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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.email.mail.store.imap;
     18 
     19 import com.android.emailcommon.Logging;
     20 
     21 import android.util.Log;
     22 
     23 import java.util.ArrayList;
     24 
     25 /**
     26  * Utility methods for use with IMAP.
     27  */
     28 public class ImapUtility {
     29     /**
     30      * Apply quoting rules per IMAP RFC,
     31      * quoted          = DQUOTE *QUOTED-CHAR DQUOTE
     32      * QUOTED-CHAR     = <any TEXT-CHAR except quoted-specials> / "\" quoted-specials
     33      * quoted-specials = DQUOTE / "\"
     34      *
     35      * This is used primarily for IMAP login, but might be useful elsewhere.
     36      *
     37      * NOTE:  Not very efficient - you may wish to preflight this, or perhaps it should check
     38      * for trouble chars before calling the replace functions.
     39      *
     40      * @param s The string to be quoted.
     41      * @return A copy of the string, having undergone quoting as described above
     42      */
     43     public static String imapQuoted(String s) {
     44 
     45         // First, quote any backslashes by replacing \ with \\
     46         // regex Pattern:  \\    (Java string const = \\\\)
     47         // Substitute:     \\\\  (Java string const = \\\\\\\\)
     48         String result = s.replaceAll("\\\\", "\\\\\\\\");
     49 
     50         // Then, quote any double-quotes by replacing " with \"
     51         // regex Pattern:  "    (Java string const = \")
     52         // Substitute:     \\"  (Java string const = \\\\\")
     53         result = result.replaceAll("\"", "\\\\\"");
     54 
     55         // return string with quotes around it
     56         return "\"" + result + "\"";
     57     }
     58 
     59     /**
     60      * Gets all of the values in a sequence set per RFC 3501. Any ranges are expanded into a
     61      * list of individual numbers. If the set is invalid, an empty array is returned.
     62      * <pre>
     63      * sequence-number = nz-number / "*"
     64      * sequence-range  = sequence-number ":" sequence-number
     65      * sequence-set    = (sequence-number / sequence-range) *("," sequence-set)
     66      * </pre>
     67      */
     68     public static String[] getImapSequenceValues(String set) {
     69         ArrayList<String> list = new ArrayList<String>();
     70         if (set != null) {
     71             String[] setItems = set.split(",");
     72             for (String item : setItems) {
     73                 if (item.indexOf(':') == -1) {
     74                     // simple item
     75                     try {
     76                         Integer.parseInt(item); // Don't need the value; just ensure it's valid
     77                         list.add(item);
     78                     } catch (NumberFormatException e) {
     79                         Log.d(Logging.LOG_TAG, "Invalid UID value", e);
     80                     }
     81                 } else {
     82                     // range
     83                     for (String rangeItem : getImapRangeValues(item)) {
     84                         list.add(rangeItem);
     85                     }
     86                 }
     87             }
     88         }
     89         String[] stringList = new String[list.size()];
     90         return list.toArray(stringList);
     91     }
     92 
     93     /**
     94      * Expand the given number range into a list of individual numbers. If the range is not valid,
     95      * an empty array is returned.
     96      * <pre>
     97      * sequence-number = nz-number / "*"
     98      * sequence-range  = sequence-number ":" sequence-number
     99      * sequence-set    = (sequence-number / sequence-range) *("," sequence-set)
    100      * </pre>
    101      */
    102     public static String[] getImapRangeValues(String range) {
    103         ArrayList<String> list = new ArrayList<String>();
    104         try {
    105             if (range != null) {
    106                 int colonPos = range.indexOf(':');
    107                 if (colonPos > 0) {
    108                     int first  = Integer.parseInt(range.substring(0, colonPos));
    109                     int second = Integer.parseInt(range.substring(colonPos + 1));
    110                     if (first < second) {
    111                         for (int i = first; i <= second; i++) {
    112                             list.add(Integer.toString(i));
    113                         }
    114                     } else {
    115                         for (int i = first; i >= second; i--) {
    116                             list.add(Integer.toString(i));
    117                         }
    118                     }
    119                 }
    120             }
    121         } catch (NumberFormatException e) {
    122             Log.d(Logging.LOG_TAG, "Invalid range value", e);
    123         }
    124         String[] stringList = new String[list.size()];
    125         return list.toArray(stringList);
    126     }
    127 }
    128