Utility class

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In computer programming, a utility class is a class that defines a set of methods that perform common, often re-used functions. Most utility classes define these common methods under static (see Static variable) scope. Examples of utility classes include java.util.Collections [1] which provides several utility methods (such as sorting) on objects that implement a Collection (java.util.collection [2] ).

Example[edit]

DbConnection.java(util class):-
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
 
public final class DbConnection {
	public static Connection con;
	public static String uId = "User_id";
	public static String pwd = "password";
 
	private DbConnection {
		// Utility classes should always be final and have an private constructor
	}
 
	public static Connection createConnection() {
		try {
			// Loading the driver
			Class.forName("oracle.jdbc.driver.OracleDriver");
			// Creating a connection
			String conUrl = "jdbc:oracle:thin:@Host_id:Port:SID";
			con = DriverManager.getConnection(conUrl, uId, pwd);
		} catch(ClassNotFoundException e) {
			System.out.println("Driver not found");	
		} catch (SQLException sq1ex) {
			System.out.println("Connection exception" + sq1ex);
		}
 
		return con;
	}
 
	public static void closeConnection(Connection con) {
		if(con != null) {
			try {
				con.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
 
	public static void closeStatement(PreparedStatement ps) {
		if(ps != null) {
			try {
				ps.close();
			} catch (SQLException e) {
				// TODO Auto-generated a catch block
				e.printStackTrace();
			}
		}
	}
}

See also[edit]

External links[edit]

  • Utility Pattern: For a utility class, which does not require instantiation and only has static methods, use a private constructor