java/Jdbc.java

package flowershop.daoimpl;


import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

public class Jdbc {
    // 数据连接URL
    static String url;
    // 创建Properties对象
    static Properties info = new Properties();

    // 静态代码块
    static {
        // 获取属性文件的输入流
        InputStream input = Jdbc.class.getClassLoader().getResourceAsStream("config.properties");

        try {
            if (input == null) {
                throw new NullPointerException("配置文件未找到");
            }

            // 加载属性文件
            info.load(input);

            // 从属性文件中读取url
            url = info.getProperty("url");

            // 从属性文件中读取driver
            String driverClassName = info.getProperty("driver");

            // 加载驱动程序
            Class.forName(driverClassName);
            System.out.println("驱动程序加载成功...");

        } catch (ClassNotFoundException e) {
            System.out.println("驱动程序加载失败...");
            e.printStackTrace();
        } catch (IOException e) {
            System.out.println("属性文件加载失败...");
            e.printStackTrace();
        } catch (NullPointerException e) {
            System.out.println(e.getMessage());
        }
    }

    // 创建数据连接
    public static Connection getConnection() throws SQLException {
        // 创建数据连接
        Connection conn = DriverManager.getConnection(url, info);
        return conn;
    }

    // 关闭连接方法
    public static void close(ResultSet rs, PreparedStatement pstmt, Connection conn) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (pstmt != null) {
            try {
                pstmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}