此案例是基于JavaEE、mysql技术的学生信息管理系统。
为了先对案例有个清楚的认识，这里先贴上运行结果截图：
1、索引页面，进入系统。
2、主页面：
3、点击添加：
4、删除李琦琦一栏：
5、修改马衍硕：
一、对数据库的封装：
在数据库库部分，通过Java代码对数据库操作进行封装，其中涉及到很多技术和技巧，请持续关注我的博客，后续会有详细介绍。
对数据库的封装代码：
（1）这里是定义数据库操作元素的结构，操作元素有三个属性，即deptno、dname、loc，分别对应学生信息的学号、姓名、家庭住址。
Dept.java
package com.neusoft.dao;
//实体类
public class Dept {
private int deptno;//
private String dname;//
private String loc;//
private String value1;//
private String value2;//
public int getDeptno() {
return deptno;
}
public void setDeptno(int deptno) {
this.deptno = deptno;
}
public String getDname() {
return dname;
}
public void setDname(String dname) {
this.dname = dname;
}
public String getLoc() {
return loc;
}
public void setLoc(String loc) {
this.loc = loc;
}
public String getValue1() {
return value1;
}
public void setValue1(String value1) {
this.value1 = value1;
}
public String getValue2() {
return value2;
}
public void setValue2(String value2) {
this.value2 = value2;
}
}
（2）连接数据库：
DeUtils.java
package com.neusoft.dao;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class DbUtils {
private DbUtils(){}
private static final String url="jdbc:mysql://localhost:3306/smartstyle";;
private static final String user="root";
private static final String password="857289";
static
{
//1.创建驱动类对象
//new oracle.jdbc.driver.OracleDriver();
try {
//Class.forName("oracle.jdbc.driver.OracleDriver");
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static Connection getConnection()
{
Connection conn=null;
try {
conn=DriverManager.getConnection(url, user, password);
System.out.println("Ok");
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return conn;
}
public static void closeConnection(Connection conn)
{
try {
if(conn!=null)
{
conn.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void closePreparedStatement(PreparedStatement pstmt)
{
try {
if(pstmt!=null)
{
pstmt.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void closeResultSet(ResultSet rs)
{
//4.关闭数据库
try {
if(rs!=null)
{
rs.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void beginTransaction(Connection conn) {
try {
conn.setAutoCommit(false);
} catch (SQLException ex) {
ex.printStackTrace();
}
}
public static void commit(Connection conn) {
try {
conn.commit();
conn.setAutoCommit(true);
} catch (SQLException ex) {
ex.printStackTrace();
}
}
public static void rollback(Connection conn) {
try {
conn.rollback();
conn.setAutoCommit(true);
} catch (SQLException ex) {
ex.printStackTrace();
}
}
public static void main(String[] ars)
{
getConnection();
}
}
（3）对数据库操作的封装：
这里的接口定义了对数据库操作的方法：
DeptDao.java
package com.neusoft.dao;
import java.util.List;
public interface DeptDao {
void insertDept(Dept dept);
void updateDept(Dept dept);
void deleteDept(int deptno);
List<Dept> getDepts();
Dept getDeptByDeptno(int deptno);
}
这里实现了对数据库操作的封装：
在建立数据库连接的基础上，通过向数据库发送要执行的SQL语句，达到操作数据库的目的。
DeptDaoImpl.java
package com.neusoft.dao;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class DeptDaoImpl implements DeptDao {
@Override
public void insertDept(Dept dept) {
// TODO Auto-generated method stub
Connection conn=null;
PreparedStatement pstmt=null;
try {
conn=DbUtils.getConnection();
//3.操作数据库
String sql="insert into dept(deptno,dname,loc) values(?,?,?)";
pstmt=conn.prepareStatement(sql);
pstmt.setInt(1, dept.getDeptno());
pstmt.setString(2, dept.getDname());
pstmt.setString(3,dept.getLoc());
pstmt.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
//4.关闭数据库
DbUtils.closePreparedStatement(pstmt);
DbUtils.closeConnection(conn);
}
}
@Override
public void updateDept(Dept dept) {
// TODO Auto-generated method stub
Connection conn=null;
PreparedStatement pstmt=null;
try {
