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: 8KwCwv
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CountBean.java l@rwf$-
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/* zX [r
* CountData.java fTV|?:C{
* 92]ZiL?k
* Created on 2007年1月1日, 下午4:44 _T|H69 J
* E\~ KVn
* To change this template, choose Tools | Options and locate the template under ITIj=!F*
* the Source Creation and Management node. Right-click the template and choose |W*@}D
* Open. You can then make changes to the template in the Source Editor. %=9yzIjbAt
*/ 5%?b5(mnD
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package com.tot.count; UlNfI}#X
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/** B$TChc3B
* MiH}VfI
* @author AXP`,H
*/ 7X{bB
public class CountBean { 6QLQ1k`
private String countType; BCUt`;q ]B
int countId; ;=+Zw1/g
/** Creates a new instance of CountData */ ,ah*!Zm.kk
public CountBean() {} k
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public void setCountType(String countTypes){ +6hl@Fm(
this.countType=countTypes; EEs-&
} WAB0e~e:|Q
public void setCountId(int countIds){ 0vuKGjK
this.countId=countIds; r}0C8(oq
} gFs/012{
public String getCountType(){ @>fO;*
return countType; h!G^dW.
} ^@`e
public int getCountId(){ 8HFXxpt[G
return countId; -*%!q$:
} 6UW:l|}4#2
} 9Ue7
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CountCache.java %8bzs?QI
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/* qfGtUkSSb
* CountCache.java 6`qr:.
* 3g0u#t{
* Created on 2007年1月1日, 下午5:01 HS\3)Ooj>
* )?B~64N,+
* To change this template, choose Tools | Options and locate the template under '9
e\.
* the Source Creation and Management node. Right-click the template and choose YWRE&MQ_
* Open. You can then make changes to the template in the Source Editor. w=D%D8 r2
*/ & &" 'dL
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package com.tot.count; t1w2u.]
import java.util.*; UOWIiu
/** w}j6.r
*
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* @author sB( `[5I
*/ s[3![
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public class CountCache { s~LZOPN
public static LinkedList list=new LinkedList(); *5y
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/** Creates a new instance of CountCache */ n{64g+
public CountCache() {} ,2,SG/BB
public static void add(CountBean cb){ XLZ j
if(cb!=null){ F)/~p&H
list.add(cb);
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} *H5PT
} xvR?~
} -@SOo"P
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CountControl.java my ;
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/* +ze}0lrEL
* CountThread.java 0R@g(
* #vj#! 1
* Created on 2007年1月1日, 下午4:57 crd|2bjp+
* _Z+jQFKJ\8
* To change this template, choose Tools | Options and locate the template under [`.3f'")j
* the Source Creation and Management node. Right-click the template and choose S<eZ d./p6
* Open. You can then make changes to the template in the Source Editor. }XCR+uAz
*/ q%-&[%l
.Vo"AuC}
package com.tot.count; >f\zCT%cf
import tot.db.DBUtils; -BA"3 S
import java.sql.*; fJLf7+q
/** #\pP2
* H(15vlOD
* @author cy) k<?,
*/ 1C_'H.q<=
public class CountControl{ :[Qp2Gg O\
private static long lastExecuteTime=0;//上次更新时间 Ap]4QqU
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 L1hD}J'$4
/** Creates a new instance of CountThread */ 'e.q
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public CountControl() {} F!7f_m0=
public synchronized void executeUpdate(){ g7xbyBo7
Connection conn=null; \|2tTvW,0
PreparedStatement ps=null; \6 \hnP
try{ 7qP4B9S
conn = DBUtils.getConnection(); (R_CUH
conn.setAutoCommit(false); ?R;nL{
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); zmf"I[)
for(int i=0;i<CountCache.list.size();i++){ /Hv*K&}M
CountBean cb=(CountBean)CountCache.list.getFirst(); ,IIZXl@
CountCache.list.removeFirst(); i8Fs0U4"
ps.setInt(1, cb.getCountId()); T3PX gL)o
ps.executeUpdate();⑴ ^|wT_k\
//ps.addBatch();⑵ WP0 #i~3*
} la'e[t7
//int [] counts = ps.executeBatch();⑶ NW{y%Z
conn.commit(); 6Z~Ya\~.g.
}catch(Exception e){ >0PUWr$8
e.printStackTrace(); f.||PH
} finally{ LthGZ|>
try{ Dd| "iA
if(ps!=null) { 0VzXDb>`
ps.clearParameters(); nQ5N=l
ps.close(); 7p)N_cJD
ps=null; aZ`<PdA
} 9nn>O?
}catch(SQLException e){} bvl~[p$W3
DBUtils.closeConnection(conn); $^}[g9]1
}
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} f
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public long getLast(){ 7}Bj|]b)~
return lastExecuteTime; }>V/H]B
} MZT6g. ny
public void run(){ a3Y{lc#z}
long now = System.currentTimeMillis(); hUVk54~l
if ((now - lastExecuteTime) > executeSep) { i{8]'fM
//System.out.print("lastExecuteTime:"+lastExecuteTime); 16I&7=S,
//System.out.print(" now:"+now+"\n"); }6).|^]\'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); :.#z
lastExecuteTime=now; "YJ[$TG
executeUpdate(); nO~b=qO
} dM Y
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else{ %c]nWR+/
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ;a|`s
} t)9]<pN%
} [s~JceUyX
} )ZGYhE
//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 [-\({<t3x
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类写好了,下面是在JSP中如下调用。 *B1x`=
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<% UP\C"\
CountBean cb=new CountBean(); YMT8p\#rp
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0<g<GQ(E
CountCache.add(cb); & g:%*>7P
out.print(CountCache.list.size()+"<br>"); 7i8eg*Gl
CountControl c=new CountControl(); *C\(wL
c.run(); e^QVn\<c
out.print(CountCache.list.size()+"<br>"); @g4Shlx|
%>