Question

我的jsp文件必须能够通过网址接收信息。我使用了方法request.getParameter（），但是eclipse没有识别请求，这是一个错误。当我运行这是错误 PWC6199：生成的servlet错误：找不到标志符号：变量请求 location：class org.apache.jsp.stampa_jsp

Thak you

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@page import="java.util.*,java.text.*"
import="java.sql.*" 
 import= "javax.servlet.http.*" 
 import ="javax.servlet.*"%>

<%! 
private String url = "jdbc:derby://localhost:1527/sample;create=true";
private String user= "user"; 
private String pwd ="0000";
public String updateDb(String ur, String us, String p){
    int id=request.getParameter("id");
    //String id = request.getParameter("id");
    int numero= 10;
    String outp="";
    try{
        Connection conn = DriverManager.getConnection(ur,us,p);
        Statement st= conn.createStatement();
        int esito = st.executeUpdate("UPDATE parametri" +" SET numero= "+numero+" WHERE id in ("+id+") ");
        if (esito==1)
        {

            outp=outp+"inserimento eseguito"+" " +"<td><button onclick=\"top.location.href = 'db.jsp"+"'\">Visualizza  DB aggiornato</button></td></tr>"+ "<br>";
            }
        else
            outp= "inserimento non eseguito";
        //rs.close();
        st.close();
        conn.close();
        }
    catch(SQLException e) {outp="Errore nell'accesso al DB";}
    return outp;
    }
%>

错误是行中的请求 int id = request.getParameter（＆＃34; id＆＃34;）;

Answer 1

request.getParameter()的返回类型是字符串，为什么要将它分配给 int ？它会在运行时抛出异常

您可以尝试使用字符串，如下所示：

String id = request.getParameter("id");

JSP文件无法识别请求

1 个答案: