android app Search operation with broken words

Hi i am doing a search operation in the app using a specific keyword and listing the result in a list view activity. The result will be displayed with 50 characters before and after the searched keyword but when i take 50 characters it breaks the words and in the result half words or single letters are displayed in the beginning and after. How could i ignore and get 开发者_StackOverflowcomplete words

Below is my code. please do help me on this. thanks in advance

int endindex = searchTextStartIndex + searchTextLength + 50;
            if (searchTextStartIndex > 50) {
                startindex = searchTextStartIndex - 50;
            }
            if (endindex > datalength) {
                endindex = datalength;
            }
            searchdata = searchdata.substring(startindex, endindex);
        } catch (Exception e)

Assuming a space as word seperator:

if (searchTextStartIndex > 50) {
   startindex = searchdata.lastIndexOf( " ", (searchTextStartIndex - 50) );
}

if (startindex == -1) startindex = 0;

int endindex = searchdata.indexOf( " ", (searchTextStartIndex + searchTextLength + 50) );

if (endindex == -1 || endindex > datalength) {
    endindex = datalength;
}

searchdata = searchdata.substring(startindex, endindex);