26.4.5. 作为JDBC驱动程序的一部分运行

MySQL Connector/J JDBC驱动程序的1个特点是,能够在JDBC连接字符串中将“SocketFactory”指定为参数。MySQL Connector/MXJ包含1个定制的SocketFactory。首次连接时,SocketFactory将部署并启动MySQL数据库。SocketFactory也会显示1个“shutdown”方法。

要想使用它,请在JDBC连接字符串上指定“socketFactory”参数,并将其值设为“com.mysql.management.driverlaunched.ServerLauncherSocketFactory”。

在下面的示例中,有1个能创建连接的程序,执行查询,并将结果输出到System.out。MySQL数据库将作为连接进程的组成部分予以部署并启动,最后是结束部分。

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import com.mysql.management.driverlaunched.ServerLauncherSocketFactory;

public class ConnectorMXJTestExample {
    public static void main(String[] args) throws Exception {
        String hostColonPort = "localhost:3336";
        
        String driver = com.mysql.jdbc.Driver.class.getName();
        String url = "jdbc:mysql://" + hostColonPort + "/" + "?"
                + "socketFactory="
                + ServerLauncherSocketFactory.class.getName();
        String userName = "root";
        String password = "";

        Class.forName(driver);
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(url, userName, password);
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT VERSION()");
            rs.next();
            String version = rs.getString(1);
            rs.close();
            stmt.close();

            System.out.println("------------------------");
            System.out.println(version);
            System.out.println("------------------------");
        } finally {
            try {
                conn.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
            ServerLauncherSocketFactory.shutdown(hostColonPort);
        }
    }
}
  

要想运行上述程序,在CLASSPATH中必须有connector-mxj.jar和Connector/J。然后键入:

java ConnectorMXJTestExample
  

当然,对于MySQL数据库,有很多可设置的选项。通过为每个服务器选项冠以前缀“server”,可将其作为JDBC连接字符串的部分,简单地指定这些选项。在下述示例中,我们设置了3个驱动程序参数和2个服务器参数:

        String url = "jdbc:mysql://" + hostColonPort + "/" 
                + "?"
                + "socketFactory="
                + ServerLauncherSocketFactory.class.getName();
                + "&"
                + "cacheServerConfiguration=true"
                + "&"
                + "useLocalSessionState=true"
                + "&"
                + "server.basedir=/opt/myapp/db"
                + "&"
                + "server.datadir=/mnt/bigdisk/myapp/data";
  
关注编程学问公众号