如何解决：使用池时出现“找不到适用于jdbc：mysql：// localhost / dbname的驱动程序”错误？[重复]

Question

这个问题已经在这里有了答案 ：

臭名昭著的java.sql.SQLException：未找到合适的驱动程序 （13个答案）

3年前关闭。

我试图建立与数据库的连接，当我使用main方法测试代码时，它可以无缝运行。但是，当尝试通过Tomcat 7访问它时，它失败并显示以下错误：

No suitable driver found for jdbc:mysql://localhost/dbname.

我正在使用池。我将WEB-INF /
lib和.classpath中的mysql连接器（5.1.15），dbcp（1.4）和pool（1.4.5）库放入其中。我正在使用Eclipse
IDE。我的数据库驱动程序代码是：

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

import org.apache.tomcat.dbcp.dbcp.ConnectionFactory;
import org.apache.tomcat.dbcp.dbcp.DriverManagerConnectionFactory;
import org.apache.tomcat.dbcp.dbcp.PoolableConnectionFactory;
import org.apache.tomcat.dbcp.dbcp.PoolingDriver;
import org.apache.tomcat.dbcp.pool.impl.GenericObjectPool;

public class DatabaseConnector {
    public static String DB_URI = "jdbc:mysql://localhost/dbname";
    public static String DB_USER = "test";
    public static String DB_PASS = "password";

    // Singleton instance
    protected static DatabaseConnector _instance;

    protected String _uri;
    protected String _username;
    protected String _password;

    /**
     * Singleton, so no public constructor
     */
    protected DatabaseConnector(String uri, String username, String password) {
        _uri = uri;
        _username = username;
        _password = password;

        GenericObjectPool connectionPool = new GenericObjectPool(null);
        ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(
            _uri, _username, _password);
        PoolableConnectionFactory poolableConnectionFactory =
            new PoolableConnectionFactory(connectionFactory, connectionPool,
                                            null, null, false, true);
        PoolingDriver driver = new PoolingDriver();
        driver.registerPool("test", connectionPool);
    }

    /**
     * Returns the singleton instance
     */
    public static DatabaseConnector getInstance() {
        if (_instance == null) {
            _instance = new DatabaseConnector(DB_URI, DB_USER, DB_PASS);
        }
        return _instance;
    }

    /**
     * Returns a connection to the database
     */
    public Connection getConnection() {
        Connection con = null;
        try {
            con = DriverManager.getConnection("jdbc:apache:commons:dbcp:test");
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
        return con;
    }
}

我的堆栈跟踪的开始：

Apr 5, 2011 9:49:14 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Login] in context with path [/Project] 
threw exception
java.lang.RuntimeException: java.sql.SQLException: 
No suitable driver found for jdbc:mysql://localhost/dbname

是什么导致此错误？

Answer 1

尝试将驱动程序jar放在服务器lib文件夹中。（$ CATALINA_HOME / lib）

我认为即使在实例化应用程序之前也需要建立连接池。（至少这是它在Jboss中的工作方式）