solr系统query检索词特殊字符的处理

solr是基于 lucence开发的应用，如果query中带有非法字符串，结果很可能是检索出所有内容或者直接报错，所以你对用户的输入必须要先做处理。输入星号，能够检索出所有内容；输入加号，则会报错。

官方的处理办法（java，因为solr是java开发的）：

1. https://svn.apache.org/repos/asf/lucene/dev/trunk/solr/solrj/src/java/org/apache/solr/client/solrj/util/ClientUtils.java
2.  
3. public static String escapeQueryChars(String s) {
4. StringBuilder sb = new StringBuilder();
5. for (int i = 0; i < s.length(); i++) {
6. char c = s.charAt(i);
7. // These characters are part of the query syntax and must be escaped
8. if (c == '\\' || c == '+' || c == '-' || c == '!' || c == '(' || c == ')' || c == ':'
9. || c == '^' || c == '[' || c == ']' || c == '\"' || c == '{' || c == '}' || c == '~'
10. || c == '*' || c == '?' || c == '|' || c == '&' || c == ';' || c == '/'
11. || Character.isWhitespace(c)) {
12. sb.append('\\');
13. }
14. sb.append(c);
15. }
16. return sb.toString();
17. }

翻译的php版本（利用preg_replace函数进行正则替换）：

1. static public function escape($value)
2. {
3. //list taken from http://lucene.apache.org/java/docs/queryparsersyntax.html#Escaping%20Special%20Characters
4. $pattern = '/(\+|-|&|\||!|\(|\)|\{|}|\[|]|\^|"|~|\*|\?|:|;|~|\/)/';
5. $replace = '\\\$1';
6.  
7. return preg_replace($pattern, $replace, $value);
8. }

翻译后的python版本：

1. import re
2. def escape_solr(word):
3. return re.sub('(\\\|\+|-|&|\|\||!|\(|\)|\{|}|\[|]|\^|"|~|\*|\?|:|;|/|\~)','\\\1', word )

C#版

    /// <summary>
    /// solr查询字符串特殊字符转义
    /// </summary>
    /// <param name="s"></param>
    /// <returns></returns>
    public static String escapeQueryChars(String s)
    {
        StringBuilder sb = new StringBuilder();
        var ss = s.ToCharArray();
        foreach (var c in ss)
        {
            // These characters are part of the query syntax and must be escaped
            if (c == '\\' || c == '+' || c == '-' || c == '!' || c == '(' || c == ')' || c == ':'
              || c == '^' || c == '[' || c == ']' || c == '\"' || c == '{' || c == '}' || c == '~'
              || c == '*' || c == '?' || c == '|' || c == '&' || c == ';' || c == '/'
              )
            {
                sb.Append('\\');
            }
            sb.Append(c);
        }
        return sb.ToString();
    }