core/src/com/google/inject/internal/util/Strings.java

/**
 * Copyright (C) 2006 Google Inc.
 *
 * 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 com.google.inject.internal.util;

/**
 * String utilities.
 * 
 * @author crazybob@google.com (Bob Lee)
 */
public class Strings {
  private Strings() {}

  /**
   * Returns a string that is equivalent to the specified string with its
   * first character converted to uppercase as by {@link String#toUpperCase}.
   * The returned string will have the same value as the specified string if
   * its first character is non-alphabetic, if its first character is already
   * uppercase, or if the specified string is of length 0.
   *
   * <p>For example:
   * <pre>
   *    capitalize("foo bar").equals("Foo bar");
   *    capitalize("2b or not 2b").equals("2b or not 2b")
   *    capitalize("Foo bar").equals("Foo bar");
   *    capitalize("").equals("");
   * </pre>
   *
   * @param s the string whose first character is to be uppercased
   * @return a string equivalent to <tt>s</tt> with its first character
   *     converted to uppercase
   * @throws NullPointerException if <tt>s</tt> is null
   */
  public static String capitalize(String s) {
    if (s.length() == 0) {
      return s;
    }
    char first = s.charAt(0);
    char capitalized = Character.toUpperCase(first);
    return (first == capitalized)
        ? s
        : capitalized + s.substring(1);
  }
}