周报2016.09.05-2016.09.11（分页查询并放入非datagrid列表）

这周说说分页查询，以前做的分页查询是原先工程里写好的，直接用，前台使用datagrid，给datagrid设置action的url，而后台使用封装好的pageQuery，只要自己写几句hql语句就可以实现。
后来要做一个新闻列表，样式就不能用datagrid这种表单了，而是要配合ul标签显示，所以干脆自己写个分页查询。
先说说分页查询的流程，分页查询浏览每一页数据都要向数据库查询出所有数据，然后后台操作取出当页的几条数据显示到页面中。

步骤一、先根据第一次查询获取总数据数。
DAO层：

public int getAllDocumentByKey(String key){        String hql="from WpsDocument where status='90' and title like '%'||?||'%'";        return getSession().createQuery(hql).setString(0, key).list().size();.    }

Service层：

public int getAllDocumentByKey(String key) {        return wpsDocumentDao.getAllDocumentByKey(key);    }

步骤二、根据总数据数和页容量计算总页数
DAO层：

public int getPageCount(int pageSize,String key) {        List<WpsDocument> list=this.getAllDocumentByKey(key);        int pageCount=0;        if (list.size()%pageSize==0) {            pageCount=list.size()/pageSize;        }else{            pageCount=(list.size()/pageSize)+1;        }        return pageCount;    }

Service层：

public int getPageCount(int pageSize, String key) {        return wpsDocumentDao.getPageCount(pageSize, key);    }

步骤三、根据返回的页数获取当前页的数据
Dao层：

public List<WpsDocument> getDocumentByKey(String key, int pageIndex,            int pageSize) {        Query query=getSession().createQuery("from WpsDocument  where status='90' and  title like '%'||?||'%' order by docid desc");        query.setString(0, key);        query.setFirstResult((pageIndex-1)*pageSize);        query.setMaxResults(pageSize);        return query.list();    }

Service层：

public List<WpsDocument> getDocumentByKey(String key, int pageIndex,            int pageSize) {        return wpsDocumentDao.getDocumentByKey(key, pageIndex, pageSize);    }

步骤四、返回至前台
Action层：

    public String getNewsListByKey() throws UnsupportedEncodingException{        int pageSize=10;        int pageIndex=1;        if(servletRequest.getParameter("pageIndex")!=null){            pageIndex=Integer.parseInt(servletRequest.getParameter("pageIndex"));        }        List<WpsDocument>  list=wpsDocumentService.getDocumentByKey(key, pageIndex, pageSize);        int size=wpsDocumentService.getAllDocumentByKey(key);        int pageCount=wpsDocumentService.getPageCount(pageSize, key);        getServletRequest().setAttribute("list", list);        getServletRequest().setAttribute("key", key);        getServletRequest().setAttribute("size", size);        getServletRequest().setAttribute("pageCount", pageCount);        getServletRequest().setAttribute("pageIndex", pageIndex);        return SUCCESS;    }

步骤五、前台列显示
Main.Jsp：

  <div class="newscenter_search">    <input type="text" class="search_key" id="key" value="请输入关键字" style="border:1px solid #ddd; "  onmouseover="this.style.borderColor='#00b8ee'" onmouseout="this.style.borderColor=''" onFocus="if (value =='请输入关键字'){value =''}" onBlur="if (value ==''){value='请输入关键字'}"/>    <a href="javascript:onclick=doQuery()"><img src="${pageContext.request.contextPath}/resource/images/newscenter_icon01.png"></a>  </div><div class="list_content">    <div class="list_cur_con">      <div class="list_curpos">当前位置:<em><a href="">新闻中心</a></em>><i><a href="">动态新闻</a></i></div>      <div class="list_backhome"><a class="list_home" href="${pageContext.request.contextPath}/news.action">新闻中心首页</a><a class="list_back" href="#" onClick="javascript:history.back(-1);">返回</a></div>    </div>    <ul>    <c:forEach items="${requestScope.list }" var="d">    <li><a href="${pageContext.request.contextPath}${d.publishpath}${d.docid}.html"><em>${d.title }</em><i><fmt:formatDate value="${d.createtime}" pattern="yyyy-M-d" /></i></a></li>     </c:forEach>    </ul>    <c:if test="${!empty requestScope.list }">    <div class="list_pages">共:<em>${size }</em>条信息，每页<em>10</em>条，当前第<em id="pag">${requestScope.pageIndex }</em>/<em>${pageCount}</em>页     <c:if test="${pageIndex=='1'}">    <span>首页</span>    <span>上页</span>    </c:if>    <c:if test="${pageIndex!='1'}">    <span><a href="javascript:onclick=skipPage(1,'${requestScope.key }')">首页</a></span>    <span><a href="javascript:onclick=skipPrev('${requestScope.pageIndex-1 }','${requestScope.key }')">上页</a></span>    </c:if>    <c:if test="${pageIndex==pageCount}">      <span>下页</span>    <span>末页<span>    </c:if>    <c:if test="${pageIndex!=pageCount}">     <span><a href="javascript:onclick=skipNext('${requestScope.pageIndex+1 }','${requestScope.pageCount }','${requestScope.key }')">下页</a></span>    <span><a href="javascript:onclick=skipPage('${requestScope.pageCount }','${requestScope.key }')">末页</a></span>    </c:if>    <span>      转到 <input type="text" id="jumpNumTxt"  style="width: 20px;" name="jumpNumTxt"/> 页                             <input type="button"  value="跳转"                                 onclick="jumpPage('${requestScope.pageCount }','${requestScope.key }')" />                                </span></div>                                </c:if></div><script type="text/javascript">function skipPrev(pageIndex,key){    if(pageIndex==0){    alert('当前已经是第一页！');    }else{        location.href="newslistbykey.action?pageIndex="+pageIndex+"&key="+key;    }    }function skipNext(pageIndex,pageCount,key){    if(parseInt(pageIndex)>parseInt(pageCount)){    alert('当前已经是最后一页！');    }else{        location.href="newslistbykey.action?pageIndex="+pageIndex+"&key="+key;    }    }function skipPage(pageIndex,key){    location.href="newslistbykey.action?pageIndex="+pageIndex+"&key="+key;    }function jumpPage(pageCount,key){    var pageIndex=document.getElementById("jumpNumTxt").value;    if(pageIndex<=pageCount&&pageIndex>0){    location.href="newslistbykey.action?pageIndex="+pageIndex+"&key="+key;    }else if(pageIndex>pageCount||pageIndex<=0){    alert('跳转页面超出范围!');    document.getElementById("jumpNumTxt").value="";    return;    }else{    alert('页面跳转输入不规范！');    document.getElementById("jumpNumTxt").value="";    return;    }    }function doQuery(){var key=document.getElementById("key").value;key=$.trim(key);if(key==null||key==""){alert("请输入关键词！");document.getElementById("key").value="";    return;}location.href="newslistbykey.action?key="+key;}</script>