Java 类org.springframework.security.authentication.ProviderManager 实例源码

/**
 * authenticates a second user while the main user is already authenticated. The authentication information for the
 * second user are not stored in the security context but in Cibet context. A second authentication is necessary for
 * the Two-man-rule actuator.
 * 
 * @param auth
 *           Credentials of the second user
 * @throws AuthenticationException
 *            in case of error
 */
public void logonSecondUser(Authentication auth) throws AuthenticationException {
   try {
      AuthenticationManager authManager = context.getBean(ProviderManager.class);
      Authentication result = authManager.authenticate(auth);
      Context.internalSessionScope().setSecondUser(result.getName());
      Context.internalSessionScope().setProperty(InternalSessionScope.SECOND_PRINCIPAL, result);
      if (log.isDebugEnabled()) {
         log.debug("User " + result.getName() + " is successfully authenticated");
      }
   } catch (NoSuchBeanDefinitionException e1) {
      String msg = "Failed to authenticate second user: "
            + "Failed to find a ProviderManager bean in Spring context. Configure Spring context correctly: "
            + e1.getMessage();
      log.error(msg);
      throw new RuntimeException(msg, e1);
   }
}

private void runUserSynchronizerJob() {
    if (LOG.isDebugEnabled()) {
        LOG.debug("Run user synchronizer job ...");
    }
    long t = System.currentTimeMillis();

    // JobDetail userSynchronizerJob = (JobDetail)
    // getSpringBean("userSynchronizerJob");
    ProviderManager authenticationManager = (ProviderManager) getSpringBean("authenticationManager");
    UserSynchronizerJob userSynchronizerJob = new UserSynchronizerJob();
    userSynchronizerJob.setAuthenticationManager(authenticationManager);
    userSynchronizerJob.setStorageService((StorageService) getSpringBean("storageService"));
    userSynchronizerJob.syncUsers();

    if (LOG.isDebugEnabled()) {
        t = System.currentTimeMillis() - t;
        LOG.debug("Users synchronized in " + t + " ms");
    }
}

@Bean("authenticationManager")
public ProviderManager authenticationManager() {
    List<AuthenticationProvider> authProviderList = new ArrayList<AuthenticationProvider>();
    authProviderList.add(authProvider());
    ProviderManager providerManager = new ProviderManager(authProviderList);
    return providerManager;
}

@Bean
public AuthenticationManager clientAuthenticationManager() {
    DaoAuthenticationProvider clientAuthenticationProvider = new DaoAuthenticationProvider();
    clientAuthenticationProvider.setUserDetailsService(clientDetailsUserDetailsService());
    clientAuthenticationProvider.setHideUserNotFoundExceptions(false);
    return new ProviderManager(Collections.singletonList(clientAuthenticationProvider));
}

private UserDetails getUser() {
    ProviderManager parent = (ProviderManager) this.context
            .getBean(AuthenticationManager.class);
    DaoAuthenticationProvider provider = (DaoAuthenticationProvider) parent
            .getProviders().get(0);
    UserDetailsService service = (UserDetailsService) ReflectionTestUtils
            .getField(provider, "userDetailsService");
    UserDetails user = service.loadUserByUsername("user");
    return user;
}

/**
 * @param identifier
 *            Identifier of the provider to use. if <code>null</code> the next possible provider
 *            will be used.
 * @return Get the provider, which is able to handle an invitation.
 */
public BaseCommunoteAuthenticationProvider getInvitationProvider(String identifier) {
    ProviderManager authenticationManager = getProviderManager();

    // all providers to iterate for
    List<AuthenticationProvider> providers = new ArrayList<AuthenticationProvider>(
            authenticationManager.getProviders());
    // also add the plugin providers
    // TODO far from perfect, it would be better to have them all in single list, but this means
    // moving the authentication provider stuff into the core
    List<CommunoteAuthenticationProvider> pluginProviders = ServiceLocator.instance()
            .getService(AuthenticationProviderManagement.class).getProviders();
    providers.addAll(pluginProviders);

    for (Object object : providers) {
        if (!(object instanceof BaseCommunoteAuthenticationProvider)) {
            continue;
        }
        BaseCommunoteAuthenticationProvider provider = (BaseCommunoteAuthenticationProvider) object;
        if (provider.supportsUserQuerying()
                && (identifier == null || provider.getIdentifier().equals(identifier))) {
            return provider;
        }
    }
    throw new IllegalStateException("There is no provider that allows an invitation!");

