通过properties配置文件连接数据库

/**
 * @作者：Jcuckoo
 * @日期：2008-11-8
 * @版本：V 1.0
 */

db.properties

1. DBDriver=sun.jdbc.odbc.JdbcOdbcDriver
2. Connection=jdbc:odbc:login
3. User=Jcuckoo
4. Password=

dbPool.java

1. import java.io.*;
2. import java.util.*;
3. import java.sql.*;
5. public class dbPool{
6.     private static dbPool instance = null;
8.     //取得连接
9.     public static synchronized Connection getConnection() {
10.         if (instance == null){
11.             instance = new dbPool();
12.         }
13.         return instance._getConnection();
14.     }
16.     private dbPool(){
17.         super();
18.     }
20.     private  Connection _getConnection(){
21.         try{
22.             String sDBDriver  = null;
23.             String sConnection   = null;
24.             String sUser = null;
25.             String sPassword = null;
27.             Properties p = new Properties();
28.             InputStream is = getClass().getResourceAsStream("/db.properties");
29.             p.load(is);
30.             sDBDriver = p.getProperty("DBDriver",sDBDriver);
31.             sConnection = p.getProperty("Connection",sConnection);
32.             sUser = p.getProperty("User","");
33.             sPassword = p.getProperty("Password","");
35.             Properties pr = new Properties();
36.             pr.put("user",sUser);
37.             pr.put("password",sPassword);
38.             pr.put("characterEncoding", "GB2312");
39.             pr.put("useUnicode", "TRUE");
41.             Class.forName(sDBDriver).newInstance();
42.             return DriverManager.getConnection(sConnection,pr);
43.         }
44.         catch(Exception se){
45.             System.out.println(se);
46.             return null;
47.         }
48.     }
50.     //释放资源
51.     public static void dbClose(Connection conn,PreparedStatement ps,ResultSet rs)
52.     throws SQLException
53.     {
54.           rs.close();
55.           ps.close();
56.           conn.close();
58.       }
59.     }

StudentDAO.java

1. public class StudentDAO {
2.     public StudentDAO() {
3.     }
4.     Connection conn;
5.     Statement st;
6.     ResultSet rs;
7.     public boolean checkLogin(String userName,String userPwd){
8.         String sql="select * from student where userName='"+userName+"' and userPwd='"+userPwd+"'";
9.         
10.         try {
11.             conn=dbPool.getConnection();
12.             st=conn.createStatement();
13.             rs=st.executeQuery(sql);
14.             if(rs.next()){
15.                 conn.close();
16.                 return true;
17.             }else{
18.                 conn.close();
19.                 return false;
20.             }
21.         } catch (SQLException e) {
22.             try {
23.                 conn.close();
24.             } catch (SQLException e1) {
25.                 e1.printStackTrace();
26.             }
27.             e.printStackTrace();
28.             return false;
29.         }
30.     }
31.     public boolean checkLogin(StudentForm student){
32.         String sql="select * from student where userName='"+student.getUserName()+"' and userPwd='"+student.getUserPwd()+"'";
33.         
34.         try {
35.             conn=dbPool.getConnection();
36.             st=conn.createStatement();
37.             rs=st.executeQuery(sql);
38.             if(rs.next()){
39.                 conn.close();
40.                 return true;
41.             }else{
42.                 conn.close();
43.                 return false;
44.             }
45.         } catch (SQLException e) {
46.             try {
47.                 conn.close();
48.             } catch (SQLException e1) {
49.                 e1.printStackTrace();
50.             }
51.             e.printStackTrace();
52.             return false;
53.         }
54.     }
56.     public List getAllStudent(){
57.         String sql="select * from student ";
58.         List students=new ArrayList();
59.         try {
60.             conn=dbPool.getConnection();
61.             st=conn.createStatement();
62.             rs=st.executeQuery(sql);
63.             while(rs.next()){
64.                 Student student=new Student(rs.getString("xuehao"),
65.                         rs.getString("userName"),
66.                         rs.getString("userPwd"),
67.                         rs.getInt("czxt"),
68.                         rs.getInt("wjyl"),
69.                         rs.getInt("sjjg")
70.                 );
71.                 students.add(student);
72.             }
73.             
74.         } catch (SQLException e) {
75.             try {
76.                 conn.close();
77.             } catch (SQLException e1) {
78.                 e1.printStackTrace();
79.             }
80.             e.printStackTrace();
81.             return null;
82.         }
83.         return students;
84.         
85.     }
86.     
87.     public Student getStudentByXuehao(String xuehao){
88.         String sql="select * from student where xuehao='"+xuehao+"'";
89.         Student student=null;
90.         try {
91.             conn=dbPool.getConnection();
92.             st=conn.createStatement();
93.             rs=st.executeQuery(sql);
94.             if(rs.next()){
95.                 student=new Student(rs.getString("xuehao"),
96.                         rs.getString("userName"),
97.                         rs.getString("userPwd"),
98.                         rs.getInt("czxt"),
99.                         rs.getInt("wjyl"),
100.                         rs.getInt("sjjg")
101.                 );
102.             }
103.             return student;
104.             
105.         } catch (SQLException e) {
106.             try {
107.                 conn.close();
108.             } catch (SQLException e1) {
109.                 e1.printStackTrace();
110.             }
111.             e.printStackTrace();
112.             return null;
113.         }
114.     }
115.     public boolean deleteStudent(String xuehao){
116.         String sql="delete from student where xuehao='"+xuehao+"'";
117.         conn=dbPool.getConnection();
118.         try {
119.             st=conn.createStatement();
120.             st.execute(sql);
121.             conn.close();
122.             return true;
123.         } catch (SQLException e) {
124.             e.printStackTrace();
125.             try {
126.                 conn.close();
127.             } catch (SQLException e1) {
128.                 e1.printStackTrace();
129.             }
130.             return false;
131.         }
132.     }
133.     public boolean updateStudent(Student student){
134.         String sql="update student set userName='" +student.getUserName()+
135.                 "',userPwd='" +student.getUserPwd()+"',czxt="+student.getCzxt()+
136.                 ",wjyl="+student.getWjyl()+",sjjg="+student.getSjjg()+" where xuehao='"+student.getXuehao()+"'";
137.         conn=dbPool.getConnection();
138.         try {
139.             st=conn.createStatement();
140.             st.execute(sql);
141.             conn.close();
142.             return true;
143.         } catch (SQLException e) {
144.             e.printStackTrace();
145.             try {
146.                 conn.close();
147.             } catch (SQLException e1) {
148.                 e1.printStackTrace();
149.             }
150.             return false;
151.         }
152.     }
153.     public boolean insertStudent(Student student){
154.         String sql="insert into student values('"+student.getXuehao()+"','" +student.getUserName()+
155.                 "','" +student.getUserPwd()+"',"+student.getCzxt()+
156.                 ","+student.getWjyl()+","+student.getSjjg()+")";
157.         //System.out.println(sql);
158.         conn=dbPool.getConnection();
159.         try {
160.             st=conn.createStatement();
161.             st.execute(sql);
162.             conn.close();
163.             return true;
164.         } catch (SQLException e) {
165.             e.printStackTrace();
166.             try {
167.                 conn.close();
168.             } catch (SQLException e1) {
169.                 e1.printStackTrace();
170.             }
171.             return false;
172.         }
173.     }
174. }