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: zYzV!s2^
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CountBean.java R U)(|;
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/* "B QnP9
* CountData.java Z- feMM
* C8m 9H8Qm
* Created on 2007年1月1日, 下午4:44 b,'O|s]"Sc
* I}PI
* To change this template, choose Tools | Options and locate the template under 6H |1IrG
* the Source Creation and Management node. Right-click the template and choose >jt2vU@t.
* Open. You can then make changes to the template in the Source Editor. SwOW%o
*/ k8D_
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package com.tot.count; </ [.1&S+\
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/** /3,/j)`a
* ovKM;cRs/
* @author 2+9VDf2
*/ jR%*,IeB
public class CountBean { gG?@_ie
private String countType; -#ZvjEaey
int countId; PYCN3s#Gi
/** Creates a new instance of CountData */ "# *W#ohVA
public CountBean() {} #8Bh5L!SJ1
public void setCountType(String countTypes){ g~DuK|+
this.countType=countTypes; !1l~UB_
} n3iiW\
public void setCountId(int countIds){ `*s:[k5k
this.countId=countIds;
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} ea=E/HR-
public String getCountType(){ Z|t=t"6"
return countType; s+:|b~
} n\+c3
public int getCountId(){ }a;xs};X;
return countId; R1zt6oY
} $7q3[skH
} 4aHogheg
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CountCache.java oxxuw
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/* ~e}JqJ(97
* CountCache.java YY;<y%:8Z
* N`W[Q>n
* Created on 2007年1月1日, 下午5:01 kyHli~Nr"
* Rzd`MIHDp
* To change this template, choose Tools | Options and locate the template under mi=mwN%UB
* the Source Creation and Management node. Right-click the template and choose M`Q$-#E:
* Open. You can then make changes to the template in the Source Editor. 9tHK_),9
*/ ^`cv6;)
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package com.tot.count; >eTbg"\
import java.util.*; P<vl+&*
/** >+{WiZ`
* Ksx-Y"
* @author S>oEk3zlw
*/ QoYEWXT|g
public class CountCache { pA!-spgX
public static LinkedList list=new LinkedList(); cKVFykwM
/** Creates a new instance of CountCache */ ^*AI19w!Ys
public CountCache() {} ]Q"T8drL
public static void add(CountBean cb){ TsFhrtnx&X
if(cb!=null){ S70#_{
list.add(cb); [QnN1k
} "W(D0oy
} }PI:O%N;
} I0mp [6
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CountControl.java `0Udg,KOs
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/* *'?ZG/ (
* CountThread.java Kg6J:HD49
* s, Gl{
* Created on 2007年1月1日, 下午4:57 ek&~A0k_o
* |.@!CqJ
* To change this template, choose Tools | Options and locate the template under T1C_L?L
* the Source Creation and Management node. Right-click the template and choose :Q`Of}#
* Open. You can then make changes to the template in the Source Editor. Q+Bl1xl
*/ 'APx
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package com.tot.count; H@(O{ 9Yl;
import tot.db.DBUtils; 7Yg1z%%U
import java.sql.*; `Abd=1nH
/** LGhK)]:
* j-9)Sijj{
* @author cM%?Ot,mK"
*/ pN^g.
public class CountControl{ #aX#gh}1
private static long lastExecuteTime=0;//上次更新时间 Z1,rN#p9
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 nL?P/ \
/** Creates a new instance of CountThread */ Gi)Vr\Q.
public CountControl() {} "lt <$.
public synchronized void executeUpdate(){ |"}rdOV)
Connection conn=null; }R;}d(C`
PreparedStatement ps=null; 1WtE ]
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try{ AGFA;X
conn = DBUtils.getConnection(); 54p{J
conn.setAutoCommit(false); Z' i@;^=A
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); :u7BCV|yr
for(int i=0;i<CountCache.list.size();i++){ =K:[26
CountBean cb=(CountBean)CountCache.list.getFirst(); s",Ea*
CountCache.list.removeFirst(); :aOR@])>o
ps.setInt(1, cb.getCountId()); ^=x /:0
ps.executeUpdate();⑴ |Z>-<]p9g
//ps.addBatch();⑵ i"V.$|,
} )5@P|{FF
//int [] counts = ps.executeBatch();⑶ 2WS*c7Ct
conn.commit(); &h/r]KrZ
}catch(Exception e){ {z>!Fw
e.printStackTrace(); `dm*vd
} finally{ &>AwG4HW#j
try{ My>q%lF=fw
if(ps!=null) { +JI,6)Ry
ps.clearParameters(); 'u.Dt*.Uq
ps.close(); B :%Vq2`
ps=null; 43k'96[2d
} l0'Yq%Nf
}catch(SQLException e){} Nk@-yZ@,8
DBUtils.closeConnection(conn); Mst%]@TG
} [0Xuo
} GFT@Pqq
public long getLast(){ _S) K+C|@
return lastExecuteTime; frcX'M}%
} /%cDX:7X
public void run(){ *Hx*s_F
long now = System.currentTimeMillis(); a]Pi2:S
if ((now - lastExecuteTime) > executeSep) { %fg6',2
//System.out.print("lastExecuteTime:"+lastExecuteTime); H@-q NjM
//System.out.print(" now:"+now+"\n"); +=/j+S`
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); LZ)g&A(j?
lastExecuteTime=now; d*tWFr|J-
executeUpdate(); t0f7dU3e;L
} h2'6W)
else{ bf/6AY7
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); J299mgB
} Y%/RGYKh
} 4
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} ] !*K|?VL
//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 J%"5?)[z
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类写好了,下面是在JSP中如下调用。 to:
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#[bosb!R
<% )bg |l?
CountBean cb=new CountBean(); M
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); t<te{yt%
CountCache.add(cb); 3!9JXq%Hl
out.print(CountCache.list.size()+"<br>"); M_!]9#:K7
CountControl c=new CountControl(); d21thV ,S
c.run(); 2D%2k
out.print(CountCache.list.size()+"<br>"); {*;8`+R&
%>