Question

I'm having troubles with my project , it involves JDBC and Mysql connection .

When I do the following :

private Statement m_statement = null;               // statement 
private Connection m_connection = null;             //  connection

/**
 * Constructor #1 of the Database class
 * @throws ClassNotFoundException
 */
public Database() throws ClassNotFoundException
{
    try
    {
        Class.forName("com.mysql.jdbc.Driver");
        MysqlDataSource ds = new MysqlConnectionPoolDataSource();
        ds.setServerName("localhost");
        ds.setPort(3306);
        ds.setUser("root");
        ds.setPassword("");
        this.m_connection = ds.getConnection();
        this.m_statement = this.m_connection.createStatement();
    }

    catch (SQLException s)
    {
        System.out.println("SQL statement is not executed! 2!");
    }

}

When I try to connect with the above code , the connection doesn't work ,here is the stacktrace :

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: NO)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4074)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4006)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:919)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1694)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1244)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2397)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2430)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813)
    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:411)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334)
    at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:443)
    at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:141)
    at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:111)
    at db.Database.<init>(Database.java:99)
    at controller.LoginPage.doGet(LoginPage.java:61)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

How can I fix it ?

Regards

Was it helpful?

Solution

I encounter the same error, this is how I fixed it:

I used DriverManager class like this:

    Class.forName("com.mysql.jdbc.Driver");
    Connection Hello = DriverManager.getConnection("jdbc:mysql://YOUR-URL-HERE", "USERNAME", "PASSWORD");

And that's it. Also, when selecting a table, remenber to put the DB name first, like:

    "DB_NAME.TABLE_NAME".

OTHER TIPS

TO check if mysql has a password, go to the directory where you installed mysql, and in the bin directory try to bring up mysql prompt using

./mysql –u root mysql

If the login goes through without any problem, it means no password is set.
You can use mysqadmin script to set/reset password.

./mysqladmin –u root password "password string"

Looks like you've only just installed mysql. Run mysql_secure_installation. It will prompt you for a root password, among other things.

I had the same problem. You need to set a password for the user. Go to the mysql console .

$ mysqladmin -u root password myFirstpassword

Then change your password in the java program

Either the username/password is wrong or the user is missing privileges to access the schema/table. Grant privileges using

GRANT ALL PRIVILEGES ON . TO 'root'@'localhost' WITH GRANT OPTION

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