我只是在展示代码中为“
DataTable – Lazy Loading”启用了多个排序
datatableLazy.xhtml
<html lang="en" xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:p="http://primefaces.org/ui"
xmlns:ui="http://java.sun.com/jsf/facelets">
<h:head>
<title>CarDataTable</title>
</h:head>
<h:body>
<h:form id="form">
<p:dataTable var="car" value="#{tableBean.lazyModel}" paginator="true"
rows="10"
paginatorTemplate="{RowsPerPageDropdown} {FirstPageLink} {PrevIoUsPageLink} {CurrentPageReport} {NextPageLink} {LastPageLink}"
rowsPerPageTemplate="5,10,15" id="carTable" lazy="true"
sortMode="multiple">
<p:ajax event="rowSelect" listener="#{tableBean.onRowSelect}"
update=":form:display" oncomplete="carDialog.show()" />
<p:column headerText="Model" sortBy="#{car.model}"
filterBy="#{car.model}">
<h:outputText value="#{car.model}" />
</p:column>
<p:column headerText="Year" sortBy="#{car.year}"
filterBy="#{car.year}">
<h:outputText value="#{car.year}" />
</p:column>
<p:column headerText="Manufacturer" sortBy="#{car.manufacturer}"
filterBy="#{car.manufacturer}">
<h:outputText value="#{car.manufacturer}" />
</p:column>
<p:column headerText="Color" sortBy="#{car.color}"
filterBy="#{car.color}">
<h:outputText value="#{car.color}" />
</p:column>
</p:dataTable>
</h:form>
</h:body>
</html>
TableBean.java
package com.solartis.primefaces.sample;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import javax.faces.bean.ManagedBean;
import org.primefaces.model.LazyDataModel;
@ManagedBean
public class TableBean {
private LazyDataModel<Car> lazyModel;
private Car selectedCar;
private List<Car> cars = new ArrayList<Car>();
private final static String[] colors;
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";
}
public TableBean() {
populaterandomCars(cars,50);
lazyModel = new LazyCarDataModel(cars);
}
public Car getSelectedCar() {
return selectedCar;
}
public void setSelectedCar(Car selectedCar) {
this.selectedCar = selectedCar;
}
public LazyDataModel<Car> getLazyModel() {
return lazyModel;
}
private void populaterandomCars(List<Car> list,int size) {
for (int i = 0; i < size; i++) {
list.add(new Car(getRandomModel(),getRandomYear(),getRandomManufacturer(),getRandomColor()));
}
}
private String getRandomColor() {
return colors[(int) (Math.random() * 10)];
}
private String getRandomManufacturer() {
return manufacturers[(int) (Math.random() * 10)];
}
private int getRandomYear() {
return (int) (Math.random() * 50 + 1960);
}
private String getRandomModel() {
return UUID.randomUUID().toString().substring(0,8);
}
}
LazyCarDataModel.java
package com.solartis.primefaces.sample;
import java.util.ArrayList;
/**
* Dummy implementation of LazyDataModel that uses a list to mimic a real
datasource like a database.
*/
public class LazyCarDataModel extends LazyDataModel<Car> {
private List<Car> datasource;
public LazyCarDataModel(List<Car> datasource) {
this.datasource = datasource;
}
@Override
public Car getRowData(String rowKey) {
for(Car car : datasource) {
if(car.getModel().equals(rowKey))
return car;
}
return null;
}
@Override
public void setRowIndex(int rowIndex) {
if (rowIndex == -1 || getPageSize() == 0) {
super.setRowIndex(-1);
} else
super.setRowIndex(rowIndex % getPageSize());
}
@Override
public Object getRowKey(Car car) {
return car.getModel();
}
@Override
public List<Car> load(int first,int pageSize,List<SortMeta> multiSortMeta,Map<String,String> filters) {
System.out.println("\nTHE INPUT ParaMETER VALUE OF LOAD METHOD :
\t"+"first=" + first + ",pagesize=" + pageSize + ",multiSortMeta=" +
multiSortMeta + " filter:" + filters);
System.out.println("\nTHE MULTISORTMeta CONTENT : \t");
if (multiSortMeta != null) {
for (SortMeta sortMeta : multiSortMeta) {
System.out.println("SORTFIELD:" +sortMeta.getSortField());
System.out.println("SORTORDER:" +sortMeta.getSortOrder());
System.out.println("SORTFUNCTION:"
+sortMeta.getSortFunction());
System.out.println("COLUMN:" +sortMeta.getColumn());
System.out.println("CLASS:" +sortMeta.getClass());
}
}
List<Car> data = new ArrayList<Car>();
//filter
for(Car car : datasource) {
boolean match = true;
for(Iterator<String> it = filters.keySet().iterator(); it.hasNext();) {
try {
String filterProperty = it.next();
String filterValue = filters.get(filterProperty);
String fieldValue = String.valueOf(car.getClass().
