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: L u1pxL
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CountBean.java <aQ5chf7
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/* _2w8S\
* CountData.java 3f(tb%pa5
* N)4R.}
* Created on 2007年1月1日, 下午4:44 l<:\w.Gl
* m(IyW734I
* To change this template, choose Tools | Options and locate the template under f0
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* the Source Creation and Management node. Right-click the template and choose J$i.^|hE/
* Open. You can then make changes to the template in the Source Editor. GezMqt;2
*/ ^/~C\
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package com.tot.count; GQDW}b8
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/** aUq2$lw1
* Dq+S'x~>
* @author Rw)=<XV)6
*/ ( e4#9
public class CountBean { Y|E rVf4
private String countType; wY"BPl]b
int countId; Y6m:d&p=}
/** Creates a new instance of CountData */ /xCX. C
public CountBean() {} P DwBSj
public void setCountType(String countTypes){ jmF)iDvjuZ
this.countType=countTypes; PxA
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} +#9 4X)*
public void setCountId(int countIds){ E_\V^
this.countId=countIds; w9675D+
} V/BU(`~i
public String getCountType(){ pj Md
return countType; }WHq?
} iw{^nSD
public int getCountId(){ Bo8NY!
return countId; ef2)k4)"
} eIQ@){lJ-]
} eU\XAN#@
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CountCache.java +*wr=9>
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/* yz=aJ
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* CountCache.java 8khIy-9-'
* -PTfsQk
* Created on 2007年1月1日, 下午5:01 }^2'@y!(
* N v6=[_D
* To change this template, choose Tools | Options and locate the template under U#|6n ,
* the Source Creation and Management node. Right-click the template and choose B7PdavO#
* Open. You can then make changes to the template in the Source Editor. US\h,J\Ju
*/ K94bM5O 1
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package com.tot.count; v1p^="IHI
import java.util.*; "b) hj?
/** &]pY~zVc
* *W2o$_Hs
* @author ~ 1~|/WG
*/ `eeA,K_
public class CountCache { Z9eP(ip
public static LinkedList list=new LinkedList(); 1Cw
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/** Creates a new instance of CountCache */ xqfIm%9i}
public CountCache() {} A2SDEVU
public static void add(CountBean cb){ L~C:1VG5
if(cb!=null){ -_= m j
list.add(cb); :QC |N@C
} 8vQR'<,
} a\&g;n8jA
} w-3Lw<
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CountControl.java AWi+xo|
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/* )KOIf{
* CountThread.java }i J$&CJ
* tVh"C%Vkr
* Created on 2007年1月1日, 下午4:57 ] !n3j=*
* Pbt7T
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* To change this template, choose Tools | Options and locate the template under IyAD>Q^
* the Source Creation and Management node. Right-click the template and choose @M"(
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* Open. You can then make changes to the template in the Source Editor. XSGBC:U)l
*/ TX;)}\
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package com.tot.count; t%StBq(q
import tot.db.DBUtils; qfjUJ/
import java.sql.*; $W%-Mm
/** W}#n.c4+
* ;=WwJ Np~
* @author '4CD
}
*/ KDb`g}1Q
public class CountControl{ 0{
private static long lastExecuteTime=0;//上次更新时间 3-'3w ,
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Jhfw$ DF
/** Creates a new instance of CountThread */ E6z&pM8<8
public CountControl() {} .y lvJ$
public synchronized void executeUpdate(){ eD7qc1*G
Connection conn=null; mtdy@=?1Y
PreparedStatement ps=null; ?!O4ia3nFk
try{ @8$z2
conn = DBUtils.getConnection(); u60RuP&
conn.setAutoCommit(false);
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); L|B! ]}
for(int i=0;i<CountCache.list.size();i++){ zrf
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CountBean cb=(CountBean)CountCache.list.getFirst(); _!_1=|[
CountCache.list.removeFirst(); =2}V=E/85
ps.setInt(1, cb.getCountId()); zRbY]dW
ps.executeUpdate();⑴ z#1"0Ks&P
//ps.addBatch();⑵ 20}w.V
} sPXjU5uq#
//int [] counts = ps.executeBatch();⑶ }9&dY!h +
conn.commit(); nxNHf3
}catch(Exception e){ 1}Y3|QxF
e.printStackTrace(); %0 i)l|
} finally{ /4@
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try{ z:Z-2WV2o
if(ps!=null) { SlwQ_F"4L
ps.clearParameters(); JW)f'r_f
ps.close(); 4c[/%e:\-
ps=null; Y6Ux*vhK
} vPc*x5w-
}catch(SQLException e){} $HtGB]
DBUtils.closeConnection(conn); 9Q!Z9n"8~)
} tzv4uD]
} _GrifGU\
public long getLast(){ :wG
)
return lastExecuteTime; kdp^{zW}
} #Ge_3^'
public void run(){ i,S1|R
long now = System.currentTimeMillis(); xaVn.&Wl
if ((now - lastExecuteTime) > executeSep) { r?!:%L
//System.out.print("lastExecuteTime:"+lastExecuteTime); BC\W`K
//System.out.print(" now:"+now+"\n"); "eqzn KT%u
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 'GT^araz
lastExecuteTime=now; '#=0q
executeUpdate(); %V+"i_{m
} :H wdXhA6
else{ EB*C;ms
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); &AWrM{e
} paLPC&G
} ZhoV,/\+
} 7mf&`.C
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//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 V )1.)XC
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类写好了,下面是在JSP中如下调用。 ,aa
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<% W)J MV
CountBean cb=new CountBean(); '5LdiSk
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 2ij&Db/
CountCache.add(cb); Dh}(B$~Oz+
out.print(CountCache.list.size()+"<br>"); ^;rjs|`K#
CountControl c=new CountControl(); j>B* 8*Ss
c.run(); 0{vH .b
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out.print(CountCache.list.size()+"<br>"); AI Kz]J0;
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