clistpaginationtag.java

java 写的一个新闻发布系统

package org.jahia.taglibs.pagination;

import org.jahia.data.JahiaData;
import org.jahia.data.containers.JahiaContainerList;
import org.jahia.data.containers.JahiaContainerListPagination;
import org.jahia.exceptions.JahiaException;
import org.jahia.services.usermanager.JahiaUser;
import org.jahia.taglibs.container.ContainerListTag;
import org.jahia.taglibs.util.Utils;
import org.jahia.utils.JahiaConsole;

import java.io.*;
import java.util.*;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;

/**
 * Lookup for the ContainerListPagination instance of the enclosing ContainerListTag and iterate through the list of paginated pages.
 *
 * <pre>
 *		<<next    -->1 2 3<--     next>>
 * </pre>
 *
 * @author NK
 * @version 1.0
 */

public class CListPaginationTag extends BodyTagSupport {

    private JahiaContainerListPagination cPagination = null;
	private int pageNumber = 0;
	private boolean isCurrentPage = false;
	private Iterator iterator;	
	
	private int nbStepPerPage = -1; // by default, display all page step.
	private String skipOnePageOnly = "true"; // by default skip displaying pagination if there is only one page
	
	private int startPageIndex = 0;
	private int stopPageIndex = 0;

	/**
	 * Return the number of step per displayed page.
	 */
	public int getNbStepPerPage(){
		return this.nbStepPerPage;
	}

	/**
	 * Set the number of step per displayed page.
	 */
	public void setNbStepPerPage( int nbStepPerPage ){
		this.nbStepPerPage = nbStepPerPage;
	}

	/**
	 * Return the value of the status skipOnePageOnly.
	 */
	public String skipOnePageOnly(){
		return this.skipOnePageOnly;
	}

	/**
	 * Set the value of the status skipOnePageOnly ( true/false ).
	 */
	public void setSkipOnePageOnly(String val){
		if ( val != null ){
			this.skipOnePageOnly = val.toLowerCase();
		}
	}

	/**
	 * The next iterated page number from the list of paginated pages.
	 */
	public int getPageNumber(){
		return this.pageNumber;
	}
	
	/**
	 * Return true if the pageIndex is equals to the current displayed page.
	 */
	public boolean isCurrentPage(){
		return isCurrentPage;
	}

	/**
	 * Return the stop page index.
	 */
	public int getStopPageIndex(){
		return this.stopPageIndex;
	}

	/**
	 * Return the start page index.
	 */
	public int getStartPageIndex(){
		return this.startPageIndex;
	}
		
    public int doStartTag() {
        //JahiaConsole.println("CListPaginationTag.doStartTag", "Started");

        // gets the enclosing tag ContainerListTag
        ContainerListTag containerListTag = (ContainerListTag) findAncestorWithClass(this, ContainerListTag.class);
        if (containerListTag != null && !containerListTag.isDeclarationPass()) {
        	JahiaContainerList cList = containerListTag.getContainerList();
        	if ( cList != null )
        	{
        		cPagination = cList.getCtnListPagination();
        		if ( cPagination != null && cPagination.isValid() )
        		{
	     			if ( cPagination.getNbPages()==1 && this.skipOnePageOnly.equals("true") ){
						return SKIP_BODY;
					}
        			if ( this.nbStepPerPage<=0 ){
        				this.startPageIndex = 1;
        				this.stopPageIndex = cPagination.getNbPages();
        				this.pageNumber =1;
        			} else {
        				if ( cPagination.getCurrentPageIndex()<=this.nbStepPerPage ){
        					this.startPageIndex = 1;
        					this.stopPageIndex = this.nbStepPerPage;
        				} else {
        			        if ( (cPagination.getCurrentPageIndex()%this.nbStepPerPage)==0 ){
        					    this.startPageIndex = ( cPagination.getCurrentPageIndex() - this.nbStepPerPage ) + 1;
        					} else {    
        					    this.startPageIndex = cPagination.getCurrentPageIndex() - ( cPagination.getCurrentPageIndex() % this.nbStepPerPage ) + 1;
                            }
        				    this.stopPageIndex = this.startPageIndex + this.nbStepPerPage-1;
        				}
        			}
        			iterator = cPagination.getPages().iterator();
        			while (iterator.hasNext() && (this.pageNumber<this.startPageIndex-1) ){
        				iterator.next();
        				this.pageNumber +=1;
        			}
     				if ( iterator.hasNext() ){
     				    Integer I = (Integer)iterator.next();
     				    this.pageNumber = I.intValue();
     				    this.isCurrentPage = ( this.pageNumber == cPagination.getCurrentPageIndex() );
     				    return EVAL_BODY_BUFFERED;
     				} else {
     				    return SKIP_BODY;
     				}
    			}	   			
            }
        }
        return SKIP_BODY;
    }


	public int doAfterBody() throws JspTagException {
	   	BodyContent body = getBodyContent();
	   	try {
	      	body.writeOut(getPreviousOut());
	   	} catch (IOException e) {
	      	throw new JspTagException("CListPaginationTag.doAfterBody : " +
	        	e.getMessage());
	   	}
	
	   	// clear up so the next time the body content is empty
	   	body.clearBody();
	   	if (iterator.hasNext() && (this.pageNumber<this.stopPageIndex) ) 
	   	{
			Integer I = (Integer)iterator.next();
			this.pageNumber = I.intValue();
			this.isCurrentPage = ( this.pageNumber == cPagination.getCurrentPageIndex() );
			return EVAL_BODY_BUFFERED;
	   }
	   return SKIP_BODY;
	}



}