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: /$n ~lf
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CountBean.java @4%L36k
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/* I"AYWo?
* CountData.java >$gG/WD?KR
* l?Y_~Wuw
* Created on 2007年1月1日, 下午4:44 WqxUX H
* syx\gz
* To change this template, choose Tools | Options and locate the template under *5sBhx
* the Source Creation and Management node. Right-click the template and choose JB</euyV
* Open. You can then make changes to the template in the Source Editor. _u"nvgVz9
*/ f:zFFpP.j@
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package com.tot.count; Bhqft;Nuh
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/** U,/6;}
* rA0,`}8\
* @author 2)?(R;$,
*/ 0U66y6
public class CountBean { gw+9x<e
private String countType; {qKxz9.y
int countId; v]2S`ffP
/** Creates a new instance of CountData */
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public CountBean() {} #5sD{:f`
public void setCountType(String countTypes){ k)S.]!u&G
this.countType=countTypes; *IlaM'[*
} Kzy/9
public void setCountId(int countIds){ !.7udYmB
this.countId=countIds; 5q{h 2).)
} ufa41$B'yG
public String getCountType(){ OYM@szM
return countType; ^IZ)#1U
} nM=e]qH
public int getCountId(){ g}&hl"j
return countId; a\kb^D=T
} Nd:R"
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} `T/~.`R
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CountCache.java F0~k1TDw
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/* ?wMHS4
* CountCache.java kI*(V[i
* Xog/O i
* Created on 2007年1月1日, 下午5:01 ,p{`pma
* L;_c|\%
* To change this template, choose Tools | Options and locate the template under MFJE6ei
* the Source Creation and Management node. Right-click the template and choose <j}lp-
* Open. You can then make changes to the template in the Source Editor. c- $Gpa}M
*/ RnVtZ#SCh
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package com.tot.count; Q^}%c
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import java.util.*; 0m[dP
/** `U!y&Q$,
* 4kp im
* @author TGT$ >/w >
*/ wbbqt0un
public class CountCache { (lA.3 4.p
public static LinkedList list=new LinkedList(); <dA8
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/** Creates a new instance of CountCache */ k>4qkigjc
public CountCache() {} Qx|H1_6
public static void add(CountBean cb){ E
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if(cb!=null){ tury<*
list.add(cb); *#>F.#9
} WiNT;v[
} 6,Hqb<(
} &znH!AQ0
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CountControl.java P=AS>N^yaL
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/* 4Tzd; P6_
* CountThread.java *xRc *
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* jX=lAs~6
* Created on 2007年1月1日, 下午4:57 H(+<)qH
* .;/L2Jv
* To change this template, choose Tools | Options and locate the template under `%K`gYhG1
* the Source Creation and Management node. Right-click the template and choose -=$2p0"R
* Open. You can then make changes to the template in the Source Editor. :bM+&EP
*/ U0B2WmT~Q
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package com.tot.count; XaI;2fMGI
import tot.db.DBUtils; @B1{r|-<^
import java.sql.*; ^~ =9
/** b=##A
* bPD)D'Hs
* @author IxSV? k
*/ uq7T{7~<
public class CountControl{ T(X:Yw
private static long lastExecuteTime=0;//上次更新时间 y+mElG$F
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 U)jUq_LX
/** Creates a new instance of CountThread */ >O{7/)gS^
public CountControl() {} -<f/\U
public synchronized void executeUpdate(){ H>7dND2;
Connection conn=null; mL L$|
PreparedStatement ps=null; @Z(rgF{{
try{ _uH9XGm
conn = DBUtils.getConnection(); /F[+13C
conn.setAutoCommit(false); ,cHU) j
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 0A$SYF$O+[
for(int i=0;i<CountCache.list.size();i++){ ^tAO_~4
CountBean cb=(CountBean)CountCache.list.getFirst(); _."E%|5
CountCache.list.removeFirst(); q|#MB7e/
ps.setInt(1, cb.getCountId()); y).P=z
ps.executeUpdate();⑴ LVtu*k
//ps.addBatch();⑵ _g|acBF
} J%v5d*$.
//int [] counts = ps.executeBatch();⑶ Q}vbm4)[
conn.commit(); 83;IyvbL
}catch(Exception e){ =G>(~+EA
e.printStackTrace(); )q^ Bj$
} finally{ ~uaP$*B[
try{ \P?ToTTV
if(ps!=null) { :X>DkRP
ps.clearParameters(); ?X_V#8JK
ps.close(); 3{J.xWB@:
ps=null; 1p\Ak
} w+UV"\!G)Q
}catch(SQLException e){} "n?<2
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DBUtils.closeConnection(conn); YB!!/ SX4
} UmP'L!
} (aKZ5>>cN
public long getLast(){ Ti= 3y497S
return lastExecuteTime; cdp0!W4Gi
} R_e)mkE
public void run(){ c~tAvDX
long now = System.currentTimeMillis(); R{3CW^1
if ((now - lastExecuteTime) > executeSep) { d'zT:g
//System.out.print("lastExecuteTime:"+lastExecuteTime); Z;<ep@gy~
//System.out.print(" now:"+now+"\n"); F$Pp]"82'm
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); lizTRVBE
lastExecuteTime=now; gue(C(~.k_
executeUpdate(); h5onRa*7
} tV`&-H
else{ ROoE%%8I
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); D VwCx^
} a-PGW2G
} c4|so=
} &'O?es|Lb
//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 h~ha
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类写好了,下面是在JSP中如下调用。 gMZ&,n4
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<% G[6=u|(M
CountBean cb=new CountBean(); &%e"9v2`
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [ X|OrRA
CountCache.add(cb); t<lyg0f
out.print(CountCache.list.size()+"<br>"); raQYn?[
CountControl c=new CountControl(); ^Kw(&v
c.run(); AQ}l%
out.print(CountCache.list.size()+"<br>"); faVS2TN4
%>