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MySQL drivers not loading?

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Join Date: Jul 2005

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MySQL drivers not loading?

Nov 7th, 2005

Using the following:

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 Java Syntax (Toggle Plain Text) 
    protected void testDriver ( )  {
    String drivers = "nada";
    try {
      Class.forName("com.mysql.jdbc.Driver").newInstance();
    } catch ( java.lang.ClassNotFoundException e ) {
      System.out.println("MySQL JDBC Driver not found ... ");
    } catch (IllegalAccessException ex) {
      System.out.println("Illegal Access");
    } catch (InstantiationException ex) {
      System.out.println("Instantiation problem");
    }
    System.out.println("Midway drivers are " + drivers);
    try {
      drivers = (String) java.security.AccessController.doPrivileged(
          new sun.security.action.GetPropertyAction("jdbc.drivers"));
    } catch (Exception ex) {
          drivers = "balderdash";
    }
    System.out.println(drivers);
  }
    protected void testDriver ( )  {
    String drivers = "nada";
    try {
      Class.forName("com.mysql.jdbc.Driver").newInstance();
    } catch ( java.lang.ClassNotFoundException e ) {
      System.out.println("MySQL JDBC Driver not found ... ");
    } catch (IllegalAccessException ex) {
      System.out.println("Illegal Access");
    } catch (InstantiationException ex) {
      System.out.println("Instantiation problem");
    }
    System.out.println("Midway drivers are " + drivers);
    try {
      drivers = (String) java.security.AccessController.doPrivileged(
          new sun.security.action.GetPropertyAction("jdbc.drivers"));
    } catch (Exception ex) {
          drivers = "balderdash";
    }
    System.out.println(drivers);
  }

I get the output
"Midway drivers are nada"
"null"

This tells me that java.security.AccessController.doPrivileged isn't quite doing what I expected. Why isn't it picking up a driver? Is it the proper usage? How /do/ you load a mySQL driver, anyways?
Other than the printlns, this is about the same as the mySQL code I had seen other places.
Thanks,

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Postaholic

Re: MySQL drivers not loading?

Nov 7th, 2005

Where are you making a connection to the DB?

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Re: MySQL drivers not loading?

Nov 7th, 2005

•

Originally Posted by server_crash

Where are you making a connection to the DB?

Hello Wizard!
This fellow wrote a two-step connection process; the first to just fire the Class.forName with the assumption that the driver was good, and then the next to see whether the user-input database host name was any good.
That didn't quite make sense to me either, so I just rewrote it:

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 Java Syntax (Toggle Plain Text) 
public int DBtest( String hst ) {
 
    host = hst;
    String url = "";
 
//    testDriver ( );
    String drivers = "nada";
    try {
      Class.forName("com.mysql.jdbc.Driver");//.newInstance()
    } catch ( java.lang.ClassNotFoundException e ) {
      System.out.println("MySQL JDBC Driver not found ... ");
    }
/*    System.out.println("Midway drivers are :" + drivers);
    try {
      drivers = (String) java.security.AccessController.doPrivileged(
          new sun.security.action.GetPropertyAction("jdbc.Driver"));
    } catch (Exception ex) {
          drivers = "balderdash";
    }
    if (drivers == null) System.out.println("It really is NULL");
    System.out.println("Ending drivers are :" + drivers);
*/
    try {
      //url = "jdbc:mysql://" + host + "/" + database + "?user=" + username + "&password=" + password;
      url = "jdbc:mysql://" + host + "/" + database;
      Connection con = DriverManager.getConnection(url, "username", "password");
      con.close();
      return 1;
    } catch ( java.sql.SQLException e ) {
      System.out.println(e);
      return 0;
    }
  }
public int DBtest( String hst ) {

    host = hst;
    String url = "";

