Java Web分页技术.doc

我们这里，先看从数据库中读取的情况操作数据库就需要tsql语句，mssqlserver2005新推出了一个row_number()很好用，还有就是mysql的limit也非常好使。mssqlserver2005的如下：select * from (select row_number() over (order by ename) as rn, f.* from emp f) b where b.rn between 6 and 10;mysql的：select * from emp limit 5，5mysql的应注意，使用limit时，表中必须用主键，还有limit后的两个参数分别代表（标识位，长度），标识位从0开始现在开始一步步完成，首先完成model模块，建立pagebeanimport java.util.*;public class PageBean private Collection objs;/从数据库中读的集合 private int totalCount;/总的条数 private int pageNo;/当前的页数 private int pageCount;/每页的条数 public int getPageCount() return pageCount; public void setPageCount(int pageCount) this.pageCount = pageCount; public void setPageNo(int pageNo) this.pageNo = pageNo; public int getTotalPage() if(totalCount % pageCount = 0) return totalCount/pageCount; else return totalCount/pageCount + 1; /多写一个判断下一页的方法 public boolean isNext() return pageNo 1; public Collection getObjs() return objs; public void setObjs(Collection objs) this.objs = objs; public int getPageNo() return pageNo; public int getTotalCount() return totalCount; public void setTotalCount(int totalCount) this.totalCount = totalCount; public PageBean(Collection objs, int totalCount, int pageNo, int pageCount) this.objs = objs; this.totalCount = totalCount; this.pageNo = pageNo; 之后开始实现biz模块我们写一个具体分页的逻辑import java.util.*;import java.sql.*;public class EmpBiz public EmpBiz() /具体实现分页的方法，传递两个参数，一个第几页，一个每页的数量 public PageBean listEmps(int pageNo, int pageCount) Connection con = null; Statement stmt = null; ResultSet rs = null; ArrayList emps = new ArrayList(); /次数我使用mssqlserver的方式，所以计算前后两个范围，用a，b表示 int a = pageNo* pageCount; int b = (pageNo-1)* pageCount; try Class.forName(com.microsoft.sqlserver.jdbc.SQLServerDriver); con=DriverManager.getConnection(jdbc:sqlserver:/localhost:1433;databaseName=Master;,sa,sa); stmt = con.createStatement(); rs = stmt.executeQuery(select * from (select row_number() over (order by ename) as rn, f.* from emp f) b where b.rn between +a+ and +b); while(rs.next() Employee e = new Employee(); e.setEmpno(rs.getInt(empno); e.setSal(rs.getDouble(sal); emps.add(e); rs = stmt.executeQuery(select count(*) from emp); int totalCount=0; if(rs.next() totalCount = rs.getInt(1); PageBean pageBean = new PageBean(emps,totalCount,pageNo,pageCount); return pageBean; catch (Exception ex) System.out.println(发生错误，错误是: + ex.getMessage(); return null; finally if(stmt != null) try stmt.close(); catch (SQLException ex1) if(con != null) try con.close(); catch (SQLException ex1) 实现完EmpBiz之后，开始写servlet类import java.io.*;import java.util.*;public class EmpServlet extends HttpServlet private static final String CONTENT_TYPE = text/html; charset=GBK; /Initialize global variables public void init() throws ServletException /Process the HTTP Get request public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException response.setContentType(CONTENT_TYPE); EmpBiz biz = new EmpBiz(); /给页数和每页数量一个初始值 int pageNo = 1; int pageCount = 5; String pageNoStr = request.getParameter(pageNo); String pageCountStr = request.getParameter(pageCount); if(pageNoStr != null) pageNo = Integer.parseInt(pageNoStr); if(pageCountStr != null) pageCount = Integer.parseInt(pageCountStr); PageBean pageBean = biz.listEmps(pageNo,pageCount); request.setAttribute(pageBean,pageBean); request.getRequestDispatcher(listemp.jsp).forward(request,response); /Process the HTTP Post request public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException doGet(request, response); /Clean up resources public void destroy() 业务逻辑完了之后，只要实现jsp页面即可listemp a color:blue; text-decoration=underline; cursor:pointer; function page(s) var myform = document.getEleme