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JSF java.lang.IllegalArgumentException: Cannot convert 5 of type class java.lang.Integer to class

Answer 1

A:

I have no idea how your JSF code look like, but I suspect that you're using

<h:selectOneMenu value="#{bean.group}">

instead of

<h:selectOneMenu value="#{bean.groupId}">

Your SelectItem[] contains Integer groupId as item values. The value attribute of the h:selectOneMenu must then match this type. The exception message is telling exactly that. The value is submitted as an Integer, but the bean is expecting a Group.

BalusC 2010-09-20 14:44:07

Hi BalusC user.Groups it mean groups Object and GroupID it means Groups ID with integer Type, in JSF file i was get error with <h:selectOneMenu value = #{bean.user.groups} /> when i change selectOneMenu value to bean.groupID or bean.user.groupID it throws Nullpointer Exception

Kency 2010-09-20 16:11:34

Read the stacktrace and fix the code accordingly.

BalusC 2010-09-20 16:26:44

i create new instance of groups in controller private Groups groups ; and in constructor public userController(){ groups = new Groups() } and set set/get methods for groups variable . and JSF in h:selectOneMenu i change value to #{bean.groups} it work well but when i submit form , the same error occur! what's happen with it? Stacktrace the same error i was post above

Kency 2010-09-20 17:01:52

The exception is telling that you're submitting `Integer`, but the bean property expects `Group`. You need to either submit `Group` instead or to change the property to take `Integer`. As I stated in my answer.

BalusC 2010-09-20 17:06:45

An alternative is to create a converter which converts between `Integer` and `Group`, but then you'll have to make changes in how you populate `f:selectItems`. A JSF 2.0 example can be found in [this answer](http://stackoverflow.com/questions/3711572/jsf-select-items-from-subclass/3711621#3711621).

BalusC 2010-09-20 17:20:53

Hi BalusC i following your supported link but new error occur when i Cast Groups for value.getGroupID (integer type) in a getAsString Method ---- return String.valueOf(((Groups)value).getGroupid()); <== this line occour ClassCastException . in JSF page i was indicate name of class Converter is GroupIDConverter and mapped in to face-config.xml file. Once again how to be solved this problem? Thank you before!

Kency 2010-09-21 06:08:49

this not cast Groups for integer ?? what's happen?

Kency 2010-09-21 11:04:57

Then value is not a `Groups` at all. You need to change `SelectItem` values to be `Groups` as well. Your major problem is just that the submitted type and the expected type are both **different**. In your original problem, you're attempting to submit an `Integer` value into a `Groups` bean property. You need to align out the value types. This be done in 2 ways: submit `Integer` value into an `Integer` bean property (e.g. `#{bean.groupsId}` as in answer). OR submit a `Groups` value into an `Groups` bean property (and use a converter because `Groups` is a custom type and not understood by EL).

BalusC 2010-09-21 11:27:27

i was change it into Groups type and used converter class and i was created one method call with name findGroupID with below - public Groups findByGroupId(Integer groups){ try { return em.find(Groups.class, groups); } finally { em.close(); } } and in getObjet Method in Converter class i throw ConverterException with message Cannot convert %s to Groups", value. when i enter info into form and submit, it throw ConverterException , i don't know why it throw Exception??

Kency 2010-09-21 13:03:48

Sorry Kency, I give up. You seem not to understand the importance of typing. I'll give only one more hint: based on the code as you've posted in the question, the above answer still applies. You need to replace `<h:selectOneMenu value="#{bean.groups}">` by `<h:selectOneMenu value="#{bean.groupsId}">` (which takes an `Integer`). That's all.

BalusC 2010-09-21 13:16:20

BalusC i know your comment but when i change bean.groupsID it throws Target null exception, now i try to fix it, anyway thank you for support , :D

Kency 2010-09-21 14:44:23

You need to ensure that the target is not null. This is answered in [your previous question](http://stackoverflow.com/questions/3742523/propertynotfoundexception-target-unreachable-null-returned-null).

BalusC 2010-09-21 14:55:23

Yes! it mean when i show property in form h:selectOnemenu value is a Integer type bean.user.getGroupID , then i change to bean.user.groups <== it not null but type are Groups , now i create method example public Integer getGroupdIDForBean(){this.groups.getGroupID} it return null, now i try solve it, thank you supported me !

Kency 2010-09-21 15:03:06

Now i know my error but i can't solve it :( try again to solve this problem :D

Kency 2010-09-21 19:14:42

What's the exact exception message now?

BalusC 2010-09-21 19:19:00

i create 1 variable with Integer types , it insert ok but get error with transaction, and i know how it error, but i no have any idea for solved it, because Integer variable is not mapped to groups field in table user, should i change mapped type Groups to variable Integer type? it mean groupsid field in user table not reference to groups table. i need one suggest from you! Please help me BalusC

Kency 2010-09-22 07:00:17

now i solved my problem by used Converter class :D , with override getAsObject method follow : public Object getAsObject(FacesContext context, UIComponent component, String value) { if(groups == null){ groups = new Groups(Integer.valueOf(value)); } return groups; }

Kency 2010-09-22 07:53:55

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JSF java.lang.IllegalArgumentException: Cannot convert 5 of type class java.lang.Integer to class

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