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: u;+8Jg+xH/
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CountBean.java _qk
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/* EvH/d4V;
* CountData.java Vh>|F}%E
* u U%Z%O
* Created on 2007年1月1日, 下午4:44 QseV\; z
* ZG-#YF.1
* To change this template, choose Tools | Options and locate the template under GL~
Wnt
* the Source Creation and Management node. Right-click the template and choose -fp/3-
* Open. You can then make changes to the template in the Source Editor. o`G6!
*/ -ijzo%&qA
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package com.tot.count; _D$1CaAYo
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/** xT(0-o*
* W]XM<# ^^
* @author hV:++g
*/ "!CVm{7[
public class CountBean { p=3t!3
private String countType; HJBGxyw
int countId; N3N~z1x0h
/** Creates a new instance of CountData */ gu:vf/
public CountBean() {} F{^\vFp
public void setCountType(String countTypes){ Z_fwvcZ?05
this.countType=countTypes; P^!g0K
} ,:2Z6~z{
public void setCountId(int countIds){ |?nYs>K
this.countId=countIds; $@O?
} eK5~YM:o
public String getCountType(){ ug.|ag'R
return countType; |P`b"x
} }Xfg~%6
public int getCountId(){ Bh'!aip k
return countId; kR3wbA
} vxOnv8(
} (E7"GJ
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CountCache.java pU'${Z~b
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/* EV-sEl8ki
* CountCache.java _>BYUPY
* HDTA`h?t;
* Created on 2007年1月1日, 下午5:01 hnH<m7
* }a#T\6rY
* To change this template, choose Tools | Options and locate the template under ||fw!8E
* the Source Creation and Management node. Right-click the template and choose yYSmmgrX0
* Open. You can then make changes to the template in the Source Editor. Ghc
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*/ %?, 7!|Ls
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package com.tot.count; Uk*(C(
import java.util.*; k`&FyN^)
/** }V*?~.R
* `Tf}h8*
* @author ` &bF@$((
*/ kvuRT`/
public class CountCache { 6212*Z_Af
public static LinkedList list=new LinkedList(); 'n>44_7 L
/** Creates a new instance of CountCache */ %hN(79:g
public CountCache() {} ]uF7HX7F
public static void add(CountBean cb){ E_I-.o|
if(cb!=null){ y10W\beJ
list.add(cb); h Ypj
} `"PHhCG+z
} ! L|l(<C
} e$_gOwB
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CountControl.java B8?9L8M}
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/* kZo#Ny
* CountThread.java w\0vP
* +H?g9v40
* Created on 2007年1月1日, 下午4:57 VcXr!4M
* ""
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* To change this template, choose Tools | Options and locate the template under ,A7:zxnc.V
* the Source Creation and Management node. Right-click the template and choose Pz[UAJ
* Open. You can then make changes to the template in the Source Editor. mdyl;e{0
*/ n1GX`K
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package com.tot.count; 65JG#^)KaX
import tot.db.DBUtils; *0Z6H-Do,
import java.sql.*; 3 !8#wn
/** (9ZW^flY
* G_5{5Ar
* @author Y0kcxpK/
*/ }!k?.(hpE
public class CountControl{ 9H;Os:"\|
private static long lastExecuteTime=0;//上次更新时间 }yn%_KQ0
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 gK;dfrU.8Y
/** Creates a new instance of CountThread */ qoH:_o8ClO
public CountControl() {} {5D%<Te
public synchronized void executeUpdate(){ aMGh$\Pg
Connection conn=null; fa,:d8
PreparedStatement ps=null; ,jeHL@>w[
try{ 74:( -vS
conn = DBUtils.getConnection(); Te~jYkCd
conn.setAutoCommit(false); |f$ws R`&
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); f*rub. y
for(int i=0;i<CountCache.list.size();i++){ DJ7ak>"R
CountBean cb=(CountBean)CountCache.list.getFirst(); jtpHDS
CountCache.list.removeFirst(); 1%vE 7a>{
ps.setInt(1, cb.getCountId()); _Dqi#0#40p
ps.executeUpdate();⑴ Lg(G&ljE@k
//ps.addBatch();⑵ V`LE 'E
} j^8HTa0Cy|
//int [] counts = ps.executeBatch();⑶ BTj1C
conn.commit(); H_3WxfO
}catch(Exception e){ W`JI/
e.printStackTrace(); 1 oKY7i$
} finally{ &&52ji<3
try{ h$$JXf
if(ps!=null) { R[6R)#o
ps.clearParameters(); r}e(MT:R'
ps.close(); Q?LzL(OioN
ps=null; 7VZ ^J`3
} l l*g *zt3
}catch(SQLException e){} +PWm=;tcC
DBUtils.closeConnection(conn); ~,};FI
} yK"\~t[@X:
} Qi dI
public long getLast(){ w5s&Ws
return lastExecuteTime; w5)KWeGa
} "N_@q2zF
public void run(){ zVtTv-DU
long now = System.currentTimeMillis(); EZ/_uj2&SN
if ((now - lastExecuteTime) > executeSep) { )
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//System.out.print("lastExecuteTime:"+lastExecuteTime); mZ? jpnd
//System.out.print(" now:"+now+"\n"); PWvT C`?
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ~N| aCi-X
lastExecuteTime=now; bA Yp }
executeUpdate(); NX(IX6^y
} SeS ZMv
else{ *c/| /
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); % rnRy<9
} YqXN|&
} }j1;0 kb?
} W7~_XI
//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 >YXb"g@.
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类写好了,下面是在JSP中如下调用。 y]obO|AH
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<% r/0#D+A
CountBean cb=new CountBean(); 7^Us
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); q[vO
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CountCache.add(cb); S/y(1.wh
out.print(CountCache.list.size()+"<br>"); RT'5i$q[
CountControl c=new CountControl(); d^$cx(2$D
c.run(); GmJ
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out.print(CountCache.list.size()+"<br>"); zK1\InP
%>