Question

String input = "key1=value1&key2=value2&key3=value3&key4=value4&key5=value5";

How can I store the key-value pairs into a HashMap object using StringTokenizer?

Answer 1

Using a StringTokenizer would look something like this I guess.

String input = "key1=value1&key2=value2&key3=value3&key4=value4&key5=value5";
StringTokenizer st = new StringTokenizer(input, "&");

Map<String, String> map = new HashMap<String, String>();

while ( st.hasMoreElements() ) {

    String actualElement = st.nextToken();
    StringTokenizer et = new StringTokenizer(actualElement, "=");

    if ( et.countTokens() != 2 ) {
        throw new RuntimeException("Unexpeced format");
    }

    String key = et.nextToken();
    String value = et.nextToken();

    map.put(key, value);
}

System.out.println(map);

You could also use String.split(). It looks a little nicer in my opinion.

Map<String, String> map = new HashMap<String, String>();

for ( String actualElement : input.split("&") ) {
    map.put(actualElement.split("=")[0],
            actualElement.split("=")[1]);
}

System.out.println(map);

Beware that you must make sure that the delimiters (in this case “=” and “&”) is not allowed to appear in the data! When the delimiters should be allowed to appear in the data they must be escaped in some way to handle the input properly.