java/com/android/dialer/util/MoreStrings.java

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * 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.android.dialer.util;

import android.support.annotation.Nullable;
import android.text.TextUtils;

/** Static utility methods for Strings. */
public class MoreStrings {

  /**
   * Returns the given string if it is non-null; the empty string otherwise.
   *
   * @param string the string to test and possibly return
   * @return {@code string} itself if it is non-null; {@code ""} if it is null
   */
  public static String nullToEmpty(@Nullable String string) {
    return (string == null) ? "" : string;
  }

  /**
   * Returns the given string if it is nonempty; {@code null} otherwise.
   *
   * @param string the string to test and possibly return
   * @return {@code string} itself if it is nonempty; {@code null} if it is empty or null
   */
  @Nullable
  public static String emptyToNull(@Nullable String string) {
    return TextUtils.isEmpty(string) ? null : string;
  }

  public static String toSafeString(String value) {
    if (value == null) {
      return null;
    }

    // Do exactly same thing as Uri#toSafeString() does, which will enable us to compare
    // sanitized phone numbers.
    final StringBuilder builder = new StringBuilder();
    for (int i = 0; i < value.length(); i++) {
      final char c = value.charAt(i);
      if (c == '-' || c == '@' || c == '.') {
        builder.append(c);
      } else {
        builder.append('x');
      }
    }
    return builder.toString();
  }
}