JDBC连接mysql

1.properties 配置文件

driver=com.mysql.jdbc.Driver
#url
url=jdbc:mysql://localhost:3306/pabitel
#user
user=root
#password
password=493656696

2.建一个用来获取连接的类

public class DBHelper {
    private DBHelper(){}
    private static String url;
    private static String driver;
    private static String user;
    private static String pwd;
    private static ThreadLocal<Connection> tl=new ThreadLocal<Connection>();
    static{
        try {
            Properties prop=new Properties();
            InputStream is=DBHelper.class.getClassLoader().getResourceAsStream("properties.properties");
            prop.load(is);
            driver=prop.getProperty("driver");
            user=prop.getProperty("user");
            pwd=prop.getProperty("password");
            url=prop.getProperty("url");
            Class.forName(driver);
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    public static Connection getConnection() throws SQLException{
        Connection conn=DriverManager.getConnection(url,user,pwd);
        tl.set(conn);
        return conn;
    }
    public static void closeConnection(){
        Connection conn=tl.get();
        if(conn!=null){
            try {
                conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            tl.remove();
        }
    }
}

3.threadlocal的使用

其类似于map，key-value组合，key为线程，value为connection

4.线程池的使用

定义线程池private static BasicDataSource ds;

后续在静态块中设置如下参数

　　　　　　　ds=new BasicDataSource();
            ds.setDriverClassName(prop.getProperty("driver"));
            ds.setUrl(prop.getProperty("url"));
            ds.setUsername(prop.getProperty("user"));
            ds.setPassword(prop.getProperty("psw"));
            ds.setInitialSize(Integer.parseInt(prop.getProperty("initsize")));
            ds.setMaxActive(Integer.parseInt(prop.getProperty("maxactive")));
            ds.setMaxWait(Integer.parseInt(prop.getProperty("maxwait")));
            ds.setMinIdle(Integer.parseInt(prop.getProperty("minidle")));
            ds.setMaxIdle(Integer.parseInt(prop.getProperty("maxidle")));

即可用线程池来获取连接。