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: @A6\v+ih
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CountBean.java J`O4]XRY
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/* ]Bs ?
* CountData.java OgrUP
* .i/]1X*;r^
* Created on 2007年1月1日, 下午4:44 o})4Jt1vj
* +byw*Kk
* To change this template, choose Tools | Options and locate the template under i{VjSWq
* the Source Creation and Management node. Right-click the template and choose 0+8ThZ?n
* Open. You can then make changes to the template in the Source Editor. p;j$i6YJ
*/ .c"UlOZ&w^
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package com.tot.count; ywk;
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/** )+ Wr- Yay
* vD) LRO
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* @author )1j~(C)E8
*/ -baGr;,Cu
public class CountBean { 5%?La`C9[
private String countType; &tD`~
int countId;
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/** Creates a new instance of CountData */ ^V_acAuS^
public CountBean() {} @D"#B@j
public void setCountType(String countTypes){ D5T\X-+]O
this.countType=countTypes; p/lMv\`5
} lIzJO$8cM
public void setCountId(int countIds){ 5vbnO]8
this.countId=countIds; (L|SE4
} FPMhHHM
public String getCountType(){ =JO|m5z8>
return countType; :v{$]wg
} /l+x&xYD
public int getCountId(){ 6{azzk8
return countId; h#]}J}si
} DGHX:Ft#
} %/etoK
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CountCache.java AV d
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/* 4N$svA
* CountCache.java ^ ?tAt3dMI
* nZ\,ZqV
* Created on 2007年1月1日, 下午5:01 ;%dkwKO
* 9d[0i#` :q
* To change this template, choose Tools | Options and locate the template under 0E\R\KO$>
* the Source Creation and Management node. Right-click the template and choose yH#;k:O=
* Open. You can then make changes to the template in the Source Editor. ]; ^OY\,
*/ QwT]|
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package com.tot.count; M5ZWcD.1
import java.util.*; 'hya#rC&(
/** Z7.)[
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* "E''ZBLO~
* @author ejr"(m(Xe
*/ [0 &Lvx
public class CountCache { C4 Wdt
public static LinkedList list=new LinkedList(); 3lL:vD5(
/** Creates a new instance of CountCache */ lC_zSmT
public CountCache() {} uqQMS&;+,|
public static void add(CountBean cb){ =dA T^e##
if(cb!=null){ }7.q[ ^oF
list.add(cb); ~-:CN(U
} iT5H<uS
} HqF8:z?v
} M9&tys[ KX
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CountControl.java 4l$8lYi
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/* +z[!]^H]4
* CountThread.java \FKIEg+(2
* %[Ds-my2
* Created on 2007年1月1日, 下午4:57 bZG$ biq
* X4k/7EA
* To change this template, choose Tools | Options and locate the template under aZ0H)
* the Source Creation and Management node. Right-click the template and choose @B^'W'&C
* Open. You can then make changes to the template in the Source Editor. ffB]4
*/ C,<TAm
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package com.tot.count; Bhs`Y/Ls-
import tot.db.DBUtils; ]_pL79y
import java.sql.*; d:wAI|
/** s24H.>Z
* U)PumU+z$u
* @author =|#-Rm^YB
*/ ;C{_T:LS
public class CountControl{ ueg X
private static long lastExecuteTime=0;//上次更新时间 }I10hy~W
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 5 O6MI4:
/** Creates a new instance of CountThread */ mzw*6e2T
public CountControl() {} :_H88/?RR
public synchronized void executeUpdate(){ a,E;R$[!
Connection conn=null; A+l"
PreparedStatement ps=null; JQ1VCG
try{ ;8v5 qz
conn = DBUtils.getConnection(); Wm,,OioK
conn.setAutoCommit(false); #RD%GLY
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); `^}9= Q'r
for(int i=0;i<CountCache.list.size();i++){ <>:kAT,sP
CountBean cb=(CountBean)CountCache.list.getFirst(); HkN +:
CountCache.list.removeFirst(); BY d3 rI
ps.setInt(1, cb.getCountId()); +vnaEy
ps.executeUpdate();⑴ o MAK[$k;
//ps.addBatch();⑵ h`Mf;'P
} L!G3u/
//int [] counts = ps.executeBatch();⑶ QM]^@2rK2
conn.commit(); dWUu3
}catch(Exception e){ G~]BC#nB_
e.printStackTrace(); |eqDT,4
} finally{ AK!G#ug
try{
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if(ps!=null) { -5[GX3h0
ps.clearParameters(); WDZi
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ps.close(); ;1 fM L,8
ps=null; ivq4/Y]-X
} <b\urtoJ
}catch(SQLException e){} rij[ZrJ
DBUtils.closeConnection(conn); ^PI49iB
} x,%&[6(
} GM/1ufZH
public long getLast(){ hTm}j,H
return lastExecuteTime; 4l*&3Ar
} cPbz7
public void run(){ 8{YxUD
long now = System.currentTimeMillis(); 1 W u
if ((now - lastExecuteTime) > executeSep) { ?2TH("hV$
//System.out.print("lastExecuteTime:"+lastExecuteTime); hA8 zXk/'8
//System.out.print(" now:"+now+"\n"); !iw
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); UU;:x"4
lastExecuteTime=now; :9b RuUm
executeUpdate(); ||V:',#,W
} kXr%73s
else{ +0 MKh
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); vF&b|V+,
} I,eyL$x
} z@i4dC
} P]B#i1
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 ^U}0D^jDeE
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类写好了,下面是在JSP中如下调用。 L
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<% R5"p7>
CountBean cb=new CountBean(); ,k!a3"4+TJ
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 7&4,',0VL
CountCache.add(cb); }H=OVbQor
out.print(CountCache.list.size()+"<br>"); !U_L7
CountControl c=new CountControl(); Kcl$|T
c.run(); Bv8C_-lV/
out.print(CountCache.list.size()+"<br>"); %S.U`(.
%>