The current implementation of subword completion [1] leads to PatternSyntaxException in the java editor, when you try to codecomplete in a string with contains a reserved regex token.

For example: Code complete within the following literals
<code>
            String a="{}";
            String b="()";
            String c="?";
            String d="+";
</code>

ACTUAL: 
PatternSyntaxException 

Example for the first code line 
java.util.regex.PatternSyntaxException: Illegal repetition near index 6
.*?".*?{.*?
      ^

EXPECTED:
No exception, subword code completion works


[1] https://netbeans.org/bugzilla/show_bug.cgi?id=212412

FYI: Set to P2, because it is unusable.