Applying the action from ifPresentOrElse() on Every element of the stream-CodePudding

In my Java application I'm using the following stream:

columns.stream()
    .map(columnEncryptors::get)
    .findFirst()
    .ifPresentOrElse(columnEncryptor -> 
        columnEncryptor.encrypt(bankTransaction),
        () -> { throw new IllegalArgumentException("No encryptor"); }
    );

The columns list met contains 9 strings, the code above is performing the action only for the first one, but not the other 8.

How can change the code fire the same action for every element in the columns list?

CodePudding user response：

To apply the action on every element you don't need findFirst, deal with Optional and there's no need to create a stream at all.

columns.forEach(column -> {
    ColumnEncryptor encryptor = columnEncryptors.get(column);
    if (encryptor != null) columnEncryptor.encrypt(bankTransaction)
    else throw new IllegalArgumentException("No encryptor");
});

CodePudding user response：

The reason you are only able to process first one is because of the .findFirst. You can try using .forEach instead then all the elements in the stream will be processed:

columns.stream()
  .map(columnEncryptors::get)
  .forEach((columnEncryptor) -> {
    <LOGIC FOR EACH ELEMENT> 
  })