Connecting to MySQL using JDBC

Question

I have searched the internet trying to find solutions on using java and JDBC to connect to MySQL. Unfortunately I have found multiple answers and none that solved my problem.

I downloaded the JDBC from MySQL, and unzipped the file to find the .jar. I placed the .jar in my C:/Program Files (X86)/Java/JDK.../JRE/lib/ext folder. I set my environmental variable classpath (maybe CLASSPATH, ClassPath ??) to the following:

%CLASSPATH%;.;C:\Program Files (x86)\Java\jdk1.8.0_65\jre\lib\ext

I use the script I composed based on all the different solutions I have seen to get this:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;


public class MySql {

    public static void main(String[] args)
    {
        Connection con = getConnection();
        if (con != null) {
            System.out.println("Connection Made");
        }
        else {
            System.out.println("Connection not made");
        }
    }

    private static Connection getConnection() {


        Connection con = null;  
        try {
            Class.forName("com.mysql.jdbc");
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/sakila", "java", "java");
            System.out.println("Connection Made");

            conn.close();

        } 
        catch (SQLException e)
        {
            System.out.println(e.getMessage());
            System.exit(0);
        }
        catch (ClassNotFoundException e)
        {
            System.out.println(e.getMessage());
            System.exit(0);
        }
        return con;
    }


 }

It compiles with javac MySql.java. Then when it runs (java MySql) I get com.mysql.jdbc. I have read that I don't need to register the driver, but when I remove Class.forName all I get is 'cannot find JDBC driver' error.

I can't narrow down my problem to either: 1). Classpath not setup correctly. 2). Improper java connection code. 3). Unable to locate MySQL server.

Any help would be appreciated.

Edit -

I placed the .jar file onto Desktop for testing purposes. Changed system classpath variable:

%CLASSPATH%;.;C:\User\User\Desktop\mysql-connector-java-5.1.38-bin.jar

Then when I add the trace for the error statement I get:

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at java.net.URLClassLoader.findClass<Unkown Source>
    at java.lang.ClassLoader.loadclass (Unknown source)
    at sun.misc.Launcher$AppClassLoader.loadclass(Unkown Source)
    etc.
    etc.

edit 2 - I have spent two days using Connect Java to a MySQL database as a resource and none of the instructions I have followed have solved my problem.

Answer 1

Instead of

System.out.println(e.getMessage());

Do this

e.printStackTrace();

You will see that the exception is:

java.lang.ClassNotFoundException: com.mysql.jdbc
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at MySql.getConnection(MySql.java:24)
    at MySql.main(MySql.java:10)

Remove the Class.forName. You might get an access denied or some other error but it will solve the ClassNotFoundException. Here is the final edited version that should work:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class MySql {

    public static void main(String[] args)
    {
        Connection con = getConnection();
        if (con != null) {
            System.out.println("Connection Made");
        }
        else {
            System.out.println("Connection not made");
        }
    }

    private static Connection getConnection() {
        Connection con = null;  
        try {
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/sakila", "java", "java");
            System.out.println("Connection Made");
            conn.close();
        } 
        catch (SQLException e)
        {
            e.printStackTrace();
            System.exit(0);
        }
        return con;
    }
 }

Answer 2

If you need Class.forName() you have to use correct class:

     Class.forName("com.mysql.jdbc.Driver");

But with JDBC 4 that has become no longer needed.

Create full Exception stack traces and use the result to search here - most common errors have been solved here before.

NoSuitableDriverFound is a very strong indication your mysql-connector.jar (not the .zip....) is missing from your classpath when you run your code.

You could try like this:

Run java -cp .;C:\User\User\Desktop\mysql-connector-java-5.1.38-bin.jar MySql

Answer 3

I think you must add the path including the jar file name of the driver in your classpath. Like so:

%CLASSPATH%;.;C:\Program Files (x86)\Java\jdk1.8.0_65\jre\lib\ext\mysql-connector-java-xxx.jar

Answer 4

If your Java is version 6 or above you doesn't need Class.formName(...) code. And for ensure that everything works, compile and execute your code in the follow way. To compile:

java -cp PATH_TO_DRIVER; YOUR_CLASS.java

To execute:

java -cp PATH_TO_DRIVER; YOUR_CLASS

Change YOUR_CLASS to the name of your class and PATH_TO_DRIVER to the path where you download the MySQL driver.

Hope it helps!

Answer 5

Try this code!

  public static void main(String[] argv) {

    try {
        Class.forName("com.mysql.jdbc.Driver");
    } catch (ClassNotFoundException e) {
        System.out.println("Where is your MySQL JDBC Driver?");
        e.printStackTrace();
        return;
    }

    System.out.println("MySQL JDBC Driver Registered!");
    Connection connection = null;

    try {
        connection = DriverManager
        .getConnection("jdbc:mysql://localhost:3306/yourSCHEMAname,"login", "password");

    } catch (SQLException e) {
        System.out.println("Connection Failed! Check output console");
        e.printStackTrace();
        return;
    }

    if (connection != null) {
        System.out.println("You made it, take control your database now!");
    } else {
        System.out.println("Failed to make connection!");
    }
  }
}