Assert.java

package com.eucalyptus.util;

import java.io.IOException;

/**
 * Assertion utilities.
 */
public final class Assert {
  private Assert() {
  }

  /**
   * @throws IllegalArgumentException when {@code expression} is false
   */
  public static void arg(boolean expression, String errorMessageFormat, Object... args) {
    argNot(!expression, errorMessageFormat, args);
  }

  /**
   * @throws IllegalArgumentException when {@code expression} is false
   */
  public static <T> T arg(T argument, boolean expression, String errorMessageFormat, Object... args) {
    return argNot(argument, !expression, errorMessageFormat, args);
  }

  /**
   * @throws IllegalArgumentException when {@code expression} is true
   */
  public static void argNot(boolean expression, String errorMessageFormat, Object... args) {
    if (expression) {
      throw new IllegalArgumentException(String.format(errorMessageFormat, args));
    }
  }

  /**
   * @throws IllegalArgumentException when {@code argument} is true
   */
  public static <T> T argNot(T argument, boolean expression, String errorMessageFormat, Object... args) {
    argNot(expression, errorMessageFormat, args);
    return argument;
  }

  /**
   * @throws IndexOutOfBoundsException when {@code expression} is false
   */
  public static void index(boolean expression, String errorMessageFormat, Object... args) {
    indexNot(!expression, errorMessageFormat, args);
  }

  /**
   * @throws IndexOutOfBoundsException when {@code expression} is false
   */
  public static void indexNot(boolean expression, String errorMessageFormat, Object... args) {
    if (expression) {
      throw new IndexOutOfBoundsException(String.format(errorMessageFormat, args));
    }
  }

  /**
   * @throws IOException if the {@code expression} is false
   */
  public static void io(boolean expression, String errorMessageFormat, Object... args) throws IOException {
    ioNot(!expression, errorMessageFormat, args);
  }

  /**
   * @throws IOException if the {@code expression} is true
   */
  public static void ioNot(boolean expression, String errorMessageFormat, Object... args) throws IOException {
    if (expression) {
      throw new IOException(String.format(errorMessageFormat, args));
    }
  }

  /**
   * @throws NullPointerException when {@code reference} is null
   */
  public static <T> T notNull(T reference, String parameterName) {
    if (reference == null) {
      throw new NullPointerException(parameterName + " cannot be null");
    }
    return reference;
  }

  /**
   * @throws IllegalStateException when {@code expression} is false
   */
  public static void state(boolean expression, String errorMessageFormat, Object... args) {
    stateNot(!expression, errorMessageFormat, args);
  }

  /**
   * @throws IllegalStateException when {@code expression} is true
   */
  public static void stateNot(boolean expression, String errorMessageFormat, Object... args) {
    if (expression) {
      throw new IllegalStateException(String.format(errorMessageFormat, args));
    }
  }
}