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: XZ@>]P
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CountBean.java NS5 49S
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/* \G=bj;&eF
* CountData.java \DyKtrnm%
* gDhl-
* Created on 2007年1月1日, 下午4:44 ype"7p\
* Y:%"K
* To change this template, choose Tools | Options and locate the template under i;HH !
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* the Source Creation and Management node. Right-click the template and choose V~c(]K)-
* Open. You can then make changes to the template in the Source Editor. kGj]i@(PA4
*/ o*)@oU
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package com.tot.count;
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/** W^ClHQ"Iy
* X)NWX9^;'
* @author t>@yv#
*/ htg'tA^CtS
public class CountBean { G 4"lZM
private String countType; 83xd@-czgh
int countId; TA9dkYlE/
/** Creates a new instance of CountData */ n8?KSQy$
public CountBean() {} Hf.xd.Yw
public void setCountType(String countTypes){ 7 FIFSt
this.countType=countTypes; ,^!Zm^4,
} &"O_wd[+:
public void setCountId(int countIds){
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this.countId=countIds; Znq(R8BMW
} +cw{aI`a8
public String getCountType(){ U;>B7X;`E4
return countType; 9T]va]w?#
} C[W5d~@;E
public int getCountId(){ KPg[-d
return countId; \
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} PoY>5
} @d
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CountCache.java >2t
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/* k2wBy'M.'
* CountCache.java Z#@6#S`
* 5#BF,-Jv
* Created on 2007年1月1日, 下午5:01 \)s3b/oap
* 9OhR41B
* To change this template, choose Tools | Options and locate the template under yx 7loy$[
* the Source Creation and Management node. Right-click the template and choose ;HT0w_,
* Open. You can then make changes to the template in the Source Editor. F94V 5_[
*/ !~tnti6
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package com.tot.count; =yo=q)W
import java.util.*; 4&H+hN{3
/** kEx8+2s=M
* 0vcET(
* @author i~ROQMN1
*/ $TFTIk*uU
public class CountCache { lWIv(%/@
public static LinkedList list=new LinkedList(); j@_nI~7f}
/** Creates a new instance of CountCache */ `GP3D~
public CountCache() {} S{Rh'x\B
public static void add(CountBean cb){ i~(#S8U4d
if(cb!=null){ 69?I?,7
list.add(cb); Bac?'ypm
} -aA<.+
} my=*zziN
} Y]?Kqc
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CountControl.java 2}ag_
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/* M2a}x+5'
* CountThread.java -Zttj /K
* G|<] Ma9x
* Created on 2007年1月1日, 下午4:57 b,zR5R^D;
* ;;D%
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* To change this template, choose Tools | Options and locate the template under 6_pDe
* the Source Creation and Management node. Right-click the template and choose +|)zwe
* Open. You can then make changes to the template in the Source Editor. Z<w,UvJa
*/ T27:"LVw
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package com.tot.count; a\.//?
import tot.db.DBUtils; @ 8A{ 9i
import java.sql.*; 2f s9JP{^0
/** `x5ll;"J
* 9 Zs#Ky/
* @author (di)`D5Q
*/ 32TP Mk
public class CountControl{ \-DM-NrZ1U
private static long lastExecuteTime=0;//上次更新时间 sTJJE3TBI
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 cF-Jc}h
/** Creates a new instance of CountThread */ U<1}I.hDJ
public CountControl() {} +'!h-x1y~
public synchronized void executeUpdate(){ t- !h
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Connection conn=null; aA7S'[NjB
PreparedStatement ps=null; Yjpb+}
try{ #tCIuQ,
conn = DBUtils.getConnection(); eOO!jrT:
conn.setAutoCommit(false); C+}CU}
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); zUvB0\{q
for(int i=0;i<CountCache.list.size();i++){ B b$S^F(Xq
CountBean cb=(CountBean)CountCache.list.getFirst(); Rv0-vH.n
CountCache.list.removeFirst(); W^-hMT]uD
ps.setInt(1, cb.getCountId()); hQ\#Fhu7
ps.executeUpdate();⑴ ]v/t8`
//ps.addBatch();⑵ 39'X$!
} &3!i@2d;3f
//int [] counts = ps.executeBatch();⑶ "4J?JR
conn.commit(); :d, >d
}catch(Exception e){ ")fOup@ ^a
e.printStackTrace(); ?+5"
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} finally{ pb,{$A
try{ 4Sd+"3M
if(ps!=null) { x(exx
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ps.clearParameters(); o}5'v^"6,
ps.close(); )G}sb*+v?
ps=null; ^xBb$
} F Bd+=bx,Z
}catch(SQLException e){} FjK Ke7
DBUtils.closeConnection(conn); =M Q2sb
} O e0KAn
} OJh+[bf"
public long getLast(){ WBIQ%XB'
return lastExecuteTime; (, ;MC/l
} ][s*~VK;
public void run(){ 8^&fZL',
long now = System.currentTimeMillis(); ! hOOpZf7
if ((now - lastExecuteTime) > executeSep) { KFCQYdI`d
//System.out.print("lastExecuteTime:"+lastExecuteTime); wWp?HDl"M
//System.out.print(" now:"+now+"\n"); RlG'|xaT
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); F(0pru4u
lastExecuteTime=now; a,en8+r]
executeUpdate(); #c8"
} &lO Xi?&"
else{ D3,t6\m
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); w*]_FqE
} @]}Qh;a~
} 3hp
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} 7lnM|nD
//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 o.v,n1Nm
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类写好了,下面是在JSP中如下调用。 tSw~_s_V
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<% Dg ?Ho2ih
CountBean cb=new CountBean(); @U7U?.p
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); {EiG23!qV
CountCache.add(cb); }WBm%f
out.print(CountCache.list.size()+"<br>"); T%z!+/=&^
CountControl c=new CountControl(); *X"F: 7
c.run(); 2n"*)3Qj
out.print(CountCache.list.size()+"<br>"); >?:i6&4o
%>