servlet+jsp 增删改查

时间：2015-03-30 22:55:10 阅读：243 评论：0 收藏：0 [点我收藏+]

标签：

个人觉得这种模式是MVC模式

先写一个类，类里面有几个属性。
写一个接口。里面有增删改查的方法。（写在service里）
写一个类实现这个接口（实现里面的增删改查等操作）（写在service里）
连接数据库
写 servlet操作，处理增删改查的信息。
Jsp页面（写页面显示或者上传，添加的页面布局等）与servlet实现交互，从而实现以上功能。

增删改查具体实例如下———— 具体代码：

XinxManager.java

package cn.hpu.service;

import java.util.List;

import cn.hpu.gu.Xinx;

//定义接口增删改查，获取表单信息，通过id获取信息等方法

public interface XinxManager{

public List<Xinx>getXinxs();

public boolean add(Xinx xin);

public boolean del(String id);

public boolean update( Xinx xin);

public boolean select(String name,String password);

public Xinx getXinxById(String id);

}

//定义一个类实现这个接口的方法

XinxManagerImp.Java

package cn.hpu.service;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.Statement;

import java.util.ArrayList;

import java.util.List;

import cn.hpu.gu.Xinx;

import cn.hpu.util.util;

import com.mysql.jdbc.PreparedStatement;

public class XinxManagerImp implements XinxManager{

//增加

public boolean add(Xinx xin) {

boolean flag = false;

//定义一个标志，赋值为false

Connection conn = null;

PreparedStatement pst =null;

conn = util.getConnection();

String sql="insert into report( title,speaker ,address ,unit , time,content ,dateposted)values(?,?,?,?,?,?,?)";

//几个参数几个问号，这里id设置的是自增的所以没必要添加

try{

conn = util.getConnection();

pst = (PreparedStatement) conn.prepareStatement(sql);

//pst.setString(1, xin.getId());

//pst.setInt(1, xin.getId());

//get所要添加的信息，set到数据库对应的位置

pst.seString(, xin.getTitle());

pst.setString(2, xin.getSpeaker());

pst.setString(3, xin.getAddress());

pst.setString(4, xin.getUnit());

pst.setString(5, xin.getTime().toString());

pst.setString(6, xin.getContent());

pst.setString(7,xin.getDateposted().toString());

//executeUpdate(sql)是更新数据，

//返回int类型是返回的更新了多少行，也就是受影响的行数，如果为0，则表示无更新

int rows = pst.executeUpdate();

if(rows>0)

{

flag=true;

}

}catch (Exception e) {

e.printStackTrace();

}finally{

util.close(pst, conn);

}

return flag; //返回flag方便后面的获取

}

//删除

public boolean del(String id) {

boolean flag = false;

Connection conn = null;

PreparedStatement pst = null;

conn = util.getConnection();

try{

String sql = "delete from report where id like?";

pst = (PreparedStatement) conn.prepareStatement(sql);

pst.setString(1, id);

int rows = pst.executeUpdate();

if(rows>0){

flag = true;

}

}catch (Exception e) {

e.printStackTrace();

}finally{

util.close(pst, conn);

}

return flag;

}

//查询

public List<Xinx> getXinxs() {

//用到了类型转换（方法内定义的 public List<Xinx>getXinxs();）

List<Xinx> list = new ArrayList<Xinx>();

Connection conn = null;

ResultSet rs = null; //!!!!!!!

Statement stmt = null;

try{

conn = util.getConnection();

String sql = "select * from report";

//创建Statement (Sql语句的执行环境)

stmt = conn.createStatement();

rs = stmt.executeQuery(sql);

//executeQuery(String sqlString)执行查询数据库的SQL，

//eg:SELECT语句，返回一个结果集（ResultSet）

while( rs.next()){ //！！！！

Xinx xin = new Xinx();

// 查询。类的所有成员信息都set出来

xin.setId(rs.getString("id"));

//解读一下，请求获取字符串，然后都set出来

xin.setSpeaker(rs.getString("speaker")); xin.setAddress(rs.getString("address"));

xin.setTitle(rs.getString("title"));

xin.setTime(rs.getString("time"));

xin.setContent(rs.getString("content"));

xin.setUnit(rs.getString("unit"));

xin.setDateposted(rs.getString("dateposted"));

list.add(xin); //！！！！！！

}

}catch (Exception e) {

e.printStackTrace();

}finally{

util.close(rs, stmt, conn);

}

return list;

}

//修改

public boolean update(Xinx xin){

boolean flag = false;

Connection conn = null;

java.sql.PreparedStatement pst = null;

conn = util.getConnection();

String sql= "update report set title=?,speaker=?,address=?,unit=?,time=?,content=?,dateposted=? where id = "+xin.getId(); //where id = ?"; (两个是一个意思，自where后的东西，是可以替换的，下面会稍作修改，因为多了一个问号)

try{

pst = conn.prepareStatement(sql);

pst.setString(1, xin.getTitle());

pst.setString(2, xin.getSpeaker());

pst.setString(3, xin.getAddress());

pst.setString(4, xin.getUnit());

pst.setString(5, xin.getTime());

pst.setString(6, xin.getContent());

pst.setString(7, xin.getDateposted());

