f中的EL表达式：dataTable列中的convertNumber不起作用

Question

我正在尝试显示格式化的数字，其中该数字的分数位于与数字本身不同的字段中。一个简单的例子是：1234是普通数字，2是fractionDigit，它合并为12.34

像这样使用<f:convertNumber/>： <f:convertNumber minFractionDigits="#{car.priceDecimals}" maxFractionDigits="#{car.priceDecimals}"/>无处不在，但在数据表列中。如果使用primefaces数据表或基本JSF数据表，则无关紧要。这是Facelet：

<h:form id="form" prependId="true">
    <h1>Primefaces Datatable</h1>
    <p:dataTable id="cars1" var="car" value="#{carBean.carsSmall}" >
        <p:column headerText="Manufacturer">
            <h:outputText value="#{car.manufacturer}" />
        </p:column>
        <p:column headerText="Price Normal">
            <h:outputText value="#{car.price}" />
        </p:column>
        <p:column headerText="Decimals">
            <h:outputText value="#{car.priceDecimals}" />
        </p:column>
        <p:column headerText="Price converted priceDecimals">
            <h:outputText value="#{car.price}">
                <f:convertNumber minFractionDigits="#{car.priceDecimals}" maxFractionDigits="#{car.priceDecimals}"/>                
            </h:outputText>
        </p:column>             
        <p:column headerText="Price converted hardcoded">
            <h:outputText value="#{car.price}">
                <f:convertNumber minFractionDigits="2" maxFractionDigits="2"/>
            </h:outputText>
        </p:column>                                     
    </p:dataTable>

</h:form>

这里是模型类（省略了getter和setter）：

public class Car implements Serializable {

/** The model. */
private String model;

/** The year. */
private int year;

/** The manufacturer. */
private String manufacturer;

/** The color. */
private String color;

/** The price. */
private BigDecimal price;

/** Number of decimals. */
private Integer priceDecimals;

public Car(final String model, final int year, final String manufacturer, final String color,
        final BigDecimal price, final int priceDecimals) {
    this.model = model;
    this.year = year;
    this.manufacturer = manufacturer;
    this.color = color;
    this.price = price;
    this.priceDecimals = priceDecimals; }
}

这是我的豆子

@Named
@ViewScoped
public class CarBean implements Serializable {

/** The Constant serialVersionUID. */
private static final long serialVersionUID = 1L;

/** The Constant colors. */
private final static String[] colors;

/** The Constant manufacturers. */
private final static String[] manufacturers;


static {
    colors = new String[10];
    colors[0] = "Black";
    colors[1] = "White";
    colors[2] = "Green";
    colors[3] = "Red";
    colors[4] = "Blue";
    colors[5] = "Orange";
    colors[6] = "Silver";
    colors[7] = "Yellow";
    colors[8] = "Brown";
    colors[9] = "Maroon";

    manufacturers = new String[10];
    manufacturers[0] = "Mercedes";
    manufacturers[1] = "BMW";
    manufacturers[2] = "Volvo";
    manufacturers[3] = "Audi";
    manufacturers[4] = "Renault";
    manufacturers[5] = "Opel";
    manufacturers[6] = "Volkswagen";
    manufacturers[7] = "Chrysler";
    manufacturers[8] = "Ferrari";
    manufacturers[9] = "Ford";
}

/** The cars small. */
private List<Car> carsSmall;



public CarBean() {
    this.carsSmall = new ArrayList<Car>();

    this.populateRandomCars(this.carsSmall, 9);

}

private void populateRandomCars(final List<Car> list, final int size) {
    for (int i = 0; i < size; i++) {
        list.add(new Car(this.getRandomModel(), this.getRandomYear(), this.getRandomManufacturer(), this
                .getRandomColor(), this.getRandomPrice(), this.getRandomDecimals()));
    }
}


public List<Car> getCarsSmall() {
    return this.carsSmall;
}


private int getRandomYear() {
    return (int) (Math.random() * 50 + 1960);
}


private String getRandomColor() {
    return colors[(int) (Math.random() * 10)];
}


private String getRandomManufacturer() {
    return manufacturers[(int) (Math.random() * 10)];
}


private String getRandomModel() {
    return UUID.randomUUID().toString().substring(0, 8);
}


private BigDecimal getRandomPrice() {
    return new BigDecimal("12.34");
}


private Integer getRandomDecimals() {
    return new Integer(2);
}


public String[] getManufacturers() {
    return manufacturers;
}


public String[] getColors() {
    return colors;
}
  }

因此它以“硬编码”方式工作，但EL表达式按指定评估为java.lang.Integer。我在MyFaces 2.0.5（Websphere）和JBoss7上使用Mojarra 2.1.3进行了测试

EL表达式适用于c：forEach，但由于一些奇怪的原因，它在数据表中不起作用。

有什么想法吗？