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: F^$led1/F
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CountBean.java I`(l *U
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/* qml2XJ>
* CountData.java BQ</g* $;
* D('2p8;2"7
* Created on 2007年1月1日, 下午4:44 `?(Bt|<>
* U5HKRO
* To change this template, choose Tools | Options and locate the template under HmmS(fU
* the Source Creation and Management node. Right-click the template and choose g9fq5E<G
* Open. You can then make changes to the template in the Source Editor. `Hx~UH)
*/ @wmi5oExc
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package com.tot.count; 7}O.wUKw%
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/** }ArpPU
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* 2aA`f7
* @author Uggw -sRU
*/ ~tFqb<n
public class CountBean { <|Yj%f
private String countType; qZEoiNH(Tj
int countId; M6r^L6$N
/** Creates a new instance of CountData */ <+#oBN
public CountBean() {} kUx&pYv
public void setCountType(String countTypes){ 3-Dt[0%{
this.countType=countTypes; w2O!M!1
} 98jN)Nl,oD
public void setCountId(int countIds){ xda;
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this.countId=countIds; M]v=-
} U).*q?.z
public String getCountType(){ $*a'84-5G-
return countType; "<+ih0Ma
} T=a=B(
public int getCountId(){ d@0Kr5_
return countId; b
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} ~rr 4ok
} UM*jKi2]"
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CountCache.java #3=P4FUz.
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/* HBE.F&C88
* CountCache.java AGP("U'u
* e(F42;$$
* Created on 2007年1月1日, 下午5:01 4F3x@H'
*
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* To change this template, choose Tools | Options and locate the template under l&YKD,H};
* the Source Creation and Management node. Right-click the template and choose _lKZmhi
* Open. You can then make changes to the template in the Source Editor. . v@>JZC
*/ F(#rQ_z]
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package com.tot.count; )QagS.L{z
import java.util.*; 2g9G{~,@g
/** # {fTgq
* H=g.34
* @author L%}zVCg
*/ ; |/leu8
public class CountCache { "P@>M) -9Z
public static LinkedList list=new LinkedList(); XNMa0
/** Creates a new instance of CountCache */ gk BdR +
public CountCache() {} CRve.e8J
public static void add(CountBean cb){ 4n1; Bh$
if(cb!=null){ %owsBO+
list.add(cb); 9~rUkHD
} Z|9u]xL
} \AUI|M;'
} =$8nUX`
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CountControl.java tj]9~eJ-
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/* *=ZsqOHwG
* CountThread.java U'UQ|%5f
* Ch()P.n?
* Created on 2007年1月1日, 下午4:57 t%zpNd2lk
* /N>e&e[35\
* To change this template, choose Tools | Options and locate the template under 1T_QX9
* the Source Creation and Management node. Right-click the template and choose h0oMTiA
* Open. You can then make changes to the template in the Source Editor. ]9=h%5Ji>
*/ H`8``#-|@S
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package com.tot.count; ,6!rR,0
import tot.db.DBUtils; plu$h-$d
import java.sql.*; p47S^gW
/** &bz:K8c
* 1pv}]&X
* @author l:6,QaT1
*/
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public class CountControl{ ~1m2#>
private static long lastExecuteTime=0;//上次更新时间 R8L_J6Kpa
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 uJR%0 E7!
/** Creates a new instance of CountThread */ U`Jy!x2m
public CountControl() {} .O*bILU
public synchronized void executeUpdate(){ )4?x5#
Connection conn=null; Ed0I WPx
PreparedStatement ps=null; /<CSVJ_r
try{ @\oz4^
conn = DBUtils.getConnection(); v]%WH~>
conn.setAutoCommit(false); *?+V65~dW
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Giq=*D+
for(int i=0;i<CountCache.list.size();i++){ 5WqXo{S
CountBean cb=(CountBean)CountCache.list.getFirst(); O?8Ni=]
CountCache.list.removeFirst(); Nfe>3uQK
ps.setInt(1, cb.getCountId()); $I#q
ps.executeUpdate();⑴ 8;y&Pb~)
//ps.addBatch();⑵ rV({4cIe9R
} f\;65k_jq
//int [] counts = ps.executeBatch();⑶ f"7M^1)h2%
conn.commit(); Z34Wbun4
}catch(Exception e){ ]Q
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e.printStackTrace(); /MB{Pmk$R
} finally{ jEc|]E
try{ IvpcSam'
if(ps!=null) { ;Z j]~|
ps.clearParameters(); +9O5KI?P
ps.close(); 2,vB'CAI
ps=null; 7:]Pl=:X
} 'sp-%YlM -
}catch(SQLException e){} q'oMAM f}
DBUtils.closeConnection(conn); zL5d0_E9
} 8,O33qwH
} %xlqF<
public long getLast(){ v{i7h|e
return lastExecuteTime; =.|J!x
} OI}
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public void run(){ d0hhMx6$
long now = System.currentTimeMillis(); Y
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if ((now - lastExecuteTime) > executeSep) { p\C%%
//System.out.print("lastExecuteTime:"+lastExecuteTime); .yT8NTu~0j
//System.out.print(" now:"+now+"\n"); I9o6k?$K
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); bW#@OrsS
lastExecuteTime=now; wiOgyMdx
executeUpdate(); Y=Z1Tdxa|
} 'tN25$=V&W
else{ iDl;!b&V.
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); AeIrr*~]B
} &)i|$J 2.
} H9 C9P17
} Y\],2[liF
//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 y5= `ap
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类写好了,下面是在JSP中如下调用。 9p$V)qdX
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<% k~%<Ir1V]
CountBean cb=new CountBean(); 2=-utN@Z
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 1%M&CX
CountCache.add(cb); b1pQ`qt
out.print(CountCache.list.size()+"<br>"); CV$],BM
CountControl c=new CountControl(); SUWD]k >PH
c.run(); 6#}93Dgv4
out.print(CountCache.list.size()+"<br>"); L_Q#(in
%>