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: {>+$u"*
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CountBean.java Y4{`?UM&h
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/* yr=r?h}
* CountData.java $<aBawLZO
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* Created on 2007年1月1日, 下午4:44 /C(L(X
* xJ"KR:CD>
* To change this template, choose Tools | Options and locate the template under {[s<\<~B*
* the Source Creation and Management node. Right-click the template and choose cYp}$
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package com.tot.count; @"~\[z5
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/** lyi}q"Kn*;
* !e7vc[N
* @author %b*%'#iK
*/ JJ+<?CeHD
public class CountBean { [-CG&l2?L
private String countType; I#Bz
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int countId; g@U#Y#b@"
/** Creates a new instance of CountData */ o}%fs
*
public CountBean() {} `j(+Y
public void setCountType(String countTypes){ T2->
this.countType=countTypes; asF-mf;D
} <G&v
public void setCountId(int countIds){ 869`jA&7"
this.countId=countIds; c !;wp,c
} x:bYd\
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public String getCountType(){ 3Yf$WE8#l
return countType; gON6jnDO
} GmHsO/
public int getCountId(){ O-B3@qQ. h
return countId; =&p bh
} G8&'*7Bb
} )s8r(.W
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CountCache.java ((5zwD
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/* 7*5ctc!dG
* CountCache.java ]lo1Kw
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* Created on 2007年1月1日, 下午5:01 j~8+,:
* Qnw$=L:
* To change this template, choose Tools | Options and locate the template under ~3%3{aa
* the Source Creation and Management node. Right-click the template and choose U\
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* Open. You can then make changes to the template in the Source Editor. HUghl2L.<
*/ "5YdmBy
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package com.tot.count; t#q>U%!
import java.util.*; Ocb2XEF
/** w*
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* c]]F`B
* @author ZX0c_Mk=
*/
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public class CountCache { 3dbf!
public static LinkedList list=new LinkedList(); VZ,T`8"
/** Creates a new instance of CountCache */ &8pXkD#A
public CountCache() {} 3/AUV%+
public static void add(CountBean cb){ .$k"+E
if(cb!=null){ v<SEGv-
list.add(cb); IBqY$K+l
} k$c
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} gctaarB&
} Cm4*sN.&)
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CountControl.java F[u%t34'
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/* V9VP"kD
* CountThread.java x.yL'J\)
* 6:,^CI|@t
* Created on 2007年1月1日, 下午4:57 2{CSH_"Z7
* R]Oy4U,f
* To change this template, choose Tools | Options and locate the template under W'jXIO
* the Source Creation and Management node. Right-click the template and choose ETOc4hMO
* Open. You can then make changes to the template in the Source Editor. [!le 9aNg
*/ jE#8&P~
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package com.tot.count; wb[(_@eZ
import tot.db.DBUtils; X W)A~wPBs
import java.sql.*; =5`@:!t7
/** ~Hs{(7
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* @author gp)ds^
*/ _p&$X
public class CountControl{ ;N\?]{ L
private static long lastExecuteTime=0;//上次更新时间 62jA
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 wDO5Zew!
/** Creates a new instance of CountThread */ q?L(V+X
public CountControl() {} #+
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public synchronized void executeUpdate(){ ~N9-an
Connection conn=null; { 9 ".o,
PreparedStatement ps=null; F29AjW86
try{ 1%"`
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conn = DBUtils.getConnection(); _zh5KP[{
conn.setAutoCommit(false); ku?_/-ko]
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ]e.+u
for(int i=0;i<CountCache.list.size();i++){ md"%S-a_dT
CountBean cb=(CountBean)CountCache.list.getFirst(); 5@$4.BGcF
CountCache.list.removeFirst(); h*UUtLi%WU
ps.setInt(1, cb.getCountId()); P;%QA+%7
ps.executeUpdate();⑴ Hz8`)cv`
//ps.addBatch();⑵ f'O vG@
} r6JkoPMh
//int [] counts = ps.executeBatch();⑶ pXv[]v
conn.commit(); P@YL.'KU)
}catch(Exception e){ +
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e.printStackTrace(); v{ n}%akc
} finally{ %>2t=)T
try{ ?MM3LA! <
if(ps!=null) { %wW5)Y I
ps.clearParameters(); AnY)T8w
ps.close(); /zf>>O`
ps=null; TEyx((SK
} }G+A_HF ^
}catch(SQLException e){} 5Kj4!Ai
DBUtils.closeConnection(conn); ,,@`l\Pgd
} ATM:As:<@
} ^~qs-.?
public long getLast(){ +[/47uFbI
return lastExecuteTime; Lc<xgN+cJ
} /dt!J
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public void run(){ L59oh
long now = System.currentTimeMillis(); *\KvcRMGUa
if ((now - lastExecuteTime) > executeSep) { b',bi.FH
//System.out.print("lastExecuteTime:"+lastExecuteTime); b0Ov+ )7#
//System.out.print(" now:"+now+"\n"); $af}+:'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); rJZs
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lastExecuteTime=now; ZT8Ji?_n
executeUpdate(); Lzx$"R-
} 'S7@+kJ
else{ \t# 9zn>
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); G.nftp(*}
} 5w)^~#'
} h5rP]dbhXU
} R.IUBw5;/
//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 J xm9@,
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类写好了,下面是在JSP中如下调用。 NcBe|qxQ
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<% yI.H4Dl<
CountBean cb=new CountBean(); A;-z#R#V5
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); q'F_j"
CountCache.add(cb); KV}U{s+U8
out.print(CountCache.list.size()+"<br>"); 19 wqDIE0
CountControl c=new CountControl(); c4>sE[]
c.run(); .xkV#ol
out.print(CountCache.list.size()+"<br>"); KHecc/,,S
%>