DAO设计模式例子
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1 <!-- 輸入界面 --> 2 <%@page contentType="text/html" pageEncoding="GBK"%> 3 <html> 4 <head> 5 </head> 6 <% request.setCharacterEncoding("GBK"); //解決亂碼問題 %> 7 8 9 <body> 10 <form action="emp_insert_do.jsp" method="post"> 11 empno:<input type="text" name="empno"><br> 12 13 ename:<input type="text" name="ename"><br> 14 15 job: <input type="text" name="job"><br> 16 17 hiredate: <input type="text" name="hiredate"><br> 18 19 sal: <input type="text" name="sal"><br> 20 21 22 <input type="submit" value = "submit"> 23 <input type="reset" value = "reset"> 24 </form> 25 </body> 26 </html>?
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1 <!-- 后臺插入數(shù)據(jù) --> 2 <%@page import="info.haowei.Dao.factory.DAOFactory"%> 3 <%@page import="java.text.SimpleDateFormat"%> 4 <%@page import="info.haowei.Dao.vo.Emp"%> 5 <%@page contentType="text/html" pageEncoding="GBK"%> 6 <html> 7 <head> 8 </head> 9 <% request.setCharacterEncoding("GBK"); //解決亂碼問題 %> 10 11 12 <body> 13 <% 14 Emp emp = new Emp(); 15 emp.setEmpno(Integer.parseInt(request.getParameter("empno"))); 16 emp.setEname(request.getParameter("ename")); 17 emp.setJob(request.getParameter("job")); 18 19 emp.setHiredate((new SimpleDateFormat("yyyy-MM-dd")).parse(request.getParameter("hiredate"))); 20 emp.setSal(Float.parseFloat(request.getParameter("sal"))); 21 22 try{ 23 24 if(DAOFactory.getIEmpDAOInstance().doCreate(emp)){ 25 26 27 28 %> 29 30 <h3>添加成功!!</h3> 31 32 <% 33 }else{ 34 %> 35 <h3>添加失敗!!!</h3> 36 <% 37 } 38 }catch(Exception e){ 39 e.printStackTrace(); 40 } 41 %> 42 43 </body> 44 </html>?
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1 //vo類 2 package info.haowei.Dao.vo; 3 4 import java.util.Date; 5 6 public class Emp { 7 8 private int empno; 9 private String ename; 10 private String job; 11 private Date hiredate; 12 private float sal; 13 14 public int getEmpno() { 15 return empno; 16 } 17 public void setEmpno(int empno) { 18 this.empno = empno; 19 } 20 public String getEname() { 21 return ename; 22 } 23 public void setEname(String ename) { 24 this.ename = ename; 25 } 26 public String getJob() { 27 return job; 28 } 29 public void setJob(String job) { 30 this.job = job; 31 } 32 public Date getHiredate() { 33 return hiredate; 34 } 35 public void setHiredate(Date hiredate) { 36 this.hiredate = hiredate; 37 } 38 public float getSal() { 39 return sal; 40 } 41 public void setSal(float sal) { 42 this.sal = sal; 43 } 44 45 }?
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1 //工廠類 2 package info.haowei.Dao.factory; 3 4 import info.haowei.Dao.dao.IEmpDAO; 5 import info.haowei.Dao.dao.proxy.EmpDAOProxy; 6 7 public class DAOFactory { 8 9 public static IEmpDAO getIEmpDAOInstance(){ 10 return new EmpDAOProxy(); 11 } 12 }?
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1 //操作數(shù)據(jù)庫的類 2 package info.haowei.Dao.dbc; 3 4 import java.sql.Connection; 5 import java.sql.DriverManager; 6 import java.sql.SQLException; 7 8 public class DatabaseConnection { 9 10 private static final String DBDRIVER = "org.gjt.mm.mysql.Driver"; 11 public static final String DBURL = "jdbc:mysql://localhost:3306/zhw"; 12 public static final String DBUSER = "root"; 13 public static final String DBPASS = "root"; 14 private Connection conn; 15 16 public DatabaseConnection() { 17 try { 18 Class.forName(DBDRIVER); 19 this.conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS); 20 } catch (ClassNotFoundException e) { 21 e.printStackTrace(); 22 } catch (SQLException e) { 23 e.printStackTrace(); 24 } 25 } 26 27 public Connection getConnection() { 28 return this.conn; 29 } 30 31 public void close() { 32 if (this.conn != null) { 33 try { 34 this.conn.close(); 35 } catch (SQLException e) { 36 e.printStackTrace(); 37 } 38 } 39 } 40 41 }?
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1 //代理類.相當于回調(diào)吧 2 package info.haowei.Dao.dao.proxy; 3 4 import java.util.List; 5 6 import info.haowei.Dao.dao.IEmpDAO; 7 import info.haowei.Dao.dao.impl.EmpDAOImpl; 8 import info.haowei.Dao.dbc.DatabaseConnection; 9 import info.haowei.Dao.vo.Emp; 10 11 //代理 12 public class EmpDAOProxy implements IEmpDAO { 13 14 private DatabaseConnection dbc = null; 15 private IEmpDAO dao = null; 16 17 public EmpDAOProxy() { 18 this.dbc = new DatabaseConnection(); 19 this.dao = new EmpDAOImpl(this.dbc.getConnection()); 20 } 21 22 public boolean doCreate(Emp emp) { 23 boolean flag = false; 24 try { 25 if(this.dao.findById(emp.getEmpno())==null){ 26 flag = this.dao.doCreate(emp); 27 } 28 29 } catch (Exception e) { 30 31 } finally { 32 dbc.close(); 33 } 34 35 return flag; 36 } 37 38 public List<Emp> findAll(String keyword) { 39 List<Emp>all = null; 40 try { 41 all = this.dao.findAll(keyword); 42 } catch (Exception e) { 43 44 } finally { 45 dbc.close(); 46 } 47 return all; 48 } 49 50 public Emp findById(int empno) { 51 Emp emp = null; 52 try { 53 emp = this.dao.findById(empno); 54 } catch (Exception e) { 55 56 } finally { 57 dbc.close(); 58 } 59 return emp; 60 } 61 }?
