DBConnection.java

package com.github.coolcooldee.sloth.source.db.mysql;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

/**
 * Created by sloth on 16/6/17.
 */
public class DBConnection {

    private static Connection conn;

    static String host = "127.0.0.1";
    static String port = "3306";
    static String schema = "test";
    static String driver = "com.mysql.jdbc.Driver";
    static String url = "jdbc:mysql://"+host+":"+port+"/"+schema;
    static String user;
    static String password;

    static boolean inited = false;

    private static String buildDBUrl(){
        return "jdbc:mysql://"+host+":"+port+"/"+schema;
    }

    public static void  init(String host, String port, String schema, String user, String password) {
        DBConnection.host = host;
        DBConnection.port = port;
        DBConnection.schema = schema;
        DBConnection.user = user;
        DBConnection.password = password;
        DBConnection.url = buildDBUrl();
        DBConnection.inited = true;
    }



    public static Connection getInstance() {
        if(!inited)
            throw new NullPointerException("please inti it beforce using getInstance ... ");
        try {
            if (conn == null || conn.isClosed()) {
                try {
                    Class.forName(DBConnection.driver);
                    try {
                        conn = DriverManager.getConnection(DBConnection.url, DBConnection.user, DBConnection.password);
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                } catch (ClassNotFoundException e) {
                    e.printStackTrace();
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
}