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: T?:Rdo!:u
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CountBean.java (*Z)(O*z
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/* m`v2: S}
* CountData.java #Vl 0.l3
* ]Uw<$!$-]s
* Created on 2007年1月1日, 下午4:44 V `b2TS
* M3J#'%$
* To change this template, choose Tools | Options and locate the template under NV)!7~r}:
* the Source Creation and Management node. Right-click the template and choose :?k>HQe
* Open. You can then make changes to the template in the Source Editor. SHvq.lYJ
*/ Wl;.%.]>
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package com.tot.count; u6M.'
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/** c]$i\i#
* B268e
* @author FYOD
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*/ ^@I
public class CountBean { pM^9c7@!:
private String countType; G'rxXJq
int countId; 3;)>Fs;
/** Creates a new instance of CountData */ IM:=@a{
public CountBean() {} tkVbo.[8K
public void setCountType(String countTypes){ oeKHqP wg
this.countType=countTypes; K\>tA)IPSV
} hhSy0
public void setCountId(int countIds){ XUM!Qv
this.countId=countIds; VcAue!MN
} *YW/_
public String getCountType(){ &K[_J
return countType; 3t`P@nL0;
} J cg,#@
public int getCountId(){ @En^wN
return countId; g3Ec"_>P
} Mx6@$tQ%
} M^MdRu
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CountCache.java -mC0+}h
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/* kUq=5Y `D
* CountCache.java W!%]_I!&K
* ` BDLW%aL
* Created on 2007年1月1日, 下午5:01 0n@rLF
* ^:K3vC[h;c
* To change this template, choose Tools | Options and locate the template under un shH <
* the Source Creation and Management node. Right-click the template and choose FjK3
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* Open. You can then make changes to the template in the Source Editor. ?;KKw*
*/ lwHzj&/ ~
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package com.tot.count; UUSq$~Ct
import java.util.*; _ 6O\W%it
/** bnm
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* D Gr>
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* @author BsBK@+ZyI
*/ {xwm^p(f
public class CountCache { 2uG0/7
public static LinkedList list=new LinkedList(); l-K9LTd
/** Creates a new instance of CountCache */ cYFiJJLG]
public CountCache() {} j H19k}D
public static void add(CountBean cb){ Acnl^x7Y1
if(cb!=null){ e.]K L('
list.add(cb); aF)1Nm[
} GRGzP&}@
} ^sa#8^,K
} jL(qf~c_
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CountControl.java c05TsMF&O
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/* ;ToKJ6hN|*
* CountThread.java HuB<k3#sPy
* S7=Bd[4
* Created on 2007年1月1日, 下午4:57 q+P|l5_
t
* aT_&x@x
* To change this template, choose Tools | Options and locate the template under 8S>&WR%jH]
* the Source Creation and Management node. Right-click the template and choose ([
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* Open. You can then make changes to the template in the Source Editor. `n$I]_}/%
*/ :/y1yM
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package com.tot.count; `^bgUmJ~
import tot.db.DBUtils; D-8O+.@
import java.sql.*; %T X@I$Ba
/** g$HwxA9Gp/
* .}'qUPNR
* @author &F\?
*/ Em?d*z
public class CountControl{ JXCCTUO
private static long lastExecuteTime=0;//上次更新时间 }tsYJlh5
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 "[vu6 `m?
/** Creates a new instance of CountThread */ y|CP;:f;
public CountControl() {} EPS={w$'s
public synchronized void executeUpdate(){ W.z;B<
Connection conn=null; lCAIK
PreparedStatement ps=null; yMyE s 8
try{ 7G.#O}).b
conn = DBUtils.getConnection(); *&?c(JU;<
conn.setAutoCommit(false); HU%o6c w
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); K/A*<<r
~
for(int i=0;i<CountCache.list.size();i++){ 8d?g]DEN)6
CountBean cb=(CountBean)CountCache.list.getFirst(); "5;;)\o~
CountCache.list.removeFirst(); @.G[s)x
ps.setInt(1, cb.getCountId()); ~7Ts_:E-
ps.executeUpdate();⑴ f>aEkh6u9
//ps.addBatch();⑵ jZh';M8"
} P/xKnm~
//int [] counts = ps.executeBatch();⑶ R16'?,
conn.commit(); XpmS{nb
}catch(Exception e){ bA=
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e.printStackTrace(); (:._"jp]
} finally{
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try{ ktj]:rCkF
if(ps!=null) { CK:y?
ps.clearParameters(); Yiry["[]Q
ps.close(); T_sTC)&a
ps=null; :/:.Kb
} 8aO~/i:(.
}catch(SQLException e){} s_x:T<]
DBUtils.closeConnection(conn); @7n/Q(
} @kk4]:,w
} ojQI7 Uhw
public long getLast(){ H,+I2tEs
return lastExecuteTime; H2Z1TIh
} ]?3un!o3o
public void run(){ zXv3:uRp.
long now = System.currentTimeMillis(); e_s&L,ze
if ((now - lastExecuteTime) > executeSep) { ?47@o1
//System.out.print("lastExecuteTime:"+lastExecuteTime); Vnx,5E&
//System.out.print(" now:"+now+"\n"); _/Gczy4)#
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); `kbSu}
lastExecuteTime=now; uwa~-xX6
executeUpdate(); vJ\pR~?
} N` aF{3[
else{ a;QMAd!
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); rA2g&
} 6b%WHLUeT
} ^xh}I5
} .mDM[e@'
//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 /I)yU>o
Q2zjZC*'%
类写好了,下面是在JSP中如下调用。 <Ard7UT
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<% [[>wB[w
CountBean cb=new CountBean(); I4i2+
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *g y{]
CountCache.add(cb); $ "E).j
out.print(CountCache.list.size()+"<br>"); 8wVY0oRnU
CountControl c=new CountControl(); u}!@ ,/)
c.run(); 'd+NVj{C
out.print(CountCache.list.size()+"<br>"); MS0Fl|YA
%>