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: y=5s~7]
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CountBean.java N7}.9%EV
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/* !t~S.`vF
* CountData.java 3vNo D
* |2{y'?,
* Created on 2007年1月1日, 下午4:44 @x"vGYKd
* LnrR#fF]Z
* To change this template, choose Tools | Options and locate the template under $&k zix
* the Source Creation and Management node. Right-click the template and choose vL\wA_z"<H
* Open. You can then make changes to the template in the Source Editor. XSn^$$S
*/ e!G
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package com.tot.count; *sZOws<
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/** mcp}F|ws
* aq,&W
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* @author <iJ->$
*/ )#IiHBF
public class CountBean { xREqcH,vU
private String countType; @6}c\z@AxM
int countId; 0@^YxU[YN
/** Creates a new instance of CountData */ kM]?
public CountBean() {} XvZg!<*OH
public void setCountType(String countTypes){ s26:(J
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this.countType=countTypes; 9IC"p<D
} )uZ<?bkQ
public void setCountId(int countIds){ >vt#,8VAN
this.countId=countIds; sAC1Pda
} @&mv4zz&W
public String getCountType(){ "7Zb)Ocb
return countType; %HwPOEJ
} 'hf-)\Ylf
public int getCountId(){ yi
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return countId; {C|#<}1
} ZMy7z|
} %+Mi~k*A'
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CountCache.java iV(B0z
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/* +cQ4u4
* CountCache.java u5$\E]+_
* >77
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* Created on 2007年1月1日, 下午5:01 u23^* -
* 6>SP5|GG
* To change this template, choose Tools | Options and locate the template under lmQ!q>N
* the Source Creation and Management node. Right-click the template and choose M2%<4(UwI
* Open. You can then make changes to the template in the Source Editor. ]^/:Xsk$
*/ E/Eny5
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package com.tot.count; 2
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import java.util.*; ZTMzL%i
/** EX=+TOkAf
* 6=MejT
* @author P[%
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*/ 86vk"
public class CountCache { Rfeiv
public static LinkedList list=new LinkedList(); k "'q
/** Creates a new instance of CountCache */ dxUq5`#G,
public CountCache() {} zp,f}
public static void add(CountBean cb){ u}qfwVX Z
if(cb!=null){ DIkD6n?V
list.add(cb); 91jv=>=DM
} P/,7CfyPd
} nBWrkVX
} ?U iwr{Q
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CountControl.java V.: a6>]
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/* ]J5[ZVz
* CountThread.java it D%sKo
* `i,ZwnLh{
* Created on 2007年1月1日, 下午4:57 KFCuv15w,3
* ORp6
* To change this template, choose Tools | Options and locate the template under ZgZ}^x
* the Source Creation and Management node. Right-click the template and choose ]cLpLA"
* Open. You can then make changes to the template in the Source Editor. Tf21K9+`L
*/ )p(5$AR7
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package com.tot.count; K>,Kbs=D6
import tot.db.DBUtils; Bl3G_Ep
import java.sql.*; 2fFNJ
/** Q^b_+M
* 9Rb-QI
* @author !M)!
*/ iG6 ^s62z7
public class CountControl{ /^P^K
private static long lastExecuteTime=0;//上次更新时间 ;!Ojb
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 X+?*Tw!\
/** Creates a new instance of CountThread */ B#B$w_z
public CountControl() {} F,%qG,
public synchronized void executeUpdate(){ zTAt% w5
Connection conn=null; `a3q)}*Y
PreparedStatement ps=null; %*oz~,i
try{ bxqXFy/I
conn = DBUtils.getConnection(); F2AM/m^!q
conn.setAutoCommit(false); +}I[l,,xy
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 43A6B
for(int i=0;i<CountCache.list.size();i++){ .hSacd
CountBean cb=(CountBean)CountCache.list.getFirst(); &z
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CountCache.list.removeFirst(); xQk]a1
ps.setInt(1, cb.getCountId()); -]+XTsL
ps.executeUpdate();⑴ 7h&$^
//ps.addBatch();⑵ 818</b<yn
} .gG<08Z
//int [] counts = ps.executeBatch();⑶ agM.-MK
conn.commit(); slOki|p;
}catch(Exception e){ 1AjsAi,7;2
e.printStackTrace(); (+>+@G~o
} finally{ C ])Q#!D|
try{ {5#P1jlT
if(ps!=null) { dY;^JPT
ps.clearParameters(); -EF(J
ps.close(); $io-<Z#Q
ps=null; TEh]-x`
} LCyci1\@
}catch(SQLException e){} \&&kUpI
DBUtils.closeConnection(conn); 23_<u]V
} x98LOO
} e,Gv~ae9
public long getLast(){ G"5Nj3vd
return lastExecuteTime; w>IkC+.?
} Q2Yv8q_}Uq
public void run(){ &A*oQ3
long now = System.currentTimeMillis(); -=Q_E^'
if ((now - lastExecuteTime) > executeSep) { S/G,A,"c
//System.out.print("lastExecuteTime:"+lastExecuteTime); U^+9l?ol
//System.out.print(" now:"+now+"\n"); ?"{+m
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ga4 gH>4
lastExecuteTime=now; h$f/NSct2
executeUpdate(); Mpk^e_9`<
} #E{aN?_
else{ 6mep|![6
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); bhOyx
} oeDsJ6;
} r{YyKSL1*K
} L`R,4mI.W
//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 vk5pnCM^3
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类写好了,下面是在JSP中如下调用。 T!"<Kv]J
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<% ^n@iCr9
CountBean cb=new CountBean(); 8!VjXj"
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); r[TS#hQ
CountCache.add(cb); /I7sa* i
out.print(CountCache.list.size()+"<br>"); T9t9])
CountControl c=new CountControl(); q[M7)-
c.run(); d#ya"e>
out.print(CountCache.list.size()+"<br>"); 0Y)b319B
%>