Question

我正在尝试从Java连接到MySQL，我收到以下错误。

java.sql.SQLException：拒绝用户＆root;＆＃39; @＆＃39; localhost＆＃39; （使用密码：是）在com.mysql.jdbc.SQLError.createSQLException（SQLError.java:1073）在com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:4096）在com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:4028）在com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:951）在com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication（MysqlIO.java:1717）在com.mysql.jdbc.MysqlIO.doHandshake（MysqlIO.java:1276）在com.mysql.jdbc.ConnectionImpl.coreConnect（ConnectionImpl.java:2395）在com.mysql.jdbc.ConnectionImpl.connectOneTryOnly（ConnectionImpl.java:2428）在com.mysql.jdbc.ConnectionImpl.createNewIO（ConnectionImpl.java:2213）在com.mysql.jdbc.ConnectionImpl。（ConnectionImpl.java:797）在com.mysql.jdbc.JDBC4Connection。（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）在com.mysql.jdbc.Util.handleNewInstance（Util.java:411）在com.mysql.jdbc.ConnectionImpl.getInstance（ConnectionImpl.java:389）在com.mysql.jdbc.NonRegisteringDriver.connect（NonRegisteringDriver.java:305） at java.sql.DriverManager.getConnection（Unknown Source） at java.sql.DriverManager.getConnection（Unknown Source）在com.javawebtutor.jsf.LoginBean.dbData（LoginBean.java:63）在com.javawebtutor.jsf.LoginBean.checkValidUser（LoginBean.java:80） 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）在org.apache.el.parser.AstValue.invoke（AstValue.java:278） at org.apache.el.MethodExpressionImpl.invoke（MethodExpressionImpl.java:273） at org.apache.jasper.el.JspMethodExpression.invoke（JspMethodExpression.java:70） at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke（MethodBindingMethodExpressionAdapter.java:88） at com.sun.faces.application.ActionListenerImpl.processAction（ActionListenerImpl.java:102）在javax.faces.component.UICommand.broadcast（UICommand.java:315）在javax.faces.component.UIViewRoot.broadcastEvents（UIViewRoot.java:794）在javax.faces.component.UIViewRoot.processApplication（UIViewRoot.java:1259） at com.sun.faces.lifecycle.InvokeApplicationPhase.execute（InvokeApplicationPhase.java:81）在com.sun.faces.lifecycle.Phase.doPhase（Phase.java:101）在com.sun.faces.lifecycle.LifecycleImpl.execute（LifecycleImpl.java:118）在javax.faces.webapp.FacesServlet.service（FacesServlet.java:593）在org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:303）在org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:208）在org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52）在org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:241）在org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:208）在org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:220）在org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:122）在org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:505）在org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:170）在org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:103）在org.apache.catalina.valves.AccessLogValve.invoke（AccessLogValve.java:956）在org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:116）在org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:423）在org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1079） at org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process（AbstractProtocol.java:625）在org.apache.tomcat.util.net.AprEndpoint $ SocketProcessor.doRun（AprEndpoint.java:2522）在org.apache.tomcat.util.net.AprEndpoint $ SocketProcessor.run（AprEndpoint.java:2511） 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）在java.lang.Thread.run（未知来源）异常在进程中发生：java.sql.SQLException：拒绝用户＆root;＆＃39; @＆＃39; localhost＆＃39; （使用密码：是）＆＃34;

感谢您的帮助，我对此非常陌生。我很肯定密码和用户名都是正确的，所以我不确定从哪里开始。这是我连接数据库的代码：

package com.javawebtutor.jsf;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;


@ManagedBean(name="loginBean")
@SessionScoped
public class LoginBean {
private String userName;
private String password;
private String dbuserName;

private String dbpassword;
Connection connection;
Statement statement;
ResultSet resultSet;
String SQL;


public String getUserName() {
    return userName;
}

public void setUserName(String userName) {
    this.userName = userName;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public String getDbuserName() {
    return dbuserName;
}

public void setDbuserName(String dbuserName) {
    this.dbuserName = dbuserName;
}

public String getDbpassword() {
    return dbpassword;
}

public void setDbpassword(String dbpassword) {
    this.dbpassword = dbpassword;
}

public void dbData(String userName)
{
    Connection con = null;
    String conUrl = "jdbc:mysql://localhost:3306/test; user=root; password=pass;";
    try
    {
        Class.forName("com.mysql.jdbc.Driver");
        con = DriverManager.getConnection(conUrl);
        //connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test",user = "root","pass");
        statement = connection.createStatement();
        SQL = "Select * from USER_DETAIL where username like ('" + userName +"')";
        resultSet = statement.executeQuery(SQL);
        resultSet.next();
        dbuserName = resultSet.getString(1).toString();
        dbpassword = resultSet.getString(2).toString();
    }
    catch(Exception ex)
    {
        ex.printStackTrace();
        System.out.println("Exception Occured in the process :" + ex);
    }
}

public String checkValidUser()
{
    dbData(userName);

    if(userName.equalsIgnoreCase(dbuserName))
    {

        if(password.equals(dbpassword))
            return "success";
        else
        {
            return "failure";
        }
    }
    else
    {
        return "failure";
    }
}
}

Answer 1

在MySQL服务器管理中，用户为specified with both allowable hostnames and passwords。如果root用户未设置为包含localhsot作为客户端，则会拒绝本地计算机上的登录。有关详细信息，请参阅this question and its accepted answer。

Answer 2

你能尝试这样吗

con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","pass");

由于getConnection函数需要3个参数：url + dbname，username，password。

Answer 3

您的密码似乎有误。

您可以尝试下面给出的空密码。

String conUrl = "jdbc:mysql://localhost:3306/test; user=root; password=;";

为什么从Java连接到MySQL数据库会被拒绝访问？

3 个答案: