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: {{c/:FTEU
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CountBean.java ^YddVp
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/* nPp\IE}:
* CountData.java 3 8>?Z]V
* 6/ir("LK
* Created on 2007年1月1日, 下午4:44 fD3}s#M*G
* pp$WM\r
* To change this template, choose Tools | Options and locate the template under {_0m0
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* the Source Creation and Management node. Right-click the template and choose XK[cbVu
* Open. You can then make changes to the template in the Source Editor. V @A+d[
*/ 0xbx2jlkY
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package com.tot.count; g9>
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/** p._BG80
* \ct) /
* @author >p4#AfGF
*/ 6/`$Y!.ub
public class CountBean { 5z8CUDt
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private String countType; km1{Oh
int countId; Mg?^ 5`*
/** Creates a new instance of CountData */ cd1M0z
public CountBean() {} +}H2|vP
public void setCountType(String countTypes){ 4G`7]<
this.countType=countTypes; MP/6AAt7=|
} hGmJG,H
public void setCountId(int countIds){ + yX\!H"
this.countId=countIds; ". jY3<bQg
} %Q:i6 ~
public String getCountType(){ lhsd39NM
return countType; qLkn a
} {2<A\nW
public int getCountId(){ i$HA@S
return countId; 7'pCFeA>=T
} 5y07@x
} e;KZTH;
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CountCache.java Ei!5Qya>
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/* *sI`+4h[
* CountCache.java 5~Vra@iab:
* smEKQHB
* Created on 2007年1月1日, 下午5:01 X]6Hgz66
* j)IXe 0dMC
* To change this template, choose Tools | Options and locate the template under B WdR~|2
* the Source Creation and Management node. Right-click the template and choose rbl EyCR
* Open. You can then make changes to the template in the Source Editor. o~7~S
*/ l$KC\$?%*
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package com.tot.count; v;.7-9c*
import java.util.*; fY3^L"R
/** +Bk d
* #$p&J1
* @author >r+Dl\R
*/ g.yr)
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public class CountCache { \6A-eWIQif
public static LinkedList list=new LinkedList(); Oga/
/** Creates a new instance of CountCache */ p/jC}[$v
public CountCache() {} #"{wm
public static void add(CountBean cb){ %00KOM:
if(cb!=null){ 0M^7#),
list.add(cb); 5Ug.J{d
} 2QwdDKMS_
} }Z5f5q
} WW33ZJ
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CountControl.java 5U)Ia>p
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/* oujg(
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* CountThread.java Fj? Q4_
* ,PH ;j_
* Created on 2007年1月1日, 下午4:57 +"1@6,M
* $#R@x.=
* To change this template, choose Tools | Options and locate the template under sPMCN's
* the Source Creation and Management node. Right-click the template and choose ~DYUI#x
* Open. You can then make changes to the template in the Source Editor. \;&WF1d`ac
*/ T,z7U2O
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package com.tot.count; E=
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import tot.db.DBUtils; xgsE JE
import java.sql.*; CUIFKM
/** dk<) \C"
* (^h2'uB
* @author `h%(ZG~
*/ jVA|Vi_2
public class CountControl{ ?@n,
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private static long lastExecuteTime=0;//上次更新时间 =$kSvCjP
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 !2YvG%t^6
/** Creates a new instance of CountThread */ -8Z;s8ACo
public CountControl() {} B=vBJC)
public synchronized void executeUpdate(){ ,O`a_b]
Connection conn=null; [S Jx\Os
PreparedStatement ps=null; cp| q
try{ fXo$1!
conn = DBUtils.getConnection(); EV=/'f[++
conn.setAutoCommit(false); H3Ws$vl9n
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 4i]h0_]
for(int i=0;i<CountCache.list.size();i++){ *;E\,,Io
CountBean cb=(CountBean)CountCache.list.getFirst(); [2*?b/q3J
CountCache.list.removeFirst(); TwdY6E3`
ps.setInt(1, cb.getCountId()); 0j\} @
ps.executeUpdate();⑴ (FVHtZi7
//ps.addBatch();⑵ zDD
} G;jX@XqZ
//int [] counts = ps.executeBatch();⑶ &9j*Y
conn.commit(); JE~;gz]
}catch(Exception e){ ?^}
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e.printStackTrace(); V*d@@%u**
} finally{ z^,P2kqK_
try{ NCX`-SLv
if(ps!=null) { %(}%#-X
ps.clearParameters(); *8% nbR
ps.close(); ;owU]Xk%8K
ps=null; (F+]h]KSi
} 8-5g6qAS
}catch(SQLException e){} 'hNRIM1
DBUtils.closeConnection(conn); j=kz^o~mH
} 4R}$P1 E
} #&sw%CD
public long getLast(){ $?*XPzZ
return lastExecuteTime; /A82~
} 8+mu'RZ X
public void run(){ INNTp[
long now = System.currentTimeMillis(); BbG=vy8'l
if ((now - lastExecuteTime) > executeSep) { F9J9zs*,
//System.out.print("lastExecuteTime:"+lastExecuteTime); *r/o
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//System.out.print(" now:"+now+"\n"); n2N:rP
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 3kW%,d*_
lastExecuteTime=now; /St d6B*
executeUpdate(); ' JAcN@q~z
} _]Y9Eoz
else{ {fxytiH8
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); cnL@j_mb
} zlhU[J}"1|
} _edT+r>+
} )U+Pt98"
//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 )YPut.
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类写好了,下面是在JSP中如下调用。 9xRor<
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<% XQStlUw8+
CountBean cb=new CountBean(); ? oQ_qleuo
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0czEA
CountCache.add(cb); *n*po.Xr
out.print(CountCache.list.size()+"<br>"); D.,~I^W
CountControl c=new CountControl(); 8z`Ne(h;
c.run(); J%1 2Ey@6
out.print(CountCache.list.size()+"<br>"); t}fU 2Yb
%>