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: :!;BOCTYI
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CountBean.java }r3,
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/* RX4O1Z0
* CountData.java ?|Fu^eR%X
* 3!`Pv ?|o
* Created on 2007年1月1日, 下午4:44 5F+5J)h
* cRsLt/Wr
* To change this template, choose Tools | Options and locate the template under Mcj4GjV6:"
* the Source Creation and Management node. Right-click the template and choose L.$9ernVY
* Open. You can then make changes to the template in the Source Editor. (P~Jzp9u
*/ T/p}Us
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package com.tot.count; Za}*6N=?*
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/** X?z5IL;rt
* Yr-a8aSTE5
* @author E D*=8s2
*/ P5* :r3>
public class CountBean { e]!Vxn3
private String countType; \O/" F;
int countId; GBzC<e#
/** Creates a new instance of CountData */ @/l{
public CountBean() {} x=Qy{eIe
public void setCountType(String countTypes){ jy(,^B,]
this.countType=countTypes; xyj)W
} VQU [5C
public void setCountId(int countIds){ i:Pg&474f
this.countId=countIds; NoO>CjeFb
} n{d}]V@
public String getCountType(){ DQP#h5O
return countType; s0H_Y'
} fO[X<|9
public int getCountId(){ Wg[?i C*~
return countId; @^a6^*X>
} ,pa,:k?
} 0aQtJ0e16
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CountCache.java T~cq= i|O
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/* "Ol;0>$
* CountCache.java y$r^UjJEO
* DBAJkBs
* Created on 2007年1月1日, 下午5:01 I{<6GIU+
* J_}&Btb)e
* To change this template, choose Tools | Options and locate the template under
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* the Source Creation and Management node. Right-click the template and choose GC66n1- X
* Open. You can then make changes to the template in the Source Editor. _DMj)enH"
*/ rtvuAFiH
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package com.tot.count; &FHE(7}/#
import java.util.*; '[-gKn
/** ioi0^aM
* %=/Y~ml?
* @author _Ta9rDSP]
*/ I|RN/RVN
public class CountCache { vF;6Y(h>
public static LinkedList list=new LinkedList(); PtO-%I<N
/** Creates a new instance of CountCache */ Xx:0Nt]
public CountCache() {} (6u<w#u
public static void add(CountBean cb){ }!0,(<EsV
if(cb!=null){ 'Vy$d<@s[
list.add(cb); <E$P
} E?y0UD[8J
} KZ ?<&x
} &|%z!x6 f
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CountControl.java \4K8*`$
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/* vnk"0d.
* CountThread.java *Zt)J8C
* }tft@,dIC
* Created on 2007年1月1日, 下午4:57 6]T02;b>/,
* aP8Im1<A
* To change this template, choose Tools | Options and locate the template under 8Qu7x[tK?
* the Source Creation and Management node. Right-click the template and choose 8 PXleAn
* Open. You can then make changes to the template in the Source Editor. &BG^:4b
*/ i.cSD%*
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package com.tot.count; UbC)XiO
import tot.db.DBUtils; "uGJ\
import java.sql.*; BRoi`.b:
/** =!U{vT
* x 9Gm)~
* @author *Ei~2O}
*/ sN-5vYfC*
public class CountControl{ -jC. dz
private static long lastExecuteTime=0;//上次更新时间 SnQ$
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 jt3s;U*
/** Creates a new instance of CountThread */ m\1*/6oV
public CountControl() {} ed{z^!w4
public synchronized void executeUpdate(){ v
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Connection conn=null; JB+pd_>5
PreparedStatement ps=null; )KXLL;]
try{ l,6="5t
conn = DBUtils.getConnection(); U%gP2]t%cs
conn.setAutoCommit(false); ,:>>04O
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ]lz,?izMR
for(int i=0;i<CountCache.list.size();i++){ ,e.y4
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CountBean cb=(CountBean)CountCache.list.getFirst(); Q=e?G300#L
CountCache.list.removeFirst(); c0Q`S"o+
ps.setInt(1, cb.getCountId()); Ao{wd1
ps.executeUpdate();⑴ 1O(fI|gcO
//ps.addBatch();⑵ D3XQ>T [*q
} kdxs{b"t
//int [] counts = ps.executeBatch();⑶ ),M8W15
conn.commit(); y;<jE.7>
}catch(Exception e){ qmxkmO+Qur
e.printStackTrace(); 50_%Tl[
} finally{ %A82{
try{ = @3Qsd
if(ps!=null) { e#_xDR:
ps.clearParameters(); %#7M~RB[
ps.close(); QZh8l-!#5
ps=null; OmU.9PDg-
} CuuHRvU8
}catch(SQLException e){} >{m>&u;Cc
DBUtils.closeConnection(conn); z2"2Xqy<U
} )K5~r>n&
} 3*8#cSQ/6o
public long getLast(){ 0CTI=<;
return lastExecuteTime; r43dnwX
} c!kbHZ<Z
public void run(){ Oh8;YE-%
long now = System.currentTimeMillis(); <Xl G :nmY
if ((now - lastExecuteTime) > executeSep) { D.?KgOZ
//System.out.print("lastExecuteTime:"+lastExecuteTime); ,{E'k+
//System.out.print(" now:"+now+"\n"); -O(.J'=8
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 1%1-j
lastExecuteTime=now; A`OU}'v?L
executeUpdate(); kP[ Y
} "h:xdaIE/p
else{ m4 4aKqw)
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ]^j)4us
} :+[q`
} V2.MZ9
} {a(YV\^y|H
//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 NINyg"g<
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类写好了,下面是在JSP中如下调用。 8.9S91]=
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<% |@d7o]eM|
CountBean cb=new CountBean(); RYvS,hf6z
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); e%UFY-2
CountCache.add(cb); Kq.)5%~>
out.print(CountCache.list.size()+"<br>"); d_]MqH>R\
CountControl c=new CountControl(); q$H'u[KQ06
c.run(); N$_Rzh"9rr
out.print(CountCache.list.size()+"<br>"); (c[|k
%>