MySQL JDBC驱动程序问题

Question

我目前正在通过视频教程来学习Servlet和Jsp，我正在尝试连接到MySql数据库，但是这样做很困难，我已经按照教程中的所有步骤进行了操作，但是仍然没有连接，起初我例外正在获取java.sql.SQLException：在java.sql.DriverManager上找不到com.mysql.jdbc.Driver的合适驱动程序。

我已经在线检查了可能的解决方案，但没有一个对我有用，现在我将mysql-connector-java-5.1.49-bin.jar添加到库中，并带来了另一种异常类型。

 java.sql.SQLException: Cannot create PoolableConnectionFactory (Public Key Retrieval is not allowed)
    at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:669)
    at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:544)
    at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:753)
    at com.luv2code.web.jdbc.TextSerlets.doGet(TextSerlets.java:43)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Public Key Retrieval is not allowed
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:403)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:878)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:874)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1770)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1217)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2189)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2220)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2015)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:768)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:403)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:385)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:323)
    at org.apache.tomcat.dbcp.dbcp2.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:55)
    at org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:355)
    at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.validateConnectionFactory(BasicDataSource.java:115)
    at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:665)
    ... 27 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Public Key Retrieval is not allowed
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:403)
    at com.mysql.jdbc.Util.getInstance(Util.java:386)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
    at com.mysql.jdbc.authentication.CachingSha2PasswordPlugin.nextAuthenticationStep(CachingSha2PasswordPlugin.java:130)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1768)
    ... 44 more
我有点沮丧，因为它影响了我的学习进度，下面是我的context.xml文件，我还必须说，它现在显示出在此行错误处（在第1行中）发现的某种多重注释。

<Context>

  <Resource name="jdbc/web_student_tracker" 
            auth="Container" type="javax.sql.DataSource"
               maxActive="20" maxIdle="5" maxWait="10000"
               username="webstudent" password="webstudent" 
               driverClassName="com.mysql.jdbc.Driver"
               url="jdbc:mysql://localhost:3306/web_student_tracker?useSSL=false"/>

</Context>

我的servlet代码：

package com.luv2code.web.jdbc;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.annotation.Resource;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

/**
 * Servlet implementation class TextSerlets
 */
@WebServlet("/TextSerlets")
public class TextSerlets extends HttpServlet {
    private static final long serialVersionUID = 1L;

    @Resource(name="jdbc/web_student_tracker")
    private DataSource dataSource;

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //step 1 : Set up print writer
        PrintWriter out = response.getWriter();
        response.setContentType("text/plain");

        //step 2: Get a cinnection to the adatbase
        Connection myConn = null;
        Statement myStmt = null;
        ResultSet myRs = null;


        try {
            myConn = dataSource.getConnection();

            //Step 3 :Create a SQL statement
            String sql = "select * from student";
            myStmt = myConn.createStatement();

            //step 4: Execute SQL query
            myRs = myStmt.executeQuery(sql);

            //step 5 : Process the result set
            while (myRs.next()) {
                String email = myRs.getString("email");
                out.println(email);
            }
        }
        catch (Exception exc) {
            exc.printStackTrace();
        }
    }

}

这是我第一次在此发布信息，因此请忽略发布的任何错误。

我目前正在通过一个视频教程来学习Servlet和Jsp，我正在尝试连接到MySql数据库，但是这样做很困难，我已经按照教程中的所有步骤进行了操作，但是仍然没有...]]

Answer 1

您应该在mysql-connector allowPublicKeyRetrieval=true中添加客户端选项，以允许客户端自动从服务器请求公钥。请注意，AllowPublicKeyRetrieval = True可能允许恶意代理执行MITM攻击以获取纯文本密码，因此默认情况下为False，必须明确启用它。更改

url =“ jdbc：mysql：// localhost：3306 / web_student_tracker？useSSL = false”