eu to tentando fazer paginação com displaytag, mais fica muito gambiarra, não existe um componete para isso ?, eu tentei com hibernate mais não funcionou, gostaria de saber como vocês fazerm !
aqui o código do hibernate:
paginationCode
import org.apache.log4j.Logger;
import java.util.List;
/**
* @author Pietro Polsinelli ppolsinelli@open-lab.com
*/
public interface Page {
boolean isFirstPage();
boolean isLastPage();
boolean hasNextPage();
boolean hasPreviousPage();
int getLastPageNumber();
List getThisPageElements();
Logger getLogger();
int getTotalNumberOfElements();
int getThisPageFirstElementNumber();
int getThisPageLastElementNumber();
int getNextPageNumber();
int getPreviousPageNumber();
int getPageSize();
int getPageNumber();
List getAllElements();
}
package org.jblooming.page;
import org.apache.log4j.Logger;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.ScrollMode;
import org.hibernate.ScrollableResults;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* @author Pietro Polsinelli ppolsinelli@open-lab.com
*/
public class HibernatePage implements Page {
protected Query query;
protected List elements;
protected int pageSize;
protected int pageNumber;
protected int totalElements = -1;
public static Set jdbcClassesSupportingScrollCursors = new HashSet();
private ScrollableResults scrollableResults;
public static final int DEFAULT_PAGE_SIZE = 10 ;
private HibernatePage(int pageNumber, int pageSize) {
this.pageNumber = pageNumber;
this.pageSize = pageSize;
}
public boolean isFirstPage() {
return getPageNumber() == 0;
}
public boolean isLastPage() {
return getPageNumber() >= getLastPageNumber();
}
public boolean hasNextPage() {
return !isLastPage();
}
public boolean hasPreviousPage() {
return getPageNumber() > 0;
}
public int getLastPageNumber() {
double totalResults = new Integer(getTotalNumberOfElements()).doubleValue();
return new Double(Math.floor(totalResults / getPageSize())).intValue();
}
public List getThisPageElements() {
return elements;
}
public Logger getLogger() {
//WARN: THIS CODE MUST BE REPLACED
return Logger.getLogger("platformLogger");
}
public int getTotalNumberOfElements() {
return totalElements;
}
public int getThisPageFirstElementNumber() {
return getPageNumber() * getPageSize() + 1;
}
public int getThisPageLastElementNumber() {
int fullPage = getThisPageFirstElementNumber() + getPageSize() - 1;
return getTotalNumberOfElements() < fullPage ?
getTotalNumberOfElements() :
fullPage;
}
public int getNextPageNumber() {
return getPageNumber() + 1;
}
public int getPreviousPageNumber() {
return getPageNumber() - 1;
}
public int getPageSize() {
return pageSize;
}
public int getPageNumber() {
return pageNumber;
}
public List getAllElements() {
HibernatePage pageTmp = getHibernatePageInstance(query,1,getTotalNumberOfElements());
return pageTmp.getThisPageElements();
}
public static HibernatePage getHibernatePageInstance(Query query, int pageNumber, int pageSize) {
return getHibernatePageInstance(query, pageNumber, pageSize, [put here the driver_class of your Hibernate configuration]);
}
public static HibernatePage getHibernatePageInstance(Query query,
int pageNumber,
int pageSize,
String driverClass) {
if (query.getQueryString().toLowerCase().indexOf("order by")==-1) {
// WARN IN SOME WAY: warn("Using pagination without order by can lead to inconsistent results, for example on certain Oracle instances: "+query.getQueryString());
}
if (jdbcClassesSupportingScrollCursors.contains(driverClass))
return HibernatePage.getScrollPageInstanceWithTotalByScroll(query, pageNumber, pageSize);
else
return HibernatePage.getScrollPageInstanceWithTotalByList(query, pageNumber, pageSize);
}
/**
* Construct a new HibernatePage. HibernatePage numbers are zero-based so the
* first page is page 0.
*
* @param query the Hibernate Query
* @param pageNumber the page number (zero-based);
* if Integer.MAX_VALUE will return the last page for the query
* @param pageSize the number of results to display on the page
*/
protected static HibernatePage getScrollPageInstanceWithTotalByScroll(Query query, int pageNumber, int pageSize) {
HibernatePage sp = new HibernatePage(pageNumber, pageSize);
sp.query = query;
try {
sp.scrollableResults = query.scroll(ScrollMode.SCROLL_SENSITIVE);
sp.scrollableResults.last();
sp.totalElements = sp.scrollableResults.getRowNumber();
sp.fixThisPageElements();
sp.scrollableResults.close();
} catch (HibernateException e) {
sp.getLogger().error("Failed to create ScrollPage by getScrollPageInstanceWithTotalByScroll: " + e.getMessage());
throw new RuntimeException(e);
}
return sp;
}
/**
* Construct a new HibernatePage. HibernatePage numbers are zero-based so the
* first page is page 0.