//如果不加这个会出错（Statement parameter 8 not set.）说为设置，所以如果用问号，那就几个问号，设计几个Statement parameter。

//pst.setString(8, xin.getId());

int rows = pst.executeUpdate();

if(rows>0)

{flag = true;}

}catch (Exception e)

{

e.printStackTrace();

}

finally

{

util.close(pst, conn);

}

return flag;

}

//根据id查询它的所有信息

public Xinx getXinxById(String id) {

Connection conn = null;

ResultSet rs = null;

Statement stmt = null;

Xinx xin = new Xinx();

try{

conn = util.getConnection();

String sql = "select * from report where id ="+id;

stmt = conn.createStatement();

rs = stmt.executeQuery(sql);

while(rs.next())

{

//测试一下看看获取id了木有

System.out.println(rs.getString("id")+"通过id查询信息");

if(rs.getString("id").equals(id)) {

//查询显示出来

xin.setId(rs.getString("id"));

xin.setTitle(rs.getString("title"));

xin.setSpeaker(rs.getString("speaker"));

xin.setAddress(rs.getString("address"));

xin.setTime(rs.getString("time"));

xin.setContent(rs.getString("content"));

xin.setUnit(rs.getString("unit"));

xin.setDateposted(rs.getString("dateposted"));

}

}catch (Exception e)

{

e.printStackTrace();

}finally

{

util.close(rs, stmt, conn);

}

System.out.println(xin.getId());

return xin;

}

public boolean select(String name, String password) {

// TODO Auto-generated method stub

return false;

}

addServlet.java

package cn.hpu.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 cn.hpu.gu.Xinx;

import cn.hpu.service.XinxManager;

import cn.hpu.service.XinxManagerImp;

public class AddServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

//防止中文乱码，这样最保险

response.setContentType("text/html;chartset=utf-8");

request.setCharacterEncoding("utf-8");

response.setCharacterEncoding("utf-8");

// request.getParameter（）获取jsp页面提交的数据

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

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

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

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

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

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

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

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

Xinx xin = new Xinx();

//xin.setId(0);

xin.setTitle(title);

xin.setSpeaker(speaker);

xin.setAddress(address);

xin.setUnit(unit);

xin.setTime(time);

xin.setContent(content);

xin.setDateposted(dateposted);

XinxManager xm = new XinxManagerImp();

boolean flag = xm.add(xin);

System.out.println("增加这里的"+flag);

if(flag == true )

//跟上面的意思是一样的if(flag)

{

//作用：增加成功后会调到一个页面，显示出来

Xinx xin1 = xm.getXinxById(id);

//通过id获的这组信息，用setAttribute传到表单页面

request.setAttribute("xin1", xin);

//在 login1.jsp显示新添加的信息，这样一目了然

request.getRequestDispatcher("login1.jsp").forward(request, response);

/*或者直接跳到主页面

//request.setAttribute("param", "success");

System.out.println("添加成功");

//request.getRequestDispatcher("login.jsp").forward(request, response);

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>添加成功</TITLE></HEAD>");

out.println(" <BODY>");

out.println("添加成功！！！");

out.println("<a href = ‘login.jsp‘> 返回主页面</a>");

out.println(" </BODY>");

out.println("</HTML>");

out.flush();

out.close();

}else {

//request.setAttribute("param", "failed");

System.out.println("添加失败");

//如果添加失败转发到原来的页面

request.getRequestDispatcher("add.jsp").forward(request, response);

}

<%@ page language="java" import="java.util.*,cn.hpu.gu.*" pageEncoding="utf-8"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

Login1.jsp

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>My JSP ‘login1.jsp‘ starting page</title>

<!--

-->

</head>

<body>

<h3>增加或者修改后的信息 | <a href="login.jsp">返回主界面</a> </h3>

<tr>

<th>主讲人单位</th>

</tr>

// XinxManager xm = new XinxManagerImp();

// List<Xinx> list = xm.getXinxs();

// if(list!=null)

// {

// for(int i=0; i<list.size(); i++)

// {

// Xinx xin = list.get(i);

Xinx xin =(Xinx)request.getAttribute("xin1");

if(xin!=null)

{

<tr>

<td>

</td>

</tr>

// }

}

</table>

</body>

</html>

DelServlet.Java

package cn.hpu.servlet;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import cn.hpu.service.XinxManager;

import cn.hpu.service.XinxManagerImp;

public class DelServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

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

XinxManager xm = new XinxManagerImp();

boolean flag = xm.del(id);

if(flag == true)

{

response.sendRedirect("login.jsp");

