1. Java数据库的连接及操作

1)数据库连接工具类

 1 /**
 2  * 数据库连接工具类
 3  * @author vanguard
 4  *
 5  */
 6 public class JDBCUtils {
 7     
 8     private static Connection conn;
 9     private static String driverClass;
10     private static String url;
11     private static String username;
12     private static String password;
13     private static InputStream in;
14     
15     static {
16         try {
17             in = JDBCUtils.class.getClassLoader().getResourceAsStream("database.properties");
18             Properties prop = new Properties();
19             prop.load(in);
20             driverClass = prop.getProperty("driverClass");
21             url = prop.getProperty("url");
22             username = prop.getProperty("username");
23             password = prop.getProperty("password");
24             Class.forName(driverClass);
25             conn = DriverManager.getConnection(url, username, password);
26         } catch (IOException e) {
27             System.out.println("加载配置文件失败");
28             e.printStackTrace();
29         } catch (ClassNotFoundException e) {
30             System.out.println("驱动包加载失败");
31             e.printStackTrace();
32         } catch (SQLException e) {
33             System.out.println("数据库连接失败");
34             e.printStackTrace();
35         }
36     }
37     
38     /**
39      * 获取连接的方法
40      * @return
41      */
42     public static Connection getConnection() {
43         return conn;
44     }
45     
46     /**
47      * 关闭连接 释放资源
48      * @param conn
49      * @param sm
50      * @throws SQLException
51      */
52     public static void close(Connection conn, PreparedStatement ps) throws SQLException {
53         if(conn != null) {
54             conn.close();
55         }
56         if(ps != null) {
57             ps.close();
58         }
59     }
60     
61     /**
62      * 关闭所有连接
63      * @param conn
64      * @param st
65      * @param rs
66      * @throws SQLException
67      */
68     public static void close(Connection conn, PreparedStatement ps, ResultSet rs) throws SQLException {
69         if(conn != null) {
70             conn.close();
71         }
72         if(ps != null) {
73             ps.close();
74         }
75         if(rs != null) {
76             rs.close();
77         }
78     } 
79     
80 }

2)JDBC读取数据表sort,每行数据封装到Sort类的对象中很多个Sort类对象,存储到List集合中

 1 package com.java.demo02;
 2 /**
 3  * sort实体类
 4  * @author vanguard
 5  *
 6  */
 7 public class Sort {
 8     private int sid;
 9     private String sname;
10     private String sprice;
11     private String sdesc;
12     
13     public Sort() {}
14     public Sort(int sid, String sname, String sprice, String sdesc) {
15         super();
16         this.sid = sid;
17         this.sname = sname;
18         this.sprice = sprice;
19         this.sdesc = sdesc;
20     }
21     public int getSid() {
22         return sid;
23     }
24     public void setSid(int sid) {
25         this.sid = sid;
26     }
27     public String getSname() {
28         return sname;
29     }
30     public void setSname(String sname) {
31         this.sname = sname;
32     }
33     public String getSprice() {
34         return sprice;
35     }
36     public void setSprice(String sprice) {
37         this.sprice = sprice;
38     }
39     public String getSdesc() {
40         return sdesc;
41     }
42     public void setSdesc(String sdesc) {
43         this.sdesc = sdesc;
44     }
45     
46     @Override
47     public String toString() {
48         return "Sort [sid=" + sid + ", sname=" + sname + ", sprice=" + sprice
49                 + ", sdesc=" + sdesc + "]";
50     }    
51 }