How to use

ThemeResolver

in

org.springframework.web.servlet

/**
 * Retrieves the current theme from the given request, using the ThemeResolver
 * and ThemeSource bound to the request by the DispatcherServlet.
 * @param request current HTTP request
 * @return the current theme, or {@code null} if not found
 * @see #getThemeResolver
 */
@Nullable
public static Theme getTheme(HttpServletRequest request) {
  ThemeResolver themeResolver = getThemeResolver(request);
  ThemeSource themeSource = getThemeSource(request);
  if (themeResolver != null && themeSource != null) {
    String themeName = themeResolver.resolveThemeName(request);
    return themeSource.getTheme(themeName);
  }
  else {
    return null;
  }
}

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
    throws ServletException {
  String newTheme = request.getParameter(this.paramName);
  if (newTheme != null) {
    ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(request);
    if (themeResolver == null) {
      throw new IllegalStateException("No ThemeResolver found: not in a DispatcherServlet request?");
    }
    themeResolver.setThemeName(request, response, newTheme);
  }
  // Proceed in any case.
  return true;
}

private void internalTest(ThemeResolver themeResolver, boolean shouldSet, String defaultName) {
  // create mocks
  MockServletContext context = new MockServletContext();
  MockHttpServletRequest request = new MockHttpServletRequest(context);
  MockHttpServletResponse response = new MockHttpServletResponse();
  // check original theme
  String themeName = themeResolver.resolveThemeName(request);
  assertEquals(themeName, defaultName);
  // set new theme name
  try {
    themeResolver.setThemeName(request, response, TEST_THEME_NAME);
    if (!shouldSet)
      fail("should not be able to set Theme name");
    // check new theme namelocale
    themeName = themeResolver.resolveThemeName(request);
    assertEquals(TEST_THEME_NAME, themeName);
    themeResolver.setThemeName(request, response, null);
    themeName = themeResolver.resolveThemeName(request);
    assertEquals(themeName, defaultName);
  }
  catch (UnsupportedOperationException ex) {
    if (shouldSet)
      fail("should be able to set Theme name");
  }
}

@Override
public void postHandle(HttpServletRequest request,
    HttpServletResponse response, Object handler,
    ModelAndView modelAndView) throws Exception {
  Locale locale = localeResolver.resolveLocale(request);
  userSettingsHolder.setLocale(locale);
  localeResolver.setLocale(request, response, locale);
  String themeName = themeResolver.resolveThemeName(request);
  userSettingsHolder.setTheme(themeName);
  themeResolver.setThemeName(request, response, themeName);
  final String timezone = timezoneResolver.resolveSetting(request);
  userSettingsHolder.setTimezone(timezone);
  timezoneResolver.setSetting(timezone);
}

/**
 * Retrieves the current theme from the given request, using the ThemeResolver
 * and ThemeSource bound to the request by the DispatcherServlet.
 * @param request current HTTP request
 * @return the current theme, or {@code null} if not found
 * @see #getThemeResolver
 */
@Nullable
public static Theme getTheme(HttpServletRequest request) {
  ThemeResolver themeResolver = getThemeResolver(request);
  ThemeSource themeSource = getThemeSource(request);
  if (themeResolver != null && themeSource != null) {
    String themeName = themeResolver.resolveThemeName(request);
    return themeSource.getTheme(themeName);
  }
  else {
    return null;
  }
}

/**
 * Change the current theme to the specified theme by name,
 * storing the new theme name through the configured {@link ThemeResolver}.
 * @param themeName the name of the new theme
 * @see ThemeResolver#setThemeName
 */
public void changeTheme(String themeName) {
  ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(this.request);
  if (themeResolver == null) {
    throw new IllegalStateException("Cannot change theme if no ThemeResolver configured");
  }
  themeResolver.setThemeName(this.request, this.response, themeName);
  // Ask for re-resolution on next getTheme call.
  this.theme = null;
}

  throw new ServletException("Incorrect ThemeResolver");
if (!"theme".equals(RequestContextUtils.getThemeResolver(request).resolveThemeName(request))) {
  throw new ServletException("Incorrect theme name");
  throw new ServletException("Incorrect TimeZone");
if (!"theme2".equals(RequestContextUtils.getThemeResolver(request).resolveThemeName(request))) {
  throw new ServletException("Incorrect theme name");

/**
 * Change the current theme to the specified one,
 * storing the new theme name through the configured {@link ThemeResolver}.
 * @param theme the new theme
 * @see ThemeResolver#setThemeName
 */
public void changeTheme(@Nullable Theme theme) {
  ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(this.request);
  if (themeResolver == null) {
    throw new IllegalStateException("Cannot change theme if no ThemeResolver configured");
  }
  themeResolver.setThemeName(this.request, this.response, (theme != null ? theme.getName() : null));
  this.theme = theme;
}

@Override
public String resolve(String staticPrefix) {
  String themeName = themeResolver.resolveThemeName(getRequest());
  String path = new File(staticPrefix, themeName).getPath();
  if (staticPrefix.endsWith(File.separator)) {
    return path + File.separator;
  } else {
    return path;
  }
}

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
    throws ServletException {
  String newTheme = request.getParameter(this.paramName);
  if (newTheme != null) {
    ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(request);
    if (themeResolver == null) {
      throw new IllegalStateException("No ThemeResolver found: not in a DispatcherServlet request?");
    }
    themeResolver.setThemeName(request, response, newTheme);
  }
  // Proceed in any case.
  return true;
}

@Override
public String resolveThemeName(HttpServletRequest request) {
  String themeName = getThemeName(request);
  Iterator<ThemeResolver> iter = themeResolvers.iterator();
  
  while (iter.hasNext() && !StringUtils.hasText(themeName)) {
    themeName = iter.next().resolveThemeName(request);
  }
  
  cacheThemeName(request, themeName);
  return StringUtils.hasText(themeName) ? themeName : defaultTheme;
}

/**
 * Change the current theme to the specified theme by name,
 * storing the new theme name through the configured {@link ThemeResolver}.
 * @param themeName the name of the new theme
 * @see ThemeResolver#setThemeName
 */
public void changeTheme(String themeName) {
  ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(this.request);
  if (themeResolver == null) {
    throw new IllegalStateException("Cannot change theme if no ThemeResolver configured");
  }
  themeResolver.setThemeName(this.request, this.response, themeName);
  // Ask for re-resolution on next getTheme call.
  this.theme = null;
}

@Override
public String resolveThemeName(final HttpServletRequest httpServletRequest) {
  val it = chain.iterator();
  while (it.hasNext()) {
    val r = it.next();
    LOGGER.trace("Attempting to resolve theme via [{}]", r.getClass().getSimpleName());
    val resolverTheme = r.resolveThemeName(httpServletRequest);
    if (!resolverTheme.equalsIgnoreCase(getDefaultThemeName())) {
      LOGGER.trace("Resolved theme [{}]", resolverTheme);
      return resolverTheme;
    }
  }
  LOGGER.trace("No specific theme could be found. Using default theme [{}}", getDefaultThemeName());
  return getDefaultThemeName();
}

/**
 * Change the current theme to the specified one,
 * storing the new theme name through the configured {@link ThemeResolver}.
 * @param theme the new theme
 * @see ThemeResolver#setThemeName
 */
public void changeTheme(@Nullable Theme theme) {
  ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(this.request);
  if (themeResolver == null) {
    throw new IllegalStateException("Cannot change theme if no ThemeResolver configured");
  }
  themeResolver.setThemeName(this.request, this.response, (theme != null ? theme.getName() : null));
  this.theme = theme;
}

@ModelAttribute("currentTheme")
public Theme currentTheme(HttpServletRequest request) {
 return themeRegistry.getPluginFor(themeResolver.resolveThemeName(request), themeRegistry.getPluginFor(DEFAULT_THEME_NAME));
}

@Override
public void setThemeName(HttpServletRequest request, HttpServletResponse response, String themeName) {
  themeName = StringUtils.hasText(themeName) ? themeName : defaultTheme;
  
  for (ThemeResolver themeResolver : themeResolvers) {
    themeResolver.setThemeName(request, response, themeName);
  }
}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
ServletException {
  HttpServletRequest httpRequest = (HttpServletRequest) request;
  String themeName = themeResolver.resolveThemeName(httpRequest);
  Theme theme = ThemeRegistry.getInstance().get(themeName);
  if (theme != null) {
    String originalPath = httpRequest.getPathInfo();
    String requestPath = originalPath == null ? null : theme.translatePath(originalPath);
    if (requestPath != null) {
      requestPath = requestPath.isEmpty() ? "empty/" + originalPath : requestPath;
      httpRequest.getRequestDispatcher(requestPath).forward(httpRequest, response);
      return;
    }
  }
  chain.doFilter(request, response);
}

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
    throws ServletException {
  String newTheme = request.getParameter(this.paramName);
  if (newTheme != null) {
    ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(request);
    if (themeResolver == null) {
      throw new IllegalStateException("No ThemeResolver found: not in a DispatcherServlet request?");
    }
    themeResolver.setThemeName(request, response, newTheme);
  }
  // Proceed in any case.
  return true;
}

  private ResourceUrlResolver urlResolver() {
    if (themeResolver == null || !useThemeInViewPath) {
      return IdentityUrlResolver.INSTANCE;
    } else {
      return new ThemedResourceUrlResolver(themeResolver.resolveThemeName(getServletRequest()));
    }
  }
}

/**
 * Change the current theme to the specified one,
 * storing the new theme name through the configured {@link ThemeResolver}.
 * @param theme the new theme
 * @see ThemeResolver#setThemeName
 */
public void changeTheme(Theme theme) {
  ThemeResolver themeResolver = RequestContextUtils.getThemeResolver(this.request);
  if (themeResolver == null) {
    throw new IllegalStateException("Cannot change theme if no ThemeResolver configured");
  }
  themeResolver.setThemeName(this.request, this.response, (theme != null ? theme.getName() : null));
  this.theme = theme;
}