分页技术总结

分页在Web开发中是很常用的技术，下面介绍下最简单的分页实现：
首先介绍一下实现分页需要的类：
Page：分页信息类，封装了分页所需的所有信息，如每页显示记录数、总记录数、总页数、当前页、查询起始点、是否有上一页、是否有下一页。
PageUtil：分页辅助类，进行分页的时候，必须知道3个信息，分别是当前页、每页显示记录数、总记录数，其他信息都可以通过这三个信息计算得到。
Page类：

public class Page {    private int everyPage;      //每页显示记录数    private int totalCount;     //总记录数    private int totalPage;      //总页数    private int currentPage;    //当前页    private int beginIndex;     //查询起始点    private boolean hasPrePage;    //是否有上一页    private boolean hasNextPage;   //是否有下一页    public Page(int everyPage, int totalCount, int totalPage, int currentPage,            int beginIndex, boolean hasPrePage, boolean hasNextPage) {        super();        this.everyPage = everyPage;        this.totalCount = totalCount;        this.totalPage = totalPage;        this.currentPage = currentPage;        this.beginIndex = beginIndex;        this.hasPrePage = hasPrePage;        this.hasNextPage = hasNextPage;    }    public int getEveryPage() {        return everyPage;    }    public void setEveryPage(int everyPage) {        this.everyPage = everyPage;    }    public int getTotalCount() {        return totalCount;    }    public void setTotalCount(int totalCount) {        this.totalCount = totalCount;    }    public int getTotalPage() {        return totalPage;    }    public void setTotalPage(int totalPage) {        this.totalPage = totalPage;    }    public int getCurrentPage() {        return currentPage;    }    public void setCurrentPage(int currentPage) {        this.currentPage = currentPage;    }    public int getBeginIndex() {        return beginIndex;    }    public void setBeginIndex(int beginIndex) {        this.beginIndex = beginIndex;    }    public boolean isHasPrePage() {        return hasPrePage;    }    public void setHasPrePage(boolean hasPrePage) {        this.hasPrePage = hasPrePage;    }    public boolean isHasNextPage() {        return hasNextPage;    }    public void setHasNextPage(boolean hasNextPage) {        this.hasNextPage = hasNextPage;    }}

PageUtil类：

public class PageUtil {    public static Page createPage (int everyPage, int totalCount, int currentPage) {        everyPage = getEveryPage(everyPage);        currentPage = getCurrentPage(currentPage);        int totalPage = getTotalPage(everyPage, totalCount);        int beginIndex = getBeginIndex(everyPage, currentPage);        boolean hasPrePage = getHasPrePage(currentPage);        boolean hasNextPage = getNextPage(totalPage, currentPage);        return new Page(everyPage, totalCount, totalPage, currentPage,                 beginIndex, hasPrePage, hasNextPage);    }    public static int getEveryPage(int everyPage) {        return everyPage == 0 ? 10 : everyPage;    }    public static int getCurrentPage(int currentPage) {        return currentPage == 0 ? 1 : currentPage;    }    public static int getTotalPage(int everyPage, int totalCount) {        int totalPage = 0;        if (totalCount != 0 && totalCount%everyPage == 0) {            totalPage = totalCount/everyPage;        } else {            totalPage = totalCount/everyPage + 1;        }        return totalPage;    }    public static int getBeginIndex (int everyPage, int currentPage) {        return (currentPage - 1)*everyPage;    }    public static boolean getHasPrePage(int currentPage) {        return currentPage != 1 ? true : false;    }    public static boolean getNextPage(int totalPage, int currentPage) {        return totalPage == currentPage || totalPage == 0 ? false : true;    }}

在Controller中封装好Page，传入Service获取相应的数据，然后将数据列表和Page对象返回前台，
页面写法：

<div>        <c:choose>            <c:when test="${page.hasPrePage}">                <a href="xxx?currentPage=1">首页</a>                <a href="xxx?currentPage=${page.currentPage-1}">上一页</a>            </c:when>            <c:otherwise>首页|上一页</c:otherwise>        </c:choose>        <c:choose>            <c:when test="${page.hasNextPage}">                <a href="xxx?currentPage=${page.currentPage+1}">下一页</a>                <a href="xxx?currentPage=${page.totalPage}">尾页</a>            </c:when>            <c:otherwise>下一页|尾页</c:otherwise>        </c:choose>        当前为第${page.currentPage}页，共${page.totalPage}页    </div>

到此一个简单的分页实现完毕。