}

/**
 * Iterates over the internal list of authentication providers an tries to authenticate.
 * 
 * @param authentication
 *            The authentication.
 * @return The resulting authentication.
 */
public Authentication authenticate(Authentication authentication) {
    ProviderManager providerManager = getManager();
    if (providerManager != null) {
        try {
            return providerManager.authenticate(authentication);
        } catch (ProviderNotFoundException e) {
            // will be thrown if there is no supporting provider, ignore it since we are not
            // calling supports methods of the registered providers
        }
    }
    return null;
}

/**
 * @return the lazily initialized manager or null if no providers are registered
 */
private ProviderManager getManager() {
    if (manager == null && !providers.isEmpty()) {
        initProviderManager();
    }
    return manager;
}

/**
 * @param alias
 *            the alias
 * @param password
 *            the password
 * @param email
 *            the email
 * @throws Exception
 *             in case of an error
 */
@BeforeClass(dependsOnGroups = "integration-test-setup")
public void init() throws Exception {
    UserVO userVO = TestUtils.createKenmeiUserVO(TestUtils.createRandomUserAlias(),
            UserRole.ROLE_KENMEI_USER);
    userVO.setPassword("123456");
    AuthenticationTestUtils.setManagerContext();
    userManagement.createUser(userVO, false, false);
    Map<ClientConfigurationPropertyConstant, String> map;
    map = new HashMap<ClientConfigurationPropertyConstant, String>();
    // set lower limit for getting permanently locked (to speed up test)
    map.put(ClientPropertySecurity.FAILED_AUTH_LIMIT_PERMLOCK, String.valueOf(6));
    // set shorter wait time for temporarily locked users
    map.put(ClientPropertySecurity.FAILED_AUTH_LOCKED_TIMESPAN, String.valueOf(3));
    CommunoteRuntime.getInstance().getConfigurationManager()
            .updateClientConfigurationProperties(map);
    AuthenticationTestUtils.setAuthentication(null);
    // initiate authenticationManager
    ArrayList<AuthenticationProvider> providers = new ArrayList<>();
    providers.add(new DatabaseAuthenticationProvider());
    ProviderManager providerManager = new ProviderManager(providers);
    providerManager.setAuthenticationEventPublisher(new AuthenticationFailedEventPublisher());
    authManager = providerManager;
    // create valid user + password-token
    validAuth = new UsernamePasswordAuthenticationToken(userVO.getAlias(),
            userVO.getPassword());
    // create invalid user + password-token
    invalidAuth = new UsernamePasswordAuthenticationToken(userVO.getAlias(),
            userVO.getPassword() + "invalid");
}

@Override
public void configure(HttpSecurity http) throws Exception {
    PreAuthenticatedAuthenticationProvider casAuthenticationProvider = new PreAuthenticatedAuthenticationProvider();
    casAuthenticationProvider.setPreAuthenticatedUserDetailsService(
            new UserDetailsByNameServiceWrapper<>(peticionamentoUserDetailService.orElseThrow(() ->
                            SingularServerException.rethrow(
                                    String.format("Bean %s do tipo %s não pode ser nulo. Para utilizar a configuração de segurança %s é preciso declarar um bean do tipo %s identificado pelo nome %s .",
                                            UserDetailsService.class.getName(),
                                            "peticionamentoUserDetailService",
                                            SingularCASSpringSecurityConfig.class.getName(),
                                            UserDetailsService.class.getName(),
                                            "peticionamentoUserDetailService"
                                    ))
            )
            )
    );

    ProviderManager authenticationManager = new ProviderManager(Arrays.asList(new AuthenticationProvider[]{casAuthenticationProvider}));

    J2eePreAuthenticatedProcessingFilter j2eeFilter = new J2eePreAuthenticatedProcessingFilter();
    j2eeFilter.setAuthenticationManager(authenticationManager);

    http
            .regexMatcher(getContext().getPathRegex())
            .httpBasic().authenticationEntryPoint(new Http403ForbiddenEntryPoint())
            .and()
            .csrf().disable()
            .headers().frameOptions().sameOrigin()
            .and()
            .jee().j2eePreAuthenticatedProcessingFilter(j2eeFilter)
            .and()
            .authorizeRequests()
            .antMatchers(getContext().getContextPath()).authenticated();

}

private UserDetails getUser() {
    ProviderManager parent = (ProviderManager) this.context
            .getBean(AuthenticationManager.class);
    DaoAuthenticationProvider provider = (DaoAuthenticationProvider) parent
            .getProviders().get(0);
    UserDetailsService service = (UserDetailsService) ReflectionTestUtils
            .getField(provider, "userDetailsService");
    UserDetails user = service.loadUserByUsername("user");
    return user;
}

@Bean
  @SuppressWarnings({ "rawtypes", "unchecked" })
  public AuthenticationManager authenticationManager(){

      if (authenticationManager == null){
List providers = new ArrayList();
      providers.add(daoAuthenticationProvider());
      providers.add(new AnonymousAuthenticationProvider("changeThis"));
      providers.add(new RememberMeAuthenticationProvider("changeThis"));

      ProviderManager bean = new ProviderManager(providers);
      authenticationManager = bean;
      }
      return authenticationManager;
  }

@Bean
public AuthenticationManager authenticationManager(UserDetailsService userDetailsService,
        RunAsImplAuthenticationProvider runAsProvider, PasswordEncoder passwordEncoder) {
    List<AuthenticationProvider> providers = Lists.newArrayList();
    providers.add(runAsProvider);
    DaoAuthenticationProvider authenticationProvider = new DaoAuthenticationProvider();
    authenticationProvider.setUserDetailsService(userDetailsService);
    authenticationProvider.setPasswordEncoder(passwordEncoder);
    providers.add(authenticationProvider);
    return new ProviderManager(providers);
}

private UserDetails getUser() {
    ProviderManager parent = (ProviderManager) this.context
            .getBean(AuthenticationManager.class);
    DaoAuthenticationProvider provider = (DaoAuthenticationProvider) parent
            .getProviders().get(0);
    UserDetailsService service = (UserDetailsService) ReflectionTestUtils
            .getField(provider, "userDetailsService");
    UserDetails user = service.loadUserByUsername("user");
    return user;
}

@Bean
@Override
public AuthenticationManager authenticationManager()
{
    PreAuthenticatedAuthenticationProvider authenticationProvider = new PreAuthenticatedAuthenticationProvider();
    authenticationProvider.setPreAuthenticatedUserDetailsService(herdUserDetailsService);
    List<AuthenticationProvider> providers = new ArrayList<>();
    providers.add(authenticationProvider);
    return new ProviderManager(providers);
}

public void refreshContext(boolean ssoMode, String entityId) {
    LOG.info("Context refresh process started. SSO mode: {}", ssoMode);
    CONTEXT_REFRESH_IN_PROCESS = true;
    //for sso
    if(ssoMode) {
        // do not change order of context refreshes
        // we need to refresh root context otherwise springSecurityFilterChain will not be updated
        // https://jira.spring.io/browse/SPR-6228
        XmlWebApplicationContext rootContext = (XmlWebApplicationContext) applicationContext.getParent();
        rootContext.setConfigLocations("/WEB-INF/spring-security-saml.xml");
        // add property entityId to root context, it will be used as psw for jks
        rootContext.getEnvironment().getPropertySources().addLast((new RefreshRootContextPropertySource(entityId)));
        rootContext.refresh();

        // refresh application context
        applicationContext.setConfigLocations("/WEB-INF/spring-web-config.xml");
        applicationContext.refresh();

        // set userService property to userDetails bean, so we could manage users roles within ssoLogin mode
        applicationContext.getBean(SamlUserDetails.class).setUserService(applicationContext.getBean(UserService.class));
        applicationContext.getBean(SAMLAuthenticationProviderImpl.class).setConfigurationMediator(applicationContext.getBean(ConfigurationMediator.class));
        applicationContext.getBean(SAMLAuthenticationProviderImpl.class).setUserService(applicationContext.getBean(UserService.class));
    }
    // for local authentication
    else {
        applicationContext.setConfigLocations("/WEB-INF/spring-web-config.xml", "/WEB-INF/spring-security-dynamoDB.xml");
        applicationContext.refresh();
        // clearing init auth providers
        ((ProviderManager)applicationContext.getBean("authenticationManager")).getProviders().clear();

        // adding main auth provider
        ((ProviderManager)applicationContext.getBean("authenticationManager")).getProviders()
                .add((AuthenticationProvider) applicationContext.getBean("authProvider"));
    }

    LOG.info("Context refreshed successfully.");
    SecurityContextHolder.clearContext();
    CONTEXT_REFRESH_IN_PROCESS = false;
}

