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java - servlet 给 jsp 传值

转载 作者:塔克拉玛干 更新时间:2023-11-02 20:08:00 26 4
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我想简单地将值 servlet 传递给 jsp 页面。我想运行 jsp 文件并从获取 servlet 显示 onload 数据

但我得到的是空值:"Servlet communicated message to JSP: null "

下面是我的代码。

java代码

package api;

public class ServletToJSP extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

//communicating a simple String message.
String message = "Example source code of Servlet to JSP communication.";
request.setAttribute("message", message);

RequestDispatcher reqDispatcher = getServletConfig().getServletContext().getRequestDispatcher("javaPapers.jsp");
reqDispatcher.forward(request,response);


}
}

jsp文件

<%@ page import="api.ServletToJSP" language="java" %>


<html>
<body>
<%
String message = (String) request.getAttribute("message");
out.println("Servlet communicated message to JSP: "+ message);

// Vector vecObj = (Vector) request.getAttribute("vecBean");
// out.println("Servlet to JSP communication of an object: "+vecObj.get(0));
%>
</body>
</html>

web.xml

<servlet>
<servlet-name>ServletToJSP</servlet-name>
<servlet-class>api.ServletToJSP</servlet-class>
</servlet>
<servlet-mapping>

<servlet-name>ServletToJSP</servlet-name>
<url-pattern>/ServletToJSP/*</url-pattern>
</servlet-mapping>

最佳答案

有几件事要改变:

在 servlet 中

public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//communicating a simple String message.
String message = "Example source code of Servlet to JSP communication.";
request.setAttribute("message", message);
request.getRequestDispatcher("javaPapers.jsp").forward(request,response);
}

在jsp中

<html>
<body>
Servlet communicated message to JSP: ${message}
</body>
</html>

所做的更改:

  • 在 servlet 中,使用 request.getRequestDispatcher(String url)
  • 在 jsp 中,删除了 servlet 导入。
  • 在jsp中,使用EL获取属性值。

关于java - servlet 给 jsp 传值,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18585956/

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