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: >*vI:MG8
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CountBean.java k
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/* y4P mL
* CountData.java j~Rh_\>Q
* )]X_')K
* Created on 2007年1月1日, 下午4:44 }w"laZ*
* is#?O5:2
* To change this template, choose Tools | Options and locate the template under Kax85)9u
* the Source Creation and Management node. Right-click the template and choose %8hhk]m\b>
* Open. You can then make changes to the template in the Source Editor. Gq+!%'][P
*/ c1jgBty
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package com.tot.count; #UI@<0P)
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/** &ATjDbW*(
* _oe2pL&
* @author mw?,oiT,)
*/ :N%]<Mq
public class CountBean { o5. q
private String countType; <=^YIp
int countId; 0o(/%31]
/** Creates a new instance of CountData */ QJ>+!p*
public CountBean() {} oy/#,R_n%
public void setCountType(String countTypes){ z4_>6sf{
this.countType=countTypes; j.AAY?L
} <7?MutHM-
public void setCountId(int countIds){ H[!by)H
this.countId=countIds;
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} xjv?Z"X
public String getCountType(){ Rz*%(2Vz
return countType; g%[lUxL
} E]_sl/`{od
public int getCountId(){ -zG/@.
return countId; "mHSbG
} fu\M2"e
} /1o~x~g(b
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CountCache.java '1/uf;OXIH
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/* (Cqhk:F
* CountCache.java )[G5qTO
* A5Y z|
* Created on 2007年1月1日, 下午5:01 S : 9zz
* UT]LF#.(
* To change this template, choose Tools | Options and locate the template under #Z (B4YO
* the Source Creation and Management node. Right-click the template and choose M2vYOg`t:c
* Open. You can then make changes to the template in the Source Editor. ;`s/|v
*/ sh E>gTe
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package com.tot.count; CbI[K|
import java.util.*; z1(rHJd
/** vY}/CBmg
* uK3,V0 yz
* @author X;ijCZb3b
*/ 5wiU4-{
public class CountCache { <Cn-MOoM
public static LinkedList list=new LinkedList(); NfDg=[FN[
/** Creates a new instance of CountCache */ AdR}{:ia
public CountCache() {} dhsQfWg#}
public static void add(CountBean cb){ W@#)8];>
if(cb!=null){ @<AyCaU`.
list.add(cb); *,@dt+H!y
} ~Ci|G3BW
} F|%[s|s
} Xxp<qIEm
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CountControl.java k +&LOb7
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/* fh}\#WE"
* CountThread.java ([tbFI}A
* v#nYH?+~mJ
* Created on 2007年1月1日, 下午4:57 |u7vY/
* `NyvJt^<
* To change this template, choose Tools | Options and locate the template under _z{:Q
* the Source Creation and Management node. Right-click the template and choose JEs?Rm1^.
* Open. You can then make changes to the template in the Source Editor. b":cj:mxL
*/ YM/GSSq
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package com.tot.count; Th'6z#h:U
import tot.db.DBUtils; :hCp@{
import java.sql.*; g' H!%<
/** 8L6!CP_!
* ?psvhB{O
* @author UR:cBr
*/ zD7\Gv
public class CountControl{ kImS'i{A
private static long lastExecuteTime=0;//上次更新时间 ;r"YZs&Xd
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ^szCf|SM
/** Creates a new instance of CountThread */ :TX!lbCq
public CountControl() {} V!a\:%#^Y
public synchronized void executeUpdate(){ @/E5$mX`
Connection conn=null; YRAWylm
PreparedStatement ps=null; e>z3\4
try{ pDr M8)r
conn = DBUtils.getConnection(); \h,S1KmIBD
conn.setAutoCommit(false); /\_0daUx
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); j<Lj1P3
for(int i=0;i<CountCache.list.size();i++){ >z.o?F
CountBean cb=(CountBean)CountCache.list.getFirst(); $ R,7#7bG
CountCache.list.removeFirst(); ,eF}`
ps.setInt(1, cb.getCountId()); PIsMx -i0
ps.executeUpdate();⑴ d^!)',`
//ps.addBatch();⑵ 89k9#i X
} [8(e`6xePb
//int [] counts = ps.executeBatch();⑶ ~4`LOROC
conn.commit(); -*M/,O
}catch(Exception e){ 'k{pWfn=<
e.printStackTrace(); 8{(;s$H~
} finally{ p\WW~qD
try{ yL7a*C&
if(ps!=null) { gj0gs
ps.clearParameters(); NYm2fFPc
ps.close(); RxjC sjg
ps=null; y4w{8;Mh
} t+|c)"\5h
}catch(SQLException e){} (kK6=Mrf
DBUtils.closeConnection(conn); ^8ZVB.Fv
} a=.A/;|0*
} "z1\I\
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public long getLast(){ $*\[I{Zau}
return lastExecuteTime; jyb/aov
} )F8G q,
public void run(){ WIa4!\Ky!
long now = System.currentTimeMillis(); \|L ~#{a
if ((now - lastExecuteTime) > executeSep) { vxzh|uF
//System.out.print("lastExecuteTime:"+lastExecuteTime); pGc_Klq
//System.out.print(" now:"+now+"\n"); %J5zfNe)&
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ^%VMp>s
lastExecuteTime=now; 4ac2^`
executeUpdate(); FI`][&]V
} J/:9;{R
else{ Pa'g=-
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Rs$k3
} "\Zsr6y
} 4nN%5c~=
} 9r+]V=
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 PxhB=i!'$
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类写好了,下面是在JSP中如下调用。 RLu y;z
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<% pd?3_yU
CountBean cb=new CountBean(); U,_uy@fE=?
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ps\A\aggML
CountCache.add(cb); _?x*F?5=
out.print(CountCache.list.size()+"<br>"); =6y4* f
CountControl c=new CountControl(); WZOi,
c.run();
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out.print(CountCache.list.size()+"<br>"); n,!PyJ
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