split String by space separated

Question

I need to split words by space separated in java, so I have used .split function in-order to achieve that like as shown below

String keyword = "apple mango ";
String keywords [] = keyword .split(" ");

The above code is working fine but the only is that I sometimes my keyword will contain keyword like "jack fruit" , "ice cream" with double quotes like as shown below

String keyword = "apple mango \"jack fruit\" \"ice cream\"";

In this case I need to get 4 words like apple, mango, jack fruit, ice cream in keywords array

Can anyone please tell me some solution for this

Answer 1

List<String> parts = new ArrayList<>();
String keyword = "apple mango \"jack fruit\" \"ice cream\"";

// first use a matcher to grab the quoted terms
Pattern p = Pattern.compile("\"(.*?)\"");      
Matcher m = p.matcher(keyword);
while (m.find()) {
    parts.add(m.group(1));
}

// then remove all quoted terms (quotes included)
keyword = keyword.replaceAll("\".*?\"", "")
                 .trim();

// finally split the remaining keywords on whitespace
if (keyword.replaceAll("\\s", "").length() > 0) {
    Collections.addAll(parts, keyword.split("\\s+"));
}

for (String part : parts) {
    System.out.println(part);
}

Output:

jack fruit
ice cream
apple
mango

Answer 2

This solution works but i am sure that is not the best for performance / resources. It also works when you have fruits with more than two words. Feel free to edit or optimize my code.

public static void main(String[] args) {
        String keyword = "apple mango \"jack fruit\" \"ice cream\" \"one two three\"";
        String[] split = custom_split(keyword);
        for (String s : split) {
            System.out.println(s);
        }
    }

    private static String[] custom_split(String keyword) {
        String[] split = keyword.split(" ");
        ArrayList<String> list = new ArrayList<>();
        StringBuilder temp = new StringBuilder();
        boolean multiple = false;
        for (String s : split) {
            if (s.startsWith("\"")) {
                multiple = true;
                s = s.replaceAll("\"", "");
                temp.append(s);
                continue;
            }
            if (s.endsWith("\"")) {
                multiple = false;
                s = s.replaceAll("\"", "");
                temp.append(" ").append(s);
                list.add(temp.toString());
                temp = new StringBuilder();
                continue;
            }
            if (multiple) {
                temp.append(" ").append(s);
            } else {
                list.add(s);
            }
        }
        String[] result = new String[list.size()];
        for (int i = 0; i < list.size(); i++) {
            result[i] = list.get(i);
        }
        return result;
    }

Answer 3

You can't do that with String.split(). You need to come up with a regular expression for the target tokens, and collect them through a matcher, like this:

    final Pattern token = Pattern.compile( "[^\"\\s]+|\"[^\"]*\"" );

    List<String> tokens = new ArrayList<>();
    Matcher m = token.matcher( "apple mango \"jack fruit\" \"ice cream\"" );
    while( m.find() )
        tokens.add( m.group() );

Answer 4

I'd do it with a regex and two capturing group, one for each pattern. I'm not aware of any other way.

    String keyword = "apple mango \"jack fruit\" \"ice cream\"";
    Pattern p = Pattern.compile("\"?(\\w+\\W+\\w+)\"|(\\w+)");      
    Matcher m = p.matcher(keyword);
    while (m.find()) {
        String word = m.group(1) == null ? m.group(2) : m.group(1);
        System.out.println(word);
    }

Answer 5

This will split string on quotes, and then additionally split even members by spaces.

    String keyword = "apple mango \"jack fruit\" \"ice cream\"";
    String splitQuotes [] = keyword.split("\"");

    List<String> keywords = new ArrayList<>();

    for (int i = 0; i < splitQuotes.length; i++) {
        if (i % 2 == 0) {
            Collections.addAll(keywords, splitQuotes[i].split(" "));
        } else {
            keywords.add(splitQuotes[i]);
        }
    }