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: {;n?c$r
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CountBean.java Gxi;h=J2)>
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/* R>/M>*C
* CountData.java 7/PHg)&
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* Created on 2007年1月1日, 下午4:44 '8*gJ7]
* $#]?\psf
* To change this template, choose Tools | Options and locate the template under Qc[[@=S%
* the Source Creation and Management node. Right-click the template and choose Yo|
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* Open. You can then make changes to the template in the Source Editor.
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*/ u8+<uWB
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package com.tot.count; v
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/** }2`S@Rq.WW
* 0a8nBo7A-X
* @author ^b-H
*/ z6Su`
public class CountBean { )6bxP&k
private String countType; sn5N9=\+T
int countId; _N/]&|.. !
/** Creates a new instance of CountData */ Xuh_bW&zF
public CountBean() {} :Jhx4/10
public void setCountType(String countTypes){ k`oXo%
this.countType=countTypes; B|:{.U@ne
} i$"FUC~'
public void setCountId(int countIds){ &\<RVE
this.countId=countIds; B
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} o<Y|N
public String getCountType(){ +bdkqdB9
return countType; )Bb :tz+
} VZAdc*X
public int getCountId(){ OUI}jJw+
return countId; "5{Yn!-:
} *9PS2*n
} hXz"}X n
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CountCache.java $XyGCn
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/* B{)Du
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* CountCache.java ,Yi =s;E
* Vg:P@6s
* Created on 2007年1月1日, 下午5:01 aj(M{gFq~
* Dcus-,u~
* To change this template, choose Tools | Options and locate the template under Y] P}7GZ
* the Source Creation and Management node. Right-click the template and choose /3KEX{'@U
* Open. You can then make changes to the template in the Source Editor. yA%[u.{
*/ ~@'|R%jJ
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package com.tot.count; De>pIN;B>
import java.util.*; N..9N$+(
/** ~Rv U+D
* ya:H{#%6
* @author l'
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*/ Nz!AR$
public class CountCache { _F@FcFG1Z*
public static LinkedList list=new LinkedList(); ,x{5,K.yWq
/** Creates a new instance of CountCache */ F6%rH$aS
public CountCache() {} ;A-Ef
public static void add(CountBean cb){ _^P>@
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if(cb!=null){ 5+ fS$Q
list.add(cb); Cs]xs9
} B5I(ai7<M
} ;H:qDBH
} QtN 0|q{af
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CountControl.java A%Bz52yg
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/* =WO{h48]
* CountThread.java xHD!8B)
* 3J(STIxg
* Created on 2007年1月1日, 下午4:57 kY_UY~E
* OVj,qL)
* To change this template, choose Tools | Options and locate the template under 9 z3Iwl
* the Source Creation and Management node. Right-click the template and choose j<l>+.,
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* Open. You can then make changes to the template in the Source Editor. e;!<3b
*/ NoKYHN^*w
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package com.tot.count; =A!I-@]q<
import tot.db.DBUtils; 57[O)5u.+
import java.sql.*; .Bi7~*N
/** m|f|u3'z$
* (>;~((2
* @author \H" (*["&
*/ |#-Oz#Eg'
public class CountControl{ UI!EIZ*~
private static long lastExecuteTime=0;//上次更新时间 Q'A->I<;_s
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 K} ;uH,
/** Creates a new instance of CountThread */ ait/|a
public CountControl() {} l;|1C[V
public synchronized void executeUpdate(){ eGguq~s`
Connection conn=null; JT_#>',
PreparedStatement ps=null; P AKh v.7
try{ }>0UaK
conn = DBUtils.getConnection(); \lY26'
conn.setAutoCommit(false); w6wXe_N+M
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); OKf/[hyu
for(int i=0;i<CountCache.list.size();i++){ ol:_2G2xQ
CountBean cb=(CountBean)CountCache.list.getFirst(); r;Dl
CountCache.list.removeFirst(); ;- cq#8S
ps.setInt(1, cb.getCountId()); wwpvmb
ps.executeUpdate();⑴ Q0 ^?jh
//ps.addBatch();⑵ A$5!]+
} -7pZRnv
//int [] counts = ps.executeBatch();⑶ l[.pI];T
conn.commit(); !MGQ+bD6
}catch(Exception e){ F`38sq
e.printStackTrace(); }NYsKu_cM
} finally{ M~"K@g=Wr
try{ `q5*VqIhs
if(ps!=null) { HX=`kkX
ps.clearParameters(); _C*}14
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ps.close(); ,>~92
ps=null; a{-}8f6
} |bBYJ
}catch(SQLException e){}
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DBUtils.closeConnection(conn); ]0O pd9
} /Wj9Stj5
} G4=v2_]
public long getLast(){ rsc8lSjH
return lastExecuteTime; )?_c7
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} W}Z|v
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public void run(){ s+(8KYTs`
long now = System.currentTimeMillis(); S&QZ"4jq
if ((now - lastExecuteTime) > executeSep) { goxgJOiB
//System.out.print("lastExecuteTime:"+lastExecuteTime); U|y+k`
//System.out.print(" now:"+now+"\n"); )P,jpE8
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); )D#*Q~
lastExecuteTime=now; YL{LdM-xM
executeUpdate(); '7E?|B0],
} @,s[l1P
else{ | 9(uiWf
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); c5t?S@b
} "0]i4d1l
} V=
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} Uq[NOJC
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 H>W A?4
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类写好了,下面是在JSP中如下调用。
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<% g@S"!9[;U
CountBean cb=new CountBean(); l9SbuT$U
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); hx:x5L>
CountCache.add(cb); ^c-1wV`/
out.print(CountCache.list.size()+"<br>"); v4 c_UFEh<
CountControl c=new CountControl();
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c.run(); ~A6QX8a
out.print(CountCache.list.size()+"<br>"); M~wJe@bc
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