java - How to bind String[] to Collection of POJOs? -

i have binder gets string of permissions , must convert collection. when binder method invoking can’t convert array of string collection.

my controller:

@controller @requestmapping("/profile") public class profilecontroller {     @autowired     @qualifier("mvcuserservice")     userservice userservice;      @requestmapping(value = "/edit", method = requestmethod.get)     public modelandview editform(principal principal) {         user user = userservice.getuser(principal.getname());         modelandview mav = new modelandview("user/profile");         return mav.addobject("user", user);     }      @requestmapping(value = "/edit", method = requestmethod.put)     public modelandview edit(@modelattribute("user") user user, bindingresult result) {         // action user object     }      @initbinder     public void initbinder(webdatabinder binder) {         binder.registercustomeditor(permission.class, new propertyeditorsupport() {             @override             public void setastext(string name) throws illegalargumentexception {                 permission permission = userservice.getpermission(name);                 setvalue(permission);             }         }); 

jsp:

<form:form action="/profile/edit" method="put" modelattribute="user"> <input type="hidden" name="_method" value="put"/>  // setting fields  <form:hidden path="id"/> <form:hidden path="permissions"/> </form:form> 

permission class:

public class permission implements serializable {     private integer id;     private string name; 

and user class:

public class user implements serializable {      // fields      private collection<permission> permissions; 

i need implement correct binding. suggestions how can it?

your editor seems lack logic convert csv list list of objects. here code permissionlisteditor convert comma-separated list of strings to/from list collection:

public class permissionlisteditor extends propertyeditorsupport {    @override   public void setastext(string text) throws illegalargumentexception {     list<permission> res = new arraylist();     (string v: text.split(",")) {       if (v.trim().length() > 0)         res.add(userservice.getpermission(v.trim()));     }     setvalue(res);   }    @override   public string getastext() {     stringbuilder val = new stringbuilder();     (permission p: (list<permission>) getvalue()) {       if (val.length() > 0) val.append(", ");       val.append(p.getname());     }     return val.tostring();   }  } 

it idea add sort of map lookup permission objects instead of fetching them database one-by one. in constructor:

map<string, permission> map = new hashmap()<>; (permission p: userservice.listpermissions();   map.add(p.getname(), p); 

and retrieve objects map in setastext() method:

res.add(map.get(v.trim()); 

hope helps.