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: qc"PTv0q
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CountBean.java "] [u
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/* 4;V;8a\A
* CountData.java NEW0dF&)
* qx";G
* Created on 2007年1月1日, 下午4:44 L17{W4
* w On*QO[
* To change this template, choose Tools | Options and locate the template under 8T}Dn\f
* the Source Creation and Management node. Right-click the template and choose h)h%y)1
* Open. You can then make changes to the template in the Source Editor. 4MPR
*/ Q=h37]U+
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package com.tot.count; =i:,")W7=
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/** 4GG0jCNk
* }.N~jx0R
* @author Uc( z|
*/ sOhKMz
public class CountBean { r:--DKt
private String countType; Q9{f'B
int countId; .tA=5QY,
/** Creates a new instance of CountData */ rj/1AK
public CountBean() {} L!0}&i;u~5
public void setCountType(String countTypes){ &}!AjA)
this.countType=countTypes; SlI
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} 2U&+K2
public void setCountId(int countIds){ K:b^@>XH
this.countId=countIds; #+(@i|!ifo
} N ,nvAM
public String getCountType(){ UY^TTRrH
return countType; \:9<d@?
} VfkQc$/
public int getCountId(){ pMV ?vH
return countId; *X8Pa;x
} EL(BXJrx{
} !112u#V
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CountCache.java Xh@;4n
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/* b]g#mQ
* CountCache.java ccwz:7r
* g4&f2D5
* Created on 2007年1月1日, 下午5:01 6 jU?~
* 8f>v[SQ"
* To change this template, choose Tools | Options and locate the template under iM M s3
* the Source Creation and Management node. Right-click the template and choose cS(=wC
* Open. You can then make changes to the template in the Source Editor. ?D['>Rzu
*/ @nOuFX4
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package com.tot.count;
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import java.util.*; FZtT2Z4&i
/** L b-xc]
* N9 TM
* @author ;^cMP1SH
*/ )WsR
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public class CountCache { +2g}wH)l
public static LinkedList list=new LinkedList(); SXx4^X
/** Creates a new instance of CountCache */ qJ[wVNHh!
public CountCache() {} `.3{
public static void add(CountBean cb){ ;E0x#JUrw
if(cb!=null){ {hVc,\A
list.add(cb); : eFyd`Syw
} ~~}8D"
} /Nns3oE
} %e+{wU}w?2
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CountControl.java L~*nI d
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/* NL &![;
* CountThread.java %lGT|XrY
* OmZK~$K_
* Created on 2007年1月1日, 下午4:57 T'a&
* `a5,5}7v%`
* To change this template, choose Tools | Options and locate the template under A`1-c
* the Source Creation and Management node. Right-click the template and choose R~BFZF>:
* Open. You can then make changes to the template in the Source Editor. _7<G6q2(
*/ {EJ+
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package com.tot.count; +>Pq]{Uf1j
import tot.db.DBUtils; j-zWckT{
import java.sql.*; p~OX1RBI
/** ?dmwz4k0
* n^` `)"
* @author Y8for'
*/ ,qj M1xkL$
public class CountControl{ T;v^BVn
private static long lastExecuteTime=0;//上次更新时间 {7.uwIW.1
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 HpS1(%d"
/** Creates a new instance of CountThread */ .J?RaH{i
public CountControl() {} ik5"9b-\<
public synchronized void executeUpdate(){ I5E+=.T*ar
Connection conn=null; et<@3wyd]
PreparedStatement ps=null; ]F #0to
try{ f{U,kCv
conn = DBUtils.getConnection(); |nY+Nen7
conn.setAutoCommit(false); ~?B\+6<V
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); #J~xKyJi'
for(int i=0;i<CountCache.list.size();i++){ ;}'Z2gZB
CountBean cb=(CountBean)CountCache.list.getFirst(); U04)XfO;]
CountCache.list.removeFirst(); !,{-q)'D
ps.setInt(1, cb.getCountId()); -BH T'zq1S
ps.executeUpdate();⑴ @%!Gj{
//ps.addBatch();⑵ Y#FSU#a$<
} z8
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//int [] counts = ps.executeBatch();⑶ y1#QP3'Z1
conn.commit(); 2[Xe:)d
}catch(Exception e){ 06I(01M1
e.printStackTrace(); %>t4ib_8
} finally{ *_"lXcG.
try{ 4F+G;'JV
if(ps!=null) { i}@5<&J
ps.clearParameters(); =Ds&ArG
ps.close(); FYH^axpp
ps=null; ;Bat--K7+
} [Vj|fy4
}catch(SQLException e){} SDO~g ~NTp
DBUtils.closeConnection(conn); LG'1^W{a
} aZ}z/.b]
} (, $Lp0mB7
public long getLast(){ n6{nx[%7N7
return lastExecuteTime; B RtT 7
} xLw[
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public void run(){ eNrwkV^
long now = System.currentTimeMillis(); rLcXo%w
if ((now - lastExecuteTime) > executeSep) { ZWx4/G
//System.out.print("lastExecuteTime:"+lastExecuteTime); @}{Fw;,(7n
//System.out.print(" now:"+now+"\n"); 8KWhXF
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |`Be(
lastExecuteTime=now; qG0gc\C}
executeUpdate(); c3Zwp%
} RY*yj&?w[
else{ e r"gPW
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); `3.bux~
} 2G$-:4B
} 9HAK
} ~TjTd
//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 `!.c_%m2
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类写好了,下面是在JSP中如下调用。 s"l ^v5
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<% n yNHjn
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CountBean cb=new CountBean(); jyC>~}?
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); hcQv!!Q"k$
CountCache.add(cb); CN7qqd
out.print(CountCache.list.size()+"<br>"); S.^x)5/,,T
CountControl c=new CountControl(); uU1q?|4
c.run(); BF
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out.print(CountCache.list.size()+"<br>"); >2tosxH M
%>