如何将selectManyListbox中选择的数据存储到JSF中的List中？

Question

我在JSF中有一个selectmanyListbox组件,现在我想将所选数据存储到List中.这该怎么做？

Answer 1

与每个UIInput组件一样,您只需将value属性与辅助bean 的属性绑定即可.因此,所以:

<h:form>
    <h:selectManyListbox value="#{bean.selectedItems}">
        <f:selectItems value="#{bean.selectItems}" />
    </h:selectManyListbox>
    <h:commandButton value="submit" action="#{bean.submit}" />
</h:form>

在Bean课堂上有以下内容:

private List<String> selectedItems; // + getter + setter
private List<SelectItem> selectItems; // + getter only

public Bean() {
    // Fill select items during Bean initialization/construction.
    selectItems = new ArrayList<SelectItem>();
    selectItems.add(new SelectItem("value1", "label1"));
    selectItems.add(new SelectItem("value2", "label2"));
    selectItems.add(new SelectItem("value3", "label3"));
}

public void submit() {
    // JSF has already put selected items in `selectedItems`.
    for (String selectedItem : selectedItems) {
        System.out.println("Selected item: " + selectedItem); // Prints value1, value2 and/or value3, depending on selection.
    }
}

如果你想使用非标准对象作为SelectItem值(即不是a String,Number或者BooleanEL已经内置强制),那么你必须为此创建一个Converter.更多细节可以在这篇博客文章中找到.