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: E]8uj8K3]
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CountBean.java _Rb2jq(&0
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/* |AacV
* CountData.java 7p hf
* .heU
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* Created on 2007年1月1日, 下午4:44 REgM
* j>e RV ol
* To change this template, choose Tools | Options and locate the template under g1?9ge1
* the Source Creation and Management node. Right-click the template and choose SB08-G2
* Open. You can then make changes to the template in the Source Editor. o<iU;15
*/ 1<fW .Q)
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package com.tot.count; G@`ZDn
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/** &PH:J*?C}
* DRR)mQBb
* @author !zm;C@}ln
*/ 4;W{#jk
public class CountBean { M|j=J{r
private String countType; Cl9rJ oT
int countId; ^-Ygh[x
/** Creates a new instance of CountData */ ~ +>ehU
public CountBean() {} P[-do
public void setCountType(String countTypes){ ?pfr^
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this.countType=countTypes; _9t1aP5
} XXhN;-p
public void setCountId(int countIds){ W8$0y2
this.countId=countIds; 122s7A
} JBLUX,
public String getCountType(){ <&3aP}
return countType; ez ! W0
} Zhv%mUj~
public int getCountId(){ -|^)8
return countId; :F@Uq<~(
} "&/2@
} g`Cv[Pq?at
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CountCache.java \y:48zd
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/* ^e <E/j{~
* CountCache.java L -:@Om!
* m2"e ]I
* Created on 2007年1月1日, 下午5:01 [>r0
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* L@/IyQ[H1
* To change this template, choose Tools | Options and locate the template under 5-$D<}Z
* the Source Creation and Management node. Right-click the template and choose Z)$@1Q4P?1
* Open. You can then make changes to the template in the Source Editor. "g #%d
*/ nw%9Qw
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package com.tot.count; OA=~i/n~
import java.util.*; (xN1?qXB.
/** 2_)UHTwsK
* *Cf!p\7!
* @author T@i*
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*/ NN=^4Xpc:
public class CountCache { 23i2yT
public static LinkedList list=new LinkedList(); G`kz 0Vk
/** Creates a new instance of CountCache */ GF8wKx#J
public CountCache() {} __Ksn^I
public static void add(CountBean cb){ Hnk&2bY
if(cb!=null){ aA52Li
list.add(cb); i>,AnkI&
} ~gW^9nWYU
} ~Ck OiWC0
} {ri={p]l
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CountControl.java tE{M
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/* d6'G
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* CountThread.java pvUV5^B(M
* %b<W]HwA
* Created on 2007年1月1日, 下午4:57 _p%n%Oce
* pvsa?z;rP
* To change this template, choose Tools | Options and locate the template under 0"%dPKi
* the Source Creation and Management node. Right-click the template and choose ;aWk-
* Open. You can then make changes to the template in the Source Editor. ;h+~xxu=X
*/ }.E^_`
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package com.tot.count; dH;2OWM
import tot.db.DBUtils; AQ@)'
import java.sql.*; rvy%8%e?
/** qf\W,SM
* ?.%dQ0
* @author r>FwJm!
*/ ]#^v754X^T
public class CountControl{ ]S[/a
private static long lastExecuteTime=0;//上次更新时间 .4[3r[
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 9l&q}
/** Creates a new instance of CountThread */ gee~>l
public CountControl() {} :,aY|2si
public synchronized void executeUpdate(){ Sk>=C0f:
Connection conn=null; !|xB>d
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PreparedStatement ps=null; t~j6w sx;
try{ `3i>e<m~
conn = DBUtils.getConnection(); <MkvlLu((o
conn.setAutoCommit(false); ~Ay)kv;
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); @}g3\xLiK
for(int i=0;i<CountCache.list.size();i++){ }URdoTOvb
CountBean cb=(CountBean)CountCache.list.getFirst(); EG3,TuDH8
CountCache.list.removeFirst(); -wiQd@X
ps.setInt(1, cb.getCountId()); ;[R6rVHe{
ps.executeUpdate();⑴ J|f29B-c
//ps.addBatch();⑵ o>,r<
} > B@ c74
//int [] counts = ps.executeBatch();⑶ yiC7)=
conn.commit(); s.
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}catch(Exception e){ =X7kADRq
e.printStackTrace(); %eg +.
} finally{ A8vd@0
try{ FUI*nkZY
if(ps!=null) { U?:P7YWy
ps.clearParameters(); ^ZQMRNP{r
ps.close(); *}lLV.+A
ps=null; [QgP6f]=
} }#H,oy;Dz
}catch(SQLException e){} !Z:XSF[T
DBUtils.closeConnection(conn); ^wd@mWxx
} Lo!hyQ)
} zT78FliY6
public long getLast(){ }u
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return lastExecuteTime; =;uMrb4
} 7\2I>W
public void run(){ }-Mg&~e`
long now = System.currentTimeMillis(); d2#NRqgQ
if ((now - lastExecuteTime) > executeSep) { }^Q:Q\
//System.out.print("lastExecuteTime:"+lastExecuteTime); Mt-r`W3 q
//System.out.print(" now:"+now+"\n"); 1l#46?]~
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 8A3/@Z;0S
lastExecuteTime=now; #\lvzMjCC
executeUpdate(); F5
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} ylZQwICk
else{ >pfeP"[(3
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); jjj<B'zt
} ;(/go\m
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} N, Ma\D+^t
} {V
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//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 f_S$CFa@
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类写好了,下面是在JSP中如下调用。 r9_ ON|
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<% 8eS(gKD
CountBean cb=new CountBean(); /o;L,mcx*
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); W"vLCHTh
CountCache.add(cb); tjx8UgSi
out.print(CountCache.list.size()+"<br>"); G9Uc
}z
CountControl c=new CountControl(); Z\CvaX
c.run(); Ie.
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out.print(CountCache.list.size()+"<br>"); .u&xo{$'dS
%>