Extract util methods to separate classes

src/main/java/org/asamk/signal/util/Util.java

@@ -1,10 +1,56 @@
 package org.asamk.signal.util;
 
-import java.io.File;
-import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.net.URLDecoder;
+import java.util.HashMap;
+import java.util.Map;
 
 public class Util {
-    public static File createTempFile() throws IOException {
-        return File.createTempFile("signal_tmp_", ".tmp");
+
+    private Util() {
+    }
+
+    public static String formatSafetyNumber(String digits) {
+        final int partCount = 12;
+        int partSize = digits.length() / partCount;
+        StringBuilder f = new StringBuilder(digits.length() + partCount);
+        for (int i = 0; i < partCount; i++) {
+            f.append(digits, i * partSize, (i * partSize) + partSize).append(" ");
+        }
+        return f.toString();
+    }
+
+    public static Map<String, String> getQueryMap(String query) {
+        String[] params = query.split("&");
+        Map<String, String> map = new HashMap<>();
+        for (String param : params) {
+            String name = null;
+            final String[] paramParts = param.split("=");
+            try {
+                name = URLDecoder.decode(paramParts[0], "utf-8");
+            } catch (UnsupportedEncodingException e) {
+                // Impossible
+            }
+            String value = null;
+            try {
+                value = URLDecoder.decode(paramParts[1], "utf-8");
+            } catch (UnsupportedEncodingException e) {
+                // Impossible
+            }
+            map.put(name, value);
+        }
+        return map;
+    }
+
+    public static String join(CharSequence separator, Iterable<? extends CharSequence> list) {
+        StringBuilder buf = new StringBuilder();
+        for (CharSequence str : list) {
+            if (buf.length() > 0) {
+                buf.append(separator);
+            }
+            buf.append(str);
+        }
+
+        return buf.toString();
     }
 }