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: gk1I1)p
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CountBean.java ]9pK^<
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/* f4@>7K]9TA
* CountData.java /n"Ib)M
* >T'^&l(:
* Created on 2007年1月1日, 下午4:44 CuR.a
* Wz`MEyj
* To change this template, choose Tools | Options and locate the template under Hw-,sze j"
* the Source Creation and Management node. Right-click the template and choose |W[BqQIf
* Open. You can then make changes to the template in the Source Editor. f,wB.MN
*/ \'q 9,tP
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package com.tot.count; {=pRU_-^
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/** z^;*&J
* :7
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* @author \#?n'qyj
*/ no~hYyW2
public class CountBean { tsaf|xe
private String countType; #T &z`
int countId; n}Pz:
/** Creates a new instance of CountData */ T:p,!?kc7
public CountBean() {} K; ,2ag
public void setCountType(String countTypes){ 6`Zx\bPDm
this.countType=countTypes; v1*Lf/
} _BHR ?I[w
public void setCountId(int countIds){ i"V2=jTeBv
this.countId=countIds; !#wd~: H
} E2+x?Sc+
public String getCountType(){ A2LqBirkl
return countType; \3a(8Em
}
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public int getCountId(){ (\S/
return countId; F0
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} O4H %x
} vu-QyPnS|w
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CountCache.java oNH&VHjU
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/* 8#b>4Dx
* CountCache.java sz}YXR=m
* [+dOgyK
* Created on 2007年1月1日, 下午5:01 I[E/)R{\
* B]jN~CO?
* To change this template, choose Tools | Options and locate the template under Sg;c |u
* the Source Creation and Management node. Right-click the template and choose lt%bGjk
* Open. You can then make changes to the template in the Source Editor. KFd !wZ@e
*/ >5G2!Ns'
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package com.tot.count; iF:`rIC
import java.util.*; `uK_}Vy_
/**
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* iX
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* @author Eo)w f=rE9
*/ 2' fg
public class CountCache { rWk4)+Tk
public static LinkedList list=new LinkedList(); @w:6m&KL9
/** Creates a new instance of CountCache */ NgH"jg-
public CountCache() {} *p)1c_
public static void add(CountBean cb){ p<%76H
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if(cb!=null){ <~ E'% 60;
list.add(cb); m E<n=g=
} m<]b]FQ
} ^}nz^+R
} ra#s!m1
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CountControl.java ~bL^&o(W
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/* G+Vlaa/7
* CountThread.java O%:EPdoU
* 1~X~"M
* Created on 2007年1月1日, 下午4:57 )<W6cDx'H+
* F=}-ngx8&
* To change this template, choose Tools | Options and locate the template under nU]4)t_o\
* the Source Creation and Management node. Right-click the template and choose
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* Open. You can then make changes to the template in the Source Editor. eq>E<X#<
*/ r[2N;U
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package com.tot.count; X2ShxD|
import tot.db.DBUtils; 7|=*z
import java.sql.*; JUBihw4
/** i^hgs`hvU
* eO<:X|9T
* @author Ya$JX(aUe
*/ K.CwtUt`54
public class CountControl{ l+$e|F
private static long lastExecuteTime=0;//上次更新时间 $'M:H_T
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 .^]=h#[e
/** Creates a new instance of CountThread */ >C|/%$kk:f
public CountControl() {} WHh=hts\
public synchronized void executeUpdate(){ +;nADl+Q
Connection conn=null; n|,kL!++.
PreparedStatement ps=null; cZnB 2T?
try{ xxnMvL;
conn = DBUtils.getConnection(); $O|J8; "v
conn.setAutoCommit(false); Rxe
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 6.fahg?E
for(int i=0;i<CountCache.list.size();i++){ +{* @36A5A
CountBean cb=(CountBean)CountCache.list.getFirst(); Q=hf,/N
CountCache.list.removeFirst(); xv!
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ps.setInt(1, cb.getCountId()); 3W*O%9t7
ps.executeUpdate();⑴ # f~,8<K
//ps.addBatch();⑵ G(piq4D
} UMe@[E=
//int [] counts = ps.executeBatch();⑶ ;1`NsYI2
conn.commit(); /W !A^
}catch(Exception e){ jtWI@04o09
e.printStackTrace(); w`~j(G4N
} finally{ x @EEMO1_"
try{ G[V?#7.
if(ps!=null) { \qPgQsy4
ps.clearParameters(); ;jb+x5t
ps.close(); 'IrwlS
ps=null; \]AsL&
} 7X| M\WUq
}catch(SQLException e){} }^J&D=J5V
DBUtils.closeConnection(conn); UYu 54`'kg
} -:txmMT
} nU Oy-c
public long getLast(){ eit>4xMu
return lastExecuteTime; MYqxkhcLH1
} *.ffyBI*~
public void run(){ ^FLuhLS\*
long now = System.currentTimeMillis(); 7 R1;'/;
if ((now - lastExecuteTime) > executeSep) { Z4#lZS`'A
//System.out.print("lastExecuteTime:"+lastExecuteTime); /uSEG<D
//System.out.print(" now:"+now+"\n"); ,"/<N*vh
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); oL' :07_
lastExecuteTime=now; gd9ZlHo'Id
executeUpdate(); pH&Q]u;O
} pf.T{/%
else{ G6X
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); m9^?p
}
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} ^0 t81,`
} E.Hw|y0_(|
//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 Q}!U4!{i|p
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类写好了,下面是在JSP中如下调用。 +nKxSjqI
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<% Gq5)>'D?
CountBean cb=new CountBean(); >M7e'}0;
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); u(KeS`
CountCache.add(cb); i,/|H]Mzr
out.print(CountCache.list.size()+"<br>"); KZV$rJ%G
CountControl c=new CountControl(); cm]D"GFLY
c.run(); l7 D/]&
out.print(CountCache.list.size()+"<br>"); ?9q{b\=l
%>