20. static Initialization Block

• static fields and static methods differ from instance variables and regular methods.

• Java allows a special code block to initialize the static fields:

  
  public class className
  {
      // any field declarations
      private static DBConnection connection;
  
      static
      {
         // any initialization statements for static fields
          try {
              String url = "jdbc:mysql://localhost:3306/SampleDB";
              String user = "robert";
              String password = "secret";
              connection = DBDriverManager.getConnection(
                  url, user, password
                  );
          } catch (Exception ex)
           {
              System.err.println(
                  "Error: unable to connect to the database."
                  );
           }
      }
  
      // the rest of the class
  }