dwr简介--一个例子(续)

public   class  TableModelBean  {
    
     // 表格的第一列
     public   static  final  int  COLUMN_1  =   0 ;
    
     // 表格的第二列
     public   static  final  int  COLUMN_2  =   1 ;
    
     // 表格的第三列
     public   static  final  int  COLUMN_3  =   2 ;

     // 每一列的排序升序降序标记 true升序,false降序
     private  boolean[] columnFlags  =   {  false ,  false ,  false  } ;
    
     // 表格分页总页面数
     private   int  totalPage  =   0 ;
    
     // 表格当前页
     private   int  currentPage  =   0 ;
    
     // 表格总行数
     private   int  rowsCount  =   0 ;

     // 没用
     private  String[] pagers  =   {  ""  } ;

     // 存放全体记录的容器
     private  List rows  =   new  ArrayList();

     // 存放当前记录的容器
     private  List currentPageRows  =   new  ArrayList();

     // 数据库操作类
     private   static  ModelOneDAO dao;

     // 每页记录数设为20
     private   static  final  int  PAGE_SIZE  =   20 ;

     // 初始排序行为第一行
     private   int  sortedColumn  =   1 ;

     /**/ /* *
     *  构造函数
      */
     public  TableModelBean()  {
        dao  =   new  ModelOneDAO();
        init();
    }

     /**/ /* *
     *  初始化
      */
     private   void  init()  {
         try   {
            rows  =  dao.getSortedRows(sortedColumn, columnFlags[sortedColumn]);
            setRowsCount(rows.size());
            setTotalPage(getTotalPageByRow(rows.size(), PAGE_SIZE));
            setCurrentPage( 1 );
        }   catch  (SQLException e)  {
             //  TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

     /**/ /* *
     * 返回当前页的内容
     * @return Returns the currentPage.
      */
     public   int  getCurrentPage()  {
         return  currentPage;
    }

     /**/ /* *
     * 设置当前页
     * @param currentPage
     *            The currentPage to set.
      */
     public   void  setCurrentPage( int  currentPage)  {
         this .currentPage  =  currentPage;

        currentPageRows.clear();
         int  firstIndex  =  PAGE_SIZE  *  (currentPage  -   1 );
         int  lastIndex  =  (firstIndex  +  PAGE_SIZE)  <  rowsCount  ?  firstIndex
                 +  PAGE_SIZE : rowsCount;
         for  ( int  i  =  firstIndex; i  <  lastIndex; i ++ )  {
            currentPageRows.add(rows. get (i));
        }
    }

     /**/ /* *
     * 取得所有行
     * @return Returns the rows.
      */
     public  List getRows()  {
         return  rows;
    }


     /**/ /* *
     * 取的分页数
     * @return Returns the totalPage.
      */
     public   int  getTotalPage()  {
        init();
         return  totalPage;
    }

     /**/ /* *
     * 设置分页数
     * @param totalPage
     *            The totalPage to set.
      */
     public   void  setTotalPage( int  totalPage)  {
         this .totalPage  =  totalPage;
    }

     /**/ /* *
     * 取得纪录数
     * @return Returns the totalRows.
      */
     public   int  getRowsCount()  {
         return  rowsCount;
    }

     /**/ /* *
     *    设置记录数
     *  @param totalRows
     *            The totalRows to set.
      */
     public   void  setRowsCount( int  rowsCount)  {
         this .rowsCount  =  rowsCount;
    }

     /**/ /* *
     * 取得当前页中的记录数
     * @return Returns the currentPageRows.
      */
     public  List getCurrentPageRows()  {
         return  currentPageRows;
    }

     /**/ /* *
     * 取得page页中的记录，当page大于totalPage时返回最后页
     * 因为是上面的getCurrentPageRows函数的重载，所以在dwr中不能正常使用。
     * 于是出现了getRowsByPageNo方法。
     * @param page
     * @return the currentPageRows.
      */
     public  List getCurrentPageRows( int  page)  {
        currentPageRows.clear();
         int  firstIndex  =  PAGE_SIZE  *  (page  -   1 );
         int  lastIndex  =  (firstIndex  +  PAGE_SIZE)  <  rowsCount  ?  firstIndex
                 +  PAGE_SIZE : rowsCount;
         for  ( int  i  =  firstIndex; i  <  lastIndex; i ++ )  {
            currentPageRows.add(rows. get (i));
        }
         return  currentPageRows;
    }

     /**/ /* *
     * 取得page页中的记录，当page大于totalPage时返回最后页
     * @param page
     * @return 包含当前页记录的List
      */
     public  List getRowsByPageNo( int  page)  {
        init();
        page  =  page  >  totalPage  ?  totalPage : page;
        List result  =   new  ArrayList();
         int  firstIndex  =  PAGE_SIZE  *  (page  -   1 );
         int  lastIndex  =  (firstIndex  +  PAGE_SIZE)  <  rowsCount  ?  firstIndex
                 +  PAGE_SIZE : rowsCount;
         for  ( int  i  =  firstIndex; i  <  lastIndex; i ++ )  {
            result.add(rows. get (i));
        }
         return  result;
    }

     /**/ /* *
     * 按照某一列进行排序，再返回当前页中的数据
     * @param currentPage
     * @param columnNo
     * @return the Rows of current Page that sorted by columnNo
      */
     public  List getCurrentPageSortedByColumnRows( int  currentPage,  int  columnNo)  {
        init();
        sortBy(columnNo);
        currentPageRows.clear();
         int  firstIndex  =   20   *  (currentPage  -   1 );
         int  lastIndex  =  (firstIndex  +   20 )  <  rowsCount  ?  firstIndex  +   20
                : rowsCount;
         for  ( int  i  =  firstIndex; i  <  lastIndex; i ++ )  {
            currentPageRows.add(rows. get (i));
        }
         return  currentPageRows;
    }

     /**/ /* *
     * 返回一个分页数组。用处不太大，客户端用Javascript也可以计算。
     * @return Returns the pages.
      */
     public  String[] getPagers()  {
        pagers  =   new  String[totalPage];
         for  ( int  i  =   1 ; i  <=  totalPage; i ++ )  {
            pagers[i  -   1 ]  =  i  +   "" ;
        }
         return  pagers;
    }

     /**/ /* *
     * 按照某一列进行排序
     * @param columnNo
      */
     public   void  sortBy( int  columnNo)  {
         this .sortedColumn  =  columnNo;
        columnFlags[columnNo]  =  ( ! columnFlags[columnNo]);
         try   {
            rows  =  dao.getSortedRows(columnNo, columnFlags[columnNo]);
        }   catch  (SQLException e)  {
             //  TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

     /**/ /* *
     * 删除某一列,按照主键(第一列)
     * @param key
     * @return
      */
     public  boolean deleteRow( int  key)  {
         try   {
            dao.deleteRow(key);
        }   catch  (SQLException e)  {
            e.printStackTrace();
             return   false ;
        }
         return   true ;
    }

     /**/ /* *
     * 要新增加一个数据前先计算出Id.
     * 这个例子只是用来演示用的,如果多人访问会出现并发问题
     * @return
      */
     public   int  getNextId()  {
         try   {
             return  dao.getNextId();
        }   catch  (SQLException e)  {
            e.printStackTrace();
             return   - 1 ;
        }
    }

     /**/ /* *
     * 增加一行
     * @param trb
     * @return
      */
     public  boolean addRow(TableRowBean trb)  {
         try   {
            dao.addRow(trb);
             return   true ;
        }   catch  (SQLException e)  {
            e.printStackTrace();
             return   false ;
        }
    }

     /**/ /* *
     * 更改一行
     * @param trb
     * @return
      */
     public  boolean updateRow(TableRowBean trb)  {
         try   {
            dao.updateRow(trb);
             return   true ;
        }   catch  (SQLException e)  {
            e.printStackTrace();
             return   false ;
        }
    }

     /**/ /* *
     * 按照key取回单行信息
     * @param key
     * @return
      */
     public  TableRowBean getSingleRow( int  key)  {
        TableRowBean row;
         try   {
            row  =  dao.getSingleRow(key);
        }   catch  (SQLException e)  {
            row  =   new  TableRowBean();
            e.printStackTrace();
        }
         return  row;
    }

     /**/ /* *
     * 辅助方法计算分页数
     * @param rowSize
     * @param pageSize
     * @return
      */
     private   static   int  getTotalPageByRow( int  rowSize,  int  pageSize)  {
         int  result  =   0 ;
        result  =  rowSize  %  pageSize  ==   0   ?  rowSize  /  pageSize : rowSize
                 /  pageSize  +   1 ;
         return  result;
    }
}

<? xml version="1.0" encoding="ISO-8859-1" ?>
<! DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
                         "http://java.sun.com/dtd/web-app_2_3.dtd" >
< web-app >
     < filter >
         < filter-name > EncodingFilter </ filter-name >
         < filter-class > org.mstar.strutsajax.EncodingFilter </ filter-class >
         < init-param >
                 < param-name > encoding </ param-name >
                 < param-value > gb2312 </ param-value >
         </ init-param >
     </ filter >
     < servlet >
         < servlet-name > action </ servlet-name >
         < servlet-class > org.apache.struts.action.ActionServlet </ servlet-class >
         < init-param >
             < param-name > config </ param-name >
             < param-value > /WEB-INF/struts-config.xml </ param-value >
         </ init-param >
         < load-on-startup > 1 </ load-on-startup >
     </ servlet >
     < servlet >
         < servlet-name > dwr-invoker </ servlet-name >
         < display-name > DWR Servlet </ display-name >
         < description > Direct Web Remoter Servlet </ description >
         < servlet-class > uk.ltd.getahead.dwr.DWRServlet </ servlet-class >
         < init-param >
             < param-name > config </ param-name >
             < param-value > WEB-INF/dwr.xml </ param-value >
         </ init-param >
         < init-param >
             < param-name > debug </ param-name >
             < param-value > true </ param-value >
         </ init-param >
         < load-on-startup > 1 </ load-on-startup >
     </ servlet >
     < servlet-mapping >
         < servlet-name > action </ servlet-name >
         < url-pattern > *.do </ url-pattern >
     </ servlet-mapping >
     < servlet-mapping >
         < servlet-name > dwr-invoker </ servlet-name >
         < url-pattern > /dwr/* </ url-pattern >
     </ servlet-mapping >
     < welcome-file-list >
         < welcome-file > index.jsp </ welcome-file >
         < welcome-file > login.jsp </ welcome-file >
     </ welcome-file-list >
     < taglib >
         < taglib-uri > /WEB-INF/struts-bean </ taglib-uri >
         < taglib-location > /WEB-INF/struts-bean.tld </ taglib-location >
     </ taglib >
     < taglib >
         < taglib-uri > /WEB-INF/struts-logic </ taglib-uri >
         < taglib-location > /WEB-INF/struts-logic.tld </ taglib-location >
     </ taglib >
     < taglib >
         < taglib-uri > /WEB-INF/struts-html </ taglib-uri >
         < taglib-location > /WEB-INF/struts-html.tld </ taglib-location >
     </ taglib >
</ web-app >

< servlet >
         < servlet-name > dwr-invoker </ servlet-name >
         < display-name > DWR Servlet </ display-name >
         < description > Direct Web Remoter Servlet </ description >
         < servlet-class > uk.ltd.getahead.dwr.DWRServlet </ servlet-class >
         < init-param >
             < param-name > config </ param-name >
             < param-value > WEB-INF/dwr.xml </ param-value >
         </ init-param >
         < init-param >
             < param-name > debug </ param-name >
             < param-value > true </ param-value >
         </ init-param >
         < load-on-startup > 1 </ load-on-startup >
     </ servlet >

<? xml version="1.0" encoding="UTF-8" ?>
<! DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 1.0//EN" "http://www.getahead.ltd.uk/dwr/dwr10.dtd" >

< dwr >
     < init >
         < converter  id ="tablerowbean"  class ="org.mstar.strutsajax.converter.TableRowConverter" />
       </ init >
     < allow >
         < create  creator ="new"  javascript ="UserLogic" >
             < param  name ="class"  value ="org.mstar.strutsajax.ajax.UserLogic" />
             < include  method ="validate" />
         </ create >
         < create  creator ="new"  javascript ="TableModel"  scope ="session" >
             < param  name ="class"  value ="org.mstar.strutsajax.form.TableModelBean" />
             < include  method ="sortBy" />
             < include  method ="getRowsCount" />
             < include  method ="getTotalPage" />
             < include  method ="setCurrentPage" />
             < include  method ="getCurrentPageRows" />
             < include  method ="getCurrentPageSortedByColumnRows" />
             < include  method ="getRowsByPageNo" />
             < include  method ="deleteRow" />
             < include  method ="getNextId" />
             < include  method ="addRow" />
             < include  method ="updateRow" />
             < include  method ="getSingleRow" />
         </ create >
         < convert  converter ="tablerowbean"  match ="org.mstar.strutsajax.form.TableRowBean" />
     </ allow >
</ dwr >

<? xml version="1.0" encoding="UTF-8" ?>
<! DOCTYPE weblogic-web-app PUBLIC "-//BEA Systems, Inc.//DTD Web Application 8.1//EN"    "http://www.bea.com/servers/wls810/dtd/weblogic810-web-jar.dtd" >
< weblogic-web-app >
     < jsp-descriptor >
         < jsp-param >
             < param-name > debug </ param-name >
             < param-value > true </ param-value >
         </ jsp-param >
     </ jsp-descriptor >
     < context-root > struts-ajax </ context-root >
</ weblogic-web-app >