What is wrong with the code there are lots of error while debugging. I am writing a code for a singleton class to connect with the database mysql.
Here is my code
package com.glomindz.mercuri.util;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
public class MySingleTon {
String url = "jdbc:mysql://localhost:3306/";
String dbName = "test";
String driver = "com.mysql.jdbc.Driver";
String userName = "root";
String password = "";
private static MySingleTon myObj;
private Connection Con ;
private MySingleTon() {
System.out.println("Hello");
Con= createConnection();
}
@SuppressWarnings("rawtypes")
public Connection createConnection() {
Connection connection = null;
try {
// Load the JDBC driver
Class driver_class = Class.forName(driver);
Driver driver = (Driver) driver_class.newInstance();
DriverManager.registerDriver(driver);
connection = DriverManager.getConnection(url + dbName);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
}
return connection;
}
/**
* Create a static method to get instance.
*/
public static MySingleTon getInstance() {
if (myObj == null) {
myObj = new MySingleTon();
}
return myObj;
}
public static void main(String a[]) {
MySingleTon st = MySingleTon.getInstance();
}
}
I am new to java. Please help.
It seems the mysql connectivity library is not included in the project. Solve the problem following one of the proposed solutions:
Add the mysql-connector dependency to the pom.xml project file:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.39</version>
</dependency>
Here you are all the versions: https://mvnrepository.com/artifact/mysql/mysql-connector-java
Add the jar library manually to the project.
Right Click the project -- > build path -- > configure build path
In Libraries Tab
press Add External Jar
and Select
your jar.
You can find zip for mysql-connector here
When building the project, java throws you an exception because a file (the com.mysql.jdbc.Driver class) from the mysql connectivity library is not found. The solution is adding the library to the project, and java will find the com.mysql.jdbc.Driver