データベースに接続するDBUtilsツールクラス

1825 ワード

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;



public class DBUtils {

	static{

		try {

			Class.forName("oracle.jdbc.driver.OracleDriver");

		} catch (ClassNotFoundException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}

	public static Connection getConnection() throws SQLException{

		String url = "jdbc:oracle:thin:@10.25.116.138:1521:orcl";

		Connection conn = DriverManager.getConnection(url, "scott", "tiger");

		return conn;

	}

	public static void close(PreparedStatement ps){

		if(ps != null){

			try {

				ps.close();

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

		}

	}

	public static void close(ResultSet rs){

		if(rs != null){

			try {

				rs.close();

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

		}

	}

	public static void close(Connection conn){

		if(conn != null){

			try {

				conn.close();

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

		}

	}

	

	public static void main(String[] args) {

		

		String answer = "";

		try {

			Connection conn = DBUtils.getConnection();

			StringBuilder sql = new StringBuilder("select name from t_emp");

			PreparedStatement ps = conn.prepareStatement(sql.toString());

			ResultSet rs = ps.executeQuery();

			while (rs.next()) {

				answer += rs.getString("name");

			}

		} catch (SQLException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

		System.out.println("answer = " + answer);

	}

}