Java 分页工具

[背景] 最近学习Spring MVC，涉及到分页显示的问题，准备自己整理一个分页工具。由于以前使用Strus框架使用 NewPandaKing 的一个PageBean和Page方法，耦合性比较高，于是优化一下。

[优点] 耦合低，使用方便。

[缺点] 由于耦合低，不查数据库，所以每次使用List的sublist方法，效率降低。

代码如下：

分页工具类：PageUtil.java

 

/**
 * Java 分页工具类
 */
package com.common.tool.util;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author neuhxy
 * @version 2015-4-23 15:25:21
 *
 */
public class PageUtil {

    private int page = 1; // 当前页
    public int total = 0; // 总页数
    private int size = 10; // 每页5条数据
    private int slice = 5; // 切片，当页大于切片时，进行分页处理
    private int totalRows = 0; // 总数据数
    private int pageStartRow = 0;// 每页的起始数
    private int pageEndRow = 0; // 每页显示数据的终止数
    private boolean hasNextPage = false; // 是否有下一页
    private boolean hasPreviousPage = false; // 是否有前一页
    private List<?> list; // 分页组件包含的集合
    private List<?> show; // 分页中需要显示的List
    private String action; // 设置跳转URL
    private String method = "GET"; // 使用POST或者GET请求
    @SuppressWarnings("unused")
    private String code1; // 分页组件的现实代码
    @SuppressWarnings("unused")
    private String code2; // 分页组件的现实代码
    private Map<String, Object> map = new HashMap<String, Object>(); // 隐含条件
    public int[] sizeArray = { 10, 20, 50, 100, 1000, 5000 }; // 设置几种可以显示的条数

    // 默认构造函数
    public PageUtil() {
    }

    /**
     * 分页初始化
     * 
     * @param list
     * @param size
     */
    public void init(List<?> initList, int pageSize) {
        if (null != initList) {

            this.setSize(pageSize);
            this.setList(initList);

            totalRows = initList.size();

            hasPreviousPage = false;

            if ((totalRows % this.getSize()) == 0) {
                total = totalRows / this.getSize();
            } else {
                total = totalRows / this.getSize() + 1;
            }

            if (page >= total) { hasNextPage = false; } else { hasNextPage = true; }

            if (totalRows < this.getSize()) {
                this.pageStartRow = 0;
                this.pageEndRow = totalRows;
            } else {
                this.pageStartRow = 0;
                this.pageEndRow = this.getSize();
            }
            this.setShow(getShow(this.getPage()));
        }

    }

    // 第一种样式 <ul> / <li> 格式
    public String getCode1() {

        StringBuffer sb = new StringBuffer();
        sb.append("<form style='text-align:center;' action="" + getAction() + "" method="" + getMethod() + "">");
        sb.append("<ul class="pagination">");

        // 判断是否有上一页
        if (isHasPreviousPage()) {
            sb.append("<li><a href="" + getAction() + "?page=1">&laquo;</a></li>");
            sb.append("<li><a href="" + getAction() + "?page=" + (getPage() - 1) + "">&lt;</a></li>");
        } else {
            sb.append("<li class="disabled"><a href="#">&laquo;</a></li>");
            sb.append("<li class="disabled"><a href="#">&lt;</a></li>");
        }

        // 中间显示
        // 当总页数大于切片时，才显示 ... 分页效果
        if (getTotal() > getSlice()) {
            
            // 如果当前页码在 1 - getSlice()，显示右侧 ... 翻页按钮
            if (getPage() > 0 && getPage() <= getSlice()
                    && getPage() < getTotal() - getSlice()) {
                for (int i = 1; i <= getSlice(); i++) {
                    String spanClzz = "<li><a href="" + getAction() + "?page=" + i + ""> " + i + " <span class="sr-only">(current)</span></a></li>";

                    if (this.page == i) {
                        spanClzz = "<li class="active"><a href="#">" + i + " <span class="sr-only">(current)</span></a></li>";
                    }
                    sb.append(spanClzz);
                    // 当总页数大于3 的时候 添加右侧 ... 分页
                }
                if (getTotal() > getSlice() +1 ) {
                    String dotClzz = "<li><a href="" + getAction() + "?page=" + (getSlice() +1) + ""> ... <span class="sr-only">(current)</span></a></li>";
                    sb.append(dotClzz);
                }

