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: `-l6S
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CountBean.java An"</;HU
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/* zN@}
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* CountData.java 7Kal"Ew
* 0F|AA"mMT
* Created on 2007年1月1日, 下午4:44 !~&R"2/
* ~ZhraSI)G
* To change this template, choose Tools | Options and locate the template under hKjt'N:~ZY
* the Source Creation and Management node. Right-click the template and choose s6zNV4
* Open. You can then make changes to the template in the Source Editor. "a"]o
*/ -VTkG]{`Ir
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package com.tot.count; >wBJy4:
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/** (?{MEwHG
* Q[I=T&
* @author j|%HIF25
*/ ); dT_
public class CountBean { b e-~\ @
private String countType; jvFTR'R)=
int countId; R_7 d@FQ1
/** Creates a new instance of CountData */ vIwCJN1C
public CountBean() {} :1^R9yWA4
public void setCountType(String countTypes){ A"D,Kg
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this.countType=countTypes; ?)X,0P'
} )'%$V%9
public void setCountId(int countIds){ [4C:r!
this.countId=countIds; #K Xa&C
} ;b(p=\i
public String getCountType(){ ,%Up0Rr,
return countType; MP 2~;T}~
} "7V2lu
public int getCountId(){ ~-m "
return countId; \z7SkZt,GT
} rT5Ycm@
} <-S%kA8
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CountCache.java 4^Q:
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/* !PJ 6%"
* CountCache.java 78OIUNm`
* !\L/[:n
* Created on 2007年1月1日, 下午5:01 `Ru3L#@
* nMvKTH
* To change this template, choose Tools | Options and locate the template under {0^&SI"5`E
* the Source Creation and Management node. Right-click the template and choose ?Poq2
* Open. You can then make changes to the template in the Source Editor. ehG/zVgn
*/ Ve!fU
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package com.tot.count; sZm$|T0
import java.util.*; i21Gw41p:
/** e `,ds~
* F^LZeF[#t
* @author FMkzrs
*/ -3lb@ 6I6
public class CountCache { 5
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public static LinkedList list=new LinkedList(); *9c!^$V
/** Creates a new instance of CountCache */ Fa_VKAq
public CountCache() {} Y> Wu
public static void add(CountBean cb){ {=-\|(Bx
if(cb!=null){ uDSxTz{
list.add(cb); wqW0v\
} Gkv{~?95
} )}'U`'q
} X>.
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CountControl.java R@#G>4
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/* QtqfG{
* CountThread.java 70mpSD3
* Cp]"1%M,
* Created on 2007年1月1日, 下午4:57 jDN ]3Y`
* fpN-
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* To change this template, choose Tools | Options and locate the template under Ttc[Q]Ri
* the Source Creation and Management node. Right-click the template and choose +_xOLiu
* Open. You can then make changes to the template in the Source Editor. Yx inE`u~
*/ !i%"7tQ3$
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package com.tot.count; e^Ky<*Y
import tot.db.DBUtils; z)=+ F]
import java.sql.*; XNb ZNaAd
/** ,qrQ"r9
* GSQ/NYK
* @author 7ei|XfR
*/ 3^~KB'RZ
public class CountControl{ xOHgp=#D
private static long lastExecuteTime=0;//上次更新时间 [mr9(m[F
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 j$Je6zq0x
/** Creates a new instance of CountThread */ p6XtTx
public CountControl() {} ]a3iEA2 (
public synchronized void executeUpdate(){ MqA`yvQm
Connection conn=null; P7f,OY<@%o
PreparedStatement ps=null; f5==";eP
try{ ?k|H3;\
conn = DBUtils.getConnection(); FSbHn{@
conn.setAutoCommit(false); pdEiqLhH
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); _ _>.,gL7
for(int i=0;i<CountCache.list.size();i++){ 9bq<GC'eX8
CountBean cb=(CountBean)CountCache.list.getFirst(); eDZ8w
CountCache.list.removeFirst(); 0W()lQ
ps.setInt(1, cb.getCountId()); Q;J`Q wkH
ps.executeUpdate();⑴ 6q6FB
//ps.addBatch();⑵ %F*|;o7 s
} @b3#X@e}
//int [] counts = ps.executeBatch();⑶ }Lw>I94e
conn.commit(); okFvn;
}catch(Exception e){ T'aec]u
e.printStackTrace(); @(i!YL
} finally{ H7kPM[
try{ A?T<",bO
if(ps!=null) { ?kz+R'
ps.clearParameters(); ^p/Ob'!
ps.close(); !!nuAQ"E[
ps=null; h}Wdh1.M3
} 1uk0d`JL
}catch(SQLException e){} 3o|I[!2.
DBUtils.closeConnection(conn); ,mL
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} k%op>
&
} <JwX_\?ln
public long getLast(){ !;!~n`
return lastExecuteTime; b2b75}_A
} `g1iCF
public void run(){ Y05P'Q
long now = System.currentTimeMillis(); }/,CbKi,+
if ((now - lastExecuteTime) > executeSep) { *VkgQ`c
//System.out.print("lastExecuteTime:"+lastExecuteTime); ' 2-oh
//System.out.print(" now:"+now+"\n"); OcSEo7W
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Q!FLR>8
lastExecuteTime=now; DK&h
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executeUpdate(); %&\ jOq~
} Lh-`OmO0>F
else{ Zf>^4_x3P
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); (?b@b[D~4
} A;u" <KG?
} 9r2IuS0
} $.489x+'Z
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 xT)psM'CL
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类写好了,下面是在JSP中如下调用。 X}6#II
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<% [!VOw@uz
CountBean cb=new CountBean(); U#o'H @
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 6R29$D|HFO
CountCache.add(cb); 7.+#zyF
out.print(CountCache.list.size()+"<br>"); 9=/N|m8.
CountControl c=new CountControl(); [;b=A
c.run(); kV Rn`n0
out.print(CountCache.list.size()+"<br>"); /+3a n9h
%>