jsp怎么写增删改查代码?

下面的代码即可实现（对数据库的 *** 作）：

<%@ page

  language="java"

  contentType="text/html charset=UTF-8"

  pageEncoding="UTF-8"

%>

<%@page import="java.sql.*"%>

<center>

<H1> <font color="blue" size="12">管理中心</font></H1>

<HR />

<table  width="80%"  border="1">

  <tr>

    <th>ID</th>

    <th>书名</th>

    <th>作者</th>

    <th>价格</th>

    <th>删除</th>

 </tr>

  <%                                                           

   // 数据库的名字

    String dbName = "zap"

    // 登录数据库的用户名

    String username = "sa"

    // 登录数据库的密码

    String password = "123"

    // 数据库的IP地址，本机可以用 localhost 或者 127.0.0.1

    String host = "127.0.0.1"

    // 数据库的端口，一般不会修改，默认为1433

    int port = 1433

    String connectionUrl = "jdbc:sqlserver://" + host + ":" + port + "databaseName=" + dbName + "user=" + username

        + "password=" + password

    //

    //声明需要使用的资源   

    // 数据库连接，记得用完了一定要关闭

    Connection con = null

    // Statement 记得用完了一定要关闭

    Statement stmt = null

    // 结果集，记得用完了一定要关闭

    ResultSet rs = null

    try {

      // 注册驱动   

      Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver")

      // 获得一个数据库连接

      con = DriverManager.getConnection(connectionUrl)

      String SQL = "SELECT * from note"

      // 创建查询

      stmt = con.createStatement()

      // 执行查询，拿到结果集

      rs = stmt.executeQuery(SQL)

     while (rs.next()) {

         %>

     <tr>

      <td>

     <%=rs.getInt(1)%>

      </td>

      <td>

       <a href="prepareupdate?ID=<%=rs.getInt("ID")%>" target="_blank"><%=rs.getString(2)%></a>

      </td>

      <td>

       <%=rs.getString(3)%>

      </td>

      <td>

       <%=rs.getString(4)%>

      </td>

      <td>

      <a href="delete?ID=<%=rs.getInt("ID")%>" target="_blank">删除</a>

     </td>

    </tr>

    <%

     }

} catch (Exception e) {

      // 捕获并显示异常

      e.printStackTrace()

    } finally {

      // 关闭我们使用过的资源

      if (rs != null)

        try {

          rs.close()

        } catch (Exception e) {}

      if (stmt != null)

        try {

          stmt.close()

        } catch (Exception e) {}

      if (con != null)

        try {

          con.close()

        } catch (Exception e) {}

    }

  %>

</table>

 <a href="insert.jsp">添加新纪录</a>

</center>

问题太抽象，/*

* To change this template, choose Tools | Templates

* and open the template in the editor.

*/package ******

import java.io.PrintWriter

import java.sql.*/**

* @author wfg

*/

public class DB_Conn {

private String driverName = "com.mysql.jdbc.Driver" //JDBC驱动

private String userName = "root" //数据库用户名

private String userPwd = "*****" //数据库用户密码

private String dbName = "******"//数据库名

private String url = "jdbc:mysql://localhost:3306/"+dbName+"?user="+userName+

"&password="+userPwd //数据库连接字符串

private Connection conn = null//数据库连接对象

public Statement sm = null//数据库语句对象

private PrintWriter out = null //建立数据库连接函数

public void ConnectDB(){

try{

Class.forName(driverName).newInstance()

conn = DriverManager.getConnection(url)

sm = conn.createStatement()

}

catch(Exception e){

e.printStackTrace()

out.print("数据库连接失败！")

}

}//释放数据库连接函数

public void CloseDB(){

try{

if(sm != null){

sm.close()

}

conn.close()

}

catch(SQLException SqlE){

SqlE.printStackTrace()

out.print("数据库关闭失败！")

}

}

}

这是先建立连接

还有这样的需求呀？无奇不有……

写的dao的实现就行了呀 ，何必得要jsp呢？用jsp，只会越来越乱^

CustomerDao.java

package cn.itcast.dao

import java.util.List

import cn.itcast.domain.Customer

public interface CustomerDao {

public void add(Customer customer)

public Customer find(int id)

public List getAllCustomer()

public void delete(int id)

public void update(Customer customer)

public int getAllRecord()

public List getCustomerByPage(int startindex,int pagesize)

}

CustomerDaoJdbcImpl.java

package cn.itcast.dao.impl

import java.sql.Connection

import java.sql.PreparedStatement

import java.sql.ResultSet

import java.util.ArrayList

import java.util.List

import cn.itcast.dao.CustomerDao

import cn.itcast.domain.Customer

import cn.itcast.util.JdbcUtils

public class CustomerDaoJdbcImpl implements CustomerDao {

/*

id int primary key auto_increment,

name varchar(20) not null,

sex varchar(4) not null,

birthday date,

cellphone varchar(20) not null,

Email varchar(40),

preference varchar(100),

type varchar(40),

Description varchar(255)

*/

public void add(Customer customer) {

Connection conn = null

PreparedStatement st = null

ResultSet rs = null

try{

conn = JdbcUtils.getConnection()

String sql = "insert into customer(name,sex,birthday,cellphone,email,preference,type,description) values(?,?,?,?,?,?,?,?)"