//    testDriver ( );
    String drivers = "nada";
    try {
      Class.forName("com.mysql.jdbc.Driver");//.newInstance()
    } catch ( java.lang.ClassNotFoundException e ) {
      System.out.println("MySQL JDBC Driver not found ... ");
    }
/*    System.out.println("Midway drivers are :" + drivers);
    try {
      drivers = (String) java.security.AccessController.doPrivileged(
          new sun.security.action.GetPropertyAction("jdbc.Driver"));
    } catch (Exception ex) {
          drivers = "balderdash";
    }
    if (drivers == null) System.out.println("It really is NULL");
    System.out.println("Ending drivers are :" + drivers);
*/
    try {
      //url = "jdbc:mysql://" + host + "/" + database + "?user=" + username + "&password=" + password;
      url = "jdbc:mysql://" + host + "/" + database;
      Connection con = DriverManager.getConnection(url, "username", "password");
      con.close();
      return 1;
    } catch ( java.sql.SQLException e ) {
      System.out.println(e);
      return 0;
    }
  }

For whatever reason, GetPropertyAction really was returning NULL, even though Class.forName() isn't throwing the "Not Found" error. Anyway, the only output now is, "java.sql.SQLException: No suitable driver". It's possible that MySQL has changed drastically since the previous guy was programming on this, but I was hoping the same drivers were still valid.

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Re: MySQL drivers not loading?

Nov 8th, 2005

JDBC drivers are usually dependent on specific versions of the database engine in use.
Find out what version of mySQL you're using and what driver you need for it.

As people are clearly allowed to attack me but I'm not allowed to defend myself, I no longer post to this site.

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Re: MySQL drivers not loading?

Nov 8th, 2005

•

Originally Posted by jwenting

JDBC drivers are usually dependent on specific versions of the database engine in use.
Find out what version of mySQL you're using and what driver you need for it.

All right... I just downloaded MySQL 5, and the project's running on MySQL 4.0.14, and they both claim to be able to use driver 3.51. Unfortunately, after installing the 3.51 driver, the program is still saying, "No suitable driver."

Also tried adding

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static {
    System.loadLibrary("msvcr71");
    System.loadLibrary("myodbc3");
    System.loadLibrary("myodbc3S");
  }
static {
    System.loadLibrary("msvcr71");
    System.loadLibrary("myodbc3");
    System.loadLibrary("myodbc3S");
  }

, which corresponds with the three dlls that came with the 3.51 version, but still no dice. Strangely, I couldn't find a "driver.class" or "driver.java" file in the downloads.

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Re: MySQL drivers not loading?

Nov 18th, 2005

Okay, a rundown:
Running in JBuilder 2005
Using the following:

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 Java Syntax (Toggle Plain Text) 
    try {
      java.sql.Driver mySQLDriver = (Driver) Class.forName("com.mysql.jdbc.Driver").newInstance();
      DriverManager.registerDriver(mySQLDriver);
    }catch(Exception e){
      e.printStackTrace();
    }
    java.util.Enumeration driverlist = DriverManager.getDrivers();
    if(!driverlist.hasMoreElements()){
      System.out.println("If you see this than something is really screwed on this system...");
    }
 
    try {
      Object Instants = Class.forName("com.mysql.jdbc.Driver").newInstance();
    } catch ( java.lang.ClassNotFoundException e ) {
      System.out.println("MySQL JDBC Driver not found ... ");
    } catch (IllegalAccessException ex) {
      System.out.println("Illegal Access");
    } catch (InstantiationException ex) {
      System.out.println("Instantiation problem");
    }
    java.util.Enumeration driverlist2 = DriverManager.getDrivers();
    Object ob = null;
    if(driverlist2.hasMoreElements()) System.out.println("list2 isn't empty");
    else System.out.println("list2 is empty");
    for (; driverlist2.hasMoreElements(); ){
      ob = driverlist2.nextElement();
      System.out.println(ob);
      System.out.println("Filler");
    }
    try{
      Connection c = DriverManager.getConnection("jdbc:mysql://ycb","root","R00T");
      c.close();
    } catch ( java.sql.SQLException e) {
      System.out.println("The exception is " + e);
    }
    try {
      java.sql.Driver mySQLDriver = (Driver) Class.forName("com.mysql.jdbc.Driver").newInstance();
      DriverManager.registerDriver(mySQLDriver);
    }catch(Exception e){
      e.printStackTrace();
    }
    java.util.Enumeration driverlist = DriverManager.getDrivers();
    if(!driverlist.hasMoreElements()){
      System.out.println("If you see this than something is really screwed on this system...");
    }

