java - 通过连接池建立 MySQL JDBC 连接失败 : SQL Exception: No suitable driver found

Question

不知道这段代码有什么问题？它抛出一个 SQL 异常:没有找到适合 jdbc:mysql://localhost:3306/test 的驱动程序。

但是我已经包含了 jar 文件mysql-connector-java-5.0.8-bin.jar

我尝试通过数据源通过连接池获取连接。

希望有人能帮我解决这个问题。

如果有任何日志记录错误，请忽略我希望有人解决上面突出显示的连接错误

import java.sql.*;

import javax.annotation.Resource;
import javax.naming.*;
import javax.sql.*;

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.PoolingDataSource;
import org.apache.tomcat.dbcp.pool.impl.GenericObjectPool;

public class GetConnection {
    /** Uses JNDI and Datasource (preferred style). */

    @Resource(name = "jdbc/test")
    DataSource ds;
    static final String DRIVER = "com.mysql.jdbc.Driver";
    static final String DATASOURCE_CONTEXT = "java:comp/env/jdbc/test";
    private GenericObjectPool connectionPool = null;
    public static final String URL = "jdbc:mysql://localhost:3306/test";
    public static final String USERNAME = "root";
    public static final String PASSWORD = "secret_password";

    public GetConnection() {
        System.out.println("enteredin to the new get connection");
        /*try {
            Context context = new InitialContext();
            ds = (DataSource) context.lookup(DATASOURCE_CONTEXT);
        } catch (NamingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }*/
        try {
            ds = setUp();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }


    public DataSource setUp() throws Exception {
        Class.forName(GetConnection.DRIVER).newInstance();
        connectionPool = new GenericObjectPool();
        connectionPool.setMaxActive(10);
        ConnectionFactory cf = new DriverManagerConnectionFactory(
                GetConnection.URL, GetConnection.USERNAME,
                GetConnection.PASSWORD);
        PoolableConnectionFactory pcf = new PoolableConnectionFactory(cf,
                connectionPool, null, null, false, true);
        return new PoolingDataSource(connectionPool);
    }

    public GenericObjectPool getConnectionPool() {
        return connectionPool;
    }

    /**
     * Sets up the dataSource for the connection
     */

    /**
     * returns the connection object from the datasource
     * 
     * @return the connection object
     */
    public Connection getJNDIConnection() {
        System.out.println("entered in to the get jndi connection");
                    System.out.println(ds);
                    System.out.println("checking the ds value");
        Connection result = null;
        try {
            System.out.println("Inside try");
            /*Context initialContext = new InitialContext();
            this.ds = (DataSource) initialContext.lookup(DATASOURCE_CONTEXT);*/
            if (ds != null) {
                result = this.ds.getConnection();
                System.out.println("connection done");
            } else {
                log("Failed to lookup datasource.");
                System.out.println("connection not done");
            }
        } /*catch (NamingException ex) {
            ex.printStackTrace();
            System.out.println("naming excepti9on");
            log("Cannot get connection: " + ex);
        } */catch (SQLException ex) {
            ex.printStackTrace();
            System.out.println("sqlexception");
            log("Cannot get connection: " + ex);
        }
        return result;
    }

    private static void log(Object aObject) {
        System.out.println(aObject);
    }
}

项目的上下文文件如下所示

<?xml version="1.0" encoding="UTF-8"?>
<Context>
    <Resource name="jdbc/test" auth="Container" type="javax.sql.DataSource" username="root" password="secret_password" driverClassName="com.mysql.jdbc.Driver"
    url="jdbc:mysql://localhost:3306/test;create=true" />
</Context>

堆栈跟踪如下

java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/test
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at org.apache.tomcat.dbcp.dbcp.DriverManagerConnectionFactory.createConnection(DriverManagerConnectionFactory.java:75)
    at org.apache.tomcat.dbcp.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)
    at org.apache.tomcat.dbcp.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1158)
    at org.apache.tomcat.dbcp.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:106)
    at com.new.connection.GetConnection.getJNDIConnection(GetConnection.java:81)
    at com.new.daoclass.CreateUserAgreement.createUser(CreateUserAgreement.java:17)
    at com.new.bean.useragreement.UserAgreementBean.createagreement(UserAgreementBean.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.el.parser.AstValue.invoke(AstValue.java:262)
    at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278)
    at org.apache.myfaces.view.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:83)
    at javax.faces.component._MethodExpressionToMethodBinding.invoke(_MethodExpressionToMethodBinding.java:88)
    at org.apache.myfaces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:100)
    at javax.faces.component.UICommand.broadcast(UICommand.java:120)
    at javax.faces.component.UIViewRoot._broadcastAll(UIViewRoot.java:937)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:271)
    at javax.faces.component.UIViewRoot._process(UIViewRoot.java:1249)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:675)
    at org.apache.myfaces.lifecycle.InvokeApplicationExecutor.execute(InvokeApplicationExecutor.java:34)
    at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:171)
    at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:189)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Answer 1

请将其放入${CATALINA_HOME}/lib目录下并重启服务器。这是因为您正在尝试从池访问连接，该连接应由 tomcat 在配置数据源期间创建。因此，它需要mysql-driver.jar来配置数据源。因此，通过将 jar 放在 tomcat/lib 中来提供它。可以从这个link下载。