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~%
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CountBean.java ),}AI/j;zY
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/* "2ru 7Y"
* CountData.java $.%rAa_H
* Fg]?zEa
* Created on 2007年1月1日, 下午4:44 sBX-X$*N
* ^Q<mV*~
* To change this template, choose Tools | Options and locate the template under W i.5Y{
* the Source Creation and Management node. Right-click the template and choose t<iEj"5
* Open. You can then make changes to the template in the Source Editor. X;F8_+Np
*/ I^\&y(LJF
*XOJnyC_H
package com.tot.count; &EGqgNl
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/** w*9br SK
* |OO in]5
* @author WiL2
*/ lCd@jB{
public class CountBean { 5K%SL1N
private String countType; nuQ]8- ,
int countId; NE2pL@sk
/** Creates a new instance of CountData */ -_OS%ARa
public CountBean() {} &
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public void setCountType(String countTypes){ Elj_,z
this.countType=countTypes; {y= W6uP
} >4` dy
public void setCountId(int countIds){ w'4AJ Q|;
this.countId=countIds; :nN1e
} W*DVi_\$y
public String getCountType(){ =<@2#E)
return countType; !|waK~jK
} ?4H#G)F
public int getCountId(){ Z6C=T;w
return countId; @oP_;G
} #65^w=Sp}
} {@Yb%{+
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CountCache.java ~T7B$$
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/* {~GYj%-^
* CountCache.java Rgy-OA
* f>o,N{|
* Created on 2007年1月1日, 下午5:01 inb^$v
* 9I7\D8r
* To change this template, choose Tools | Options and locate the template under }GMbBZ:nKK
* the Source Creation and Management node. Right-click the template and choose ^jB8Q
* Open. You can then make changes to the template in the Source Editor. RrZM&lXY
*/ }kHdK vZ
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package com.tot.count; 1F8 W9b^D
import java.util.*; f"u*D,/sS
/** WO5O?jo'
* b3-eR5U/
* @author }TQ{`a@
*/ Am0{8
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public class CountCache { Qhi '')Q
public static LinkedList list=new LinkedList(); Y/<lWbj*A
/** Creates a new instance of CountCache */ '+>fFM,*B
public CountCache() {} F7L &=K$2y
public static void add(CountBean cb){ d6{Gt"
if(cb!=null){ f*{
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list.add(cb); sxKf&p;
} ?^mi3VM
} -~[9U,
} /^{BUo
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CountControl.java c\6+=\
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/* F;ZSzWq
* CountThread.java ,d+fDmm3
* WO4=Mte?
* Created on 2007年1月1日, 下午4:57 N /$`:8"
* _-!sBK+F
* To change this template, choose Tools | Options and locate the template under eivtH P
* the Source Creation and Management node. Right-click the template and choose Ma *y=d;,1
* Open. You can then make changes to the template in the Source Editor. z{"2S="
*/ lU^;Z6f
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package com.tot.count; jCAC
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import tot.db.DBUtils; ev0oO+u
import java.sql.*; iI@jZVk
/** "vYE+
* ,oxcq?7#4
* @author #*$P'r
*/ *%w69#D
public class CountControl{ (`>voi<^
private static long lastExecuteTime=0;//上次更新时间 w~_;yQ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 o@]So(9f
/** Creates a new instance of CountThread */ o*x*jn:hm
public CountControl() {} &Cim!I
public synchronized void executeUpdate(){ n%R;-?*v
Connection conn=null; FlfI9mm
PreparedStatement ps=null; zl-2$}<a
try{ cfox7FmW
conn = DBUtils.getConnection(); ]eQV,Vt
conn.setAutoCommit(false); {8,<ZZ_
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 5(W"-A}
for(int i=0;i<CountCache.list.size();i++){ YCe7<3> J4
CountBean cb=(CountBean)CountCache.list.getFirst(); TSAU?r\P
CountCache.list.removeFirst(); ^=n+T7"J
ps.setInt(1, cb.getCountId()); @D-AO_
ps.executeUpdate();⑴ GLn{s
//ps.addBatch();⑵ i&njqK!wS
} >-_d CNZ
//int [] counts = ps.executeBatch();⑶ F62V3 Xy
conn.commit(); IW8+_#d
}catch(Exception e){ y-p70.'{U
e.printStackTrace(); x\&`>>uA
} finally{ B/5=]R
try{ g-`~eG28D5
if(ps!=null) { Q9d`zR]
ps.clearParameters(); MS(JR
ps.close(); yKXff1^M
ps=null; e__@GBG
} ]sz3]"2
}catch(SQLException e){} <PPNhf8
DBUtils.closeConnection(conn); I/VxZ8T
} D'Z|}(d&
} BQcE9~H
public long getLast(){ ;U1UFqZ`
return lastExecuteTime; kyAXRwzI
} O3N0YGhJ
public void run(){ I$Qs;- (
long now = System.currentTimeMillis(); 5qg2Zc~
if ((now - lastExecuteTime) > executeSep) { +jg9$e "
//System.out.print("lastExecuteTime:"+lastExecuteTime); JOjoiA
//System.out.print(" now:"+now+"\n"); 5Zmw} M
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); oLWJm
lastExecuteTime=now; i{!T&8
executeUpdate(); xD&^j$Em
} Lb{e,JH
else{ *Ype>x{
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); @)kO=E d
} DjU9
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} hlu:=<B
} Xi?b]Z
//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 pE{yv1Yg
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类写好了,下面是在JSP中如下调用。 "#v=IJy&r
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<% 7iHK_\t n
CountBean cb=new CountBean(); 2L AYDaS
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); V`adWXu
CountCache.add(cb); h8\
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out.print(CountCache.list.size()+"<br>"); th6+2&B6
CountControl c=new CountControl(); Qn ^bVhG+
c.run(); o7B[R) 4
out.print(CountCache.list.size()+"<br>"); 5L:1A2Z?c
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