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: p{W
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CountBean.java +;,J0,Yn
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/* t?)]xS)
* CountData.java
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* ]3,
* Created on 2007年1月1日, 下午4:44 DO-M0L
* ?E
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* To change this template, choose Tools | Options and locate the template under @lWNSf
* the Source Creation and Management node. Right-click the template and choose $IX(a4'
* Open. You can then make changes to the template in the Source Editor. ub9[!}r't
*/ 4q7H
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package com.tot.count; Ja4M@z
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/** }` H{;A
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* NS`hXf
* @author Bw!J!cCj
*/ z;e@m2.IM
public class CountBean { :@P6ibcX
private String countType; cZF|oZ6<
int countId; QGV#AID3XW
/** Creates a new instance of CountData */ Xf#;`*5
public CountBean() {} :E|Jqi \
public void setCountType(String countTypes){ "nfi:A1
this.countType=countTypes; ,X:3w3nr^
} x7^VU5w#
public void setCountId(int countIds){ 517wduj
this.countId=countIds; 0<uLQVoR2n
} l59
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public String getCountType(){ m-tn|m!J
return countType; btnD+O66<
} \),f?f-m
public int getCountId(){ u$zRm(!RB
return countId; :=+YZ|&j
} a3w6&e`
} K;rgLj0m
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CountCache.java p^q/u
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/* 2ib,33 Z
* CountCache.java &s}sA+w
* WHOy\j},V
* Created on 2007年1月1日, 下午5:01 8jL^q;R_(
* P*K"0[\n
* To change this template, choose Tools | Options and locate the template under AY<L8
* the Source Creation and Management node. Right-click the template and choose *,:2O&P
* Open. You can then make changes to the template in the Source Editor. RFFbS{U*
*/ 5[B)U">]
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package com.tot.count; OvwoU=u
import java.util.*; "K9[P:nw
/** Wf5;~RJC?
* 8mRZ(B>% X
* @author oHv.EO
*/ :eD-'#@$u
public class CountCache { /4+Q;
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public static LinkedList list=new LinkedList(); na9YlJ\
/** Creates a new instance of CountCache */ \<xo`2b
public CountCache() {} )16+Pm8
public static void add(CountBean cb){ 5Uy*^C7M^
if(cb!=null){ UY({[?Se
list.add(cb); LY)Wwl*wc
}
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} J@<f*
} %(6+{'j~#
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CountControl.java p$x>I3C(\
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/* Ah@e9`_r
* CountThread.java [Y.JC'F#
* g$"x,:2x{
* Created on 2007年1月1日, 下午4:57 ujBm"p_|
* F !OD*]
* To change this template, choose Tools | Options and locate the template under `^on`"\{u
* the Source Creation and Management node. Right-click the template and choose :6)!#q'g
* Open. You can then make changes to the template in the Source Editor. \nuzl
*/ 3_boEYl0
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package com.tot.count; JBOU$A~
import tot.db.DBUtils; Lk$Mfm5"M
import java.sql.*; /g9^g(
/** R)$]r>YZF
* <Z_\2
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* @author ;@gI*i
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*/ cL.>e=x$
public class CountControl{ v^Fu/Y
private static long lastExecuteTime=0;//上次更新时间 62.Cq!~
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 G.@K#a9
/** Creates a new instance of CountThread */ -6s]7#IC
public CountControl() {} @gf <%>
public synchronized void executeUpdate(){ ;g+fY6
Connection conn=null; '-I\G6w9
PreparedStatement ps=null; tBZ?UAe;
try{ lFIaC}
conn = DBUtils.getConnection(); =HIKn6C<
conn.setAutoCommit(false); K%/\XnCY
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); gN(kRhp
for(int i=0;i<CountCache.list.size();i++){ F g):>];<9
CountBean cb=(CountBean)CountCache.list.getFirst(); N.]~%)K:{
CountCache.list.removeFirst(); Yc~l Yz+b
ps.setInt(1, cb.getCountId()); z(O*DwY#
ps.executeUpdate();⑴ ^2%)Nq; O
//ps.addBatch();⑵ 9{S$%D
} }uaFmXy3
//int [] counts = ps.executeBatch();⑶ e?07o!7[;
conn.commit(); .`J*l=u$
}catch(Exception e){ 5\}Y=Pa
e.printStackTrace(); %RF$Y=c'C
} finally{ %z[=T@
try{ 1B&XM^>/
if(ps!=null) { sRcS-Yw[S
ps.clearParameters(); B>d49(jy
ps.close(); yHs9J1Sf
ps=null; ?/hS1yD;
} x#5[i;-c
}catch(SQLException e){} Q;=4']hYU
DBUtils.closeConnection(conn); =x(k)RTDu
} zp'hA
} vfhoN]v
public long getLast(){ glM42s
return lastExecuteTime; <~v4BiQ3l^
} u|"YS-dH
public void run(){ `O.pT{Lf
long now = System.currentTimeMillis(); .),9a,
if ((now - lastExecuteTime) > executeSep) { 'zMmJl}\vd
//System.out.print("lastExecuteTime:"+lastExecuteTime); 'aD"v>
//System.out.print(" now:"+now+"\n"); <j#IR
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); CV{ZoY
lastExecuteTime=now; :U'n0\
executeUpdate(); VB8eGMo
} &\6(iL
else{ QL2LIs
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 9aIv|cS?
} \ E5kpm
} LSXsq}
} |rhB@k
//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 ~WV1t][
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类写好了,下面是在JSP中如下调用。 3w[uc ~f
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<% &lzCRRnvt
CountBean cb=new CountBean(); tN.BI1nB
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ,5t_}d|3C=
CountCache.add(cb); @ZV>Cl@%2
out.print(CountCache.list.size()+"<br>"); - \ew,y
CountControl c=new CountControl(); Qch'C0u
c.run(); m)6-D-&7
out.print(CountCache.list.size()+"<br>"); 0CX9tr2J
%>