com.proper.uip.common.utils.Page.java Source code

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Here is the source code for com.proper.uip.common.utils.Page.java

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/**
 * Copyright (c) 2005-2011 springside.org.cn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * 
 * $Id: Page.java 1453 2011-01-02 14:21:45Z calvinxiu $
 */
package com.proper.uip.common.utils;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.collections.IteratorUtils;
import org.apache.commons.lang.StringUtils;

/**
 * ORM???.
 * ???, ?Paginator.
 * 
 * @param <T> Page.
 * 
 */
public class Page<T> implements Serializable, Iterable<T> {
    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    //-- ? --//
    protected int pageNo = 1;
    protected int pageSize = 10;
    protected String orderBy = null;
    protected String order = null;

    //--  --//
    protected List<T> rows = new ArrayList<T>();
    protected long total = 0;

    protected List<T> footer = new ArrayList<T>();

    public List<T> getFooter() {
        return footer;
    }

    public void setFooter(List<T> footer) {
        this.footer = footer;
    }

    //--  --//
    public Page() {
    }

    public Page(PageConfig config) {
        this.pageNo = config.pageNo;
        this.pageSize = config.pageSize;
        this.order = config.order;
        this.orderBy = config.orderBy;
    }

    //-- ? --//
    /**
     * ??,??1,1.
     */
    public Integer getPageNo() {
        return pageNo;
    }

    /**
     * ??, 0.
     */
    public int getPageSize() {
        return pageSize;
    }

    /**
     * ?,. ?','.
     */
    public String getOrderBy() {
        return orderBy;
    }

    /**
     * ??, .
     */
    public String getOrder() {
        return order;
    }

    /**
     * ???.
     * 
     * @param order ?descasc,?','.
     */
    public void setOrder(final String order) {
        String lowcaseOrder = StringUtils.lowerCase(order);

        //order?
        String[] orders = StringUtils.split(lowcaseOrder, ',');
        for (String orderStr : orders) {
            if (!StringUtils.equals(PageConfig.DESC, orderStr) && !StringUtils.equals(PageConfig.ASC, orderStr)) {
                throw new IllegalArgumentException("??" + orderStr + "??");
            }
        }

        this.order = lowcaseOrder;
    }

    /**
     * ??,.
     */
    public boolean isOrderBySetted() {
        return (StringUtils.isNotBlank(orderBy) && StringUtils.isNotBlank(order));
    }

    /**
     * ?pageNopageSize???,??0.
     * Mysql,Hibernate.
     */
    public int getOffset() {
        return ((pageNo - 1) * pageSize);
    }

    /**
     * ?pageNopageSize???,??1.
     * Oracle.
     */
    public int getStartRow() {
        return getOffset() + 1;
    }

    /**
     * ?pageNopageSize????, ??1.
     * Oracle.
     */
    public int getEndRow() {
        return pageSize * pageNo;
    }

    //--  --//

    /**
     * .
     */
    public List<T> getRows() {
        return rows;
    }

    /**
     * .
     */
    public void setRows(final List<T> rows) {
        this.rows = rows;
    }

    /** 
     * Iterable?,?for(Object item : page)??
     */
    @SuppressWarnings("unchecked")
    public Iterator<T> iterator() {
        return rows == null ? IteratorUtils.EMPTY_ITERATOR : rows.iterator();
    }

    /**
     * , -1.
     */
    public long getTotal() {
        return total;
    }

    /**
     * .
     */
    public void setTotal(final long total) {
        this.total = total;

        // ??, ?
        /*int pageSize = getPageSize();
        if (pageSize > total) {
           this.pageSize = ((int) total);
        }*/

        // , ?
        int pageNo = getPageNo();
        long totalPage = getTotalPages();
        if (pageNo > totalPage) {
            this.pageNo = ((int) totalPage);
        }

    }

    /**
     * ??.
     */
    public boolean isLastPage() {
        return pageNo == getTotalPages();
    }

    /**
     * ?.
     */
    public boolean isHasNextPage() {
        return (pageNo + 1 <= getTotalPages());
    }

    /**
     * ??, ??1.
     * ????.
     */
    public int getNextPage() {
        if (isHasNextPage()) {
            return pageNo + 1;
        } else {
            return pageNo;
        }
    }

    /**
     * ?.
     */
    public boolean isFirstPage() {
        return pageNo == 1;
    }

    /**
     * ?.
     */
    public boolean isHasPrePage() {
        return (pageNo - 1 >= 1);
    }

    /**
     * ??, ??1.
     * ???.
     */
    public int getPrePage() {
        if (isHasPrePage()) {
            return pageNo - 1;
        } else {
            return pageNo;
        }
    }

    /**
     * ?pageSizetotalItems, -1.
     */
    public long getTotalPages() {
        if (total == 0) {
            return 0;
        }

        long count = total / pageSize;
        if (total % pageSize > 0) {
            count++;
        }
        return count;
    }

    /**
     * ??,",23,24,25,26,27,"
     * @param count ??
     * @return pageNo 
     */
    public List<Long> getSlider(int count) {
        int halfSize = count / 2;
        long totalPage = getTotalPages();

        long startPageNumber = Math.max(pageNo - halfSize, 1);
        long endPageNumber = Math.min(startPageNumber + count - 1, totalPage);

        if (endPageNumber - startPageNumber < count) {
            startPageNumber = Math.max(endPageNumber - count, 1);
        }

        List<Long> result = new ArrayList<Long>();
        for (long i = startPageNumber; i <= endPageNumber; i++) {
            result.add(new Long(i));
        }
        return result;
    }

}