zk两种分页模式之比较

zk两种分页方式之比较
ZK提供两种分页方式，一种是自带的“mold="paging"”的形式；另一种是采用“<paging>”组件添加分页功能。具体实现如下：

第一种：采用自带的“mold="paging"”：

infoList.zul:

<zk>
	<window id="mainwin" border="normal" width="600px"
		apply="${myComposer}">
		<listbox id="li" mold="paging" pageSize="5">
			<listhead>
				<listheader label="Id" sort="auto(Id)"/>
				<listheader label="Name" sort="auto(Name)"/>
				<listheader label="Address" sort="auto(Address)"/>
				<listheader />
			</listhead>
			<listitem self="@{each=in }">
				<listcell id="colId" label="@{in.id }"></listcell>
				<listcell id="colName" label="@{in.name }"></listcell>
				<listcell id="colAddr" label="@{in.address }"></listcell>
				<listcell></listcell>
			</listitem>
		</listbox>
	</window>
</zk>

后台控制类 MyComposer.java:

public class MyComposer extends GenericForwardComposer {

	protected Textbox name;
	protected Textbox address;
	private Listbox li;

	private Window mainwin;

	private AnnotateDataBinder binder;

	private Service service;
	private List<Info> infoList;
	private int totalsize;

	public void setInfoList(List<Info> infoList) {
		this.infoList = infoList;
	}

	public void setService(Service service) {
		this.service = service;
	}

	public void onCreate$mainwin(Event event) throws Exception {
		binder = new AnnotateDataBinder(mainwin);
		binder.loadAll();
	}

	public void doAfterCompose(Component component) throws Exception {
		super.doAfterCompose(component);

		infoList = service.findAllInfos();
		totalsize = infoList.size();

		li.setModel(new ListModelList(infoList));
		li.setItemRenderer(new ListitemRenderer() {
			@Override
			public void render(Listitem item, Object data) throws Exception {
				// TODO Auto-generated method stub
				Info itinfo = (Info) data;

				Listcell colId = new Listcell();
				Listcell colName = new Listcell();
				Listcell colAddr = new Listcell();

				colId.setLabel(itinfo.getId().toString());
				colId.setParent(item);

				colName.setLabel(itinfo.getName());
				colName.setParent(item);

				colAddr.setLabel(itinfo.getAddress());
				colAddr.setParent(item);
			}
		});
	}
}

第二种：采用“<paging>”组件进行分页：

paging.zul:

<zk>
	<window id="pagingWin" title="paging" border="normal"
		apply="${paging_ctrl}">
		<grid>
			<rows>
				<row>人员列表:</row>
				<row>
					<listbox id="li" width="100%">
						<listhead>
							<listheader label="ID" sort="auto(Id)" />
							<listheader label="姓名" />
							<listheader label="地址" />
						</listhead>
					</listbox>
					<separator />
				</row>
			</rows>
		</grid>
		<paging id="pge" pageSize="10"></paging>
	</window>
</zk>

后台控制类Paging_ctrl.java：

public class Paging_ctrl extends GenericForwardComposer {
	private AnnotateDataBinder binder;
	
	private Window pagingWin;
	private Listbox li;
	private Paging pge;

	private List<Info> infoList;
	int maxCount = 0;
	private Service service;
	
	public void onCreate$pagingWin(Event event) throws Exception {
		binder = new AnnotateDataBinder(pagingWin);
		binder.loadAll();
	}
	
	public void doAfterCompose(Component component) throws Exception {
		super.doAfterCompose(component);
		
		maxCount = service.findAllInfos().size();
		pge.setTotalSize(maxCount);
		final int PAGE_SIZE = pge.getPageSize();
		
		redraw(0, PAGE_SIZE);
		
		pge.addEventListener("onPaging", new EventListener() {
			public void onEvent(Event event) {
				PagingEvent pe = (PagingEvent) event;
				int pgno = pe.getActivePage();// 页数(从零计算)
				int start = pgno * PAGE_SIZE;
				
				redraw(start, PAGE_SIZE);
			}
		});
	}
	
    @SuppressWarnings("unchecked")
    private void redraw(int offSet, int pageSize) {
        li.getItems().clear();
        
        List<Info> list = service.findInfoByPage(offSet, pageSize);
        
        for (Info info : list) {
            Listitem item = new Listitem();
            item.setValue(info);
            item.appendChild(new Listcell("" + info.getId()));
            item.appendChild(new Listcell(info.getName()));
            item.appendChild(new Listcell(info.getAddress()));
            li.appendChild(item);
        }
    }
    
	public void setService(Service service) {
		this.service = service;
	}
	
}

分析：
第一种方式是把数据全部加载到内存再进行分页，达到几十W跳数据后将降低性能；
而第二种方式则采用hibernate的分页查询方式，性能将大大加强。因此推荐第二种方式。