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: =r w60B
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CountBean.java bc+~g>o
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/* &U_YDUQ'L
* CountData.java ]lT8Z-h@
* 3YKJN4
* Created on 2007年1月1日, 下午4:44 <7U\@si4
* \&{a/e2:S
* To change this template, choose Tools | Options and locate the template under M2pe*z
* the Source Creation and Management node. Right-click the template and choose J$aE:g6'
* Open. You can then make changes to the template in the Source Editor. SG5GJCkc
*/ [`F}<L."
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package com.tot.count; 5%qq#;[n
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/** 9.:]eL
* &dH[lB
* @author Su4&qY
*/ Aof)WKo
public class CountBean { R6(sWN-
private String countType; nrhzNW>]
int countId; |S0w>VH>
/** Creates a new instance of CountData */ qjcPJ
public CountBean() {} @r.w+E=
public void setCountType(String countTypes){ n7|8`?R^
this.countType=countTypes; Az+k8=?
} [~aRA'qJ{V
public void setCountId(int countIds){ Q)/V>QW
this.countId=countIds; H^VNw1.
} S7B7'[ru
public String getCountType(){ h_( #U)z_3
return countType; /?ZO-]q
} B4D#TlB
public int getCountId(){ K@f@vyw]
return countId; ifXGH>C
} L:.z
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} Bf21u9
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CountCache.java ; ,vGw<|o
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/* .83{NF
* CountCache.java Cr7T=&L
* wV604eO(
* Created on 2007年1月1日, 下午5:01 N4[`pXM6
* gNWTzz<[f>
* To change this template, choose Tools | Options and locate the template under [%0{7pz}
* the Source Creation and Management node. Right-click the template and choose rN3qTp
* Open. You can then make changes to the template in the Source Editor. g3Xa b
*/ l.@v@T(/
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package com.tot.count; +HXR ))X
import java.util.*; 8t)?$j$
/** @TQzF-%#7
* o]@Mg5(8Q
* @author 5LX%S .CW
*/ !y$:}W?_
public class CountCache { r6b;v2!8
public static LinkedList list=new LinkedList(); cXd?48O
/** Creates a new instance of CountCache */ FxFRrRRH@
public CountCache() {} up@I,9C/
public static void add(CountBean cb){ 8PB 8h
if(cb!=null){ L0Ycf|[s,
list.add(cb); +W%3VV$
} *el~sor;S
} {!L25
} NimW=X;c
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CountControl.java ;4'pucq5/
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/* tP.jJC~
* CountThread.java NQmdEsK
* sGp]jqX2,m
* Created on 2007年1月1日, 下午4:57 m-HL7&iG$
* SWLt5dV
* To change this template, choose Tools | Options and locate the template under iW9o-W
a
* the Source Creation and Management node. Right-click the template and choose +F4SU(T
* Open. You can then make changes to the template in the Source Editor. q` 0wG3
*/ -cONC9=
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package com.tot.count; n/6qc3\5i
import tot.db.DBUtils; E*Z # fa
import java.sql.*; }T~}W8H
/** @}<b42
* S]x\Asj;w
* @author T&q0TBT
*/ \3WQ<t)W
public class CountControl{ s# 9*`K
private static long lastExecuteTime=0;//上次更新时间 aGml!N5'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Pm/Rc
/** Creates a new instance of CountThread */ ,+>JQ82
public CountControl() {} cuoZ:Wh
public synchronized void executeUpdate(){ 6ec#3~ Y]
Connection conn=null; b6?&h:{k
PreparedStatement ps=null; (MGYX_rD
try{ EY^+ N>
conn = DBUtils.getConnection(); X-<l+WP
conn.setAutoCommit(false); v;o/M6GL5
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); c9:8KMF)
for(int i=0;i<CountCache.list.size();i++){
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CountBean cb=(CountBean)CountCache.list.getFirst(); E;bv;RUio
CountCache.list.removeFirst(); NZL$#bRB
ps.setInt(1, cb.getCountId()); mHF?t.y
ps.executeUpdate();⑴ "qdEu KI
//ps.addBatch();⑵ %F}i2!\<L
} l<)k`lrMX4
//int [] counts = ps.executeBatch();⑶ !zQbF&>
conn.commit(); hd1aNaF-
}catch(Exception e){ l3:2f-H
e.printStackTrace(); skP'- ^F~
} finally{ "j/jhe6
try{ j[${h,p?
if(ps!=null) { KQTv5|$?
ps.clearParameters(); H7{I[>:
ps.close(); $]<wQH/?_
ps=null; ]99@Lf[^f
} [J8;V|v
}catch(SQLException e){} 045_0+r"@
DBUtils.closeConnection(conn); REGk2t.L
} LEC=@) B
} I&9Itn p$
public long getLast(){ _J X>#h
return lastExecuteTime; `{1~]?-&
} @q"HZO[
public void run(){ 8'*/|)Hn
long now = System.currentTimeMillis(); 8P*d
if ((now - lastExecuteTime) > executeSep) { `kYcTFk
//System.out.print("lastExecuteTime:"+lastExecuteTime); s3[\&zt
//System.out.print(" now:"+now+"\n"); eL_Il.:
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |"
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lastExecuteTime=now; U[{vA6
executeUpdate(); V [Wo9Y\
} a7}O.NDf
else{ 3_ ZlZ_Tq
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); [tk6Kx8a
} M.9w_bW]#D
} WRp0.
} dUH+7.\
//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 KP&$Sl
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类写好了,下面是在JSP中如下调用。 |@BX*r
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<% vMzBp#MT
CountBean cb=new CountBean(); i :|e#$x
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); UuCRQN H
CountCache.add(cb); 2QgD<
out.print(CountCache.list.size()+"<br>"); 9/h[(qvT
CountControl c=new CountControl(); >0JCu^9
c.run(); J,*+Ak
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out.print(CountCache.list.size()+"<br>"); hrW2#v
%>