public static DBManager createInstance() {
if (per == null) {
per = new DBManager();
per.initDB();
}
return per;
}
// 加载驱动
public void initDB() {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (Exception e) {
e.printStackTrace();
}
}
// 连接数据库,获取句柄+对象
public void connectDB() {
System.out.println("Connecting to database...");
try {
conn = DriverManager.getConnection(URL, USER, PASS);
stmt = conn.createStatement();
} catch (SQLException e) {
e.printStackTrace();
}
System.out.println("SqlManager:Connect to database successful.");
}
// 关闭数据库 关闭对象,释放句柄
public void closeDB() {
System.out.println("Close connection to database..");
try {
stmt.close();
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
System.out.println("Close connection successful");
}
// 查询
public ResultSet executeQuery(String sql) {
ResultSet rs = null;
try {
rs = stmt.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
// 增添/删除/修改
public int executeUpdate(String sql) {
int ret = 0;
try {
ret = stmt.executeUpdate(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return ret;
}
}
2.登录
客户端提交过来一个用户名,一个密码,jsp连接数据库查询,如果两者都符合,返回登录成功信息,否则返回登录失败信
息。(我这里用权限来代表,当权限>-1即为登录成功)。
3.注册
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