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。源码如下: i LAscb
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CountBean.java j=J/x:w_e
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/* !a<ng&H^U
* CountData.java E P+J
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* m6djeOl
* Created on 2007年1月1日, 下午4:44 eY\yE"3
* MS]r:X6
* To change this template, choose Tools | Options and locate the template under q]M0md
* the Source Creation and Management node. Right-click the template and choose ]fD}
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* Open. You can then make changes to the template in the Source Editor. Faf&U%]*`
*/ {GO#.P"
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package com.tot.count; ((I%'
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/** 3 9|MX21k
* 2|bn(QYz
* @author Ow077v?
*/ YDFyX){
public class CountBean { 9I/N4sou
private String countType; +@:x!q|^
int countId; h=%_Ao<x
/** Creates a new instance of CountData */ ,{q;;b9
public CountBean() {} lA-h`rl/
public void setCountType(String countTypes){ Wr5V`sM
this.countType=countTypes; p6WX9\qS(
} S[T8T|_
public void setCountId(int countIds){ xp9pl[l
this.countId=countIds; -Vhw^T1iV
} nJLFfXWx
public String getCountType(){ gGS=cdlV
return countType; Y)a^(!<H<
} [66!bM&
public int getCountId(){ tdaL/rRe
return countId; ,'iE;o{Tu
} _\HQvH
} Z*2Vpnqh\
*
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CountCache.java C{XmVc.
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/* 50C
* CountCache.java V,?yPi$#E
* 13=.H5
* Created on 2007年1月1日, 下午5:01 .k
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* O s.4)
* To change this template, choose Tools | Options and locate the template under XEZF{lP
* the Source Creation and Management node. Right-click the template and choose D{~fDRR
* Open. You can then make changes to the template in the Source Editor. |qZ1|
*/ m7>JJX3=<
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package com.tot.count; [,KXze_m
import java.util.*; ApXy=?fc
/** R n*L
* 78H'ax9m
* @author 1|6%evPu(
*/ @[i4^
public class CountCache { }k
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public static LinkedList list=new LinkedList(); A7hVHxNJ-
/** Creates a new instance of CountCache */ ,$+V
public CountCache() {} a"g!e^
public static void add(CountBean cb){ (41|'eB\\
if(cb!=null){ )M//l1
list.add(cb); Q7COQ2~K
} \<6CZ
} Y.ToIka{
}
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CountControl.java rkY[E(SY
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/* x6ARzH\
* CountThread.java ;Nj7qt
* u21EP[[,
* Created on 2007年1月1日, 下午4:57 do+.aOC
* @w !PaP
* To change this template, choose Tools | Options and locate the template under 9lH?-~9
* the Source Creation and Management node. Right-click the template and choose (<oyN7NT
* Open. You can then make changes to the template in the Source Editor. Ev(>z-{F
*/ EeRX+BM,
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package com.tot.count; t#pS{.I
import tot.db.DBUtils; <=0
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import java.sql.*; X;c'[q
/** 6N
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* xzZ38xIhV
* @author /j|G(vt5
*/ 28J^DMOW
public class CountControl{ Mz~D#6=
private static long lastExecuteTime=0;//上次更新时间 krvp&+uX
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 [>%xd)8.c
/** Creates a new instance of CountThread */ u=7J/!H7^
public CountControl() {} C-MjJ6D<
public synchronized void executeUpdate(){ Pjjewy1}^
Connection conn=null; 5VAK:eB
PreparedStatement ps=null; *P2S6z2
try{ 8tFoN*M
conn = DBUtils.getConnection(); =i*;VFc
conn.setAutoCommit(false); (/j/>9iro
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); s<eb;Z2D
for(int i=0;i<CountCache.list.size();i++){ YLv'43PL
CountBean cb=(CountBean)CountCache.list.getFirst(); K[r^'P5m
CountCache.list.removeFirst(); j<@lX^
ps.setInt(1, cb.getCountId()); 9-DZU,`P
ps.executeUpdate();⑴ nV:LqF=
//ps.addBatch();⑵ $m1z-i;/
} 'JfdV%M
//int [] counts = ps.executeBatch();⑶ >kp?vK;'B
conn.commit(); 9Ujo/3,Ak
}catch(Exception e){ LNpup`>`
e.printStackTrace(); A}N?/{y)G
} finally{ @u]rWVy;\[
try{ kZZh"#W: L
if(ps!=null) { g/+C@_&m
ps.clearParameters(); )~] (&
ps.close(); a8iQ4
ps=null; qHrA%k^!2O
} ,\ k(x>oy
}catch(SQLException e){} ,5,!es@`b
DBUtils.closeConnection(conn); s1NKLt
} U4-g^S[
} G) 7;;
public long getLast(){ dA0.v+Foz"
return lastExecuteTime; `t9?=h!
} EzV96+
public void run(){ v` 7RCg`
long now = System.currentTimeMillis(); fb8g7H|
if ((now - lastExecuteTime) > executeSep) { 7=WT69,&
//System.out.print("lastExecuteTime:"+lastExecuteTime); af+IP_6
.
//System.out.print(" now:"+now+"\n"); #Xb+`'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ^1aAjYFn
lastExecuteTime=now; TXk?#G\o
executeUpdate(); i9A+gtd
} ;\Y&ce
else{ !Kj,9NX{U
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 3]UUG
} ez^@NK
} lM{
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} }36QsH8
//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 A"D,Kg
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类写好了,下面是在JSP中如下调用。 Z1Z1@2 T
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<% K7W6ZH9;
CountBean cb=new CountBean(); "7V2lu
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Jesjtcy<*
CountCache.add(cb); ;R?I4}O#R8
out.print(CountCache.list.size()+"<br>"); J@X'PG<
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CountControl c=new CountControl(); *nsAgGKKM^
c.run(); qt
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out.print(CountCache.list.size()+"<br>"); )>-ibf`#?
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