servlet file
String str = req.getParameter("str");
req.setAttribute("str", "java");
getServletContext().getRequestDispatcher("/us.jsp").forward(req, resp);
jsp file
<jsp:useBean id="str" class="hws" scope="request">
or
<div align="center">
<textarea readonly name="" cols="50" rows="25"><%= request.getAttribute("str") %></ textarea>
</div>
<form action="/us" method="post">
<div align="center">
开发者_高级运维 <textarea name="str" cols="50" rows="3">welcome to my program</textarea>
</div>
</form>
Use EL (Expression Language, those ${}
things). It has implicit access to request/session/application scoped attributes by just its attribute name.
<textarea readonly>${str}</textarea>
Be careful with XSS though whenever it concerns user-controlled input.
See also:
- JSP tag info page
- Servlets tag info page
While BalusC is correct, I wanted to point out the potential security risk with directly outputting a string. According to the Java Servlet 2.0 spec,
In cases where escaping is desired (for example, to help prevent cross-site scripting attacks), the JSTL core tag can be used.
For example:
<c:out value=”${anELexpression}” />
This can help protected against XSS attacks. See the OWASP page for more info.
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