How to escape all Special Characters from whole string at one go in Java

Question

Lucene supports escaping special characters that are part of the query syntax. The current list special characters are

+ - && || ! ( ) { } [ ] ^ " ~ * ? : \

To escape these character use the \ before the character. For example to search for (1+1):2 use the query:

\(1\+1\)\:2

My question is how to escape from whole string at one go? For example myStringToEscape = "ABC^ " ~ * ? :DEF"; How to get a escapedString.

Answer 1

You can use QueryParser.escape, such as:

String escapedString = queryParser.escape(searchString);
queryParser.parse("field:" + escapedString);

Answer 2

If you are just looking for simple replacement, this will do the trick.

String regex = "([+\\-!\\(\\){}\\[\\]^\"~*?:\\\\]|[&\\|]{2})";

String myStringToEscape = "ABC^ \" ~ * ? :DEF";
String myEscapedString = myStringToEscape.replaceAll(regex, "\\\\$1");

System.out.println(myEscapedString);

This will output:

ABC\^ \" \~ \* \? \:DEF