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:
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CountBean.java H~vrCi~t"
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/* E@xrn+L>-
* CountData.java &fWC-|
* i^iu#WC
* Created on 2007年1月1日, 下午4:44 4k3pm&
* $oM>?h_=
* To change this template, choose Tools | Options and locate the template under 1L'Q;?&2H,
* the Source Creation and Management node. Right-click the template and choose 3RGmmX"?G
* Open. You can then make changes to the template in the Source Editor. `{h)-Y``
*/ dR< d7
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package com.tot.count; -P|claO0
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/** [xrsa!$
* ^xNzppz`]C
* @author [
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*/ yhbU;qEG9
public class CountBean { 7%? bl
private String countType; FvPWS!H
int countId; N[\J#x!U
/** Creates a new instance of CountData */ czu9a"M>X
public CountBean() {} SpU|Q1Q/h
public void setCountType(String countTypes){ :Z2997@Y
this.countType=countTypes; @#N7M2/
} PWx%~U.8~j
public void setCountId(int countIds){ +a|Q)Ob
this.countId=countIds; |94o P>d
} G rU`;M"
public String getCountType(){ 5psJv|Zo]
return countType; BgUp~zdo
} z_R^C%0k
public int getCountId(){ /@1YlxKF
return countId; 52Lp_M
} %Gyn.9\
} l=l$9H,
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CountCache.java dm=?o
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/* 8UgogNR\
* CountCache.java "]q
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* ^<cJ;u*0
* Created on 2007年1月1日, 下午5:01 o/VT"cT
* Z:N;>.3i
* To change this template, choose Tools | Options and locate the template under aZ_3@I{d`
* the Source Creation and Management node. Right-click the template and choose aN07\
* Open. You can then make changes to the template in the Source Editor. >2pxl(i
*/ -2[4 @
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package com.tot.count; S#8)N`
import java.util.*; D QxuV1
/** 1Hr1Ir<KR
* 7rRI-wZ
* @author f"j9C%'*
*/ ]*mUc`
public class CountCache { p o)lN[v
public static LinkedList list=new LinkedList(); EKF4]
/** Creates a new instance of CountCache */ K/N{F\
public CountCache() {} =:w,wI.
public static void add(CountBean cb){ F_R\
if(cb!=null){ &@CUxK
list.add(cb); wn.6l
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} u*=^>LD
} eCN:
} h~9P34m
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CountControl.java w*/@|r39
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/* .0xk},
* CountThread.java )}N:t:rry
* 8/tB?j
* Created on 2007年1月1日, 下午4:57 *aM7d>nG5
* Zv9JkY=+@
* To change this template, choose Tools | Options and locate the template under 9XDSL[[
* the Source Creation and Management node. Right-click the template and choose x X3I`
* Open. You can then make changes to the template in the Source Editor. Q[NoFZ
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*/ ~>9G\/u j
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package com.tot.count; 9,_~qWw
import tot.db.DBUtils; S g1[p#U
import java.sql.*; SZr c-f_
/** ^ }5KM87
* fu~iF
* @author f9>pMfi:@
*/ yBs-bp"-
public class CountControl{ WLj]EsA.
private static long lastExecuteTime=0;//上次更新时间 [@VzpVhXz
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 G[ #R 1'
/** Creates a new instance of CountThread */ SS`\_@ci
public CountControl() {} )mOM!I7D@
public synchronized void executeUpdate(){ weu+$Kr
Connection conn=null; +8?18@obp
PreparedStatement ps=null; ,qp8Rg|3j
try{ 3]JJCaf
conn = DBUtils.getConnection(); ."BXA8c;A
conn.setAutoCommit(false); juF=ZW%i
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 5&EBUl}
for(int i=0;i<CountCache.list.size();i++){ 3$YbEl@#
CountBean cb=(CountBean)CountCache.list.getFirst(); 0<@['W}G
CountCache.list.removeFirst(); \rUKP""m
ps.setInt(1, cb.getCountId()); 8VQ!&^9!U#
ps.executeUpdate();⑴ 5;/q[oXI
//ps.addBatch();⑵ }2RbX,0l9
} E+XS7':I
//int [] counts = ps.executeBatch();⑶ LB]3-FsU+
conn.commit(); K O\HH
}catch(Exception e){ +l)t5Mg\
e.printStackTrace(); JS m7-p|E
} finally{ 0H4|}+e
try{ e4Ibj/
if(ps!=null) {
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ps.clearParameters(); l\AdL$$Mb
ps.close(); r`Fs"n#^-4
ps=null; z;9D[ME#1
} 9<3}zwJ
}catch(SQLException e){} dg#Pb@7a
DBUtils.closeConnection(conn); C|Gk}
} VV$#<D<)
} j?o6>j
public long getLast(){ W>+`e]z
return lastExecuteTime; :PN%'~}n
} Q~wS2f`)
public void run(){ J`[jub
long now = System.currentTimeMillis();
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if ((now - lastExecuteTime) > executeSep) { =kwz3Wv
//System.out.print("lastExecuteTime:"+lastExecuteTime); l(Hz9
//System.out.print(" now:"+now+"\n"); H"w;~;h
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;Qt/(/
lastExecuteTime=now; ](s5;ta
executeUpdate(); .K4)#oC
} !'#
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else{ sDg1nKw(
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 3p HI+a
} ?nL,Otz
} L58H)V3Pn
} 5p~5-_JX
//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 p JF
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类写好了,下面是在JSP中如下调用。 xqg4b{
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<% Y&,}q_Z:
CountBean cb=new CountBean(); t`hes
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); -lfDoNRhQ
CountCache.add(cb); %4M,f.[e
out.print(CountCache.list.size()+"<br>"); 5
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CountControl c=new CountControl(); x5\D u63
c.run(); a;;
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out.print(CountCache.list.size()+"<br>"); OYWHiXE6]
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