SWT table filter with special characters

Question

Hi I am adding a column level filter to a tableviewer, which will have special characters in the column being filtered. That column will contain xpath string as data, which obviously will contain special characters like the below,

xpath=//a[@name='panels:swappableContent:toggleButton']/span[@class='standardized-icon expandIcon']

I have created a filter object, code is given below,

public class ObjectLocatorFilter extends ViewerFilter {

    private String searchString;

    public void setSearchText(String string) {
        // ensure that the value can be used for matching
        this.searchString = ".*" + string + ".*";
    }

    @Override
    public boolean select(Viewer viewer, Object parentElement, Object element) {

        if(searchString == null || searchString.length() == 0){
            return true;
        }

        Element elem = (Element) element;

        if(elem.getObjectLocator().matches(searchString)){
            return true;
        }

        return false;
    }
}

and added the filter to the table viewer, using the below code,

objectLocatorFilter = new ObjectLocatorFilter();                
tableViewerPageObjects.addFilter(objectLocatorFilter);
tableViewerPageObjects.refresh();

but when tried to search with text like [@class='', it results with below exception,

java.util.regex.PatternSyntaxException: Unclosed character class near index 13
.*[@class=''.*
         ^
at java.util.regex.Pattern.error(Pattern.java:1955)
at java.util.regex.Pattern.clazz(Pattern.java:2548)

Pls guide me on how to add resolve this issue. thanks in advance.

Answer 1

If you don't want Pattern to handle special characters in your search string you must quote it:

this.searchString = ".*" + Pattern.quote(string) + ".*";

But since you are just looking for the search string in the element you don't really need a regular expression at all. Just use the contains method of String:

if (stringToSearch.contains(stringToFind)) {
   ....
}