Java Remove repeated try, catch, finally boilerplate from DAO

Question

I have a DAO class with many methods that have a lot of repeated code along the lines of: -

public void method1(...) {
  Connection conn = null;
  try {
             


        

Answer 1

Create an interface for ex. Executable:

 public interface Executable() {

   void exec() throws SqlException();

 }

Refactor each of your dao method to :

public void method1() {
   execute(new Executable() {

     @Override
     public void exec() throws SqlException() {
          // your code here
     }
  });
  } 

Create the following method execute in your DAO:

private void execute(Executor ex) {
    try {
      ex.exec();
    } catch(...) {
      ...
    } finally {
       ...
    }
}