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: V3K
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CountBean.java fLAOA9
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/* Q&^ti)vB
* CountData.java AM*V4}s*9k
* e?3 S0}
* Created on 2007年1月1日, 下午4:44 UyBI;k^]
* =:mD)oX*
* To change this template, choose Tools | Options and locate the template under z#GZvB/z)
* the Source Creation and Management node. Right-click the template and choose cF3V{b|bU
* Open. You can then make changes to the template in the Source Editor. n
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*/ yb56nd
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package com.tot.count; ?8fa/e
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/** >%x7-->IB
* f{AbCi
* @author R
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*/ 3|-)]^1O
public class CountBean { :84fd\It4
private String countType; kJq8"Klg
int countId; xq-R5(k
/** Creates a new instance of CountData */ ]6Kx0mW
public CountBean() {} A#RA;Dt:
public void setCountType(String countTypes){ i&$L$zf,
this.countType=countTypes; Ey A}
} :o?On/
public void setCountId(int countIds){ (eS4$$g
this.countId=countIds; 03L+[F&"?
} &]3_ .C
public String getCountType(){ (e6JI]tz{
return countType; g"c\ouSY
} d4t%/ Uh
public int getCountId(){ v#{Sx>lO
return countId; vzM8U>M
} [U.3rcT"N
} XT>
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CountCache.java ~cQ./G4
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/* *cz nokq6
* CountCache.java W0J d2 *]
* /J )MW{;O
* Created on 2007年1月1日, 下午5:01 =v]\{.
* l8 k@.<nCO
* To change this template, choose Tools | Options and locate the template under o8;>E>;
* the Source Creation and Management node. Right-click the template and choose A-x; ai]
* Open. You can then make changes to the template in the Source Editor. {z>fe
}
*/ C?m2R(RF
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package com.tot.count; L|pMq!@J
import java.util.*; _ dEc? R}
/** f]Z%,'1^
* 1Kszpt(Ld
* @author >uT,Z,7O
*/ Cl#PYB{1Y
public class CountCache { ~(bY-6z
public static LinkedList list=new LinkedList(); +A%|.;
/** Creates a new instance of CountCache */ 7.mY@
public CountCache() {} Ro3C(aRx
public static void add(CountBean cb){ F|pM$Kd`
if(cb!=null){ E#}OIZ\S
list.add(cb); z#9Tg"8]
} 3'tcEFkH
} v6=pV4k9
} Pt< JF
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CountControl.java G#yv$LY#
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/* S;@nPzhc
* CountThread.java -wn,7;
* w]L^)_'Th
* Created on 2007年1月1日, 下午4:57 ayF+2(vch)
* wT\JA4
* To change this template, choose Tools | Options and locate the template under D2}N6i
* the Source Creation and Management node. Right-click the template and choose DR]=\HQ
* Open. You can then make changes to the template in the Source Editor. y
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*/
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package com.tot.count; by}C;eN
import tot.db.DBUtils; %M)LC>c
import java.sql.*; |m{u]9
/** 709/'#- ^
* Yzr)UJl*I
* @author )?`G"(y
*/ 2F7( Y)
public class CountControl{ :/A7Z<u,
private static long lastExecuteTime=0;//上次更新时间 a+mrsyM
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 + /+> :
/** Creates a new instance of CountThread */ ;f?suawMv
public CountControl() {} 3uXRS,C
public synchronized void executeUpdate(){ 5aZbNV}-
Connection conn=null; [D%(Y
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PreparedStatement ps=null; `;j@v8n$*
try{ Q DVk7ks
conn = DBUtils.getConnection(); Rf4}((y7Y\
conn.setAutoCommit(false); |hl:!j.t
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ~a$h\F'6
for(int i=0;i<CountCache.list.size();i++){ Cer&VMrQK
CountBean cb=(CountBean)CountCache.list.getFirst(); G)8v~=Bv
CountCache.list.removeFirst(); }INj~d<:
ps.setInt(1, cb.getCountId()); ?3
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ps.executeUpdate();⑴ /@ww"dmqU
//ps.addBatch();⑵
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} -DuI
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//int [] counts = ps.executeBatch();⑶ v<3KxP'a
conn.commit(); a%nf
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}catch(Exception e){ MxgJ+
e.printStackTrace(); 3\}>nE
} finally{ Z% DJ{!Hnh
try{ oRZ98?Y\B
if(ps!=null) { 5>6:#.f%!e
ps.clearParameters(); s_;o1 K0
ps.close(); S4U}u l
ps=null; 5szJ.!(
} `r'$l<(4WV
}catch(SQLException e){} PrHoN2y5E
DBUtils.closeConnection(conn); s(T0lul
} )+Y"4?z~
} S6g_$Q7
public long getLast(){ ZEK,Z['
return lastExecuteTime; 'NMO>[.
} "Zfm4Nx"
public void run(){ IeZ9 "o h
long now = System.currentTimeMillis(); &\=Tm~
if ((now - lastExecuteTime) > executeSep) { -7KoR}Ck!
//System.out.print("lastExecuteTime:"+lastExecuteTime); #w3J+U 6r
//System.out.print(" now:"+now+"\n"); G?v!Uv8O
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); f(G1xw]]@Y
lastExecuteTime=now; h,?%,GI
executeUpdate(); 9W0*|!tQ,+
} I7wR[&L885
else{ {O:{F?
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); <+-=j
} f^-ot@w
} y/E:6w
} dF[|9%)
//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 &:&~[4>%a
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类写好了,下面是在JSP中如下调用。 Er;q s *f
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<% LZb<-vK"y
CountBean cb=new CountBean(); HC}vO0X4
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); h
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CountCache.add(cb); k'_f?_PBu
out.print(CountCache.list.size()+"<br>"); @ta:9wZ
CountControl c=new CountControl(); otdRz<C
c.run(); $KQ q~|
out.print(CountCache.list.size()+"<br>"); }L(ZLt8Q
%>