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: fL2P6N@
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CountBean.java x!GDS>
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/* PM84Z@Y
* CountData.java mU4(MjP?
* Zb1GR5MB`k
* Created on 2007年1月1日, 下午4:44 }XBF#BN
* C%yH}T\s
* To change this template, choose Tools | Options and locate the template under GW>F:<p
* the Source Creation and Management node. Right-click the template and choose =A6*;T"W
* Open. You can then make changes to the template in the Source Editor. np^&cY]
*/ S&UP;oc
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package com.tot.count; Lf%3-P
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/** }V]b4t
* 9)tb=
* @author Xf&YcHo
*/ :} =lE"2
public class CountBean { ]}/Rl}_
private String countType; fu\j
int countId; x*z[(0g!
/** Creates a new instance of CountData */ moxmQ>xoH
public CountBean() {} tjThQ
public void setCountType(String countTypes){ ~2rQ80_
this.countType=countTypes; >|%3j,<U
} kNWTM%u9
public void setCountId(int countIds){ e+BZoK ^
this.countId=countIds; ?=Ceo#Er
} "W+>?u )
public String getCountType(){ #^VZJ:2=|
return countType; iqB5h|
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} bh5D}w
public int getCountId(){ z#&1>
return countId; "v?F4&\ 8
} :u9'ZHkZ
} nQV0I"f]?]
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CountCache.java W6>t!1oO+
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/* rVP\F{Q4Tr
* CountCache.java *CXc{{
* 8:c=h/fa
* Created on 2007年1月1日, 下午5:01 grE(8M
* -B-G$ii
* To change this template, choose Tools | Options and locate the template under t!3s@
* the Source Creation and Management node. Right-click the template and choose ~3M4F^
* Open. You can then make changes to the template in the Source Editor. 2LN6pu
*/ G 3U[)("
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package com.tot.count; }.045 Wuu
import java.util.*; 4r4 #u'Om
/** RN 4?]8
* >z%YKdq
* @author N,lr~6)
*/ o#6QwbU25
public class CountCache { .g}N@
public static LinkedList list=new LinkedList(); 8>WA5:]v
/** Creates a new instance of CountCache */ IH=$
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public CountCache() {} BAXu\a-C_
public static void add(CountBean cb){ hO[_ _j8
if(cb!=null){ {Ni]S$7
list.add(cb); )rP,+ B?W
} swZi
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} uz+WVmb
} A^FkU
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CountControl.java KF#^MEw%
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/* O^CBa$
* CountThread.java 4>oM5Yf8
* (${:5W
* Created on 2007年1月1日, 下午4:57 }*rS g .
* tnUfi8\ob
* To change this template, choose Tools | Options and locate the template under Vx.c`/
* the Source Creation and Management node. Right-click the template and choose ?"
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* Open. You can then make changes to the template in the Source Editor. >)C7IQ/
*/ |U1 [R\X
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package com.tot.count; ^@8XJ[C,_
import tot.db.DBUtils; #tA9`!
import java.sql.*; c-JXWNz
/** I,#E`)
* UfPB-EFl$D
* @author f_O|
*/ ,N:^4A
public class CountControl{ bC+ZR{M
private static long lastExecuteTime=0;//上次更新时间 :Ef!gpS}?R
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ($`IHKF1.l
/** Creates a new instance of CountThread */ `q]' ^EzJ
public CountControl() {} 9Br+]F_i
public synchronized void executeUpdate(){ @d{}M)6\!
Connection conn=null; GC# [&>L
PreparedStatement ps=null; Q 8Ek}O\MC
try{ 2~/`L=L
conn = DBUtils.getConnection(); ):hz/vZ
conn.setAutoCommit(false); Z?xaXFm_
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); =7TWzUCO#
for(int i=0;i<CountCache.list.size();i++){ X\!q8KEpR&
CountBean cb=(CountBean)CountCache.list.getFirst(); 1J1Jp|j.
CountCache.list.removeFirst(); {J1rjrPo
ps.setInt(1, cb.getCountId()); KB~1]cYMp
ps.executeUpdate();⑴ :_i1gY)
//ps.addBatch();⑵ I`XOvSO
} !QAndg{;D
//int [] counts = ps.executeBatch();⑶ 0^Ldw)C"
conn.commit(); YIW9z{rrs
}catch(Exception e){ HLz<C
e.printStackTrace(); z)KoK`\mE"
} finally{ r)>'cjx/
try{ 6[XaIco=C
if(ps!=null) { QE"$Lc)
ps.clearParameters(); ,9^ 5
ps.close(); .T8^>z1/\F
ps=null; YhglL!pC
} w7~]c,$y.
}catch(SQLException e){} h{-en50tN
DBUtils.closeConnection(conn); Bi fI.2|
} +e>G V61
} (421$w,B%
public long getLast(){ o"RE4s\G~r
return lastExecuteTime; @Z$fEG)9
} J%ws-A?6rN
public void run(){ @.cord`
long now = System.currentTimeMillis(); H4v%$R;K
if ((now - lastExecuteTime) > executeSep) { n}Thc6f3D
//System.out.print("lastExecuteTime:"+lastExecuteTime); n3J,`1*ct
//System.out.print(" now:"+now+"\n"); :W&klUU"
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 24InwR|^
lastExecuteTime=now; >/.jB/q
executeUpdate(); G2[2y-Rv
} P
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else{ yT3K 2A
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); _kOuD}_|
} u(r
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} 2mj>,kS?c
} 7m8:odeF
//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 =fBr2%qK
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类写好了,下面是在JSP中如下调用。 ZKI` ;
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<% *sfz+8Y
CountBean cb=new CountBean(); )CL/%I,^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 'uUa|J1mu
CountCache.add(cb); IMSm
out.print(CountCache.list.size()+"<br>"); .
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CountControl c=new CountControl(); F r2
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c.run(); ,,9vk \
out.print(CountCache.list.size()+"<br>"); }?{. 'Hv0
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