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: Hv,|XE@Y
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CountBean.java Sp`l>BL
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/* %6K7uvTq
* CountData.java 05UN
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* r]B8\5|<d
* Created on 2007年1月1日, 下午4:44 G gO5=|
* W4$o\yA]
* To change this template, choose Tools | Options and locate the template under V&Y`?Edc
* the Source Creation and Management node. Right-click the template and choose Ky3mzw|
* Open. You can then make changes to the template in the Source Editor. qGk+4 yC
*/ qF)J#$4;6
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package com.tot.count; a ~o<>H
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/**
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* b,!C8rJ
* @author g[xoS\d
*/ n ]%2Kx
public class CountBean { e=amh
private String countType; X><C#G
int countId; ew;;e|24
/** Creates a new instance of CountData */ mF~T?L"
public CountBean() {} %h.zkocM
public void setCountType(String countTypes){ U~G7~L &m
this.countType=countTypes; "8za'@D"f
} D%>Bj>xQD
public void setCountId(int countIds){ 5"%.8P
this.countId=countIds; q<RjAi
} )\wkVAm
public String getCountType(){ PgtLyzc
return countType; {X,%GI
} sG g458
public int getCountId(){ Bwg(f_[1
return countId; 79DNNj~
} ixTjXl2g
} n,T
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CountCache.java HZrA}|:h
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/* :UwBs
* CountCache.java d<c 29Y
*
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* Created on 2007年1月1日, 下午5:01 O]: 9va
* tFU4%c7V
* To change this template, choose Tools | Options and locate the template under k@xinK%O{
* the Source Creation and Management node. Right-click the template and choose A;cA|`b
* Open. You can then make changes to the template in the Source Editor. _|~Dj)z
*/ =<\22d5L
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package com.tot.count; }i9:k kfq2
import java.util.*; HwU9y
/** E|pT6
* S2X@t>u-
* @author "LlpZtw
*/ rfV'EjiM}
public class CountCache { =By@%ioIGG
public static LinkedList list=new LinkedList(); n"iS[uj,
/** Creates a new instance of CountCache */ *%uz LW0
public CountCache() {} U~
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public static void add(CountBean cb){ E}wT5t;u
if(cb!=null){ _\AQJ?<M
list.add(cb); *QK)
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} XtCIUC{r,
} lpT&v;$`
} &M-vKc"d
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CountControl.java 5OM#_.p
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/* eKLvBa-{@
* CountThread.java }6Pbjm *
* Bzz|2/1y
* Created on 2007年1月1日, 下午4:57 e'b*_Ps'
* lxd{T3LU
* To change this template, choose Tools | Options and locate the template under z ]f(lwo{
* the Source Creation and Management node. Right-click the template and choose #-|fdcb
* Open. You can then make changes to the template in the Source Editor. 1dvP2E
*/ o
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package com.tot.count; NuOA'e+i
import tot.db.DBUtils; 3a:Hx|
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import java.sql.*; _2KIe(,;
/** 'Agw~
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* @author ss-W[|cHU
*/ (]w6q&,
public class CountControl{ tE%g)hL-
private static long lastExecuteTime=0;//上次更新时间 <F^9ML+'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 \Zf=A[
/** Creates a new instance of CountThread */ ByqVNz0L
public CountControl() {} Zk`y"[ J
public synchronized void executeUpdate(){ =A!oLe$%
Connection conn=null; /? %V%
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PreparedStatement ps=null; 9L$OSy|
try{ tR51Pw
conn = DBUtils.getConnection(); GR|\OJ<2
conn.setAutoCommit(false); ~d7t\S
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 2l?^\9&
for(int i=0;i<CountCache.list.size();i++){ iM!Ya!
CountBean cb=(CountBean)CountCache.list.getFirst(); b}TvQ+W]2
CountCache.list.removeFirst(); h6k" D4o\
ps.setInt(1, cb.getCountId()); Z9:
ps.executeUpdate();⑴ -k + jMH
//ps.addBatch();⑵ ;gBR~W
} &G2&OFAr]q
//int [] counts = ps.executeBatch();⑶ 4eWv).
conn.commit(); gWgp:;Me
}catch(Exception e){ a&{Y~Og?%
e.printStackTrace(); fXWy9 #M
} finally{ %NQ
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try{ k'r} @-X
if(ps!=null) { (uX?XX^
ps.clearParameters(); H!*ypJ
ps.close(); FS}b9sQ)
ps=null; }etdXO_^
} !4Aj#`)
}catch(SQLException e){} g$]WKy(D
DBUtils.closeConnection(conn); t]I9[5Pq\
} kq X=3Zo
} *zUK3&n~I
public long getLast(){ p2Khfl6-
return lastExecuteTime; *AV%=
} Uha.8
public void run(){ xHt7/8wF
long now = System.currentTimeMillis(); ^EiU>
if ((now - lastExecuteTime) > executeSep) { Ma!
//System.out.print("lastExecuteTime:"+lastExecuteTime); .@): Uh
//System.out.print(" now:"+now+"\n"); Hc\C0V<
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); UYxn?W.g
lastExecuteTime=now; SY|K9$M^
executeUpdate(); eL~xS: VT
} 'IY?=#xr'`
else{ [.4{s
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); e1g3a1tnWl
} /4O))}TX
} fY^CIb$Y
} M(L6PyEa!Y
//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 3w)r"" C&
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类写好了,下面是在JSP中如下调用。 tAq0Z)
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<% .K84"Gdx
CountBean cb=new CountBean(); lrZ]c:%k
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 46]BRL2 G
CountCache.add(cb); YyYZD{^
out.print(CountCache.list.size()+"<br>"); /[dMw
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CountControl c=new CountControl(); p _[,P7
c.run(); FzEs1hpl
out.print(CountCache.list.size()+"<br>"); 9287&+,0r
%>