初步完成了一个能连接不同版本mysql的DriverPool

ExperimentMultiTypeConnMultiTypeConn.java

import java.net.URL;
import java.net.URLClassLoader;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.SQLException;
import java.util.Arrays;
import java.util.Properties;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;

public class Test {

    private static ConcurrentHashMap<String, Class> driverClassCacheMap = new ConcurrentHashMap<>();

    private static Connection getConnection(Properties props, String... libs) throws InstantiationException, IllegalAccessException, SQLException {

        Class driverClass = driverClassCacheMap.computeIfAbsent(props.getProperty("driverType"), k -> {
            ClassLoader threadClassLoader = Thread.currentThread().getContextClassLoader();
            URL[] libUrls = Arrays.stream(libs)
                    .map(lib -> threadClassLoader.getClass().getResource(lib))
                    .toArray(URL[]::new);
            URLClassLoader classLoader = new URLClassLoader(libUrls, threadClassLoader);
            System.out.println("miss");
            try {
                return classLoader.loadClass(props.getProperty("driverClass"));
            } catch (ClassNotFoundException e) {
                return null;
            }
        });
        System.out.print(driverClassCacheMap.size());
        if (driverClass != null) {
            Driver driver = (Driver) driverClass.newInstance();
            return driver.connect(props.getProperty("url"), props);
        } else {
            return null;
        }
    }

    public static void main(String[] args) throws InterruptedException {
        final int N = 120;
        final CountDownLatch latch = new CountDownLatch(2 * N);
        Thread[] m5s = new Thread[N];
        Thread[] m8s = new Thread[N];
        for (int i = 0; i < N; i++) {
            m5s[i] = new Thread(() -> {
                try {
                    Properties props = new Properties();
                    props.setProperty("user", "root");
                    props.setProperty("password", "123");
                    props.setProperty("url", "jdbc:mysql://localhost:3305?autoReconnect=true&useSSL=false");
                    props.setProperty("driverClass", "com.mysql.jdbc.Driver");
                    props.setProperty("driverType", "mysql5.x");
                    Connection conn = getConnection(props,
                            "/lib/mysql5/mysql-connector-java-5.1.34.jar");
                    if (conn != null) {
                        System.out.println(conn.getMetaData().getDatabaseProductVersion());
                    }
                    latch.countDown();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            });

            m8s[i] = new Thread(() -> {
                try {
                    Properties props = new Properties();
                    props.setProperty("user", "root");
                    props.setProperty("password", "123");
                    props.setProperty("url", "jdbc:mysql://localhost:3308?autoReconnect=true&useSSL=false");
                    props.setProperty("driverClass", "com.mysql.cj.jdbc.Driver");
                    props.setProperty("driverType", "mysql8.x");
                    Connection conn = getConnection(props,
                            "/lib/mysql8/mysql-connector-java-8.0.11.jar",
                            "/lib/mysql8/protobug-java-2.6.0");
                    if (conn != null) {
                        System.out.println(conn.getMetaData().getDatabaseProductVersion());
                    }
                    latch.countDown();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            });
        }

        long startTime = System.nanoTime();
        for (int i = 0; i < N; i++) {
            m5s[i].start();
            m8s[i].start();
        }

        latch.await();

        System.out.println((System.nanoTime() - startTime) / 1000_000);

    }
}