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: i;29*"
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CountBean.java BP\6N%HC%&
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/* !*?9n^PaF
* CountData.java @tJic|)x
* O,NVhU7,
* Created on 2007年1月1日, 下午4:44 >Ml5QO$*.q
* *{\))Zmhd
* To change this template, choose Tools | Options and locate the template under (<e<Q~(
* the Source Creation and Management node. Right-click the template and choose B`jq"[w]-
* Open. You can then make changes to the template in the Source Editor. 1i)3!fH0:
*/ cF?0=un
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package com.tot.count; B$hog_=s
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/** M9Nr/jE
* \F""G,AWq{
* @author U;!J(Us
*/ 8yH)9#>
public class CountBean { 3iL\<^d*ht
private String countType; Sn'
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int countId; L1y71+iqU
/** Creates a new instance of CountData */ cRWB`&
public CountBean() {} lWT`y
public void setCountType(String countTypes){ <vD(,||
this.countType=countTypes; ,@Kn@%?$
} Hk(=_[S
public void setCountId(int countIds){ kJNwA8 7
this.countId=countIds; 'G>9 iw
} \wK4bvUrX
public String getCountType(){ qOnGP{
return countType; l(@c
} 3=*ur( Qy
public int getCountId(){ N0JdU4'
return countId; eg1F[~YL/
} ,(f W0d#
}
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CountCache.java <$otBC/%
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/* &
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* CountCache.java 4%I[.dBnM
* SQ/HZ
* Created on 2007年1月1日, 下午5:01 }6=)w@v
* A5%$<
* To change this template, choose Tools | Options and locate the template under ,H^!G\
* the Source Creation and Management node. Right-click the template and choose D_)/.m
* Open. You can then make changes to the template in the Source Editor. 18Ju]U
*/ g#cet{>
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package com.tot.count; {Qn{w%!|
import java.util.*; LhM$!o?W
/** LIQ].VxIs
* s{j A!T}
* @author 7q5*grm
*/ Z&P\}mm
public class CountCache { mVh;=>8K
public static LinkedList list=new LinkedList(); y~VI,82*
/** Creates a new instance of CountCache */ $em'H,*b3
public CountCache() {} ='m%Iq7X
public static void add(CountBean cb){ z0 #2?o
if(cb!=null){ 9\/oL{
list.add(cb); \k{[HfVvn
} "Wr[DqFd
} vUOl@UQ5
} *c&|2EsZ
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CountControl.java 2A:h&t/|C
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/* ?( z"Ub]
* CountThread.java VxARJ*4=Y
* a6 0rJ#GD
* Created on 2007年1月1日, 下午4:57 F[`dX
* x{tlC}t
* To change this template, choose Tools | Options and locate the template under vLyazVj..
* the Source Creation and Management node. Right-click the template and choose B&0W P5OF
* Open. You can then make changes to the template in the Source Editor. |r36iUHZS
*/ Id>4fF:o
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package com.tot.count; m8e()8lZ3
import tot.db.DBUtils; Kfr1k
import java.sql.*; P".IW.^kk~
/** 4v3gpLH
* x;\/Xj;
* @author F"O\uo:3
*/ gq/Za/!6
public class CountControl{ b78~{ht`
private static long lastExecuteTime=0;//上次更新时间 (/,l0
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 0\X<vrW
/** Creates a new instance of CountThread */ i1-%#YYF(
public CountControl() {} /]MelW
public synchronized void executeUpdate(){ )|^8`f
Connection conn=null; jlFlhj:/I
PreparedStatement ps=null; di0@E<@1:
try{ L$.3,./
conn = DBUtils.getConnection(); 1 <+aF,
conn.setAutoCommit(false); +}a(jO
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Jww#zEK
for(int i=0;i<CountCache.list.size();i++){ "J=Cy@SSa
CountBean cb=(CountBean)CountCache.list.getFirst(); isQOt *
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CountCache.list.removeFirst(); Hq 3V+$
ps.setInt(1, cb.getCountId()); OE9,D:tv
ps.executeUpdate();⑴ :zPK
//ps.addBatch();⑵ n-yUt72
} GZNN2
'
//int [] counts = ps.executeBatch();⑶ 2A[hMbL
conn.commit(); 6$'*MpYF4
}catch(Exception e){ 5)eM0,:
e.printStackTrace(); El;"7Qn
} finally{ Jou*e%
try{ tqCkqmyC
if(ps!=null) { &tvp)B?cWk
ps.clearParameters(); l&'q+F
ps.close(); EwA*
ps=null; 4gsQ:3
} 7bihP@I!
}catch(SQLException e){} ZDgT"53
DBUtils.closeConnection(conn); ^-[
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} p\lR1
} UU MB"3e
public long getLast(){ E5M/XW\E6
return lastExecuteTime; !]82$
} C&MqH.K
public void run(){ dS4z Oz"
long now = System.currentTimeMillis(); )H{1Xjh-
if ((now - lastExecuteTime) > executeSep) { z[v4(pO6
//System.out.print("lastExecuteTime:"+lastExecuteTime); ^MF 2Q+
//System.out.print(" now:"+now+"\n"); KvPCb%!ZP
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); zIjfxK
lastExecuteTime=now; tm^joK[{|J
executeUpdate(); ZL\^J8PRK
} , 6X;YY
else{ 9&AO
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); )`f-qTe
} 1BU97!
} >19s:+
} \\#D!q*
//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 UGy3B)
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类写好了,下面是在JSP中如下调用。 ,.>9$( s
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<% WcNQF!f
CountBean cb=new CountBean(); A#T"4'#?<
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); PENB5+1OK
CountCache.add(cb); !V3+(o1
out.print(CountCache.list.size()+"<br>"); C1=&Vm>g+
CountControl c=new CountControl(); <TtPwUX
c.run(); abR<( H12
out.print(CountCache.list.size()+"<br>"); qpYgTn8l7
%>