抽取jdbc工具类JdbcUtil

url=jdbc:mysql:///demo
user=root
password=123
driver=com.mysql.jdbc.Driver

public class JdbcUtil {
    private static Connection con = null;
    private static String url;
    private static String user;
    private static String password;
    private static String driver;
    static{
        Properties p = new Properties();//创建Properties集合对象
        InputStream res = JdbcUtil.class  //利用类加载器获取到该配置文件，他的默认路径是从src下寻找，返回一个输入流
                .getClassLoader()
                .getResourceAsStream("jdbc.properties");
        try {
            p.load(res);  //加载配置文件
            url = p.getProperty("url"); //获取配置文件中的值
            user = p.getProperty("user");
            password = p.getProperty("password");
            driver = p.getProperty("driver");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取连接
     * @return
     */
    public static Connection getConnection(){
        try {
            Class.forName(driver);
            con = DriverManager.getConnection(url, user, password);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return con;
    }

    /**
     * 关闭连接
     * @param stmt
     * @param con
     */
    public static void close(Statement stmt,Connection con){
        if(stmt!=null){
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(con!=null){
            try {
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}