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: U;gy4rj
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CountBean.java 2#'"<n,G
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/* Xj:\B] v]
* CountData.java q@Zeu\T,*#
* 5o0H7k]
* Created on 2007年1月1日, 下午4:44 Yof]
* 4hn'b[
* To change this template, choose Tools | Options and locate the template under 'ztY>KV j
* the Source Creation and Management node. Right-click the template and choose g=Nde2d?
* Open. You can then make changes to the template in the Source Editor. G@<[fO|Iam
*/ "2T* w~V&y
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package com.tot.count; W@~a#~1O
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/** qf%p#+:B3
* 0X%#9s~
* @author vnX~OVz2
*/ <_4'So>
public class CountBean { }w)wW1&
private String countType; ]YB,K)WQ
int countId; @rr\Jf""z
/** Creates a new instance of CountData */ i\RB KF
public CountBean() {} 2JHV*/Q
public void setCountType(String countTypes){ Qr~yHFc1y
this.countType=countTypes; i\{fM}~W$
} rP}0B/
public void setCountId(int countIds){ KoFWI_(b
this.countId=countIds; -V||1@
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} .?r}3Ch
public String getCountType(){ @%6"xnb`
return countType; 1c$ce+n~
} >W'"xK|:
public int getCountId(){ 0|(6q=QK
return countId; Vv>hr+e
} dewN\
} wd
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CountCache.java gy/bA
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/* WhDNt+uk)
* CountCache.java 44UN*_qG
* l D]?9K29
* Created on 2007年1月1日, 下午5:01 9NqZ&S
* b yJ[1UK
* To change this template, choose Tools | Options and locate the template under * YTv"
* the Source Creation and Management node. Right-click the template and choose DXfQy6k'
* Open. You can then make changes to the template in the Source Editor. ,f[Oy:fr
*/ 0y/P
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package com.tot.count; ^~m}(6
import java.util.*; +kOXa^K
/** Q_|Lv&
* IHe?/oUL"b
* @author v79\(BX
*/ ^L's45&_
public class CountCache { nsi&r
public static LinkedList list=new LinkedList(); Qh4Z{c@
/** Creates a new instance of CountCache */ f`p"uLNo<
public CountCache() {} P? LpI`f
public static void add(CountBean cb){ c nV2}U/\
if(cb!=null){ :"Kr-Hm`
list.add(cb); $`Aps7A
} k)S'@>n{u
} O)}5`0@L
} @86I|cY
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CountControl.java THnZbh4#)
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/* 7 gT^ZL
* CountThread.java &y:SK)
* );ZxKGjc4
* Created on 2007年1月1日, 下午4:57 qbQH1<yS<
* rFYw6&;vOi
* To change this template, choose Tools | Options and locate the template under Blv@u ?
* the Source Creation and Management node. Right-click the template and choose |(rTz!!-
* Open. You can then make changes to the template in the Source Editor. hxsW9
*/ CYN|
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package com.tot.count; xtRHb''FX
import tot.db.DBUtils; ,c[f/sT\
import java.sql.*; bJ9K!6s??`
/** F]^ZdJ2
* C2W&*W*
* @author Y+_t50S
*/ PkxhR;4
public class CountControl{ vrvOPLiQ
private static long lastExecuteTime=0;//上次更新时间 M\dZxhQ-l
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 WhN~R[LE_
/** Creates a new instance of CountThread */ Fs;_z9ej-u
public CountControl() {} hZLwg7X!
public synchronized void executeUpdate(){ p*"H&xA@
Connection conn=null; `'M}.q,k~
PreparedStatement ps=null; O{nM
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try{ %v 1NDhaXz
conn = DBUtils.getConnection(); *9xv0hRQ%?
conn.setAutoCommit(false); ayoqitXD?
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); m8<l2O=m
for(int i=0;i<CountCache.list.size();i++){ YCEdt>5PA
CountBean cb=(CountBean)CountCache.list.getFirst(); G,JNUok
CountCache.list.removeFirst(); U<mFwJ C]
ps.setInt(1, cb.getCountId()); xdd;!HK,
ps.executeUpdate();⑴ ;]xJC
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//ps.addBatch();⑵ w-9fskd6e
} uGH>|V9'c
//int [] counts = ps.executeBatch();⑶ eNw9"X}g
conn.commit(); 0*}%v:uN9
}catch(Exception e){ \1b! I)T9
e.printStackTrace(); bClMM
} finally{ ZF6?N?t}h8
try{ Ju.B!)uS#
if(ps!=null) { T`.RP&2/d
ps.clearParameters(); yCT:U&8%F
ps.close(); 2[R{IV8e
ps=null; ;OynkZs)
} V[T`I a\
}catch(SQLException e){} +Pm
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DBUtils.closeConnection(conn); ?A7_&=J%
} }tRY,f
} }+Ne)B E
public long getLast(){ m?Qr)F_M
return lastExecuteTime; vkQkU,q
} yC]X&1,:z
public void run(){ o:irwfArv
long now = System.currentTimeMillis(); 4PzCm k
if ((now - lastExecuteTime) > executeSep) { i-`n5,
//System.out.print("lastExecuteTime:"+lastExecuteTime); }^np
//System.out.print(" now:"+now+"\n"); =Vm"2g,aA
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); J` J^C
lastExecuteTime=now; *.]M1
executeUpdate(); D-<9kBZs
} g-Y2U}&
else{ u79,+H@ep
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); {q-<1|xj/J
} 6*n<emP
} d!i#@XZ^
} uYv"5U]MFv
//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 J<4egk4
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类写好了,下面是在JSP中如下调用。 udV.$N
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<% Mr3;B+S
CountBean cb=new CountBean(); X <<hb
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 4G4[IAu_
CountCache.add(cb); mu?6Phj
out.print(CountCache.list.size()+"<br>"); }yfSF|\
CountControl c=new CountControl(); dMnJ)R
c.run(); g5
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out.print(CountCache.list.size()+"<br>"); cJnAwIs_e`
%>