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: nd`1m[7MNu
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CountBean.java DVO.FTV^`
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/* b3P+H r
* CountData.java Yz9owe8}[
* !@5 9)
* Created on 2007年1月1日, 下午4:44 [XN={
* NYhB'C2
* To change this template, choose Tools | Options and locate the template under RV1coC.g4x
* the Source Creation and Management node. Right-click the template and choose i}(LqcYU
* Open. You can then make changes to the template in the Source Editor. Do9x
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*/ M.JA.I@XC
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package com.tot.count; }czrj%6
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/** .zf~.R;>
* gZVc 5u<
* @author &L3M]
*/ ]|#+zx|/D
public class CountBean { "BAK !N$9
private String countType; g9OY<w5s]
int countId; BqEI(c6
/** Creates a new instance of CountData */ r[e##M
public CountBean() {} (xycJ`N
public void setCountType(String countTypes){ ?C]vS_jAh
this.countType=countTypes; 6dHOf,zjm
} z,RhYm
public void setCountId(int countIds){ Q(G#W+r
this.countId=countIds; pt?bWyKG
} NCveSP
public String getCountType(){ )',R[|<
return countType; -+-?w|}qV
} YH$-g
public int getCountId(){ 53_Hl]#qZ
return countId; pR<`H'
} SV4E0c>
} p;a,#IJu
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CountCache.java #{0HYg?(f
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/* &{5,:%PXw
* CountCache.java sVQ|*0(J0r
* bt SRtf
* Created on 2007年1月1日, 下午5:01 cs48*+m
* 39c2pV[
* To change this template, choose Tools | Options and locate the template under =<C:d
* the Source Creation and Management node. Right-click the template and choose >\R+9p:o
* Open. You can then make changes to the template in the Source Editor. /|w6:;$;mn
*/ `6;?9NI
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package com.tot.count; + SzU
import java.util.*; 3qgS&js 7
/** uuEV_ "X
* 6dQ-HI*Y#
* @author a9e>iU
*/ 2B1q*`6R
public class CountCache { P.se'z)E
public static LinkedList list=new LinkedList(); rE7G{WII
/** Creates a new instance of CountCache */ PxX4[ P
public CountCache() {} LG0;#3YwH
public static void add(CountBean cb){ h#I>M`|
if(cb!=null){ $V;i
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list.add(cb); 4IK( 7
} lM`2sy
} 2g
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} ]2A^1Del
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CountControl.java >fG3K`
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/* _`$qBw.Nx
* CountThread.java U)TUOwF
* 299H$$WS,Z
* Created on 2007年1月1日, 下午4:57 !vi>U|rh
* D_ 2:k'4
* To change this template, choose Tools | Options and locate the template under j8i[ONq^
* the Source Creation and Management node. Right-click the template and choose >IafUy
* Open. You can then make changes to the template in the Source Editor. te`$%NRl
*/ E)&I@m
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package com.tot.count; Yu/ID!`Z
import tot.db.DBUtils; krxo"WgD
import java.sql.*; OG~gFZr)6
/** u2I*-K
* r+!YIk
* @author \<h0Q,e
*/ -/B+T>[nTb
public class CountControl{ Z3e| UAif
private static long lastExecuteTime=0;//上次更新时间 uh_RGM&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 *tFHM &a
/** Creates a new instance of CountThread */ "s-"<&>a(
public CountControl() {} a~`eQ_ND
public synchronized void executeUpdate(){ k8yEdi`
Connection conn=null; Eh`7X=Z7E
PreparedStatement ps=null; Ufj`euY
try{ ,^r9n[M4M
conn = DBUtils.getConnection(); )iX~}7
conn.setAutoCommit(false); o#)C^xlQ
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 'c&Ed
for(int i=0;i<CountCache.list.size();i++){ T.F!+
CountBean cb=(CountBean)CountCache.list.getFirst(); hW')Sp
CountCache.list.removeFirst(); P;y45b
ps.setInt(1, cb.getCountId()); RU{twL.B
ps.executeUpdate();⑴ ? V1*cVD6i
//ps.addBatch();⑵ yu {d! {6
} t,Lrfv])
//int [] counts = ps.executeBatch();⑶ >{]%F*p4
conn.commit(); G5_=H,Vmd
}catch(Exception e){ umfD>" ^I
e.printStackTrace(); ~D+bh~
} finally{ 1nM
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try{ ldcqe$7,
if(ps!=null) { 68|E9^`l
ps.clearParameters(); S\EyCi+
ps.close(); f%JIp#B
ps=null; ITQA0PISL
} w(Ovr`o?9t
}catch(SQLException e){} )}R0Y=e
DBUtils.closeConnection(conn); ~NgA
} Ib!R D/
} + J{IRyBc
public long getLast(){ unzr0x
{
return lastExecuteTime; `7Q<'oK
} gaxsv[W>^
public void run(){ +^ac'Y)A
long now = System.currentTimeMillis(); P:S .~Jq
if ((now - lastExecuteTime) > executeSep) { \w>y`\6mX
//System.out.print("lastExecuteTime:"+lastExecuteTime); hFUlNJ
//System.out.print(" now:"+now+"\n"); 5~U/
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 2W(s(-hD
lastExecuteTime=now; I|!OY`ko
executeUpdate(); hag$GX'2k
} c]-<vkpV
else{ Gu,wF(x7A
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); o[4}h:> dq
} l4YbK np]
} c]<5zyl"j1
} 0o4XUW
//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 k'Hs}z eNn
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类写好了,下面是在JSP中如下调用。 p>N(Typ0b
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<% `hm-.@f,9
CountBean cb=new CountBean(); ?<,l3pwqa
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); A2FYBM`Q&D
CountCache.add(cb); qwcD`HV,
out.print(CountCache.list.size()+"<br>"); \K{
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CountControl c=new CountControl(); ]c*4J\s
c.run(); qZh/IW
out.print(CountCache.list.size()+"<br>"); =*.~BG
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