Question

我有下一个问题。在jsp页面中，我使用菜单为2个用户（导师和学生）依赖于我选择的角色，我应该包括菜单文件。像这样的Smth

<c:if test="${role eq 'Tutor'}">
                <c:import url="/page/menuForTutor.html" charEncoding="UTF-8"/>
</c:if>
<c:if test="${role eq 'Student'}">
             <c:import url="/page/menuForStudent.html" charEncoding="UTF-8"/>
</c:if>

我应该使用用户描述符

public class MenuTag extends TagSupport{

    private static final String PARAM_ROLE_TUTOR = "Tutor";
    private static final String PARAM_ROLE_STUDENT = "Student";

    @Override
    public int doStartTag(){
        HttpServletRequest request = (HttpServletRequest)pageContext.
                                                   getRequest();
        HttpSession session = request.getSession();
        String role = (String) session.getAttribute("role");
        if (PARAM_ROLE_TUTOR.equals(role)){
            try {
                pageContext.getOut().print("<c:import url=\"/page/menuForTutor.html\" charEncoding=\"UTF-8\"/>");
            } catch (IOException ex) {
                Logger.getLogger(MenuTag.class.getName()).log(Level.SEVERE, null, ex);
            }
        } else if(PARAM_ROLE_STUDENT.equals(role)){
        }
        return SKIP_BODY;
    }       
}

当我使用debag时，我看到我做了所有步骤但是导师的菜单没有在jsp上显示。有什么想法吗？

Answer 1

我认为会话（“角色”）是在另一个代码部分设置的！

将JspWriter设置为out = pageContext.getOut（）;

在代码

中类似

JspFactory  factory     = JspFactory.getDefaultFactory();
PageContext pageContext = factory.getPageContext(
this,
request,
response,
null,  // errorPageURL
false, // needsSession
JspWriter.DEFAULT_BUFFER,
true   // autoFlush
);

    ....
            JspWriter   out     = pageContext.getOut();
            HttpSession session = request.getSession();
            String role = (String) session.getAttribute("role");
            if (PARAM_ROLE_TUTOR.equals(role)){
                try {
                    out.println("<c:import url=\"/page/menuForTutor.html\" charEncoding=\"UTF-8\"/>");
                    out.flush();
                    // Evaluate the body if there is one
                    return EVAL_BODY_BUFFERED;
.......

else return SKIP_BODY;

编辑查看代码：您必须“返回EVAL_BODY_BUFFERED;”

在用户描述符不起作用pageContext.getOut（“<c：import ...>”）</c：import ...>

1 个答案: