重构Struts2 JSP分页.doc

前两天的Struts2 JSP分页由于过于关注框架实现，导致结构比较混乱。经过一些改动，再次发布。环境是JDK1.6+mysql5.0+jboss4.0+struts 2.0.11已经实现上一版没实现的功能。首先来看UML图,为了简洁性，其中的setter & getter并没有标出。public classShowActionextendsActionSupport privateintcurrentPage = 1; privateinttotalPages; privatebooleanhasNext =false; privatebooleanhasPre = false; private ArrayList pageContentList; private ArrayList indexList private PageRetrieval pr; public String execute() init(); returnSUCCESS; privatevoid init() pr = new PageRetrieval(currentPage); setPageContentList(pr.getPageContentList(); setndexList(pr.getIndexList(); setHasNext(pr.getHasNext(); setHasPre(pr.getHasPre(); setTotalPages(pr.getTotalPages(); /other getters and setters publicclass PageRetrieval private PageInformation pi; public PageRetrieval(int currentPage) pi = new PageInformationFactory().create(currentPage); publicint getTotalPages() returnpi.getPti().getTotalPages(); /other getters and setters publicclass PageInformationFactory private DatabaseServices dataServ; public PageInformationFactory() dataServ = MyDatabaseServices.getInstance(); public PageInformation create(int currentPage) PageInformation pi = new PageInformation(); PageTotalInfo pti = getNewPageTotalInfo(); pi.setPti(pti); if(currentPage pti.getTotalPages() pi.setHasNext(true); if(currentPage !=1) pi.setHasPre(true); pi.setPageContentList(MyDatabaseServices)dataServ).getPageContent(currentPage, pti.getPageSize(); ArrayList indexTemp = getIndexList(currentPage,pti.getTotalPages(); pi.setIndexList(indexTemp); return pi; 本文来自哈客部落 Hake.cc private PageTotalInfo getNewPageTotalInfo() int pageSize = 20; int totalRows = (MyDatabaseServices)dataServ).getRowCount(); int totalPages = (totalRows + pageSize-1)/pageSize; returnnew PageTotalInfo(pageSize,totalPages,totalRows); private ArrayList getIndexList(int currentPage,int totalPages) int up = 0; if(currentPage+20)=totalPages) up = currentPage+20; else up = totalPages+1; ArayList result = new ArrayList(); for(int i=currentPage ;iup; i+) PageIndex temp = new PageIndex(i); result.add(temp); return result; publicclass PageInformation privateintcurrentPage; privatebooleanhasNext = false; privatebooleanhasPre = false; private ArrayList pageContentList; private ArrayList indexList; private PageTotalInfo pti; /other getters and setters publicclass MyDatabaseServices implements DatabaseServices private DataSource ds; private InitialContext ic; private Connection conn; private PreparedStatement ps; private ResultSet rs; privatestatic MyDatabaseServices dgs = new MyDatabaseServices(); private MyDatabaseServices()/use singleton pattern, so the constructor is private try ic = new InitialContext (); ds = (DataSource)ic.lookup(java:jdbc/jsp);/get database source catch(NamingException e) public Connection getConnection() try returnds.getConnection(); catch(SQLException e) e.printStackTrace(); returnnull; public void closeConnection(ResultSet rs,PreparedStatement ps,Connection conn) try if(rs!=null) rs.close(); if(ps!=null) ps.close(); if(conn!=null) conn.close(); catch(SQLException e ) e.printStackTrace(); public ArrayList getPageContent(int currentPage,int pageSize) ArrayList list=new ArrayList(); conn = getConnection(); try ps = conn.prepareStatement(SELECT * FROM jsptest LIMIT ?,?); int temp = (currentPage-1)*20; ps.setInt(1, temp); ps.setInt(2, pageSize); rs = ps.executeQuery(); while (rs.next() User user = new User(); user.setId(rs.getString(1); user.setName(rs.getString(2); list.add(user); return list; catch(SQLException e) e.printStackTrace(); finally dgs.closeConnection(rs, ps, conn); returnnull; publicint getRowCount() conn = getConnection(); try ps = conn.prepareStatement(SELECT * FROM jsptest); rs = ps.executeQuery(); rs.last(); int result = rs.getRow(); rs.first(); return result; 本文来自哈客部落 Hake.cc public Connection getConnection() try returnds.getConnection(); catch(SQLException e) e.printStackTrace(); returnnull; public void closeConnection(ResultSet rs,PreparedStatement ps,Connection conn) try if(rs!=null) rs.close(); if(ps!=null) ps.close(); if(conn!=null) conn.close(); catch(SQLException e ) e.printStackTrace(); public ArrayList getPageContent(int currentPage,int pageSize) ArrayList list=new ArrayList(); conn = getConnection(); try ps = conn.prepareStatement(SELECT * FROM jsptest LIMIT ?,?); int temp = (currentPage-1)*20; ps.setInt(1, temp); ps.setInt(2, pageSize); rs = ps.executeQuery(); while (rs.next() User user = new User(); user.setId(rs.getString(1); user.setName(rs.getString(2); list.add(user); return list; catch(SQLException e) e.printStackTrace(); finally dgs.closeConnection(rs, ps, conn); returnnull; publicint getRowCount() conn = getCon