2 ways to convert Java Map to String

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

public class MapUtil {
 public static String mapToString(Map<String, String> map) {
   StringBuilder stringBuilder = new StringBuilder();

   for (String key : map.keySet()) {
    if (stringBuilder.length() > 0) {
     stringBuilder.append("&");
    }
    String value = map.get(key);
    try {
     stringBuilder.append((key != null ? URLEncoder.encode(key, "UTF-8") : ""));
     stringBuilder.append("=");
     stringBuilder.append(value != null ? URLEncoder.encode(value, "UTF-8") : "");
    } catch (UnsupportedEncodingException e) {
     throw new RuntimeException("This method requires UTF-8 encoding support", e);
    }
   }

   return stringBuilder.toString();
  }

  public static Map<String, String> stringToMap(String input) {
   Map<String, String> map = new HashMap<String, String>();

   String[] nameValuePairs = input.split("&");
   for (String nameValuePair : nameValuePairs) {
    String[] nameValue = nameValuePair.split("=");
    try {
     map.put(URLDecoder.decode(nameValue[0], "UTF-8"), nameValue.length > 1 ? URLDecoder.decode(
     nameValue[1], "UTF-8") : "");
    } catch (UnsupportedEncodingException e) {
     throw new RuntimeException("This method requires UTF-8 encoding support", e);
    }
   }

   return map;
  }
}