Servlet实现增删改查功能

MVC模式

 M：Model，即模型，对于JavaBean

 V：View， 即试图，对应JSP页面

 C：Controller，即控制器，对应Servlet

1. 以下为MVC实现一个简单的 增删改查 功能

1> 显示记录

2> 增加一条记录

3> 修改一条记录

4> 删除一条记录

程序源代码：

M层：模型层

1.封装一条信息的所有属性 ，即VO

package ;

/**

* @author help

*封装一条信息的所有属性

*/

public class JavaBean {

private int id;

private String name;

private String password;

private String sex;

private int age;

public int getId() {

return id;

}

public void setId(int id) {

= id;

}

public String getName() {

return name;

}

public void setName(String name) {

= name;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

rd = password;

}

public String getSex() {

return sex;

}

public void setSex(String sex) {

= sex;

}

public int getAge() {

return age;

}

public void setAge(int age) {

= age;

}

}

2.封装数据库连接以及操作JavaBean所用到的方法，即DAO

package ;

import tion;

import Manager;

import edStatement;

import Set;

import eption;

import ist;

import ;

/**

* @author help

*操作数据库的方法

*/

public class SqlBean {

Connection con;

PreparedStatement pre;

ResultSet rs;

public SqlBean()

{

try {

e("");

} catch (ClassNotFoundException e) {

tackTrace();

}

try {

con=nection("jdbc:mysql://127.0.0.1:3306/MyServlet","root","122828");

} catch (SQLException e) {

tackTrace();

}

}

/**

* @author help

*

*插入新的一条记录

* @return

*/

public int getInsert(String sql,JavaBean jBean)

{

int count =0;

try {

pre = eStatement(sql);

ing(1,e());

ing(2,sword());

ing(3,());

(4,());

count=eUpdate();

} catch (SQLException e) {

tackTrace();

}

finally

{

try {

();

();

} catch (SQLException e) {

// TODO Auto-generated catch block

tackTrace();

}

}

return count;

}

/**

* @author help

*

*删除一条记录

* @return

*/

public int getDelete(String sql,int id)

{

int count =0;

try {

pre = eStatement(sql);

(1, id);

count=eUpdate();

} catch (SQLException e) {

tackTrace();

}

finally

{

try {

();

();

} catch (SQLException e) {

// TODO Auto-generated catch block

tackTrace();

}

}

return count;

}

/**

* @author help

*

*根据ID查询某一条记录

* @return

*/

public JavaBean getSearchById(String sql,int id)

{

JavaBean jBean = new JavaBean();

try {

pre = eStatement(sql);

(1, id);

rs=eQuery();

while(())

{

(("id"));

e(ing("name"));

sword(ing("password"));

(ing("sex"));

(("age"));

}

} catch (SQLException e)

{

tackTrace();

}

return jBean;

}

/**

* @author help

*

*更新某一条记录

* @return

*/

public int getUpdate(String sql,JavaBean jBean)

{

int count =0;

try {

}

pre = eStatement(sql);

(5,());

ing(1,e());

ing(2,sword());

ing(3,());

(4,());

count = eUpdate();

} catch (SQLException e) {

// TODO Auto-generated catch block

tackTrace();

}

finally

{

try {

();

();

} catch (SQLException e) {

// TODO Auto-generated catch block

tackTrace();

}

}

return count;

/**

* @author help

*

*显示所有记录

* @return

*/

public List getSearch(String sql)

{

List list = new ArrayList();

//获取prepareStatement对象

try {

pre = eStatement(sql);

rs =eQuery();

while(())

{

JavaBean jBean =new JavaBean();

(("id"));

}

}

e(ing("name"));

sword(ing("password"));

(ing("sex"));

(("age"));

(jBean);

}

} catch (SQLException e) {

// TODO Auto-generated catch block

tackTrace();

}

finally

{

try {

();

();

} catch (SQLException e) {

// TODO Auto-generated catch block

tackTrace();

}

}

return list;

V层：试图层

1. 显示记录集的页面

<%@ page language="java" import=".*" pageEncoding="UTF-8"%>

<%

String path = textPath();

String basePath = eme()+"://"+verName()+":"+verPort()+path+"/";

%>

2. 插入页面

<%@ page language="java" import=".*" pageEncoding="UTF-8"%>

<%

String path = textPath();

String basePath =

eme()+"://"+verName()+":"+verPort()+path+"/";

%>

3. 更新页面

<%@ page language="java" import=".*" pageEncoding="UTF-8"%>

<%

String path = textPath();

