I\'ve got the URI like this:
https://google.com.ua/oauth/authorize?client_id=SS&response_type=code&scope=N_FULL&access_type=offline&redirect_
On Android, there is a Uri class in package android.net . Note that Uri is part of android.net, while URI is part of java.net .
Uri class has many functions to extract key-value pairs from a query.
Following function returns key-value pairs in the form of HashMap.
In Java:
Map<String, String> getQueryKeyValueMap(Uri uri){
HashMap<String, String> keyValueMap = new HashMap();
String key;
String value;
Set<String> keyNamesList = uri.getQueryParameterNames();
Iterator iterator = keyNamesList.iterator();
while (iterator.hasNext()){
key = (String) iterator.next();
value = uri.getQueryParameter(key);
keyValueMap.put(key, value);
}
return keyValueMap;
}
In Kotlin:
fun getQueryKeyValueMap(uri: Uri): HashMap<String, String> {
val keyValueMap = HashMap<String, String>()
var key: String
var value: String
val keyNamesList = uri.queryParameterNames
val iterator = keyNamesList.iterator()
while (iterator.hasNext()) {
key = iterator.next() as String
value = uri.getQueryParameter(key) as String
keyValueMap.put(key, value)
}
return keyValueMap
}
If you are using Spring, add an argument of type @RequestParam Map<String,String>
to your controller method, and Spring will construct the map for you!
Just an update to the Java 8 version
public Map<String, List<String>> splitQuery(URL url) {
if (Strings.isNullOrEmpty(url.getQuery())) {
return Collections.emptyMap();
}
return Arrays.stream(url.getQuery().split("&"))
.map(this::splitQueryParameter)
.collect(Collectors.groupingBy(SimpleImmutableEntry::getKey, LinkedHashMap::new, **Collectors**.mapping(Map.Entry::getValue, **Collectors**.toList())));
}
mapping and toList() methods have to be used with Collectors which was not mentioned in the top answer. Otherwise it would throw compilation error in IDE
Netty also provides a nice query string parser called QueryStringDecoder
.
In one line of code, it can parse the URL in the question.
I like because it doesn't require catching or throwing java.net.MalformedURLException
.
In one line:
Map<String, List<String>> parameters = new QueryStringDecoder(url).parameters();
See javadocs here: https://netty.io/4.1/api/io/netty/handler/codec/http/QueryStringDecoder.html
Here is a short, self contained, correct example:
import io.netty.handler.codec.http.QueryStringDecoder;
import org.apache.commons.lang3.StringUtils;
import java.util.List;
import java.util.Map;
public class UrlParse {
public static void main(String... args) {
String url = "https://google.com.ua/oauth/authorize?client_id=SS&response_type=code&scope=N_FULL&access_type=offline&redirect_uri=http://localhost/Callback";
QueryStringDecoder decoder = new QueryStringDecoder(url);
Map<String, List<String>> parameters = decoder.parameters();
print(parameters);
}
private static void print(final Map<String, List<String>> parameters) {
System.out.println("NAME VALUE");
System.out.println("------------------------");
parameters.forEach((key, values) ->
values.forEach(val ->
System.out.println(StringUtils.rightPad(key, 19) + val)));
}
}
which generates
NAME VALUE
------------------------
client_id SS
response_type code
scope N_FULL
access_type offline
redirect_uri http://localhost/Callback
If you're using Java 8 and you're willing to write a few reusable methods, you can do it in one line.
private Map<String, List<String>> parse(final String query) {
return Arrays.asList(query.split("&")).stream().map(p -> p.split("=")).collect(Collectors.toMap(s -> decode(index(s, 0)), s -> Arrays.asList(decode(index(s, 1))), this::mergeLists));
}
private <T> List<T> mergeLists(final List<T> l1, final List<T> l2) {
List<T> list = new ArrayList<>();
list.addAll(l1);
list.addAll(l2);
return list;
}
private static <T> T index(final T[] array, final int index) {
return index >= array.length ? null : array[index];
}
private static String decode(final String encoded) {
try {
return encoded == null ? null : URLDecoder.decode(encoded, "UTF-8");
} catch(final UnsupportedEncodingException e) {
throw new RuntimeException("Impossible: UTF-8 is a required encoding", e);
}
}
But that's a pretty brutal line.
The shortest way I've found is this one:
MultiValueMap<String, String> queryParams =
UriComponentsBuilder.fromUriString(url).build().getQueryParams();
UPDATE: UriComponentsBuilder
comes from Spring. Here the link.