Hilfsklasse um Probleme mit Checked Exceptions zu umgehen

Hilfsklasse um Probleme mit Checked Exceptions zu umgehenSeptember 2016

Eine Hilfsklasse um Probleme mit Checked Exceptions zu umgehen.
Von mir weitgehend übernommen aus dem Blog-Post  On Removing Java Checked Exceptions By Means of Perversion von James Iry.

package paConcepts;

import java.io.IOException;

/**
 * Helper class for wrapping checked exceptions in unchecked exceptions. See here:
 * 
 * http://james-iry.blogspot.de/2010/08/on-removing-java-checked-exceptions-by.html
 * 
 * Example
 * <pre>
 * 
 * public IndicationHeader getLastIndication() throws DBAccessException, UserCancelledException{
 *     Unchecked.chucks(UserCancelledException.class);
 *     
 *     return controller.runWithSession(session -> {
 *       try {
 *         return findPreviousHeaderForZeroOne(parent, controller, session); // throws UserCancelledException
 *       } catch (UserCancelledException e) {
 *         Unchecked.chuck(e);  // rethrow as unchecked exception
 *       }
 *       return null;
 *     });
 * }
 * </pre>    
 */
public class Unchecked {

  @SuppressWarnings("unchecked")
  private static <T extends Throwable, A> A pervertException(Throwable x) throws T {
    throw (T) x;
  }

  /**
   * Throws t as unchecked exception.
   * Can be used to re-throw an checked exception as unchecked.
   */
  public static <A> A chuck(Throwable t) {
    return Unchecked.<RuntimeException, A> pervertException(t);
  }

  /**
   * Used to mark that a method may throw a specific exception using chuck().
   */
  public static <T extends Throwable> void chucks(Class<T> clazz) throws T {
  }

  public static int testChuck() {
    return chuck(new IOException("unchecked, hellsyeah"));
  }

  public static void main(String[] args) {
    try {
      chucks(IOException.class);

      testChuck();
    } catch (IOException e) {
      System.out.println("Caught chucked exception " + e + ".");
    }
  }

}