spring mvc 分页

springmvcstringhibernatesessionlist

分页主要需要两个参数：

1、当前页是第几页

2、每页展示多少条数据

先写一个类来封装处理这两个参数:
[java] view plaincopy

    package com.smvc.annonation.utils; 
     
    import java.io.Serializable; 
    import java.util.List; 
     
    import org.apache.commons.lang.builder.ToStringBuilder; 
    import org.apache.commons.lang.builder.ToStringStyle; 
     
    public class ResultFilter<T> implements Serializable{ 
     
        private static final long serialVersionUID = 5472321653620726832L; 
     
        private final static int DEFAULT_NAVIGATOR_SIZE = 5; 
     
        //当前页 
        private int currentPage = 1; 
        //每页显示数量 
        private int pageSize = 5; 
         
        //总条数 
        private int totalCount; 
     
        private boolean havaNextPage; 
     
        private boolean havePrePage; 
     
        private int navigatorSize; 
         
        //存放查询结果用的list 
        private List<T> items; 
         
        public ResultFilter(){ 
             
        } 
         
        public ResultFilter(int totalCount, int pageSize, int currentPage) { 
            this(totalCount, pageSize, currentPage, DEFAULT_NAVIGATOR_SIZE); 
        } 
     
        public ResultFilter(int totalCount, int pageSize, int currentPage, 
                            int navigatorSize) { 
            this.totalCount = totalCount; 
            this.pageSize = pageSize; 
            this.currentPage = currentPage; 
            this.navigatorSize = navigatorSize; 
        } 
         
        public int getPageCount() { 
            int pageCount = 0; 
            if (pageSize != 0) { 
                pageCount = totalCount / pageSize; 
                if (totalCount % pageSize != 0) 
                    pageCount++; 
            } 
     
            return pageCount; 
        } 
     
        public int getCurrentPage() { 
            currentPage = currentPage < getPageCount() ? currentPage : 
                          getPageCount(); 
            currentPage = currentPage < 1 ? 1 : currentPage; 
     
            return currentPage; 
        } 
     
        public int getPageSize() { 
            return pageSize; 
        } 
     
        public int getTotalCount() { 
            return totalCount; 
        } 
     
     
        public boolean isHaveNextPage() { 
            havaNextPage = false; 
            if ((getPageCount() > 1) && (getPageCount() > getCurrentPage())) 
                havaNextPage = true; 
            return havaNextPage; 
        } 
     
        public boolean isHavePrePage() { 
            havePrePage = false; 
            if ((getPageCount() > 1) && (currentPage > 1)) 
                havePrePage = true; 
            return havePrePage; 
        } 
     
        private int getNavigatorIndex(boolean isBegin) { 
            int beginNavigatorIndex = getCurrentPage() - navigatorSize / 2; 
            int endNavigatorIndex = getCurrentPage() + navigatorSize / 2; 
            beginNavigatorIndex = beginNavigatorIndex < 1 ? 1 : beginNavigatorIndex; 
            endNavigatorIndex = endNavigatorIndex < getPageCount() ? 
                                endNavigatorIndex : 
                                getPageCount(); 
            while ((endNavigatorIndex - beginNavigatorIndex) < navigatorSize && 
                   (beginNavigatorIndex != 1 || endNavigatorIndex != getPageCount())) { 
                if (beginNavigatorIndex > 1) 
                    beginNavigatorIndex--; 
                else if (endNavigatorIndex < getPageCount()) 
                    endNavigatorIndex++; 
            } 
     
            if(isBegin) 
                return beginNavigatorIndex; 
            else 
                return endNavigatorIndex; 
        } 
     
        public int getBeginNavigatorIndex() { 
            return getNavigatorIndex(true); 
        } 
     
        public int getEndNavigatorIndex() { 
            return getNavigatorIndex(false); 
        } 
     
        public List<T> getItems() { 
            return items; 
        } 
     
        public void setItems(List<T> items) { 
            this.items = items; 
        } 
         
        public void setCurrentPage(int currentPage) { 
            this.currentPage = currentPage; 
        } 
     
        public void setPageSize(int pageSize) { 
            this.pageSize = pageSize; 
        } 
     
        public void setTotalCount(int totalCount) { 
            this.totalCount = totalCount; 
        } 
     
