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: V zx%N.
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CountBean.java Z{ntF
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/* PAe2hJ
* CountData.java zN\~v
* C/P,W>8
* Created on 2007年1月1日, 下午4:44 {C%/>e2-%
* N_vVEIO9
* To change this template, choose Tools | Options and locate the template under %@!Vx
* the Source Creation and Management node. Right-click the template and choose HY]vaA`
* Open. You can then make changes to the template in the Source Editor. 5k`[a93T
*/ X;5U@l
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package com.tot.count; @"}dbW <DV
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/** `p&ko$i2
* >#@1
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* @author -(n[^48K
*/ 6TE RQ
public class CountBean { ?l_>rSly5
private String countType;
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int countId; b'$j* N
/** Creates a new instance of CountData */ ;8~`fK
public CountBean() {} @1#$
public void setCountType(String countTypes){ vf@d(g
this.countType=countTypes; 6e@
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} AJrwl^lm
public void setCountId(int countIds){ cU25]V^{\
this.countId=countIds; 5 TD"
} lLHHuQpuj
public String getCountType(){ -Uz
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return countType; 1K'0ajl1A
} q{UP_6OF
public int getCountId(){ %PG::b
return countId; y(:hN)
} `4cs.ab
} r'hr'wZ
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CountCache.java `hM:U
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/* O.=~/!(
* CountCache.java {6<7M
* US)wr
* Created on 2007年1月1日, 下午5:01 h<*l=`#
* xZ@H{):
* To change this template, choose Tools | Options and locate the template under z9$x9u
* the Source Creation and Management node. Right-click the template and choose VEd#LSh
* Open. You can then make changes to the template in the Source Editor. O0"i>}g4
*/ a4,bP*H
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package com.tot.count; {e2 (
import java.util.*; [E(DGt
/**
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* 1!\!3xa V
* @author )J_!ZpMC
*/ rsfA.o
public class CountCache { jh]wHG
public static LinkedList list=new LinkedList(); OgrUP
/** Creates a new instance of CountCache */ ;T6^cS{ Gj
public CountCache() {} Cc]s94
public static void add(CountBean cb){ ~}4o=O(
if(cb!=null){ ^ h^2='p
list.add(cb); f?F
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} 8'*z>1ZS5
} BzA(yCu$:
} ,ewg3mYHC&
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CountControl.java dv%gmUUf}k
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/* /,5`#Gte_
* CountThread.java >w9)c|
* q4 'x'8
* Created on 2007年1月1日, 下午4:57 |Xd[%W)
* 5 v~Y>
* To change this template, choose Tools | Options and locate the template under $'X*L e@k
* the Source Creation and Management node. Right-click the template and choose n<CJx+U
* Open. You can then make changes to the template in the Source Editor. )QTk5zt
*/ xn@?CP`-y
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package com.tot.count; hC]c
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import tot.db.DBUtils; jjvm<;lv
import java.sql.*; .,,?[TI
/** T]EXm/
* Sct-,K%i
* @author Rv q_Zsm
*/ ER5Q` H
public class CountControl{ v5wI?HE
private static long lastExecuteTime=0;//上次更新时间 X>%2\S
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ]-%ZN+
/** Creates a new instance of CountThread */ -5vc0"?E
public CountControl() {} 30>TxL=&
public synchronized void executeUpdate(){ R_vZh|
Connection conn=null; 2t[c^J
PreparedStatement ps=null; u{H,i(mx?
try{ r'&9'rir2
conn = DBUtils.getConnection(); Ffj:xZ9rk
conn.setAutoCommit(false); r=L9x/r
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?");
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for(int i=0;i<CountCache.list.size();i++){ wc bs-arH
CountBean cb=(CountBean)CountCache.list.getFirst(); /GM-#q
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CountCache.list.removeFirst(); 2y_rsu\
ps.setInt(1, cb.getCountId()); J~gfMp.
ps.executeUpdate();⑴ f`A
//ps.addBatch();⑵ T,7Y7MzF
} lu(G3T8
//int [] counts = ps.executeBatch();⑶ (P`{0^O"}
conn.commit(); ]N=C%#ki!
}catch(Exception e){ .2xypL8(
e.printStackTrace(); Oku4EJFJ
} finally{ m3_e]v3{o
try{ GeHDc[7
if(ps!=null) { >+vWtO2
ps.clearParameters(); ?]9uHrdsN}
ps.close(); .[1A
ps=null; h*%T2
} U"m!f*a
}catch(SQLException e){} N%r}0
DBUtils.closeConnection(conn); 7=QV ^G
} D<++6HN
} Mh+'f 93
public long getLast(){ >j`*-(`2fa
return lastExecuteTime; 0^E!P>
} :WA o{|&
public void run(){ qZ\zsOnp
long now = System.currentTimeMillis(); "mPa>`?
if ((now - lastExecuteTime) > executeSep) { sWavxh8A
//System.out.print("lastExecuteTime:"+lastExecuteTime); x;Gyo
//System.out.print(" now:"+now+"\n"); j~Gu;%tq
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); bq(*r:`"
lastExecuteTime=now; [PX'Jer
executeUpdate(); BLaXp0
} &2xYG{Z
else{ Jh466;
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); pHg8(ru|
} lh#GD"^(w&
} wkJB5i^<w
} GV[%P
//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 :!} zdeRJ
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类写好了,下面是在JSP中如下调用。 E0O{5YF^T
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<% ^w&TTo(
CountBean cb=new CountBean(); )D[xY0Y~
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); }7.q[ ^oF
CountCache.add(cb); EL}v>sC
out.print(CountCache.list.size()+"<br>"); M;iaNL(
CountControl c=new CountControl(); *|E@81s#
c.run(); _ZS<zQ'
out.print(CountCache.list.size()+"<br>"); X! 2|_
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