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: j@Qg0F
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CountBean.java @|a>&~xX
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/* kj+#TnF-
* CountData.java `:'w@(q
* n;R#,!<P
* Created on 2007年1月1日, 下午4:44 pf4 ^Bk}e
* E&Qi@Ty
* To change this template, choose Tools | Options and locate the template under U|G|l|Bl
* the Source Creation and Management node. Right-click the template and choose o;b0m;~
* Open. You can then make changes to the template in the Source Editor. RFh"&0[
*/ )XQ`M?**M
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package com.tot.count; Q4t(@0e}
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/** 6.t',LTB
* PL{Q!QJK'
* @author d2X[(3
*/ 4`#F^2r!
public class CountBean { EL3|u64GO
private String countType; M.h`&8
int countId; .^)UO
/** Creates a new instance of CountData */ Cw5%\K$=
public CountBean() {} z9W`FBg
public void setCountType(String countTypes){ 1GEK:g2B
this.countType=countTypes; "QoQ4r<|
} lq.Te,Y%w
public void setCountId(int countIds){ i?Ss: v^
this.countId=countIds; O7']
} %7Kooq(i
public String getCountType(){ 7z_;t9Y
return countType; \qsw"B*tv`
} UDf9FnG}L
public int getCountId(){ 1Xy]D
return countId; Gf8s?l
} AvR2_
} v+6@cC
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CountCache.java 0;,IKXK6X
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/* wo5ZxM
* CountCache.java GC8}X;((Y
* 5CAR{|a
* Created on 2007年1月1日, 下午5:01 {|9}+
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* Ql?^
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* To change this template, choose Tools | Options and locate the template under o/[
* the Source Creation and Management node. Right-click the template and choose P[t$\FS
* Open. You can then make changes to the template in the Source Editor. #s5 pz8v
*/ l2b{u
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package com.tot.count; %Qn(rA@9
import java.util.*; QGiAW7b5
/** _RMQy~&b
* g.%
* @author mN0=i(H<
*/ OLq
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public class CountCache { ,xJrXPW
public static LinkedList list=new LinkedList(); ^[TV;9I*
/** Creates a new instance of CountCache */ G,&%VQ3P>
public CountCache() {} "$p#&W69"J
public static void add(CountBean cb){ Hv#q:R8
if(cb!=null){ Q/_[--0
list.add(cb); x)5V.q
} Bp AB5=M0
} KB{RU'?f|
} jyW[m,#(go
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CountControl.java }{7e7tW6
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/* jStmS2n
* CountThread.java + R$?2
* 1`r| op},
* Created on 2007年1月1日, 下午4:57 E|Bd>G
* A,i()R'I
* To change this template, choose Tools | Options and locate the template under y93k_iq$S
* the Source Creation and Management node. Right-click the template and choose 1r`i]1<H
* Open. You can then make changes to the template in the Source Editor. fhp)S",
*/ 7u11&(Lz
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package com.tot.count; hsce:TB
import tot.db.DBUtils; irxz l3
import java.sql.*; f|0lj
/** "|LQK0q3
* I/u9RmbU
* @author (*^DN{5
*/ eO5ktEoJ
public class CountControl{ MB$a82bY
private static long lastExecuteTime=0;//上次更新时间 UKB_Yy^Y
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 D(Ix!G/
/** Creates a new instance of CountThread */ `bgb*Yaod
public CountControl() {} T`L}[?w
public synchronized void executeUpdate(){ 3l:XhLOj
Connection conn=null; ~^o=a?L`<
PreparedStatement ps=null; mX_)b>iW
try{ bAhZ7;T~
conn = DBUtils.getConnection(); #a}N"*P
conn.setAutoCommit(false); b;vNq
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); X\2_;zwf
for(int i=0;i<CountCache.list.size();i++){ u*R7zY
CountBean cb=(CountBean)CountCache.list.getFirst(); VyZV(k
CountCache.list.removeFirst(); A!HK~yk~Q
ps.setInt(1, cb.getCountId()); 2;(W-]V?
ps.executeUpdate();⑴ }""p)Y&
//ps.addBatch();⑵ c8Pb
} XL"=vbD
//int [] counts = ps.executeBatch();⑶ S=9E@(]
conn.commit(); pDDG_4E>
}catch(Exception e){ t[O+B6
e.printStackTrace(); K+ehr
} finally{ gRvJ.Q {h
try{ "@t-Cy:!O
if(ps!=null) {
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ps.clearParameters(); y_%&]/%
ps.close(); h;Mu[`
ps=null; "Pdvmur
} m# ad6
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}catch(SQLException e){} zzJ^x8#R
DBUtils.closeConnection(conn); Y?!/>q
} $%}>zqD1
} {CP o<lz
public long getLast(){ 75 Fp[Q-
return lastExecuteTime; -N^=@Yx)
} ' o=E!?
public void run(){ 22bT3
long now = System.currentTimeMillis(); @a;sV!S{
if ((now - lastExecuteTime) > executeSep) { Yk7"XP[Y
//System.out.print("lastExecuteTime:"+lastExecuteTime); twbcuaCTW
//System.out.print(" now:"+now+"\n"); cyc>_$/;1
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); sFx$>:$
lastExecuteTime=now; a-Y6w5
executeUpdate(); w|G~Il
} )kA2vX^=Z
else{ 59MR|Jt
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); cju@W] !
} \]a uSO
} PJwEA
} .HD ebi
//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 1Zq
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类写好了,下面是在JSP中如下调用。 E3tj/4:L
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<% *^6k[3VY
CountBean cb=new CountBean(); nOuN|q=C
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 2mOfsn d@
CountCache.add(cb); AO8:|?3S
out.print(CountCache.list.size()+"<br>"); 0#
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CountControl c=new CountControl(); P%jkKE?B4
c.run(); [Yoa"K
out.print(CountCache.list.size()+"<br>"); Ltg-w\?]
%>