        @Override 
        public String toString() { 
            return ToStringBuilder.reflectionToString(this, ToStringStyle.MULTI_LINE_STYLE); 
        } 
     
    } 

接着，就要处理如何翻页的问题。解决方法就是在页面间传递参数，传递当前是第几页。

使用自己定义标签实现比较简便（由于现在只做了一个页面，并不能保证翻页功能的通用性，以后会慢慢完善）

自定义标签的配置:

my.tld
[html] view plaincopy

    <?xml version="1.0" encoding="UTF-8"?> 
    <taglib xmlns="http://java.sun.com/xml/ns/j2ee" 
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
            xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" 
            version="2.0"> 
     
        <description>My Tag Library</description> 
        <tlib-version>1.0</tlib-version> 
        <short-name>my</short-name> 
        <uri>my-taglib</uri> 
     
        <tag> 
            <description>split page</description> 
            <name>paging</name> 
            <tag-class>com.smvc.annonation.tag.PagingTag</tag-class> 
            <body-content>empty</body-content> 
            <attribute> 
                <description>base href</description> 
                <name>href</name> 
                <required>false</required> 
                <rtexprvalue>true</rtexprvalue> 
            </attribute> 
            <attribute> 
                <description>curr page</description> 
                <name>curr</name> 
                <required>true</required> 
                <rtexprvalue>true</rtexprvalue> 
            </attribute> 
            <attribute> 
                <description>page size</description> 
                <name>size</name> 
                <required>true</required> 
                <rtexprvalue>true</rtexprvalue> 
            </attribute> 
            <attribute> 
                <description>total page</description> 
                <name>total</name> 
                <required>true</required> 
                <rtexprvalue>true</rtexprvalue> 
            </attribute> 
            <attribute> 
                <description>curr parameter name</description> 
                <name>cparam</name> 
                <required>false</required> 
                <rtexprvalue>false</rtexprvalue> 
            </attribute> 
            <attribute> 
                <description>page size parameter name</description> 
                <name>sparam</name> 
                <required>false</required> 
                <rtexprvalue>false</rtexprvalue> 
            </attribute> 
            <dynamic-attributes>false</dynamic-attributes> 
        </tag> 
         
         
         
        <tag> 
            <description>front split page</description> 
            <name>frontPaging</name> 
            <tag-class>com.aspire.cms.demo.framework.tag.FrontPagingTag</tag-class> 
            <body-content>empty</body-content> 
            <attribute> 
                <description>base href</description> 
                <name>href</name> 
                <required>false</required> 
                <rtexprvalue>true</rtexprvalue> 
            </attribute> 
            <attribute> 
                <description>result filter</description> 
                <name>rf</name> 
                <required>true</required> 
                <rtexprvalue>true</rtexprvalue> 
            </attribute> 
            <dynamic-attributes>false</dynamic-attributes> 
        </tag> 
     
    </taglib> 

对应的java类：
[java] view plaincopy

    package com.smvc.annonation.tag; 
     
    import java.io.IOException; 
     
    import javax.servlet.jsp.JspException; 
    import javax.servlet.jsp.JspWriter; 
    import javax.servlet.jsp.tagext.SimpleTagSupport; 
     
    import org.apache.commons.lang.StringUtils; 
     
    public class PagingTag extends SimpleTagSupport { 
         
        private String href; 
         
        //当前页 
        private String cparam; 
        //每页条数 
        private String sparam; 
     
        private int curr;//当前页 
         
        private int size;//每页条数 
         
        private int total;//总页数 
         
        @Override 
        public void doTag() throws JspException, IOException { 
            JspWriter out = getJspContext().getOut(); 
             
            if(StringUtils.isEmpty(cparam)) { 
                cparam = "currentPage"; 
            } 
            if(StringUtils.isEmpty(sparam)) { 
                sparam = "pageSize"; 
            } 
             
            if(!href.endsWith("?") && !href.endsWith("&")) { 
                if(href.indexOf("?") == -1) { 
                    href = href + "?"; 
                } else { 
                    href = href + "&"; 
                } 
            } 
             
