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: q*Oj5;
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CountBean.java 7'OR;b$
*
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/* ^&\pY
* CountData.java qnHjw Mi
* ]- 6q`'?[
* Created on 2007年1月1日, 下午4:44 %"cOX
* k')H5h+Q=
* To change this template, choose Tools | Options and locate the template under 6.9C4
* the Source Creation and Management node. Right-click the template and choose <ne?;P1L
* Open. You can then make changes to the template in the Source Editor. x+DETRLP
*/ ; GE6S{~-
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package com.tot.count; k`o8(zPb
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/** H |
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* 3dz{"hV
* @author rb}fP
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*/ fWC(L s
public class CountBean { +PnuWK$
private String countType; 7Vk9{x$z
int countId; rizjH+
/** Creates a new instance of CountData */ *o5[P\'6
public CountBean() {} QW'*^^
public void setCountType(String countTypes){ Pl!E$
this.countType=countTypes; ju5o).!bg
} EXF]y}n
public void setCountId(int countIds){ _xH<R
this.countId=countIds; QOgGL1)7-
} r@zs4N0WP
public String getCountType(){ H
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return countType; ~+d{:WY
} p0y|pD
public int getCountId(){ (f^/KB=
return countId; !vSq?!y6*P
} t^Lb}A#$4
} HY eCq9S
}
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CountCache.java s FJ:09L|
*- ~GVe
/* +8W5amk.P|
* CountCache.java R>Dr1fc}
* ).`v&-cK4E
* Created on 2007年1月1日, 下午5:01 ,;hpqu|
* 1JUj e
* To change this template, choose Tools | Options and locate the template under r*8a!jm?
* the Source Creation and Management node. Right-click the template and choose 4%zy$,|e
* Open. You can then make changes to the template in the Source Editor. Pwj|]0Y@
*/ $UdBZT-
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package com.tot.count; ]'7Au]Us`
import java.util.*; @U3z@v]s(h
/** AbhR*
* {qlcTc
* @author }ng?Ar[
*/ T`pDjT
public class CountCache { `&.qHw)
public static LinkedList list=new LinkedList(); '<vb_8.
/** Creates a new instance of CountCache */ [E%g3>/mt
public CountCache() {} .I EHjy\+
public static void add(CountBean cb){ ji>LBbnHdE
if(cb!=null){ rW|%eT*/'A
list.add(cb); 1_Ks*7vuq
} mA$86 X_
} eub}+~_?[
} [mQ1r*[j
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CountControl.java \2=I//YF
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/* 0:n"A,-p
* CountThread.java "f<gZsb
* ? %8%1d
* Created on 2007年1月1日, 下午4:57 \.oJ/++
* 5M~+F"Hl
* To change this template, choose Tools | Options and locate the template under 7]{t^*
* the Source Creation and Management node. Right-click the template and choose nSh~mP
* Open. You can then make changes to the template in the Source Editor. J_7@d]0R
*/ CshME\/
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package com.tot.count; KQb&7k.
import tot.db.DBUtils; V_, `?>O
import java.sql.*; iPV-w_HQ
/** T
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* @author U}DE9e{/!
*/ %FM26^
public class CountControl{ ab2Cn|F
private static long lastExecuteTime=0;//上次更新时间 #"~\/sb
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 G u_\ySV/y
/** Creates a new instance of CountThread */ &*'^uCna
public CountControl() {} P7zUf
public synchronized void executeUpdate(){ 6M`gy|"(~
Connection conn=null; Dq<DW2It>
PreparedStatement ps=null; ?H,f|nc
try{ vf@j d}?
conn = DBUtils.getConnection(); o?m1
conn.setAutoCommit(false); />}zB![(K
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); &4 KUXn[F
for(int i=0;i<CountCache.list.size();i++){ ;,6C&|n]w
CountBean cb=(CountBean)CountCache.list.getFirst(); -0<vmU
CountCache.list.removeFirst(); m,t{D,
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ps.setInt(1, cb.getCountId()); j;b>~_ U%
ps.executeUpdate();⑴ ~E((n
//ps.addBatch();⑵ [ dVBsi
} xM!9$v
//int [] counts = ps.executeBatch();⑶ !4D?X\~"%
conn.commit(); _b/zBFa%
}catch(Exception e){ Jn d_cJ ]a
e.printStackTrace(); .tGz, z}
} finally{ vV$t`PEY
try{ LQr!0p.i"
if(ps!=null) { RCYv 2=m>Q
ps.clearParameters(); jSHFY]2
ps.close(); 6;:D!},'c
ps=null; .%7Le|Fb"
} 9 Xl#$d5
}catch(SQLException e){} 6{^\7`
DBUtils.closeConnection(conn); YLTg(*
} 1goRO
} Q:Pp'[ RK
public long getLast(){ F(."nUrf
return lastExecuteTime; _0gdt4
} ,g}$u'A+d
public void run(){ "=
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long now = System.currentTimeMillis(); jUNt4
if ((now - lastExecuteTime) > executeSep) { ](Wa:U}Xs
//System.out.print("lastExecuteTime:"+lastExecuteTime); 2]9
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//System.out.print(" now:"+now+"\n"); |n tWMm:(
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ^7? WR?!
lastExecuteTime=now; _V1:'T8
executeUpdate(); GRYw_}Aa
} w{dRf!b69
else{ M&hNkJK*G
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 'R'hRMD9o
} d7G@Z|R3p
} 0fBwy/:
} SPdEO3
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 hp/pm6
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类写好了,下面是在JSP中如下调用。 vX6JjE!
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<% Rh)XYCM
CountBean cb=new CountBean(); y;fF|t<y
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); F1_,V?
CountCache.add(cb); i.W*Go+
out.print(CountCache.list.size()+"<br>"); gl`J(
CountControl c=new CountControl(); o$;&q
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c.run(); 3{~(_
out.print(CountCache.list.size()+"<br>"); W/,:-R&'>
%>