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: _D[vMr[
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CountBean.java T'0Ot3m`
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/* ci6j"nKci
* CountData.java [gQ*y~N
* q/<.^X
* Created on 2007年1月1日, 下午4:44 hyVuZ\9B
* f4CwyL6ur
* To change this template, choose Tools | Options and locate the template under mf^(Tq[
* the Source Creation and Management node. Right-click the template and choose 2Pasmh
* Open. You can then make changes to the template in the Source Editor. ?RA^Y N*9
*/ Azq,N@HO
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package com.tot.count; )!e-5O49r
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/** dEJ>8e8
* %dKUB4
* @author %v4/.4sR,;
*/ )9l5gZX'I
public class CountBean { '$UlJDZ
private String countType; mdtq-v
int countId; =0MW+-
/** Creates a new instance of CountData */ /0\m;&
public CountBean() {} LezM=om.
public void setCountType(String countTypes){ BoHMz/DB
this.countType=countTypes; TCv}N0
} }q)oLC
public void setCountId(int countIds){ a<rk'4,8a
this.countId=countIds; sn]8h2z
} iKs/8n
public String getCountType(){ Nq"/:3@4
return countType; xW#r)aN]p
} W{?7Pn?1`
public int getCountId(){ *R0Ae 4
return countId; OtrO"K
} {xMY2I++
} 1wi{lJaz
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CountCache.java =;i@,{
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/* l{E+j%
* CountCache.java 5kofO
* #xNLr
* Created on 2007年1月1日, 下午5:01 ZS4lb=)G
* bWW$_Spr
* To change this template, choose Tools | Options and locate the template under qWfG@hn
* the Source Creation and Management node. Right-click the template and choose "P~0 7
* Open. You can then make changes to the template in the Source Editor. 6&`.C/"2
*/ #7/_Usso
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package com.tot.count; U(3{6^>Gc
import java.util.*; XA-DJ
/** ;SEH|_/
* (sq4
* @author CY<,p$
*/ o>';-} E
public class CountCache { ez"Xb 7
public static LinkedList list=new LinkedList(); Z1wN+Y.CA
/** Creates a new instance of CountCache */ oL2|@WNj,
public CountCache() {} o=X6PoJN_
public static void add(CountBean cb){ {]n5h#c 5*
if(cb!=null){ 1t
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list.add(cb); ^EPM~cEY\
} p%jl-CC1
} pkWzaf
} I;S[Ft8d
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CountControl.java A<C`JN}
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/* g PU|Gv5
* CountThread.java $o?Wum
* 1l"A7
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* Created on 2007年1月1日, 下午4:57 zC\ pd#
* pE[ul
* To change this template, choose Tools | Options and locate the template under Q?B5@J
* the Source Creation and Management node. Right-click the template and choose )F,H(LblH
* Open. You can then make changes to the template in the Source Editor. kQxY"HD
*/ <iajtq<Z
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package com.tot.count; Hc ]/0:
import tot.db.DBUtils; z)='MKrEt-
import java.sql.*; G,FYj'<!7,
/** #DXC6f
* BQ2EDy=}6
* @author <]r.wn=}M
*/ co r?#
public class CountControl{ x JQde 4
private static long lastExecuteTime=0;//上次更新时间 }eX zs_
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 7?:7}xb-
/** Creates a new instance of CountThread */ iov55jT~l@
public CountControl() {} 6kK\nZ$o$
public synchronized void executeUpdate(){ E5w.wx
Connection conn=null; 0(iTnzx0
PreparedStatement ps=null; ,Drd s"H
try{ )cNG)F
conn = DBUtils.getConnection(); "2o,XF
conn.setAutoCommit(false); "gADHt=MIR
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); }#Z Q\[
for(int i=0;i<CountCache.list.size();i++){ RY2`v
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CountBean cb=(CountBean)CountCache.list.getFirst(); *-(J$4RNz
CountCache.list.removeFirst(); \Lv
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ps.setInt(1, cb.getCountId()); lpQsmd#
ps.executeUpdate();⑴ ~+d?d6*c
//ps.addBatch();⑵ (1T2?mO
} qba<$
//int [] counts = ps.executeBatch();⑶ rR@ t5
conn.commit(); ,F`:4=H%
}catch(Exception e){ D642}VD
e.printStackTrace(); h@7Shp
} finally{ W'hE,
try{ zM%ILv4
if(ps!=null) { awQf$
ps.clearParameters(); .?UK`O2Q
ps.close(); <i``#"/
ps=null; 3P-qLbJ
} h7c8K)ntnf
}catch(SQLException e){} X3vTyIsn
DBUtils.closeConnection(conn); TBHIcX
} eN fo8xUG
} 7d*SZmD
public long getLast(){ Ml1yk)3G
return lastExecuteTime; -g(&5._,ZW
} uh*b[`e
public void run(){ 2T3v^%%j
long now = System.currentTimeMillis(); {|c
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if ((now - lastExecuteTime) > executeSep) { |v#N
//System.out.print("lastExecuteTime:"+lastExecuteTime); b&f;p}C24
//System.out.print(" now:"+now+"\n"); hPLQ)c?
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ^B8%Re%
lastExecuteTime=now; }\k"azQ`
executeUpdate(); -Qgu6Ty
} pRe, B'&
else{ UKMr,{iy
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); "z)dz,&T
} -(V]knIF
} +QT(~<
} 3YVG|Bc~_
//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 n0 q5|ES
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类写好了,下面是在JSP中如下调用。 Nlemb:'eP3
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<% mE^mQ [Dk
CountBean cb=new CountBean(); 6 "U&i9
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [h SE^
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CountCache.add(cb); Q]9H9?}N?
out.print(CountCache.list.size()+"<br>"); Ymkk"y.w
CountControl c=new CountControl(); 5<\&7P3y
c.run(); Y0fX\6=h
out.print(CountCache.list.size()+"<br>"); xZZW*d_b
%>