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: 4X^{aIlshk
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CountBean.java (K>=!&tlp=
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/* 7vf?#^RlV
* CountData.java b}OOG
* ~BJ~]~0P`
* Created on 2007年1月1日, 下午4:44 ['l.]k-b}
* Uq8=R)1<|d
* To change this template, choose Tools | Options and locate the template under @T6Z3Zj}
* the Source Creation and Management node. Right-click the template and choose G>q16nS~KP
* Open. You can then make changes to the template in the Source Editor. 5HAIKc
*/ Q|+g= |%^
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package com.tot.count; q%Fc?d9
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/** y?1<7>L5~
* QxjX:O
* @author _=\=oC
*/ /e0cx:.w
public class CountBean { qauZ-Qoc9
private String countType; QaMB=wVr
int countId; /V%]lmxQ
/** Creates a new instance of CountData */ {g7[3WRy
public CountBean() {} D]UqM<0Rz
public void setCountType(String countTypes){ dU4G!
this.countType=countTypes; D" 4*&
} %^C.e*
public void setCountId(int countIds){ 0D*uZ,oBEw
this.countId=countIds; S
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} +uY)MExs2
public String getCountType(){ er[%Nt+99
return countType; %488"
} k'd(H5A
public int getCountId(){ J^G#x}y
return countId; 4[eQ5$CB<u
} nvdo|5
} w|uO)/v
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CountCache.java W"@FRWcd
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/* E9yBa=#*c
* CountCache.java 3Q@HP;<
* Q6|~ks+Y
* Created on 2007年1月1日, 下午5:01 NQD*8PGfj
* Po:)b
* To change this template, choose Tools | Options and locate the template under BRx`83CK
* the Source Creation and Management node. Right-click the template and choose Jf,)Y>EI
* Open. You can then make changes to the template in the Source Editor. bBFdr
*/ T|c9Swur
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package com.tot.count; 0{O|o_
import java.util.*; y<<:6OBj
/** H$/r{gfg^
* h]#wwJF
* @author +gQn,HX
*/ =eXJZPR
public class CountCache { ( _{\tgSm
public static LinkedList list=new LinkedList(); r95l.v
/** Creates a new instance of CountCache */ "^~>aVuXf
public CountCache() {} 7D;g\{>M
public static void add(CountBean cb){ j3W)5ZX
if(cb!=null){ E!eBQ[@
list.add(cb);
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} #jja#PF]7
} O-M4NKl]6
} \(C_t1
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CountControl.java p$5+^x'(
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/* K`9ph"(Z
* CountThread.java oM@X)6P_
* _l`s}yC
* Created on 2007年1月1日, 下午4:57 !*?Ss
* "o*zZ;>^
* To change this template, choose Tools | Options and locate the template under 3KF[ v{
* the Source Creation and Management node. Right-click the template and choose k]n=7vw;
* Open. You can then make changes to the template in the Source Editor. +;}XWV
*/ f8Xe%"<
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package com.tot.count; @CSTp6{y
import tot.db.DBUtils; #NAlje( 7
import java.sql.*; 95,{40;X7
/** *Q<%(JJ
* |$r|DX1[
* @author ;btH[a iV
*/ &DMKZMj<Q*
public class CountControl{ v;9VX
private static long lastExecuteTime=0;//上次更新时间 31n5n
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 S=^a''bg
/** Creates a new instance of CountThread */ S)@95pb
public CountControl() {} M.Fu>Xi
public synchronized void executeUpdate(){ ?Afx{H7
Connection conn=null; :>Gm&w
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PreparedStatement ps=null; ?s<'3I{F`
try{ dnby &-+T
conn = DBUtils.getConnection(); g2=5IU<
conn.setAutoCommit(false); LDJ=<c!
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); fR>(b?C
for(int i=0;i<CountCache.list.size();i++){ ldJ:A*/M6
CountBean cb=(CountBean)CountCache.list.getFirst(); E47U &xL
CountCache.list.removeFirst(); Q1G?e,Q
ps.setInt(1, cb.getCountId()); He4sP`&I
ps.executeUpdate();⑴ uLw$`ihw
//ps.addBatch();⑵ n=vW oU9
} *{]9e\DF
//int [] counts = ps.executeBatch();⑶ QY,.|
conn.commit(); V}#2pP
}catch(Exception e){ H4HWr6
e.printStackTrace(); vG'JMzAm
} finally{ Vo%MG.IPB
try{ W9{>.E?
if(ps!=null) { F<y5zqGy@
ps.clearParameters(); ELp @/c=Wr
ps.close(); 2WjQ-mM#
ps=null; xGQ958@
} eCYgi7?
}catch(SQLException e){} ^X%{]b K
DBUtils.closeConnection(conn); [~;#]az
} )fz)Rrr
} SC~cryb
public long getLast(){ zMT0ToG
return lastExecuteTime; 1;p'2-x
} 0u4:=Z}W
public void run(){ $ 1 N_qu
long now = System.currentTimeMillis(); Hnwir!=7
if ((now - lastExecuteTime) > executeSep) { %y~=+Sm%m
//System.out.print("lastExecuteTime:"+lastExecuteTime); Kq|L:Z
//System.out.print(" now:"+now+"\n"); GM6Y`iU
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); a*d>WN.;U
lastExecuteTime=now; &v+8RY^F=
executeUpdate(); eu(1bAfS&T
} $=f,z>j
else{ 5$Yt@8;
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Aw)='&;^z
} R$@|t?
} X[:&p|g]
} $cri"G
//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 }>cQ}6n.
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类写好了,下面是在JSP中如下调用。 K9FtFd
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<% gqaENU>
CountBean cb=new CountBean(); P`HE3?r
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); )o'&f"/
CountCache.add(cb); dZ&/Iz
out.print(CountCache.list.size()+"<br>"); odPq<'V|AY
CountControl c=new CountControl(); [-cYFdt"V
c.run(); +*3\C!
out.print(CountCache.list.size()+"<br>"); BzL>,um
%>