package util;

import java.sql.*;
public final class DButil {

	private static final String driver = "com.mysql.jdbc.Driver";
	private static final String url = "jdbc:mysql://localhost:3306/runoob";
	private static final String user = "root";
	private static final String password = "123456";
	// 此方法為獲取資料庫連線
	public static Connection getConnection() {
		Connection conn = null;
		try {
			
			Class.forName(driver); // 載入資料庫驅動
			if (null == conn) {
				conn = DriverManager.getConnection(url, user, password);
			}
		} catch (ClassNotFoundException e) {
			System.out.println("Sorry,找不到驅動");
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		}
		return conn;
	}

	/**
	 * 
	 * 無引數增刪改【Add、Del、Update】
	 * 
	 * 
	 * 
	 * @param sql
	 * 
	 * @return int
	 */

	public static int executeNonQuery(String sql) {
		int result = 0;
		Connection conn = null;
		Statement stmt = null;
		try {
			conn = getConnection();
			stmt = conn.createStatement();
			result = stmt.executeUpdate(sql);
		} catch (SQLException err) {
			err.printStackTrace();
			free(null, stmt, conn);
		} finally {
			free(null, stmt, conn);
		}
		return result;
	}

	/**
	 * 
	 * 有引數增刪改【Add、Delete、Update】
	 * 
	 * 
	 * 
	 * @param sql
	 * 
	 * @param obj
	 * 
	 * @return int
	 */

	public static int executeNonQuery(String sql, Object... obj) {
		int result = 0;
		Connection conn = null;
		PreparedStatement pstmt = null;
		try {
			conn = getConnection();
			pstmt = conn.prepareStatement(sql);
			for (int i = 0; i < obj.length; i++) {
				pstmt.setObject(i + 1, obj[i]);
			}
			result = pstmt.executeUpdate();
		} catch (SQLException err) {
			err.printStackTrace();
			free(null, pstmt, conn);
		} finally {
			free(null, pstmt, conn);
		}
		return result;
	}

	/**
	 * 
	 * 無參查詢【Query】
	 * 
	 * 
	 * 
	 * @param sql
	 * 
	 * @return ResultSet
	 */

	public static ResultSet executeQuery(String sql) {
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		try {
			conn = getConnection();
			stmt = conn.createStatement();
			rs = stmt.executeQuery(sql);
		} catch (SQLException err) {
			err.printStackTrace();
			free(rs, stmt, conn);
		}
		return rs;
	}

	/**
	 * 
	 * 有參查詢【Query】
	 * 
	 * 
	 * 
	 * @param sql
	 * 
	 * @param obj
	 * 
	 * @return ResultSet
	 */

	public static ResultSet executeQuery(String sql, Object... obj) {
		Connection conn = null;
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		try {
			conn = getConnection();
			pstmt = conn.prepareStatement(sql);
			for (int i = 0; i < obj.length; i++) {
				pstmt.setObject(i + 1, obj[i]);
			}
			rs = pstmt.executeQuery();
		} catch (SQLException err) {
			err.printStackTrace();
			free(rs, pstmt, conn);
		}
		return rs;
	}

	/**
	 * 
	 * 判斷記錄是否存在
	 * 
	 * 
	 * 
	 * @param sql
	 * 
	 * @return Boolean
	 */

	public static Boolean isExist(String sql) {
		ResultSet rs = null;
		try {
			rs = executeQuery(sql);
			rs.last();
			int count = rs.getRow();
			if (count > 0) {
				return true;
			} else {
				return false;
			}
		} catch (SQLException err) {
			err.printStackTrace();
			free(rs);
			return false;
		} finally {
			free(rs);
		}
	}

	/**
	 * 
	 * 判斷記錄是否存在(帶引數)
	 * 
	 * 
	 * 
	 * @param sql
	 * 
	 * @return Boolean
	 */

	public static Boolean isExist(String sql, Object... obj) {
		ResultSet rs = null;
		try {
			rs = executeQuery(sql, obj);
			rs.last();
			int count = rs.getRow();
			if (count > 0) {
				return true;
			} else {
				return false;
			}
		} catch (SQLException err) {
			err.printStackTrace();
			free(rs);
			return false;
		} finally {
			free(rs);
		}
	}

	/**
	 * 
	 * 獲取查詢記錄的總行數
	 * 
	 * 
	 * 
	 * @param sql
	 * 
	 * @return int
	 */

	public static int getCount(String sql) {
		int result = 0;
		ResultSet rs = null;
		try {
			rs = executeQuery(sql);
			rs.last();
			result = rs.getRow();
		} catch (SQLException err) {
			free(rs);
			err.printStackTrace();
		} finally {
			free(rs);
		}
		return result;
	}

	/**
	 * 
	 * 獲取查詢記錄的總行數(帶引數)
	 * 
	 * 
	 * 
	 * @param sql
	 * 
	 * @param obj
	 * 
	 * @return int
	 */

	public static int getCount(String sql, Object... obj) {
		int result = 0;
		ResultSet rs = null;
		try {
			rs = executeQuery(sql, obj);
			rs.last();
			result = rs.getRow();
		} catch (SQLException err) {
			err.printStackTrace();
		} finally {
			free(rs);
		}
		return result;
	}

	/**
	 * 
	 * 釋放【ResultSet】資源
	 * 
	 * 
	 * 
	 * @param rs
	 */

	public static void free(ResultSet rs) {
		try {
			if (rs != null) {
				rs.close();
			}
		} catch (SQLException err) {
			err.printStackTrace();
		}

	}

	/**
	 * 
	 * 釋放【Statement】資源
	 * 
	 * 
	 * 
	 * @param st
	 */

	public static void free(Statement st) {
		try {
			if (st != null) {
				st.close();
			}
		} catch (SQLException err) {
			err.printStackTrace();
		}

	}

	/**
	 * 
	 * 釋放【Connection】資源
	 * 
	 * 
	 * 
	 * @param conn
	 */

	public static void free(Connection conn) {
		try {
			if (conn != null) {
				conn.close();
			}
		} catch (SQLException err) {
			err.printStackTrace();
		}

	}

	/**
	 * 
	 * 釋放所有資料資源
	 * 
	 * 
	 * 
	 * @param rs
	 * 
	 * @param st
	 * 
	 * @param conn
	 */

	public static void free(ResultSet rs, Statement st, Connection conn) {
		free(rs);
		free(st);
		free(conn);
	}

}