getField(filterProperty).get(car));
if(filterValue == null || fieldValue.startsWith(filterValue)) {
match = true;
}
else {
match = false;
break;
}
} catch(Exception e) {
match = false;
}
}
if(match) {
data.add(car);
}
}
//rowCount
int dataSize = data.size();
this.setRowCount(dataSize);
//paginate
if(dataSize > pageSize) {
try {
return data.subList(first,first + pageSize);
}
catch(indexoutofboundsexception e) {
return data.subList(first,first + (dataSize % pageSize));
}
}
else {
return data;
}
}
}
它很好用,除非我用多列排序分页,带有List< SortMeta>的load()方法.没有给我当前排序到其他页面的列详细信息,不像使用String sortField的load()方法,SortOrder sortOrder给出了那些排序细节.
例如：
>点击“制造商”中的排序箭头,然后按住Ctrl键点击“年份”的排序箭头
>你会得到load()方法的排序列详细信息(我在load方法中打印了输入参数值).
>现在,做分页.这里load()方法无法给出排序列的详细信息
>不仅是分页,如果在单击排序列后输入列过滤器值,则存在同样的问题
我怎样才能解决这个问题？
解决方法
我暂时解决了这个问题……
有一个sessioncoped托管bean用于存储排序列的详细信息,以便在分页期间进入load(),
喜欢：-
有一个sessioncoped托管bean用于存储排序列的详细信息,以便在分页期间进入load(),
喜欢：-
@ManagedBean
@SessionScoped
public class StoreSortColumnDetail implements Serializable{
/** holds multisort values**/
private List<SortMeta> mMultiSortMeta;
public List<SortMeta> getMultiSortMeta() {
return mMultiSortMeta;
}
public void setMultiSortMeta(List<SortMeta> multiSortMeta) {
mMultiSortMeta = multiSortMeta;
}
public void clearMultiSortMeta() {
if(this.mMultiSortMeta != null)
this.mMultiSortMeta.clear();
}
}
并在load()中使用它,如下所示：
@Override
public List<Car> load(int first,String> filters) {
/** Instance to the SessionScoped scoped StoreSortColumnDetail managed bean*/
@ManagedProperty(value="#{StoreSortColumnDetail }")
private StoreSortColumnDetail storeSortColumnDetail ;
public void setStoreSortColumnDetail (StoreSortColumnDetail sortColumnDetail ) {
this.storeSortColumnDetail = sortColumnDetail ;
}
/** to hold the handled sort column detail**/
List<SortMeta> handledMultiSortMeta = new ArrayList<SortMeta>();
/*Here starts the multisortMeta handling process*/
/** check for List<SortMeta> for null**/
if(multiSortMeta != null ) {
/** updates StoreSortColumnDetail's List<SortMeta> with Load()'s List<SortMeta>**/
storeSortColumnDetail.setMultiSortMeta(multiSortMeta);
handledMultiSortMeta = multiSortMeta;
}
/** check for List<SortMeta> for notnull **/
else if (multiSortMeta == null) {
/**assigns Load()'s List<SortMeta> with StoreSortColumnDetail's List<SortMeta>**/
handledMultiSortMeta = storeSortColumnDetail.getMultiSortMeta();
}
/*Now u have handled multisortMeta from load()...
and u can process Now from handledMultiSortMeta*/
}
我希望你知道我是如何处理的,如果不是亲密的我……但这是一种暂时的方式,需要通过primefaces方式处理它…