How to use

setAttribute

method

in

javax.servlet.http.HttpServletRequest

 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  try {
    List<Product> products = productService.list(); // Obtain all products.
    request.setAttribute("products", products); // Store products in request scope.
    request.getRequestDispatcher("/WEB-INF/products.jsp").forward(request, response); // Forward to JSP page to display them in a HTML table.
  } catch (SQLException e) {
    throw new ServletException("Retrieving products failed!", e);
  }
}

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  String username = request.getParameter("username");
  String password = request.getParameter("password");
  User user = userService.find(username, password);

  if (user != null) {
    request.getSession().setAttribute("user", user); // Login user.
    response.sendRedirect("home"); // Redirect to home page.
  } else {
    request.setAttribute("message", "Unknown username/password. Please retry."); // Store error message in request scope.
    request.getRequestDispatcher("/WEB-INF/login.jsp").forward(request, response); // Forward to JSP page to redisplay login form with error.
  }
}

 public class LoginAction implements Action {

  public String execute(HttpServletRequest request, HttpServletResponse response) throws Exception {
    String username = request.getParameter("username");
    String password = request.getParameter("password");
    User user = userDAO.find(username, password);

    if (user != null) {
      request.getSession().setAttribute("user", user); // Login user.
      return "home"; // Redirect to home page.
    }
    else {
      request.setAttribute("error", "Unknown username/password. Please retry."); // Store error message in request scope.
      return "login"; // Go back to redisplay login form with error.
    }
  }

}

public ActionForward enrolInCycleCourseGroupInvalid(ActionMapping mapping, ActionForm form, HttpServletRequest request,
    HttpServletResponse response) {
  request.setAttribute("cycleEnrolmentBean", getCycleEnrolmentBeanFromViewState());
  request.setAttribute("withRules", request.getParameter("withRules"));
  return mapping.findForward("chooseCycleCourseGroupToEnrol");
}

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  String  pro_code  = request.getParameter("pro_code");
  String  name  = request.getParameter("name");
  String  price  = request.getParameter("price");

  // do something usefull with the parameters here

  // expose the results to the jsp like so:
  request.setAttribute("pro_code", pro_code);  
  request.setAttribute("name", name);  
  request.setAttribute("price",price); 
  RequestDispatcher rd = request.getRequestDispatcher("/studentSearch.jsp");
  rd.forward(request, response);
}

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
    throws ServletException {
  if (request.getAttribute("test2") != null) {
    throw new ServletException("Wrong interceptor order");
  }
  request.setAttribute("test1", "test1");
  request.setAttribute("test1x", "test1x");
  request.setAttribute("test1y", "test1y");
  return true;
}

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
    throws ServletException {
  if (request.getAttribute("test1x") == null) {
    throw new ServletException("Wrong interceptor order");
  }
  if (request.getParameter("abort") != null) {
    return false;
  }
  request.setAttribute("test2", "test2");
  request.setAttribute("test2x", "test2x");
  request.setAttribute("test2y", "test2y");
  return true;
}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  request.setAttribute("myDate", new Date());
  request.getRequestDispatcher("/WEB-INF/index.jsp").forward(request, response);
}

 public void doGet(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

  // fetch the username that was sent in the request
  String username = request.getParameter("username");

  // TODO: verify if the username is taken in the database

  // based on the results set the value
  request.setAttribute("isUsernameTaken", "true");

  RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/register.jsp");

  dispatcher.forward(request, response);      
}

@Test
public void includeOnAttribute() throws Exception {
  given(request.getAttribute(View.PATH_VARIABLES)).willReturn(null);
  given(request.getAttribute(WebUtils.INCLUDE_REQUEST_URI_ATTRIBUTE)).willReturn("somepath");
  given(request.getRequestDispatcher(url)).willReturn(new MockRequestDispatcher(url));
  view.setUrl(url);
  // Can now try multiple tests
  view.render(model, request, response);
  assertEquals(url, response.getIncludedUrl());
  model.forEach((key, value) -> verify(request).setAttribute(key, value));
}

