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POHow to use Java Property File?
 

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    <p>I need to use <code>.properties</code> file in Java to store database information. </p> <p>Here is my database connector class. It giving <code>NullPointerException</code>. What is the issue with my code ?</p> <p>Note that I haven't' assign those property file values. DB connection values are still hard coded.</p> <pre><code>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; } } </code></pre>
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    1. CONullPointerException is probably because of un-initialized property object. You should initialize by calling private Properties property = new Properties();
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      1. USgmansoor
 

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