/**
 * Gets the provider manager.
 *
 * @return the provider manager
 */
@Bean(name = "authenticationManager")
public ProviderManager getProviderManager() {
  List<AuthenticationProvider> providers = new ArrayList<>();
  providers.add(getPreAuthenticatedAuthenticationProvider());
  return new ProviderManager(providers);
}

/**
 * @throws Exception
 */
@Test
public final void testLogin() throws Exception {
    Authentication auth = new UsernamePasswordAuthenticationToken( username, pwd );

    Authentication authentication = ( ( ProviderManager ) authenticationManager ).authenticate( auth );
    assertTrue( authentication.isAuthenticated() );
}

@Test
public final void testLoginNonexistentUser() throws Exception {
    Authentication auth = new UsernamePasswordAuthenticationToken( "bad user", "wrong password" );

    try {
        ( ( ProviderManager ) authenticationManager ).authenticate( auth );
        fail( "Should have gotten a bad credentials exception" );
    } catch ( BadCredentialsException e ) {
        //
    }
}

@Test
public final void testLoginWrongPassword() throws Exception {
    Authentication auth = new UsernamePasswordAuthenticationToken( username, "wrong password" );

    try {
        ( ( ProviderManager ) authenticationManager ).authenticate( auth );
        fail( "Should have gotten a bad credentials exception" );
    } catch ( BadCredentialsException e ) {
        //
    }
}

/**
 * Grant authority to a test user, with admin privileges, and put the token in the context. This means your tests
 * will be authorized to do anything an administrator would be able to do.
 */
protected void grantAdminAuthority( ApplicationContext ctx ) {
    ProviderManager providerManager = ( ProviderManager ) ctx.getBean( "authenticationManager" );
    providerManager.getProviders().add( new TestingAuthenticationProvider() );

    // Grant all roles to test user.
    TestingAuthenticationToken token = new TestingAuthenticationToken( "administrator", "administrator",
            Arrays.asList( new GrantedAuthority[] { new SimpleGrantedAuthority(
                    AuthorityConstants.ADMIN_GROUP_AUTHORITY ) } ) );

    token.setAuthenticated( true );

    putTokenInContext( token );
}

protected void grantAnonAuthority( ApplicationContext ctx ) {
    ProviderManager providerManager = ( ProviderManager ) ctx.getBean( "authenticationManager" );
    providerManager.getProviders().add( new TestingAuthenticationProvider() );

    // Grant all roles to test user.
    TestingAuthenticationToken token = new TestingAuthenticationToken( "anon", "anon",
            Arrays.asList( new GrantedAuthority[] { new SimpleGrantedAuthority(
                    AuthorityConstants.IS_AUTHENTICATED_ANONYMOUSLY ) } ) );

    token.setAuthenticated( true );

    putTokenInContext( token );
}

@Bean(name = "preAuthAuthenticationManager")
public AuthenticationManager preAuthAuthenticationManager() {
    PreAuthenticatedAuthenticationProvider preAuthProvider = new PreAuthenticatedAuthenticationProvider();
    preAuthProvider.setPreAuthenticatedUserDetailsService(preAuthUserDetailsService);

    List<AuthenticationProvider> providers = new ArrayList<AuthenticationProvider>();
    providers.add(preAuthProvider);

    return new ProviderManager(providers);
}

@Bean(name = "preAuthAuthenticationManager")
public AuthenticationManager preAuthAuthenticationManager() {
    PreAuthenticatedAuthenticationProvider preAuthProvider = new PreAuthenticatedAuthenticationProvider();
    preAuthProvider.setPreAuthenticatedUserDetailsService(preAuthUserDetailsService());

    return new ProviderManager(Arrays.asList(preAuthProvider));
}

@Override
protected AuthenticationManager authenticationManager() throws Exception {
     return new ProviderManager(Arrays.asList(appAdminProvider, appHRProvider ), appAuthenticationMgr);
}

@Override
protected AuthenticationManager authenticationManager() throws Exception {
 return new ProviderManager(Arrays.asList(appAdminProvider, appHRProvider ), appAuthenticationMgr);
}

@Override
protected AuthenticationManager authenticationManager() throws Exception {
     return new ProviderManager(Arrays.asList(appAdminProvider, appHRProvider ), appAuthenticationMgr);
}

@Override
protected AuthenticationManager authenticationManager() throws Exception {
 return new ProviderManager(Arrays.asList(appAdminProvider, appHRProvider ), appAuthenticationMgr);
}

