Question

我在一个带有几个输入参数的servlet中有一个HTML表单，当我按下Submit按钮时，我想从表单中获取值并将其写入文件。我不确定如何捕获在下一个.jsp中使用的parms。这是我的代码：

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;
import java.text.*;
import java.util.Random;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.StringTokenizer;


public class CreateCust extends HttpServlet {
  public void doGet(HttpServletRequest request,
                    HttpServletResponse response)
      throws ServletException, IOException {
    HttpSession session = request.getSession();

    // Generate a Customer Account using the Random Number Generator
    // Calculate Confirmation Number
    Random randomGenerator = new Random();
    int custNum = randomGenerator.nextInt(10000);
    String custId = "CST" + custNum;

    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    String title = "Customer Profile Information";
    String MainPageURL =
          response.encodeURL("/csj/CustomerAccounts.html");
    String docType =
      "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 " +
      "Transitional//EN\">\n";
    out.println(docType +
                "<HTML>\n" +
                "<HEAD><TITLE>" + title + "</TITLE></HEAD>\n" +
                "<BODY BGCOLOR=\"#FDF5E6\">\n" +
                "<H1 ALIGN=\"CENTER\">" + title + "</H1>");

    out.println("<BR>" +
        "<BR>" +
        "<a href=" + MainPageURL + ">Previous Page</a>");  

        out.println
          ("<Form>\n" +   
          "<CENTER>" +
            "Please Enter the following Information:\n" +

            "<TABLE border=1>" +
            "<TR>" +
            "<TD>" +
            "Customer ID: " +  
            "</TD>" +
            "<TD>" +
            "<Label>" + custId + " </Label>\n" +
            "</TD>" +
            "</TR>" +
            "<TR>" +
            "<TD>" +
            "Name:" +
            "</TD>" +
            "<TD>" +
            "<Input type=\"Text\" name=\"F_name\" </input>\n" +
            "</TR>" +

            "<BR>" +
            "<TR>" +
            "<TD>" +
            "Street Address:" +
            "</TD>" +
            "<TD>" +
            "<Input type=\"Text\" name=\"F_Add1\" </input>\n" +
            "</TD>" +
            "</TR>" +
            "<BR>" +
            "<TR>" +
            "<TD>" +
            "Apt or Suite:" +
            "</TD>" +
            "<TD>" +
            "<Input type=\"Text\" name=\"F_Add2\" </input>\n" + 
            "</TD>" +
            "</TR>" +
            "<BR>" +
            "<TR>" +
            "<TD>" +
            "City:" +
            "</TD>" +
            "<TD>" +
            "<Input type=\"Text\" name=\"F_City\" </input>\n" +
            "</TD>" +
            "</TR>" +
            "<BR>" +
            "<TR><TD>" +
            "State:" +
            "</TD><TD>" +
            "<Input type=\"Text\" name=\"F_state\" </input>\n" +
            "</TD>" +
            "</TR>" +
            "<BR>" +
            "<TR><TD>" +
            "Zip Code:" +
            "</TD>" +
            "<TD>" +
            "<Input type=\"Text\" name=\"F_Zip\" </input>\n" +
            "</TD>" +
            "</TR>" +
            "<BR>" +
            "<TR>" +
            "<TD>" +
            "Phone Number:" +
            "</TD>" +
            "<TD>" +
             "<Input type=\"Text\" name=\"F_Phone\" </input>\n" +
            "</TD>" +
            "</TR>" +
            "<BR>" +
            "<TR><TD>" +
            "Cable Plan:" +
            "</TD>" +
            "<TD>" +
            "<select>\n" +
                "<option value=\"selcab\">Select Cable</option>\n" +
                "<option value=\"Basic50\">Basic50</option>\n" +
                "<option value=\"Basic100\">Basic100</option>\n" +
                "<option value=\"Ultimate200\">Ultimate200</option>\n" +
            "</select>\n" +
            "</TD>" +
            "</TR>" +
            "<BR>" +
            "<TR><TD>" +
            "Internet Plan:" +
            "</TD>" +
            "<TD>" +
            "<select>\n" +
                "<option value=\"selInt\">Select Internet</option>\n" +
                "<option value=\"speedlane\">SpeedLane</option>\n" +
                "<option value=\"lightlane\">LightLane</option>\n" +
            "</select>\n" +
            "</TD>" +
            "</TR>" +
            "<TABLE>" +


            "</CENTER>" +
            "</Form>"  );




        String confirmURL =
          response.encodeURL("/csj/ConfirmCust");
        // "Proceed to Checkout" button below table
        out.println
          ("</TABLE>\n" +
           "<FORM ACTION=\"" + confirmURL + "\">\n" +
           "<BIG><CENTER>\n" +
           "<INPUT TYPE=\"SUBMIT\"\n" +
           "       VALUE=\"Create Account\">\n" +

           "</CENTER></BIG>" +
           "</FORM>");


      out.println("</BODY></HTML>");
    }
    }

Answer 1

当我按下提交按钮时，我想从表单中获取值

为此，你必须request.getParameter("input parameter name");

在你的servlet中你有两个表单，一个有动作而另一个没有。

见这个

out.println
          ("</TABLE>\n" +
           "<FORM ACTION=\"" + confirmURL + "\">\n" +
           "<BIG><CENTER>\n" +
           "<INPUT TYPE=\"SUBMIT\"\n" +
           "       VALUE=\"Create Account\">\n" +

           "</CENTER></BIG>" +
           "</FORM>");

此处存在表单操作，但是当您按下提交时，它会调用confirmURL但会传递mo值（因为它没有任何输入参数）。

现在在此

out.println
          ("<Form>\n" +   
          "<CENTER>" +
            "Please Enter the following Information:\n" +

            "<TABLE border=1>" +
            "<TR>" +
            "<TD>" +
            "Customer ID: " +  
            "</TD>" +
            "<TD>" +
            "<Label>" + custId + " </Label>\n" +
 ....................

输入参数存在但没有提交按钮和表单操作因此不会执行任何操作，因此不会传递任何值。

捕获FORM值以在POST中更新

1 个答案: