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: FfRvi8
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CountBean.java @?n~v^
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/* {i<L<Y(3
* CountData.java |4C5;"P c
* <YM!K8hu$
* Created on 2007年1月1日, 下午4:44 P<CPA7K
* 2RU/oqmR
* To change this template, choose Tools | Options and locate the template under 3,"G!0 y.
* the Source Creation and Management node. Right-click the template and choose )%JjV(:
* Open. You can then make changes to the template in the Source Editor. HIqe~Vc
*/ fKbg ?
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package com.tot.count; a9uMgx}
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/** /EW=OZ/
* *DgRF/S
* @author A I v
*/ g8R@ol0
public class CountBean { 8 \"A-+_Q
private String countType; I]z4}#+cX
int countId; \"a~~Koe
/** Creates a new instance of CountData */ B)x^S
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public CountBean() {} e +Ikw1y"f
public void setCountType(String countTypes){ !lL~#l:F
this.countType=countTypes; +ovT?CMo
} R('\i/fy
public void setCountId(int countIds){ e>UU/Ks
this.countId=countIds; ~}_S]^br
} Sa-" G`
public String getCountType(){ ?>1wZ
return countType; i'B$Xr
} #z61I"kU
public int getCountId(){ 2U`!0~pod
return countId; v'Pbx
} Nh01NY;
} rMoz+{1A
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CountCache.java *m8{yh
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/* SN 4JX
* CountCache.java -C2[ZP-
* +V9 (4la
* Created on 2007年1月1日, 下午5:01 zWrynJ}s
* L0R$T=~%)
* To change this template, choose Tools | Options and locate the template under uf1s}/M
* the Source Creation and Management node. Right-click the template and choose mT>RQ.
* Open. You can then make changes to the template in the Source Editor. -;O"Y?ME
*/ OYfRtfE
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package com.tot.count; u}?|d8$h\
import java.util.*; IC6'>2'=T
/** ;*{Ls#
* eF(oHn,
* @author NE><(02qW
*/ *Oq&g\K)
public class CountCache { F;MACu;x
public static LinkedList list=new LinkedList(); kZ0z]Y
/** Creates a new instance of CountCache */ ,ZZ5A;)
public CountCache() {} h05BZrE
public static void add(CountBean cb){ f.c2AY~5[
if(cb!=null){ B@ >t$jK
list.add(cb); A>frf[fAW
} *|^||
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} U1D;O}z~
} Z-L }"~
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CountControl.java ,=[r6k<
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/* l>6p')F!
* CountThread.java /vPr^Wv
* ,uD}1
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* Created on 2007年1月1日, 下午4:57 It]GlxMX
* (_Th4'(@Y
* To change this template, choose Tools | Options and locate the template under M}`T-"qf
* the Source Creation and Management node. Right-click the template and choose I0N~>SpZ5
* Open. You can then make changes to the template in the Source Editor. ]l"9B'XR
*/ SB:z[kfz|
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package com.tot.count; " eS-i@
import tot.db.DBUtils; (/S6b
import java.sql.*; 9RC:-d;;_
/** {]iM5?
* zj$Ve
* @author I/zI\PP,
*/ ~lbm^S}-
public class CountControl{ R ^"*ut
private static long lastExecuteTime=0;//上次更新时间 sRQ4pnnrn
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Xif>ZL?aXb
/** Creates a new instance of CountThread */ ([ A%>u>h
public CountControl() {} Y pvFv-
public synchronized void executeUpdate(){ /PpZ6ne~[
Connection conn=null; >ktekO:H
PreparedStatement ps=null; 6ZQ$5PY
try{ D 77$aCt
conn = DBUtils.getConnection(); P)[QC
conn.setAutoCommit(false); WHr:M/qD
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); v?o("I[ C
for(int i=0;i<CountCache.list.size();i++){ ;+n25_9
CountBean cb=(CountBean)CountCache.list.getFirst(); S-79uo
CountCache.list.removeFirst(); (\4YBaGd
ps.setInt(1, cb.getCountId()); \*#E4`Y
ps.executeUpdate();⑴ ]{AHKyA{:
//ps.addBatch();⑵ ~7H?tp.Dw
} T^g i^{
//int [] counts = ps.executeBatch();⑶
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conn.commit(); 0L\vi
}catch(Exception e){ p+;x&h)[l
e.printStackTrace(); b(A;mt#N
} finally{ ^oEaE#I
try{ ~g *`E!2
if(ps!=null) { ~Q)Dcit-
ps.clearParameters(); 0{u#{_
ps.close(); BQ{'r^u
ps=null; R4XcWx*pQ
} xw3A |Aj?r
}catch(SQLException e){} XeozRfk%J|
DBUtils.closeConnection(conn); 787}s`,}
} { /Gm|*e{
} W|6.gN]
public long getLast(){ GFZx[*+%%z
return lastExecuteTime; bQwiJ`B&
} \V*E:_w*
public void run(){ mnH1-}oL
long now = System.currentTimeMillis(); :Ek3]`q#
if ((now - lastExecuteTime) > executeSep) { 'D?sRbJ=
//System.out.print("lastExecuteTime:"+lastExecuteTime); 2'WdH1UrBc
//System.out.print(" now:"+now+"\n"); )J&!>GP
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); {#l@9r%
lastExecuteTime=now; ?Q6ZZQ~
executeUpdate(); ;{rl
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} >H?~2O
else{ tmC9p6%
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); &uJ7[m19z
} S4%MnT6Uy
} )Ju$PrO
} e0<L^|S
//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 leEzfbb{'.
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类写好了,下面是在JSP中如下调用。 [~ |e:
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<% q?oJ=]m"
CountBean cb=new CountBean(); 7
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); !B&1{
CountCache.add(cb); G/8G`teAZ
out.print(CountCache.list.size()+"<br>"); V__n9L/t
CountControl c=new CountControl(); |y2cI,&
c.run(); !n5s/"'H
out.print(CountCache.list.size()+"<br>"); wq3 V&@.
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