1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.chemistry.opencmis.server.support.query;
20
21
22 public class StringUtil {
23
24 /**
25 * remove all escape sequences in a string and return unescaped string
26 * escape character is backslash \, so \\ --> \, \' --> ' additional
27 * escaped characters can be allowed in escapedChars
28 * @param literal
29 * String to unescape
30 * @param escapedChars
31 * set of allowed characters to be escaped with a backslash, if set to
32 * null then ' (quote) and \ (backslash) are allowed to be escaped
33 * @return
34 * unescaped literal or null if the literal is illegal
35 */
36 public static String unescape(String literal, String escapedChars) {
37 char c ='?';
38 int i=0;
39 StringBuffer sb = new StringBuffer();
40
41 if (null == escapedChars)
42 escapedChars = "\\'";
43
44 if (null == literal)
45 return null;
46
47 int len = literal.length();
48
49 if (len == 1 && literal.charAt(0) == '\\')
50 return null;
51
52 if (len > 1 && literal.charAt(len-2) != '\\' && literal.charAt(len-1) == '\\')
53 return null;
54
55 for (i=0; i<len; i++) {
56 c = literal.charAt(i);
57 if ( c == '\\') {
58 char escChar = literal.charAt(i+1);
59 boolean matched = false;
60 for (int j = 0; j< escapedChars.length(); j++) {
61 if (escChar == escapedChars.charAt(j)) {
62 sb.append(escChar);
63 ++i;
64 matched = true;
65 break;
66 }
67 }
68
69 if (!matched)
70 return null;
71
72 } else {
73 sb.append(literal.charAt(i));
74 }
75 }
76
77 return sb.toString();
78 }
79
80 }