Class Throwables

output/java_guava/1.4.17/Throwables.java:47–493

Static utility methods pertaining to instances of Throwable. See the Guava User Guide entry on Throwables . @author Kevin Bourrillion @author Ben Yu @since 1.0

@GwtCompatible(emulated = true)
public final class Throwables {
  private Throwables() {}

  /**
   * Throws {@code throwable} if it is an instance of {@code declaredType}. Example usage:
   *
   * <pre>
   * for (Foo foo : foos) {
   *   try {
   *     foo.bar();
   *   } catch (BarException | RuntimeException | Error t) {
   *     failure = t;
   *   }
   * }
   * if (failure != null) {
   *   throwIfInstanceOf(failure, BarException.class);
   *   throwIfUnchecked(failure);
   *   throw new AssertionError(failure);
   * }
   * </pre>
   *
   * @since 20.0
   */


  @GwtIncompatible // Class.cast, Class.isInstance
  public static <X extends Throwable> void throwIfInstanceOf(Throwable throwable, Class<X> declaredType)
    throws X {
    checkNotNull(throwable);
    if (declaredType.isInstance(throwable)) {
      throw declaredType.cast(throwable);
    }
  }

  /**
   * Propagates {@code throwable} exactly as-is, if and only if it is an instance of {@code
   * declaredType}. Example usage:
   *
   * <pre>
   * try {
   *   someMethodThatCouldThrowAnything();
   * } catch (IKnowWhatToDoWithThisException e) {
   *   handle(e);
   * } catch (Throwable t) {
   *   Throwables.propagateIfInstanceOf(t, IOException.class);
   *   Throwables.propagateIfInstanceOf(t, SQLException.class);
   *   throw Throwables.propagate(t);
   * }
   * </pre>
   *
   * @deprecated Use {@link #throwIfInstanceOf}, which has the same behavior
   *     but rejects {@code null}. This method is scheduled to be removed in July 2018.
   */

  @Deprecated
  @GwtIncompatible // throwIfInstanceOf
  public static <X extends Throwable> void propagateIfInstanceOf(@Nullable Throwable throwable, Class<X> declaredType)