            }
            // 如果当前页码在6 到 total - 6 页，显示两端的两个 ...翻页按钮
            if (getPage() > getSlice() && getPage() <= getTotal() - getSlice()) {
                String dotClzz = "<li><a href=""
                        + getAction()
                        + "?page="
                        + (getPage() - ((getSlice() + 1) / 2))
                        + ""> ... <span class="sr-only">(current)</span></a></li>";
                sb.append(dotClzz);
                for (int i = getPage() - ((getSlice() - 1) / 2); i <= getPage()
                        + ((getSlice() - 1) / 2); i++) {
                    String spanClzz = "<li><a href=""
                            + getAction()
                            + "?page="
                            + i
                            + ""> "
                            + i
                            + " <span class="sr-only">(current)</span></a></li>";

                    if (this.page == i) {
                        spanClzz = "<li class="active"><a href="#">"
                                + i
                                + " <span class="sr-only">(current)</span></a></li>";
                    }
                    sb.append(spanClzz);
                    // 当总页数大于getSlice() 的时候 添加右侧 ... 分页

                }
                dotClzz = "<li><a href=""
                        + getAction()
                        + "?page="
                        + (getPage() + ((getSlice() + 1) / 2))
                        + ""> ... <span class="sr-only">(current)</span></a></li>";
                sb.append(dotClzz);

            }
            // 如果当前页码在total-getSlice() 到 total 页，左侧显示一个...翻页按钮
            if (getPage() > 0 && getPage() > getTotal() - getSlice()
                    && getPage() <= getTotal()) {

                String dotClzz = "<li><a href=""
                        + getAction()
                        + "?page="
                        + (getTotal() - getSlice())
                        + ""> ... <span class="sr-only">(current)</span></a></li>";
                sb.append(dotClzz);
                int s = getTotal() - getSlice() + 1 > 0 ? getTotal()
                        - getSlice() + 1 : 1;
                for (int i = s; i <= getTotal(); i++) {
                    String spanClzz = "<li><a href=""
                            + getAction()
                            + "?page="
                            + i
                            + ""> "
                            + i
                            + " <span class="sr-only">(current)</span></a></li>";

                    if (this.page == i) {
                        spanClzz = "<li class="active"><a href="#">"
                                + i
                                + " <span class="sr-only">(current)</span></a></li>";
                    }
                    sb.append(spanClzz);
                }

            }
        } else {
            // 否则直接显示，有几页显示几页，不加...
            for (int i = 1; i <= getTotal(); i++) {
                String spanClzz = "<li><a href="" + getAction() + "?page=" + i
                        + ""> " + i
                        + " <span class="sr-only">(current)</span></a></li>";

                if (this.page == i) {
                    spanClzz = "<li class="active"><a href="#">"
                            + i
                            + " <span class="sr-only">(current)</span></a></li>";
                }
                sb.append(spanClzz);
                // 当总页数大于getSlice() 的时候 添加右侧 ... 分页

