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: ObzFh?W
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CountBean.java
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/* \jCN ]A<
* CountData.java 9\S,$A{{*
* ,T;T%/
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* Created on 2007年1月1日, 下午4:44 mJYG k_ua
* C.(<IcSG
* To change this template, choose Tools | Options and locate the template under zEMZz$Y
* the Source Creation and Management node. Right-click the template and choose \T:*tgU
* Open. You can then make changes to the template in the Source Editor. &0k`=?v$
*/ 3jzmiS]
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package com.tot.count; iQ8T3cC+
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/** ph~d%/^jI
* u+Sj#iZ
* @author HU47S
*/ (p!w`MSv
public class CountBean { ypy
private String countType; =}OcMM`f
int countId; 3T)_(SM"
/** Creates a new instance of CountData */ 5STk"
public CountBean() {} {9;x\($&a
public void setCountType(String countTypes){ 3'xmq
this.countType=countTypes; [;LP6n7v
} }c@duf-l
public void setCountId(int countIds){ dUc([&
this.countId=countIds; N${Wh|__^l
} h~-cnAMt
public String getCountType(){ |FP@NUX\
return countType; Cb
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} z>A;|iL
public int getCountId(){ WCL#3uYk"
return countId; M}\p/r=
} K]H [A,
} m;oCi}fL
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CountCache.java O3En+m~3n)
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/* qL2Sv(A Z!
* CountCache.java m2>$)\-;
* )>r sX)
* Created on 2007年1月1日, 下午5:01 X ApSKJ
* D&|HS!
* To change this template, choose Tools | Options and locate the template under v:zKn[;o
* the Source Creation and Management node. Right-click the template and choose mBON>Z[4.
* Open. You can then make changes to the template in the Source Editor. ^"GDaMF
*/ ~@%#eg
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package com.tot.count; v&3 Oc
import java.util.*; 9FcH\2J
/** 9w}_CCj3
* X(qs]:
* @author ]\6*2E{1m
*/ /:+MUw7~
public class CountCache { v%4zP%4Ak[
public static LinkedList list=new LinkedList(); * amZ
/** Creates a new instance of CountCache */ 4Pkl()\c
public CountCache() {} :} N;OS _
public static void add(CountBean cb){ }:1*@7eR
if(cb!=null){ (yv)zg9
list.add(cb);
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} 7f]O /
} vhz Q.>
} %h4|$
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CountControl.java UYkuz
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/* gI{56Z
* CountThread.java Ur,{ZGm
* "VI2--%v3
* Created on 2007年1月1日, 下午4:57 r[4dGt
* ,nGZ(EBD
* To change this template, choose Tools | Options and locate the template under K'zBDrkW-x
* the Source Creation and Management node. Right-click the template and choose o)sX?IiC
* Open. You can then make changes to the template in the Source Editor. 3bZ:*6W.6
*/ :IRQouTf:,
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package com.tot.count; ]>oI3&6s
import tot.db.DBUtils; v])R6-T-
import java.sql.*; JVq`v#8
/** XEb+Z7L 1
* T&u25"QOf
* @author 6r }w
*/ ?V$@2vBVX4
public class CountControl{ H5/w!y@
private static long lastExecuteTime=0;//上次更新时间 y;ymyy&
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 e?\34F
/** Creates a new instance of CountThread */ `XK#sCC
public CountControl() {} KD73Aw
public synchronized void executeUpdate(){ N51WY7
Connection conn=null; YE[{Y(5;q
PreparedStatement ps=null; 9YVr9BM'K
try{ 6UAw9
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conn = DBUtils.getConnection(); jM;?);Dd
conn.setAutoCommit(false); CQI\/oaO
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); o0#zk
for(int i=0;i<CountCache.list.size();i++){ IIUTo
CountBean cb=(CountBean)CountCache.list.getFirst(); XBN,{
CountCache.list.removeFirst(); szas(7kDS
ps.setInt(1, cb.getCountId()); n~'cKy)m
ps.executeUpdate();⑴ $x;(C[
//ps.addBatch();⑵ an,JV0
} 2,e>gP\]
//int [] counts = ps.executeBatch();⑶ !DZ4C.
conn.commit(); T~)zgu%q_
}catch(Exception e){ +W#["%kw
e.printStackTrace(); gbu@&
} finally{ .(X!*J]G
try{ 2PQY+[jx
if(ps!=null) { =e|
ps.clearParameters(); %40+si3c
ps.close(); (&xIBF_6
ps=null; tN-B`d1
} ^k4 n
}catch(SQLException e){} O+PRP"$g"
DBUtils.closeConnection(conn); ?RU_SCp-
} ,Laz515
} 2hFOwI
public long getLast(){ C0-,<X
return lastExecuteTime; ;;<[_gp,E
} >IEc4
public void run(){ zD):
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long now = System.currentTimeMillis(); \5R>+[n!
if ((now - lastExecuteTime) > executeSep) { ^/"2s}+
//System.out.print("lastExecuteTime:"+lastExecuteTime); 3TF'[(K=
//System.out.print(" now:"+now+"\n"); KK41I8Mw
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); L]QBh\
lastExecuteTime=now; -14~f)%NQ*
executeUpdate(); m}GEx)Y D
} QR*{}`+l
else{ ^s6C']q *O
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); rj-Q+rgup
} jU_#-<'r
} 6d%)MEM
} `!7QegJa"
//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 $[g8j`or!
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类写好了,下面是在JSP中如下调用。 `fUPq
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<% nWsR;~pK
CountBean cb=new CountBean(); u\P)x~-TM
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); fhbILg
CountCache.add(cb); T[]kun
out.print(CountCache.list.size()+"<br>"); "MU)8$d
CountControl c=new CountControl(); g%2twq_
c.run(); hnnPi
out.print(CountCache.list.size()+"<br>"); 73tWeZ8rvx
%>