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: H]YPMG<
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CountBean.java IX-ir
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/* DUa`8cE}
* CountData.java !30BZM^
* 1 [dza5
* Created on 2007年1月1日, 下午4:44 =`g+3
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* kIM* K%L}
* To change this template, choose Tools | Options and locate the template under 7Ij FSN>
* the Source Creation and Management node. Right-click the template and choose EpS"NQEe
* Open. You can then make changes to the template in the Source Editor. YwEXTy>0
*/ Z5\u9E"]
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package com.tot.count; ^cd+W?
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/** d&t|Y:,8
* }F**!%4d
* @author _aq3G9C_
*/ Q-(twh
public class CountBean { Pr/K5aJeg
private String countType; -cEjB%Neo
int countId; $--W,ov5j
/** Creates a new instance of CountData */ 4R@3jGXb8q
public CountBean() {} K6_{AuL}4
public void setCountType(String countTypes){ %J7 ;b<}To
this.countType=countTypes; H7*/
} H<g-
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public void setCountId(int countIds){ Ql!$e&A|l
this.countId=countIds; d:Wh0 y}
} |5`z;u7V
public String getCountType(){ b?qtTce
return countType; <SOC
} Fb
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public int getCountId(){ {dhG SM7
return countId; :Q"]W!kCs
} W8R@Pf
} $!ka8)
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CountCache.java nO2-fW:9]
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/* C%0 |o/Wi
* CountCache.java <e)3 j6F!
* &p`RKD
* Created on 2007年1月1日, 下午5:01 O$LvHv!
* [@_}BZk
* To change this template, choose Tools | Options and locate the template under 6O!&!
* the Source Creation and Management node. Right-click the template and choose 8E ^yHd4Y
* Open. You can then make changes to the template in the Source Editor. p'ukV(B
*/ zuwCN.
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package com.tot.count; PL[7|_%
import java.util.*; 1\TXb!OtL
/** 8ZE{GX.m2c
* T[;O K
* @author 2VA\{M
*/ ZFY t[:
public class CountCache { .{*V^[.
public static LinkedList list=new LinkedList(); 9#xcp/O
/** Creates a new instance of CountCache */ mn)kd
public CountCache() {} &U*=D8!0
public static void add(CountBean cb){ SZea[~&
if(cb!=null){ 1|Us"GQ(n
list.add(cb); ZV$qv=X
} /9QI^6&SX
} O-@*xwD
} e>=P'
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CountControl.java +K])&}Dw
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/* g,@0 ;uVq
* CountThread.java ;3-5U&Axt
* Re0ma%~LP
* Created on 2007年1月1日, 下午4:57 ECWn/4Aws
* F$N"&<[c
* To change this template, choose Tools | Options and locate the template under Wf +j/RxTi
* the Source Creation and Management node. Right-click the template and choose bO^#RVH
* Open. You can then make changes to the template in the Source Editor. ]4ya$%A
*/ .'saUcVg:
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package com.tot.count; RU|{'zC\v
import tot.db.DBUtils; i"p)%q~ z
import java.sql.*; TLU^ad#9E
/** _p"nR
* DP6 M4
* @author 8A~5@
*/ %+ynrg-
public class CountControl{ _pnJ/YE
private static long lastExecuteTime=0;//上次更新时间 J]^)vxm3
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Ph'*s{
/** Creates a new instance of CountThread */ DBI[OG9
public CountControl() {} `BG{\3>
public synchronized void executeUpdate(){ qM~ev E$%
Connection conn=null; SxdH%agM
PreparedStatement ps=null; _=Ed>2M)no
try{ NjIe2)}'
conn = DBUtils.getConnection(); Z_.Eale^
conn.setAutoCommit(false); , |,DXw
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); uW3`gwwlU
for(int i=0;i<CountCache.list.size();i++){ yCy4t6`e
CountBean cb=(CountBean)CountCache.list.getFirst(); 9
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CountCache.list.removeFirst(); -{dsl|Dl
ps.setInt(1, cb.getCountId()); `9}\kn-</8
ps.executeUpdate();⑴ -
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//ps.addBatch();⑵ jO)UK.H#
} &`[y] E'
//int [] counts = ps.executeBatch();⑶ *4"s,1?@BG
conn.commit(); M^JRHpTn
}catch(Exception e){ BFmd`#{l
e.printStackTrace(); ? >SC:{(
} finally{ 8M9 &CsT6
try{ fgVeB;k|
if(ps!=null) { [#S}L(
ps.clearParameters(); NHG+l)y:
ps.close(); vtM!?#
ps=null; g.ty#Z=:
} +YVnA?r?
}catch(SQLException e){} 6Lk<VpAa
DBUtils.closeConnection(conn); |r[yMI|VR
} 2UU5\
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} |!NKKvf
public long getLast(){ L
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return lastExecuteTime; _C$JO
} sS/#)/B
public void run(){ Rd7Xs
long now = System.currentTimeMillis(); ,iY/\
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if ((now - lastExecuteTime) > executeSep) { @5+ JXD
//System.out.print("lastExecuteTime:"+lastExecuteTime); ]:m>pI*z.
//System.out.print(" now:"+now+"\n"); K<'L7>s3lA
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |-GmW SK_
lastExecuteTime=now; mZDL=p
executeUpdate(); ;$gZ?&
} ?9hw]Q6r}
else{ u;rK.3o
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); uKHkC.g
} GP6-5Y"8
} E~Eh'>Y(B
} + Bk"
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//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 |d\rCq >
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类写好了,下面是在JSP中如下调用。 VDq4n;p1
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<% d5mhk[p7\J
CountBean cb=new CountBean(); *F|j%]k~
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *NzHY;e
CountCache.add(cb); Z".mEF-b
out.print(CountCache.list.size()+"<br>"); !mLQdkTE
CountControl c=new CountControl(); o7Ms]AblT
c.run(); V~ph1Boz2
out.print(CountCache.list.size()+"<br>"); }GX[N\$N
%>