private AvaticaServerConfiguration buildSpnegoConfiguration()

in server/src/main/java/org/apache/calcite/avatica/server/HttpServer.java [908:980]
60 lines of code
3 McCabe index (conditional complexity)

    private AvaticaServerConfiguration buildSpnegoConfiguration(Builder b) {
      final String principal = b.kerberosPrincipal;
      final int separatorIndex = principal.indexOf('/');
      if (separatorIndex < 1) {
        throw new RuntimeException("Expected principal to be of the form primary/instance"
            + " but got " + principal);
      }
      final String primary = principal.substring(0, separatorIndex);
      final int atSignIndex = principal.indexOf('@');
      final String instance;
      // Trim off the @REALM if it's present
      if (atSignIndex == -1) {
        instance = principal.substring(separatorIndex + 1);
      } else {
        instance = principal.substring(separatorIndex + 1, atSignIndex);
      }
      final String realm = b.kerberosRealm;
      final File keytab = b.keytab;
      final String[] additionalAllowedRealms = b.loginServiceAllowedRoles;
      final DoAsRemoteUserCallback callback = b.remoteUserCallback;
      final RemoteUserExtractor remoteUserExtractor = b.remoteUserExtractor;
      return new AvaticaServerConfiguration() {

        @Override public AuthenticationType getAuthenticationType() {
          return AuthenticationType.SPNEGO;
        }

        @Override public String getKerberosRealm() {
          return realm;
        }

        @Override public String getKerberosPrincipal() {
          return principal;
        }

        @Override public String getKerberosServiceName() {
          return primary;
        }

        @Override public String getKerberosHostName() {
          return instance;
        }

        @Override public File getKerberosKeytab() {
          return keytab;
        }

        @Override public boolean supportsImpersonation() {
          return null != callback;
        }

        @Override public <T> T doAsRemoteUser(String remoteUserName, String remoteAddress,
            Callable<T> action) throws Exception {
          return callback.doAsRemoteUser(remoteUserName, remoteAddress, action);
        }

        @Override public RemoteUserExtractor getRemoteUserExtractor() {
          return remoteUserExtractor;
        }

        @Override public String[] getAllowedRoles() {
          return additionalAllowedRealms;
        }

        @Override public String getHashLoginServiceRealm() {
          return null;
        }

        @Override public String getHashLoginServiceProperties() {
          return null;
        }
      };
    }