DAO设计模版

 1 package cn.mldn.lxh.vo;
 2 
 3 import java.util.Date;
 4 
 5 public class Emp {
 6     private int empno;
 7     private String ename;
 8     private String job;
 9     private Date hiredate;
10     private float sal;
11     public int getEmpno() {
12         return empno;
13     }
14     public void setEmpno(int empno) {
15         this.empno = empno;
16     }
17     public String getEname() {
18         return ename;
19     }
20     public void setEname(String ename) {
21         this.ename = ename;
22     }
23     public String getJob() {
24         return job;
25     }
26     public void setJob(String job) {
27         this.job = job;
28     }
29     public Date getHiredate() {
30         return hiredate;
31     }
32     public void setHiredate(Date hiredate) {
33         this.hiredate = hiredate;
34     }
35     public float getSal() {
36         return sal;
37     }
38     public void setSal(float sal) {
39         this.sal = sal;
40     }
41     
42     
43 }

 1 package cn.mldn.lxh.dbc;
 2 
 3 import java.sql.Connection;
 4 import java.sql.DriverManager;
 5 
 6 public class DatabaseConnection {
 7     private static final String DBDRIVER = "com.mysql.jdbc.Driver";
 8     private static final String DBURL = "jdbc:mysql://localhost:3306/mldn";
 9     private static final String DBUSER = "root";
10     private static final String DBPASS = "xyzk123";
11     private Connection conn = null;
12     public DatabaseConnection() throws Exception{ 
13         try{
14             Class.forName(DBDRIVER);
15             this.conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS);
16         }catch(Exception e){
17             throw e;
18         }
19     }
20     public Connection getConnection(){
21         return this.conn;
22     }
23     public void close()throws Exception{
24         if(this.conn != null){
25             try{
26                 this.conn.close();
27             }catch(Exception e){
28                 throw e;
29             }
30         }
31     }
32 }

 1 package cn.mldn.lxh.dao;
 2 
 3 import java.util.List;
 4 
 5 import cn.mldn.lxh.vo.Emp;
 6 
 7 public interface IEmpDAO {
 8     
 9     public boolean doCreate(Emp emp) throws Exception;    //数据增加操作
10     
11     public List<Emp> findAll(String keyWord) throws Exception;    //查询全部数据
12     
13     public Emp findById(int empno) throws Exception;    //根据雇员编号查询雇员信息
14 }

 1 package cn.mldn.lxh.dao.impl;
 2 
 3 import java.sql.Connection;
 4 import java.sql.PreparedStatement;
 5 import java.sql.ResultSet;
 6 import java.util.ArrayList;
 7 import java.util.List;
 8 
 9 import cn.mldn.lxh.dao.IEmpDAO;
10 import cn.mldn.lxh.vo.Emp;
11 
12 public class EmpDAOImpl implements IEmpDAO {
13     private Connection conn = null;
14     private PreparedStatement pstmt = null;
15     public EmpDAOImpl(Connection conn){
16         this.conn = conn;
17     }
18     
19     public boolean doCreate(Emp emp) throws Exception {
20         boolean flag = false;
21         String sql = "INSERT INTO emp(empno,ename,job,hiredate,sal) VALUES(?,?,?,?,?)";
22         this.pstmt = this.conn.prepareStatement(sql);
23         this.pstmt.setInt(1, emp.getEmpno());
24         this.pstmt.setString(2, emp.getEname());
25         this.pstmt.setString(3, emp.getJob());
26         this.pstmt.setDate(4, new java.sql.Date(emp.getHiredate().getTime()));
27         this.pstmt.setFloat(5, emp.getSal());
28         if(this.pstmt.executeUpdate()>0){
29             flag = true;
30         }
31         this.pstmt.close();
32         return flag;
33     }
34     
35     public List<Emp> findAll(String keyWord) throws Exception {
36         List<Emp> all = new ArrayList<Emp>();
37         String sql = "SELECT empno,ename,job,hiredate,sal FROM emp WHERE ename LIKE ? OR job LIKE?";
38         this.pstmt = this.conn.prepareStatement(sql);
39         this.pstmt.setString(1, "%" + keyWord + "%");
40         this.pstmt.setString(2, "%" + keyWord + "%");
41         ResultSet rs = this.pstmt.executeQuery();
42         Emp emp = null;
43         while(rs.next()){
44             emp = new Emp();
45             emp.setEmpno(rs.getInt(1));
46             emp.setEname(rs.getString(2));
47             emp.setJob(rs.getString(3));
48             emp.setHiredate(rs.getDate(4));
49             emp.setSal(rs.getFloat(5));
50             all.add(emp);
51         }
52         this.pstmt.close();
53         return all;
54     }
55     
56     public Emp findById(int empno) throws Exception {
57         Emp emp = null;
58         String sql = "SELECT empno,ename,job,hiredate,sal FROM emp WHERE empno = ?";
59         this.pstmt = this.conn.prepareStatement(sql);
60         this.pstmt.setInt(1, empno);
61         ResultSet rs = this.pstmt.executeQuery();
62         if(rs.next()){
63             emp  = new Emp();
64             emp.setEmpno(rs.getInt(1));
65             emp.setEname(rs.getString(2));
66             emp.setJob(rs.getString(3));
67             emp.setHiredate(rs.getDate(4));
68             emp.setSal(rs.getFloat(5));
69         }
70         this.pstmt.close();
71         return emp;
72     }
73 }

