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: >\JPX
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CountBean.java #c|l|Xvq2
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/* RY5e%/bg~U
* CountData.java xbiprhdv
* u8"s#%>Ny
* Created on 2007年1月1日, 下午4:44 ca=MUm=B
* <(E)M@2
* To change this template, choose Tools | Options and locate the template under q;SD+%tI
* the Source Creation and Management node. Right-click the template and choose t_/qd9Jv
* Open. You can then make changes to the template in the Source Editor. o9sQ!gptw
*/ wo9R:kQ
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package com.tot.count; L'y0$
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/** C5=^cH8
* )F9IzR-&m
* @author Qe~C}j%
*/ #|\|G3Si
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public class CountBean { I85wP}c(
private String countType; 0+0Y$;<
int countId; wW TuEM
/** Creates a new instance of CountData */ ;)rhx`"n
public CountBean() {} z{R
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public void setCountType(String countTypes){ ejg!1*H@n
this.countType=countTypes; J#d,?
} 0,0WdJAe
public void setCountId(int countIds){ y1`%3\
this.countId=countIds; T3b0"o27
} }5E H67
public String getCountType(){ 0yjYjIk"T
return countType; []OS p&
} wgSFL6Ei
public int getCountId(){ `@Z$+
return countId; }r04*P(
} R1*&rjB
} n_sV>$f-u
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CountCache.java 2Jo|P A`9
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/* n(A;:)W{
* CountCache.java +46& Zb35
* _WV13pnRu
* Created on 2007年1月1日, 下午5:01 b?k,_;\
* m<Gd 6V5
* To change this template, choose Tools | Options and locate the template under s#~VN;-I
* the Source Creation and Management node. Right-click the template and choose :Nz
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* Open. You can then make changes to the template in the Source Editor. %m|BXyf]_B
*/ @>`N%wH'
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package com.tot.count; OfLj 4H6Q
import java.util.*; H(
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/** )m-(- I
* ,9OER!$y
* @author NX8w(~r,:
*/ :CM2kh"Iu
public class CountCache { <MxA;A
public static LinkedList list=new LinkedList(); .:-*89c
/** Creates a new instance of CountCache */ k H06Cb
public CountCache() {} Xk^<}Ep)c
public static void add(CountBean cb){ y] Q/(O
if(cb!=null){ fN`Prs A
list.add(cb); $7-4pW$y
} 1\jj3Y'i'
} ^b&hy&ag
} g6q[
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CountControl.java ziAn9/sT
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/* Dmtsu2o
* CountThread.java &WbHM)_n
* qE^u{S4Z@
* Created on 2007年1月1日, 下午4:57 .>5E 4^$%
* kDKfJp&a
* To change this template, choose Tools | Options and locate the template under \a:-xwUu<
* the Source Creation and Management node. Right-click the template and choose c*8k _o,
* Open. You can then make changes to the template in the Source Editor. <l)I%1T_c
*/ >+BLD
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package com.tot.count; R*"zLJP
import tot.db.DBUtils; pr"q-S>E
import java.sql.*; 7*&q"
/** *=QWx[K|
* }8'bXG+
* @author #w[Ie+
*/ uY)|
public class CountControl{ kEdAt5/U{
private static long lastExecuteTime=0;//上次更新时间 LZpqv~av
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 l;J B;0<s"
/** Creates a new instance of CountThread */ !uHVg(}
public CountControl() {} ID=^497
public synchronized void executeUpdate(){ !_1RQ5]^
Connection conn=null; "IdN *K
PreparedStatement ps=null; gM#]o QOGE
try{ wtro'r3
conn = DBUtils.getConnection(); 4q^'MZm1
conn.setAutoCommit(false); DmpD`^?-L
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); #F >R5 D
for(int i=0;i<CountCache.list.size();i++){ mvW,nM1Y
CountBean cb=(CountBean)CountCache.list.getFirst(); ,
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CountCache.list.removeFirst(); NHzhGg]
ps.setInt(1, cb.getCountId()); IsiCHtY9
ps.executeUpdate();⑴ AtlUxFX0S
//ps.addBatch();⑵ Rp""&0
} U{.y X7
//int [] counts = ps.executeBatch();⑶ |NWo.j>4-
conn.commit(); }W* q
}catch(Exception e){ lZ }H?n%
e.printStackTrace(); *1b)Va8v*
} finally{ m:{IVvN_
try{ ^{fA:N=
if(ps!=null) { &Ukh
ps.clearParameters(); d#3E'8
ps.close(); 1A\N$9Dls
ps=null; Zut"P3d=J
}
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}catch(SQLException e){} q vGkTE
DBUtils.closeConnection(conn); B"I^hrQ
} V> @+&q
} HO
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public long getLast(){ Dj@7vM%_
return lastExecuteTime; .q(1
} {`1gDKH
public void run(){ EJ`"npU
long now = System.currentTimeMillis(); iyf vcKO
if ((now - lastExecuteTime) > executeSep) { &,~Oi(SX5
//System.out.print("lastExecuteTime:"+lastExecuteTime); -|A`+1-R+
//System.out.print(" now:"+now+"\n"); uz;z+Bd^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;sn]Blpq
lastExecuteTime=now; 1|Z!8:&pj
executeUpdate(); Mu]1e5^]
} iqPMCOPZ
else{ KI{B<S3*Z
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); avo[~ `.
} f&
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} /V@9!
} =Hwlo!
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 s xp>9&
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类写好了,下面是在JSP中如下调用。 Dm0Ts~
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<% ~*Kk+w9H<
CountBean cb=new CountBean(); -kz9KGkPb+
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Ga1(T$|H
CountCache.add(cb); 9(
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out.print(CountCache.list.size()+"<br>"); n6]8W^g
CountControl c=new CountControl(); rsgTd\b
c.run(); zLda+
out.print(CountCache.list.size()+"<br>"); VuWBWb?0Q
%>