Unthrow.java

/*
 * Copyright (c) 2016 ingenieux Labs
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package br.com.ingenieux.mojo.apigateway.util;

import java.util.stream.Stream;

/**
 * Throw unchecker
 *
 * @author SeregaLBN how to use - see unit test
 */
public class Unthrow {
  @SuppressWarnings("unchecked")
  static <R, E extends Exception> R rethrow(Exception ex) throws E {
    throw (E) ex;
  }

  public static <R, E extends Exception> Stream<R> of(Stream<R> stream) throws E {
    return stream;
  }

  public static <R, E1 extends Exception, E2 extends Exception> Stream<R> of2(Stream<R> stream) throws E1, E2 {
    return stream;
  }

  public static <R, E1 extends Exception, E2 extends Exception, E3 extends Exception> Stream<R> of3(Stream<R> stream) throws E1, E2, E3 {
    return stream;
  }

  public static <R, E1 extends Exception, E2 extends Exception, E3 extends Exception, E4 extends Exception> Stream<R> of4(Stream<R> stream)
      throws E1, E2, E3, E4 {
    return stream;
  }

  ////////////////////////////////// interfaces ProcedureN //////////////////////////////////

  /**
   * like as {@link java.lang.Runnable}
   */
  @FunctionalInterface
  public interface IProc0 {
    void accept() throws Exception;
  }

  /**
   * like as {@link java.util.function.Consumer}
   */
  @FunctionalInterface
  public interface IProc1<T> {
    void accept(T t) throws Exception;
  }

  /**
   * like as {@link java.util.function.BiConsumer}
   */
  @FunctionalInterface
  public interface IProc2<T1, T2> {
    void accept(T1 t1, T2 t2) throws Exception;
  }

  @FunctionalInterface
  public interface IProc3<T1, T2, T3> {
    void accept(T1 t1, T2 t2, T3 t3) throws Exception;
  }

  ////////////////////////////////// interfaces FunctionN //////////////////////////////////

  /**
   * like as {@link java.util.concurrent.Callable}
   */
  @FunctionalInterface
  public interface IFunc0<R> {
    R apply() throws Exception;
  }

  /**
   * like as {@link java.util.function.Function}
   */
  @FunctionalInterface
  public interface IFunc1<R, T> {
    R apply(T t) throws Exception;
  }

  /**
   * like as {@link java.util.function.BiFunction}
   */
  @FunctionalInterface
  public interface IFunc2<R, T1, T2> {
    R apply(T1 t1, T2 t2) throws Exception;
  }

  @FunctionalInterface
  public interface IFunc3<R, T1, T2, T3> {
    R apply(T1 t1, T2 t2, T3 t3) throws Exception;
  }

  ////////////////////////////////// wrap Procedures //////////////////////////////////

  public static void wrapProc(IProc0 proc) {
    try {
      proc.accept();
    } catch (Exception ex) {
      rethrow(ex);
    }
  }

  public static <T> void wrapProc(IProc1<T> proc, T t) {
    try {
      proc.accept(t);
    } catch (Exception ex) {
      rethrow(ex);
    }
  }

  public static <T1, T2> void wrapProc(IProc2<T1, T2> proc, T1 t1, T2 t2) {
    try {
      proc.accept(t1, t2);
    } catch (Exception ex) {
      rethrow(ex);
    }
  }

  public static <T1, T2, T3> void wrapProc(IProc3<T1, T2, T3> proc, T1 t1, T2 t2, T3 t3) {
    try {
      proc.accept(t1, t2, t3);
    } catch (Exception ex) {
      rethrow(ex);
    }
  }

  ////////////////////////////////// wrap Functions //////////////////////////////////

  public static <R> R wrap(IFunc0<R> func) {
    try {
      return func.apply();
    } catch (Exception ex) {
      return rethrow(ex);
    }
  }

  public static <R, T> R wrap(IFunc1<R, T> func, T t) {
    try {
      return func.apply(t);
    } catch (Exception ex) {
      return rethrow(ex);
    }
  }

  public static <R, T1, T2> R wrap(IFunc2<R, T1, T2> func, T1 t1, T2 t2) {
    try {
      return func.apply(t1, t2);
    } catch (Exception ex) {
      return rethrow(ex);
    }
  }

  public static <R, T1, T2, T3> R wrap(IFunc3<R, T1, T2, T3> func, T1 t1, T2 t2, T3 t3) {
    try {
      return func.apply(t1, t2, t3);
    } catch (Exception ex) {
      return rethrow(ex);
    }
  }
}