conn=DbUtils.getConnection();
String sql="update dept set dname=?,loc=? where deptno=?";
pstmt=conn.prepareStatement(sql);
pstmt.setString(1, dept.getDname());
pstmt.setString(2, dept.getLoc());
pstmt.setInt(3, dept.getDeptno());
pstmt.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
//4.关闭数据库
DbUtils.closePreparedStatement(pstmt);
DbUtils.closeConnection(conn);
}
}
@Override
public void deleteDept(int deptno) {
// TODO Auto-generated method stub
Connection conn=null;
PreparedStatement pstmt=null;
try {
conn=DbUtils.getConnection();
String sql="delete from dept where deptno=?";
pstmt=conn.prepareStatement(sql);
pstmt.setInt(1, deptno);
pstmt.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
//4.关闭数据库
DbUtils.closePreparedStatement(pstmt);
DbUtils.closeConnection(conn);
}
}
@Override
public List<Dept> getDepts() {
Connection conn=null;
PreparedStatement pstmt=null;
ResultSet rs=null;
List<Dept> depts=new ArrayList<Dept>();
try {
conn=DbUtils.getConnection();
//3.操作数据库
String sql="select * from dept";
pstmt=conn.prepareStatement(sql);
rs=pstmt.executeQuery();
while(rs.next())
{
Dept dept=new Dept();
dept.setDeptno(rs.getInt("DEPTNO"));//
dept.setDname(rs.getString("DNAME"));
dept.setLoc(rs.getString("LOC"));
depts.add(dept);
}
}catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
DbUtils.closeResultSet(rs);
DbUtils.closePreparedStatement(pstmt);
DbUtils.closeConnection(conn);
}
return depts;
}
@Override
public Dept getDeptByDeptno(int deptno) {
Connection conn=null;
PreparedStatement pstmt=null;
ResultSet rs=null;
Dept dept=new Dept();
try {
conn=DbUtils.getConnection();
//3.操作数据库
String sql="select * from dept where deptno=?";
pstmt=conn.prepareStatement(sql);
pstmt.setInt(1, deptno);
rs=pstmt.executeQuery();
if(rs.next())
{
dept.setDeptno(rs.getInt("DEPTNO"));
dept.setDname(rs.getString("DNAME"));
dept.setLoc(rs.getString("LOC"));
}
}catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
DbUtils.closeResultSet(rs);
DbUtils.closePreparedStatement(pstmt);
DbUtils.closeConnection(conn);
}
return dept;
}
}
（4）为了代码的简洁，再封装：
DeptService.java
package com.neusoft.service;
import java.util.List;
import com.neusoft.dao.Dept;
public interface DeptService {
void insertDept(Dept dept);
void updateDept(Dept dept);
void deleteDept(int deptno);
List<Dept> getDepts();
Dept getDeptByDeptno(int deptno);
}
DeptServiceImpl.java
package com.neusoft.service;
import java.util.List;
import com.neusoft.dao.Dept;
import com.neusoft.dao.DeptDao;
import com.neusoft.dao.DeptDaoImpl;
public class DeptServiceImpl implements DeptService {
@Override
public void insertDept(Dept dept) {
// TODO Auto-generated method stub
DeptDao deptDao=new DeptDaoImpl();
deptDao.insertDept(dept);
}
@Override
public void updateDept(Dept dept) {
// TODO Auto-generated method stub
DeptDao deptDao=new DeptDaoImpl();
deptDao.updateDept(dept);
}
@Override
public void deleteDept(int deptno) {
// TODO Auto-generated method stub
DeptDao deptDao=new DeptDaoImpl();
deptDao.deleteDept(deptno);
}
@Override
public List<Dept> getDepts() {
DeptDao deptDao=new DeptDaoImpl();
return deptDao.getDepts();
}
@Override
public Dept getDeptByDeptno(int deptno) {
// TODO Auto-generated method stub
DeptDao deptDao=new DeptDaoImpl();
return deptDao.getDeptByDeptno(deptno);
}
}
贴个代码分布图
这样，mysql的连接封装基本完成，接下来是web部分。
二、Web部分:
1、各个页面的JSP代码：
（1）index页面：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<a href="DeptServlet?service=all">学生信息管理系统</a>
</body>
</html>
（2）主页面：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" import="java.util.List,com.neusoft.dao.Dept"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="<%=basePath %>dept/insert.jsp" method="post">