String basePath =

eme()+"://"+verName()+":"+verPort()+path+"/";

%>

4. 出错页面

<%@ page language="java" import=".*" pageEncoding="UTF-8"%>

<%

String path = textPath();

String basePath = eme()+"://"+verName()+":"+verPort()+path+"/";

%>

对不起！您<%=ribute("error") %>失败

C层：控制层—Servlet

1.显示记录集的

package t;

import ption;

import tException;

import rvlet;

import rvletRequest;

import rvletResponse;

import an;

import n;

public class SearchById extends HttpServlet {

tentType("text/html");

racterEncoding("utf-8");

racterEncoding("utf-8");

//获取用户ID

String sid = ameter("id");

int id =nt(sid);

String sql ="select * from student where id=?";

SqlBean sBean = new SqlBean();

JavaBean jBean = rchById(sql, id);

//用户ID

ribute("id",());

//用户姓名

ribute("name",e());

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doPost(request,response);

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

private static final long serialVersionUID = 1L;

}

}

//用户密码

ribute("password",sword());

//用户性别

String sex="";

String man="";

String woman="";

if(()!=null)

{

}

ribute("man",man);

ribute("woman",woman);

//用户年龄

ribute("age",());

//转发

uestDispatcher("").forward(request, response);

sex=().trim();

if(("男"))

{

}

else

{

}

woman ="checked";

man ="checked";

2.增加记录的

package t;

import ption;

import tException;

import rvlet;

import rvletRequest;

import rvletResponse;

import n;

import an;

public class Insert extends HttpServlet {

private static final long serialVersionUID = 1L;

}

public void doGet(HttpServletRequest request, HttpServletResponse response)

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

}

throws ServletException, IOException {

throws ServletException, IOException {

tentType("text/html");

doPost(request,response);

tentType("text/html");

racterEncoding("utf-8");

racterEncoding("utf-8");

//获取前台页面数据

String name =ameter("name");

String password =ameter("password");

String sex =ameter("sex");

String sage = ameter("age");

int age =nt(sage);

//封装到JavaBean对象中去

JavaBean jBean = new JavaBean();

e(name);

sword(password);

(sex);

(age);

//调用模型层

String sql = "insert into student(name,password,sex,age) values(?,?,?,?)";

SqlBean sBean = new SqlBean();

int count =ert(sql,jBean);

String url="";

if(count>0)

{

}

else

{

}

//转发

uestDispatcher("").forward(request, response);

url ="";

ribute("error", "");

url="";

3.更新记录的

package t;

import ption;

import riter;

import tException;

import rvlet;

import rvletRequest;

import rvletResponse;

import an;

import n;

public class Update extends HttpServlet {

tentType("text/html");

racterEncoding("utf-8");

racterEncoding("utf-8");

//获得前台表单信息

String sid = ameter("id");

int id =nt(sid);

String name =ameter("name");

String password =ameter("password");

String sex =ameter("sex");

String sage = ameter("age");

int age =nt(sage);

//封装到JavaBean对象中去

JavaBean jBean = new JavaBean();

(id);

e(name);

sword(password);

(sex);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doPost(request,response);

private static final long serialVersionUID = 1L;

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

}

}

(age);

String sql ="update student set name=?,password=?,sex=?,age=? where id=?";

SqlBean sBean = new SqlBean();

int count =ate(sql,jBean);

String url="";

if(count>0)

{

}

else

{

}

uestDispatcher("").forward(request, response);

url ="";

ribute("error", "更新");

url="";

4.删除记录的

package t;

import ption;

import tException;

import rvlet;

import rvletRequest;

import rvletResponse;

import n;

public class Delete extends HttpServlet {

}

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

}

throws ServletException, IOException {

tentType("text/html");

//获取超链接传来的数据

String sId = ameter("id");

int id =nt(sId);

//调用模型层删除方法

String sql = "delete from student where id=?";

SqlBean sBean = new SqlBean();

int count =ete(sql, id);

String url="";

if(count>0)

{

}

else

{

}

//转发

uestDispatcher(url).forward(request, response);

url ="";

ribute("error", "删除");

url="";

tentType("text/html");

doPost(request,response);

private static final long serialVersionUID = 1L;

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

XML文件

xmlns="/xml/ns/javaee"

xmlns:xsi="/2001/XMLSchema-instance"

xsi:schemaLocation="/xml/ns/javaee

/xml/ns/javaee/web-app_2_">

Update

SearchById

ById

Insert

Delete

Update

/Update

SearchById

/SearchById

Insert

/Insert

Delete

/Delete