基于mysql数据库支持的留言板的实例
基于mysql数据库支持的留言板的实例
一、创建一个web工程名称：manhongliu
启动MyEclipse—New—WebProject—Project Name:manhongliu—Java EE 5.0—Finish--复制数据库驱动程序mysql-connector-java-5.1.6-bin.jar到工程中—添加到内路径：将鼠标放到驱动程序上右键—Build Path—Add to Build Path
二、创建数据库zhoulanzhen创建表usertable
(1)启动Mysql—创建数据库zhoulanzhen：create database zhoulanzhen;
(2)创建表：usertable：create table usertable(id int(11) auto_increment primary key, name varchar(20) not null,phone varchar(20) not null,email varchar(20), title varchar(40) not null, content varchar(200) not null, time datetime);
三、新建表单AddMessage.htm文件
启动Dreamweaver—新建htm文件—制作表单：各控件的名称是它们自己，如：姓名是name
存盘到：manhongliu的WebRoot中--名字：AddMessage.htm—添加action=”/manhongliu/servlet/AddMessageServlet”这是添加到数据库的servlet
四、新建添加留言内容到数据库的servlet名称：AddMessageServlet.
New—Servlet—Package:com.manhongliu—Name:AddMessageServlet—选Create doPost—Next—Servlet/JSP Mapping URL: /servlet/AddMessageServlet—Finish—编辑AddMessageServlet如下：
package com.manhongliu;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Timestamp;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AddMessageServlet extends HttpServlet
{ //1
private static final long serialVersionUID = 2059282498034052536L;
public void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException,IOException
{ //2
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
int result8=0;
out.println("");
out.println("
out.println(" ");
String driver="com.mysql.jdbc.Driver";
String rul="jdbc:mysql://localhost:3306/zhoulanzhen?";
String username="root";
String password="root";
String sql="insert into usertable(name,phone,email,title,content,time) values(?,?,?,?,?,?)";
try
{ //3
Class.forName(driver);
Connection conn= java.sql.DriverManager.getConnection (rul,username,password);
PreparedStatement pstmt=conn.prepareStatement(sql);
pstmt.setString(1, StringUtil.filterHtml(request.getParameter("name")));
pstmt.setString(2, StringUtil.filterHtml(request.getParameter("phone")));
pstmt.setString(3, StringUtil.filterHtml(request.getParameter("email")));
pstmt.setString(4, StringUtil.filterHtml(request.getParameter("title")));
pstmt.setString(5, StringUtil.filterHtml(request.getParameter("content")));
pstmt.setTimestamp(6, new Timestamp(System.currentTimeMillis()));
result8= pstmt.executeUpdate();
out.println(result8);
if(result8==0)
{
out.println("对不起，留言不成功");
}
else{
out.println("添加成功");
}
pstmt.close();
conn.close();
out.flush();
out.close();
} //3
catch (ClassNotFoundException e)
{ //4
e.printStackTrace();
} //4
catch (SQLException e)
{ //5
e.printStackTrace();
} //5
out.println("");
out.println("");
} //2
} //1
五、创建一个工具类StringUtil包名com.manhongliu起过滤字符的作用，程序代码：
package com.manhongliu;
public class StringUtil
{
public static String filterHtml(String value){
value=value.replaceAll("&", "&");
value=value.replaceAll("<", "<");
value=value.replaceAll(">", ">");
value=value.replaceAll(" ", " ");
value=value.replaceAll("'", "'");
value=value.replaceAll("/"", """);
value=value.replaceAll("/n", "
");
return value;
}
}
六、新建显示留言内容的servlet名称：GetMessageServlet其程序如下：
package com.manhongliu;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class GetMessageServlet extends HttpServlet
{
private static final long serialVersionUID = -2884268876112198563L;
public void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException,IOException
{
request.setCharacterEncoding("gb2312");
response.setCharacterEncoding("gb2312");
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
String driver="com.mysql.jdbc.Driver";
String rul="jdbc:mysql://localhost:3306/zhoulanzhen?";
String username="root";
String password="root";
String sql="select * from usertable";
out.println("");
out.println("
out.println("");
try
{
Class.forName(driver);
Connection conn= java.sql.DriverManager.getConnection (rul,username,password);
PreparedStatement pstmt=conn.prepareStatement(sql);
ResultSet rs=pstmt.executeQuery();
//5.显示结数据库里的数据
while(rs.next()){
printRow(out,rs);
}
rs.close();
pstmt.close();
conn.close();
out.flush();
out.close();
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
}
catch (SQLException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void printRow(PrintWriter out,ResultSet rs)throws SQLException
{
out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println(" out.println("");
");编号： ");
"+rs.getInt("id")+" 姓名： ");
"+rs.getString("name")+" 电话： ");
"+rs.getString("phone")+" 邮箱： ");
"+rs.getString("email")+" 主题： ");
"+rs.getString("title")+" 内容： ");
"+rs.getString("content")+" 时间： ");
"+rs.getString("time")+"
}
}
七、部署运行
http://localhost:8080/manhongliu/AddMessage.htm