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: M|h3Wt~7
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CountBean.java PC8Q"O
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/* hn@08t G
* CountData.java U7F!Z(
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* B9z?mt'|r)
* Created on 2007年1月1日, 下午4:44 JH9J5%sp
* LH% F8
* To change this template, choose Tools | Options and locate the template under vvMT}-!
* the Source Creation and Management node. Right-click the template and choose CAhXQ7w'Z
* Open. You can then make changes to the template in the Source Editor. gr2U6gi
*/ 7JH6A'&
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package com.tot.count; $s:aW^k
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/** Qw*|qGvy^
* C&%_a~
* @author {VRf0c
*/ "KpGlY?^
public class CountBean { H7n>Vx:L-
private String countType; 0{D'n@veP
int countId; va@Lz&sAE%
/** Creates a new instance of CountData */ k4J+J.|
public CountBean() {} !F$6-0%
public void setCountType(String countTypes){ gwMNYMI
this.countType=countTypes; F$]Pk|,
}
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public void setCountId(int countIds){ ;A*]l'[-
this.countId=countIds; XRi8Gpg
} A;M'LM- M
public String getCountType(){ CD~.z7,LC
return countType; }Sv:`9=
} :"c*s4
public int getCountId(){ PJH&
return countId; Z FL~;_r
} :$c
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} y<Ot)fa$
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CountCache.java 4tBYR9|
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/* {P_.~0pc*
* CountCache.java S,he6zS
* ?Ir:g=RP*
* Created on 2007年1月1日, 下午5:01
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*
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* To change this template, choose Tools | Options and locate the template under OneY_<*a<
* the Source Creation and Management node. Right-click the template and choose K}Qa~_
* Open. You can then make changes to the template in the Source Editor. w}L[u
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*/ +ZP7{%
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package com.tot.count; H Pz+Dm
import java.util.*; S_H+WfIHV'
/** p!%pP}I
* xAm6BB
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* @author 1'8YkhQ2a
*/ ;O,jUiQ
public class CountCache { J{G?-+`
public static LinkedList list=new LinkedList(); F#E3q|Q"BS
/** Creates a new instance of CountCache */ !&E-}}<
public CountCache() {} mt.))#1
public static void add(CountBean cb){ FS1z`wYP
if(cb!=null){ #/37V2E
list.add(cb); ,V}WM%Km
} |_U= z;Y
} COlaD"Y
} oXgcc*j
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CountControl.java \~ wMfP8
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/* alb.g>LNPP
* CountThread.java |y!A&d=xYn
* d #wVLmKZ
* Created on 2007年1月1日, 下午4:57 xgtR6E^k
* %&bY]w
* To change this template, choose Tools | Options and locate the template under 69.NPy@
* the Source Creation and Management node. Right-click the template and choose &%Tj/ Qx
* Open. You can then make changes to the template in the Source Editor. =2x^nW
*/ PPsE${!
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package com.tot.count; u]@['7
import tot.db.DBUtils; Rf1x`wml
import java.sql.*; x,V r=FB
/** jc9y<{~x/
* v &+R^iLE
* @author $ME)#(
*/ Z?z.?ar
public class CountControl{ U/BR*Zn]*
private static long lastExecuteTime=0;//上次更新时间 Tm?# M&'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 {(}By/_
/** Creates a new instance of CountThread */ Y <qm{e
public CountControl() {} 9_s`{(0?
public synchronized void executeUpdate(){ ?bu>r=oIO]
Connection conn=null; nQS|Lt_+
PreparedStatement ps=null; :Ux_qB
try{ HpnWoDM
conn = DBUtils.getConnection(); 8~gLqh8^V
conn.setAutoCommit(false); !f6(Zho
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); @=kSo
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for(int i=0;i<CountCache.list.size();i++){ )dSi/
CountBean cb=(CountBean)CountCache.list.getFirst(); DlNX 3
CountCache.list.removeFirst(); ;bhT@aB1
ps.setInt(1, cb.getCountId()); ;A!BVq
ps.executeUpdate();⑴ OZ!^ak
//ps.addBatch();⑵ 1aABzB
^
} wlmRe`R
//int [] counts = ps.executeBatch();⑶ `@s^(hc7i
conn.commit(); X\F|Tk3_
}catch(Exception e){ 5/z/>D;
e.printStackTrace(); =nHgDrA_
} finally{ I++. ee
try{ 29q _BR *:
if(ps!=null) { ^G-@06 /!
ps.clearParameters(); 9~YMyg(Z
ps.close(); tklH@'q
ps=null; RCLeA=/N@0
} M&
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}catch(SQLException e){} g$o&Udgs
DBUtils.closeConnection(conn); RzusNS
} H 7
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} ^/=KK:n~
public long getLast(){ C"]^Q)aJN
return lastExecuteTime; W+1^4::+
} j1HW._G
public void run(){ t );/'3|
long now = System.currentTimeMillis(); 5nVt[Puw
if ((now - lastExecuteTime) > executeSep) { FNId;
//System.out.print("lastExecuteTime:"+lastExecuteTime); wn)W
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//System.out.print(" now:"+now+"\n"); c_l"I9M#r
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); RY*U"G0#w
lastExecuteTime=now; F1Bq$*'N$w
executeUpdate(); w:l
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} ~.lPEA %%
else{ Q.c\/&
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Y:)e(c"A
} J!7MZLb
} b*Q&CL
} R_S.tT!
//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 `x%>8/
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类写好了,下面是在JSP中如下调用。 yJe>JK~)
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<% %C_HXr@
CountBean cb=new CountBean(); VTHH&$ZNq
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); n>U5R_T
CountCache.add(cb); z,%$+)K
out.print(CountCache.list.size()+"<br>"); 2SR: FUV/
CountControl c=new CountControl(); d4z/5Oa
c.run(); X+]G-
out.print(CountCache.list.size()+"<br>"); 3%=~)7cF
%>