*
* @param query the Hibernate Query
* @param pageNumber the page number (zero-based);
* if Integer.MAX_VALUE will return the last page for the query
* @param pageSize the number of results to display on the page
*/
protected static HibernatePage getScrollPageInstanceWithTotalByList(Query query, int pageNumber, int pageSize) {
HibernatePage sp = new HibernatePage(pageNumber, pageSize);
sp.query = query;
try {
//bacame useless
//sp.scrollableResults = query.scroll(ScrollMode.FORWARD_ONLY);
sp.totalElements = sp.calculateTotalElementsByList();
sp.fixThisPageElements();
} catch (HibernateException e) {
sp.getLogger().error("Failed to create ScrollPage by getScrollPageInstanceWithTotalByQuery: " + e.getMessage());
throw new RuntimeException(e);
}
return sp;
}
private void fixThisPageElements() throws HibernateException {
if (this.pageSize<=0)
this.pageSize=HibernatePage.DEFAULT_PAGE_SIZE;
if (Integer.MAX_VALUE == this.pageNumber)
this.pageNumber = (getTotalNumberOfElements() / this.pageSize);
else if (pageNumber>(totalElements/pageSize))
pageNumber = totalElements/pageSize;
query = query.setFirstResult(this.pageNumber * this.pageSize);
query = query.setMaxResults(this.pageSize);
elements = query.list();
}
private int calculateTotalElementsByList() throws HibernateException {
return query.list().size()-1;
}
}
package org.jblooming.page;
import org.apache.log4j.Logger;
import java.util.List;
/**
* @author Pietro Polsinelli ppolsinelli@open-lab.com
*/
public class ListPage implements Page {
private List elements;
private int pageSize;
private int pageNumber;
/**
* Construct a new ListPage. ListPage numbers are zero-based, so the
* first page is page 0.
*
* @param pageNumber the page number (zero-based);
* if Integer.MAX_VALUE will return the last page for the query
* @param pageSize the number of results to display on the page
*/
public ListPage(List elements, int pageNumber, int pageSize) {
this.elements = elements;
this.pageSize = pageSize;
this.pageNumber = pageNumber;
if (Integer.MAX_VALUE == this.pageNumber)
this.pageNumber = (getTotalNumberOfElements() / this.pageSize);
else if (this.pageNumber > (getTotalNumberOfElements() / this.pageSize))
this.pageNumber = (elements.size()-1) / this.pageSize;
}
public boolean isFirstPage() {
return getPageNumber() == 0;
}
public boolean isLastPage() {
return getPageNumber() >= getLastPageNumber();
}
public boolean hasNextPage() {
return !isLastPage();
}
public boolean hasPreviousPage() {
return getPageNumber() > 0;
}
public int getLastPageNumber() {
/*
* We use the Math.floor() method because page numbers are zero-based
* (i.e. the first page is page 0).
*/
double totalResults = new Integer(getTotalNumberOfElements()).doubleValue();
return new Double(Math.floor(totalResults / getPageSize())).intValue();
}
public List getThisPageElements() {
/*
* Since we retrieved one more than the specified pageSize when the
* class was constructed, we now trim it down to the pageSize if a next
* page exists.
*/
final int start = getPageNumber() * getPageSize();
return elements.subList(Math.min(start, getTotalNumberOfElements() + 1),
Math.min(start + getPageSize(), getTotalNumberOfElements() + 1));
}
public Logger getLogger() {
//WARN: THIS CODE MUST BE REPLACED
return Logger.getLogger("platformLogger");
}
/**
* this is 0-based, differently from list.size();
*/
public int getTotalNumberOfElements() {
return elements.size() - 1;
}
public int getThisPageFirstElementNumber() {
return getPageNumber() * getPageSize() + 1;
}
public int getThisPageLastElementNumber() {
int fullPage = getThisPageFirstElementNumber() + getPageSize() - 1;
return getTotalNumberOfElements() < fullPage ?
getTotalNumberOfElements() :
fullPage;
}
public int getNextPageNumber() {
return getPageNumber() + 1;
}
public int getPreviousPageNumber() {
return getPageNumber() - 1;
}
public int getPageSize() {
return pageSize;
}
public int getPageNumber() {
return pageNumber;
}
public List getAllElements() {
return elements;
}
}