protected void validateParamsAndContinue(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {
  for (Map.Entry<String, String[]> entry : request.getParameterMap().entrySet()) {
    if (entry.getValue() != null && entry.getValue().length >0) {
      for (String s : entry.getValue()) {
        if (hasText(s) && s.contains(NULL_STRING)) {
          response.setStatus(400);
          request.setAttribute("error_message_code", "request.invalid_parameter");
          request.getRequestDispatcher("/error").forward(request,response);
          return;
        }
      }
    }
  }
  chain.doFilter(request, response);
}

  request.removeAttribute(attrName);
else if (attrValue != request.getAttribute(attrName)) {
  request.setAttribute(attrName, attrValue);

final HttpServletResponse mockResponse = createMock(HttpServletResponse.class);
expect(requestMock.getAttribute(A_KEY)).andReturn(A_VALUE);
requestMock.setAttribute(REQUEST_DISPATCHER_REQUEST, true);
requestMock.removeAttribute(REQUEST_DISPATCHER_REQUEST);
dispatcher.forward(requestMock, mockResponse);

 public class AccountServlet extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

  List<Account> accounts = getAccountListFromSomewhere();

  String url="..."; //relative url for display jsp page
  ServletContext sc = getServletContext();
  RequestDispatcher rd = sc.getRequestDispatcher(url);

  request.setAttribute("accountList", accounts );
  rd.forward(request, response);
 }
}

request.setAttribute("typedEntitySection", typedEntitySection);
wrapper.getRequestDispatcher(wrapper.getServletPath()).forward(wrapper, response);
return true;

public ActionForward invalid(ActionMapping mapping, ActionForm actionForm, HttpServletRequest request,
    HttpServletResponse response) {
  final Student student = FenixFramework.getDomainObject(request.getParameter("studentOID"));
  request.setAttribute("student", student);
  request.setAttribute("schemaName", request.getParameter("schemaName"));
  request.setAttribute("manageStatuteBean", getRenderedObject());
  return mapping.findForward("manageStatutes");
}

private void sendToAuthorizePage(HttpServletRequest request, 
    HttpServletResponse response, OAuthAccessor accessor) throws IOException, ServletException {
  String callback = request.getParameter("oauth_callback");
  if (callback == null || callback.length() <= 0) {
    callback = "none";
  }
  String consumer_description = (String)accessor.consumer.getProperty("description");
  request.setAttribute("oauthParam_CONSUMER_DESCRIPTION", consumer_description);
  request.setAttribute("oauthParam_CALLBACK_URL", callback);
  request.setAttribute("oauthParam_REQUEST_TOKEN", accessor.requestToken);
  request.getRequestDispatcher("/WEB-INF/aps/jsp/oauth/authorize.jsp").forward(request, response);
}

 @WebServlet("/product")
public class ProductServlet extends HttpServlet {

  @EJB
  private ProductService productService;

  @Override
  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    Product product = productService.find(request.getParameter("id"));
    request.setAttribute("product", product); // Will be available as ${product} in JSP
    request.getRequestDispatcher("/WEB-INF/product.jsp").forward(request, response);
  }

}

protected String extractToken(HttpServletRequest request) {
  // first check the header...
  String token = extractHeaderToken(request);
  // bearer type allows a request parameter as well
  if (token == null) {
    logger.debug("Token not found in headers. Trying request parameters.");
    token = request.getParameter(OAuth2AccessToken.ACCESS_TOKEN);
    if (token == null) {
      logger.debug("Token not found in request parameters.  Not an OAuth2 request.");
    }
    else {
      request.setAttribute(OAuth2AuthenticationDetails.ACCESS_TOKEN_TYPE, OAuth2AccessToken.BEARER_TYPE);
    }
  }
  return token;
}

@Override
public String resolveThemeName(HttpServletRequest request) {
  // Check request for preparsed or preset theme.
  String themeName = (String) request.getAttribute(THEME_REQUEST_ATTRIBUTE_NAME);
  if (themeName != null) {
    return themeName;
  }
  // Retrieve cookie value from request.
  String cookieName = getCookieName();
  if (cookieName != null) {
    Cookie cookie = WebUtils.getCookie(request, cookieName);
    if (cookie != null) {
      String value = cookie.getValue();
      if (StringUtils.hasText(value)) {
        themeName = value;
      }
    }
  }
  // Fall back to default theme.
  if (themeName == null) {
    themeName = getDefaultThemeName();
  }
  request.setAttribute(THEME_REQUEST_ATTRIBUTE_NAME, themeName);
  return themeName;
}