Call setter-method for array when binding model data [SPR-17472]

[spring-projects-issues]

Patrik Starck opened SPR-17472 and commented

Problem

This is an issue concerning when you bind data for a model, for example when submitting a form with a modelAttribute bound to it. If the item to be set is of a multidimensional type, the setter of the property will never be called. 

Consider the following code:

 

public class Product {

    private String name;
    private String imageStr;
    private List<ProdutImage> productImageList;

    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<ProductImage> getProductImageList() {
        return this.productImageList;
    }

    public void setProductImageList(List<ProductImage> productImageList) {
        this.productImageList = productImageList;
        if (productImageList != null) {
            this.imageStr = [...]// convert list to json string
        }
    }

}

And the corresponding JSP-page:

<form>
      <form:input type="text" path="product.name"/>
      <form:input type="text" path="product.productImageList[0]"/>
      <form:input type="text" path="product.productImageList[1]"/>
      <form:input type="text" path="product.productImageList[2]"/>
</form>

When submitting the form, the "setName" is be called, but not the "setProductImageList".

I don't think this is intened?

Proposed Solution

The problem occurs in the class AbstractNestablePropertyAccessor in function processKeyedProperty. When using an array/list/vector or other multi-dimensional container, the function doesn't call the write method for the current PropertyHandler.

A fix would be to add this line of code

ph.setValue(list);

after this line

list.add(convertedValue);

Then one would apply the same approach for "Map" and "Array" as well which is defined in the same function.

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Affects: 5.1.2

[spring-projects-issues]

Juergen Hoeller commented

This works as designed: Each such entry will be bound individually, dereferencing the list through its getter method and setting/adding the value at the corresponding index. A setter method for the entire list will only be called if a single value (e.g. comma-separated) is bound to the property itself, i.e. without any index, decomposing the value into a complete list of entries.