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: /A`zy
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CountBean.java APOU&Wd
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/* A0 w `o
* CountData.java (2a"W`
* M#gGD-
* Created on 2007年1月1日, 下午4:44 `E1_S
* "Z1&z-
* To change this template, choose Tools | Options and locate the template under >ehWjL`8
* the Source Creation and Management node. Right-click the template and choose }sN9QgE
* Open. You can then make changes to the template in the Source Editor. %0M^
*/ fgz'C?
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package com.tot.count; <38@b
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/** #j~FA3O
* ]> "/<"
* @author R5~vmT5W
*/ ;ZW}47:BS6
public class CountBean { >[3,qP]E
private String countType; 88LbO(q\d
int countId; 38.J:?Q
/** Creates a new instance of CountData */ lDM~Z3(/b
public CountBean() {} e, 3(i!47
public void setCountType(String countTypes){ UK9MWC5g9
this.countType=countTypes; It:QXLi;
} eX),B
public void setCountId(int countIds){ 2\8\D^
this.countId=countIds; %<o$
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} aGkVC*T
public String getCountType(){ %' g-%2C?
return countType; 8t
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} g"AfI
public int getCountId(){ <("w'd}
return countId; VX@G}3Ck
} 3e<^-e)+xL
} (dprY1noC
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CountCache.java tcdn"]#U
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/* wg~`Md
* CountCache.java |MR?8A^"
* QKkr~?sTO
* Created on 2007年1月1日, 下午5:01 9@a;1Wr/f
* PvBbtC-9b
* To change this template, choose Tools | Options and locate the template under #.t{g8W\C
* the Source Creation and Management node. Right-click the template and choose PKs%-Uk
* Open. You can then make changes to the template in the Source Editor. a~TZ9yg+HL
*/ DyTk<L
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package com.tot.count; .qPfi]
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import java.util.*; )GKgK;=~
/** 491I
* Bj[/tQ
* @author 6(^9D_"@
*/ aM}"DY-_
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public class CountCache { 25[/'7_"
public static LinkedList list=new LinkedList(); odn`%ok
/** Creates a new instance of CountCache */ )t=u(:u]
public CountCache() {} BT#g?=n#`
public static void add(CountBean cb){ L2$L.@
if(cb!=null){ /8HO7E+5
list.add(cb); sYI':UQe
} u\?u4
} yE9.]j
} )eMh,r
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CountControl.java X($SBUS6
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/* Z!eq /
* CountThread.java ;O11)u?/s|
* X5<.%@Z
* Created on 2007年1月1日, 下午4:57 .)zISa*Xy
* T$;XJx
* To change this template, choose Tools | Options and locate the template under I1Hw"G"&
* the Source Creation and Management node. Right-click the template and choose P?9nTG
* Open. You can then make changes to the template in the Source Editor. -VS9`7k
*/ |@ikx{W
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package com.tot.count; 9$7&URwSDI
import tot.db.DBUtils; &w+;N5}3
import java.sql.*; ;i<$7MR.e
/** ic%?uWN
* 9$Ig~W)
* @author ;~W8v.EW
*/ -O'{:s~
public class CountControl{ )!tCC-Cr
private static long lastExecuteTime=0;//上次更新时间 B\Xh3l]+j
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 CzYGq
/** Creates a new instance of CountThread */ ;mEwQ
public CountControl() {} T}C2e! _O
public synchronized void executeUpdate(){ 7#QLtU
Connection conn=null; OnZF6yfN=3
PreparedStatement ps=null; b,nn&B5@{
try{ OE_QInb<
conn = DBUtils.getConnection(); Lj}>Xy(7<
conn.setAutoCommit(false); ;W]D ~X&
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); &!ED# gs
for(int i=0;i<CountCache.list.size();i++){ #EJhAJ
CountBean cb=(CountBean)CountCache.list.getFirst(); 0y)}.'
CountCache.list.removeFirst(); x&'o ]Y
ps.setInt(1, cb.getCountId());
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ps.executeUpdate();⑴ kr%2 w
//ps.addBatch();⑵ Rv=DI&K%n
} &e5(Djz8t
//int [] counts = ps.executeBatch();⑶ Y RPm^kW
conn.commit(); #Mh{<gk%ax
}catch(Exception e){ !)N|J$FU
e.printStackTrace(); 8O>}k
} finally{ ]<1HM"D
try{ }.p<wCPy6
if(ps!=null) { %m9CdWb=w
ps.clearParameters(); 2K;#Evn'j
ps.close(); |'tW=
ps=null; >&OUGu|
} Cezh l
}catch(SQLException e){} %?bcT[|3
DBUtils.closeConnection(conn); Y$g}XN*)E
} \i!Son.<
} =VNSiK>F
public long getLast(){
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return lastExecuteTime; Ur^j$B}
} {Hl[C]25X
public void run(){ LOr|k8tL%
long now = System.currentTimeMillis(); FXV`9uq}Z
if ((now - lastExecuteTime) > executeSep) { P-CB;\
//System.out.print("lastExecuteTime:"+lastExecuteTime); MM?`voj~`p
//System.out.print(" now:"+now+"\n"); d t_e
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); r[s!F=^
lastExecuteTime=now; p~2UUmV
executeUpdate(); LvJGvj
} JQ@fuo %
else{ Gih[i\%Q
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); _tAQ=eBO
} &-%X:~|:X
} P}V=*g
} k;I &.H
//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 +E/y ~s
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类写好了,下面是在JSP中如下调用。 ,LZX@'5
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<% ;Wc4qJ.@
CountBean cb=new CountBean(); (vc|7DX M
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); iEIg:
CountCache.add(cb); ?7[alV ~
out.print(CountCache.list.size()+"<br>"); '9s5OTkN ;
CountControl c=new CountControl(); w5KPB5/zu
c.run(); 1f#mHt:(
out.print(CountCache.list.size()+"<br>"); .R5y:O
%>