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: >_o_&;=`v
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CountBean.java Je'$V%{E
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/* ?$?Ni)Z
* CountData.java 4d#W[
* "](~VF[J8
* Created on 2007年1月1日, 下午4:44 XxGm,A+>Ty
* g!8-yri
* To change this template, choose Tools | Options and locate the template under 9}=Fdt
* the Source Creation and Management node. Right-click the template and choose `fH6E8N
* Open. You can then make changes to the template in the Source Editor. lyyi?/W%
*/ cG<?AR?wDT
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package com.tot.count; ci!c7 ,'c
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/** b% F|VG
* 5Z@Q^
* @author !@Ox%vK
*/ T|u)5ww%
public class CountBean { {0|^F!1z
private String countType; 1@am'#<
int countId; @M1U)JoQ
/** Creates a new instance of CountData */ 5b&'gd^d
public CountBean() {} UwLa9Dn^
public void setCountType(String countTypes){ *+ 7#z;
this.countType=countTypes; ;y"DEFs,u
} )3 ;S;b
public void setCountId(int countIds){ "m!Cl-+u
this.countId=countIds; lHx$F?
} *ce h
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public String getCountType(){ $ZA71TzMV
return countType; +iXA|L9=
} 5yry$w$G)
public int getCountId(){ <+6)E@Y
return countId; "G<^@v9
} ^P[-HA|
} p%}oo#%J
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CountCache.java *_ "j"{
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/* $zJ.4NA
* CountCache.java )msqt!Ev
* :5ji.g* 0
* Created on 2007年1月1日, 下午5:01 r!;NH3 *
* x{=ty*E
* To change this template, choose Tools | Options and locate the template under +;vfn>^!b
* the Source Creation and Management node. Right-click the template and choose /V,:gLpQ
* Open. You can then make changes to the template in the Source Editor. smSUo/
*/ SW bwD/SN
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package com.tot.count; uoF9&j5E@Z
import java.util.*; U5" C"+
3
/** o0AREZ+I
* *dGW=aM#C
* @author N/Z<v* i"
*/ =l
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public class CountCache { }v`5
public static LinkedList list=new LinkedList(); Oq[tgmf
/** Creates a new instance of CountCache */ aaLT%
public CountCache() {} q$K^E
public static void add(CountBean cb){ PQ1\b-I
if(cb!=null){ .Zo8KwkFY
list.add(cb); Zd042
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} MwiT1sB~
} ^"l4
} I"r*p?
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CountControl.java dqcfs/XhP
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/* r6"t`M
* CountThread.java PX+$Us
* z1s9[5
* Created on 2007年1月1日, 下午4:57 x#U?~6.6
* WG9x_X&XJ
* To change this template, choose Tools | Options and locate the template under zDC-PHFHQ
* the Source Creation and Management node. Right-click the template and choose rqifjsv
* Open. You can then make changes to the template in the Source Editor. s<n5^Vxy
*/ [5>0om5
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package com.tot.count; ^ygN/a>rr
import tot.db.DBUtils; hV_0f_Og
import java.sql.*; 9^XT,2Wwf
/** zcDVvP
* st~f}w@
* @author 7R ;!
*/ Wo\NX05-?
public class CountControl{ (C1]R41'
private static long lastExecuteTime=0;//上次更新时间 "QA!z\0\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 5ZUqCl(PX)
/** Creates a new instance of CountThread */ wtaeF+u-R-
public CountControl() {} 7h,SX]4Q
public synchronized void executeUpdate(){ "|(+~8[
Connection conn=null; I@e{>}
PreparedStatement ps=null; a,!c6'QE
try{ )~s(7
4`}
conn = DBUtils.getConnection(); a~WtW]
conn.setAutoCommit(false); c1Xt$[_
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ! p458~|
for(int i=0;i<CountCache.list.size();i++){ qa2QS._m
CountBean cb=(CountBean)CountCache.list.getFirst(); }3ty2D#/:
CountCache.list.removeFirst(); .(ki(8Z N
ps.setInt(1, cb.getCountId()); EX=Q(} 9F<
ps.executeUpdate();⑴ u9_ Fjm}&
//ps.addBatch();⑵ UJ2Tj+
} g#W )EXUR
//int [] counts = ps.executeBatch();⑶ v~9PS2
conn.commit(); >}Za)
}catch(Exception e){ O$<kWSC
e.printStackTrace(); BNnGtVAbZ
} finally{ R=xT \i{4h
try{ S!0<aFh
if(ps!=null) { ==~X8k|{E
ps.clearParameters(); hVd%
jU:
ps.close(); {b}Ri&oEOH
ps=null; ^F/N-!}q
} +<(N]w*
}catch(SQLException e){} D`V03}\-
DBUtils.closeConnection(conn); k& 2U&
} -$>R;L
} ^/U-(4O05*
public long getLast(){ Y7{IF X
return lastExecuteTime; q",n:=PL
} g kT`C
public void run(){ /q0[T{Wz$
long now = System.currentTimeMillis(); #"|</*%>
if ((now - lastExecuteTime) > executeSep) { !"Jne'f
//System.out.print("lastExecuteTime:"+lastExecuteTime); nRzD[3I
//System.out.print(" now:"+now+"\n"); qk<(iVUO
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); bx#GOK-
lastExecuteTime=now;
:?S1#d_
executeUpdate(); olB?"M=H
} zW+X5yK
else{ @FKm_q
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); )v
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} omevF>b;
} wuRQ
H]N
} 1Rg tZp%
//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 US[{
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类写好了,下面是在JSP中如下调用。 &mXJL3iN
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<% P/6$T2k_
CountBean cb=new CountBean(); [#hpWNez(>
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 1zqIB")s>
CountCache.add(cb); 6O"?wN%$
out.print(CountCache.list.size()+"<br>"); Vb yGr~t
CountControl c=new CountControl(); 33IJbg
c.run(); /
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out.print(CountCache.list.size()+"<br>"); W}{RJWr
%>