            }
        }

        // 判断是否有下一页
        if (isHasNextPage()) {
            sb.append("<li><a href="" + getAction() + "?page="
                    + (getPage() + 1) + "">&gt;</a></li>");
            sb.append("<li><a href="" + getAction() + "?page=" + getTotal()
                    + "">&raquo;</a></li>");
        } else {
            sb.append("<li class="disabled"><a href="#">&gt;</a></li>");
            sb.append("<li class="disabled"><a href="#">&raquo;</a></li>");
        }

        sb.append("</ul></form>");
        return sb.toString();
    }

    // 第二种分页样式 <a> 带分页现实多少条记录设置
    public String getCode2() {

        StringBuffer sb = new StringBuffer();
        String code = "<div class="pager clearfix text-center">";
        String scripts = "<script> " + "function subPage(p){"
                + "document.pageForm.elements['page'].value = p;"
                + "document.pageForm.submit();" + "} "
                + " function subPageSize(pageSize){ "
                + " document.pageForm.submit();" + "}</script>";

        setMethod("POST");
        code += "<form name="pageForm" action="" + getAction()
                + "" method="" + getMethod() + "">";

        String hidden = "<input type="hidden" name="page" value="" + page
                + "">";
        if (!map.isEmpty()) {
            for (String key : map.keySet()) {
                System.out.println("key= " + key + " and value= "
                        + map.get(key));
                hidden += "<input type="hidden" name="" + key
                        + "" value="" + map.get(key) + "" />";
            }
        }
        code += hidden;
        code += scripts;

        // 底面样式 首页 上一页
        if (getPage() != 1) {
            code += "<a href="javascript:subPage(1)">首页</a> "
                    + "<a href="javascript:subPage(" + (this.getPage() - 1)
                    + ")">上一页</a> ";
        } else {
            code += "<span>首页</span> " + "<span>上一页</span> ";
        }

        // 跳第几页
        code += "第<select style="60px;" onchange="javascript:subPage(this.value)" class="numbox">";
        for (int i = 1; i <= getTotal(); i++) {
            if (i == this.getPage()) {
                code += "<option value=" + i + " selected='selected'>" + i
                        + "</option>";
            } else {
                code += "<option value=" + i + ">" + i + "</option>";
            }
        }
        code += "</select>页，共" + this.getTotal() + "页";

        // 每页显示几个记录
        code += "，每页显示<select style="60px;" name="size" onchange="javascript:subPageSize(this.value)" class="numbox">";
        for (int j = 0; j < sizeArray.length; j++) {
            if (sizeArray[j] == getSize()) {
                code += "<option value=" + sizeArray[j]
                        + " selected='selected'>" + sizeArray[j] + "</option>";
            } else {
                code += "<option value=" + sizeArray[j] + ">" + sizeArray[j]
                        + "</option>";
            }
        }

        code += "</select>条记录";

        // 下一页 尾页
        if (getPage() != getTotal()) {
            code += "<a href="javascript:subPage(" + (getPage() + 1)
                    + ")">下一页</a> " + "<a href="javascript:subPage("
                    + getTotal() + ")">尾页</a>";
        } else {
            code += "<span>下一页</span> " + "<span>尾页</span> ";
        }
        code += "</div>";
        sb.append(code);
        sb.append("</form>");
        return sb.toString();
    }

    // 判断要不要分页
    public boolean isNext() {
        return list.size() > getSlice();
    }

    public void setHasPreviousPage(boolean hasPreviousPage) {
        this.hasPreviousPage = hasPreviousPage;
    }

    // 获取下一个内容
    public List<?> getNextPage() {
        page = page + 1;
        disposePage();
        return getShow(page);
    }

    // 处理分页
    private void disposePage() {
        if (page == 0) {
            page = 1;
        }
        if ((page - 1) > 0) {
            hasPreviousPage = true;
        } else {
            hasPreviousPage = false;
        }

        if (page >= total) {
            hasNextPage = false;
        } else {
            hasNextPage = true;
        }
    }

    // 获取上一页内容
    public List<?> getPreviousPage() {
        page = page - 1;

        if ((page - 1) > 0) {
            hasPreviousPage = true;
        } else {
            hasPreviousPage = false;
        }
        if (page >= total) {
            hasNextPage = false;
        } else {
            hasNextPage = true;
        }
        return getShow(page);
    }

    public List<?> getShow() {
        return show;
    }

    // 获取第 n 页内容
    public List<?> getShow(int page) {

        if (page == 0) {
            this.setPage(1);
            page = 1;
        } else {
            this.setPage(page);
        }

        this.disposePage();

        if (page * size < totalRows) {// 判断是否为最后一页
            pageEndRow = page * size;
            pageStartRow = pageEndRow - size;
        } else {
            pageEndRow = totalRows;
            pageStartRow = size * (total - 1);
        }

