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: #V$h?`qhwr
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CountBean.java &V(;zy4(R
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/* SVn $!t
* CountData.java hA=}R.gi
* `lcQ
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* Created on 2007年1月1日, 下午4:44 cH:9@> '$a
* mW=9WV
* To change this template, choose Tools | Options and locate the template under mFrDV,V
* the Source Creation and Management node. Right-click the template and choose "t)$4gERK
* Open. You can then make changes to the template in the Source Editor. Y !%2vOt
*/ -, uT8'
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package com.tot.count; ><xJQeW
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/** Oy_%U*
* 9]%2Yb8SC
* @author 7{lWg x
*/ NjbIt=y
public class CountBean { h?Lp9VF
private String countType; i`}!<{k
int countId; 3Z}v%=5
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/** Creates a new instance of CountData */ d7G
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public CountBean() {} YSbeCyv
public void setCountType(String countTypes){ ]E$bK
this.countType=countTypes; w0X})&,{`m
} _>J`e7j+
public void setCountId(int countIds){ ^'p!#\T;H
this.countId=countIds; a+^,EY
} ws<pBC,m
public String getCountType(){ }g&
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return countType; 8Z CR9%
} Rn*@)5
public int getCountId(){ M5:j)oW
return countId; ${e5Ka
} !l5@L\
} i9Eh1A3Y
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CountCache.java /r8sL)D+
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/* OX7a72z
* CountCache.java <v!jS=T
* 5+2qx)FZ
* Created on 2007年1月1日, 下午5:01 CfT(a!;Eox
* %~:@}C%A
* To change this template, choose Tools | Options and locate the template under #^tnRfS"
* the Source Creation and Management node. Right-click the template and choose A
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* Open. You can then make changes to the template in the Source Editor. ,Jx.Kj.,
*/ mV0u:ws
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package com.tot.count;
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import java.util.*; y@SI )&D
/** p|em_!H"SH
* TR%8O;
* @author kQp*+ras
*/ T 0qM"
public class CountCache { CzIs_/
public static LinkedList list=new LinkedList(); Y$#6%`*#>n
/** Creates a new instance of CountCache */ qDcoccEf
public CountCache() {} 1\)C;c,
public static void add(CountBean cb){ >S8
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if(cb!=null){ Fkg%_v$
list.add(cb); 4aKppj
} wD/jN:
} 1SH]$V4C
} sm{/S*3
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CountControl.java q VavP6I
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/* jxZf,]>T
* CountThread.java EnmMFxu<
* f\r"7j
* Created on 2007年1月1日, 下午4:57 BSy{"K*M
* e}n(mq
* To change this template, choose Tools | Options and locate the template under xLms|jS
* the Source Creation and Management node. Right-click the template and choose i(ZzE
* Open. You can then make changes to the template in the Source Editor. 2`rJ r
*/ vY"I
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package com.tot.count; 138v{Z
import tot.db.DBUtils; +p&zM3:9w
import java.sql.*; a^\F9^j
/** @
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* !E|R3eX_
* @author 8C[eHC*r
*/ "a(e2H2&T4
public class CountControl{ Y]^*mc0fE
private static long lastExecuteTime=0;//上次更新时间 C,%Dp0
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 cP4C<UG
/** Creates a new instance of CountThread */ |onLJY7)
public CountControl() {} Vk2%yw>
public synchronized void executeUpdate(){ .wUnN8crQ
Connection conn=null; Ups0Xg&{
PreparedStatement ps=null; e
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try{ wp'[AR}
conn = DBUtils.getConnection(); b4EUrSL
conn.setAutoCommit(false); yMzy!b Ky
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Y^C(<N$
for(int i=0;i<CountCache.list.size();i++){ SL/'UoYm<
CountBean cb=(CountBean)CountCache.list.getFirst(); wWSw0 H/
CountCache.list.removeFirst(); _zzT[}
ps.setInt(1, cb.getCountId()); j+S&5C/{
ps.executeUpdate();⑴ [ w-Tf&
//ps.addBatch();⑵ ^uphpABpD
} Dx=RLiU9
//int [] counts = ps.executeBatch();⑶ y+= s/c
conn.commit(); TXT<6(
}catch(Exception e){ 9UV}`UM3V
e.printStackTrace(); 1<m.Q*
} finally{ P[$idRS&
try{ 9V~hz (^
if(ps!=null) { 8N$Xq\Da+>
ps.clearParameters(); @P>>:002/
ps.close(); eu8a<
ps=null; W#kyD)(F
} ^CM@VmPp
}catch(SQLException e){} L]Xx-S
DBUtils.closeConnection(conn); O2yD{i#l*#
} b|G~0[g
} DZLEx{cm
public long getLast(){ +fKV/tSWi
return lastExecuteTime; TKbfZw
} |/c-~|%
public void run(){ 6i~<,;Cn
long now = System.currentTimeMillis(); m6H+4@Z-;(
if ((now - lastExecuteTime) > executeSep) { ;j[gE
//System.out.print("lastExecuteTime:"+lastExecuteTime); &~x |w6M]J
//System.out.print(" now:"+now+"\n"); `Fe/=]<$
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); "vkM*HP
lastExecuteTime=now; ;%i-:<ac
executeUpdate(); 9eE
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} A[`c+&
else{ QNv5CQ&
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ftRdK>a
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} BeD>y@ it
} s&CK
} 7:=(yBG
//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 :/Z1$xS
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类写好了,下面是在JSP中如下调用。 %s5(''a.
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<% C43I(.2g
CountBean cb=new CountBean(); 8/y8tMm]
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); paYS<8In
CountCache.add(cb); .b!HEi<F
out.print(CountCache.list.size()+"<br>"); &|Rww\oJ
CountControl c=new CountControl(); a3z_o)"
c.run(); 9"/=D9o9
out.print(CountCache.list.size()+"<br>"); _{}^]ZB
%>