Java tutorial
/** * Copyright (c) 2005-2009 springside.org.cn * * Licensed under the Apache License, Version 2.0 (the "License"); * * $Id: Page.java,v 1.2 2012/07/23 01:46:22 zhangyx Exp $ */ package com.cndatacom.core.orm; import java.util.List; import org.apache.commons.lang.StringUtils; import com.google.common.collect.Lists; /** * ORM???. * ???1. * * @param <T> Page. * * @author calvin */ public class Page<T> { //-- ?? --// public static final String ASC = "asc"; public static final String DESC = "desc"; //-- ? --// protected int pageNo = 1; protected int pageSize = 1; protected int start; protected int limit; protected String orderBy = null; protected String order = null; protected boolean autoCount = true; //-- --// protected List<T> result = Lists.newArrayList(); protected long totalCount = -1; private boolean success = true; //-- --// public Page() { } public Page(int pageSize) { this.pageSize = pageSize; } //-- ? --// /** * ??,??1,1. */ public int getPageNo() { return start / limit + 1; } /** * ??,??1,11. */ public void setPageNo(final int pageNo) { this.pageNo = pageNo; if (pageNo < 1) { this.pageNo = 1; } } /** * ??,??1,11. */ public void setPageStart(final int pageStart) { this.pageNo = pageStart / pageSize + 1; if (pageNo < 1) { this.pageNo = 1; } } public Page<T> pageNo(final int thePageNo) { setPageNo(thePageNo); return this; } /** * ??,1. */ public int getPageSize() { return limit; } /** * ??,11. */ public void setPageSize(final int pageSize) { this.pageSize = pageSize; if (pageSize < 1) { this.pageSize = 1; } } public Page<T> pageSize(final int thePageSize) { setPageSize(thePageSize); return this; } /** * ?pageNopageSize???,??1. */ public int getFirst() { //((pageNo - 1) * pageSize) + 1; return start; } /** * ?,.?','. */ public String getOrderBy() { return orderBy; } /** * ?,?','. */ public void setOrderBy(final String orderBy) { this.orderBy = orderBy; } public Page<T> orderBy(final String theOrderBy) { setOrderBy(theOrderBy); return this; } /** * ??. */ public String getOrder() { return order; } /** * ???. * * @param order ?descasc,?','. */ public void setOrder(final String order) { //order? String[] orders = StringUtils.split(StringUtils.lowerCase(order), ','); for (String orderStr : orders) { if (!StringUtils.equals(DESC, orderStr) && !StringUtils.equals(ASC, orderStr)) { throw new IllegalArgumentException("??" + orderStr + "??"); } } this.order = StringUtils.lowerCase(order); } public Page<T> order(final String theOrder) { setOrder(theOrder); return this; } /** * ??,. */ public boolean isOrderBySetted() { return (StringUtils.isNotBlank(orderBy) && StringUtils.isNotBlank(order)); } /** * ??count?, false. */ public boolean isAutoCount() { return autoCount; } /** * ??count?. */ public void setAutoCount(final boolean autoCount) { this.autoCount = autoCount; } public Page<T> autoCount(final boolean theAutoCount) { setAutoCount(theAutoCount); return this; } //-- --// /** * ?. */ public List<T> getResult() { return result; } /** * . */ public void setResult(final List<T> result) { this.result = result; } /** * ?, -1. */ public long getTotalCount() { return totalCount; } /** * . */ public void setTotalCount(final long totalCount) { this.totalCount = totalCount; } /** * ?pageSizetotalCount, -1. */ public long getTotalPages() { if (totalCount < 0) { return -1; } /*long count = totalCount / pageSize; if (totalCount % pageSize > 0) { count++; } return count;*/ long count = totalCount / this.getPageSize(); if (totalCount % this.getPageSize() > 0) { count++; } return count; } /** * ?. */ public boolean isHasNext() { return (pageNo + 1 <= getTotalPages()); } /** * ??, ??1. * ????. */ public int getNextPage() { if (isHasNext()) { return pageNo + 1; } else { return pageNo; } } /** * ?. */ public boolean isHasPre() { return (pageNo - 1 >= 1); } /** * ??, ??1. * ???. */ public int getPrePage() { if (isHasPre()) { return pageNo - 1; } else { return pageNo; } } public int getStart() { return start; } public void setStart(int start) { this.start = start; } public int getLimit() { return limit; } public void setLimit(int limit) { this.limit = limit; } public boolean isSuccess() { return success; } public void setSuccess(boolean success) { this.success = success; } }