Java tutorial
//package com.java2s; import java.util.Collections; import java.util.LinkedHashSet; import java.util.Set; import android.net.Uri; public class Main { private static Set<String> getQueryParameterNames(Uri uri) { if (uri.isOpaque()) { throw new UnsupportedOperationException("This isn't a hierarchical URI."); } String query = uri.getEncodedQuery(); if (query == null) { return Collections.emptySet(); } Set<String> names = new LinkedHashSet<String>(); int start = 0; do { int next = query.indexOf('&', start); int end = (next == -1) ? query.length() : next; int separator = query.indexOf('=', start); if (separator > end || separator == -1) { separator = end; } String name = query.substring(start, separator); names.add(Uri.decode(name)); // Move start to end of name. start = end + 1; } while (start < query.length()); return Collections.unmodifiableSet(names); } }