st = conn.prepareStatement(sql)

st.setString(1, customer.getName())

st.setString(2, customer.getSex())

st.setDate(3, new java.sql.Date(customer.getBirthday().getTime()))

st.setString(4, customer.getCellphone())

st.setString(5, customer.getEmail())

st.setString(6, customer.getPreference())

st.setString(7, customer.getType())

st.setString(8, customer.getDescription())

st.executeUpdate()

}catch(Exception e){

throw new RuntimeException(e)

}finally{

JdbcUtils.release(rs, st, conn)

}

}

public void delete(int id) {

Connection conn = null

PreparedStatement st = null

ResultSet rs = null

try{

conn = JdbcUtils.getConnection()

String sql = "delete from customer where id=?"

st = conn.prepareStatement(sql)

st.setInt(1, id)

st.executeUpdate()

}catch(Exception e){

throw new RuntimeException(e)

}finally{

JdbcUtils.release(rs, st, conn)

}

}

public Customer find(int id) {

Connection conn = null

PreparedStatement st = null

ResultSet rs = null

try{

conn = JdbcUtils.getConnection()

String sql = "select id,name,sex,birthday,cellphone,email,preference,type,description from customer where id=?"

st = conn.prepareStatement(sql)

st.setInt(1, id)

rs = st.executeQuery()

if(rs.next()){

Customer c = new Customer()

c.setId(rs.getInt("id"))

c.setName(rs.getString("name"))

c.setSex(rs.getString("sex"))

c.setBirthday(rs.getDate("birthday"))

c.setCellphone(rs.getString("cellphone"))

c.setEmail(rs.getString("email"))

c.setPreference(rs.getString("preference"))

c.setType(rs.getString("type"))

c.setDescription(rs.getString("description"))

return c

}

return null

}catch(Exception e){

throw new RuntimeException(e)

}finally{

JdbcUtils.release(rs, st, conn)

}

}

/*

Id 编号 varchar(20)

name 客户姓名 varchar(20)

sex 性名 varchar(4)

birthday 生日 date

cellphone 手机 varchar(20)

Email 电子邮件 varchar(40)

preference 客户爱好 varchar(100)

type 客户类型 varchar(40)

Description 备注 varchar(255)

*/

public List getAllCustomer() {

Connection conn = null

PreparedStatement st = null

ResultSet rs = null

try{

conn = JdbcUtils.getConnection()

String sql = "select id,name,sex,birthday,cellphone,email,preference,type,description from customer order by id"

st = conn.prepareStatement(sql)

rs = st.executeQuery()

List list = new ArrayList()

while(rs.next()){

Customer c = new Customer()

c.setId(rs.getInt("id"))

c.setName(rs.getString("name"))

c.setSex(rs.getString("sex"))

c.setBirthday(rs.getDate("birthday"))

c.setCellphone(rs.getString("cellphone"))

c.setEmail(rs.getString("email"))

c.setPreference(rs.getString("preference"))

c.setType(rs.getString("type"))

c.setDescription(rs.getString("description"))

list.add(c)

}

return list

}catch(Exception e){

throw new RuntimeException(e)

}finally{

JdbcUtils.release(rs, st, conn)

}

}

public void update(Customer customer) {

Connection conn = null

PreparedStatement st = null

ResultSet rs = null

try{

conn = JdbcUtils.getConnection()

String sql = "update customer set name=?,sex=?,birthday=?,cellphone=?,email=?,preference=?,type=?,description=? where id=?"

st = conn.prepareStatement(sql)

st.setString(1, customer.getName())

st.setString(2, customer.getSex())

st.setDate(3, new java.sql.Date(customer.getBirthday().getTime()))

st.setString(4, customer.getCellphone())

st.setString(5, customer.getEmail())

st.setString(6, customer.getPreference())

st.setString(7, customer.getType())

st.setString(8, customer.getDescription())

st.setInt(9, customer.getId())

st.executeUpdate()

}catch(Exception e){

throw new RuntimeException(e)

}finally{

JdbcUtils.release(rs, st, conn)

}

}

public int getAllRecord() {

Connection conn = null

PreparedStatement st = null

ResultSet rs = null

try{

conn = JdbcUtils.getConnection()

String sql = "select count(*) from customer"

st = conn.prepareStatement(sql)

rs = st.executeQuery()

if(rs.next()){

return rs.getInt(1)

}

return 0

}catch(Exception e){

throw new RuntimeException(e)

}finally{

JdbcUtils.release(rs, st, conn)

}

}

public List getCustomerByPage(int startindex, int pagesize) {

Connection conn = null

PreparedStatement st = null

ResultSet rs = null

try{

conn = JdbcUtils.getConnection()

String sql = "select id,name,sex,birthday,cellphone,email,preference,type,description from customer limit ?,?"

st = conn.prepareStatement(sql)

st.setInt(1, startindex)

st.setInt(2, pagesize)

rs = st.executeQuery()

List list = new ArrayList()

while(rs.next()){

Customer c = new Customer()

c.setId(rs.getInt("id"))

c.setName(rs.getString("name"))

c.setSex(rs.getString("sex"))

c.setBirthday(rs.getDate("birthday"))

c.setCellphone(rs.getString("cellphone"))

c.setEmail(rs.getString("email"))

c.setPreference(rs.getString("preference"))

c.setType(rs.getString("type"))

c.setDescription(rs.getString("description"))

list.add(c)

}

return list

}catch(Exception e){

throw new RuntimeException(e)

}finally{

JdbcUtils.release(rs, st, conn)

}

}

}

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