javamysqljdbcpropertiesnullpointerexception

How to use .properties file to store database connection properties?


I need to use .properties file in Java to store a database information.

Here is my database connector class. It's giving me a NullPointerException. What is the issue with my code?

Note, that I haven't assigned those property file values. DB connection values are still hard coded.

import java.io.IOException;
import java.io.InputStream;
import java.sql.Statement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;


public final class Database {

    public Connection connection;
    private Statement statement;
    private Properties property;
    public static Database database;

    private Database() {

        String url = "jdbc:mysql://localhost:3306/";
        String dbName = "edus";
        String driver = "com.mysql.jdbc.Driver";
        String userName = "root";
        String password = "";
        try {
            InputStream is = Database.class.getClassLoader().getResourceAsStream(
                "config.properties");
            property.load(is);
            System.out.println(property.getProperty("db_user"));
            System.out.println(property.getProperty("db_password"));
            System.out.println(property.getProperty("db_name"));

            Class.forName(driver).newInstance();
            this.connection = (Connection) DriverManager.getConnection(url + dbName,
                    userName, password);
        }catch (IOException ex) {
            Logger.getLogger(Database.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ClassNotFoundException e) {
            System.out.println("JDBC driver is missing");
        } catch (InstantiationException | IllegalAccessException | SQLException e) {
            e.printStackTrace();
        } 
    }

    public static synchronized Database getDatabaseConnection() {
        if (database == null) {
            database = new Database();
        }
        return database;

    }        
}

Solution

  • config.properties is not lying under classpath. It should be under classes folder.

    you can also try

    Database.class.getClassLoader().getResourceAsStream(
                    "com/lk/apiit/eduservice/config.properties");
    

    As Roman C pointed out you also need to initialize Properties Object first

    Properties property = new Properties();