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>Ox(MG
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CountBean.java s."N7F
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/* G
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* CountData.java dlZ2iDQ%
* p {.6
* Created on 2007年1月1日, 下午4:44 }vP(SF6
* PpLhj
* To change this template, choose Tools | Options and locate the template under $P8AU81
* the Source Creation and Management node. Right-click the template and choose >U\P^yU
* Open. You can then make changes to the template in the Source Editor. x3 ( _fS
*/ Xep2)3k>
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package com.tot.count; <h+UC# .x
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/** @+Nf@LJ
* 7;.Iat9gMf
* @author keQRS+9
*/ /Trbr]lWy
public class CountBean { rR{KnM
private String countType; 8qfXc
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int countId; Ur1kb{i
/** Creates a new instance of CountData */ mss.\
public CountBean() {} )3|a_
public void setCountType(String countTypes){ iM1E**WCtv
this.countType=countTypes; m#_M"B.cm
} ;ioF'ov
public void setCountId(int countIds){ 'F/uD1;
this.countId=countIds; ~-sG&u>
} PN J&{4wY
public String getCountType(){ S5H}
return countType; 5K&A2zC|
} g&.OJ
public int getCountId(){ ;1_3E2E$
return countId; (6}7z+
} 77+3CME{'
} o7PS1qcya<
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CountCache.java JXt_
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/* E 8$S0u;`
* CountCache.java #Lk~{
* b8%TwYp
* Created on 2007年1月1日, 下午5:01 8aM\B%NGWi
* NCo!n$O1~
* To change this template, choose Tools | Options and locate the template under T>hm\ !
* the Source Creation and Management node. Right-click the template and choose 3-Xd9ou
* Open. You can then make changes to the template in the Source Editor. _2<UcC~
*/ 1BP/,d |+
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package com.tot.count; ?h|DeD!s
import java.util.*; LU@1Gol
/** $|[N3
* Z?&ZgaSz
* @author w7q6v>
*/ GlC (uhCpV
public class CountCache { U(OkTJxv+
public static LinkedList list=new LinkedList(); 79o=HiOF99
/** Creates a new instance of CountCache */ 23'{{@30
public CountCache() {} ]!jfrj
public static void add(CountBean cb){ ;"RyHow
if(cb!=null){ JFNjc:4{0
list.add(cb); \;Q!}_ K
} XVo+ <&
} }1CvbB%,A
} Cy5iEI#
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CountControl.java 3rJ LLYR
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/* ?s)6 YF
* CountThread.java zF? 6"
* TT#V'r\
* Created on 2007年1月1日, 下午4:57 <F-IF7>a
* U 17=/E
* To change this template, choose Tools | Options and locate the template under 3Q7PY46
* the Source Creation and Management node. Right-click the template and choose pbwOma2
* Open. You can then make changes to the template in the Source Editor. w`M`F<_\:
*/ cbzS7q<)
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package com.tot.count; ;'[?H0Jw'
import tot.db.DBUtils; a^[s[j#^,
import java.sql.*; yWT1CID
/** uGYH4
* /V]i3ac
* @author v5?ct?q
*/ #i.BOQxS
public class CountControl{ o,0
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private static long lastExecuteTime=0;//上次更新时间 adgd7JjI*
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 CU*;>h1~u
/** Creates a new instance of CountThread */ r5$!41
public CountControl() {} "W9z>ezp
public synchronized void executeUpdate(){ i 2[8^o`_
Connection conn=null; x~D8XN{
PreparedStatement ps=null; t47;X}y f
try{ N\?__WlBK7
conn = DBUtils.getConnection(); EF9Y=(0|
conn.setAutoCommit(false); dAOJ:
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); A
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for(int i=0;i<CountCache.list.size();i++){ Aq>?G+
CountBean cb=(CountBean)CountCache.list.getFirst(); + kF%>F]
CountCache.list.removeFirst(); `ooHABC
ps.setInt(1, cb.getCountId()); e$rPXRf
ps.executeUpdate();⑴ !>kg:xV
//ps.addBatch();⑵ g$/7km{TP
} EEx:Xk%5hX
//int [] counts = ps.executeBatch();⑶ "zqa:D26
conn.commit(); cveQ6
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}catch(Exception e){ %):pfM;b
e.printStackTrace(); )%8st'
} finally{ V<ilv<
try{ 3RFU
if(ps!=null) { $uRi/%Q9
ps.clearParameters(); C!6D /S
ps.close(); OcC|7s",
ps=null; r-]%R:U*
} n(SeJk%>9
}catch(SQLException e){} :$P1ps3B
DBUtils.closeConnection(conn); 'cc{sjG
} wuSotbc/
} 'UuHyC2Ha3
public long getLast(){ z+zEH9.'
return lastExecuteTime; HTm`_}G9
} 1vJj?Uqc
public void run(){ L{&Yh|}
long now = System.currentTimeMillis(); TWfkr
if ((now - lastExecuteTime) > executeSep) { nm%7 e!{m
//System.out.print("lastExecuteTime:"+lastExecuteTime); mSk";UCn
//System.out.print(" now:"+now+"\n"); &!wtH
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); t7,$u-
lastExecuteTime=now; wZKmU
executeUpdate(); 0eK>QZ_
} jTW8mWNk]
else{ z 8#{=e
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); K @:t6
} 38:5g_
} vRDs~'f
} BhiOV_}Hn
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 m5,&;~
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类写好了,下面是在JSP中如下调用。 ?H_>?,^
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<% <@0S]jy
CountBean cb=new CountBean(); (''w$qq"D
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); = U[$i"+
CountCache.add(cb); 6(ER$
out.print(CountCache.list.size()+"<br>"); BE54L+$p
CountControl c=new CountControl(); C+dz0u3s
c.run(); I\IDt~
out.print(CountCache.list.size()+"<br>"); >Qg-dJt[
%>