无法使用 requestDispathser 包含 servlet 响应

Question

Index.jsp

<form method="post" action="serv">
Enter Latest Reading <input type="text" name="t1"> <br>
Enter Previous Reading <input type="text" name="t2"> <br>
<input type="submit" value="SEND">  
</form>

LoginServlet.java

@WebServlet("/serv")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

    PrintWriter out = res.getWriter();   
    out.println("<u>Following are your Bill Particulars</u><br><br>");   
    req.setAttribute("unitRate", new Double(8.75));

    req.getRequestDispatcher("/Test").include(req, res); 
    out.println("<br><br>Please pay the bill amount before 5th of every month to avoid penalty and disconnection");   
    out.close();

    }

}

IncludeServlet.java

@WebServlet("/Test")

public class IncludeServlet extends HttpServlet {
    protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

        PrintWriter out = res.getWriter();   
        int latestReading = Integer.parseInt(req.getParameter("t1"));   
        int previousReading = Integer.parseInt(req.getParameter("t2"));   
        Object obj = req.getAttribute("unitRate");
        Double d1 = (Double) obj; 
        double rate = d1.doubleValue();   
        int noOfUnits = latestReading-previousReading; 
        double amountPayable = noOfUnits * rate;   
        out.println("Previous reading: " + previousReading); out.println("<br>Current reading: " + latestReading); 
        out.println("<br>Bill Amount Rs." + amountPayable); 

    }

}

当我运行上面的项目时，在浏览器中只显示LoginServlet的响应，我无法包含IncludeServlet.java的响应。

LoginServlet 的所有 System.out.println("") 仅在控制台显示，而非来自 IncludeServlet。

我也使用调试器，但这不会进入 IncludeServlet.java 页面。

Answer 1

在你的 IncludeServlet 而不是覆盖 doGet 方法覆盖 doPost ，因为 Post 请求来自 HTML

protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
  // do Whatever you want to do .
}

更新： 还要在两个 servlet 中写入 res.setContentType("text/html");，以便在 out.print 中编写的 html 执行，否则您的输出将看起来像 <br><br>Please pay the bill amount before 5th of every month to avoid penalty and disconnection.

无法使用 requestDispathser 包含 servlet 响应

Unable to include servlet response by using requestDispathser

java

jsp

servlets

requestdispatcher