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: $Ygue5{c
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CountBean.java -ze J#B)C
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/* CU~PT.
* CountData.java MUwMb!Z.s
* onV>.7sG
* Created on 2007年1月1日, 下午4:44 Fs^Mw
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* Y|/ 8up
* To change this template, choose Tools | Options and locate the template under VS|2|n1<6
* the Source Creation and Management node. Right-click the template and choose DIUjn;>k8
* Open. You can then make changes to the template in the Source Editor. o,wUc"CE
*/ 7mfS*aCb
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package com.tot.count; f<6lf7qzC
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/** *n"{J(Jt`
* d0 /#nz
* @author ll?X@S
*/ (Awm9|.{+
public class CountBean { G]aOHJ:.
private String countType; t3^&;&[
int countId; U`s{Jm
/** Creates a new instance of CountData */ 3= ;<$+I6
public CountBean() {} R/a*LSe@&
public void setCountType(String countTypes){ (4-CF3D
this.countType=countTypes; CTA3*Gn
} (uidNq
public void setCountId(int countIds){ hFBe,'3M
this.countId=countIds; ]}X
} J?$,c4;W2
public String getCountType(){ '4<1 1(U
return countType; P1f[%1
} -D~%|).'
public int getCountId(){ |vzl. ^"-
return countId; K~EmD9
} |e0`nn=
} /_ajaz%
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CountCache.java Uoix
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/* ~7Ux@Sx;
* CountCache.java yEQs:v6L~
* J4U1t2@)9
* Created on 2007年1月1日, 下午5:01 2I{"XB
* Oa>Ppldeg
* To change this template, choose Tools | Options and locate the template under mB)bcuPv
* the Source Creation and Management node. Right-click the template and choose 1m0c|ckb
* Open. You can then make changes to the template in the Source Editor. Z<{QaY$"
*/ dUdT7ixo
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package com.tot.count; E&:,oG2M
import java.util.*; <ZR9GlIr
/** \z}
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* +8ZF"{y
* @author q-d:TMkc
*/ Y`wSv NU
public class CountCache { 7E!5G2XX~~
public static LinkedList list=new LinkedList(); cQ_Hp
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/** Creates a new instance of CountCache */ "5$B>S(Q
public CountCache() {} UJ6v(:z<
public static void add(CountBean cb){ jZrq{Z<
if(cb!=null){ ~WV"SaA)*U
list.add(cb); &PtJ$0%q
} "@8li^
} IMONgFBS
} kB%JNMF{A
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CountControl.java 7"D.L-H
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/* C$)onk
* CountThread.java l%i+cO D
* x'R`.
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* Created on 2007年1月1日, 下午4:57 \Y}8S/]
* mpJ#:}n
* To change this template, choose Tools | Options and locate the template under D^;Uq8NDKq
* the Source Creation and Management node. Right-click the template and choose @"H>niG
* Open. You can then make changes to the template in the Source Editor. "" ZQ/t\
*/ Aq7osU1B
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package com.tot.count; 0_t!T'jr7
import tot.db.DBUtils; b>JDH1)
import java.sql.*; Jxm.cC5z.
/** NQ2E
* D.XvG _
* @author $ L]lHji
*/ ~61v5@
public class CountControl{ ~W]TD@w
private static long lastExecuteTime=0;//上次更新时间 +=8VTCn?
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 l1Fc>:o{
/** Creates a new instance of CountThread */
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public CountControl() {} m`r(p"
public synchronized void executeUpdate(){ iOO)Q\
Connection conn=null; hY8reQp1
PreparedStatement ps=null; VyGJ=[ ]
try{ N ZSSg2TX#
conn = DBUtils.getConnection(); UFuX@Lu0
conn.setAutoCommit(false); $iz|\m
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 4+ Z]3oIRE
for(int i=0;i<CountCache.list.size();i++){ 5/Uy{Xt
CountBean cb=(CountBean)CountCache.list.getFirst(); 0{ R=9wcc
CountCache.list.removeFirst(); '2^Q1{ :\
ps.setInt(1, cb.getCountId()); 6)Lk-D
ps.executeUpdate();⑴ :9 ^*
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//ps.addBatch();⑵ kMd.h[X~
} k$^`{6l
//int [] counts = ps.executeBatch();⑶ `PH{syz
conn.commit(); VW4r{&rS
}catch(Exception e){ B^9j@3Ux
e.printStackTrace(); czd~8WgOa
} finally{ u;c?d!E
try{ h'F=YF$o
if(ps!=null) { {/:x5l8
ps.clearParameters(); Z?QC!bWb
ps.close(); +K4}Dmg
ps=null; #;nYg?d=
} [cp+i^f
}catch(SQLException e){} J/*`7Pd
DBUtils.closeConnection(conn);
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} JaGtsi9%.
} E?0%Z&1h
public long getLast(){ |
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return lastExecuteTime; XOS[No~
} @MCg%Afw
public void run(){ g}',(tPMZ
long now = System.currentTimeMillis(); K(Bf2Mfq
if ((now - lastExecuteTime) > executeSep) { 8-77d^cprR
//System.out.print("lastExecuteTime:"+lastExecuteTime); w+CA1q<
//System.out.print(" now:"+now+"\n"); n7-6-
#
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); <e</m)j
lastExecuteTime=now; B`J~^+`[*
executeUpdate(); ?(i{y~
} *!7O~yQ
else{ d-dEQKI?;
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 0:Ol7
} 3'u-'
} [u*5z.^
} .0]<k,JZZ
//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 "a U
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类写好了,下面是在JSP中如下调用。 W:L
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<% '1s0D]
CountBean cb=new CountBean(); :Fvrs(
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); u:_,GQ )\
CountCache.add(cb); ;;N9>M?b
out.print(CountCache.list.size()+"<br>"); OpYY{f
CountControl c=new CountControl(); AkQ~k0i}b
c.run(); !d0kV,F:
out.print(CountCache.list.size()+"<br>"); %OOl'o"V{s
%>