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: /YH`4e5g
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CountBean.java O'$K],=BS
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/* 88lxHoPV
* CountData.java }gGkV]
* X}cZxlqc
* Created on 2007年1月1日, 下午4:44 hat>kXm2K
* 1ibnx2^YB
* To change this template, choose Tools | Options and locate the template under ,*Z.
* the Source Creation and Management node. Right-click the template and choose HjA_g0u
* Open. You can then make changes to the template in the Source Editor. p'f%%#I
*/ ys'T~Cs
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package com.tot.count; v,OpTu:1
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/** --fFpM3EvS
* &(blN.2
* @author bMKL1+y(
*/ QI}E4-s8
public class CountBean { >&S0#>wmyG
private String countType; ~AZWds(,N
int countId; z;Q<F
/** Creates a new instance of CountData */ 2i7e#
public CountBean() {} 8)yI<`q6
public void setCountType(String countTypes){ 5$rSEVg9
this.countType=countTypes; kKiA
} L]d-33.c!H
public void setCountId(int countIds){ R Oc`BH=
this.countId=countIds; [/ M`
} cz/Q/%j$/
public String getCountType(){ z[EFQ^*>
return countType; jrMe G.e=D
} :+rUBYWx
public int getCountId(){ O+~ 7l?o
return countId; 'ZP)cI:+X
} =ll=)"O
} EU-]sTJLF
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CountCache.java $`VFdAe
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/* ]N{0:Va@D
* CountCache.java o0It82?RN
* ^tH#YlV4>9
* Created on 2007年1月1日, 下午5:01 ]J7Qgp)i
* b)#Oc,
* To change this template, choose Tools | Options and locate the template under ;GGK`V
* the Source Creation and Management node. Right-click the template and choose ^U[D4UM
* Open. You can then make changes to the template in the Source Editor. :dI\z]Y(
*/ MXD4|r(
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package com.tot.count; k1
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import java.util.*; t*XN_=E$f
/** FFKGd/:!
* PVOx`<ng
* @author 3)=c]@N0
*/ u3 0s_\
public class CountCache { 28.~iw
public static LinkedList list=new LinkedList(); xiblPF_n3
/** Creates a new instance of CountCache */ .TJEUK
public CountCache() {} : 9t4s#.
public static void add(CountBean cb){ 2&!bfq![
if(cb!=null){ .L6Zm U
list.add(cb); .;7> y7$*
} -O!/Jv"{,[
} rN)V[5R#M
} {a(&J6$VE
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CountControl.java Dnf*7)X
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/* =
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* CountThread.java }J:+{4Yn
* Hu3wdq
* Created on 2007年1月1日, 下午4:57 *hLQ
* NB_)ZEmF
* To change this template, choose Tools | Options and locate the template under "es?=
* the Source Creation and Management node. Right-click the template and choose 7R4z}2F2
* Open. You can then make changes to the template in the Source Editor. mEyK1h1G@
*/ Gq<X4C#|
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package com.tot.count; :#~U<C@o
import tot.db.DBUtils; KJ2Pb"s
import java.sql.*; &fa5laJb
/** 7CXW#H
* !~]<$WZV
* @author }Ew hj>w
*/ |*/[`|*G
public class CountControl{ 3DgsI7-F
private static long lastExecuteTime=0;//上次更新时间 WYB{% yf
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Isy'{-H
/** Creates a new instance of CountThread */ 7{@l%jx][
public CountControl() {} XW{>-PBg:
public synchronized void executeUpdate(){ 0& >H^
Connection conn=null; Q6gt+FKU9
PreparedStatement ps=null; 1923N]b
try{ Y6i _!z[V[
conn = DBUtils.getConnection(); G;NF5`*4mc
conn.setAutoCommit(false); dovZ#D@Q
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); gKLyL]kAGz
for(int i=0;i<CountCache.list.size();i++){ @Jm7^;9/
CountBean cb=(CountBean)CountCache.list.getFirst(); )a@k]#)Skm
CountCache.list.removeFirst(); 5tjP6Z`!9`
ps.setInt(1, cb.getCountId()); 9,j-Vp!G
ps.executeUpdate();⑴ 8to8!(
//ps.addBatch();⑵ hpTDxh'?$C
} :cu#V
//int [] counts = ps.executeBatch();⑶ $$b
9&mTl#
conn.commit(); 'r1LSht'
}catch(Exception e){ !`1'2BC
e.printStackTrace(); zDhB{3-Q1{
} finally{ I&n
try{ _Z5Mw+=19
if(ps!=null) { \`V;z~@iA
ps.clearParameters(); #mize
ps.close(); {7 TlN.(
ps=null; -7J| l
} 2(5ebe[
}catch(SQLException e){} qTZFPfyU
DBUtils.closeConnection(conn); n
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} su*Pk|6%
} m]i @ +C
public long getLast(){ kmzH'wktt
return lastExecuteTime; 6T 8!xyi-+
} DCqY|4Qc
public void run(){ .ERO|$fv
long now = System.currentTimeMillis(); F}Vr:~
if ((now - lastExecuteTime) > executeSep) { `Al;vVMRO
//System.out.print("lastExecuteTime:"+lastExecuteTime); ctE\ q
//System.out.print(" now:"+now+"\n"); ()&~@1U
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); wtje(z5IL
lastExecuteTime=now; Eu"_MgD
executeUpdate(); gbVdOm
} pTIf@n6I
else{ )95f*wte
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); p<=$&*
} W9NX=gE4
} *CHI2MB
} rE@T79"
//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 =zQN[
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类写好了,下面是在JSP中如下调用。 Ft}@1w5
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<% #o1=:PQaC
CountBean cb=new CountBean(); :
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); RKPO#qju\F
CountCache.add(cb); n:MdYA5,m
out.print(CountCache.list.size()+"<br>"); 6@DF
CountControl c=new CountControl(); /Q,mJ.CnSR
c.run(); J:V?EE,\-
out.print(CountCache.list.size()+"<br>"); Sa2>`":d
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