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: Ut'T!RD
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CountBean.java N;-%:nC
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/* `^^t#sT
* CountData.java aN*{nW
* iZ}c[hC'3`
* Created on 2007年1月1日, 下午4:44 Uvc$&j^k
* t}Td$K7
* To change this template, choose Tools | Options and locate the template under z?Z"*z
* the Source Creation and Management node. Right-click the template and choose d(^HO~p
* Open. You can then make changes to the template in the Source Editor. 6A.%)whI;
*/ %vZHHBylu
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package com.tot.count; rA?<\*
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/** +UX~'t_'v
* <+
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* @author =$y J66e
*/ d6[' [dG
public class CountBean { zvq}7,
private String countType; d*6/1vyjT
int countId; uZ3do|um
/** Creates a new instance of CountData */ z3L=K9)
public CountBean() {} =ca[*0^Z7
public void setCountType(String countTypes){
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this.countType=countTypes; ??.aLeF&
} H$WD7/?j
public void setCountId(int countIds){ l8+)Xk>
this.countId=countIds;
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} }s'=w]m
public String getCountType(){ jz=V*p}6
return countType; NhNd+SCZ@
} y!x[N!a
public int getCountId(){ b|Ge#o
return countId; C_q2bI
} $")Gd@aR
} <
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CountCache.java ND.(N'/O
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/* kjsj~jwvv
* CountCache.java F[jqJzCz
* `~VL&o1>
* Created on 2007年1月1日, 下午5:01 v9 /37AU
* }m^^6h
* To change this template, choose Tools | Options and locate the template under r9M3rj]
* the Source Creation and Management node. Right-click the template and choose QbSLSMoL
* Open. You can then make changes to the template in the Source Editor. YG=:lf
*/ ZWS:-]P.
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package com.tot.count; )l
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import java.util.*; t$VRNZ`dy
/** "0 %fR"
* 8|\ -(:v
* @author VCnf`wZB"
*/ Zon7G6s9`
public class CountCache { :a2[d1
public static LinkedList list=new LinkedList(); G~u$BV'
/** Creates a new instance of CountCache */ kxEq_FX
public CountCache() {} wX6-WQR
public static void add(CountBean cb){ ^q& Rl\
if(cb!=null){ 7CF>cpw
list.add(cb); "'Gq4<&y
} F,VWi$Po\N
} H$^9#{
} SD%3B!cpX
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CountControl.java q\jq9)
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/* 'CJ_&HR
* CountThread.java Uy|!f]"?
* $'d,X@}8
* Created on 2007年1月1日, 下午4:57 1uKIO{d@
* t(PA+~sIp
* To change this template, choose Tools | Options and locate the template under }#E]efjs
* the Source Creation and Management node. Right-click the template and choose A-L)2.M
* Open. You can then make changes to the template in the Source Editor. | ~>7_:
*/ lsj9^z7
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package com.tot.count; FxK!h.C.
import tot.db.DBUtils; 'ta&qp
import java.sql.*; +T*??OW@
/** j p~Tlomp
* Syl 9j]
* @author nB :i G
*/ {hf_Xro&
public class CountControl{ m*)jndXY
private static long lastExecuteTime=0;//上次更新时间 JS\]|~Gd
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 T 8]*bw
/** Creates a new instance of CountThread */ @sZ' --Y
public CountControl() {} T:K}mLSg
public synchronized void executeUpdate(){ #fx"tx6
Connection conn=null; [K4k7$
PreparedStatement ps=null; .)%,R
try{ KdZ=g ZSH
conn = DBUtils.getConnection(); GeB-4img
conn.setAutoCommit(false); K+L9cv4 |*
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); +G!#
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for(int i=0;i<CountCache.list.size();i++){ !J {[XT
CountBean cb=(CountBean)CountCache.list.getFirst(); /?Y4C)G
CountCache.list.removeFirst(); w&es N$2
ps.setInt(1, cb.getCountId()); Mkt_pr
ps.executeUpdate();⑴ %M8Q6
//ps.addBatch();⑵ #a|r
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} o,J8n;"l
//int [] counts = ps.executeBatch();⑶ N^F5J
conn.commit(); m@D :t5
}catch(Exception e){ 9|@5eN:N
e.printStackTrace(); /&@q*L
} finally{ ;F%EW`7
try{ B 2_fCSlg
if(ps!=null) { oL>o*/
ps.clearParameters(); d%q&[<'jf
ps.close(); n^qwE
ps=null; `)w=@9B)"
} &"Cy&[
}catch(SQLException e){} ;Tq4!w'rH
DBUtils.closeConnection(conn); Ag(JSVY
} \7$"i5
} `GY]JVW
public long getLast(){ } 21!b :a
return lastExecuteTime; cL#zE
} OQg}E@LZ
public void run(){ 4 s9^%K\8{
long now = System.currentTimeMillis(); Edcv>}PfE
if ((now - lastExecuteTime) > executeSep) { ) R5[aO
//System.out.print("lastExecuteTime:"+lastExecuteTime); &K=)YpT
//System.out.print(" now:"+now+"\n"); ,PKUgL}w
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); v-!Spf
lastExecuteTime=now; <+%y
executeUpdate(); 1`Bhis9X8
} D^];6\=.i
else{ D6yE/QeK4
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); :y{@=E=XSC
} CL(D&8v8~
} ||7x51-yj
} ,%V%g!6{
//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 Y|/,*,u+
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类写好了,下面是在JSP中如下调用。 =&.9z 4A
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<% u-.nR}DM_
CountBean cb=new CountBean(); ].QzOV'
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); `!ja0Sq]U
CountCache.add(cb); y<v-,b*
out.print(CountCache.list.size()+"<br>"); fp 3`O9+em
CountControl c=new CountControl(); JV!F<
c.run(); EQHCw<e
out.print(CountCache.list.size()+"<br>"); G-vkkNj%e
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