@Bean
@Override
public AuthenticationManager authenticationManager() throws Exception {
    return new ProviderManager(Arrays.asList(authenticationProvider));
}

@Bean
public AuthenticationManager authenticationManager() {
    return new ProviderManager(Arrays.asList(clientAuthenticationProvider(), userAuthenticationProvider()));
}

@Bean
public AuthenticationManager authenticationManager() {
    return new ProviderManager(Arrays.asList(new DaoAuthenticationProvider()));
}

private void configureAuthenticationManager(AuthenticationManager manager) {
    if (manager instanceof ProviderManager) {
        ((ProviderManager) manager)
                .setAuthenticationEventPublisher(this.eventPublisher);
    }
}

/**
 * @return the configured provider manager
 */
public ProviderManager getProviderManager() {
    ProviderManager authenticationManager = (ProviderManager) webApplicationContext
            .getBean("authenticationManager");
    return authenticationManager;
}

/**
 * Tests the correct ordering.
 */
@Test
public void testCorrectOrder() {
    AuthenticationProviderManagement providerManagement = new AuthenticationProviderManagement();
    List<AuthenticationProvider> providers = new ArrayList<AuthenticationProvider>();
    StringBuilder stringToBuild = new StringBuilder();
    providers.add(new TestAuthenticationProvider(0, "A", stringToBuild, false));
    PluginAuthenticationProvider pluginAuthenticationProvider = new PluginAuthenticationProvider();
    pluginAuthenticationProvider.setAuthenticationProviderManagement(providerManagement);
    providers.add(pluginAuthenticationProvider);
    providers.add(new TestAuthenticationProvider(0, "E", stringToBuild, true));

    // Plugin providers.
    CommunoteAuthenticationProvider lowPriorityProvider =
            new TestAuthenticationProvider(0, "B", stringToBuild, true);
    CommunoteAuthenticationProvider midPriorityProvider =
            new TestAuthenticationProvider(500, "C", stringToBuild, true);

    CommunoteAuthenticationProvider noProvider =
            new TestAuthenticationProvider(1000, "Z", stringToBuild, false);

    ProviderManager providerManager = new ProviderManager(providers);
    // Test without filters
    providerManager.authenticate(new TestingAuthenticationToken(null, null));
    Assert.assertEquals(stringToBuild.toString(), "E");

    // Test with 1 additional filter
    stringToBuild.delete(0, 10);
    providerManagement.addAuthenticationProvider(lowPriorityProvider);
    providerManager.authenticate(new TestingAuthenticationToken(null, null));
    Assert.assertEquals(stringToBuild.toString(), "B");

    // Test with 2 additional filter (higher priority wins)
    stringToBuild.delete(0, 10);
    providerManagement.addAuthenticationProvider(midPriorityProvider);
    providerManager.authenticate(new TestingAuthenticationToken(null, null));
    Assert.assertEquals(stringToBuild.toString(), "C");

    // Test with 3 additional filter
    stringToBuild.delete(0, 10);
    providerManagement.addAuthenticationProvider(noProvider);
    providerManager.authenticate(new TestingAuthenticationToken(null, null));
    Assert.assertEquals(stringToBuild.toString(), "C");

    // Test with 2 additional filter
    stringToBuild.delete(0, 10);
    providerManagement.removeCommunoteAuthenticationProvider(midPriorityProvider);
    providerManager.authenticate(new TestingAuthenticationToken(null, null));
    Assert.assertEquals(stringToBuild.toString(), "B");
}

@Bean
@Override
public AuthenticationManager authenticationManager() throws Exception {
    return new ProviderManager(Arrays.asList(provider));
}

private void configureAuthenticationManager(AuthenticationManager manager) {
    if (manager instanceof ProviderManager) {
        ((ProviderManager) manager)
                .setAuthenticationEventPublisher(this.eventPublisher);
    }
}

@Bean
public AuthenticationManager authenticationManager() {
    return new ProviderManager(Collections.singletonList(samlAuthenticationProvider()));
}

private void configureAuthenticationManager(AuthenticationManager manager) {
    if (manager instanceof ProviderManager) {
        ((ProviderManager) manager)
                .setAuthenticationEventPublisher(this.eventPublisher);
    }
}

@SuppressWarnings( { "unchecked" })
   public void contextInitialized(ServletContextEvent event) {
log.debug("initializing context...");

ServletContext context = event.getServletContext();

