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: @MoKWfc
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CountBean.java !d'GE`w T
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/* f<GhkDPm>?
* CountData.java Yh7rU?Gj
* |O3q@
* Created on 2007年1月1日, 下午4:44 8aZ=?_gvT
* cv8L-Z>x.=
* To change this template, choose Tools | Options and locate the template under 3v(* 5
* the Source Creation and Management node. Right-click the template and choose Pi=+/}
* Open. You can then make changes to the template in the Source Editor. ;$HftG>B
*/ .28<tEf
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package com.tot.count; -<6\1J
} j<)L,
/** __uA}fZp
*
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* @author /pm]BC
*/ CMe
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public class CountBean { rr/B=O7
private String countType; XWnVgY s
int countId; 5CuuG<0
/** Creates a new instance of CountData */ X3(tuqmi
public CountBean() {} a,Sw4yJ!Q
public void setCountType(String countTypes){ =NpYFKmMhV
this.countType=countTypes; FW.7'7G@n
} z Eq GD2"
public void setCountId(int countIds){ 57aXQ8u{
this.countId=countIds; (XVw"m/ye
} M\vwI"
public String getCountType(){ q$p%ZefZ
return countType; ) g0%{dfJ
} Y$o<6[7
public int getCountId(){ U] ~$g}!)
return countId; (DJ"WG
} RPwbTAl}
} C,wL0Yj[
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CountCache.java LI'6R=
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/* ]E7F/O/.
* CountCache.java 2uzW+D6J
* j~"Q3P;V
* Created on 2007年1月1日, 下午5:01 H-WJp<_
* :8I9\eet3
* To change this template, choose Tools | Options and locate the template under 9FoHD
* the Source Creation and Management node. Right-click the template and choose vGvf<ra;H
* Open. You can then make changes to the template in the Source Editor. dW_KU}
*/ j
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package com.tot.count; #TeG-sFJg@
import java.util.*; ]"r&]qx7
/** B#exHf8
* w2;eh]k
* @author ]5mn ew
*/ }\hVy(\c
public class CountCache { x`U^OLV
public static LinkedList list=new LinkedList(); 'g6\CZw(#
/** Creates a new instance of CountCache */ tG:25 T0
public CountCache() {} .>q8W
public static void add(CountBean cb){ =FlDb
5t{
if(cb!=null){ Z|%_&M
list.add(cb); YA''2Ii
} Az9?Ra;U
} j1^I+j)
} 1!ii;s^e
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CountControl.java >i_2OV
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/* EtJHR
* CountThread.java Ua<5U5
* G"klu
* Created on 2007年1月1日, 下午4:57 grS:j+_M2m
* ;i8g41qjF
* To change this template, choose Tools | Options and locate the template under . kQkC:~9
* the Source Creation and Management node. Right-click the template and choose M*y)6H k~
* Open. You can then make changes to the template in the Source Editor. <W|3\p6
*/ H6kR)~zhf
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package com.tot.count; ;}7Rjl#
import tot.db.DBUtils; E08klC0
import java.sql.*; "K ~
/** k;2GEa]w
* |"?M 1*g
* @author FI[A[*fi
*/ J
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public class CountControl{ *,3SGcYdJj
private static long lastExecuteTime=0;//上次更新时间 .nB0 h
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 83E7k]7]
/** Creates a new instance of CountThread */ uya.sF0]9B
public CountControl() {} u0 P|0\
public synchronized void executeUpdate(){ bmJ5MF]_fG
Connection conn=null; _|iSF2f,X
PreparedStatement ps=null; zxJ]"N
try{ wi;Br[d
conn = DBUtils.getConnection(); 3Iua*#<m,
conn.setAutoCommit(false); wE[]6\_x1
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ]"J~:{, d
for(int i=0;i<CountCache.list.size();i++){ _+p4Wvu~0
CountBean cb=(CountBean)CountCache.list.getFirst(); MV<^!W
CountCache.list.removeFirst(); wL;lQ&
ps.setInt(1, cb.getCountId()); g@rb
ps.executeUpdate();⑴ VkvB<3
//ps.addBatch();⑵ E4xj?m^(y=
} +lm{Olm'^
//int [] counts = ps.executeBatch();⑶ 4F)-"ck
conn.commit(); RwKdxK+;
}catch(Exception e){ Mc=$/ o
e.printStackTrace(); OJ,`
} finally{ 3)8QS
try{ 34z"Pm
if(ps!=null) { b$4"i XSQ
ps.clearParameters(); XnDUa3
ps.close(); 11TL~xFh
ps=null; V\{clJ\U
} ~s%
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}catch(SQLException e){} T~--92[
DBUtils.closeConnection(conn); 9`wZz~hL"
} %Qc La//
} S)lkz'tdk
public long getLast(){ #EO9UW5
return lastExecuteTime; t=|evOz]
} @AGn{q
public void run(){ X59:C3c
long now = System.currentTimeMillis(); l%[EXZ
if ((now - lastExecuteTime) > executeSep) { ?6yjy<D)$e
//System.out.print("lastExecuteTime:"+lastExecuteTime); z,Medw6[
//System.out.print(" now:"+now+"\n"); Xp >7iX!:
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); u&`XB|~
lastExecuteTime=now; >CrA;\l
executeUpdate(); d_CKP"TA
} 0>C T=(A
else{ n.T&}ZPz\v
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); o4j[p3$
} cimp/n"
} %{ABaeb]
} *194{ ep
//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 jNTjSX
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类写好了,下面是在JSP中如下调用。 iEd\6EZ
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<% Kh,V.+7k
CountBean cb=new CountBean(); J]v%q,"
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); IzsphBI
CountCache.add(cb); }x@2]juJ
out.print(CountCache.list.size()+"<br>"); u6T+Cg
CountControl c=new CountControl(); Q?e*4ba
c.run(); QOjqQfmM;
out.print(CountCache.list.size()+"<br>"); qLw{?sH}J/
%>