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: \{o<-S;h
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CountBean.java hh-sm8
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/* &E-q(3-
* CountData.java Na+3aM%%
* (^~~&/U_U$
* Created on 2007年1月1日, 下午4:44 '.7ER
* mwF{z.t"
* To change this template, choose Tools | Options and locate the template under IG!(q%Gf
* the Source Creation and Management node. Right-click the template and choose iVb7>d9}
* Open. You can then make changes to the template in the Source Editor. uFfk!
*/ zTw<9 Nf
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package com.tot.count; QF$s([
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/** UDlM?r:f
*
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* @author N <M6~
*/ H^jcWwy:
public class CountBean { ,S&p\(r.
private String countType; D*g
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int countId; Gf-GDy\{
/** Creates a new instance of CountData */ 7H?lR~w
public CountBean() {} XM`&/)
public void setCountType(String countTypes){ ZSLvr-,D
this.countType=countTypes; r>6FJ:Tx
} 7LiyA<
public void setCountId(int countIds){ CxrsP.
this.countId=countIds; x}O J~Yk]
} sl)]yCD|5
public String getCountType(){ D_BdvWSxj
return countType; oKPG0iM:
} UTO$L|K
public int getCountId(){ IB^vEY!`6_
return countId; 4
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} x.'Ys1M
} USKC,&6&}
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CountCache.java ?v&2^d4C*F
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/* N({-&A.N
* CountCache.java /mK]O7O7
* `~h8D9G
* Created on 2007年1月1日, 下午5:01 R+9 hog
* 1+xi1w}3a
* To change this template, choose Tools | Options and locate the template under vg5fMH9ZZ
* the Source Creation and Management node. Right-click the template and choose <m%ZDOMa
* Open. You can then make changes to the template in the Source Editor. %z-n2%
*/ .+~9
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package com.tot.count; <,J O
import java.util.*; Li\b,_C
/** *nwH1FjH
* Lv
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* @author 1{G@'#(
*/ a@#<qf8g
public class CountCache { 3w+ +F@(
public static LinkedList list=new LinkedList(); ONLhQJCb
/** Creates a new instance of CountCache */ BipD8`a
public CountCache() {} 5[P^O6'
public static void add(CountBean cb){ Sy^@v%P'A
if(cb!=null){ v1 f^gde
list.add(cb); ix 5\Y
} 5Trc#i<\
} #,OiZQJC
} jIWX6
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CountControl.java T^Hq 5Oy
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/* +xNq8yS
* CountThread.java hO(A_Bw
* h2
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* Created on 2007年1月1日, 下午4:57 U \jFB*U
* gKRlXVS
* To change this template, choose Tools | Options and locate the template under DOq"=R+
* the Source Creation and Management node. Right-click the template and choose * K0aR!
* Open. You can then make changes to the template in the Source Editor. 3
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*/ ,?!MVN-
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package com.tot.count; 4cDe'9
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import tot.db.DBUtils; +SkfT4*U
import java.sql.*; ;Ehv1{;
/** /=KEM gI?
* 2D"aAI<P
* @author J n'SGR
*/ e)|5P
public class CountControl{ 4K
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private static long lastExecuteTime=0;//上次更新时间 qrcir-+
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 l)Mi?B~N
/** Creates a new instance of CountThread */ i L'j9_w,
public CountControl() {} BKu<p<
public synchronized void executeUpdate(){ =an0PN
Connection conn=null; }zrapL"9X
PreparedStatement ps=null; tQ`|MO&o
try{ ^NO4T
conn = DBUtils.getConnection(); M/YS%1
conn.setAutoCommit(false); "FLiSz%ME
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); c4}|a1R\=
for(int i=0;i<CountCache.list.size();i++){ fj[Kbo 7!h
CountBean cb=(CountBean)CountCache.list.getFirst(); eqqnR.0
CountCache.list.removeFirst(); VBK |*Tl
ps.setInt(1, cb.getCountId()); 18>v\Hi<
ps.executeUpdate();⑴ BxB B](
//ps.addBatch();⑵ mnU8i=v0A
} +(h{3Y|
//int [] counts = ps.executeBatch();⑶ c;88Wb<|W
conn.commit(); =|H.r9-PK6
}catch(Exception e){ WpC9(AX5g
e.printStackTrace(); iK8jX?
} finally{ yn.[-
try{ t<e3EW@>>
if(ps!=null) { vZXdc+2l
ps.clearParameters(); 7hT@,|(j
ps.close(); Fm+V_.H/;
ps=null; }l_8~/9
} ]^<\a=U
}catch(SQLException e){} I 1Yr{(ho
DBUtils.closeConnection(conn); T2|os{U
} ;&MnPFmq
} sk@aOv'*(
public long getLast(){ `)TgGny01
return lastExecuteTime; 9G4os!x)
} -0<ZN(?|
public void run(){ \xmDkWzE
long now = System.currentTimeMillis(); 3=%G{L16-
if ((now - lastExecuteTime) > executeSep) { ^grDP*;W
//System.out.print("lastExecuteTime:"+lastExecuteTime); lLI%J>b@
//System.out.print(" now:"+now+"\n"); rVp^s/A^;
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); }$s QmRR
lastExecuteTime=now; t;_1 /mt
executeUpdate(); 3A\Z]L
} a >k9&
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else{ VOT9cP^6
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ypx`!2Q$
} n2Q?sV;m
} ovaX_d)cU
} ^!x qOp!
//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 )))AxgM
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类写好了,下面是在JSP中如下调用。 k7M{+X6[
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<% SKGnx
CountBean cb=new CountBean(); EF;B)y=
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ?F~0\T,7
CountCache.add(cb); r>G||/Z
out.print(CountCache.list.size()+"<br>"); C#RueDa.
CountControl c=new CountControl(); ^BP4l_rO9
c.run(); %cASk>^i
out.print(CountCache.list.size()+"<br>"); rw75(Lp{
%>