 1 package cn.mldn.lxh.dao.proxy;
 2 
 3 import java.util.List;
 4 
 5 import cn.mldn.lxh.dao.IEmpDAO;
 6 import cn.mldn.lxh.dao.impl.EmpDAOImpl;
 7 import cn.mldn.lxh.dbc.DatabaseConnection;
 8 import cn.mldn.lxh.vo.Emp;
 9 
10 public class EmpDAOProxy implements IEmpDAO{
11     private DatabaseConnection dbc = null;
12     private IEmpDAO dao = null;
13     public EmpDAOProxy() throws Exception{
14         this.dbc = new DatabaseConnection();
15         this.dao = new EmpDAOImpl(this.dbc.getConnection());
16     }
17     public boolean doCreate(Emp emp) throws Exception{
18         boolean flag = false;
19         try{
20             if(this.dao.findById(emp.getEmpno()) == null){
21                 flag = this.dao.doCreate(emp);
22             }
23         }catch(Exception e){
24             throw e;
25         }finally{
26             this.dbc.close();
27         }
28         return flag;
29     }
30     public List<Emp> findAll(String keyWord) throws Exception {
31         List<Emp> all = null;
32         try{
33             all = this.dao.findAll(keyWord);
34             }catch(Exception e){
35                 throw e;
36             }finally{
37                 this.dbc.close();
38             }
39         return all;
40     }
41     public Emp findById(int empno) throws Exception {
42         Emp emp = null;
43         try{
44             emp = this.dao.findById(empno);
45         }catch(Exception e){
46             throw e;
47         }finally{
48             this.dbc.close();
49         }
50         return emp;
51     }
52 }

 1 package cn.mldn.lxh.factory;
 2 
 3 import cn.mldn.lxh.dao.IEmpDAO;
 4 import cn.mldn.lxh.dao.proxy.EmpDAOProxy;
 5 
 6 public class DAOFactory {
 7     public static IEmpDAO getIEmpDAOInstance()throws Exception{
 8         return new EmpDAOProxy();
 9     }
10 }

 1 <html xmlns="http://www.w3.org/1999/xhtml">
 2 <head>
 3 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 4 <title>Dao</title>
 5 </head>
 6 
 7 <body>
 8     <form action="emp_insert_do.jsp" method="post">
 9         编号：<input type="text" name="empno" /><br />
10         姓名：<input type="text" name="ename" /><br />
11         职位：<input type="text" name="job" /><br />
12         日期：<input type="text" name="hiredate" /><br />
13         工资：<input type="text" name="sal" /><br />
14         <input type="submit" value="注册" />
15         <input type="reset" value="重置" />
16     </form>
17 </body>
18 </html>

 1 <html xmlns="http://www.w3.org/1999/xhtml">
 2 <head>
 3 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 4 <title>peixun</title>
 5 </head>
 6 
 7 <body>
 8     <%
 9         Emp emp = new Emp();
10         emp.setEmpno(Integer.parseInt(request.getParameter("empno")));
11         emp.setEname(request.getParameter("ename"));
12         emp.setJob(request.getParameter("job"));
13         
14         emp.setHiredate(new SimpleDateFormat("yyyy-MM-dd").parse(request
15             .getParameter("hiredate")));
16         
17         emp.setSal(Float.parseFloat(request.getParameter("sal")));
18         try{
19             if(DAOFactory.getIEmpDAOInstance().doCreate(emp)){
20     %>
21                 <h3>信息添加成功</h3>
22     <%
23             }else{
24     %>
25                 <h3>信息添加失败</h3>
26     <%
27             }
28     
29         }catch(Exception e){
30             e.printStackTrace();
31         }
32     %>
33 </body>
34 </html>