    try {
      Object Instants = Class.forName("com.mysql.jdbc.Driver").newInstance();
    } catch ( java.lang.ClassNotFoundException e ) {
      System.out.println("MySQL JDBC Driver not found ... ");
    } catch (IllegalAccessException ex) {
      System.out.println("Illegal Access");
    } catch (InstantiationException ex) {
      System.out.println("Instantiation problem");
    }
    java.util.Enumeration driverlist2 = DriverManager.getDrivers();
    Object ob = null;
    if(driverlist2.hasMoreElements()) System.out.println("list2 isn't empty");
    else System.out.println("list2 is empty");
    for (; driverlist2.hasMoreElements(); ){
      ob = driverlist2.nextElement();
      System.out.println(ob);
      System.out.println("Filler");
    }
    try{
      Connection c = DriverManager.getConnection("jdbc:mysql://ycb","root","R00T");
      c.close();
    } catch ( java.sql.SQLException e) {
      System.out.println("The exception is " + e);
    }

I get the following output:
list2 isn't empty So it found and loaded a driver...
com.mysql.jdbc.Driver@650646 Here it is...
Filler Here's a line I did to make sure I wasn't printing a blank list...
The exception is java.sql.SQLException: No suitable driver And I'm still getting this result.
If it's in the DriverManager, why wouldn't it connect? Is it just a bad driver (I wouldn't think so, it came with the same version as a working program) or is the driver not in the right place, or is there a process I'm missing somewhere?

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Phaelax

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Re: MySQL drivers not loading?

Nov 26th, 2005

You'll get that error if it doesn't connect to the DB, has nothing to do with not finding the Driver.
This is all I have to connect to my DB:

Class.forName("com.mysql.jdbc.Driver").newInstance();
String url = "jdbc:mysql://"+host;
connection = DriverManager.getConnection(url, user, password);

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Re: MySQL drivers not loading?

Dec 3rd, 2005

Okay, trying yours but adding error catching and helpful printlns:

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public int DBtest2(String hst){
  int worked = 1;
  try{Class.forName("com.mysql.jdbc.Driver").newInstance();}
  catch(Exception e){System.out.println("Class Error; exception " + e); worked = 0;}
  String url = "jdbc:mysql://"+hst;
  try{Connection conn = DriverManager.getConnection(url, username, password); conn.close();}
  catch(Exception e){System.out.println("Connection error; exception " + e); worked = 0;}
  return worked;
}
public int DBtest2(String hst){
  int worked = 1;
  try{Class.forName("com.mysql.jdbc.Driver").newInstance();}
  catch(Exception e){System.out.println("Class Error; exception " + e); worked = 0;}
  String url = "jdbc:mysql://"+hst;
  try{Connection conn = DriverManager.getConnection(url, username, password); conn.close();}
  catch(Exception e){System.out.println("Connection error; exception " + e); worked = 0;}
  return worked;
}

I get: Connection error; exception java.sql.SQLException: No suitable driver
Hmm... seeing if I can find what this error message means, since it's obvious I have a driver in there, and it's supposedly the one that belongs with the version MySQL I'm using.
Looks like most other people are having problems with how their url is formatted. Checking that out...

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Re: MySQL drivers not loading?

Dec 3rd, 2005

More fidgeting; after changing the connection's catch statement to:

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catch (SQLException ex) {
            // handle any errors
            System.out.println("SQLException: " + ex.getMessage());
            System.out.println("SQLState: " + ex.getSQLState());
            System.out.println("VendorError: " + ex.getErrorCode());
            worked = 0;
        }
catch (SQLException ex) {
            // handle any errors
            System.out.println("SQLException: " + ex.getMessage());
            System.out.println("SQLState: " + ex.getSQLState());
            System.out.println("VendorError: " + ex.getErrorCode());
            worked = 0;
        }

I got:
SQLException: No suitable driver
SQLState: 08001
VendorError: 0

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Re: MySQL drivers not loading?

#10

Dec 4th, 2005

what does your full host address look like? If you dont specify a database, it must end with a "/".

jdbc:mysql://localhost/
or
jdbc:mysql://localhost/myDB

If that syntax isn't exact, you can get that "no driver" error.