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: y-cRqIM
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CountBean.java ;E l"dqH
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/* O(!J^J3_z
* CountData.java ?5K.#>{
* gG1%.q
* Created on 2007年1月1日, 下午4:44 2P`hdg
* sg;Gk/]
* To change this template, choose Tools | Options and locate the template under B=%cXW,
* the Source Creation and Management node. Right-click the template and choose U;Se'*5xv
* Open. You can then make changes to the template in the Source Editor. wA|m/SZx
*/ 7G.IGXK$
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package com.tot.count; \9geDX9A
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/** iK#5HW{
* (5]<t&M
* @author (/1 4)"Sk
*/ UpL?6)
public class CountBean { tu#VZAPW@
private String countType; %k_R;/fjW
int countId; 6AKH0t|4
/** Creates a new instance of CountData */ kIWQ
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public CountBean() {} 8`Q8Mct$<
public void setCountType(String countTypes){ &s->,-,
this.countType=countTypes; 8fKt6T
} |GM?4'2M.
public void setCountId(int countIds){ |G&<@8O
this.countId=countIds; x* *]@v"g
} GKu@8Ol-wu
public String getCountType(){ }OZ%U2PU
return countType; 75v 5/5zRn
} @(Wx(3JR?}
public int getCountId(){ (zIP@ H
return countId; [wWip1OR
} jq
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} \`}Rdr!p%
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CountCache.java RMUR@o5N
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/* mRZC98$ @r
* CountCache.java B!0o6)u'
* 6+u}'mSj8
* Created on 2007年1月1日, 下午5:01 srXGe`VL
* DygMavA.
* To change this template, choose Tools | Options and locate the template under t}>6"^}U
* the Source Creation and Management node. Right-click the template and choose c?A(C#~
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* Open. You can then make changes to the template in the Source Editor. ,X25 -OFZ
*/ 6d& dB
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package com.tot.count; U\a.'K50F
import java.util.*; pp@Jndlg
/** [* ,k
*
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* @author f4YcZyBGv
*/ W+36"?*k3
public class CountCache { smvIU0:K
public static LinkedList list=new LinkedList(); )#n0~7
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/** Creates a new instance of CountCache */ Vp{! Ft8>
public CountCache() {} 7ZarXv
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public static void add(CountBean cb){ by!1L1[JTt
if(cb!=null){ iU"jV*P]
list.add(cb); >Eg/ir0
} c]LE9<G
} >
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} ^kJ(bBY
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CountControl.java 0t[|3A~Q
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/* n6D9f~8"
* CountThread.java Y'7f"W
* T n.Cj5
* Created on 2007年1月1日, 下午4:57 e/hA>
* |s[kY
* To change this template, choose Tools | Options and locate the template under Gu[G_^>
* the Source Creation and Management node. Right-click the template and choose ,l/~epx4v)
* Open. You can then make changes to the template in the Source Editor. 0?OTa<c
*/ "P.H
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package com.tot.count; 8CCd6)cG
import tot.db.DBUtils; QJiU"1
import java.sql.*; hM$K?t
/** =v^LShD2^
* _RI`I}&9Z
* @author Age
*/ "Kky|(EQ$$
public class CountControl{ I~Y1DP)R
private static long lastExecuteTime=0;//上次更新时间 tgmG#b*
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 lh^-L+G:Ok
/** Creates a new instance of CountThread */ (ndXz
public CountControl() {} yF2|w=!
public synchronized void executeUpdate(){ `! ~~Wf'
Connection conn=null; FvpaU\D
PreparedStatement ps=null; Itq248+Ci
try{ (=#[om(A
conn = DBUtils.getConnection(); F<FNZQ@<U
conn.setAutoCommit(false); D<=x<.
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 1,UeVw/
for(int i=0;i<CountCache.list.size();i++){ @c3GJ'"X
CountBean cb=(CountBean)CountCache.list.getFirst(); fKEZlrw
CountCache.list.removeFirst(); 7G6XK
ps.setInt(1, cb.getCountId()); }U <T>0
ps.executeUpdate();⑴ NQBa+N
//ps.addBatch();⑵ q8&2M
} >
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//int [] counts = ps.executeBatch();⑶ Pn?Ujjv
conn.commit(); K>%}m,
}catch(Exception e){ tYb8a
e.printStackTrace(); M"XILNV-~
} finally{ Ek' ~i
try{ vbFi#|EU
if(ps!=null) { YY{0WWua
ps.clearParameters(); ^eF%4DUC;
ps.close(); $H\[yg>4
ps=null; z"7I5N
} Q=B>Q
}catch(SQLException e){} GjVq"S
DBUtils.closeConnection(conn); g2?kC^=z=
} ~!V5Ug_2
} KMs[/|HX\
public long getLast(){ p2m@0ou
return lastExecuteTime; eXs^YPi
} \!-IY
public void run(){ r'|V z*/h
long now = System.currentTimeMillis(); [p& n]T
if ((now - lastExecuteTime) > executeSep) { ?=u/&3Cw
//System.out.print("lastExecuteTime:"+lastExecuteTime); 'gBGZ?^N!U
//System.out.print(" now:"+now+"\n"); 31VDlcnE
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); pJg'$iR!/
lastExecuteTime=now; WFr;z*
executeUpdate(); +,;"?j6<p
} \,n|V3#G
else{ Bqcih$`BVU
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ;`")3~M3*
} p :v'"A}
} ;+-@AYl
} kdgU1T@y.
//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 m8j Q~OS
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类写好了,下面是在JSP中如下调用。 ,(&p"O":
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<% |2L|Zp&
CountBean cb=new CountBean(); 9#;GG3
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); pA%}CmrMq
CountCache.add(cb); wo#,c(
out.print(CountCache.list.size()+"<br>"); z`Jcpt
CountControl c=new CountControl(); c*m7'\
c.run(); $a@T:zfe
out.print(CountCache.list.size()+"<br>"); }]<Ghns
%>