Vaadin-ComboBox默认情况下是否惰性加载？

Question

Vaadin 7.6.2

BeanitemContainer

BeanItemContainer<CountryBean> countryBeanContainer 
        = new BeanItemContainer<>(CountryBean.class);
countryBeanContainer.addAll(CountryData.list);                
country.setContainerDataSource(countryBeanContainer);
country.setItemCaptionMode(AbstractSelect.ItemCaptionMode.PROPERTY);
country.setItemCaptionPropertyId("name");
country.setTextInputAllowed(true);
...
...

public class CountryBean {

    private String value;
    private String name;

    public CountryBean(String value, String name) {
        this.value = value;
        this.name = name;
    }

    public String getValue() {
        return this.value;
    }

    public void setValue(String value) {
        this.value = value;
    }

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

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

public abstract class CountryData {        
    public static final List<CountryBean> list = 
            Collections.unmodifiableList(Arrays.asList(
                    new CountryBean("AF", "Afghanistan"),
                    new CountryBean("AX", "Åland Islands"),
                    new CountryBean("AL", "Albania"),
                    new CountryBean("DZ", "Algeria"),
                    new CountryBean("AS", "American Samoa"),
                    new CountryBean("AD", "Andorra"),
                    new CountryBean("AO", "Angola"),
                    new CountryBean("AI", "Anguilla"),
                    ...
                    ...

Answer 1

ComboBox正在处理客户端和服务器之间的惰性加载。只有在下拉列表中可见的行才会从服务器获取到客户端。因此，当您在下拉列表中进行筛选或在不同页面之间导航时，它只会从服务器中获取这些行。