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: &G-!qxe
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CountBean.java Ig
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/* w 47tgPPk
* CountData.java [C'JH//q*t
* h5^Z2:#
* Created on 2007年1月1日, 下午4:44 x U4 +|d
* #~
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* To change this template, choose Tools | Options and locate the template under h-[VH%
* the Source Creation and Management node. Right-click the template and choose Ck)*&
* Open. You can then make changes to the template in the Source Editor. hbY5l}\5
*/ VcXq?f>\
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package com.tot.count; c_4[e5z
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/** GJ_7h_4
* NeE
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* @author U`2e{>'4t
*/ 'ZDp5pCC;
public class CountBean { q!|*oUW
private String countType; f,kZ\Ia'r
int countId; PoxK{Y
/** Creates a new instance of CountData */ \nPEyw,U
public CountBean() {} 6G[4rD&
public void setCountType(String countTypes){ J4fi'
this.countType=countTypes; Utnr5^].2O
} ,F,X
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public void setCountId(int countIds){ t.xxSU5~%
this.countId=countIds; X:vghOt?
} Z{]0jhUyNh
public String getCountType(){ hoK>~:;
return countType; &m-PC(W+
} xc=b
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public int getCountId(){ &L'Dqew,*
return countId; /`wvxKX
} [XEkz#{
} #h`
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CountCache.java ChGYTn`X
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/* 1Q<^8N)pf
* CountCache.java H[,i{dD
* %A1o.{H
* Created on 2007年1月1日, 下午5:01 p@xf^[50k
* xhVO3LW'
* To change this template, choose Tools | Options and locate the template under QdF5Cwf4
* the Source Creation and Management node. Right-click the template and choose ZX9T YN
* Open. You can then make changes to the template in the Source Editor. (l^3Z3zf&
*/ v%+:/m1
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package com.tot.count; 6jE|
import java.util.*; 6e9,PS
/** B-ngn{Yc
* g{OwuAC_
* @author 8']M^|1
*/ hYPl&^
public class CountCache { oM2l-[-
public static LinkedList list=new LinkedList(); \2N!:%k
/** Creates a new instance of CountCache */ V58wU:li
public CountCache() {} >,gg5<F-E
public static void add(CountBean cb){ /uPcXq:L~
if(cb!=null){ A9I{2qW9+Z
list.add(cb); 8@i7pBl@
} ~zCEpU|@N
} =RA /
} x+Ttl4
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CountControl.java 0^I|ut4
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/* {> eXR?s/
* CountThread.java *"?l ]d
* gw#5jW\
* Created on 2007年1月1日, 下午4:57 7Ri46Tkt
* t3*wjQ3
* To change this template, choose Tools | Options and locate the template under wvO|UP H\
* the Source Creation and Management node. Right-click the template and choose /oR0+sH]
* Open. You can then make changes to the template in the Source Editor. {@6=Q 6L
*/ %HGD;_bhI
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package com.tot.count; Oft-w)cYz,
import tot.db.DBUtils; Gw>^[dmt!
import java.sql.*; Y2a5bc P
/** e@Fo^#ImDx
* &+Z,hs9%
* @author R)_%i<nq\
*/ sD{Wxv
public class CountControl{ e<3K;Q
private static long lastExecuteTime=0;//上次更新时间 *W.C7=
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 C7rNV0.Fq
/** Creates a new instance of CountThread */ x'+T/zw
public CountControl() {} nxUJN1b!N
public synchronized void executeUpdate(){ +c(zo4nZ
Connection conn=null; :o|\"3
PreparedStatement ps=null; /qMG=Z
try{ l1T m`7}
conn = DBUtils.getConnection(); 13 =A
conn.setAutoCommit(false); F<n3
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); iP
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for(int i=0;i<CountCache.list.size();i++){ &~8oQC-eF
CountBean cb=(CountBean)CountCache.list.getFirst(); C"6?bg5N
CountCache.list.removeFirst(); zz+$=(T:M
ps.setInt(1, cb.getCountId()); DgUT5t1
ps.executeUpdate();⑴ kDEPs$^
//ps.addBatch();⑵ m_.>C
} ,5i` -OI
//int [] counts = ps.executeBatch();⑶ GGNvu)"
conn.commit(); S)cLW~=z
}catch(Exception e){ _"E%xM*r
e.printStackTrace();
#bUXgn>
} finally{ n,jKmA
try{ .n#@$
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if(ps!=null) { H<VTa? n
ps.clearParameters(); tX5"UQA
ps.close(); W}m)cn3@
ps=null; /M|262%
} tXoWwQD;Y
}catch(SQLException e){} kO,zZF&
DBUtils.closeConnection(conn); @LS@cCC,a
} q"%_tS
} qs1 ?IYD
public long getLast(){ v'U{/ ,x
return lastExecuteTime; C9~52+S
} 4,sJE2"[9
public void run(){ ]Y%Vio
long now = System.currentTimeMillis(); oI=fx Sjd
if ((now - lastExecuteTime) > executeSep) { o^^rJk
//System.out.print("lastExecuteTime:"+lastExecuteTime); /q<__N
//System.out.print(" now:"+now+"\n"); v/](yT
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |bq$xp
lastExecuteTime=now; 19HM])Zw\
executeUpdate(); N9jH\0nG
} !
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else{ u -;_y='m
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); xfpa]Z
} >d,jKlh^.%
} wCr(D>iM
} !D@ZYK;
//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 b:Wm8pp?
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类写好了,下面是在JSP中如下调用。 \!k1a^ZP
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<% 23c 8
CountBean cb=new CountBean(); - db_E#
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); /JHc! D
CountCache.add(cb); yUZb#%n
out.print(CountCache.list.size()+"<br>"); %+j8["VEC
CountControl c=new CountControl(); luo
c.run(); 6kNrYom
out.print(CountCache.list.size()+"<br>"); L;*ljZ^c
%>