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displaytag在struts中完成大数据量分页显示

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应用displaytag在struts中完成大数据量分页显示,Oracle 数据库

 

JSP文件:

 

<% @ taglib uri = " /WEB-INF/displaytag.tld " prefix = " disp " %>

< disp:table name ="resultList" export ="true" pagesize ="100" requestURI ="logQueryAction.do" sort ="external" id ="element" partialList ="true" size ="resultSize" >
          
< disp:column property ="operdate" title ="操作时间" ></ disp:column >
          
< disp:column property ="pername" title ="操作人员" ></ disp:column >
          
< disp:column property ="opertype" title ="操作类型" ></ disp:column >
</ disp:table >
...

 

name="resultList" 将记录集存在session或者request中的键值
export="true" 是否显示导出选项
pagesize="100" 每页显示100条数据
requestURI="logQueryAction.do" struts中action的名称,如果记录少,可以直接分页
sort="external" 外部排序
id="element"   表格id值,用于程序得相关的参数
partialList="true" 分段从数据库中读数据
size="resultSize" 记录的总条数,用于计算总页数

 

struts action:

 

String pageIndexName = new org.displaytag.util.ParamEncoder( " element " ).encodeParameterName(org.displaytag.tags.TableTagParameters.PARAMETER_PAGE);   // 页数的参数名
        
int pageSize = 100 ;   //每页显示的条数
        
int pageIndex = GenericValidator.isBlankOrNull(request.getParameter(pageIndexName)) ? 0 :(Integer.parseInt(request.getParameter(pageIndexName)) - 1 ); //当前页数
String sqlCount
= " select count(*)   from user_log a " ; //用于统计总记录数的sql语句
         String sql
= " select * from (select rownum as rid, t1.* from (select b.pername as pername,to_char(a.operdate,'yyyy-mm-dd hh24:mi:ss') as operdate, " +
                
" decode(a.opertype,'D','删除','M','修改','其他') as opertype, a.hphm as hphm from user_log a, " +
                
" (select asuser.userid as userid,nvl(asempmsg.pername,asuser.loginname) as pername from asuser,ASEMPMSG where asuser.perid=ASEMPMSG.perid(+)) b " +
                
" where a.userid=b.userid " ;    //查询语句
            //构造查询条件
         StringBuffer sb
= new StringBuffer();
        
if (logQueryForm.getCzrqStart() != null && ! "" .equals(logQueryForm.getCzrqStart())) {
             sb.append(
" and a.operdate > to_date(' " + logQueryForm.getCzrqStart() + " ','yyyy-mm-dd') " );
         }

        
if (logQueryForm.getCzrqEnd() != null && ! "" .equals(logQueryForm.getCzrqEnd())) {
             sb.append(
" and a.operdate <= to_date(' " + logQueryForm.getCzrqEnd() + " ','yyyy-mm-dd') " );
         }

        
if (logQueryForm.getCzlx() != null && ! "" .equals(logQueryForm.getCzlx())) {
             sb.append(
" and a.opertype = ' " + logQueryForm.getCzlx() + " ' " );
         }

        
if (logQueryForm.getCzry() != null && ! "" .equals(logQueryForm.getCzry())) {
             sb.append(
" and a.userid = ' " + logQueryForm.getCzry() + " ' " );
         }

     

         sqlCount
+= sb.toString();
         sql
+= sb.toString() + " order by a.operdate desc) t1 where rownum<= "
                        
+ (pageIndex + 1 ) * pageSize + " ) t2 where t2.rid> " + pageIndex * pageSize; //分页读取语句
        
        
// System.out.println(sb.toString());
         DBBean db = new DBBean();
         ResultSet rs
= null ;
         PreparedStatement prep
= null ;
        
try {
             List resultList
= db.getResultList(sql);   //将ResultSet保存在List里返回
             request.setAttribute(
" resultList " ,resultList); //把结果存入request
             prep
= db.getConnection().prepareStatement(sqlCount);   
             rs
= prep.executeQuery();
            
if (rs.next()) ... {
                 request.setAttribute(
" resultSize " , new Integer(rs.getInt( 1 )));     //将总记录数保存成Intger实例保存在request中
             }

         }

        
catch (Exception ex) {
             ex.printStackTrace();
         }

        
finally {
            
if (db != null ) ... {
                 db.closeConnection();    //关闭连接
             }

         }
... ... ... ... ... ... ...

 

其中的页面导航是英文的,只要修改org.displaytag.properties.TableTag.properties配置文件就可以把 英文改成中文。同时还可以指定导出文件的类型以及文件名。

export.excel = true
export.excel.label
= <span class = " export excel " >Excel </span>
export.excel.include_header
= true
export.excel.filename
= export.xls

如果不指定文件名,在点击导出excel的时候,就会在ie窗口中打开excel文件。很烦人!
指定文件名后就可以选择保存和打开了。

如果不指定文件名,在点击导出excel的时候,就会在ie窗口中打开excel文件。很烦人!

这个问题在1.1好象已经解决,display会默认以table的名字做为excel文件的名称。
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