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: nG?Z* n
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CountBean.java =eDC{/K
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/* @(N}
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* CountData.java I*a.!/$)
* -y3[\zNe
* Created on 2007年1月1日, 下午4:44 2lN0Sf@
* *&h]PhY
* To change this template, choose Tools | Options and locate the template under ft0d5n!ui4
* the Source Creation and Management node. Right-click the template and choose cf"!U+x
* Open. You can then make changes to the template in the Source Editor. ,Tx38
*/ ~-%z:Re'_
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package com.tot.count; IC$"\7
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/** gOE?
* o~4kJW#
* @author /1.Z=@ 7
*/ TC=>De2;
public class CountBean {
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private String countType; V! TGFo}
int countId; opzlh@R
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/** Creates a new instance of CountData */ _o+OkvhU
public CountBean() {} 8)Vl2z
public void setCountType(String countTypes){ W4(
this.countType=countTypes; HB.:/5\
} **1=|aa:
public void setCountId(int countIds){ A5%Now;.cf
this.countId=countIds; Dd,
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} XI`s M~'
public String getCountType(){ B_8JwMJu3
return countType;
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} P~x4h{~Gd
public int getCountId(){ Zk|PQfi+
return countId; MA%g-}
} H3iYE~^#
} KMl3`+i
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CountCache.java t)O]0)
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/* 3{ea~G)[9
* CountCache.java I-kK^_0mV<
* fti0Tz'
* Created on 2007年1月1日, 下午5:01 }y(cv}8Y
* KxFA@3
* To change this template, choose Tools | Options and locate the template under c2s73iz
* the Source Creation and Management node. Right-click the template and choose o(D_ /]'8
* Open. You can then make changes to the template in the Source Editor. 20Jlf?
*/ L$, Kdpj
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package com.tot.count; W~l.feW$i
import java.util.*; GQjU="+
/** m>!o
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* c@j3L23B
* @author .~^A!t
*/ ;{e'q?Y
public class CountCache { tm_\(
public static LinkedList list=new LinkedList(); ?fc<3q"
/** Creates a new instance of CountCache */ c%
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public CountCache() {} 3lS1WA
public static void add(CountBean cb){ ;xai JJK{
if(cb!=null){ FysIN~
list.add(cb); Gsm.a
} `:0Auw9h
} C8(0|XX
} "0z4mQ}>N
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CountControl.java wjOJn]
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/* e%7#e%1s
* CountThread.java HA&hu/mw_
* s4=EyBI
* Created on 2007年1月1日, 下午4:57 =#{q#COK$
* D_`~$QB`,
* To change this template, choose Tools | Options and locate the template under 7o7FW=^
* the Source Creation and Management node. Right-click the template and choose RH$YM
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* Open. You can then make changes to the template in the Source Editor. .8[uEQ_L
*/ kD((1v*D$
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package com.tot.count; 6J-=6t|
import tot.db.DBUtils; yio8BcXH54
import java.sql.*; (d .M} G
/** ?+{_x^
* G6\`Iy68/v
* @author f&Juq8s_0
*/ lXVh`+X/l
public class CountControl{ M%$-c3x
private static long lastExecuteTime=0;//上次更新时间 `C^0YGO%
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 PT4iy<
/** Creates a new instance of CountThread */ yRp&pUtb
public CountControl() {} _0iV6Bj
public synchronized void executeUpdate(){ <e@4;Z(h04
Connection conn=null; xxC2 h3
PreparedStatement ps=null; p@@*F+
try{ .lSoC`HE
conn = DBUtils.getConnection(); YYe=E,q
conn.setAutoCommit(false); eZg>]<L
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); |h.@Xy
for(int i=0;i<CountCache.list.size();i++){ w,<n5dMv
CountBean cb=(CountBean)CountCache.list.getFirst(); , $cpm=1
CountCache.list.removeFirst(); %T}*DC$&S
ps.setInt(1, cb.getCountId()); :{KpnJvd
ps.executeUpdate();⑴ og4mLoLA
//ps.addBatch();⑵ L /N%ft]!T
} #3FsK
//int [] counts = ps.executeBatch();⑶ O6\c1ha
conn.commit(); sP>-k7K.
}catch(Exception e){ v*OT[l7
e.printStackTrace(); b
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} finally{ rWN%j)#+
try{ *qr>x8OGp
if(ps!=null) { *c(YlfeZ#
ps.clearParameters(); $+U6c~^^
ps.close(); <Iil*\SC
ps=null; J7kqyo"
} pMf
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}catch(SQLException e){} {?}^HW9{
DBUtils.closeConnection(conn); 5'|W(yR}
} OgzKX>N`A
} ;):E 8;B)
public long getLast(){ Xhpcu1nA
return lastExecuteTime; ~L_1&q^4!i
} aR)w~s\6
public void run(){ ( De>k8
long now = System.currentTimeMillis(); 3/,}&SX
if ((now - lastExecuteTime) > executeSep) { #w!ewC vt
//System.out.print("lastExecuteTime:"+lastExecuteTime); *}>)E]O@
//System.out.print(" now:"+now+"\n"); =8Z-ORW51
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); jK{qw
lastExecuteTime=now; }E&:
executeUpdate(); Q-yNw0V}F
} =9:gW5F69
else{ jq_ i&~S
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 8RcLs1n/
} J(9{P/
} 2~yj
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} P<LmCYm
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 CFu^i|7o
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类写好了,下面是在JSP中如下调用。 sH%Ts@Pl
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<% _C,9c7K4
CountBean cb=new CountBean(); TRE D_6
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); P!XO8X 1F
CountCache.add(cb); +$#h6V
out.print(CountCache.list.size()+"<br>"); Q5Epq
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CountControl c=new CountControl(); -\25&m!+
c.run(); sDBwD%sb
out.print(CountCache.list.size()+"<br>"); xO4""/n
%>