ClassNotFoundException when using JDBC

Question

When I run my code, I get this error: Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.Driver; with a stack trace link to line 13 (Highlighted in the code)

I have just started using JDBC and don't know much about it, but I'll go through what I have done so far to get to where I am. As a preliminary, I am using MySQL Workbench and Apache Netbeans 11:

1) Downloaded the .jar connector file

2) Could not find the build path on netbeans 11 and did some research and couldn't find any resources linking to it, so instead used the Driver dropdown through the databases section on the services tab. Now I can see all my SQL databases and tables in my netbeans IDE.

3) Wrote the following code using the 7 steps to connect to the database, establish a connection etc

import java.sql.*;

public class GroundControlToMajorTom {

    public static void main(String[] args) throws ClassNotFoundException, SQLException {

        String url = "jdbc:mysql://localhost:3306//customers";
        String uname = "root";
        String pass = "";
        String query = "SELECT customer_id FROM customers WHERE customer_id = 1";

        Class.forName("com.mysql.jdbc.Driver");
        Connection con = DriverManager.getConnection(url, uname, pass);

        Statement st = con.createStatement();
        ResultSet rs = st.executeQuery(query);


        rs.next();
        String id = rs.getString("customer_id");

        System.out.println(id);

        st.close();
        con.close();

    }
}

4) Run the code and get a ClassNotFoundException. I did a bit of research and it seems to say that I don't have the connection to the actual driver, but I added it in the drivers section of the services for my project?

Any help would be much appreciated my dudes <3

When `Class.forName("com.mysql.jdbc.Driver");` execute , `classloader` try to load `Dricever`. When driver are loading, execute side effects (like initialization `static fields` add `blocks`), which required to execute `JDBC` library — kozmo, Jun 04 '20 at 11:14
Adding drivers to the "drivers section of the services for my project" makes the driver available to NetBeans for connecting to the database from within NetBeans itself. To be able to use it from your application, it needs to be on the classpath (build path). — Mark Rotteveel, Jun 04 '20 at 11:54

score 0 · Answer 1 · answered Jun 04 '20 at 11:12

0

You need to add the downloaded JAR to the classpath.

Try this instruction:

Open NetBeans and right-click on the project name in the Projects tab.
Select Properties.
Select Libraries.
Click the Add Jar/Folder button.
Navigate to the directory where the downloaded JAR files are.

answered Jun 04 '20 at 11:12

Łukasz Olszewski

827
5
8

Hi, For some reason in my properties there isn't a libraries section? – BurnerBoiii Jun 04 '20 at 11:14
@BurnerBoiii - What is `build and dependencies management system` you use? – kozmo Jun 04 '20 at 11:19
I am using java with maven at the moment, should I be using java with Ant? – BurnerBoiii Jun 04 '20 at 11:22
@BurnerBoiii - Does `mssql-jdbc` exist in `pom.xml`? – kozmo Jun 04 '20 at 11:26
No, I cannot see it there – BurnerBoiii Jun 04 '20 at 11:30
In the case of maven, add mysql-connector-java to section in pom.xml. Mysql dep is here https://mvnrepository.com/artifact/mysql/mysql-connector-java/8.0.20 – Łukasz Olszewski Jun 04 '20 at 11:30

kozmo · Accepted Answer · 2020-06-04T11:51:24.973

0

Add com.mysql.jdbc.Driver to CLASSPATH.

If you use maven, add to <dependencies> section of pom.xml the dependency of required driver (mysql-connector-java):

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>${mysql.version}</version>
</dependency>

for gradle

compile group: 'mysql', name: 'mysql-connector-java', version: mysqlVersion

edited Jun 04 '20 at 11:51

answered Jun 04 '20 at 11:34

kozmo

4,024
3
30
48

can I just add that anywhere in the pom.xml file? – BurnerBoiii Jun 04 '20 at 11:40
There is an error when trying to add that code, I am adding this change: ${8.0.20} and the error being called is saying that the dependency is an unrecognised tag? – BurnerBoiii Jun 04 '20 at 11:43
add to ` `section – kozmo Jun 04 '20 at 11:44
`${mysql.version}` is a variable **=>** `8.0.20` – kozmo Jun 04 '20 at 11:45

ClassNotFoundException when using JDBC

2 Answers2