Util.java :  » App » microsleep » org » microsleep » Android Open Source

package org.microsleep;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

public class Util {

  public static <OUT, IN> Collection<OUT> map(Collection<IN> list,
      F<IN, OUT> f) {
    Collection<OUT> result = new ArrayList<OUT>(list.size());
    for (IN item : list) {
      result.add(f.f(item));
    }
    return result;
  }

  public static String concat(Collection<String> list, String separator) {
    StringBuilder builder = new StringBuilder();
    Iterator<String> i = list.iterator();
    if (i.hasNext()) {
      builder.append(i.next());
    }
    while (i.hasNext()) {
      builder.append(separator);
      builder.append(i.next());
    }
    return builder.toString();
  }

  public static void notNull(Object arg) {
    if (arg == null) {
      throw new IllegalArgumentException("Parameter is null");
    }
  }

  public static void notNull(Object arg, String message) {
    if (arg == null) {
      throw new IllegalArgumentException(message);
    }
  }

  public static void isTrue(boolean condition, String message) {
    if (!condition) {
      if (message == null) {
        message = "Condition was not met";
      }
      throw new IllegalArgumentException(message);
    }
  }

  public interface F<IN, OUT> {
    public OUT f(IN in);
  }
}