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: $m`?x5rL8
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CountBean.java u8pJjn;
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/* G>{Bij44
* CountData.java xU#f>@v!
* * B!uYP
* Created on 2007年1月1日, 下午4:44 {J2*6_
* ~6`HJ
* To change this template, choose Tools | Options and locate the template under +E7s[9/r
* the Source Creation and Management node. Right-click the template and choose -QL_a8NL
* Open. You can then make changes to the template in the Source Editor. {D1"bDZ
*/ 4l+"J:,
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package com.tot.count; oLEqy
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/** 53d8AJ_@X
* Jrd:6Z
* @author v*'dA^Q
*/ 5BCHWX*y
public class CountBean { Hc1S:RW
private String countType; :T(3!}4
int countId; )J4XM(
/** Creates a new instance of CountData */ hjywYd]8
public CountBean() {} GU'/-6-T
public void setCountType(String countTypes){ '#REbY5ev
this.countType=countTypes; "ewSh<t
} Fyy)665x/
public void setCountId(int countIds){ A+*M<W
this.countId=countIds; !6hUTjhW7z
} _,:gSDW|
public String getCountType(){ ( /{Wu:e
return countType; hER]%)#r
} ,$ L>
public int getCountId(){ I/D(gY06<
return countId; H(U`S
} ,)3%@MwO
} [k-Q89
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CountCache.java wP.b2X_V
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/* HV@C@wmg
* CountCache.java Su99A. w
* d 6 t#4!
* Created on 2007年1月1日, 下午5:01 ?yop#tjCbY
* rf_(pp)
* To change this template, choose Tools | Options and locate the template under fB+4mEG@
* the Source Creation and Management node. Right-click the template and choose (055>D6
* Open. You can then make changes to the template in the Source Editor. <&:OSd:%
*/ v0)I rO
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package com.tot.count; -J8&!S8 X
import java.util.*; 5hwe ul>S
/** f
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* v<
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* @author F)_zR
*/
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public class CountCache {
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public static LinkedList list=new LinkedList(); C&Rv$<qc
/** Creates a new instance of CountCache */ T$[50~
public CountCache() {} w.w(*5[
public static void add(CountBean cb){ t]LOBy-Kv
if(cb!=null){ !5lb+%7
list.add(cb); gE$D#PZa
} xi|T7,\X
} c:(Xkzj
} %O]]La
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CountControl.java yO\.dp
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/* 8D3|}z?
* CountThread.java &`+tWL6L
* RV^
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* Created on 2007年1月1日, 下午4:57 8i:E$7e tH
* ,MH/lQq%
* To change this template, choose Tools | Options and locate the template under
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* the Source Creation and Management node. Right-click the template and choose *HiN:30DZ
* Open. You can then make changes to the template in the Source Editor. wq$+m(
*/ XS+2OutVo
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package com.tot.count; vz'/]E
import tot.db.DBUtils; XFJGL!wWm[
import java.sql.*; jpijnz{M
/** @@->A9'L
*
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* @author ]\DZW4?'
*/ [t#xX59
public class CountControl{ 8NCu;s
private static long lastExecuteTime=0;//上次更新时间 66ULR&D8
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 PM]|S`
/** Creates a new instance of CountThread */ fCC^hB]'
public CountControl() {} RLl*@SEi"
public synchronized void executeUpdate(){
X0a)6HZ{
Connection conn=null; 8SH&b8k<<
PreparedStatement ps=null; ?r
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try{ +d/V^ <#
conn = DBUtils.getConnection(); H!N`hEEj>
conn.setAutoCommit(false); ZSWKVTi
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 'x/pV5[hQ
for(int i=0;i<CountCache.list.size();i++){ 'Lm\ r+$F
CountBean cb=(CountBean)CountCache.list.getFirst(); W}^X;f
CountCache.list.removeFirst(); zsM3
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ps.setInt(1, cb.getCountId()); t5t!-w\M$+
ps.executeUpdate();⑴ g~ubivl2
//ps.addBatch();⑵ ~)ut"4
} VINb9W}G[
//int [] counts = ps.executeBatch();⑶ {\:"OcP #
conn.commit(); |.]sL0;4Z
}catch(Exception e){ GnT Cq_\
e.printStackTrace(); Owd{;
} finally{ _#;UXAi
try{ wz[Xay9jW
if(ps!=null) { rnNB!T
ps.clearParameters(); :{7gZ+*
ps.close(); ?rauhTVnJ
ps=null; BOc2<M/\
} LR`]C]
}catch(SQLException e){} dV/ ^@[
DBUtils.closeConnection(conn); faTp|T`nY
} OoIs'S-Z#
} sKu/VAh
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public long getLast(){ +g.lLb*#
return lastExecuteTime; g/3t@7*<
} <D}yqq@|
public void run(){ |FED<
long now = System.currentTimeMillis(); 4eD>DW
if ((now - lastExecuteTime) > executeSep) { QYB66g:
//System.out.print("lastExecuteTime:"+lastExecuteTime); qS|ns'[
//System.out.print(" now:"+now+"\n"); UO~Xzx!e
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); /9QC$Z):<
lastExecuteTime=now; pc+'/~
executeUpdate(); ,M?K3lG\g[
} *OM+d$l!
else{ G!<-9HA5
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Sm5T/&z
} BQo$c~
} "A9qC*6[
} Pl/}`H:R&
//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 q0sdL86
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类写好了,下面是在JSP中如下调用。 Ea<kc[Q
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<% wk9qyv<
CountBean cb=new CountBean(); ;N(9nX}%)
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); GS)4,.
CountCache.add(cb); c9/&A
out.print(CountCache.list.size()+"<br>"); %96l(JlJ)B
CountControl c=new CountControl(); HI\V29
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c.run(); ;0"p)O@s04
out.print(CountCache.list.size()+"<br>"); 'nQQqx%v
%>