Map< string,? String & gt? sortMap？ =? New? Tree diagram & lt string,? String & gt ();

sort map . putall(params)；

//? Use k1= v1&; K2=v2 ... Mode stitching parameters

StringBuilder？ A builder? =? New? StringBuilder()；

For what? (figure. Entry & lt string,? String & gt? s？ :? sortMap.entrySet())？ {

String? k？ =? s . getkey()；

String? v？ =? s . getvalue()；

What if? (StringUtils.isBlank(v))？ {//? Filter null value

Continue;

}

builder.append(k)。 Append ("="). Add (v). Add&;

}

What if? (! sortMap.isEmpty())？ {

builder . delete charat(builder . length()？ -? 1);

}

Return? MD 5 util . MD 5 encode(builder . tostring())。 toupper case()；

} Put all the parameters into treeMap (default ascending order), then splice them circularly and encrypt them with md5.