package com.goldmsg.filepusher.jetty;
/**
 * 連線資料庫的工具類,被定義成不可繼承且是私有訪問
 * Created by zhouhaiming on 2016/9/21.
 */
import com.mysql.jdbc.Statement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public final class 
 
DBUtils {
    private static String url = "jdbc:mysql://loacalhost:3306/apple";
    private static String user = "root";
    private static String psw = "1111111";

    private static  Connection conn;

    static {
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
 
            throw new RuntimeException(e);
        }
    }

    private DBUtils() {

    }

    /**
     * 獲取資料庫的連線
     * @return conn
     */
    public static Connection getConnection() {
        if(null == conn) {
            try {
                conn = DriverManager.getConnection(url, user, psw);
 
            } catch (SQLException e) {
                e.printStackTrace();
                throw new RuntimeException(e);
            }
        }
        return conn;
    }

    /**
     * 釋放資源
     * @param conn
     * @param pstmt
     * @param rs
     */
    public static void closeResources(Connection conn,PreparedStatement pstmt,ResultSet rs) {
        if(null != rs) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
                throw new RuntimeException(e);
            } finally {
                if(null != pstmt) {
                    try {
                        pstmt.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                        throw new RuntimeException(e);
                    } finally {
                        if(null != conn) {
                            try {
                                conn.close();
                            } catch (SQLException e) {
                                e.printStackTrace();
                                throw new RuntimeException(e);
                            }
                        }
                    }
                }
            }
        }
    }

    public static class MySQLDemo {

        // JDBC 驅動名及資料庫 URL
        static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
        static final String DB_URL = "jdbc:mysql://localhost:3306/store";

        // 資料庫的使用者名稱與密碼，需要根據自己的設定
        static final String USER = "root";
        static final String PASS = "123456";

        public static void main(String[] args) {
            com.mysql.jdbc.Connection conn = null;
            Statement stmt = null;
            try{
                // 註冊 JDBC 驅動
                Class.forName("com.mysql.jdbc.Driver");
                Class.forName(JDBC_DRIVER);

                // 開啟連結
                System.out.println("連線資料庫...");
                conn = (com.mysql.jdbc.Connection) DriverManager.getConnection(DB_URL,USER,PASS);

                // 執行查詢
                System.out.println(" 例項化Statement對...");
    //            stmt = (Statement) conn.createStatement();
                 stmt = (Statement) conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
                String sql;
                sql = "SELECT * FROM obj_replica_task WHERE task_status =0";
                ResultSet rs = stmt.executeQuery(sql);
                // 展開結果集資料庫
                while(rs.next()){
                    // 通過欄位檢索
                    String task_id=rs.getString("task_id");
                    String storage_id=rs.getString("storage_id");
                    // 輸出資料
                    System.out.println(task_id);
                    System.out.println(storage_id);
                }
                // 完成後關閉
                rs.close();
                stmt.close();
                conn.close();
            }catch(SQLException se){
                // 處理 JDBC 錯誤
                se.printStackTrace();
            }catch(Exception e){
                // 處理 Class.forName 錯誤
                e.printStackTrace();
            }finally{
                // 關閉資源
                try{
                    if(stmt!=null) stmt.close();
                }catch(SQLException se2){
                }// 什麼都不做
                try{
                    if(conn!=null) conn.close();
                }catch(SQLException se){
                    se.printStackTrace();
                }
            }
            System.out.println("Goodbye!");
        }
    }
}