java ee - JSF 2.3 Custom converter with generics -

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we started use jsf 2.3 on our existing jsf 2.2 project. on our custom converters got warning converter raw type. references generic type converter<t> should parameterized. problem experiencing when tried fix warning using generics:

@facesconverter(value = "myconverter", managed = true) public class myconverter implements converter<mycustomobject>{    @override public mycustomobject getasobject(facescontext context, uicomponent component, string submittedvalue){}  @override public string getasstring(facescontext context, uicomponent component, mycustomobject modelvalue) {} }

and when converter used example in 

<!doctype html> <ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:c="http://xmlns.jcp.org/jsp/jstl/core" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:ui="http://java.sun.com/jsf/facelets"> <h:selectonemenu id="#{componentid}" value="#{componentvalue}">     <f:converter converterid="myconverter" />     <f:selectitem itemlabel="label"         itemvalue="" />     <f:selectitems value="listofvalues"         var="singlevalue"         itemvalue="singlevalue.value"         itemlabel="singlevalue.label" /> </h:selectonemenu>

classcastexception message java.lang.string cannot cast mycustomobjectis thrown. there 1 line in stacktrace maybe can com.sun.faces.cdi.cdiconverter.getasstring(cdiconverter.java:109).

but when converter generics definition changed mycustomobject object :

@facesconverter(value = "myconverter", managed = true)     public class myconverter implements converter<object>{    @override public object getasobject(facescontext context, uicomponent component, string submittedvalue){}  @override public string getasstring(facescontext context, uicomponent component, object modelvalue) {} }

then works expected, beats purpose of converter<t> interface.

i had same issue here , came following solution not compiles works:

some_page.xhtml (relevant excerpt):

<h:selectonemenu styleclass="select" id="companyuserowner" value="#{admincompanydatacontroller.companyuserowner}">     <f:converter converterid="userconverter" />     <f:selectitem itemvalue="#{null}" itemlabel="#{msg.none_selected}" />     <f:selectitems value="#{usercontroller.allusers()}" var="companyuserowner" itemvalue="#{companyuserowner}" itemlabel="#{companyuserowner.usercontact.contactfirstname} #{companyuserowner.usercontact.contactfamilyname} (#{companyuserowner.username})" /> </h:selectonemenu>

please note above jsf code full of custom stuff , may not work on end. , converter compiling without rawtype warning:

someuserconverter.java:

@facesconverter (value = "userconverter") public class someuserconverter implements converter<user> {      /**      * user ejb      */     private static usersessionbeanremote user_bean;      /**      * default constructor      */     public financialsuserconverter () {     }      @override     public user getasobject (final facescontext context, final uicomponent component, final string submittedvalue) {         // value null or empty?         if ((null == submittedvalue) || (submittedvalue.trim().isempty())) {             // warning message             // @todo not working jndi (no remote interface) this.loggerbeanlocal.logwarning(messageformat.format("{0}.getasobject(): submittedvalue null or empty - exit!", this.getclass().getsimplename())); //noi18n              // return null             return null;         }          // init instance         user user = null;          try {             // try parse value long             long userid = long.valueof(submittedvalue);              // try user instance             user = user_bean.finduserbyid(userid);         } catch (final numberformatexception ex) {             // throw again             throw new converterexception(ex);         } catch (final usernotfoundexception ex) {             // debug message             // @todo not working jndi (no remote interface) this.loggerbeanlocal.logdebug(messageformat.format("getasobject: exception: {0} - returning null ...", ex)); //noi18n         }          // return         return user;     }      @override     public string getasstring (final facescontext context, final uicomponent component, final user value) {         // object null?         if ((null == value) || (string.valueof(value).isempty())) {             // null             return ""; //noi18n         }          // return id number         return string.valueof(value.getuserid());     }  }

the converter class has jndi lookup removed (i rewrite part later anyway) should enough demonstrating right parts:

  • converter<user> (by user custom poji) preventing raw-type warning
  • value="userconverter" actual name use in jsf page
  • and important, fixed classcastexception:
  • <f:selectitem itemvalue="#{null}" itemlabel="#{msg.none_selected}" />
  • by omitting #{null} empty string instead of null being handled on getasstring method!

this last 1 fixed said exception , application working again lesser warnings , better type-hinting.

need remove forclass value there: facesconverter using both value , forclass, value applied.


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