有时要为每一篇文章统计其点击次数,如果每一次浏览都要更新一次库的话,那性能在访问量很大的情况下,服务器的压力就会很大了,比较好一点的方法就是先将要更新的数据缓存起来,然后每隔一段时间再利用数据库的批量处理,批量更新库。

那么下面本JSP教程提供源码如下:
- CountBean.java
 - /*
 - * CountData.java
 - *
 - * Created on 2009年6月30日, 下午4:44
 - *
 - * To change this template, choose Tools | Options and locate the template under
 - * the Source Creation and Management node. Right-click the template and choose
 - * Open. You can then make changes to the template in the Source Editor.
 - */
 - package com.tot.count;
 - /**
 - *
 - *
 - */
 - public class CountBean {
 - private String countType;
 - int countId;
 - /** Creates a new instance of CountData */
 - public CountBean() {}
 - public void setCountType(String countTypes){
 - this.countType=countTypes;
 - }
 - public void setCountId(int countIds){
 - this.countId=countIds;
 - }
 - public String getCountType(){
 - return countType;
 - }
 - public int getCountId(){
 - return countId;
 - }
 - }
 - CountCache.java
 - /*
 - * CountCache.java
 - *
 - * Created on 2009年6月30日, 下午5:01
 - *
 - * To change this template, choose Tools | Options and locate the template under
 - * the Source Creation and Management node. Right-click the template and choose
 - * Open. You can then make changes to the template in the Source Editor.
 - */
 - package com.tot.count;
 - import java.util.*;
 - /**
 - *
 - * @author http://www.tot.name
 - */
 - public class CountCache {
 - public static LinkedList list=new LinkedList();
 - /** Creates a new instance of CountCache */
 - public CountCache() {}
 - public static void add(CountBean cb){
 - if(cb!=null){
 - list.add(cb);
 - }
 - }
 - }
 - CountControl.java
 - /*
 - * CountThread.java
 - *
 - * Created on 2009年6月30日, 下午4:57
 - *
 - * To change this template, choose Tools | Options and locate the template under
 - * the Source Creation and Management node. Right-click the template and choose
 - * Open. You can then make changes to the template in the Source Editor.
 - */
 - package com.tot.count;
 - import tot.db.DBUtils;
 - import java.sql.*;
 - /**
 - *
 - * @author http://www.tot.name
 - */
 - public class CountControl{
 - private static long lastExecuteTime=0;//上次更新时间
 - private static long executeSep=60000;//定义更新间隔时间,单位毫秒
 - /** Creates a new instance of CountThread */
 - public CountControl() {}
 - public synchronized void executeUpdate(){
 - Connection conn=null;
 - PreparedStatement ps=null;
 - try{
 - conn = DBUtils.getConnection();
 - conn.setAutoCommit(false);
 - ps=conn.prepareStatement("update t_news set hitshits=hits+1 where id=?");
 - for(int i=0;i﹤CountCache.list.size();i++){
 - CountBean cb=(CountBean)CountCache.list.getFirst();
 - CountCache.list.removeFirst();
 - ps.setInt(1, cb.getCountId());
 - ps.executeUpdate();⑴
 - //ps.addBatch();⑵
 - }
 - //int [] counts = ps.executeBatch();⑶
 - conn.commit();
 - }catch(Exception e){
 - e.printStackTrace();
 - } finally{
 - try{
 - if(ps!=null) {
 - ps.clearParameters();
 - ps.close();
 - ps=null;
 - }
 - }catch(SQLException e){}
 - DBUtils.closeConnection(conn);
 - }
 - }
 - public long getLast(){
 - return lastExecuteTime;
 - }
 - public void run(){
 - long now = System.currentTimeMillis();
 - if ((now - lastExecuteTime) ﹥ executeSep) {
 - //System.out.print("lastExecuteTime:"+lastExecuteTime);
 - //System.out.print(" now:"+now+"\n");
 - // System.out.print(" sep="+(now - lastExecuteTime)+"\n");
 - lastExecuteTime=now;
 - executeUpdate();
 - }
 - else{
 - //System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n");
 - }
 - }
 - }
 - //注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释
 - 类写好了,下面是在JSP中如下调用。
 - ﹤%
 - CountBean cb=new CountBean();
 - cb.setCountId(Integer.parseInt(request.getParameter("cid")));
 - CountCache.add(cb);
 - out.print(CountCache.list.size()+"﹤br﹥");
 - CountControl c=new CountControl();
 - c.run();
 - out.print(CountCache.list.size()+"﹤br﹥");
 - %﹥
 
以上就是本JSP教程为你提供的解决高访问量下的服务器压力问题,希望对你有帮助。
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