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: g
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CountBean.java rF=\H3`p3
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/* I=&Kn@^
* CountData.java 9l}G{u9a
* D@yu2}F{IY
* Created on 2007年1月1日, 下午4:44 YbuS[l8
* F^X:5g~K
* To change this template, choose Tools | Options and locate the template under &U
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* the Source Creation and Management node. Right-click the template and choose I5w>*F
* Open. You can then make changes to the template in the Source Editor. <@+{EK'`q
*/
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package com.tot.count; (r"2XXR
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/** rY]QTS">o
* r$&WwH2^
* @author VZr AZV^c
*/ WS1#i\0
public class CountBean { .a
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private String countType; >jpkR
int countId; 3Hkb)Wu
/** Creates a new instance of CountData */ _rvO#h
public CountBean() {} kTm>`.kKJ=
public void setCountType(String countTypes){ }Bn`0;]
this.countType=countTypes; GqD_6cdh
} >+2gAO!
public void setCountId(int countIds){ OLyl.#J
this.countId=countIds; 3ULn ]jA
} F'^?s= QX
public String getCountType(){ YUQKy2
return countType; wU/BRz8I
} =\i{dj
public int getCountId(){ 4i(?5p>f
return countId; #\gx.2W7
} U t.#h="
} \Culf'iX
,2lH*=m;
CountCache.java aYcc2N%C
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/* i
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* CountCache.java Q a3+ 9
* D@o8Gerq~
* Created on 2007年1月1日, 下午5:01 '*n2<y
* )jed@?
* To change this template, choose Tools | Options and locate the template under 5DnX8t+d
* the Source Creation and Management node. Right-click the template and choose poVtg}n
* Open. You can then make changes to the template in the Source Editor. ljJR7<
*/ xc_-1u4a9
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package com.tot.count; &E`=pe/e
import java.util.*; Qk`LBvg1
/** 4pZ=CB+j
* l]z=0
* @author nsy eid*
*/ u]s}@(+.
public class CountCache { _?a.S8LxJZ
public static LinkedList list=new LinkedList(); _vr;cjMI
/** Creates a new instance of CountCache */ K)9+3(?
public CountCache() {} g0A,VX:2
public static void add(CountBean cb){ v}BXH4 &Y
if(cb!=null){ &KVXU0F^z
list.add(cb); L~e{Vv8UR
} 4?.L+wL
} W4n(6esO
} L3y`*&e>
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CountControl.java C^nTLw;K
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/* s.XLC43Rs
* CountThread.java |oV_7%mlu
* 9O\N
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* Created on 2007年1月1日, 下午4:57 )9z3T>QW
* 29r (Y
* To change this template, choose Tools | Options and locate the template under =JfSg'7
* the Source Creation and Management node. Right-click the template and choose Vl%jpjqP
* Open. You can then make changes to the template in the Source Editor. (v1~p3H
*/ oO][X
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package com.tot.count; `rZS\A
import tot.db.DBUtils; 1$1P9x@H
import java.sql.*; :V^|}C#
/** B),Z*lpC
* nbdjk1E`~
* @author 6$LQO),,
*/ Z$:iq
public class CountControl{ Wd]MwDcO
private static long lastExecuteTime=0;//上次更新时间 *1CZRfWI
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 q1vsvL9Q
/** Creates a new instance of CountThread */ >!%F$$
public CountControl() {} 2~RG\JWTA
public synchronized void executeUpdate(){ .Fm@OQr
Connection conn=null; !TeI Jm/l
PreparedStatement ps=null; R&9Q#n-
try{ |}naI_Qudv
conn = DBUtils.getConnection(); !\/J|~XZ
conn.setAutoCommit(false); G2!J`}
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); @szr '&\%A
for(int i=0;i<CountCache.list.size();i++){ J0,;F9<C#X
CountBean cb=(CountBean)CountCache.list.getFirst(); gMUCVKGf
CountCache.list.removeFirst(); E% d3}@
ps.setInt(1, cb.getCountId()); pW1(1M)[%Z
ps.executeUpdate();⑴ L1YiXJ,T,
//ps.addBatch();⑵ I"bz6t\~|
} ^{l$>e]
//int [] counts = ps.executeBatch();⑶ 3jDAj!_ea
conn.commit(); y]b&3&
}catch(Exception e){ 6uKS!\EY|
e.printStackTrace(); k07pI<a?
} finally{ <_~e/+_.
try{ F7 IZ;4cp
if(ps!=null) { Q+a"Z^Z|
ps.clearParameters(); [ %6(1$Ih
ps.close(); D2MWrX
ps=null; }-H)jN^
} L{Kl!
}catch(SQLException e){} x f<wM]&
DBUtils.closeConnection(conn); sX,S]:X
} %2^wyVkq:
} ?OF9{$m3?
public long getLast(){ V3c7F4\
return lastExecuteTime; OS sYmF
} vfloha p
public void run(){ h"t\x}8qq
long now = System.currentTimeMillis(); vk.P| Y-;
if ((now - lastExecuteTime) > executeSep) { NNw0
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//System.out.print("lastExecuteTime:"+lastExecuteTime); 8=,-r`oNy
//System.out.print(" now:"+now+"\n"); (qdvvu#E
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); LGT?/gup
lastExecuteTime=now; 'ocPG.PaU
executeUpdate(); = ow=3Ku
} vXT>Dc2\!
else{ xA SH-9
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); &AP`k
} *I9O+/,
} dq^vK
} +a0` ,Jc
//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 *=zv:!
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类写好了,下面是在JSP中如下调用。
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