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: ]uJM6QuQ
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CountBean.java 78^Y;2 P]W
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/* SUSc
* CountData.java 0ZFB4GL
* O<Jwaap
* Created on 2007年1月1日, 下午4:44 i$g|?g~]
* fyGCfM
* To change this template, choose Tools | Options and locate the template under @<VG8{
* the Source Creation and Management node. Right-click the template and choose }1@n(#|c
* Open. You can then make changes to the template in the Source Editor. [6tR&D#K
*/ G@;Nz i89
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package com.tot.count; V_ {vZ/0e
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/** yi&?d&rK
* _y|[Z;
* @author AK%=DVkM
*/ 5~*=#v:`
public class CountBean { a_xQ~:H
private String countType; IBzHR[#,^
int countId; O5c_\yv=
/** Creates a new instance of CountData */ jDFp31_X
public CountBean() {} J,6!7a
public void setCountType(String countTypes){ ZyZl\\8U
this.countType=countTypes; KhLg*EL
} D1"1MUSod
public void setCountId(int countIds){ S|s3}]g9
this.countId=countIds; X"laZd947>
} (=6P]~,
public String getCountType(){ %+/f'6kR
return countType; xAFek;GY?
} NEZH<#
public int getCountId(){ I4A;
return countId; !2/l9SUi
} Cb+P7[X-
} `6dy
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CountCache.java Y#GT*V
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/* J!ln=h
* CountCache.java |Tj`qJGVw
* L;L2j&i%v)
* Created on 2007年1月1日, 下午5:01 9Kq<\"7Bmz
* ?<-wHj)
* To change this template, choose Tools | Options and locate the template under Y=PzN3
* the Source Creation and Management node. Right-click the template and choose y-D>xV)n
* Open. You can then make changes to the template in the Source Editor. L;
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*/ F%w\D9+P
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package com.tot.count; e-&L\M
import java.util.*; JkRGt Yq
/** <m-Ni
* k*A4;Bm
* @author k?!TjBKm
*/ *'kC8ZR5
public class CountCache { /W7&U
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public static LinkedList list=new LinkedList(); rGQ86L<
/** Creates a new instance of CountCache */ 3 (Gygq#
public CountCache() {} ddGkk@CA
public static void add(CountBean cb){ O8!!UA8V
if(cb!=null){ 8JQ<LrIt9
list.add(cb); }M;sz
} _SU,f>
} lr)G:I#|
} h #$_<U
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CountControl.java 37.)@
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/* {jq^hM!TEy
* CountThread.java ^!zJf7(+<>
* R4hav
* Created on 2007年1月1日, 下午4:57 7Y| Wy
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* * fOS"-CL
* To change this template, choose Tools | Options and locate the template under }W^V^i )
* the Source Creation and Management node. Right-click the template and choose g)2m$#T&s
* Open. You can then make changes to the template in the Source Editor. Fj[ dO&
*/ Lh8#I&x
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package com.tot.count; p\4h$."
import tot.db.DBUtils; Br_3qJNVP
import java.sql.*; 2b{@]Fp
/** q>Dr)x)
* TXY
* @author WV9[DFU
*/ t!+%g) @
public class CountControl{ [ni-UNTv
private static long lastExecuteTime=0;//上次更新时间 @y&h4^)z
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 [346w
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/** Creates a new instance of CountThread */ Th I
public CountControl() {} $~;6 hnrm
public synchronized void executeUpdate(){ _R>s5|_
Connection conn=null; Y9lbf_51
PreparedStatement ps=null; *,Aa9wa{
try{ ;h*"E(Pp
conn = DBUtils.getConnection(); )o}=z\M-bN
conn.setAutoCommit(false); NK*:w *SOI
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); VLl&>Pbe-
for(int i=0;i<CountCache.list.size();i++){ \!?
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CountBean cb=(CountBean)CountCache.list.getFirst(); URj%
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CountCache.list.removeFirst(); hfP(N_""S
ps.setInt(1, cb.getCountId()); VH$\ a~|
ps.executeUpdate();⑴ )^QG-IM
//ps.addBatch();⑵ F~11 _
} Au\=ypK
//int [] counts = ps.executeBatch();⑶ {d{WMq$
conn.commit(); am)J'i,
}catch(Exception e){ j$JV(fz
e.printStackTrace(); jHUz`.8B
} finally{ :Kt mSY
try{ }J4BxBuV8
if(ps!=null) { 1bFEx_
ps.clearParameters(); Hf`&&
ps.close(); k_.j%
ps=null; tL|L"t_5x
} p]J]<QaZD
}catch(SQLException e){} Cys/1DkE
DBUtils.closeConnection(conn); sIQMUC[!
} 0Zp<=\!;
} .WPuQZ!
public long getLast(){ )Uoe~\
return lastExecuteTime; a'L7y%
} dnhpWVhn
public void run(){ :7'0:'0$t
long now = System.currentTimeMillis(); j+ T\c2d
if ((now - lastExecuteTime) > executeSep) { T!O3(
//System.out.print("lastExecuteTime:"+lastExecuteTime); cmC&s'/8`D
//System.out.print(" now:"+now+"\n"); QRn:=J%W W
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 0[3tW[j
lastExecuteTime=now; s^x ,S
executeUpdate(); *jqPKK/
} jAK`96+D~b
else{ \)s 3]/"7
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); r]K0
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} 9EY_R&Yq%
} >LRaIU>
} vzgudxG'z
//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 pQ6t]DJ4
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类写好了,下面是在JSP中如下调用。 %%H. &*i,
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<% !15@M|,OL
CountBean cb=new CountBean(); !IrKou)/_
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 5juCeG+Z
CountCache.add(cb); Kk"B501
out.print(CountCache.list.size()+"<br>"); TQyFF/K
CountControl c=new CountControl(); |cBF-KNZ
c.run(); w{UKoU
out.print(CountCache.list.size()+"<br>"); u9[w~U#
%>