Strings.java

package pl.project13.janbanery.android.util;

import java.io.*;
import java.security.InvalidParameterException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.*;

/**
 * This is a subset of the Strings class available in <strong>RoboGuice</strong>.
 * It's licensed under the Apache License 2.0.
 *
 * @see <a href="http://code.google.com/p/roboguice/source/browse/roboguice/src/main/java/roboguice/util/Strings.java">http://code.google.com/p/roboguice</a>
 */
public class Strings {
  private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

  /**
   * Like join, but allows for a distinct final delimiter.  For english sentences such
   * as "Alice, Bob and Charlie" use ", " and " and " as the delimiters.
   *
   * @param delimiter     usually ", "
   * @param lastDelimiter usually " and "
   * @param objs          the objects
   * @param <T>           the type
   * @return a string
   */
  public static <T> String joinAnd(final String delimiter, final String lastDelimiter, final Collection<T> objs) {
    if (objs == null || objs.isEmpty()) {
      return "";
    }

    final Iterator<T> iter = objs.iterator();
    final StringBuffer buffer = new StringBuffer(Strings.toString(iter.next()));
    int i = 1;
    while (iter.hasNext()) {
      final T obj = iter.next();
      if (notEmpty(obj)) {
        buffer.append(++i == objs.size() ? lastDelimiter : delimiter).append(Strings.toString(obj));
      }
    }
    return buffer.toString();
  }

  public static <T> String joinAnd(final String delimiter, final String lastDelimiter, final T... objs) {
    return joinAnd(delimiter, lastDelimiter, Arrays.asList(objs));
  }

  public static <T> String join(final String delimiter, final Collection<T> objs) {
    if (objs == null || objs.isEmpty()) {
      return "";
    }

    final Iterator<T> iter = objs.iterator();
    final StringBuffer buffer = new StringBuffer(Strings.toString(iter.next()));

    while (iter.hasNext()) {
      final T obj = iter.next();
      if (notEmpty(obj)) {
        buffer.append(delimiter).append(Strings.toString(obj));
      }
    }
    return buffer.toString();
  }

  public static <T> String join(final String delimiter, final T... objects) {
    return join(delimiter, Arrays.asList(objects));
  }

  public static String toString(InputStream input) {
    StringWriter sw = new StringWriter();
    copy(new InputStreamReader(input), sw);
    return sw.toString();
  }

  public static String toString(Reader input) {
    StringWriter sw = new StringWriter();
    copy(input, sw);
    return sw.toString();
  }

  public static int copy(Reader input, Writer output) {
    long count = copyLarge(input, output);
    return count > Integer.MAX_VALUE ? -1 : (int) count;
  }

  public static long copyLarge(Reader input, Writer output) throws RuntimeException {
    try {
      char[] buffer = new char[DEFAULT_BUFFER_SIZE];
      long count = 0;
      int n;
      while (-1 != (n = input.read(buffer))) {
        output.write(buffer, 0, n);
        count += n;
      }
      return count;
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  public static String toString(final Object o) {
    return toString(o, "");
  }

  public static String toString(final Object o, final String def) {
    return o == null ? def :
        o instanceof InputStream ? toString((InputStream) o) :
            o instanceof Reader ? toString((Reader) o) :
                o instanceof Object[] ? Strings.join(", ", (Object[]) o) :
                    o instanceof Collection ? Strings.join(", ", (Collection<?>) o) : o.toString();
  }

  public static boolean isEmpty(final Object o) {
    return toString(o).trim().length() == 0;
  }

  public static boolean notEmpty(final Object o) {
    return toString(o).trim().length() != 0;
  }

  public static String md5(String s) {
    try {
      // Create MD5 Hash
      final MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
      digest.update(s.getBytes());
      final byte messageDigest[] = digest.digest();

      // Create Hex String
      final StringBuffer hexString = new StringBuffer();
      for (byte aMessageDigest : messageDigest) {
        hexString.append(Integer.toHexString(0xFF & aMessageDigest));
      }
      return hexString.toString();

    } catch (NoSuchAlgorithmException e) {
      throw new RuntimeException(e);
    }
  }

  public static String capitalize(String s) {
    final String c = Strings.toString(s);
    return c.length() >= 2 ? c.substring(0, 1).toUpperCase() + c.substring(1) : c.length() >= 1 ? c.toUpperCase() : c;
  }

  public static boolean equals(Object a, Object b) {
    return Strings.toString(a).equals(Strings.toString(b));
  }

  public static boolean equalsIgnoreCase(Object a, Object b) {
    return Strings.toString(a).toLowerCase().equals(Strings.toString(b).toLowerCase());
  }

  public static String[] chunk(String str, int chunkSize) {
    if (isEmpty(str) || chunkSize == 0) {
      return new String[0];
    }

    final int len = str.length();
    final int arrayLen = ((len - 1) / chunkSize) + 1;
    final String[] array = new String[arrayLen];
    for (int i = 0; i < arrayLen; ++i) {
      array[i] = str.substring(i * chunkSize, (i * chunkSize) + chunkSize < len ? (i * chunkSize) + chunkSize : len);
    }

    return array;
  }

  public static String namedFormat(String str, Map<String, String> substitutions) {
    for (String key : substitutions.keySet()) {
      str = str.replace('$' + key, substitutions.get(key));
    }

    return str;
  }

  public static String namedFormat(String str, Object... nameValuePairs) {
    if (nameValuePairs.length % 2 != 0) {
      throw new InvalidParameterException("You must include one value for each parameter");
    }

    final HashMap<String, String> map = new HashMap<String, String>(nameValuePairs.length / 2);
    for (int i = 0; i < nameValuePairs.length; i += 2) {
      map.put(Strings.toString(nameValuePairs[i]), Strings.toString(nameValuePairs[i + 1]));
    }

    return namedFormat(str, map);
  }

}