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: -z&9DWH
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CountBean.java rrbZ+*U
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/* ]m RF[b$
* CountData.java Fu#Y7)r
* &8zk3
* Created on 2007年1月1日, 下午4:44 q~mcjbLz
* l(.7t'
* To change this template, choose Tools | Options and locate the template under :S#eg1y.w]
* the Source Creation and Management node. Right-click the template and choose vW9^hbdx
* Open. You can then make changes to the template in the Source Editor. {~ ":;
*/ X3<SP
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package com.tot.count; Cx$9#3\
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/** h=:*7>}
* ;U8dm"
* @author Lax9
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*/ 7eTA`@v5A
public class CountBean { ozT._C
private String countType; T..-)kL+p
int countId; W5TqC
/** Creates a new instance of CountData */ >Zi|$@7t-
public CountBean() {} twAw01".
public void setCountType(String countTypes){ p0"BO4({{
this.countType=countTypes; Qh/lT$g
} TeOFAIU
public void setCountId(int countIds){ ?exALv'B
this.countId=countIds; <<i=+ed8eP
} !d/`[9jY
public String getCountType(){ qdKh6{
return countType; <?{ SU
} ))c*_n
public int getCountId(){ ^.nwc#
return countId; >:="?'N5l!
} 7$;c6_se
} 4&#vU(-H
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CountCache.java ^Z#<tN;
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/* :k Rv
* CountCache.java Z`e$~n(Bh
* f:)]FHPB1
* Created on 2007年1月1日, 下午5:01 ZKVp[A
* 1t!&xvhG
* To change this template, choose Tools | Options and locate the template under = .fc"R|<K
* the Source Creation and Management node. Right-click the template and choose c }g$1of87
* Open. You can then make changes to the template in the Source Editor. A{xSbbDk
*/ g`y/_
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package com.tot.count; (\5<GCW-
import java.util.*; MZgmv
/** Nj! R9N
* "i;*\+x
* @author }s8*QfK>
*/ h5h-}qBA
public class CountCache { 1"87EP
public static LinkedList list=new LinkedList(); _Eet2;9
/** Creates a new instance of CountCache */ C`=`Ce~|d
public CountCache() {} 3/]f4D{MMY
public static void add(CountBean cb){ -K{\S2
if(cb!=null){ #$9U=^Z[
list.add(cb); 2nOe^X!*
} C={sE*&dYX
} q{N lF$X
} B{=,VwaP_
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CountControl.java 6EW"8RG`
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/* ulJ+:zwq$
* CountThread.java /
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* ZVCv(J
* Created on 2007年1月1日, 下午4:57 JC1BUheeb
* Y+S~b
* To change this template, choose Tools | Options and locate the template under ^ ^U)WB
* the Source Creation and Management node. Right-click the template and choose D(W7O>5vQ2
* Open. You can then make changes to the template in the Source Editor. t/4/G']W
*/ !YuON6{)
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package com.tot.count; *;~{_Disz
import tot.db.DBUtils; k;9#4^4(
import java.sql.*; O;.d4pO(tC
/** I+-Rs2wb
* 4.$hHFqS^5
* @author |G5=>W
*/ iyHp$~,q?t
public class CountControl{ Av\0GqF
private static long lastExecuteTime=0;//上次更新时间 HvL9;^!
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Q'vIeG"o
/** Creates a new instance of CountThread */ eFeCS{LV+
public CountControl() {} 'JXN*YO
public synchronized void executeUpdate(){ ?j
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Connection conn=null; OmQuAG
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PreparedStatement ps=null; oD|+X/FK
try{ B@:XC&R^
conn = DBUtils.getConnection(); `jl. f
conn.setAutoCommit(false); y[Fw>g1`q
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); $ET/0v"V
for(int i=0;i<CountCache.list.size();i++){ <{P^W;N7
CountBean cb=(CountBean)CountCache.list.getFirst(); Wl^/=I4p#
CountCache.list.removeFirst(); uvAy#,
ps.setInt(1, cb.getCountId()); QyBK*uNdV
ps.executeUpdate();⑴ D(2kb
//ps.addBatch();⑵ =h1 QN
} WHh2fN'A5
//int [] counts = ps.executeBatch();⑶ e=NQY8?
conn.commit(); TbSt{TX
}catch(Exception e){ o8yEUnqN
e.printStackTrace(); LP-KD
} finally{ (*@~HF,t=
try{ HEW9YC"
if(ps!=null) {
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ps.clearParameters(); zke~!"iq
ps.close(); +P<w<GfQ
ps=null; JhhT7\h(
} +BTNm66Z
}catch(SQLException e){} )l81R
DBUtils.closeConnection(conn); pR^Y|NG!
} Xj&~N;Ysb
} ;#Bh_f
public long getLast(){ 4w/t$lR
return lastExecuteTime; LxYM"_1A;
} 2&G1Q'!
public void run(){ f1,$<Y|qU
long now = System.currentTimeMillis(); _yXeX
if ((now - lastExecuteTime) > executeSep) { 71,0v`Z<
//System.out.print("lastExecuteTime:"+lastExecuteTime); 8aIq#v
//System.out.print(" now:"+now+"\n"); jL[Is2<@
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;Bc<u[G
lastExecuteTime=now; d1LTyzLr
executeUpdate(); t+Q|l&|0
} r
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else{ QK/+*hr;
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); #+5mpDh
} APOU&Wd
} *p<5(-J3
} g{f>jd
//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 [OToz~=)
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类写好了,下面是在JSP中如下调用。 qS`|=5f
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<% 26klW:2*
CountBean cb=new CountBean(); "vHAp55B{
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); P(gID
CountCache.add(cb); 5In8VE
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out.print(CountCache.list.size()+"<br>"); <38@b
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CountControl c=new CountControl(); 7ump:|
c.run(); D_;n4<|.
out.print(CountCache.list.size()+"<br>"); ]> "/<"
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