        List<?> show = null;
        if (!list.isEmpty()) {
            show = list.subList(pageStartRow, pageEndRow);
        }
        return show;
    }

    // 获取第一页内容
    public List<?> getFistPage() {
        if (this.isNext()) {
            return list.subList(0, size);
        } else {
            return list;
        }
    }

    public int getPage() {
        return page;
    }

    public void setPage(int page) {
        this.page = page;
    }

    public int getTotal() {
        return total;
    }

    public void setTotal(int total) {
        this.total = total;
    }

    public int getSize() {
        return size;
    }

    public void setSize(int size) {
        this.size = size;
    }

    public int getTotalRows() {
        return totalRows;
    }

    public void setTotalRows(int totalRows) {
        this.totalRows = totalRows;
    }

    public int getPageStartRow() {
        return pageStartRow;
    }

    public void setPageStartRow(int pageStartRow) {
        this.pageStartRow = pageStartRow;
    }

    public int getPageEndRow() {
        return pageEndRow;
    }

    public void setPageEndRow(int pageEndRow) {
        this.pageEndRow = pageEndRow;
    }

    public boolean isHasNextPage() {
        return hasNextPage;
    }

    public void setHasNextPage(boolean hasNextPage) {
        this.hasNextPage = hasNextPage;
    }

    public List<?> getList() {
        return list;
    }

    public void setList(List<?> list) {
        this.list = list;
    }

    public boolean isHasPreviousPage() {
        return hasPreviousPage;
    }

    public String getAction() {
        return action;
    }

    public void setAction(String action) {
        this.action = action;
    }

    public String getMethod() {
        return method;
    }

    public void setMethod(String method) {
        this.method = method;
    }

    public Map<String, Object> getMap() {
        return map;
    }

    public void setMap(Map<String, Object> map) {
        this.map = map;
    }

    public void setShow(List<?> show) {
        this.show = show;
    }

    public void setCode1(String code1) {
        this.code1 = code1;
    }

    public void setCode2(String code2) {
        this.code2 = code2;
    }

    public int getSlice() {
        return slice;
    }

    public void setSlice(int slice) {
        this.slice = slice;
    }

    public int[] getSizeArray() {
        return sizeArray;
    }

    public void setSizeArray(int[] sizeArray) {
        this.sizeArray = sizeArray;
    }

}

Spring-MVC Controller部分： UserController.java

@RequestMapping("view_user")
    public String view_user(PageUtil p, HttpServletRequest request) {
        //……仅提供部分关键代码    
        //分页组件用法：首先获取所有List

        List<User> list = userService.getUserList();
        pu.init(list, pu.getSize());
        pu.setShow(pu.getShow(p.getPage()));
                //告诉分页跳转URL, 对应这个方法本身的路径
        pu.setAction("../user/view_user");
        request.setAttribute("pu", pu);

        return "admin/view_user";
    }

在页面上显示部分：view_user.jsp

<c:if test="${!empty pu.show}">
    <c:forEach items="${pu.show}" var="item">
                <td>${item.id }</td>
                 <!--显示具体内容-->
    </c:forEach>
</c:if>
<!-- 以下两种方式任选其一 -->
<!--显示分页代码1 使用Bootstrap 库样式 需要额外引入bootstrap.css -->
${pu.code1}
<!--显示分页代码1, 使用默认样式， 功能全 -->
${pu.code2}

参考资料：

[1] http://www.cnblogs.com/wenqiangwu/archive/2013/01/21/page_util.html　　

效果预览：