ajax与jsp开发的留言本-处理数据

发布时间:2020-02-06编辑:脚本学堂
一个留言板留言提交与读取的简单实例,不包括回复、编辑与删除等功能。
本实例旨在用一个简单的例子展示如何在java web开发中用javascript开发Ajax应用。

二、servlet
用于对页面提交数据的处理。
package edu.scnu.cn.common.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import edu.scnu.cn.common.DataSql;
import java.sql.*;

public class AddRecordServlet extends HttpServlet ...{

    /** *//**
     *
     */
    private static final long serialVersionUID = 1L;

    /** *//**
     * Constructor of the object.
     */
    public AddRecordServlet() ...{
        super();
    }

    /** *//**
     * Destruction of the servlet. <br>
     */
    public void destroy() ...{
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /** *//**
     * The doGet method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to get.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException ...{

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out
                .println("<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">");
        out.println("<HTML>");
        out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
        out.println("  <BODY>");
        out.print("    This is ");
        out.print(this.getClass());
        out.println(", using the GET method");
        out.println("  </BODY>");
        out.println("</HTML>");
        out.flush();
        out.close();
    }

    /** *//**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException ...{
        DataSql dataSql=new DataSql();
        try ...{
            Connection conn=dataSql.getConn();
            String sql=request.getParameter("sql");           
            try ...{
                int i=dataSql.execute(conn,sql);
                conn.close();
            } catch (SQLException e) ...{
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        } catch (InstantiationException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalAccessException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ClassNotFoundException e) ...{
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
       
    }

    /** *//**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void init() throws ServletException ...{
        // Put your code here
    }
}