1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
import java.sql.*;
public class DBUtils {
//URL的填写请自行百度，根据数据库版本搜索
private final static String URL = "your url";
//填写你的数据库连接用户名
private final static String ROOT = "your name";
//填写你的数据库连接密码
private final static String PASSWORD = "your password";
private static Connection conn;
private static PreparedStatement ps;
private static ResultSet rs;
//加载驱动，获取连接
public static Connection getConn() throws SQLException, ClassNotFoundException {
Class.forName("com.mysql.jdbc.Driver");
return DriverManager.getConnection(URL, ROOT, PASSWORD);
}
/**
* @param sql：执行的sql
* @param params：设置参数
* @return
*/
//执行增删改语句，这里使用Object[]数组是为了满足不同参数传递的需要
public static boolean executeUpdate(String sql, Object[] params){
boolean flag = false;
try {
conn = getConn();
ps = conn.prepareStatement(sql);//预编译SQL
if (params != null) {
for (int i = 0; i < params.length; i++) {
ps.setObject(i + 1, params[i]);
}
}
int count = ps.executeUpdate();//执行SQL
if (count > 0)
flag = true;
else
flag = false;
return flag;
} catch (SQLException s) {
s.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return flag;
}
//执行查询语句
public static ResultSet executeQuery(String sql, Object[] params) {
try {
conn = getConn();
ps = conn.prepareStatement(sql);
if (params != null) {
for (int i = 0; i < params.length; i++) {
ps.setObject(i + 1, params[i]);
}
}
rs = ps.executeQuery();
return rs;
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException s) {
s.printStackTrace();
}
return rs;
}
//关闭流，由于参数个数不同，这里使用了重载
public static void close(Connection conn, PreparedStatement ps, ResultSet rs) {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (ps != null) {
try {
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void close(Connection conn, PreparedStatement ps) {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (ps != null) {
try {
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
//这里对代码进行测试，测试数据库是否连接成功，没有输出就是最好的消息
public static void main(String[] args) {
try {
DBUtils.getConn();
} catch (SQLException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}