<table border="1" width="80%" align="center" cellspacing="0">
<caption>学生信息表</caption>
<tr><th>学生学号</th><th>学生姓名</th><th>家庭地址</th><th>操作</th><tr>
<%List<Dept> depts=(List<Dept>)request.getAttribute("depts");
if(depts==null)
{
%>
<tr><td colspan="3">没有符合条件的数据</td></tr>
<%}else{
for(Dept dept:depts)
{
%>
<tr><td><%=dept.getDeptno() %></td>
<td><%=dept.getDname() %></td>
<td><%=dept.getLoc() %></td>
<td><a href="DeptServlet?service=modify&deptno=<%=dept.getDeptno()%>">修改</a>
<a href="DeptServlet?service=delete&deptno=<%=dept.getDeptno() %>" >删除</a></td>
<tr>
<%}} %>
</table>
<input type="submit" value="添加" >
</form>
</body>
</html>
（3）修改页面：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" import="com.neusoft.dao.Dept"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="<%=basePath %>DeptServlet?service=update" method="post">
<center>
<h1>修改信息</h1>
<% Dept dept=(Dept)request.getAttribute("dept"); %>
学生学号：<input type="text" name="deptno" value="<%=dept.getDeptno() %>"><br>
学生姓名:<input type="text" name="dname" value="<%=dept.getDname() %>"><br>
家庭地址：<input type="text" name="loc" value="<%=dept.getLoc()%> "><br>
<input type="submit" value="修改信息">
</body>
</html>
2、服务器端：
对于客户端不同的HTTP请求对数据库进行不同的操作，并跳转页面。
package com.neusoft.controller;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.neusoft.dao.Dept;
import com.neusoft.service.DeptService;
import com.neusoft.service.DeptServiceImpl;
/**
* Servlet implementation class DeptServlet
*/
@WebServlet("/DeptServlet")
public class DeptServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* Default constructor.
*/
public DeptServlet() {
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
this.doPost(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
String service=request.getParameter("service");
if("all".equals(service))
{
DeptService deptService=new DeptServiceImpl();
List<Dept> depts=deptService.getDepts();
request.setAttribute("depts", depts);
request.getRequestDispatcher("dept/main.jsp").forward(request, response);
}else if("add".equals(service))
{
//处理请求
int deptno=Integer.parseInt(request.getParameter("deptno"));
String dname=request.getParameter("dname");
String loc=request.getParameter("loc");
Dept dept=new Dept();
dept.setDeptno(deptno);
dept.setDname(dname);
dept.setLoc(loc);
//调用相应的业务逻辑
DeptService deptService=new DeptServiceImpl();
deptService.insertDept(dept);
//找到某个视图响应回去
request.getRequestDispatcher("DeptServlet?service=all").forward(request, response);
}else if("update".equals(service))
{
//处理请求
int deptno=Integer.parseInt(request.getParameter("deptno"));
String dname=request.getParameter("dname");
String loc=request.getParameter("loc");
Dept dept=new Dept();
dept.setDeptno(deptno);
dept.setDname(dname);
dept.setLoc(loc);
//调用相应的业务逻辑
DeptService deptService=new DeptServiceImpl();
deptService.updateDept(dept);
//找到某个视图响应回去
request.getRequestDispatcher("DeptServlet?service=all").forward(request, response);
}
else if("delete".equals(service))
{
int deptno=Integer.parseInt(request.getParameter("deptno"));
//调用相应的业务逻辑
DeptService deptService=new DeptServiceImpl();
deptService.deleteDept(deptno);
//找到某个视图响应回去
request.getRequestDispatcher("DeptServlet?service=all").forward(request, response);
}else if("modify".equals(service))
{
int deptno=Integer.parseInt(request.getParameter("deptno"));
//调用相应的业务逻辑
DeptService deptService=new DeptServiceImpl();
Dept dept= deptService.getDeptByDeptno(deptno);
request.setAttribute("dept", dept);
//找到某个视图响应回去
request.getRequestDispatcher("dept/update.jsp").forward(request, response);
}
}
}
完整项目我已上传至我的资源
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