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: )\s{\u
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CountBean.java ?1T)cd*
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/* iH<:wLY&J
* CountData.java <j,ZAA&5%Y
* wj!YYBH
* Created on 2007年1月1日, 下午4:44 R.@ I}>
* j#G4A%_
* To change this template, choose Tools | Options and locate the template under 4
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* the Source Creation and Management node. Right-click the template and choose #Z#rOh
* Open. You can then make changes to the template in the Source Editor. i/E"E7
*/ \f\CK@
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package com.tot.count; q4=Gj`\43
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/** bWWZGl9
* v+Mi"ZAd
* @author L|ZxB7xk
*/ o5LyBUJ
public class CountBean { +i^@QNOa
private String countType; o1lhVM`15
int countId; H c,e&R
/** Creates a new instance of CountData */ =\~<##sRJ
public CountBean() {} dyWj+N5(
public void setCountType(String countTypes){ *ThP->&:(
this.countType=countTypes; c||EXFS}O
} '^B[Krs'Z`
public void setCountId(int countIds){ yUnNf 2i
this.countId=countIds; =D;n#n 7
} =d`w~iC
public String getCountType(){ $ /`X7a{
return countType; Hq$&rNnq\
} wtM1gYl^
public int getCountId(){ h'lqj0
return countId; BK 3oNDy
} Br4[hUV/
} &_cH9zw@
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CountCache.java ;P
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/* cYmgJBG
* CountCache.java w1Txz4JqB
* ?_ 476A
* Created on 2007年1月1日, 下午5:01 Upw`|$1S
* C&|K7Zp0v
* To change this template, choose Tools | Options and locate the template under ;gGq\c
* the Source Creation and Management node. Right-click the template and choose :A7\eN5
* Open. You can then make changes to the template in the Source Editor. \)$:
*/ .jUM';
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package com.tot.count; gFpub_
import java.util.*; y%Rq6P=4Q
/** ^XX_ qC'1
* R_^0Un([
* @author |
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*/ -*A1[Z ?
public class CountCache { P{,A% t
public static LinkedList list=new LinkedList(); Upa F>,kM
/** Creates a new instance of CountCache */ po\(O8#5U
public CountCache() {} BItH0r7
public static void add(CountBean cb){ >{S
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if(cb!=null){ j*\oK@
list.add(cb); .0YcB
} U ,NGV0
} ?;VsA>PV
} !\VzX
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CountControl.java 9>ajhFyOhX
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/*
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* CountThread.java 8WE@ X)e
* r]@T9\9
* Created on 2007年1月1日, 下午4:57 $Qz<:?D
* -Ew>3Q
* To change this template, choose Tools | Options and locate the template under Z`_x|cU?J
* the Source Creation and Management node. Right-click the template and choose ~x7CI
* Open. You can then make changes to the template in the Source Editor. m%0_fNSJ
*/ fMIRr5
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package com.tot.count; Pbd[gKX_
import tot.db.DBUtils; vw 6$v
import java.sql.*; yAAV,?:o[
/** 3 [j,d]\|
* -AD@wn!wCJ
* @author n}b{u@$
*/ +`bnQn]x+
public class CountControl{ 0SU v 5c
private static long lastExecuteTime=0;//上次更新时间 JH| D
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 No"i6R+
/** Creates a new instance of CountThread */ {yv_Ni*6!
public CountControl() {} 8 :WN@
public synchronized void executeUpdate(){ WMHYOJR
Connection conn=null; [n2zdiiBd
PreparedStatement ps=null; [;yKbw!C
try{ F!3p )?
conn = DBUtils.getConnection(); [O<F `u"a
conn.setAutoCommit(false); @<3E`j'p
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6fo\z2
for(int i=0;i<CountCache.list.size();i++){ pV(k6h
CountBean cb=(CountBean)CountCache.list.getFirst(); #1%ahPhR+
CountCache.list.removeFirst(); Ypl;jkHP
ps.setInt(1, cb.getCountId()); Td,d9M
ps.executeUpdate();⑴ -<g[P_#
//ps.addBatch();⑵ +.&P$`;TZj
} -.r"|\1X
//int [] counts = ps.executeBatch();⑶ ^\ln8!;
conn.commit(); ]8OmYU%6V
}catch(Exception e){ <KtL,a=2+
e.printStackTrace(); Het>G{
} finally{ Avyer/{
try{ p ^TCr<=
if(ps!=null) { 3TeRZ=2:*x
ps.clearParameters(); GutiqVP:B
ps.close(); -R1;(n)
ps=null; _,v?rFLE
} 7!(/7U6rP
}catch(SQLException e){} g,o46`6"
DBUtils.closeConnection(conn); 8 l= EL7
} .waj.9&[l
} e2tru_#
public long getLast(){ 1#;^Z3
return lastExecuteTime; J4j:nd
} )h>dD
public void run(){ d:vc)]M>f{
long now = System.currentTimeMillis(); `'P&={p8
if ((now - lastExecuteTime) > executeSep) { AY"wEyNU
//System.out.print("lastExecuteTime:"+lastExecuteTime); *wX[zO+o
//System.out.print(" now:"+now+"\n"); m:~y:.
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |/ 8!PKm
lastExecuteTime=now; I1s= =
executeUpdate(); c=?6`m,"M
} `D=d!!1eUi
else{ P|lDW|}D@
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); n)D
} XhWo~zh"
} o$U{.#
} VG$;ri>
//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 xX{Zh;M&[
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类写好了,下面是在JSP中如下调用。 $T66%wX
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<% `)KGajB
CountBean cb=new CountBean(); |)0Ta9~
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); "cjD-42
CountCache.add(cb); ]BRwJ2< x
out.print(CountCache.list.size()+"<br>"); i-p,x0th
CountControl c=new CountControl(); -ULgVGYKK
c.run(); S5Pn6'w
out.print(CountCache.list.size()+"<br>"); 8WpNlB+:{
%>