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: eI$V2
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CountBean.java )7*'r@
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/* B$2b=\
* CountData.java g{DehBM
* 6
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* Created on 2007年1月1日, 下午4:44 o`c+eMwr(
* ~Tt@v`}
* To change this template, choose Tools | Options and locate the template under ,5$G0
* the Source Creation and Management node. Right-click the template and choose Fy{yg]O"
* Open. You can then make changes to the template in the Source Editor. rByth,|
*/ vIJ5iLF
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package com.tot.count; [<53_2]~
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/** YAc:QVT87
* <ZSXOh,'
* @author `w
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*/ HMF2sc$N
public class CountBean { M]PZwW8
private String countType; @~$d4K
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int countId; >}* W$i
/** Creates a new instance of CountData */ O(W"QY
public CountBean() {} Nb$0pc1J<
public void setCountType(String countTypes){ UAF$bR
this.countType=countTypes; #S?^?3d
} ;F258/J
public void setCountId(int countIds){ I9Ohz!RQ
this.countId=countIds; IVh5SS
} /GGyM]k3
public String getCountType(){ QWOPCoUet
return countType; <5E'`T
} Vbv^@Kp
public int getCountId(){ 89:nF#
return countId; cIw X sx
} 0E26J@jcZ7
} ="$w8iRU
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CountCache.java )<V!lsUx'-
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/* yb',nGl~
* CountCache.java h7+"*fN
* h&j2mv(
* Created on 2007年1月1日, 下午5:01 DD=X{{;D\"
* (
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* To change this template, choose Tools | Options and locate the template under 90}vFoy
* the Source Creation and Management node. Right-click the template and choose s@{82}f~
* Open. You can then make changes to the template in the Source Editor. AF#:*<Ev
*/ ysOf=~1
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package com.tot.count; 4N,[Gs<7
import java.util.*; *Vl#]81~
/** KhWy
* 1TTS@\
* @author +1T>Ob;hk
*/ G K~A,Miqk
public class CountCache { LKvX~68
public static LinkedList list=new LinkedList(); @LI;q
/** Creates a new instance of CountCache */ m[=SCH-;
public CountCache() {} @;eH~3P
public static void add(CountBean cb){ 6 EqN>.
if(cb!=null){ 3yRvs;nWS
list.add(cb); F\N0<o
} 7#C$}1XJ1
} \L(jNN0_R
} }SWfP5D@
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CountControl.java bQ>wyA+G&E
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/* Mrk3r/
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* CountThread.java [l^XqD D4
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* Created on 2007年1月1日, 下午4:57 !LH;K
* lx2#C9L_
* To change this template, choose Tools | Options and locate the template under /4Wf\
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* the Source Creation and Management node. Right-click the template and choose $EY[CA
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* Open. You can then make changes to the template in the Source Editor. Xi"9y @
*/ &qWg$_Yh
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package com.tot.count; p|-> z
import tot.db.DBUtils; 6kp)'wz`
import java.sql.*; A~Sc ] M
/** +>C26Q
* Y[L,rc/j
* @author |5(un#
*/ o+hp#e
public class CountControl{ !X7z y9
private static long lastExecuteTime=0;//上次更新时间 O83J[YuzjN
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 K7C
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/** Creates a new instance of CountThread */ k+{~#@
public CountControl() {} -I{op
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public synchronized void executeUpdate(){ JYNnzgd
Connection conn=null; #tZ!D^GQHq
PreparedStatement ps=null; 6%p6BK6
try{ CL2zZk{u_
conn = DBUtils.getConnection(); ?x",VA
conn.setAutoCommit(false); BywEoS
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); G h+;Vrx
for(int i=0;i<CountCache.list.size();i++){ ?M4ig_
CountBean cb=(CountBean)CountCache.list.getFirst(); UZt3Ua&J
CountCache.list.removeFirst(); &c-V
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ps.setInt(1, cb.getCountId()); vVtkB$]L
ps.executeUpdate();⑴ WrwbLl E
//ps.addBatch();⑵ mIf)=RW
} BsXF'x<U*
//int [] counts = ps.executeBatch();⑶ P4"BX*x
conn.commit(); ij]~n
}catch(Exception e){ 7|=SZ+g
e.printStackTrace(); fV4eGIR&
} finally{ vULDKJNHX
try{ xKL(:ePS
if(ps!=null) { =55)|$hgD
ps.clearParameters(); I*U7YqDC9
ps.close(); !N+{X\+
ps=null; vrmMEWPV
} JUw|nUnl?
}catch(SQLException e){} 0*]0#2Z
DBUtils.closeConnection(conn); prO&"t
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} )Mq4p'*A[
}
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public long getLast(){ X_-/j.
return lastExecuteTime; IrRy1][Qr
} "T /$K
public void run(){ y+B iaD!U
long now = System.currentTimeMillis(); 9*j"@Rm
if ((now - lastExecuteTime) > executeSep) { )X#$G?|Hn
//System.out.print("lastExecuteTime:"+lastExecuteTime); uq6>K/~D
//System.out.print(" now:"+now+"\n"); '`}D+IQ(j
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); sifjmNP
lastExecuteTime=now; &56\@t^
executeUpdate(); fR;[??NH
} :Hitx
else{ xs6!NY
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); -d!84_d9
} 6@0?~
} IH*G7;
} te;bn4~
//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 clqFV
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类写好了,下面是在JSP中如下调用。 i|H^&$|
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<% 'O ~_g5kC
CountBean cb=new CountBean(); De$Ic"Z9L
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); MIr[_
CountCache.add(cb); Xl$r720ZJr
out.print(CountCache.list.size()+"<br>"); E\4ZUGy0
CountControl c=new CountControl(); uuHs)
c.run();
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out.print(CountCache.list.size()+"<br>"); Q.4+"JoG
%>