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: $T6<9cB@
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CountBean.java >wn&+%i&
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/* @1pdyKK
* CountData.java =F`h2 A;a
* gm8H)y,
* Created on 2007年1月1日, 下午4:44 _R]1J0
* FR&RIFy
* To change this template, choose Tools | Options and locate the template under REw3>/=
* the Source Creation and Management node. Right-click the template and choose HZm44y$/
* Open. You can then make changes to the template in the Source Editor. [x&&N*>N
*/ * PZ=$>r
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package com.tot.count; `yhL11]~
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/** }E=mZZ)
* m=R4A4Y7
* @author U>>J_2
*/ 1osI~oNZ
public class CountBean { @ZmpcoDI
private String countType; f?]cW h%
int countId; )z aMycW
/** Creates a new instance of CountData */ UY==1\
public CountBean() {} @U&|38
public void setCountType(String countTypes){ ZE :oK
this.countType=countTypes; Deam%)bXM]
} rScmUt
public void setCountId(int countIds){ au8)G_A
this.countId=countIds; 2XE4w# [j
} ELm#
public String getCountType(){ hZpFI?lqc\
return countType; }>j$Wr_h
} Bg3^BOT
public int getCountId(){ 33; ytd
return countId; Nb$ )YMbA
} 5=dg4"b]
} !vsUL-
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CountCache.java d#(xP2
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/* p%?R;W`u2
* CountCache.java Q|0[B4e^:
* m\t
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* Created on 2007年1月1日, 下午5:01 YrdK@I
* `pKQ|zGw
* To change this template, choose Tools | Options and locate the template under 1*a2s2G
'
* the Source Creation and Management node. Right-click the template and choose w<'mV^S
* Open. You can then make changes to the template in the Source Editor. <"t >!I
*/ {30A1>0#P
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package com.tot.count; $FAl9
import java.util.*; ]!f=b\-Av
/** _ K9jj
* Gf"/fpeQx
* @author ''V:+@Toh
*/ rsP1?Hxq
public class CountCache { zRz3ot,|
public static LinkedList list=new LinkedList(); ci$o~b6V
/** Creates a new instance of CountCache */ FNUue
public CountCache() {} |ey6Czm
public static void add(CountBean cb){ T# 8O:
if(cb!=null){ &BQ`4j~.
list.add(cb); +>s[w{Svy
} F`3I~(
} p1Els/|
} WUHijHo5(8
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CountControl.java :+u?A
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/* [1s B
* CountThread.java rc"Z$qU?
* `InS8PLr
* Created on 2007年1月1日, 下午4:57 U?kJXM2
* $FD0MrB_+
* To change this template, choose Tools | Options and locate the template under N[AX29
* the Source Creation and Management node. Right-click the template and choose J3K!@m_\
* Open. You can then make changes to the template in the Source Editor. 2cww7z/B
*/ TEY%OIzU+
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package com.tot.count; 2r1.,1
import tot.db.DBUtils; rHP5;j<]
import java.sql.*; chxO*G
/** ,l~i|_
* (pAGS{{
* @author lwa
*/ Peb;XI
public class CountControl{ IAg#YFI
private static long lastExecuteTime=0;//上次更新时间 GUMO;rZs
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ?-6oh~W<
/** Creates a new instance of CountThread */ mio\}SA
public CountControl() {} 8)T.[AP
public synchronized void executeUpdate(){ ;Lz96R@}
Connection conn=null; O[$&]>x]]
PreparedStatement ps=null; 8E|S`I
try{ (A?/D!y
conn = DBUtils.getConnection(); wVp
conn.setAutoCommit(false); v\&Wb_;A
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); :dB6/@fW
for(int i=0;i<CountCache.list.size();i++){ ZXp=QH+f
CountBean cb=(CountBean)CountCache.list.getFirst(); 40mgB4I
CountCache.list.removeFirst(); zU]95I
ps.setInt(1, cb.getCountId()); $+-2/=>Xk
ps.executeUpdate();⑴ >8EIm
//ps.addBatch();⑵ yw2sK7
} \= i>}Sg
//int [] counts = ps.executeBatch();⑶ @*!8
conn.commit(); =`u4xa#m
}catch(Exception e){ 10t9Qv/
e.printStackTrace(); S)p1[&" M
} finally{ 3s"x{mtH
try{ A=Dzd/CUO
if(ps!=null) { HPT$)NeNc
ps.clearParameters(); GXf"a3
ps.close(); Eufw1vDa
ps=null; KxqJlben
} R{u/r%
}catch(SQLException e){} }fdo
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DBUtils.closeConnection(conn); L-vy,[9)[*
} )nQA) uz
} j#zUO&Q@
public long getLast(){ P6@(nGgK<
return lastExecuteTime; !Yd7&#s
} !bRoNP
public void run(){ ?X~Keb
long now = System.currentTimeMillis(); 94\k++kc
if ((now - lastExecuteTime) > executeSep) { ?o?~Df&
//System.out.print("lastExecuteTime:"+lastExecuteTime); "1yXOy^2
//System.out.print(" now:"+now+"\n"); Fn1|Wt*
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); J1KV?aR
lastExecuteTime=now; \= =rdW-
executeUpdate(); 8 Zhx&
} >Ta|#]{
else{ {L4ta~2/T
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); $0=f9+@5
} }y;s(4
} 4:WN-[xX
} 3%p^>D\
//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
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类写好了,下面是在JSP中如下调用。 t&*X~(Yb!
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<% :/A3l=}iV
CountBean cb=new CountBean(); EA) K"C
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); B=8],_
CountCache.add(cb); +O8rjVg)
out.print(CountCache.list.size()+"<br>"); `2.[8%6
CountControl c=new CountControl(); krnxM7y
c.run(); _vr>-:G
out.print(CountCache.list.size()+"<br>"); ;Hk{bz(
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