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: FVi7gg.?
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CountBean.java ZboY]1L[j
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/*
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* CountData.java ~yrEB:w`_
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* Created on 2007年1月1日, 下午4:44 xA?(n!{P
* /j}"4_.8
* To change this template, choose Tools | Options and locate the template under >ZX&2 {
* the Source Creation and Management node. Right-click the template and choose _ML`Vh]
* Open. You can then make changes to the template in the Source Editor. @Kl'0>U
*/ jv<C#0E^
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package com.tot.count; )21yD1"6
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/** 5Vq&w`sW
* vz{Z
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* @author =Fu~ 0Wc
*/ m+Um^:\jX
public class CountBean { {`X O3
private String countType; [PRQa[_
int countId; qKL:#ny
/** Creates a new instance of CountData */ R]Iv?)Y
public CountBean() {} $0(~ID
public void setCountType(String countTypes){ ;ty08D/
this.countType=countTypes; CAs8=N#H%
} ONc-jU^
public void setCountId(int countIds){ Qv v~nGq$
this.countId=countIds; gGdt&9z
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} /b
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public String getCountType(){ cN]e{|
return countType; "$@Wy,yp
} 5(+9(
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public int getCountId(){ -FxE!K
return countId; JZc"4qf@OT
} d z-
} RxeyMNd
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CountCache.java 5:"zs
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/* -D?-ctFYj^
* CountCache.java .YYLMI
* :h(r2?=7
* Created on 2007年1月1日, 下午5:01 =zetZJg
* Y1=.46Ezf
* To change this template, choose Tools | Options and locate the template under j B.ZF7q
* the Source Creation and Management node. Right-click the template and choose Oo-%;l`&
* Open. You can then make changes to the template in the Source Editor. L5wrc4
*/ 7QnQ=gu
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package com.tot.count; +?&|p0
import java.util.*; pz
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/** ,.Sd)JB'
* :\Pk>a
* @author nKR=/5a4Y
*/ 6/4?x)l3-
public class CountCache { y?r:`n
public static LinkedList list=new LinkedList(); vc r5
/** Creates a new instance of CountCache */ /a'cP
public CountCache() {} \os iY^
public static void add(CountBean cb){ 5:T)hoF@
if(cb!=null){ MhaoD5*9
list.add(cb); ~WKcO&
} 94Hs.S)
} >U%:Nfo3
} $t1XoL
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CountControl.java -C
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/* a,EApUWw
* CountThread.java L2NO_N
* +^@;J?O
* Created on 2007年1月1日, 下午4:57 cW|M4`
* cD!yd^QE
* To change this template, choose Tools | Options and locate the template under [0lu&ak[&
* the Source Creation and Management node. Right-click the template and choose @/DHfs 4O
* Open. You can then make changes to the template in the Source Editor. Q+r8qnL'
*/ .5ItH^
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package com.tot.count; 0}:wM':G
import tot.db.DBUtils; |K7zN\
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import java.sql.*; 8B|qNf `Yi
/** sy
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* O=A(x m#
* @author %XUV[L}
*/ Y,
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public class CountControl{ 0=,vdT
private static long lastExecuteTime=0;//上次更新时间 AVR=\ qR
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 DXH"`1[-
/** Creates a new instance of CountThread */ #&oL iz=hZ
public CountControl() {}
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public synchronized void executeUpdate(){ CSBk
Connection conn=null; )]W|i9
PreparedStatement ps=null; G\I DgPj`
try{ s/"l ?d
conn = DBUtils.getConnection(); bq}hj Cy
conn.setAutoCommit(false); ^kF-mM=
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); }2 X"
for(int i=0;i<CountCache.list.size();i++){ *pZhwO!D
CountBean cb=(CountBean)CountCache.list.getFirst(); kv)IG$S0
CountCache.list.removeFirst(); LY? `+/
ps.setInt(1, cb.getCountId()); H:x{qS4Si
ps.executeUpdate();⑴ ivi,/~L
//ps.addBatch();⑵ iuxS=3lT"K
} r^jiK\*
//int [] counts = ps.executeBatch();⑶ 9pPohR*#V
conn.commit(); ,[j'OyR
}catch(Exception e){ iW\Q>~0#_
e.printStackTrace(); kzUP
} finally{ REaU=-m-
try{ u\uY q
if(ps!=null) { g6wL\g{29
ps.clearParameters(); 13lJq:bM
ps.close(); Pv>W`/*_,s
ps=null; $QbaPmHW
} zdh&,!] F6
}catch(SQLException e){} _rmTX.'w
DBUtils.closeConnection(conn); mh8{`W &
} VD).UdUn
} DNu^4#r
public long getLast(){ `1Cg)\&[e0
return lastExecuteTime; /3>5ex>PN
} ]'%Z&1 w
public void run(){ iFi6,V*PRt
long now = System.currentTimeMillis(); 2X@|H
if ((now - lastExecuteTime) > executeSep) { Q^_*&},V
//System.out.print("lastExecuteTime:"+lastExecuteTime); QUSyVp{$
//System.out.print(" now:"+now+"\n"); o;#9$j7QP!
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ujt0?DM
lastExecuteTime=now; lls-Nir%
executeUpdate(); ,Zs"r}G^
} Z_tK3kQa@&
else{ #K[UqJ+x
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); |;[%ZE"
} 5VXI/Lw#
} <Y9 L3O`[
} <$8`]e?I
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 js~?y|e8k
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类写好了,下面是在JSP中如下调用。 I<["ko,t@?
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<% y!,Ly_x$@
CountBean cb=new CountBean(); i- v PJg1
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); %( tu<
CountCache.add(cb); 2L!wbeTb;
out.print(CountCache.list.size()+"<br>"); c[h{C!d1
CountControl c=new CountControl(); DviR D[+q"
c.run(); Ns*&;x9
out.print(CountCache.list.size()+"<br>"); aJmSagr69C
%>