Getting URL parameter in java and extract a specific text from that URL

Using pure Java 8

Assumming you want to extract param "v" from url:

             String paramV = Stream.of(url.split("?")[1].split("&"))
                        .map(kv -> kv.split("="))
                        .filter(kv -> "v".equalsIgnoreCase(kv[0]))
                        .map(kv -> kv[1])
                        .findFirst()
                        .orElse("");

I believe we have a better approach to answer this question.

1: Define a function that returns Map values.

Here we go.

public Map<String, String> getUrlValues(String url) throws UnsupportedEncodingException {
    int i = url.indexOf("?");
    Map<String, String> paramsMap = new HashMap<>();
    if (i > -1) {
        String searchURL = url.substring(url.indexOf("?") + 1);
        String params[] = searchURL.split("&");

        for (String param : params) {
            String temp[] = param.split("=");
            paramsMap.put(temp[0], java.net.URLDecoder.decode(temp[1], "UTF-8"));
        }
    }

    return paramsMap;
}

2: Call your function surrounding with a try catch block

Here we go

try {
     Map<String, String> values = getUrlValues("https://example.com/index.php?form_id=9&page=1&view_id=78");
     String formId = values.get("form_id");
     String page = values.get("page");
     String viewId = values.get("view_id");
     Log.d("FormID", formId);
     Log.d("Page", page);
     Log.d("ViewID", viewId);
} catch (UnsupportedEncodingException e) {
     Log.e("Error", e.getMessage());
} 

If you are using Jersey (which I was, my server component needs to make outbound HTTP requests) it contains the following public method:

var multiValueMap = UriComponent.decodeQuery(uri, true);

It is part of org.glassfish.jersey.uri.UriComponent, and the javadoc is here. Whilst you may not want all of Jersey, it is part of the Jersey common package which isn't too bad on dependencies...

I solved the problem like this

public static String getUrlParameterValue(String url, String paramName) {
String value = "";
List<NameValuePair> result = null;

try {
    result = URLEncodedUtils.parse(new URI(url), UTF_8);
    value = result.stream().filter(pair -> pair.getName().equals(paramName)).findFirst().get().getValue();
    System.out.println("-------------->  \n" + paramName + " : " + value + "\n");
} catch (URISyntaxException e) {
    e.printStackTrace();
} 
return value;

}

public static String getQueryMap(String query) {        
    String[] params = query.split("&");     
    for (String param : params) {           
       String name = param.split("=")[0];
       if ("YourParam".equals(name)) {
           return param.split("=")[1]; 
       }
    }
    return null;
}