How to parse the string into map

Question

have a string like A=B&C=D&E=F, how to parse it into map?

Answer 1

I would use split

String text = "A=B&C=D&E=F";
Map<String, String> map = new LinkedHashMap<String, String>();
for(String keyValue : text.split(" *& *")) {
   String[] pairs = keyValue.split(" *= *", 2);
   map.put(pairs[0], pairs.length == 1 ? "" : pairs[1]);
}

EDIT allows for padded spaces and a value with an = or no value. e.g.

A = minus- & C=equals= & E==F

Answer 2

just use guava Splitter

String src="A=B&C=D&E=F";
Map map= Splitter.on('&').withKeyValueSeparator('=').split(src)；

Answer 3

public class TestMapParser {
    @Test
    public void testParsing() {
        Map<String, String> map = parseMap("A=B&C=D&E=F");
        Assert.assertTrue("contains key", map.containsKey("A"));
        Assert.assertEquals("contains value", "B", map.get("A"));

        Assert.assertTrue("contains key", map.containsKey("C"));
        Assert.assertEquals("contains value", "D", map.get("C"));

        Assert.assertTrue("contains key", map.containsKey("E"));
        Assert.assertEquals("contains value", "F", map.get("E"));
    }

    private Map<String, String> parseMap(final String input) {
        final Map<String, String> map = new HashMap<String, String>();
        for (String pair : input.split("&")) {
            String[] kv = pair.split("=");
            map.put(kv[0], kv[1]);
        }
        return map;
    }
}

Answer 4

Split the string (either using a StringTokenizer or String.split()) on '&'. On each token just split again on '='. Use the first part as the key and the second part as the value.

It can also be done using a regex, but the problem is really simple enough for StringTokenizer.

Answer 5

String  t = A=B&C=D&E=F;
Map map = new HashMap();
String[] pairs = t.split("&");
//TODO 1) Learn generis 2) Use gnerics    
for (String pair : pairs)
{
    String[] kv = pair.split("=");
    map.put(kv[0], kv[1]);
}