JavaWeb基礎工具類——BaseDao，javawebbasedao

JavaWeb基礎工具類——BaseDao，javawebbasedao

 1 package dao;
 2 
 3 import java.sql.Connection;
 4 import java.sql.DriverManager;
 5 import java.sql.PreparedStatement;
 6 import java.sql.ResultSet;
 7 import java.sql.SQLException;
 8 import java.sql.Statement;
 9 
10 public class BaseDao {
11     private static String URL = "jdbc:sqlserver://localhost:1433;DatabaseName=StudentManageSys";
12     private static String USER = "sa";
13     private static String PWD = "sa";
14     protected Connection conn = null;
15     protected PreparedStatement pstmt = null;
16 
17     static {
18         try {
19             Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
20         } catch (ClassNotFoundException e) {
21             e.printStackTrace();
22         }
23     }
24 
25     protected Connection getConnection() {
26         try {
27             return conn == null ? DriverManager.getConnection(URL, USER, PWD) : conn;
28         } catch (SQLException e) {
29             e.printStackTrace();
30             return null;
31         }
32     }
33 
34     protected void closeAll(Connection conn, Statement stmt, ResultSet rs) {
35         try {
36             if (conn != null)
37                 conn.close();
38             if (stmt != null)
39                 stmt.close();
40             if (rs != null)
41                 rs.close();
42         } catch (SQLException e) {
43             e.printStackTrace();
44         }
45     }
46 
47     protected Object execute(String sql, Object... objs) {
48         handle(sql, objs);
49         try {
50             boolean flag = pstmt.execute();
51             return flag ? pstmt.getResultSet() : pstmt.getUpdateCount();
52         } catch (SQLException e) {
53             e.printStackTrace();
54             return null;
55         }
56     }
57 
58     private void handle(String sql, Object[] objs) {
59         conn = getConnection();
60         try {
61             pstmt = conn.prepareStatement(sql);
62             if (objs != null) {
63                 for (int i = 0; i < objs.length; i++) {
64                     pstmt.setObject(i + 1, objs[i]);
65                 }
66             }
67         } catch (SQLException e) {
68             e.printStackTrace();
69         }
70     }
71 }

上第二學期學Servlet的時候寫的簡單的工具類，畢業了之後又改進了一下，技術還處於菜鳥級別，也只能改成這樣了，祝我天天進步！