我用 Java 开发了一个自定义标签库，并在我的 Web 应用程序中使用它。
我不知道为什么，但我的 doTag() 根本没有设置 cookie。我已经清除了缓存并重新启动了计算机。这是代码:
public class UserVersionOfSite extends EvenSimplerTagSupport {
private static final Log logger = LogFactory.getLog(UserVersionOfSite.class);
private StringWriter sw = new StringWriter();
@Override
public void doTag() throws IOException, JspException {
getJspBody().invoke(sw); //get the tag body and put it in StringWriter object
//get request object to get cookie value
PageContext ctx = (PageContext)getJspContext();
HttpServletRequest httpServletRequest = (HttpServletRequest) ctx.getRequest();
HttpServletResponse httpServletResponse = (HttpServletResponse) ctx.getResponse();
if(httpServletRequest.getParameterMap().containsKey("show_full_site")) {
logger.debug("show_full_site ");
if(!checkIfCookieExists(httpServletRequest)){
Cookie cookie = new Cookie("SHOW_FULL_SITE",httpServletRequest.getParameter("show_full_site"));
cookie.setMaxAge(86400);
httpServletResponse.addCookie(cookie);
//write the tag output
if(!httpServletRequest.getParameter("show_full_site").equalsIgnoreCase("true")){
//write the response
getJspContext().getOut().println(sw.toString());
}
}else{
String cookieValueString = getCookieValue(httpServletRequest.getCookies(),"SHOW_FULL_SITE","false");
if(!cookieValueString.equalsIgnoreCase("true")){
//write the response
getJspContext().getOut().println(sw.toString());
}
}
}
}
@Override
public String getResult() throws IOException {
return "User version of site";
}
public String getCookieValue(Cookie[] cookies,
String cookieName,
String defaultValue) {
for(int i=0; i<cookies.length; i++) {
Cookie cookie = cookies[i];
if (cookieName.equals(cookie.getName()))
return(cookie.getValue());
}
return(defaultValue);
}
public boolean checkIfCookieExists(HttpServletRequest httpServletRequest){
logger.debug("inside checkIfCookieExists()");
boolean cookiePresent = Arrays.asList(httpServletRequest.getCookies()).contains( "SHOW_FULL_SITE" );
return cookiePresent;
}
}
即使我尝试在不使用 if else 语句的情况下添加代码，但仍然没有成功。我遗漏了什么重要的东西吗？
大家有什么想法吗？我也检查了浏览器的设置，但没有任何东西阻止 cookie 的创建!
最佳答案
我意识到，当我发布此内容时，这匹马可能已经逃跑了，但是，为了其他人绊倒它的利益，我认为该问题可能与此问题中突出显示的 RequestDispatcher 功能有关:unable to add a cookie included in JSP via jsp:include
关于java - 如何在自定义标签中使用doTag方法添加cookie？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14604316/