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: t@4vEKw?.X
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CountBean.java 3@}_ F<"*
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/* cb
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* CountData.java +bQn2PG=
* =h&^X>!
* Created on 2007年1月1日, 下午4:44 rP3)TeG6
*
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* To change this template, choose Tools | Options and locate the template under S"_vD<q
* the Source Creation and Management node. Right-click the template and choose r+Z+x{
* Open. You can then make changes to the template in the Source Editor. 95(VY)_6#A
*/ S)[2\Z{**T
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package com.tot.count; S[ 2`7'XV
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/** (m,O!935f
* Z1OcGRN!
* @author gr-%9=Uq
*/ |]B]0J#_
public class CountBean { $~9U-B\
private String countType; (
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int countId; oYqC"g&4Z
/** Creates a new instance of CountData */ "\V:W%23W{
public CountBean() {} `[ne<F?e
public void setCountType(String countTypes){ [S9n F
this.countType=countTypes; "<.b=mN-
} c76^x
public void setCountId(int countIds){ 4H " *.l
this.countId=countIds; Nd6N:1-
} ;N,7#l|wi
public String getCountType(){ "n05y}
return countType; km3-Hp1
} xbmOch}j6
public int getCountId(){ VSSiuo'5w
return countId; ;j52a8uE'}
} p4el9O&-tV
} 2<J82(4j
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CountCache.java ?dTz?C.w
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/* "5YsBih
* CountCache.java )<~b*^kl\
* +)F8YMg
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* Created on 2007年1月1日, 下午5:01 Lv5AtZl}
* ^^%*2^
* To change this template, choose Tools | Options and locate the template under 7"S|GEs:
* the Source Creation and Management node. Right-click the template and choose kPxrI=
* Open. You can then make changes to the template in the Source Editor. {fS/ZG"5<t
*/ QVFa<>8/md
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package com.tot.count; {<|0M%v
import java.util.*; ?pVODnP k
/** >
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* MZ+"Arzb
* @author T$q]iSgu
*/ $4eogI7N>w
public class CountCache { f< '~K
public static LinkedList list=new LinkedList(); :{Y,Nsa
/** Creates a new instance of CountCache */ KT|$vw2b
public CountCache() {} cq!>B{
public static void add(CountBean cb){ D #A9
if(cb!=null){ T8RQM1D_s
list.add(cb); 8m6L\Z&
} }SOj3.9{c
} XCt}>/"s\h
} %b_zUFHPp
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CountControl.java LAvAjvRc
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/* ciXAyT cG
* CountThread.java HAU8H'h
* 9:esj{X
* Created on 2007年1月1日, 下午4:57 HWHGxg['r
* .jRXHrK;
* To change this template, choose Tools | Options and locate the template under k r/[|.bq
* the Source Creation and Management node. Right-click the template and choose CE+\|5u
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* Open. You can then make changes to the template in the Source Editor. vu*08<M~i|
*/ WM"I
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package com.tot.count; Aimgfxag
import tot.db.DBUtils; ukPV nk
import java.sql.*; zz$*upxK
/**
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* \dCdyl6V
* @author $QY(7Z"
*/ g,q&A$Wi
public class CountControl{ a(<nk5
private static long lastExecuteTime=0;//上次更新时间 z?K+LTf8
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 RLIugz{IH
/** Creates a new instance of CountThread */ d:j$!@o
public CountControl() {} O!|:ZMjF
public synchronized void executeUpdate(){ sNNt0q(
Connection conn=null; AAs&wYp8Yh
PreparedStatement ps=null; ;1o"Oij
try{ #2`tsZ]=I
conn = DBUtils.getConnection(); &-&6ARb7o
conn.setAutoCommit(false); 0phGn+"R
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); h?idRaN_
for(int i=0;i<CountCache.list.size();i++){ b0
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CountBean cb=(CountBean)CountCache.list.getFirst(); {0[qERj"z
CountCache.list.removeFirst(); *W0`+#Dcv
ps.setInt(1, cb.getCountId()); DsP+#PX
ps.executeUpdate();⑴ @F=4B0=
//ps.addBatch();⑵ \K>6-0r|
} }$OQw'L[
//int [] counts = ps.executeBatch();⑶ _@HMk"A
conn.commit(); _E?(cWC
}catch(Exception e){ "V^(i%E;
e.printStackTrace(); 'g$|:bw/
} finally{ .m4K ]^m
try{ \BS^="AcpP
if(ps!=null) { 0lW}l9}'-
ps.clearParameters(); udw5A*Ls
ps.close(); j:fL_1m
ps=null; F02NnF
} sbG3,'i)
}catch(SQLException e){} ~s
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DBUtils.closeConnection(conn); \=nY&Ml
} ]xFd_OHdb
} ./[t'dgC
public long getLast(){ 4|*_mC
return lastExecuteTime; A}W&=m8!
} xKIm2% U9
public void run(){ 7gvkd+-*
long now = System.currentTimeMillis(); (h2bxfV~+
if ((now - lastExecuteTime) > executeSep) { UW40Y3W0
//System.out.print("lastExecuteTime:"+lastExecuteTime); "&>$/b$
//System.out.print(" now:"+now+"\n"); fv}h;?C
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); fD
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lastExecuteTime=now; 7kj#3(e
executeUpdate(); sl`\g1<{`
} )<!y_;$A
else{ qQ^]z8g6P
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); <b{ApsRJf
} }yXa1#3
} k(V#{
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} "tm2YUG},s
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 z}kD:A)a
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类写好了,下面是在JSP中如下调用。 (L
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<% @y)fR.!)1$
CountBean cb=new CountBean(); F2lTDuk>C
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); r"k\G\,%
CountCache.add(cb); v vOG]2z
out.print(CountCache.list.size()+"<br>"); Ey 4GyAl
CountControl c=new CountControl(); D4[t@*m>7
c.run(); Un7jzAvQ
out.print(CountCache.list.size()+"<br>"); MdCEp1Z
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