简单分页（只有第一页、上一页、下一页、末一页）

DB.java代码：

 

package com.bjsxt.bbs;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DB {
 public static Connection getConn() {
  Connection conn = null;
  try {
   Class.forName("com.mysql.jdbc.Driver");
   conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bbs", "root" , "root");
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return conn;
 }
 
 public static Statement createStmt(Connection conn) {
  Statement stmt = null;
  try {
   stmt = conn.createStatement();
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return stmt;
 }
 
 public static ResultSet executeQuery(Statement stmt, String sql) {
  ResultSet rs = null;
  try {
   rs = stmt.executeQuery(sql);
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return rs;
 }
  
 public static  int executeUpdate(Connection conn, String sql){
  int ret = 0;
  Statement stmt = null;
  try {
   stmt = conn.createStatement();
   ret = stmt.executeUpdate(sql);
  } catch (SQLException e) {
   e.printStackTrace();
  } finally {
   close(stmt);
  }
  return ret ;
 }
 
 public static PreparedStatement prepareStmt(Connection conn, String sql){
  PreparedStatement pStmt = null;
  try {
   pStmt = conn.prepareStatement(sql);
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return pStmt;
 }
 
 public static PreparedStatement prepareStmt(Connection conn, String sql, int autoGeneratedKeys){
  PreparedStatement pStmt = null;
  try{
   pStmt  = conn.prepareStatement(sql, autoGeneratedKeys);
  } catch(SQLException e) {
   e.printStackTrace();
  }
  return pStmt;
 }
 
 public static void close(Connection conn) {
  if(conn != null) {
   try {
    conn.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
   conn = null;
  }
 }
 
 public static void close(Statement stmt) {
  if(stmt != null) {
   try {
    stmt.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
   stmt = null;
  }
 }
 
 public static void close(ResultSet rs) {
  if(rs != null) {
   try {
    rs.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
   rs = null;
  }
 }
}

 

Article.java代码：

package com.bjsxt.bbs;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Date;

public class Article {
 private int id;
 private int pid; //private Article parent
 private int rootId;
 private String title;
 private String cont;
 private Date pdate;
 private boolean isLeaf;
 private int grade;
 public int getId() {
  return id;
 }
 public void setId(int id) {
  this.id = id;
 }
 public int getPid() {
  return pid;
 }
 public void setPid(int pid) {
  this.pid = pid;
 }
 public int getRootId() {
  return rootId;
 }
 public void setRootId(int rootId) {
  this.rootId = rootId;
 }
 public String getTitle() {
  return title;
 }
 public void setTitle(String title) {
  this.title = title;
 }
 public String getCont() {
  return cont;
 }
 public void setCont(String cont) {
  this.cont = cont;
 }
 public Date getPdate() {
  return pdate;
 }
 public void setPdate(Date pdate) {
  this.pdate = pdate;
 }
 public boolean isLeaf() {
  return isLeaf;
 }
 public void setLeaf(boolean isLeaf) {
  this.isLeaf = isLeaf;
 }
 public int getGrade() {
  return grade;
 }
 public void setGrade(int grade) {
  this.grade = grade;
 }
 
 public void initFromRs(ResultSet rs){
  try {
   setId(rs.getInt("id"));
   setPid(rs.getInt("pid"));
   setRootId(rs.getInt("rootid"));
   setTitle(rs.getString("title"));
   setLeaf(rs.getInt("isleaf") == 0 ? true : false);
   setPdate(rs.getTimestamp("pdate"));
   setCont(rs.getString("cont"));
   setGrade(0);
  } catch (SQLException e) {
   e.printStackTrace();
  }
  
 }
}

分页article.jsp：

<%@ page pageEncoding ="GB18030"%>
<%@ page import="java.sql.*,com.bjsxt.bbs.*,java.util.*,java.io.*"%>

 

<%
 //把每页的条目设置为4
 final int PAGE_SIZE = 4 ;
 int totalPages = 0;
 String strPageNo = request.getParameter("pageNo");
 int pageNo = 1;
 if(strPageNo != null && !strPageNo.trim().equals("")){
  try{
   pageNo = Integer.parseInt(strPageNo);
  } catch(NumberFormatException e) {
   pageNo = 1;
  }
 }
 if(pageNo < 1 ){
  pageNo = 1;
 }
 
 List<Article> articles = new ArrayList<Article>();
 Connection conn = DB.getConn();
 
 Statement totalStmt = DB.createStmt(conn);
 ResultSet rsCount = DB.executeQuery(totalStmt,"select count(*) from article where pid = 0");
 rsCount.next();
 int totalRecords = rsCount.getInt(1);
 
 totalPages = (totalRecords + PAGE_SIZE -1)/PAGE_SIZE;
 if(pageNo > totalPages) {
  pageNo = totalPages;
 }
 
 Statement stmt = DB.createStmt(conn);
 int startPages =(pageNo -1 ) * PAGE_SIZE;
 String sql = "select * from article where pid = 0 order by pdate desc limit " + startPages + "," + PAGE_SIZE ;   
 ResultSet rs = DB.executeQuery(stmt,sql);
 while(rs.next()){
  Article a = new Article();
  a.initFromRs(rs);
  articles.add(a);
 }
 
 DB.close(rsCount);
 DB.close(totalStmt);
 DB.close(rs);
 DB.close(stmt);
 DB.close(conn);
%>

<span class="nobreak"> 页:
           第<%=pageNo %>页&nbsp;共<%=totalPages %>页 [ 

           <a href="articleFlat.jsp?pageNo=<%=1%>">第一页</a> |
          <a href="articleFlat.jsp?pageNo=<%=pageNo - 1 %>">上一页</a>
          <a>|</a>
          <a href="articleFlat.jsp?pageNo=<%=pageNo +1 %>">下一页</a>|&nbsp;
          <a href="articleFlat.jsp?pageNo=<%=totalPages %>">最末页</a> ]