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: .{;RJ:O
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CountBean.java (Y&gse1}!
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/* IwbV+mWQ
* CountData.java Vfq-H /+
* 3M[d6@a
* Created on 2007年1月1日, 下午4:44 SJ8
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* {KTZSs $n
* To change this template, choose Tools | Options and locate the template under hQzT
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* the Source Creation and Management node. Right-click the template and choose o4rf[.z
* Open. You can then make changes to the template in the Source Editor. bTYR=^9
*/ g rQ,J
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package com.tot.count; J+Y?'"r
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/** #cD$
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* )cOBP}j+
* @author ]U4C2}u
*/ :[_k .1-+
public class CountBean { f0g_Gn $
private String countType; <[gN4x>'
int countId; 8&x&Ou$("V
/** Creates a new instance of CountData */ /^~)iTwH
public CountBean() {}
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public void setCountType(String countTypes){ 44^jE{,9
this.countType=countTypes; ] : ](xW%
} !YM:?%B
public void setCountId(int countIds){ n%vmo
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this.countId=countIds; "0>AefFd#
} |U~\;m@
public String getCountType(){ &u2m6 r>W
return countType; r5lPO*?Df
} Fkqw#s(T
public int getCountId(){ Aba%QQQ
return countId; z+_d* \
} |F=.NY
} \H PB{
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CountCache.java D#>d+X$
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/* HXB&
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* CountCache.java nob}}w]~C
* {*F8'6YQ$
* Created on 2007年1月1日, 下午5:01 >#;>6q9_
* ` apCu
* To change this template, choose Tools | Options and locate the template under i|!R*"
* the Source Creation and Management node. Right-click the template and choose w0.;86<MV
* Open. You can then make changes to the template in the Source Editor. y]k{u\2A
*/ '2p,0Bk9i
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package com.tot.count; ? a*yK8S
import java.util.*; @C~gU@F
/** +=kz".$
* 2-#&ktM%V
* @author b u/GaE~
*/ )Ee`11
public class CountCache { =@;\9j
public static LinkedList list=new LinkedList(); @# p{,L
/** Creates a new instance of CountCache */ c5eimA%`
public CountCache() {} Fe 78YDx?
public static void add(CountBean cb){ uH} }z !
if(cb!=null){ c`)[-
list.add(cb); k#5Qwxu`
} &x[V<Gq
} :{#w-oC>6P
} a0wpsl
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CountControl.java jpiBHi]5+
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/* FbD9G6h5
* CountThread.java lxLEYDGFS
* R{Me~L?
* Created on 2007年1月1日, 下午4:57 ML1/1GK*i+
* R8,
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* To change this template, choose Tools | Options and locate the template under cEPqcy
*
* the Source Creation and Management node. Right-click the template and choose 2B=BRVtSs
* Open. You can then make changes to the template in the Source Editor. pc](
*/ 1|7tq
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package com.tot.count; k`0m|<$
import tot.db.DBUtils; Q,>]f@m
import java.sql.*; {@X)=.Zf
/** _s0;mvz'
* X_wPuU%
* @author 6oR5q 4
*/ p<(b^{EX
public class CountControl{ JjH141 n%D
private static long lastExecuteTime=0;//上次更新时间 &UX:KW`=
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 \2 `|eo
/** Creates a new instance of CountThread */ HUGhz
public CountControl() {} " ,45p@
public synchronized void executeUpdate(){ Up1e4mNL
Connection conn=null; /V>yF&p
PreparedStatement ps=null; `+T"^{
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try{ IKeO&]k
conn = DBUtils.getConnection(); f2M}N
conn.setAutoCommit(false); 6"c(5#H
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); WP?AQD
for(int i=0;i<CountCache.list.size();i++){ 1n>(CwLG"
CountBean cb=(CountBean)CountCache.list.getFirst(); SOJkeN
CountCache.list.removeFirst(); mA\}zLw+r9
ps.setInt(1, cb.getCountId()); C.=[K_
ps.executeUpdate();⑴ pb|,rLNZ
//ps.addBatch();⑵ /E5>cqX4A
} 6Iv &c2
//int [] counts = ps.executeBatch();⑶ 1>_2 =^[
conn.commit(); qL!pDZk
}catch(Exception e){ 1xb1?/n1#
e.printStackTrace(); X:OUu;
} finally{ N?mQ50o~C
try{ .arWbTR)~U
if(ps!=null) { GsNZr=;C
ps.clearParameters(); .vtV2lq
ps.close(); Uf\U~wM<
ps=null; $xq$
} nW_cjYS%
}catch(SQLException e){} \2y[Hy?
DBUtils.closeConnection(conn); LVBE+{P\5?
} )SWLX\b
} }Gh95HwE
public long getLast(){ 3|1v)E
return lastExecuteTime; "|d# +C
} 2$yNryd
public void run(){ LCemM; o
long now = System.currentTimeMillis(); L-Pq/x2r
if ((now - lastExecuteTime) > executeSep) { t'bhA20Z\
//System.out.print("lastExecuteTime:"+lastExecuteTime); ~>>^7oq
//System.out.print(" now:"+now+"\n"); uwWKsZ4:ij
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); \ H!Klp
lastExecuteTime=now; `:YCOF
executeUpdate(); g3vR\?c`
} l
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else{ Z3z"c
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); [ih^VlZ
} C;XhnqWv+l
} 4)E$. F^
} g,}_&+q:.M
//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 }\aJ%9X02
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类写好了,下面是在JSP中如下调用。 .%+y_.l
Q?{^8?7
<% o%[swoM@
CountBean cb=new CountBean(); Zd8`95
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); u\o~'Jz
CountCache.add(cb); {Z^q?~zC[
out.print(CountCache.list.size()+"<br>"); e#z#bz2<
CountControl c=new CountControl(); $'93:9tg
c.run(); F0/!+ho
out.print(CountCache.list.size()+"<br>"); T3h 1eU
%>