public String join(String separator, final String keyValueSeparator) {
		return MapUtil.join(this.map, separator, keyValueSeparator);
	}
public String join ( String separator , final String keyValueSeparator ) { return MapUtil . join ( this . map , separator , keyValueSeparator ) ; }
将map转成字符串

@param separator entry之间的连接符
@param keyValueSeparator kv之间的连接符
@return 连接字符串