// Orion starts Servlets before Listeners, so check if the config
// object already exists
Map<String, Object> config = (HashMap<String, Object>) context
    .getAttribute(Constants.CONFIG);

if (config == null) {
    config = new HashMap<String, Object>();
}

if (context.getInitParameter(Constants.CSS_THEME) != null) {
    config.put(Constants.CSS_THEME, context
        .getInitParameter(Constants.CSS_THEME));
}

ApplicationContext ctx = WebApplicationContextUtils
    .getRequiredWebApplicationContext(context);

boolean encryptPassword = true;

   try {
       ProviderManager provider = (ProviderManager) ctx.getBean(ctx.getBeanNamesForType(ProviderManager.class)[0]);
       for (Object o : provider.getProviders()) {
           AuthenticationProvider p = (AuthenticationProvider) o;
           if (p instanceof RememberMeAuthenticationProvider) {
               config.put("rememberMeEnabled", Boolean.TRUE);
           } 
           config.put(Constants.ENCRYPT_PASSWORD, Boolean.TRUE);
           config.put(Constants.ENC_ALGORITHM, "SHA");
       }
   } catch (NoSuchBeanDefinitionException n) {
       log.debug("authenticationManager bean not found, assuming test and ignoring...");
       // ignore, should only happen when testing
   }


context.setAttribute(Constants.CONFIG, config);

// output the retrieved values for the Init and Context Parameters
if (log.isDebugEnabled()) {
    log
        .debug("Remember Me Enabled? "
            + config.get("rememberMeEnabled"));
    log.debug("Encrypt Passwords? " + encryptPassword);
    if (encryptPassword) {
    log.debug("Encryption Algorithm: "
        + config.get(Constants.ENC_ALGORITHM));
    }
    log.debug("Populating drop-downs...");
}

setupContext(context);
   }

/**
 * {@inheritDoc}
 */
@SuppressWarnings("unchecked")
public void contextInitialized(ServletContextEvent event) {
    log.debug("Initializing context...");

    ServletContext context = event.getServletContext();

    // Orion starts Servlets before Listeners, so check if the config
    // object already exists
    Map<String, Object> config = (HashMap<String, Object>) context.getAttribute(Constants.CONFIG);

    if (config == null) {
        config = new HashMap<String, Object>();
    }

    ApplicationContext ctx =
            WebApplicationContextUtils.getRequiredWebApplicationContext(context);

    PasswordEncoder passwordEncoder = null;
    try {
        ProviderManager provider = (ProviderManager) ctx.getBean("org.springframework.security.authentication.ProviderManager#0");
        for (Object o : provider.getProviders()) {
            AuthenticationProvider p = (AuthenticationProvider) o;
            if (p instanceof RememberMeAuthenticationProvider) {
                config.put("rememberMeEnabled", Boolean.TRUE);
            } else if (ctx.getBean("passwordEncoder") != null) {
                passwordEncoder = (PasswordEncoder) ctx.getBean("passwordEncoder");
            }
        }
    } catch (NoSuchBeanDefinitionException n) {
        log.debug("authenticationManager bean not found, assuming test and ignoring...");
        // ignore, should only happen when testing
    }

    context.setAttribute(Constants.CONFIG, config);

    // output the retrieved values for the Init and Context Parameters
    if (log.isDebugEnabled()) {
        log.debug("Remember Me Enabled? " + config.get("rememberMeEnabled"));
        if (passwordEncoder != null) {
            log.debug("Password Encoder: " + passwordEncoder.getClass().getSimpleName());
        }
        log.debug("Populating drop-downs...");
    }

    setupContext(context);

    // Determine version number for CSS and JS Assets
    String appVersion = null;
    try {
        InputStream is = context.getResourceAsStream("/META-INF/MANIFEST.MF");
        if (is == null) {
            log.warn("META-INF/MANIFEST.MF not found.");
        } else {
            Manifest mf = new Manifest();
            mf.read(is);
            Attributes atts = mf.getMainAttributes();
            appVersion = atts.getValue("Implementation-Version");
        }
    } catch (IOException e) {
        log.error("I/O Exception reading manifest: " + e.getMessage());
    }

    // If there was a build number defined in the war, then use it for
    // the cache buster. Otherwise, assume we are in development mode
    // and use a random cache buster so developers don't have to clear
    // their browser cache.
    if (appVersion == null || appVersion.contains("SNAPSHOT")) {
        appVersion = "" + new Random().nextInt(100000);
    }

    log.info("Application version set to: " + appVersion);
    context.setAttribute(Constants.ASSETS_VERSION, appVersion);
}