUtil.validateJwtToken(authToken);
        username = jwtTokenUtil.getUserNameFromJwtToken(authToken);
        if (username != null && SecurityContextHolder.getContext().getAuthentication() == null) {

            UserDetails userDetails = userDetailsService.loadUserByUsername(username);
            UsernamePasswordAuthenticationToken authentication = new UsernamePasswordAuthenticationToken(userDetails,
                    null, userDetails.getAuthorities());
            authentication.setDetails(new WebAuthenticationDetailsSource().buildDetails(req));
            logger.info("authenticated user " + username + ", setting security context");
            SecurityContextHolder.getContext().setAuthentication(authentication);
        }
        chain.doFilter(req, res);
    }
}

JwtTokenUtil class

@Component
public class JwtTokenUtil implements Serializable {

    private static final long serialVersionUID = 1L;

    @Value("${jwtSecret}")
    private String jwtSecret;

    @Value("${jwtExpirationInMs}")
    private int jwtExpirationMs;

    public String generateJwtToken(String username) {

        return Jwts.builder()
                .setSubject((username))
                .setIssuedAt(new Date())
                .setExpiration(new Date((new Date()).getTime() + jwtExpirationMs))
                .signWith(SignatureAlgorithm.HS512, jwtSecret)
                .compact();
    }

    public String getUserNameFromJwtToken(String token) {
        return Jwts.parser().setSigningKey(jwtSecret).parseClaimsJws(token).getBody().getSubject();
    }

    public void validateJwtToken(String authToken) throws JwtTokenMalformedException, JwtTokenMissingException {
        try {
            Jwts.parser().setSigningKey(jwtSecret).parseClaimsJws(authToken);
        } catch (SignatureException e) {
            throw new JwtTokenMalformedException("Invalid JWT signature");
        } catch (MalformedJwtException e) {
            throw new JwtTokenMalformedException("Invalid JWT token");
        } catch (ExpiredJwtException e) {
            throw new JwtTokenMalformedException("Expired JWT token");
        } catch (UnsupportedJwtException e) {
            throw new JwtTokenMalformedException("Unsupported JWT token");
        } catch (IllegalArgumentException e) {
            throw new JwtTokenMissingException("JWT claims string is empty.");
        }
    }

}

Custom Exception classes

public class JwtTokenMalformedException extends AuthenticationException {
    private static final long serialVersionUID = 1L;

    public JwtTokenMalformedException(String msg) {
        super(msg);
    }
}


public class JwtTokenMissingException extends AuthenticationException {
    private static final long serialVersionUID = 1L;

    public JwtTokenMissingException(String msg) {
        super(msg);
    }
}

Answer 1

Try below code:

String jwtToken = null;

if(headers.containKey("Authorization")){
   jwtToken = headers.get("Authorization");
}

if (jwtToken == null || !jwtToken.startsWith("Bearer")) {
    throw new JwtTokenMissingException("No JWT token found in the request headers");
}