Checked exceptions in Java have to be handled or rethrown. This results in a lot of unnecessary code. The following example shows the try catch block how to handle the checked exceptions thrown by new FileReader("pathToFile") - throws FileNotFoundException and reader.read() - throws IOException:

    public void openSomeFileInJava(){
      try {
            FileReader reader = new FileReader("pathToFile");
            int i=0;
            while(i != -1){
              i = reader.read();
              //Do something with what was read
            }
      reader.close();
      } catch (FileNotFoundException e) {
           //Exception handling code
        } catch (IOException e) {
        //Exception handling code
      }
    }

Kotlin does not have any checked exceptions. It's up to the client code if they want to handle the exception. Exception handling is not forced on the client.