| /* |
| * Copyright (C) 2011 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 libcore.net.http; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * @hide |
| */ |
| public final class HeaderParser { |
| |
| public interface CacheControlHandler { |
| void handle(String directive, String parameter); |
| } |
| |
| /** |
| * Parse a comma-separated list of cache control header values. |
| */ |
| public static void parseCacheControl(String value, CacheControlHandler handler) { |
| int pos = 0; |
| while (pos < value.length()) { |
| int tokenStart = pos; |
| pos = skipUntil(value, pos, "=,"); |
| String directive = value.substring(tokenStart, pos).trim(); |
| |
| if (pos == value.length() || value.charAt(pos) == ',') { |
| pos++; // consume ',' (if necessary) |
| handler.handle(directive, null); |
| continue; |
| } |
| |
| pos++; // consume '=' |
| pos = skipWhitespace(value, pos); |
| |
| String parameter; |
| |
| // quoted string |
| if (pos < value.length() && value.charAt(pos) == '\"') { |
| pos++; // consume '"' open quote |
| int parameterStart = pos; |
| pos = skipUntil(value, pos, "\""); |
| parameter = value.substring(parameterStart, pos); |
| pos++; // consume '"' close quote (if necessary) |
| |
| // unquoted string |
| } else { |
| int parameterStart = pos; |
| pos = skipUntil(value, pos, ","); |
| parameter = value.substring(parameterStart, pos).trim(); |
| } |
| |
| handler.handle(directive, parameter); |
| } |
| } |
| |
| /** |
| * Parse RFC 2617 challenges. This API is only interested in the scheme |
| * name and realm. |
| */ |
| public static List<Challenge> parseChallenges( |
| RawHeaders responseHeaders, String challengeHeader) { |
| /* |
| * auth-scheme = token |
| * auth-param = token "=" ( token | quoted-string ) |
| * challenge = auth-scheme 1*SP 1#auth-param |
| * realm = "realm" "=" realm-value |
| * realm-value = quoted-string |
| */ |
| List<Challenge> result = new ArrayList<Challenge>(); |
| for (int h = 0; h < responseHeaders.length(); h++) { |
| if (!challengeHeader.equalsIgnoreCase(responseHeaders.getFieldName(h))) { |
| continue; |
| } |
| String value = responseHeaders.getValue(h); |
| int pos = 0; |
| while (pos < value.length()) { |
| int tokenStart = pos; |
| pos = skipUntil(value, pos, " "); |
| |
| String scheme = value.substring(tokenStart, pos).trim(); |
| pos = skipWhitespace(value, pos); |
| |
| // TODO: This currently only handles schemes with a 'realm' parameter; |
| // It needs to be fixed to handle any scheme and any parameters |
| // http://code.google.com/p/android/issues/detail?id=11140 |
| |
| if (!value.regionMatches(pos, "realm=\"", 0, "realm=\"".length())) { |
| break; // unexpected challenge parameter; give up |
| } |
| |
| pos += "realm=\"".length(); |
| int realmStart = pos; |
| pos = skipUntil(value, pos, "\""); |
| String realm = value.substring(realmStart, pos); |
| pos++; // consume '"' close quote |
| pos = skipUntil(value, pos, ","); |
| pos++; // consume ',' comma |
| pos = skipWhitespace(value, pos); |
| result.add(new Challenge(scheme, realm)); |
| } |
| } |
| return result; |
| } |
| |
| /** |
| * Returns the next index in {@code input} at or after {@code pos} that |
| * contains a character from {@code characters}. Returns the input length if |
| * none of the requested characters can be found. |
| */ |
| private static int skipUntil(String input, int pos, String characters) { |
| for (; pos < input.length(); pos++) { |
| if (characters.indexOf(input.charAt(pos)) != -1) { |
| break; |
| } |
| } |
| return pos; |
| } |
| |
| /** |
| * Returns the next non-whitespace character in {@code input} that is white |
| * space. Result is undefined if input contains newline characters. |
| */ |
| private static int skipWhitespace(String input, int pos) { |
| for (; pos < input.length(); pos++) { |
| char c = input.charAt(pos); |
| if (c != ' ' && c != '\t') { |
| break; |
| } |
| } |
| return pos; |
| } |
| |
| /** |
| * Returns {@code value} as a positive integer, or 0 if it is negative, or |
| * -1 if it cannot be parsed. |
| */ |
| public static int parseSeconds(String value) { |
| try { |
| long seconds = Long.parseLong(value); |
| if (seconds > Integer.MAX_VALUE) { |
| return Integer.MAX_VALUE; |
| } else if (seconds < 0) { |
| return 0; |
| } else { |
| return (int) seconds; |
| } |
| } catch (NumberFormatException e) { |
| return -1; |
| } |
| } |
| } |