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: Uskz~~}G
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CountBean.java <Wqk5mR
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/* Ky(=O1Ufu
* CountData.java ixJ%wnz
* C
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* Created on 2007年1月1日, 下午4:44 MhT.Zg\
* ti%uyXfja
* To change this template, choose Tools | Options and locate the template under #ub!
* the Source Creation and Management node. Right-click the template and choose 2g?O+'JD
* Open. You can then make changes to the template in the Source Editor. 8y:c3jzP_
*/ 33/aYy
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package com.tot.count; =GGt:3Kx-
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/** u^5X@.
* 57PoJ+
* @author [R-&5 G!x
*/ ~m@v ~=
public class CountBean { dB`3"aSN7
private String countType; Pi7IBz
int countId; bvpP/LeY
/** Creates a new instance of CountData */ (x"TM),Q
public CountBean() {} 0 1~&H8 =
public void setCountType(String countTypes){ &T"X
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this.countType=countTypes; x|3f$
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} y<#?z 8P
public void setCountId(int countIds){ #RIo63
this.countId=countIds; n\CQ-*;l
} h0;PtQb1
public String getCountType(){ 0uZ 'j
return countType; CB&$tDi
} '(N -jk
public int getCountId(){ ^
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return countId; P01o: /}
} {-FS+D`
} kWkAfzf4a
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CountCache.java ~x}/>-d
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/* &tKr
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* CountCache.java ~D[5AXV`^
* ? dD<KCbP,
* Created on 2007年1月1日, 下午5:01 UM?{ba9
* CY{`IZ
* To change this template, choose Tools | Options and locate the template under (+_i^SqK
* the Source Creation and Management node. Right-click the template and choose !4gyrNS
* Open. You can then make changes to the template in the Source Editor. UBN^dbP*
*/ /<J&ZoeJB
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package com.tot.count; S4qj}`$
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import java.util.*; F%<hng%k
/** zzq7?]D
* \(m_3 H
* @author aDXdr\C6
*/ H?ZlJ|/c
public class CountCache { ` #!~+
public static LinkedList list=new LinkedList(); EKwA1,Xz
/** Creates a new instance of CountCache */ x^s2bb
public CountCache() {} X}!r4<;(
public static void add(CountBean cb){ !sbKJ+V7
if(cb!=null){ 4d\"gk
list.add(cb); HkgmZw,
} X^pxu6nm-
} bu&x&
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} oSDx9%
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CountControl.java Lbo8>L(
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/* 1O<Gg<<,e
* CountThread.java f{]eb1
* g\Gx
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* Created on 2007年1月1日, 下午4:57 hX?rIx
* (
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* To change this template, choose Tools | Options and locate the template under {u/G!{N$
* the Source Creation and Management node. Right-click the template and choose Z @:5vo
* Open. You can then make changes to the template in the Source Editor. v7;zce/~
*/ ,}9 G|$
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package com.tot.count; ?52{s"N0>
import tot.db.DBUtils; 'eKvt5&@
import java.sql.*; N{lj"C]L
/** /hC[>t<
* st8=1}:&\
* @author [P'crV,m
*/ cyR K&J
public class CountControl{ 32DSZ0
private static long lastExecuteTime=0;//上次更新时间 F4=+xd >0
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ~S5wfx&
/** Creates a new instance of CountThread */ MT`gCvoF4P
public CountControl() {} Cd>GY
public synchronized void executeUpdate(){ x2 s%qZ#
Connection conn=null; s|/m}n
PreparedStatement ps=null; sk0N=5SB-
try{ a{?`yO/ 2
conn = DBUtils.getConnection(); mY}_9rTn|
conn.setAutoCommit(false); =U:9A=uEvS
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); vrS)VJg`
for(int i=0;i<CountCache.list.size();i++){ lu]Z2xSv
CountBean cb=(CountBean)CountCache.list.getFirst(); }Pu|%\
CountCache.list.removeFirst(); 1pT
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ps.setInt(1, cb.getCountId()); yQ^k%hHa
ps.executeUpdate();⑴ 6mFH>T*jzH
//ps.addBatch();⑵ D)yCuw{M:
} XDtr{r6z
//int [] counts = ps.executeBatch();⑶ d+
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conn.commit(); :'\4%D=w
}catch(Exception e){ [31vx0$_p
e.printStackTrace(); ^qs{Cf$
} finally{ )X8?m <cG
try{ 3ug|H
if(ps!=null) { 4v@urW s
ps.clearParameters(); fxW,S
ps.close(); 6]GEn=t
ps=null; ^H0`UKE
} fB\+.eN
}catch(SQLException e){} ^uU'Qc4S=
DBUtils.closeConnection(conn); 9t`Z_HwdCb
} A5d(L4Q]a(
} [dszz7/L
public long getLast(){ sd (I@
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return lastExecuteTime; ;n-)4b]\
} # g.J,L
public void run(){ P)7_RE*gY
long now = System.currentTimeMillis(); /F>\-
if ((now - lastExecuteTime) > executeSep) { <"SDU_<xG
//System.out.print("lastExecuteTime:"+lastExecuteTime); Je|D]w
//System.out.print(" now:"+now+"\n"); IEi E6z]L(
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Z */*P4\
lastExecuteTime=now; f87>ul!*
executeUpdate(); Hk65c0
} c*O{?b
else{ c1v,5c6d j
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Ch`nDIne
} 0YMmW xV
} s_(%1/{
} aFI?^"L
//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 ,bv?c@
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类写好了,下面是在JSP中如下调用。 ##%R|P3
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<% Q?Au.q],
CountBean cb=new CountBean(); wm3fd7T
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); AR<'Airi:
CountCache.add(cb); "IOu$?
out.print(CountCache.list.size()+"<br>"); j( *;W}*^
CountControl c=new CountControl(); 'IaI7on
c.run(); /}~;
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out.print(CountCache.list.size()+"<br>"); 9fWr{fx
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