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: f8
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CountBean.java fKAG+ t
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/* sL tsvH#
* CountData.java 0$l D
* GVp2|\-L
* Created on 2007年1月1日, 下午4:44 KArnNmJ9
* eESJk14
* To change this template, choose Tools | Options and locate the template under -3c?Yaf"
* the Source Creation and Management node. Right-click the template and choose 5fBW#6N/
* Open. You can then make changes to the template in the Source Editor. 2}Q)&;u
*/ scUWI"
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package com.tot.count; "U&
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/** u]ZCYJ>
* @[S\ FjI
* @author c;bp[Y3R
*/ ~z!U/QR2
public class CountBean { NLC}XL
private String countType; E$rn^keM
int countId; >g6:{-b^a
/** Creates a new instance of CountData */ @4b"0ne}h
public CountBean() {} #sEbu^
public void setCountType(String countTypes){ LE!3'^Zq
this.countType=countTypes; E-irB/0
} I=pTfkTT
public void setCountId(int countIds){ fF8g3|p:
this.countId=countIds; ^YKEc0"w(
} }45&s9m=
public String getCountType(){ ([ xYOxcp5
return countType; W%.Kr-[?`o
} mi3 yiR
public int getCountId(){ fN>o465I6
return countId; avk0pY(n
} [N925?--S
} Zl.}J,0F
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CountCache.java pXCmyLQ
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/* 0*8[m+j1
* CountCache.java :\48=>
* !K1[o'o#
* Created on 2007年1月1日, 下午5:01 #G^?4Za
* 1<
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* To change this template, choose Tools | Options and locate the template under :NO'[iE
* the Source Creation and Management node. Right-click the template and choose dGcG7*EX
* Open. You can then make changes to the template in the Source Editor. ?
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*/ %Sfew/"R0
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package com.tot.count; h4S,(*V$!
import java.util.*; qV.*sdS>
/** +X0?bVT
* Jpws1~
* @author sL
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*/ 4jj@"*^a
public class CountCache { xO6)lVd
public static LinkedList list=new LinkedList();
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/** Creates a new instance of CountCache */ do%6P^qA
public CountCache() {} =g$%.
public static void add(CountBean cb){ *^Wx=#w$V
if(cb!=null){ 2RidI&?c<
list.add(cb); {(AYs*5
} sUcx;<|BC
} -D0kp~AO4N
} *<zfe.
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CountControl.java zVYX#- nv
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/* AY{caM
* CountThread.java sV'(y>PP%
* ;+`t[ go
* Created on 2007年1月1日, 下午4:57 z'JtH^^Z
* kA{[k
* To change this template, choose Tools | Options and locate the template under $+)SW{7
* the Source Creation and Management node. Right-click the template and choose [F/>pL5U$
* Open. You can then make changes to the template in the Source Editor. gEMxK2MNXj
*/ u)MdFz
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package com.tot.count; -S
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import tot.db.DBUtils; P|_>M SO1'
import java.sql.*; } O8|_d
/** [ K;3Qf)
* nWfOiw-t
* @author J"L+`i
*/ yNP
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public class CountControl{ Z~ VOO7|m
private static long lastExecuteTime=0;//上次更新时间 3@*J=LGhKc
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ^i2W=A'P
/** Creates a new instance of CountThread */ *pCT34'--
public CountControl() {} J84Q|E
public synchronized void executeUpdate(){ %%}U
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Connection conn=null; lO9ML-8C1
PreparedStatement ps=null; 5\V>Sj(
try{ (hS
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conn = DBUtils.getConnection(); Tf)qd\
conn.setAutoCommit(false); 9sifc<za
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); "m.j cKt
for(int i=0;i<CountCache.list.size();i++){ iVLfAN @
CountBean cb=(CountBean)CountCache.list.getFirst(); 0~Z>}(
CountCache.list.removeFirst(); &p%0cjg"Q
ps.setInt(1, cb.getCountId()); yf*^Y74
ps.executeUpdate();⑴ hW6og)x
//ps.addBatch();⑵ ,8nu%zcVn
} |?hNl2m
//int [] counts = ps.executeBatch();⑶ F$7>q'#
conn.commit(); i<l_z&
}catch(Exception e){ K2<"O qp_W
e.printStackTrace(); 7,ysixY
} finally{ V6B`q;lA
try{ j]#qq]c
if(ps!=null) { qI"Xh"
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ps.clearParameters(); bf|s=,D
ps.close(); 85+'9#~!
ps=null; X]d;x/2
} :a
@_GIC
}catch(SQLException e){} >
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DBUtils.closeConnection(conn); sa$CCQ
} lk]q\yO_%
} eW,{E)x:
public long getLast(){ HjAhz
return lastExecuteTime; O%L]*vIr
} VAX@'iZr
public void run(){ w{l}(:xPp
long now = System.currentTimeMillis(); +sq'\Tbp
if ((now - lastExecuteTime) > executeSep) { vg[A/$gLM
//System.out.print("lastExecuteTime:"+lastExecuteTime); Zvz Zs
//System.out.print(" now:"+now+"\n"); Jw3VWc
]]
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); UKV0xl
lastExecuteTime=now; m r"b/oM{
executeUpdate(); Z:9xf:g*
} o{7wPwQ;*
else{ ],#Xa.r
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Y S/x;
} jD1/`g%
} ;c p*]
} ^3"~
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//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 /k8Lu+OJ
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类写好了,下面是在JSP中如下调用。 g<pr(7jO
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<% [qbZp1s|(
CountBean cb=new CountBean(); sG{f xha
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); '/8{Mx+
CountCache.add(cb); SO @d\H
out.print(CountCache.list.size()+"<br>"); @h7)M:l
CountControl c=new CountControl(); qF'lh
c.run(); oGt,^!V1
out.print(CountCache.list.size()+"<br>"); LtIp,2GP&_
%>