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: bZ+Hu~
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CountBean.java /de~+I5AB~
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/* PA,\o8]x
* CountData.java [LbCG
* C6D
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* Created on 2007年1月1日, 下午4:44 4]%MrSjS
* `{}DLaD9
* To change this template, choose Tools | Options and locate the template under "M %WV>
* the Source Creation and Management node. Right-click the template and choose !;Ctz'wz
* Open. You can then make changes to the template in the Source Editor. F)S?>P&
*/ T\7t#Z
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package com.tot.count; )Oj{x0{\Q
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/** Z22#lF\ N
* Bv6~!p
* @author F/df!I~
*/ ? 8S~R
public class CountBean { NnY+=#j7L
private String countType; ZM57(D
int countId; 3nUC,T%
/** Creates a new instance of CountData */ Cg^1(dBd[9
public CountBean() {} U{9yfy
public void setCountType(String countTypes){ E/>kvs%
this.countType=countTypes; sz4;hSTy
} rp!{QG
public void setCountId(int countIds){ In#m~nE[M
this.countId=countIds; [*Vo`WgbD
} V%FWZn^
public String getCountType(){ f!cYLU1e@
return countType; TF@k{_f
} _Oc\hW
public int getCountId(){ su~J:~q
return countId; nYnv.5
} Dq*O8*#*
} (;++a9GK
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CountCache.java 4ZT0~37(
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/* e:n3@T,R
* CountCache.java U%tpNWB
* N8m3Wy
* Created on 2007年1月1日, 下午5:01 &2pa9i
* cN]g^
* To change this template, choose Tools | Options and locate the template under 5VE9DTE
* the Source Creation and Management node. Right-click the template and choose A_|X54}w&
* Open. You can then make changes to the template in the Source Editor. Twk,R. O
*/ \U HI%1^
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package com.tot.count; OH` |aqN
import java.util.*; zj#8@gbh+
/** c7 O$< F
* 5
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* @author a,?u
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*/ JZoH -
public class CountCache { $HFimU,V=0
public static LinkedList list=new LinkedList(); CVGQ<,KVW
/** Creates a new instance of CountCache */ -Dr)+Y
public CountCache() {} aq.Lnbi/X
public static void add(CountBean cb){
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if(cb!=null){ 2U'Vq
list.add(cb); E~c>LF_]Q
}
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} RjGJfN{
} &MP +
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CountControl.java nztnU9OG
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/* ]4)$dQ59
* CountThread.java - ]U2G:
* xn2f!\%p
* Created on 2007年1月1日, 下午4:57 '/<f'R^
* Hni?r!8r
* 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 M}N[> ,2'
* Open. You can then make changes to the template in the Source Editor. ::p(ViYG
*/ <4D.H
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package com.tot.count; )t$o0!
import tot.db.DBUtils; k '-5&Q
import java.sql.*; (aSY.#;
/** _F tI2G9
* U3M;6j9`
* @author =.t3|5U8
*/ ^ <+V[=X
public class CountControl{ YiTVy/
private static long lastExecuteTime=0;//上次更新时间 -X,[NI3
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 L~&r.81
/** Creates a new instance of CountThread */ h0zv@,u
public CountControl() {} JnXVI!+JDL
public synchronized void executeUpdate(){ "Rr650w[
Connection conn=null; 'EkuCL
PreparedStatement ps=null; >1NE6T
try{ 1p
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conn = DBUtils.getConnection(); "uG@gV
conn.setAutoCommit(false); qnTW?c9Z5
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); lVo}DFZ
for(int i=0;i<CountCache.list.size();i++){ {4HcecT
CountBean cb=(CountBean)CountCache.list.getFirst(); DkeFDzQ5
CountCache.list.removeFirst(); U$wD'v3pw
ps.setInt(1, cb.getCountId()); t}f,j^`e
ps.executeUpdate();⑴ ~cb7]^#u1l
//ps.addBatch();⑵ "\l#q$1h
} asKAHVT(
//int [] counts = ps.executeBatch();⑶ \CZD.2p#&
conn.commit(); Yjh02wo
}catch(Exception e){ 'qiDh[ATa
e.printStackTrace(); ;.&k zzvJ
} finally{ HkdBPMs79
try{ ko`.nSZ-k
if(ps!=null) { 'XW9+jj)/
ps.clearParameters(); e>!=)6[*
ps.close(); p[7?0 (
ps=null; =~
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} {*AYhZ
}catch(SQLException e){} \jHIjFwQ
DBUtils.closeConnection(conn); w ;xbQZ|+
} m53~Ysq<
} d9.~W5^fC
public long getLast(){ m-MfFEZ
return lastExecuteTime; "aJfW
} Q;0g
public void run(){ 3\0,>L9ET@
long now = System.currentTimeMillis(); @XN|R
if ((now - lastExecuteTime) > executeSep) { M|}V6F_y
//System.out.print("lastExecuteTime:"+lastExecuteTime); @agxu-Y
//System.out.print(" now:"+now+"\n"); KU*XRZu)
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Q;y)6+VU4
lastExecuteTime=now; 3u~V&jl
executeUpdate(); %v,a3^Qu
} $`6Q\=*R/
else{ 4s7&*dJ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); u/(~ewI
} &^(4yw(~
} X@H/"B%u2
} `tEW.s%Y(6
//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 ?[c{pb,|
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类写好了,下面是在JSP中如下调用。 2dJP|T9H
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<% 0vrx5E!
CountBean cb=new CountBean(); +CXtTasP
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); n+SHkrW
CountCache.add(cb);
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out.print(CountCache.list.size()+"<br>"); nIf~ds&TT
CountControl c=new CountControl(); U~q2j#pJ
c.run(); vMeB2r<
out.print(CountCache.list.size()+"<br>"); ZFNg+H/k
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