Question

我是java编程的新手，我正在尝试使用struts将一个值从servlet传递给jsp中的javascript。

servlet类 -

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.actions.DispatchAction;

import net.sf.json.JSONObject;
import net.sf.json.JSONArray;

public class handler extends org.apache.struts.actions.DispatchAction{

    private static final String SUCCESS = "success";

    public ActionForward Add(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response)throws Exception {

        actionFileAndDB obj=new actionFileAndDB();
        JSONArray list=obj.view();
        request.setAttribute("jsonArray",list);

        System.out.println("this is being called");

        String s="Karthikeyan";
        request.setAttribute("myname",s);       

        return mapping.findForward(SUCCESS);
    }
}

JSP -

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import="net.sf.json.JSONObject"%>
<%@page import="net.sf.json.JSONArray"%>

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>View</title>
    </head>
    <body>
        <form action="operations.do">
            <table>
                <tr>
                    <td>
                        <select value="s"  name="dropdown">
                            <option>VIEW</option>
                            <option>Database</option>
                            <option>File</option>
                            <option>Both</option>
                        </select>
                    </td>
                    <td>
                        <input type="button" value="Add" name="actionMethod" onclick="javascript:viewData();" />
                    </td>
                    <td>
                        <input type="submit" value="Edit" name="actionMethod"/>
                    </td>
                    <td>
                        <input type="submit" value="Delete" name="actionMethod"/>
                    </td>
                </tr>
            </table>
        </form>


        <p id="p1">
        </p>




        <script type="text/javascript">
            function viewData()
            {
                var c="Hello";
                document.getElementById("p1").innerHTML=c;

                //JSONArray j=request.getAttribute("jsonArray");
                //document.getElementById("p1").innerHTML=j;

                //String s=request.getAttribute("myname");
                //document.getElementById("p1").innerHTML=s;

                event.preventDefault();

            }
        </script>


    </body>
</html>

当我取消注释getAttribute（＆＃34; myname＆＃34;）时，段落标记中没有显示任何内容。我想知道是否有任何方法可以在不使用JQuery或Ajax的情况下将值从servlet检索到javascript暂时。

//使用显示的完整代码进行编辑 -

的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">


  <servlet>
    <servlet-name>action</servlet-name>
    <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
    <init-param>
      <param-name>config</param-name>
      <param-value>/WEB-INF/struts-config.xml</param-value>
    </init-param>
    <load-on-startup>2</load-on-startup>
 </servlet>

  <servlet-mapping>
    <servlet-name>action</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>

  <welcome-file-list>
    <welcome-file>view.jsp</welcome-file>
  </welcome-file-list>
</web-app>

的struts-config.xml

<?xml version="1.0" encoding="ISO-8859-1" ?>

<!DOCTYPE struts-config PUBLIC
          "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"
          "http://struts.apache.org/dtds/struts-config_1_3.dtd">

<struts-config>

    <action-mappings>

        <action path="/view" forward="/view.jsp"/>

        <action path="/operations" type="handler" parameter="actionMethod">
            <forward name="success" path="/view.jsp"/>
        </action>

    </action-mappings>



</struts-config>

view.jsp和handler.java已经显示

actionFileAndDB.java

import java.io.*;
import java.lang.*;
import java.sql.*;
import java.util.*;

import java.io.FileWriter;
import java.io.FileReader;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;

import net.sf.json.JSONObject;
import net.sf.json.JSONArray;

public class actionFileAndDB{

    public actionFileAndDB(){}

    public JSONArray view() throws ClassNotFoundException{

        JSONArray list = new JSONArray();

        Connection conn = null;
        Statement stmt = null;

        try{

            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase", "root", "");
            stmt = conn.createStatement();
            String sql;
            sql = "SELECT * FROM employee order by id";
            ResultSet rs = stmt.executeQuery(sql);

            while (rs.next()) {

                JSONObject obj = new JSONObject();

                obj.put("id",rs.getString("id"));
                obj.put("name",rs.getString("name"));
                obj.put("mobile",rs.getString("mobile"));
                obj.put("email",rs.getString("email"));
                obj.put("dept",rs.getString("dept"));

                list.add(obj);

                //System.out.println("db: "+list.get(0));
            }

            rs.close();
            stmt.close();
            conn.close();

        }catch(java.sql.SQLException e)
        {
            System.out.println("ERRRORHELLO");
            e.printStackTrace();
        }
        return list;
    }
}

Answer 1

在jsp

中的scriplet <% %>内添加java代码

  function viewData()
    {
        var c="Hello";
        document.getElementById("p1").innerHTML=c;

        <% JSONArray j=request.getAttribute("jsonArray"); %>
        document.getElementById("p1").innerHTML="<%=j%>";

        <%String s=request.getAttribute("myname");%>
        document.getElementById("p1").innerHTML="<%=s%>";

        event.preventDefault();

    }

请参阅此link以获取scriplets

在jsp中将值从servlet传递给javascript

1 个答案: