JDBC

java_JDBC

public abstract class DBCP_Utiles<T> {
    /**
     * 带有配置文件的DBCP的使用：
     * <p>
     * 核心类：BasicDataSourceFactory(工厂)
     * public static DataSource createDataSource(new FileInputStream("xxx.properties"));
     */

//	private static BasicDataSource ds=new BasicDataSource();

    private static BasicDataSource ds = null;

    static {
        Properties ps = new Properties();
        try {
            //直接获取流的方式：工程根目录
//			ps.load(new FileInputStream("dbcp.properties"));
            //类加载器获取配置文件：src目录
            ps.load(DBCP_Utiles01.class.getClassLoader().getResourceAsStream("dbcp.properties"));

            ds = (BasicDataSource) BasicDataSourceFactory.createDataSource(ps);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            throw new RuntimeException("加载错误");
        }
    }

    public static Connection getConnection() throws Exception {
        return ds.getConnection();
    }

    public static void closePoor(Connection conn, Statement st, ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                System.out.println(e);
            }
        }
        if (st != null) {
            try {
                st.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                System.out.println(e);
            }
        }
        if (st != null) {
            try {
                st.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                System.out.println(e);
            }
        }
    }
    //sql增删改
    public int exec_update(String sql, Object[] params) throws Exception {
        Connection connection = getConnection();
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
        for (int i = 0; i < params.length; i++) {
            preparedStatement.setObject((i + 1), params[i]);
        }
        int num = preparedStatement.executeUpdate();
        return num;
    }
    //sql查询
    public ArrayList<T> exec_query(String sql, Object[] params) throws Exception {
        ArrayList<T> list = new ArrayList();
        Connection connection = getConnection();
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
        if (params != null) {
            for (int i = 0; i < params.length; i++) {
                preparedStatement.setObject((i + 1), params[i]);
            }
        }
        ResultSet resultSet = preparedStatement.executeQuery();
        while (resultSet.next()) {
            T t = this.getBean(resultSet);
            list.add(t);
        }
        return list;
    }

    //获取bean
    public abstract T getBean(ResultSet rs) throws SQLException;
}