为什么HikariCP并不总是比其他jdbc连接池快？

如何解决为什么HikariCP并不总是比其他jdbc连接池快？

我在多个地方都读到，像在

这样的图表中可以看到，hikaricp的性能要比其他地方好，因此，我试图创建一个小的PoC来观察这种差异，并且我创建了以下代码：

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

import org.apache.commons.dbcp2.BasicDataSource;
import org.h2.jdbcx.JdbcConnectionPool;
import org.h2.jdbcx.JdbcDataSource;

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;

public class DbConnectionComparator {


    public static void main(String[] args) throws SQLException,FileNotFoundException {

        System.out.println("Using DriverManager");
        long startTime = System.currentTimeMillis();
        for (int i = 0; i < 1000; i++) {
            Connection connection = DriverManager.getConnection("jdbc:h2:~/test");
            connection.close();
        }

        System.out.printf("Results %d ms \n ",System.currentTimeMillis() - startTime);

        System.out.println("\nUsing JdbcDatasource");

        startTime = System.currentTimeMillis();
        JdbcDataSource datasource = new JdbcDataSource();
        datasource.setUrl("jdbc:h2:~/test");

        for (int i = 0; i < 1000; i++) {
            Connection connection4 = datasource.getConnection();
            connection4.close();
        }
        System.out.printf("Results %d ms\n",System.currentTimeMillis() - startTime);

        System.out.println("\nUsing Connection Pool");

        startTime = System.currentTimeMillis();
        JdbcConnectionPool connectionPool = JdbcConnectionPool.create("jdbc:h2:~/test","","");

        for (int i = 0; i < 1000; i++) {
            Connection connection8 = connectionPool.getConnection();
            connection8.close();
        }

        System.out.printf("Results %d ms \n",System.currentTimeMillis() - startTime);

        System.out.println("\nUsing Hikari pool");

        startTime = System.currentTimeMillis();
        HikariConfig config = new HikariConfig();

        config.setJdbcUrl("jdbc:h2:~/test");
        config.setUsername("");
        config.setPassword("");
        config.addDataSourceProperty("cachePrepStmts","true");
        config.addDataSourceProperty("prepStmtCacheSize","250");
        config.addDataSourceProperty("prepStmtCacheSqlLimit","2048");
        HikariDataSource hikariDatasource = new HikariDataSource(config);

        for (int i = 0; i < 1000; i++) {
            Connection connection4 = hikariDatasource.getConnection();
            connection4.close();
        }
        System.out.printf("Results %d ms\n",System.currentTimeMillis() - startTime);
        hikariDatasource.close();

        System.out.println("\nUsing DBCP pool");

        startTime = System.currentTimeMillis();
        BasicDataSource dbcpDatasource = new BasicDataSource();
        dbcpDatasource.setUrl("jdbc:h2:~/test");
        dbcpDatasource.setUsername("");
        dbcpDatasource.setPassword("");
        
        for (int i = 0; i < 1000; i++) {
            Connection connection5 = dbcpDatasource.getConnection();
            connection5.close();
        }
        System.out.printf("Results %d ms\n",System.currentTimeMillis() - startTime);
        dbcpDatasource.close();
    }
}

我正在使用H2，它具有以下依赖性：

<dependencies>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-simple</artifactId>
        <version>1.6.1</version>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <version>1.4.200</version>
    </dependency>
    <dependency>
        <groupId>com.github.javafaker</groupId>
        <artifactId>javafaker</artifactId>
        <version>1.0.2</version>
    </dependency>
    <dependency>
        <groupId>com.zaxxer</groupId>
        <artifactId>HikariCP</artifactId>
        <version>3.4.5</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-dbcp2</artifactId>
        <version>2.7.0</version>
    </dependency>
</dependencies>

我得到以下结果：

Using DriverManager
Results 4224 ms 
 
Using JdbcDatasource
Results 2752 ms

Using Connection Pool
Results 23 ms 

Using Hikari pool
Results 86 ms

Using DBCP pool
Results 83 ms

与DriverManager和JdbcDataSource相比，我看到了重大改进，但在JdbcConnectionPool和BasicDataSource上，我看到了更好的行为。

我做错什么了吗？我使用的是默认配置。

谢谢