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: ["M>
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CountBean.java m0"\3@kB
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/* "=(;l3-o
* CountData.java :I('xVNPz
* /z5lxS@#
* Created on 2007年1月1日, 下午4:44 #V6
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* m5pVt4
* To change this template, choose Tools | Options and locate the template under }}_uN-m
* the Source Creation and Management node. Right-click the template and choose *PEuaRDN
* Open. You can then make changes to the template in the Source Editor. pYG,5+g
*/ A] 9JbNV
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package com.tot.count; j1<1D@UO
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/** B>ZPn6?y
* A&F4;>dms
* @author q@9i3*q;
*/ mmL~`i/
public class CountBean { H~i],WD
private String countType; 81cmG`G7
int countId; q1Sm#_7
/** Creates a new instance of CountData */ }D+8K
public CountBean() {} )mdNvb[*n
public void setCountType(String countTypes){ 7
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this.countType=countTypes; `1@[uWl
} W<VHv"?V
public void setCountId(int countIds){ !&lPdEc@T
this.countId=countIds; B6\VxSX4{
} (Y)h+}n5N
public String getCountType(){ ]Qr8 wa>Z
return countType; ;l ()3;
} oDUMoX%4s
public int getCountId(){ \T9UbkR
return countId; [{F7Pc
} !@{[I:5
} S$52KOo
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CountCache.java ?8@*q6~8
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/* dA/o4co
* CountCache.java 2H[aY%1T
* =7fh1XnW
* Created on 2007年1月1日, 下午5:01 ]ECZU
* e0HP~&BRs
* To change this template, choose Tools | Options and locate the template under !d.>r
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* the Source Creation and Management node. Right-click the template and choose !^fR8Tp9
* Open. You can then make changes to the template in the Source Editor. sVd_O[
*/ ; ZV^e
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package com.tot.count; acY[?L_6J
import java.util.*; ;/ KF3
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/** 2TEeP7
* K)&XQ`&
* @author "n }fEVJ,
*/ Q+(:n)G_6E
public class CountCache { 2bnIT>(
public static LinkedList list=new LinkedList(); 9Fx z!-9m
/** Creates a new instance of CountCache */ hX%v`8
public CountCache() {} T zYgH
public static void add(CountBean cb){ NB5B$q_'#
if(cb!=null){ -_DiD^UcXn
list.add(cb); o%PoSZZ
} Z4ov
} BJxmW's/
} &W+G{W{3
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CountControl.java hX| UE
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/* */dh_P<Yj
* CountThread.java "Vp:z V<S
* Y~hd<8 ~
* Created on 2007年1月1日, 下午4:57 \w[ZY$/
* Z?c=t-yqp
* To change this template, choose Tools | Options and locate the template under X1[R*a/p
* the Source Creation and Management node. Right-click the template and choose b%f2"e0g
* Open. You can then make changes to the template in the Source Editor. 1=5'R/k
*/ zRoEx1
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package com.tot.count; GnrW{o
import tot.db.DBUtils; zw0 r
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import java.sql.*; }_ :#fE
/** =tRe3o0(
* {R!TUQ5
* @author 8tRhV2
*/ 5uJP)S?
public class CountControl{ eKpxskbhZ
private static long lastExecuteTime=0;//上次更新时间 #u5;utY:F
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 S%s|P=u
/** Creates a new instance of CountThread */ "jJdUFN
public CountControl() {} ]AA*f_!
public synchronized void executeUpdate(){ r]EZ)qp^@
Connection conn=null; Ldj^O9p(
PreparedStatement ps=null; Xa%&.&V
try{ $_7d! S"
conn = DBUtils.getConnection(); r]//Q6|S
conn.setAutoCommit(false); %%,hR'+|
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); '`~(Fkj
for(int i=0;i<CountCache.list.size();i++){ %3#I:>si
CountBean cb=(CountBean)CountCache.list.getFirst(); LOUKURe E
CountCache.list.removeFirst(); i
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ps.setInt(1, cb.getCountId()); -5,y
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ps.executeUpdate();⑴ ="w8U'
//ps.addBatch();⑵ }V#9tWW
} h:Mn$VR,
//int [] counts = ps.executeBatch();⑶ 2N8sq(LK{
conn.commit(); ^@LhUs>3
}catch(Exception e){ V?V)&y] 4
e.printStackTrace(); ~v(M6dz~vk
} finally{ 3g#=sd!0O@
try{ IfmIX+t?
if(ps!=null) { 9Bvn>+_K
ps.clearParameters(); ?]:EmP
ps.close(); g yH7((#i
ps=null;
;/^]|
} -anFt+f-
}catch(SQLException e){} y7IbE
DBUtils.closeConnection(conn); (zro7gKked
} Y=Ar3O*F
} nh&J3b}B!
public long getLast(){ -k[tFBlw
return lastExecuteTime; [FV=@NI
} ':2*+
public void run(){ $h]Y<&('G
long now = System.currentTimeMillis(); uZ`d&CEh
if ((now - lastExecuteTime) > executeSep) { xBE
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//System.out.print("lastExecuteTime:"+lastExecuteTime); ]^6y NtLK
//System.out.print(" now:"+now+"\n"); ~)m t &
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); G5nj,$F+
lastExecuteTime=now; cwWSNm|
executeUpdate(); 'oHOFH9:{b
} voej ~z+
else{ CWe>jlUQ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); L[D/#0qp
} Rr;LV<q+
} q~'
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} Jyz$&jqyr'
//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 EBDC '^
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类写好了,下面是在JSP中如下调用。 uM#U!
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<% gC_s\WU
CountBean cb=new CountBean(); )<x;ra^
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); X?v^>mA
CountCache.add(cb); 5)>ZO)F&
out.print(CountCache.list.size()+"<br>"); qnk,E-
CountControl c=new CountControl(); o )nT
c.run(); wp]7Lx?F
out.print(CountCache.list.size()+"<br>"); D_19sN@0m
%>