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: _:Jp*z
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CountBean.java hUT^V(
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/* ~@4ZV
* CountData.java 6%\Q*r*N
* l/png:
* Created on 2007年1月1日, 下午4:44 24jtJC,7
* o!toO&=
* To change this template, choose Tools | Options and locate the template under ^>X)"'0+
* the Source Creation and Management node. Right-click the template and choose c@ZS|U*(
* Open. You can then make changes to the template in the Source Editor. w*u{;v#
*/ 8 ih;#I=q
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package com.tot.count; Q-8'?S
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/** '-PMF~~S
* Vp]D
* @author "rx^M*"
*/ FJf~vAQ
public class CountBean { 46K&$6eN
private String countType; sP?$G8-^
int countId; W[>iJJwz
/** Creates a new instance of CountData */ )v52y8G-p
public CountBean() {}
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public void setCountType(String countTypes){ \/*Nf?;
this.countType=countTypes; Wyq~:vU.S
} .;HIEj zq
public void setCountId(int countIds){ 0Ws;|Yg
this.countId=countIds; :/v,r=Y9p
} cZgMA8
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public String getCountType(){ n|x$vgb
return countType; AUxM)H
} (/SGT$#8
public int getCountId(){ jWXR__>.
return countId; %0yS98']g
} ^}o7*
} %-#
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CountCache.java Ts(t:^
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/* -Aa]aDAz68
* CountCache.java /Fe:h>6
* e2k4[V
* Created on 2007年1月1日, 下午5:01 79SqYe=&uy
* @n7t?9Bx
* To change this template, choose Tools | Options and locate the template under L\ }Pzxn
* the Source Creation and Management node. Right-click the template and choose ]am~aJ|L
* Open. You can then make changes to the template in the Source Editor. 6X7s 4
*/ g5[ D&
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package com.tot.count; tx0Go'{
import java.util.*; WHUT/:?f
/** $T?*0"Mj[
* g/8.W
* @author )RwBg8
*/ ?0rOcaTY
public class CountCache { v<;: 0
public static LinkedList list=new LinkedList(); rQ
/** Creates a new instance of CountCache */ %M{k.FE(
public CountCache() {} Mlv<r=E
public static void add(CountBean cb){ )?w&oIj5
if(cb!=null){ g.x=pt
list.add(cb); /
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} a-]hW=[
} K1T1@ j
} e(yQKwVD
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CountControl.java 5M%,N-P^
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/* E@w[
* CountThread.java 'h-3V8m^e
* O)`fvpVU
* Created on 2007年1月1日, 下午4:57 d5DP^u
* $]@O/[
* To change this template, choose Tools | Options and locate the template under gbm0H-A:*
* the Source Creation and Management node. Right-click the template and choose }B y)y;~
* Open. You can then make changes to the template in the Source Editor. Y4mC_4EU
*/ [E>R.Oe
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package com.tot.count; ]7a;jNQu
import tot.db.DBUtils; [6D>f?z
import java.sql.*; FU%~9NKX
/** GR,J0LT
* Aoj6k\YX
* @author ' _B_&is
*/ ]o-Fi$h!
public class CountControl{ 7zD- ?%
private static long lastExecuteTime=0;//上次更新时间 * R%.a^R
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 &Hv;<
/** Creates a new instance of CountThread */ AD^X(rW
public CountControl() {} coDjL.u
public synchronized void executeUpdate(){ 4d!S#zx
Connection conn=null; Nd`HB=ShJ
PreparedStatement ps=null; R0%?:!
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try{ $`|5/,M%QN
conn = DBUtils.getConnection(); -#Np7/
conn.setAutoCommit(false); I(pb-oY3!I
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); FbveI4
for(int i=0;i<CountCache.list.size();i++){ /H')~!Yz
CountBean cb=(CountBean)CountCache.list.getFirst(); 2Ok?@ZdjA{
CountCache.list.removeFirst(); mc?';dEG
ps.setInt(1, cb.getCountId()); #c-b}.R
ps.executeUpdate();⑴ 0pD
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//ps.addBatch();⑵ 1h2H1gy5I3
} Qh\YR\O
//int [] counts = ps.executeBatch();⑶ m$,,YKhh
conn.commit(); Rab#7Q16Q8
}catch(Exception e){ '9qn*H`'
e.printStackTrace(); 2G?$X?
} finally{ 1t+%Gv^sK
try{ tJ"az=?
if(ps!=null) { XdpF&B&K7Q
ps.clearParameters(); [4p=X=B
ps.close(); (Akd8}nf~
ps=null; `)6>nPr7P
} zLP],wB
}catch(SQLException e){} 80Ag
DBUtils.closeConnection(conn); \/!ZA[D|E\
} <yZP|_
} 2B^~/T<\
public long getLast(){ qU#$2
return lastExecuteTime; G*B$%?n
} GR<c=
public void run(){ c<?[d!vI
long now = System.currentTimeMillis(); 6*Zj]is
if ((now - lastExecuteTime) > executeSep) { ! a o6e
//System.out.print("lastExecuteTime:"+lastExecuteTime); ~ FGe~
//System.out.print(" now:"+now+"\n"); D}w<84qX
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); n12UBvc}%
lastExecuteTime=now; a5a1'IVq
executeUpdate(); [B,'=,Hbs
} %swR:Bv
else{ <s_=-"
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ?4 qkDtm
} BEWro|]cM
} l7z6i*R
} atyu/+U'}
//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 1Y#HcW&
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类写好了,下面是在JSP中如下调用。 Z'Q*L?E8M
%*kLEA*v
<% "}@i+oS
CountBean cb=new CountBean(); Lj8)'[K"
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); n+HsQ]z.
CountCache.add(cb); 3y ryeS
out.print(CountCache.list.size()+"<br>"); J*j5#V];
CountControl c=new CountControl(); =h|wwQE
c.run(); K#!X><B'
out.print(CountCache.list.size()+"<br>"); DR@1z9 a
%>