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: e
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CountBean.java 7P%%p3
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/* .\\DKh%
* CountData.java _mzW'~9wN
* O#n8=B4
* Created on 2007年1月1日, 下午4:44 Hta y-PB }
* ynmWW^dg
* To change this template, choose Tools | Options and locate the template under <>n0arAn
* the Source Creation and Management node. Right-click the template and choose >Y&N8PHD
* Open. You can then make changes to the template in the Source Editor. wc0jhHZO
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*/ IrR7"`.i
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package com.tot.count; P]<4R:yb
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/** tf=6\p
* T!-\@PB !
* @author y>R=`A1b
*/ 9V'%<pk''(
public class CountBean { [=x[ w70
private String countType; CWf /H)~
int countId; ;5wn67'
/** Creates a new instance of CountData */ `Y+J-EQ
public CountBean() {} :Gv1?M
public void setCountType(String countTypes){ ~fBtQGdX
this.countType=countTypes; WKQ^NEqr3
} =Ee&da^MB
public void setCountId(int countIds){ ~{?_p@&n
this.countId=countIds; /Y*WBTV'
} ]fm'ZY&
public String getCountType(){ 4]rnY~
return countType; pny11C
} ylUrLQ\
public int getCountId(){ .v]IJfRH*
return countId; Hh%I0#
} Jx_cf9{
} BoA/6FRi[
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CountCache.java k=2Lo
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/* *zNYZ#
* CountCache.java V
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* %`k6w3qI
* Created on 2007年1月1日, 下午5:01 9 ^o-EC!_
* VJ84?b{c
W
* To change this template, choose Tools | Options and locate the template under y9_V
* the Source Creation and Management node. Right-click the template and choose ]~844Jp
* Open. You can then make changes to the template in the Source Editor. ioaU*%
*/ OHv[#xGuV?
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package com.tot.count; SD#]$v
import java.util.*; M])ZK
/** )W|w C#
* -T!f,g3vW
* @author ~"dA~[r
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*/ 4p e'06:
public class CountCache { RFKtr
public static LinkedList list=new LinkedList(); YW-usvl&
/** Creates a new instance of CountCache */ X#d~zk[r2
public CountCache() {} J2d.f}-
public static void add(CountBean cb){ s.EI`*xylY
if(cb!=null){ eD-#b|
list.add(cb); R|JC1f8P5
} `id9j
} mCRt8rY;
} ?m![Pg%
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CountControl.java U!T~!C^
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/* w'L\?pI
* CountThread.java mrTlXXz
* A+HF@Uw}^
* Created on 2007年1月1日, 下午4:57 <Q$@r?Mu]
* r[1i*b$
* To change this template, choose Tools | Options and locate the template under :WQ^j!9'
* the Source Creation and Management node. Right-click the template and choose ko1J094Y%
* Open. You can then make changes to the template in the Source Editor. 0,r}o
*/ tzZ63@cm
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package com.tot.count; ckV`OaRw4
import tot.db.DBUtils; oV)~@0B&0
import java.sql.*; avjpA?Vz
/** aGK?x1_
* @*>@AFnf\Z
* @author )@N2
*/ UYFwS/ RW}
public class CountControl{ [N1hWcfvd
private static long lastExecuteTime=0;//上次更新时间 )_a~}
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private static long executeSep=60000;//定义更新间隔时间,单位毫秒 b`L%t:u{d
/** Creates a new instance of CountThread */ Cv
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public CountControl() {} "~`I::'c
public synchronized void executeUpdate(){ Z.d7U~_
Connection conn=null; ekI2icD
PreparedStatement ps=null; - *F(7$
try{ jATI&oX
conn = DBUtils.getConnection(); R=.4
conn.setAutoCommit(false); S2n39 3
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); yPM3a7-Bm
for(int i=0;i<CountCache.list.size();i++){ ]FD'5p{
CountBean cb=(CountBean)CountCache.list.getFirst(); t'9*R7=
CountCache.list.removeFirst(); u?>B)PW
ps.setInt(1, cb.getCountId()); DQMHOd7g
ps.executeUpdate();⑴ cQG
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//ps.addBatch();⑵ ?/TSi0R
} rJFc({ 0
//int [] counts = ps.executeBatch();⑶ qNI,
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conn.commit(); 0 - ><q
}catch(Exception e){ (Lo%9HZ1Mx
e.printStackTrace(); e'~Zo9`r6
} finally{ 5'0xz.)!
try{ X_qf"|i
if(ps!=null) { g wz7krUTe
ps.clearParameters(); rX*H)3F
ps.close(); ;g6M%;1-
ps=null; *eIJwXE
} pp.6Ex
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}catch(SQLException e){} 6)z?f4,
DBUtils.closeConnection(conn); ay1YOfa*
} {)DHH:n
} 6Z#\CixG
public long getLast(){ $f,n8]
return lastExecuteTime; Sa\!*e_sN
} f?oa"
public void run(){ ng:kA%!
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long now = System.currentTimeMillis(); n$U#:aQE
if ((now - lastExecuteTime) > executeSep) { "~=mG--I
//System.out.print("lastExecuteTime:"+lastExecuteTime); IC6gU$e
//System.out.print(" now:"+now+"\n"); u583_k%
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); $k0kk
lastExecuteTime=now; lAzjN~V
executeUpdate(); |UP `B|
} @lCJ G!u
else{ 7~&/_3
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); PN0VQ/..
} 1J6,]M
} "oWwc
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} MepuIh
//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 !icT/5
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类写好了,下面是在JSP中如下调用。 V~S0hqW[
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<% ~ns7O
CountBean cb=new CountBean(); HQ|MhM/"
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); +zu(
CountCache.add(cb); Qd=^S^}(
out.print(CountCache.list.size()+"<br>"); V?Z.\~
CountControl c=new CountControl(); OS4q5;1#
c.run(); qP2ekI:y
out.print(CountCache.list.size()+"<br>"); 7a#4tqM#
%>