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1 //接口實現(xiàn)類,具體操作封裝類 2 package info.haowei.Dao.dao.impl; 3 4 import java.sql.Connection; 5 import java.sql.PreparedStatement; 6 import java.sql.ResultSet; 7 import java.sql.SQLException; 8 import java.util.ArrayList; 9 import java.util.List; 10 11 import javax.swing.text.html.HTMLDocument.HTMLReader.PreAction; 12 13 import info.haowei.Dao.dao.IEmpDAO; 14 import info.haowei.Dao.vo.Emp; 15 16 public class EmpDAOImpl implements IEmpDAO{ 17 18 19 private Connection conn = null; 20 private PreparedStatement pstmt = null; 21 public EmpDAOImpl(Connection conn){ 22 this.conn = conn; 23 } 24 25 26 27 28 29 30 public boolean doCreate(Emp emp) { 31 32 boolean flag = false; 33 String sql = "Insert into emp (empno,ename,job,hiredate,sal)Values(?,?,?,?,?)"; 34 35 try { 36 this.pstmt = this.conn.prepareStatement(sql); 37 this.pstmt.setInt(1,emp.getEmpno()); 38 this.pstmt.setString(2, emp.getEname()); 39 this.pstmt.setString(3, emp.getJob()); 40 this.pstmt.setDate(4, new java.sql.Date(emp.getHiredate().getTime())); 41 this.pstmt.setFloat(5, emp.getSal()); 42 if(this.pstmt.executeUpdate()>0){//如果存在更新 43 flag = true; 44 } 45 this.pstmt.close(); 46 } catch (SQLException e) { 47 e.printStackTrace(); 48 } 49 return flag; 50 } 51 52 public List<Emp> findAll(String keyword) { 53 List<Emp>all = new ArrayList<Emp>(); 54 String sql = "select empno,ename,job,hiredate,sal from emp where ename like ? or job like ?"; 55 try { 56 this.pstmt = this.conn.prepareStatement(sql); 57 this.pstmt.setString(1,"%"+keyword+"%"); 58 this.pstmt.setString(2,"%"+keyword+"%"); 59 ResultSet rs = this.pstmt.executeQuery(); 60 Emp emp = null; 61 while(rs.next()){ 62 emp = new Emp(); 63 emp.setEmpno(rs.getInt(1)); 64 emp.setEname(rs.getString(2)); 65 emp.setJob(rs.getString(3)); 66 emp.setHiredate(rs.getDate(4)); 67 emp.setSal(rs.getFloat(5)); 68 all.add(emp); 69 } 70 71 this.pstmt.close(); 72 } catch (SQLException e) { 73 e.printStackTrace(); 74 } 75 return all; 76 77 78 } 79 80 public Emp findById(int empno) { 81 Emp emp = null; 82 String sql = "select empno,ename,job,hiredate,sal from emp where empno=?"; 83 try { 84 this.pstmt = this.conn.prepareStatement(sql); 85 this.pstmt.setInt(1, empno); 86 ResultSet rs = this.pstmt.executeQuery(); 87 if(rs.next()){ 88 emp = new Emp(); 89 emp.setEmpno(rs.getInt(1)); 90 emp.setEname(rs.getString(2)); 91 emp.setJob(rs.getString(3)); 92 emp.setHiredate(rs.getDate(4)); 93 emp.setSal(rs.getFloat(5)); 94 } 95 this.pstmt.close(); 96 } catch (SQLException e) { 97 e.printStackTrace(); 98 } 99 return emp; 100 } 101 102 103 }?
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1 //操作接口 2 package info.haowei.Dao.dao; 3 4 import java.util.List; 5 6 import info.haowei.Dao.vo.Emp; 7 8 public interface IEmpDAO { 9 10 public boolean doCreate(Emp emp); 11 public List<Emp>findAll(String keyword); 12 public Emp findById(int empno); 13 14 }?
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1 //主函數(shù)類 2 3 package info.haowei.Dao.test; 4 5 import java.util.Date; 6 import java.util.Iterator; 7 import java.util.List; 8 9 import info.haowei.Dao.factory.DAOFactory; 10 import info.haowei.Dao.vo.Emp; 11 12 public class DAOTest { 13 14 public static void main(String[] args) { 15 16 /* 17 * 插入 18 Emp emp = null; 19 for(int x = 0 ; x< 5; x++ ){ 20 emp = new Emp(); 21 emp.setEmpno(1000+x); 22 emp.setEname("zhw"+x); 23 emp.setJob("coding" +x); 24 emp.setHiredate(new Date()); 25 emp.setSal(500+x); 26 DAOFactory.getIEmpDAOInstance().doCreate(emp); 27 28 } 29 30 */ 31 32 List<Emp>all = DAOFactory.getIEmpDAOInstance().findAll(""); 33 Iterator<Emp>iter = all.iterator(); 34 while(iter.hasNext()){ 35 36 Emp emp = iter.next(); 37 System.out.println(emp.getEmpno()+" "+emp.getEname()); 38 } 39 40 41 } 42 43 }總結(jié)
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