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: )FP|}DCxQ
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CountBean.java V":BAn
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/* I45A$nV#Q
* CountData.java k`t'P6
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* ceOjuzY
* Created on 2007年1月1日, 下午4:44 ^AM_A>HnG
* :b>|U"ux
* To change this template, choose Tools | Options and locate the template under q5A+%#
* the Source Creation and Management node. Right-click the template and choose B -KOf
* Open. You can then make changes to the template in the Source Editor. -{wuF0f
*/ 79V5{2Y*U
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package com.tot.count; zm:=d>D..
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/** =?lT&|"
* <_>6a7ra
* @author MT5A%|H e
*/ d{he
public class CountBean { EH:1Z*|Z{\
private String countType; q^cF D
int countId; C0W~Tk\C2
/** Creates a new instance of CountData */ v Y\O=TZT
public CountBean() {} |x4yPYBL
public void setCountType(String countTypes){ [vi4,'wm
this.countType=countTypes; Po_OQJ:bd
} <7 rK
public void setCountId(int countIds){ LJ))
this.countId=countIds; )L!R~F
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}
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public String getCountType(){ cg.e(@(
return countType; $SXxAS1
} I5A^/=bf&
public int getCountId(){ 10rGA=x'(
return countId; b>z.d-
} s`J=:>9*
} e^GW[lT
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CountCache.java 9H}&Ri%
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/* V[M#qZS
* CountCache.java acZHb[w
* l!y
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* Created on 2007年1月1日, 下午5:01 M;Rw]M
* (0Qq rNs
* To change this template, choose Tools | Options and locate the template under J9FNjM[qe
* the Source Creation and Management node. Right-click the template and choose 5jQP"^g
* Open. You can then make changes to the template in the Source Editor. Fdw[CYHz
*/ ."X~?Nk
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package com.tot.count; 2P
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import java.util.*; >>cd3)b
/** h6e$$-_
* \.a .'l
* @author EAB+kY
*/ K)+l 6Q
public class CountCache { ?GarD3#A
public static LinkedList list=new LinkedList();
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/** Creates a new instance of CountCache */ 3R*@m
public CountCache() {} X-,y[ )
public static void add(CountBean cb){ LwPM7S~ *
if(cb!=null){ cv4M[]U~
list.add(cb); 2S6EDXc
} =.oWg uzu
} ws?s
} I0vnd7
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CountControl.java @>IjfrjV
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/* FBAC9}V"
* CountThread.java emB D@r
* kV3j}C"
* Created on 2007年1月1日, 下午4:57 uW~,H}E
* x2sOEkcQ
* To change this template, choose Tools | Options and locate the template under bJF/daC5
* the Source Creation and Management node. Right-click the template and choose .4W>9
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* Open. You can then make changes to the template in the Source Editor. P i!r}m
*/ )hW {>Y3x
}.) 43(>]
package com.tot.count; 4_I{Q^f
import tot.db.DBUtils; d`<^+p)oy
import java.sql.*; =k=2~
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/** YiuOu(X
* pf@}4PN}
* @author *.c9$`s
*/ (I
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public class CountControl{ K=?F3tX^
private static long lastExecuteTime=0;//上次更新时间 ]C6[`WF
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 idS
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/** Creates a new instance of CountThread */ QeJ.o.m{
public CountControl() {} _1> 4Q%
public synchronized void executeUpdate(){ }!]x|zU.=
Connection conn=null; yO;C3q
PreparedStatement ps=null; ENWB|@B
try{ wV&f|JO0+
conn = DBUtils.getConnection(); doO
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conn.setAutoCommit(false); <lmJa#
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ZV]e-
for(int i=0;i<CountCache.list.size();i++){ ,(27p6!
CountBean cb=(CountBean)CountCache.list.getFirst(); ~!-8l&C
CountCache.list.removeFirst(); >DUE8hp;<
ps.setInt(1, cb.getCountId()); Hq\E06S@
ps.executeUpdate();⑴ M|#5gKXd
//ps.addBatch();⑵ Z) i1?#
} ([CnYv
//int [] counts = ps.executeBatch();⑶ x<j"DS}S)D
conn.commit(); ?U/Wio$@
}catch(Exception e){ `6N-MsP
e.printStackTrace(); XQJ^)d00h
} finally{ u%1k
try{ 8C,utjy
if(ps!=null) { ObyuhAR
ps.clearParameters(); ho]!G498
ps.close(); MupW=3.38
ps=null; C$td{tM
} hJo^Wo
}catch(SQLException e){} VUC <0WV
DBUtils.closeConnection(conn); ^GrkIh0nL
} E'^]zW=9
} #O9*$eMw
public long getLast(){ k\c &2T]W
return lastExecuteTime; EcU'*
} -iDEh_pts
public void run(){ b({Nf,(a2
long now = System.currentTimeMillis(); RD$tc~@UB
if ((now - lastExecuteTime) > executeSep) { >@^yj+k
//System.out.print("lastExecuteTime:"+lastExecuteTime); 7vpN6YP
//System.out.print(" now:"+now+"\n"); -j`!(IJ
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Wbn[Q2h5
lastExecuteTime=now; (OyY_`
executeUpdate(); f >)Tq'
} QPe9s[Y
else{ ]fADaw-R
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); .5!sOOs$P
} %- ZR~*
} mbX)'. +L
} E/7vIg
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//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 qbU1qF/
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类写好了,下面是在JSP中如下调用。 ]opW; |{e
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<% [CDX CV-z
CountBean cb=new CountBean(); hX8gV~E=y
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 1t[;` iZ
CountCache.add(cb); xZP >g
out.print(CountCache.list.size()+"<br>"); bwSRJFqb
CountControl c=new CountControl(); 5hJYy`h~
c.run(); @4_rx u&
out.print(CountCache.list.size()+"<br>"); =(.mf
%>