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: \c\=S
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CountBean.java 8)tyn'~i
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/* ""a8eB6
* CountData.java DVS7N_cx2o
* @t^2/H
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* Created on 2007年1月1日, 下午4:44 [<`+9R
* ?yU#'`q
* To change this template, choose Tools | Options and locate the template under 'oEmbk8Hg
* the Source Creation and Management node. Right-click the template and choose 8`~]9ej
* Open. You can then make changes to the template in the Source Editor. x('yBf
*/ qXF"1f_+
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package com.tot.count; Bx qCV%9o
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/** +vnaEy
* Zk[#BUA
* @author fI|1@e1
*/ `WT7w']NT
public class CountBean { [n"<(~
private String countType; ?`XKaD!
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int countId; 'YeJGzsJp
/** Creates a new instance of CountData */ PA/6l"-`3
public CountBean() {} d]^i1
public void setCountType(String countTypes){ # 9t/j`{
this.countType=countTypes; EGt)tI&
} 8HOmWQS
public void setCountId(int countIds){ ]5\vYk
this.countId=countIds; gc=e)j@
} >xjy
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public String getCountType(){ 6uyf
return countType; 6>Cubb>
} U&XoT-p$L
public int getCountId(){ 4HJrR^
return countId; 'FhnSNT(4=
} qrkT7f
} Xy{+=UY
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CountCache.java }NXESZYoi
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/* y
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* CountCache.java Fk(5y)
* Z:_y,( 1Q
* Created on 2007年1月1日, 下午5:01 S(6ZX>wv:
* d#\n)eGr
* To change this template, choose Tools | Options and locate the template under "Tv7*3>
* the Source Creation and Management node. Right-click the template and choose `{Jb{L@f
* Open. You can then make changes to the template in the Source Editor. FScQS.qF
*/ )YFs
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package com.tot.count; y6/X!+3+
import java.util.*; U6Ak"
/** m"R(_E5
* v,&2!Zv
* @author ^U}0D^jDeE
*/ Q6K)EwN
public class CountCache {
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public static LinkedList list=new LinkedList(); R=PzR;8
/** Creates a new instance of CountCache */ V1.F`3h~
public CountCache() {} ~|rkt`8p
public static void add(CountBean cb){ D;]%
if(cb!=null){ 0, /x#
list.add(cb); :!$z1u8R
} s/M~RB!w
} Kcl$|T
} 37xxVbik
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CountControl.java {%{GZ
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/* sFK<:ka
* CountThread.java _GqE'VX
* SK52.xXJ
* Created on 2007年1月1日, 下午4:57 "N]o5d
* s? k[_|)!
* To change this template, choose Tools | Options and locate the template under keskD
* the Source Creation and Management node. Right-click the template and choose Wi^rnr'Ss
* Open. You can then make changes to the template in the Source Editor. pm\X*t}L
*/ *a!!(cZZ
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package com.tot.count; P-[K*/bPw
import tot.db.DBUtils; j_@3a)[NY
import java.sql.*; _eV n#!|
/** .5;LL,S-
* !T#y r)
* @author m7vxzC*
*/ CDnz
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public class CountControl{ |+-i'N9
private static long lastExecuteTime=0;//上次更新时间 acQNpT
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ~+C?][T
/** Creates a new instance of CountThread */ k &iDJt
public CountControl() {} W"(`n4hi3
public synchronized void executeUpdate(){ mwH!:f
Connection conn=null; "H<#91^|
PreparedStatement ps=null; 2F@)nh
try{ '-33iG
conn = DBUtils.getConnection(); :xS&Y\ry
conn.setAutoCommit(false); m,C,<I|'d
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); uhB!k-ir
for(int i=0;i<CountCache.list.size();i++){ FK# E7
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CountBean cb=(CountBean)CountCache.list.getFirst(); x ;,xd
CountCache.list.removeFirst(); %aBJ+V F
ps.setInt(1, cb.getCountId()); +\GZ(!~
ps.executeUpdate();⑴ ,, %:vK+V
//ps.addBatch();⑵ l/zC##1+.
} ,Bw)n,
//int [] counts = ps.executeBatch();⑶ !]+Z%ed`%
conn.commit(); Y{vwOs
}catch(Exception e){ 6h6?BQSE
e.printStackTrace(); NLZZMr
} finally{ B36puz 0{
try{ W^.-C
if(ps!=null) { X2dc\v.x
ps.clearParameters(); Q &7)vs
ps.close(); !{tiTA
ps=null; ttFY
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} kEhm'
}catch(SQLException e){} $>"e\L4Kp
DBUtils.closeConnection(conn); }?]yxa ~
} h^+C)6(58n
} :q64K?X
public long getLast(){ U5CPkH1
return lastExecuteTime; ^M"z1B]
} XL
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public void run(){ M&/aJRBS
long now = System.currentTimeMillis(); 2k}-25xxL
if ((now - lastExecuteTime) > executeSep) { TT2cOw
//System.out.print("lastExecuteTime:"+lastExecuteTime); 4 %)N(%u
//System.out.print(" now:"+now+"\n"); .^~l_LkA
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); -9>LvLU
lastExecuteTime=now; 0GX10*t.
executeUpdate(); Np<s[dQ
} sCtw30BL
else{ /8>0;bX+
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); -*%!q$:
} Fu4EEi
} Z@,PZ
} hzQ+9-qA
//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 G_M:0YI@
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类写好了,下面是在JSP中如下调用。 @>G&7r:U
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<% 2:iYYRrg
CountBean cb=new CountBean(); 0SMQDs5j
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); f(6UL31
CountCache.add(cb); Xqg.kX
out.print(CountCache.list.size()+"<br>"); w}j6.r
CountControl c=new CountControl(); | 7 m5P@X
c.run(); FE+7X=y
out.print(CountCache.list.size()+"<br>"); s~LZOPN
%>