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: { k>T*/
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CountBean.java *47HN7
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/* Q@ua
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* CountData.java >npTUOGL=n
* (1e,9!?
* Created on 2007年1月1日, 下午4:44 O!se-h5mW8
* MFeY}_d<
* To change this template, choose Tools | Options and locate the template under fU<_bg
* the Source Creation and Management node. Right-click the template and choose >=1A a,_tc
* Open. You can then make changes to the template in the Source Editor. U3u j`Oq
*/ U0=: `G2l
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package com.tot.count; xL [3R
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/** @d|3c7` A
* 2Q%*`
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* @author 8 qlQC.VA[
*/ I= 2jQ>$Q
public class CountBean { E(F?o.b
private String countType; jP#I](\eG
int countId; `*WzHDv5p
/** Creates a new instance of CountData */ IY
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public CountBean() {} hx! :F"#
public void setCountType(String countTypes){ NY?pvb
this.countType=countTypes; 'i<%kL@
} &'k:?@J[
public void setCountId(int countIds){ $MqEM~^=
this.countId=countIds; !K6:5V%q$
} ";jKTk7
public String getCountType(){ n"w>Y)C(X)
return countType; ' ""s%C+
} :{,k F
public int getCountId(){ cs9"0&JX
return countId; ioBYxbY`
} ^+w1:C 5
} 3tW}a`z9
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CountCache.java f}EsS
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/* %$_Y"82
* CountCache.java 5,|of{8
* [Lcy &+
* Created on 2007年1月1日, 下午5:01 dDA,Ps
* ):\+%v^
* To change this template, choose Tools | Options and locate the template under wbB\~*Z)
* the Source Creation and Management node. Right-click the template and choose G\R6=K:f7
* Open. You can then make changes to the template in the Source Editor. H#M;TjR
*/ %%9T-+T
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package com.tot.count; Pv|sPIIB7
import java.util.*; P6")OWd
/** ]c1#_MW
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* @author x\IuM
*/ IOa@dUh7a,
public class CountCache { <sn,X0W
public static LinkedList list=new LinkedList(); XP[~ :+
/** Creates a new instance of CountCache */ Tv `&
public CountCache() {} |9Y~k,rF
public static void add(CountBean cb){ ]F"P3':
if(cb!=null){ vXZ
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list.add(cb); (Vn3g ra
} nt@uVwfQ
} :;;k+Sw3
} 0EasPbp
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CountControl.java ']d(m?
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/* h7 mk<
* CountThread.java ;I6C`N
* m{&lU@uL
* Created on 2007年1月1日, 下午4:57 vs>Pd |p;
* cYvt!M\ed
* To change this template, choose Tools | Options and locate the template under 11Uu5e!.
* the Source Creation and Management node. Right-click the template and choose pU<GI@gU
* Open. You can then make changes to the template in the Source Editor. T)tTzgLD}
*/ t~$8sG\
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package com.tot.count; @V&HE:P
import tot.db.DBUtils; _Ea1;dJmq
import java.sql.*; IpM"k)HR
/** )NTpb
* XjmAM/H4
* @author Nrq/Pkmy
*/ A"0Yn(awWu
public class CountControl{ VF +g+~
private static long lastExecuteTime=0;//上次更新时间 UG vUU<N|N
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ;&!QN#_
/** Creates a new instance of CountThread */ (,|eE)+
public CountControl() {} Bc`L]<
public synchronized void executeUpdate(){ a'?LC)^
Connection conn=null; UR(i_T&w
PreparedStatement ps=null; t0za%q!fK<
try{ <dAxB$16sT
conn = DBUtils.getConnection(); 7+Nl)d:CJ
conn.setAutoCommit(false); EWq
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); wKoar
for(int i=0;i<CountCache.list.size();i++){ 6B Hdc
CountBean cb=(CountBean)CountCache.list.getFirst(); 6W~JM^F
CountCache.list.removeFirst(); X5-[v(/]
ps.setInt(1, cb.getCountId()); 9?^0pR p
ps.executeUpdate();⑴ ]AZCf`7/?
//ps.addBatch();⑵ ~jzT;9:
} p@h<u!rL8
//int [] counts = ps.executeBatch();⑶ @LY[kt6o
conn.commit(); lv~ga2>z
}catch(Exception e){ tv2k&\1
e.printStackTrace(); ` +)Bl%*
} finally{ jk Aru_C
try{ 06`caG|]-M
if(ps!=null) { r9<#R=r)}J
ps.clearParameters(); !|
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ps.close(); j3S!uA?
ps=null; "D:?l`\o
} sn
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}catch(SQLException e){} 'j?H>'t{
DBUtils.closeConnection(conn); zm_8{Rta}
} R?dMM
} k^#*x2b
public long getLast(){ :G=ol2Q
return lastExecuteTime; m 0Uu2Z4
} 9H53H"5q
public void run(){ G @]n(\7Y
long now = System.currentTimeMillis(); oW>e.}d!
if ((now - lastExecuteTime) > executeSep) { "*TP@X?@f
//System.out.print("lastExecuteTime:"+lastExecuteTime); 7#*`7 K'P!
//System.out.print(" now:"+now+"\n"); H`yUSB
IP
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); _bv9/# tR
lastExecuteTime=now; KI].T+I
executeUpdate(); 5 o[E8c8
} tVNFulcz$
else{ jN(c`Gb
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 'b6qEU#
} HIvSh6|0p
} hVCxwTg^X
} bn=7$Ax
//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 i-4?]h k
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类写好了,下面是在JSP中如下调用。 cnDF`7xrT
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<% \_)mWK,h
CountBean cb=new CountBean(); \ >#y*W<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ^e80S^
CountCache.add(cb); 7c<_j55(
out.print(CountCache.list.size()+"<br>"); "y ;0}9]n1
CountControl c=new CountControl(); jS|jPk|I.
c.run(); ,o0[^-b<
out.print(CountCache.list.size()+"<br>"); s-F3(mc(
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