android/guava/src/com/google/common/primitives/ParseRequest.java

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * 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.common.primitives;

import com.google.common.annotations.GwtCompatible;

/** A string to be parsed as a number and the radix to interpret it in. */
@GwtCompatible
final class ParseRequest {
  final String rawValue;
  final int radix;

  private ParseRequest(String rawValue, int radix) {
    this.rawValue = rawValue;
    this.radix = radix;
  }

  static ParseRequest fromString(String stringValue) {
    if (stringValue.length() == 0) {
      throw new NumberFormatException("empty string");
    }

    // Handle radix specifier if present
    String rawValue;
    int radix;
    char firstChar = stringValue.charAt(0);
    if (stringValue.startsWith("0x") || stringValue.startsWith("0X")) {
      rawValue = stringValue.substring(2);
      radix = 16;
    } else if (firstChar == '#') {
      rawValue = stringValue.substring(1);
      radix = 16;
    } else if (firstChar == '0' && stringValue.length() > 1) {
      rawValue = stringValue.substring(1);
      radix = 8;
    } else {
      rawValue = stringValue;
      radix = 10;
    }

    return new ParseRequest(rawValue, radix);
  }
}