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: n,d)Wwe_`y
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CountBean.java A"z9t#dv@
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/* `FEa(Q+s
* CountData.java
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* TbaZFLr
* Created on 2007年1月1日, 下午4:44 \!xCmQ
* Y::O*I2
* To change this template, choose Tools | Options and locate the template under je5[.VT M
* the Source Creation and Management node. Right-click the template and choose :a^/&LbLm
* Open. You can then make changes to the template in the Source Editor. q}!h(-y}5n
*/ 80ox$U
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package com.tot.count; H~^)^6)^T
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/** e^'|<0J
* i\O^s ]
* @author )*`h)`\y
*/ x[0O*ty-*<
public class CountBean { S+#|j
private String countType; |#sOa
int countId; (k8}9[3G
/** Creates a new instance of CountData */ &36SX<vZ
public CountBean() {} KK6n"&TVa
public void setCountType(String countTypes){ wSw> UU
this.countType=countTypes; i4]oE&G
} j8nkNE]&
public void setCountId(int countIds){ Lx tgf2r
this.countId=countIds; 0zE@?.
} k(M:#oA!
public String getCountType(){ [Ky3WppR
return countType; x
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} >lfuo
public int getCountId(){ ,ryL("G
return countId; R1D ;
} u`&lTJgF/O
} #y[U2s Se
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CountCache.java u88wSe<\X
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/* !LzA
* CountCache.java G[`1Yw$
* o+B)
* Created on 2007年1月1日, 下午5:01 @Ns[qn;9
* 6i2%EC9
* To change this template, choose Tools | Options and locate the template under L7d1)mV
* the Source Creation and Management node. Right-click the template and choose 0{g*\W*+~
* Open. You can then make changes to the template in the Source Editor. |Fi5/$S.
*/ 1`YU9?
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package com.tot.count; DzQ
import java.util.*; cP D_=.&
/** &w#!
* c!_c, vwrn
* @author
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*/ GB35o uE
public class CountCache { #c5jCy}n
public static LinkedList list=new LinkedList(); N+h05`
/** Creates a new instance of CountCache */ Pc_aEBq
public CountCache() {} D}q"^"#T
public static void add(CountBean cb){ "4;nnq
if(cb!=null){ _'LZf=V0
list.add(cb); -(t7>s
} /("7*W 2
} ;8eKAh
} d&[RfZ`
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CountControl.java Qr9;CVW
y TD4 {} