Spring 3 binding list of object with primitive datatype

Question

I am beginner and using Spring 3.

I have following beans

public class Record {
    private String title;
    private double amount;

    //Getter and Setter
}

public class RecordBean {
    private List<Record> records;

    public RecordBean() {
        this.records = LazyList.lazyList(new ArrayList<Record>(), new InstantiateFactory<Record>(Record.class));
    }

    //Getter and Setter
}

I have added RecordBean to model

modelMap.add('recordBean',new RecordBean());

Following is Spring Form

<form:form action="/save" method="POST" commandName="recordBean">

    <form:input path="records[0].title"/>
    <form:input path="records[0].amount"/>

    <form:input path="records[1].title"/>
    <form:input path="records[1].amount"/>

    <input type="submit" value="Save"/>
</form:form>

I've also added InitBinder to Controller

@InitBinder
public void initBinder(WebDataBinder binder) {
    binder.registerCustomEditor(Double.class, new CustomNumberEditor(Double.class, true));
}

Now, if i enter value for amount[0] and leave blank for amount[1] and submit the form, i am getting typeMismatch error.

Field error in object 'recordBean' on field 'records[1].amount': rejected value []; codes [typeMismatch.recordBean.records[1].amount,typeMismatch.recordBean.records.amount,typeMismatch.records[1].amount,typeMismatch.records.amount,typeMismatch.amount,typeMismatch.double,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [recordBean.records[1].amount,records[1].amount]; arguments []; default message [records[1].amount]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'double' for property 'records[1].amount'; nested exception is java.lang.NumberFormatException: empty String]

Please advise.

Thanks

Answer 1

Maybe try changing from: "double" to "Double" for this line:

private double amount;