加方法

src/main/java/com/egolm/common/HttpUtil.java

@@ -276,6 +276,27 @@ public class HttpUtil {
 		return StringUtil.join("&", params);
 	}
 	
+	public static String formatToQueryStringAndNull(Map<?, ?> parameters) {
+		List<String> params = new ArrayList<String>();
+		if (parameters != null) {
+			for (Object key : parameters.keySet()) {
+				Object val = parameters.get(key);
+				String sKey = String.valueOf(key);
+				Object[] sVals = (val == null ? null : (val instanceof Object[] ? (Object[]) val : (val instanceof Collection<?> ? ((Collection<?>)val).toArray() : new Object[] { val })));
+				if (sVals != null && sVals.length > 0) {
+					for (Object sVal : sVals) {
+						if(StringUtil.isNotEmpty(sVal)) {
+							params.add(sKey + "=" +sVal);
+						} 
+					}
+				}  else {
+					params.add(sKey + "=");  //空值 参与签名  字节跳动
+				} 
+			}
+		}
+		return StringUtil.join("&", params);
+	}
+
 	public static String post(String requestUrl, Map<String, Object> parameters, Map<String, String> headers,
 			Map<String, File> attachments, String contentType) {
 		HttpURLConnection connection = null;