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: y:6'&`L
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CountBean.java .0*CT:1=0
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/* UEYM;$_@4o
* CountData.java kI[O {<kQ
* }.|5S+J?[
* Created on 2007年1月1日, 下午4:44 U"Ob@$ROFy
* [#*?uu+
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* To change this template, choose Tools | Options and locate the template under ';CuJXAj
* the Source Creation and Management node. Right-click the template and choose ~1]2A[`s!
* Open. You can then make changes to the template in the Source Editor. -$MC
*/ u$@I/q,ou
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package com.tot.count; kpreTeA]
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/** pZJQKTCG
* !}Ou|r4_
* @author FC-*?
*/ 41Q
public class CountBean { Y l3[~S
private String countType; }GNH)-AG)$
int countId; ?;#3U5$v
/** Creates a new instance of CountData */ J]^gF|
public CountBean() {} 96E7hp !:
public void setCountType(String countTypes){ 3%4Mq6Q`
this.countType=countTypes;
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} $cpQ7
public void setCountId(int countIds){ 3!w>"h0(
this.countId=countIds; TKBK3N
} f(MHU
public String getCountType(){ w7?9e#>Z
return countType; 714nUA872
} 6{r[ Dq
public int getCountId(){ adr^6n6v
return countId; 0]w[wc
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} h)RM9813<
} c1!/jTX$
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CountCache.java
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/* xdU
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* CountCache.java w8#>xV^~
* v%~ViOgL\
* Created on 2007年1月1日, 下午5:01 0Lz56e'j
* c(g^*8Pb
* To change this template, choose Tools | Options and locate the template under ef;="N
* the Source Creation and Management node. Right-click the template and choose Hwc8i"{9y\
* Open. You can then make changes to the template in the Source Editor. N6
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*/ >@e%,z
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package com.tot.count; `a-T95IFy
import java.util.*; >b](v)
/** ^M5uLm-_s
* 0(f;am0y
* @author \~j(ui|
*/ R:m=HS_
public class CountCache { `ViNSr):J
public static LinkedList list=new LinkedList(); /j\TmcnU^
/** Creates a new instance of CountCache */ %=
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public CountCache() {} c0p=/*s(
public static void add(CountBean cb){ `;2`H, G'
if(cb!=null){ 7+r5?h|
list.add(cb); ?\VN`8Yb
} b:I5poI3
} ew ['9
} .u3W]5M|
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CountControl.java ~mo`
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/* X_8NW,
* CountThread.java r(CL=[
* %d\+(:uu/
* Created on 2007年1月1日, 下午4:57 yvwcXNXR@
* (W/UR9x)|d
* To change this template, choose Tools | Options and locate the template under ^P`'qfZ
* the Source Creation and Management node. Right-click the template and choose ]>T/Gl1
* Open. You can then make changes to the template in the Source Editor. y^BM*C I
*/ <L#r6y~H
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package com.tot.count; YL0RQa
import tot.db.DBUtils; - & r{%7
import java.sql.*; ;KN@v5`p
/** Bn:sN_N
* 8}@a?QS(&
* @author 7^X_tQf
*/ ZA@"uqa 6b
public class CountControl{ sg\jC#
private static long lastExecuteTime=0;//上次更新时间 dBn.DU*B
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 p4_uY7^6
/** Creates a new instance of CountThread */ j'n= Xh
public CountControl() {} "ET"dMxU
public synchronized void executeUpdate(){ HEN9D/O=
Connection conn=null; 1!#ZEI C
PreparedStatement ps=null; a@1gMZc*
try{ 3|3lUU\I
conn = DBUtils.getConnection(); m!(K
conn.setAutoCommit(false); CB)#;
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ')<$AMy1
for(int i=0;i<CountCache.list.size();i++){ c?S402M}
CountBean cb=(CountBean)CountCache.list.getFirst(); }qPo%T
CountCache.list.removeFirst(); aH~"hB^e
ps.setInt(1, cb.getCountId()); u1<kdTxA
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ps.executeUpdate();⑴ U5=J;[w}N
//ps.addBatch();⑵ `BY`ltW
} \ S R
//int [] counts = ps.executeBatch();⑶ en)DN3
conn.commit(); :{2$X|f
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}catch(Exception e){ .jw)e!<\N
e.printStackTrace(); yD"sYT
} finally{ RR|Eqm3)
try{ Fsh-a7Qp
if(ps!=null) { /2 N%Z
ps.clearParameters(); ?9A[;j|a0
ps.close(); Q<qIlNE
ps=null; In2D32"F
} mHy]$Z
}catch(SQLException e){} \Qn8"I83AV
DBUtils.closeConnection(conn); MiRB*eA
} D![Twlll
} P@#6.Bb#V
public long getLast(){ xB#E&}Ho
return lastExecuteTime; q[lqEc
} 8:bNFgJD
public void run(){ zO,sq%vQn'
long now = System.currentTimeMillis(); Khl7Ez
if ((now - lastExecuteTime) > executeSep) { *RO ~%g
//System.out.print("lastExecuteTime:"+lastExecuteTime); *(rE<
//System.out.print(" now:"+now+"\n"); V<7Gd8rDMM
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); )NK2uD
lastExecuteTime=now; !p$V7pFu6
executeUpdate(); >vhyKq|g<
} Z:Wix|,ONS
else{ ~A)$= "
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); dGg+[?
} U&NOf;h$
} "?!IPX2\S
} '"EOLr\Z,
//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 6yU~^))bx
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类写好了,下面是在JSP中如下调用。 tkmW\
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<% LuVj9+1 S
CountBean cb=new CountBean(); >cp9{+#f
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); y-U(`{[nM
CountCache.add(cb); jL# ak V
out.print(CountCache.list.size()+"<br>"); Z7v~;JzC#
CountControl c=new CountControl(); _:z~P<%s
c.run(); yQ}~ aA#h
out.print(CountCache.list.size()+"<br>"); d dPJx<
%>