}

Search.java 查询的servlet

package cn.hpu.servlet;

import java.io.IOException;

import java.sql.ResultSet;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.omg.PortableServer.ForwardRequest;

import cn.hpu.gu.Xinx;

import cn.hpu.service.XinxManager;

import cn.hpu.service.XinxManagerImp;

public class Search extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

XinxManager xm = new XinxManagerImp();

List<Xinx> list = xm.getXinxs();

request.setAttribute("list", list);

//转发

request.getRequestDispatcher("login.jsp").forward(request, response);

}

<%@ page language="java" import="java.util.*,cn.hpu.gu.*" pageEncoding="utf-8"%>

<%@page import="cn.hpu.service.XinxManager"%>

<%@page import="cn.hpu.service.XinxManagerImp"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<title>管理员操作页面</title>

<!--

-->

</head>

欢迎${sessionScope.loginuser}登陆

<!--

request.getSession().getAttribute() 与 ${sessionScope} 它们都是取值的,

前面的是java代码，写在java源文件中，或者jsp的<%%>中

后面的属于表达式，直接嵌在HTML代码中取值

-->

<hr/>

<body>

<tr>

<th>主讲人单位</th>

</tr>

XinxManager xm = new XinxManagerImp();

List<Xinx> list = xm.getXinxs();

if(list!=null)

{

for(int i=0; i<list.size(); i++)

{

Xinx xin = list.get(i);

<tr>

<td>

</td>

</tr>

}

</table>

</body>

</html>

UpdateServlet1.java

package cn.hpu.servlet;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import cn.hpu.gu.Xinx;

import cn.hpu.service.XinxManager;

import cn.hpu.service.XinxManagerImp;

public class UpdateServlet1 extends HttpServlet {

//通过login.jsp中的修改跳这，（获取数据库中要更改单的信息）

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

//通过id获取要修改的信息

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

XinxManager xm = new XinxManagerImp();

System.out.println("获取数据库中要更新id的所有信息"+id);

//调用XinxManagerImp.java里的方法

Xinx xin = xm.getXinxById(id);

if(xin != null)

{

//通过id获得的xin的信息用setAttribute方法穿到表单中

request.setAttribute("xin",xin);

//跳转到更改页面

request.getRequestDispatcher("update.jsp").forward(request, response); }

}

update.jsp

<%@ page language="java" import="java.util.*,cn.hpu.gu.*" pageEncoding="utf-8"%>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<!--

-->

</head>

//表单中通过getAttribute获取setAttribute 传来的xin的信息

Xinx xin =(Xinx)request.getAttribute("xin");

<body>

<hr/>

<table>

<inputname="id"type="text"value="<%=xin.getId()%>"style="display: none;"/>

</tr>

</tr>

</tr>

<th>主讲人单位</th> <th><input name="unit" type="text" value="<%=xin.getUnit() %> "></th>

</tr>

</tr>

</tr>

</tr>

</tr>

</table>

</form>

</body>

</html>

UpdateServlet.java

package cn.hpu.servlet;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import cn.hpu.gu.Xinx;

import cn.hpu.service.XinxManager;

import cn.hpu.service.XinxManagerImp;

public class UpdateServlet extends HttpServlet {

//进行数据库中信息修好，也就是重新获取修改后提交的信息

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

this.doPost(request, response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("text/html;chartset=utf-8");

response.setCharacterEncoding("utf-8");

request.setCharacterEncoding("utf-8");

//request.getParameter()方法是获取Http(这里是更改表单)提交过来的数据

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

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

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

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

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

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

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

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

XinxManager xm = new XinxManagerImp();

Xinx xin = new Xinx();

//将新数据set进去。。。

xin.setId(id);

xin.setTitle(title);

xin.setSpeaker(speaker);

xin.setAddress(address);

xin.setUnit(unit);

xin.setTime(time);

xin.setContent(content);

xin.setDateposted(dateposted);

//调用update(Xinx xin)方法{里面将get的新数据信息，再set到数据库中，从而完成修改}

boolean flag = xm.update(xin);

System.out.println("修改后提交的信息"+id);

if(flag == true)

{

//例子

//Student stu1 = sm.getStudentById(id);

//request.setAttribute("stu1",stu1);

Xinx xin1 = xm.getXinxById(id);

request.setAttribute("xin1", xin);

request.getRequestDispatcher("login1.jsp").forward(request, response);

System.out.println(xin.getId()+"9999999999999");

//request.getRequestDispatcher("login.jsp").forward(request, response);

}else

{

}

servlet+jsp 增删改查

标签：

原文地址：http://www.cnblogs.com/guyu/p/4379332.html

踩

(0)

评论一句话评论（0）

分享档案

更多>

2021年07月29日 (22)
2021年07月28日 (40)
2021年07月27日 (32)
2021年07月26日 (79)
2021年07月23日 (29)
2021年07月22日 (30)
2021年07月21日 (42)
2021年07月20日 (16)
2021年07月19日 (90)
2021年07月16日 (35)

周排行