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: aZGDtzNG5h
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CountBean.java _x1[$A,GuB
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/* y@\Q@
9
* CountData.java ?QT"sj64w
* HTyF<K
* Created on 2007年1月1日, 下午4:44 ~7WXjVZ
* \+Ln~\Sv
* To change this template, choose Tools | Options and locate the template under ]Ja8i%LjOG
* the Source Creation and Management node. Right-click the template and choose e4%*I8
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* Open. You can then make changes to the template in the Source Editor. e`M]ZGrr
*/ H<7DcwXv
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package com.tot.count; ruA+1-<f
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/** ;Jn0e:x`E
* -7z y
* @author e -]c
*/ &dDI*v+
public class CountBean { _Ge^
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private String countType; 5=h'!|iY
int countId; 1$D`Z/N"A
/** Creates a new instance of CountData */ e0WSHg=6@
public CountBean() {} |aAWWd5
public void setCountType(String countTypes){ =C>`}%XT}
this.countType=countTypes; |abst&yp
} U3+_'"
public void setCountId(int countIds){ <i\zfa'6
this.countId=countIds; 'Mx K}9
} 7r[%|:
public String getCountType(){ bNpIC/#0K
return countType; 'L|GClc6)
} 'S4EKV]
public int getCountId(){
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return countId; RzJ}C T
} p6y0W`U
} &DQ4=/Z
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CountCache.java eGe[sv"k
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/* K[>@'P}y
* CountCache.java UtBlP+bE?y
* i,Wm{+H-O
* Created on 2007年1月1日, 下午5:01 Pn'(8bRm
* nB@iQxcz
* To change this template, choose Tools | Options and locate the template under $:BK{,\
* the Source Creation and Management node. Right-click the template and choose _[vdY|_
* Open. You can then make changes to the template in the Source Editor. Sa?5iFg
*/ syW9Hlm
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package com.tot.count; oD#<?h)(
import java.util.*; }#W`<,*rL.
/** n]C%(v!u3
* =Q8H]F
* @author 8Z4?X%
*/ P-OPv%jyi
public class CountCache {
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public static LinkedList list=new LinkedList(); *&dW\fx
/** Creates a new instance of CountCache */ q]i(CaKh
public CountCache() {} f{^M.G@
public static void add(CountBean cb){ k#Ez
if(cb!=null){ <K#'3&*$s
list.add(cb); (4/]dTb
} x
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} !`
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} 3q|cZQK!1
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CountControl.java JXLWRe
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/* @ "{' j
* CountThread.java 5h|m4)$
* U.hERe~X
* Created on 2007年1月1日, 下午4:57 P7wqZ?
* Z]aK'
* To change this template, choose Tools | Options and locate the template under aq0iNbv@
* the Source Creation and Management node. Right-click the template and choose s@ 20#D
* Open. You can then make changes to the template in the Source Editor. ^?s~Fk_V
*/ R7B,Q(q2-
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package com.tot.count; gVnwsE
import tot.db.DBUtils; KM6N'x ^z
import java.sql.*; Y1fy2\<'
/** @k+%y'Y?
* q
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* @author .A*VLF*m
*/ oGJ*Rn)Z
public class CountControl{ W%>i$:Qq
private static long lastExecuteTime=0;//上次更新时间 XYb^Cs;
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 KZrMf77=
/** Creates a new instance of CountThread */ iF [?uF
public CountControl() {} hEv=T'*,K)
public synchronized void executeUpdate(){ CP]S-o}yd
Connection conn=null; k'@7ZH
PreparedStatement ps=null; z;y^t4
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try{ ljYpMv.>xG
conn = DBUtils.getConnection(); aVppOxA
conn.setAutoCommit(false); -3G 4vRIo
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); _)zmIB(}m
for(int i=0;i<CountCache.list.size();i++){ ws>WA{]gq
CountBean cb=(CountBean)CountCache.list.getFirst(); BSfm?ku"!
CountCache.list.removeFirst(); /UpD$,T|^|
ps.setInt(1, cb.getCountId()); ~MhgAC
ps.executeUpdate();⑴ 2JiAd*WK
//ps.addBatch();⑵ :WK"-v
} _(oP{wgB
//int [] counts = ps.executeBatch();⑶ vv2vW=\
conn.commit(); ~_u*\]-
}catch(Exception e){ P.LuF(?$
e.printStackTrace(); g5tjj.
} finally{ Q e>i{:N
try{ G`]v_`>
if(ps!=null) { x)ddRq
l
ps.clearParameters(); |*tWF!
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ps.close(); IpWy)B>Fl3
ps=null; $hjP}- oUX
} OU,PO2xX9
}catch(SQLException e){} =My}{n[
DBUtils.closeConnection(conn); &Y54QE".
} 0%xR<<gir
} 3XeXzPj
public long getLast(){ 9;0V
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return lastExecuteTime; )-+\M_JK5
} j3x^<a\gJ
public void run(){ <%d51~@={I
long now = System.currentTimeMillis(); .KLm39j(
if ((now - lastExecuteTime) > executeSep) { nT.L}1@
//System.out.print("lastExecuteTime:"+lastExecuteTime); aO.\Qe+j
//System.out.print(" now:"+now+"\n"); w4e%-Ln
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); h4CTTe)
lastExecuteTime=now; =tr1*s{
executeUpdate(); RzA2*]%a
} E`Jp(gK9F
else{
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); <w0NPrS]
} vKNt$]pm=
} q2x|%HRF
}
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//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 AbUDn\0$
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类写好了,下面是在JSP中如下调用。 {&2$[g=[ ^
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<% _:35d1[
CountBean cb=new CountBean(); B{7Kzwh;
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 1. #
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CountCache.add(cb); "?apgx 6
out.print(CountCache.list.size()+"<br>"); j5L)N
CountControl c=new CountControl(); KX?o
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c.run(); T-4/d5D[
out.print(CountCache.list.size()+"<br>"); xGYSi5}z
%>