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: <d5@CA+M
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CountBean.java ev9;Ld
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/* ^:`oP"%-T
* CountData.java ~12_D'8D[
* "`pNH'
* Created on 2007年1月1日, 下午4:44 S]}}A
* n.*3,4.]
* To change this template, choose Tools | Options and locate the template under PU W[e%
* the Source Creation and Management node. Right-click the template and choose U^MuZ
* Open. You can then make changes to the template in the Source Editor. v=!YfAn
*/ ?w-1:NWjt
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package com.tot.count; bW53" `X
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/** MDJc[am
* (8.{+8o
* @author j~bAbOX12
*/ iOX Z]Xj5
public class CountBean { i[\w%(83Fi
private String countType; r'/\HWNP
int countId; Hkdf $$\
/** Creates a new instance of CountData */ dL-i)F
public CountBean() {} 6^)rv-L~5y
public void setCountType(String countTypes){ 5F2_xH$5
this.countType=countTypes; *ZaaO^!
} GcT;e5D
public void setCountId(int countIds){ SxJ$b
this.countId=countIds; l3.
} iv*V#J>
public String getCountType(){ .}q]`<]ze
return countType; ;f:gX`"\
} ^i+[m
public int getCountId(){ ]jyM@
return countId; @Br
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} u:@U
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} Y25^]ON*\^
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CountCache.java ?]c+j1i
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/* \q "N/$5{f
* CountCache.java <:&de8bT
* =. *98
* Created on 2007年1月1日, 下午5:01 t6+YXjXK
* B:<
]Hl$
* To change this template, choose Tools | Options and locate the template under [:iv4>ZZ
* the Source Creation and Management node. Right-click the template and choose 3GF2eS$$P
* Open. You can then make changes to the template in the Source Editor. &SH1q_&BQ
*/ `
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package com.tot.count; rAb&I"\ZY
import java.util.*; >O#grDXb
/** 24ux
* iXFP5a>|
* @author c
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*/ & ze>X
public class CountCache { 6BocGo({
public static LinkedList list=new LinkedList(); tu0aD%C
/** Creates a new instance of CountCache */ \}5p0.=
public CountCache() {} d,0 }VaY=D
public static void add(CountBean cb){ PE"v*9k
if(cb!=null){ Ya#h'+}
list.add(cb); paW@\1Q
} :=Kx/E:1
} fuUm}N7
} @*>Sw>oet
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CountControl.java t{dSX?<nt
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/* }fZ`IOf
* CountThread.java h5"Ov,K3[
* ibpzeuUl
* Created on 2007年1月1日, 下午4:57 ,qQG;w,m
* #Yuvbb[
* To change this template, choose Tools | Options and locate the template under geM6G$V&
* the Source Creation and Management node. Right-click the template and choose RO&H5m r%@
* Open. You can then make changes to the template in the Source Editor. ^B/9{0n'
*/ 3QXjD/h
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package com.tot.count; JWv{=_2w
import tot.db.DBUtils; J~#$J&iKh
import java.sql.*; qQ0C ?
/** uuNR?1fS
* ua5?(,E`']
* @author a|4~NL
*/ C3'rtY.
public class CountControl{ R@iUCT^$
private static long lastExecuteTime=0;//上次更新时间 XL$* _c <)
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 O(z}H}Fv
/** Creates a new instance of CountThread */ $w#r"= )
public CountControl() {} #!2k<Q*5uT
public synchronized void executeUpdate(){ G8Z 4J7^
Connection conn=null; i3VW1~ .8
PreparedStatement ps=null; S'LZk9E
try{ )IL
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conn = DBUtils.getConnection(); .8WXC
conn.setAutoCommit(false); EW<kI+0D
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ObG|o1b
for(int i=0;i<CountCache.list.size();i++){ (`BSVxJH
CountBean cb=(CountBean)CountCache.list.getFirst(); Q`%R[#
CountCache.list.removeFirst(); lrWQOYf2
ps.setInt(1, cb.getCountId()); FV39QG4b4
ps.executeUpdate();⑴ 4|?{VQ
//ps.addBatch();⑵ Oakb'
} $wB^R(f@
//int [] counts = ps.executeBatch();⑶ bFS>)
conn.commit(); Bux [6O%
}catch(Exception e){ Hr<o!e{Y
e.printStackTrace(); px;/8c-
} finally{ U]|agz>
try{ E.`U`L
if(ps!=null) { n5-)/R[z
ps.clearParameters(); 9BEFr/.
ps.close(); '8 Ztj
ps=null; (ll*OVL
} ?, r~=
}catch(SQLException e){} X-LA}YH=tS
DBUtils.closeConnection(conn); 8.J(r(;>
} bx4'en#
} ~ PWSo%W8
public long getLast(){ xNK1h-t
return lastExecuteTime; i_Re*
} /u%h8!"R
public void run(){ &MZ$j46
long now = System.currentTimeMillis(); nlYR-.
if ((now - lastExecuteTime) > executeSep) { +!IQj0&'Y3
//System.out.print("lastExecuteTime:"+lastExecuteTime); @Ky> 9m{
//System.out.print(" now:"+now+"\n"); '*^yAlgtt
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); /iC;%r1L
lastExecuteTime=now; v1JS~uDz
executeUpdate(); 7dG79H
} Ys+OB*8AE
else{ iD38\XNMV
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); dy__e ^qi
} rl#vE's6.e
} / $ :j
} OLGBt
//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 2&'|Eqk
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类写好了,下面是在JSP中如下调用。 B(?Yw>Xd[
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<% u]-_<YZ'B
CountBean cb=new CountBean(); 1n5(S<T
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); @`opDu!
CountCache.add(cb); :2
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out.print(CountCache.list.size()+"<br>"); 0Sq][W=
CountControl c=new CountControl(); '>$EOg"
c.run(); X,aYK;q%z
out.print(CountCache.list.size()+"<br>"); \0l>q ,
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