design-patterns - JSF MVC 设计问题

Question

我有一个 JSF 支持 bean 设计问题。现在，我的支持 bean 正在保存 UI 显示信息和业务模式数据。人们建议模型和 View 应该分开。那么创建不同的 bean 保存 UI 显示数据并让支持 bean 引用它是个好主意吗？

Answer 1

so is it good idea to create different bean the holding UI display data and have backing have reference to it?

是的，否则您将继续从模型映射数据以查看自己，同时您也可以让 JSF/EL 这样​​做。顺便说一下，它不一定需要是 JSF @ManagedBean .

例如。这很糟糕:

@ManagedBean
@RequestScoped
public class ProductEditor {

    private String productName;
    private String productDescription;
    private BigDecimal productPrice;

    public String add() {
        Product product = new Product();
        product.setName(productName);
        product.setDescription(productDescription);
        product.setPrice(productPrice);
        productService.save(product);
        return "view";
    }

    // In total 6 getters and setters.
}

和

<h:form>
    <h:inputText value="#{productEditor.productName}" />
    <h:inputTextarea value="#{productEditor.productDescription}" />
    <h:inputText value="#{productEditor.productPrice}">
        <f:convertNumber type="currency" currencySymbol="$" />
    </h:inputText>
    <h:commandButton value="Add" action="#{productEditor.add}" />
</h:form>

这个更好

@ManagedBean
@RequestScoped
public class ProductEditor {

    private Product product;

    @PostConstruct
    public void init() {
        product = new Product(); // You could also preload from DB based on some ID as request parameter.
    }

    public String add() {
        productService.save(product);
        return "view";
    }

    // Only 1 getter.
}

和

<h:form>
    <h:inputText value="#{productEditor.product.name}" />
    <h:inputTextarea value="#{productEditor.product.description}" />
    <h:inputText value="#{productEditor.product.price}">
        <f:convertNumber type="currency" currencySymbol="$" />
    </h:inputText>
    <h:commandButton value="Add" action="#{productEditor.add}" />
</h:form>

另请参阅 this JSF 2.0 tutorial 提供的示例.