            if (curr <= 0) { 
                curr = 1; 
            } else if (curr > total) { 
                curr = total; 
            } 
             
            out.append("<span>"); 
            // 首页 
            if (curr == 1) { 
                out.append("首页"); 
            } else { 
                href(out, href, 1, "首页"); 
            } 
            out.append(" | "); 
            // 上一页 
            if (curr == 1) { 
                out.append("上一页"); 
            } else { 
                href(out, href, curr - 1, "上一页"); 
            } 
            out.append(" | "); 
            // 下一页 
            if (curr == total) { 
                out.append("下一页"); 
            } else { 
                href(out, href, curr + 1, "下一页"); 
            } 
            out.append(" | "); 
            // 末页 
            if (curr == total) { 
                out.append("末页"); 
            } else { 
                href(out, href, total, "末页"); 
            } 
            out.append("</span>"); 
            out.append("<span>第"); 
            out.append(curr + "/" + total); 
            out.append("页</span>"); 
             
             
            super.doTag(); 
        } 
         
        private void href(JspWriter out, String href, int curr, String title) throws IOException { 
            out.append("<a href="").append(href).append(cparam).append("=").append("" + curr).append("&").append(sparam).append("=").append("" + size).append("">").append(title).append("</a>"); 
        } 
     
        public int getCurr() { 
            return curr; 
        } 
     
        public void setCurr(int curr) { 
            this.curr = curr; 
        } 
     
        public int getTotal() { 
            return total; 
        } 
     
        public void setTotal(int total) { 
            this.total = total; 
        } 
     
        public String getHref() { 
            return href; 
        } 
     
        public void setHref(String href) { 
            this.href = href; 
        } 
     
        public String getCparam() { 
            return cparam; 
        } 
     
        public void setCparam(String cparam) { 
            this.cparam = cparam; 
        } 
     
        public String getSparam() { 
            return sparam; 
        } 
     
        public void setSparam(String sparam) { 
            this.sparam = sparam; 
        } 
     
        public int getSize() { 
            return size; 
        } 
     
        public void setSize(int size) { 
            this.size = size; 
        } 
     
    } 

在jsp中使用自定义的标签库来实现翻页功能：

list.jsp
[javascript] view plaincopy

    <%@ page language="java" contentType="text/html; charset=UTF-8" 
        pageEncoding="UTF-8" %> 
    <%@ page session="false"%> 
    <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
    <%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %> 
    <%@ taglib uri="my-taglib" prefix="my"%> 
    <title>学生列表</title> 
    <form action="list" method="post"> 
    <table> 
    <tr> 
        <td width="160">id</td> 
        <td width="160">姓名</td> 
        <td width="160">性别</td> 
        <td width="160">年龄</td> 
        <td width="160">生日</td> 
    </tr> 
    <c:forEach items="${rf.items}" var="student"> 
    <tr> 
        <td><c:out value="${student.id}"/></td> 
        <td><c:out value="${student.name}"/></td> 
        <td><c:out value="${student.gender}"/></td> 
        <td><c:out value="${student.age}"/></td> 
        <td><fmt:formatDate value="${student.birthday}"  type="both" pattern="yyyy-MM-dd"/></td> 
    </tr> 
    </c:forEach> 
    </table> 
    <my:paging curr="${rf.currentPage}" total="${rf.pageCount}" size="${rf.pageSize}" href="list"/> 
    </form> 

controller中根据参数对ResultFilter进行设置:
[java] view plaincopy

    @RequestMapping(value="/list") 
        public ModelAndView listStudent(@ModelAttribute ResultFilter<Student> rf){ 
            studentService.listStudent(rf); 
            return new ModelAndView("list", "rf", rf); 
        } 

service中的方法:
[java] view plaincopy

    public void listStudent(ResultFilter<Student> rf){ 
        rf.setTotalCount(getStudentCount()); 
        rf.setItems(studentDao.getListForPage("from Student", (rf.getCurrentPage() - 1 )* rf.getPageSize(), rf.getPageSize())); 
    } 

这个方法没有使用session,能支持多台服务器共同提供服务的情况。但是这个方法的效率可能有点低，因为每次翻页的时候都会重新创建一个ResultFilter，使用hibernate的缓存应该会使性能有所提高。