代码问题求助解释

[LIDABEN_FIGHTING]

public static String getselect(String name,String tablename,String zdname,String where)
{

String select = "<select name=\""+name+"\" id=\""+name+"\" >";
select+="<option value=\"\">不限</option>";
for(HashMap permap:new CommDAO().select("select * from "+tablename+" where "+where+" order by id desc")){
String optionstr = "";

if(zdname.split(";").length==1){

optionstr=permap.get(zdname.split("~")[0]).toString();


}else{
for(String str:zdname.split(";"))
{
String zdstr = str.split("~")[0];
String zdnamestr = str.split("~")[1].equals("无名")?"":(str.split("~")[1]+":");
optionstr+=zdnamestr+permap.get(zdstr)+" - ";
}
}



if(optionstr.indexOf(" - ")>-1)optionstr=optionstr.substring(0,optionstr.length()-3);
select+="<option value=\""+optionstr+"\">"+optionstr+"</option>";
}
select+="</select>";
return select;
}
请解释一下这部分代码什么意思

[打老虎zz]

拼一段可以在前端创建dom对象的字符串

[我爱娃哈哈]

后端拼接了一个前端可以显示的select组件和数据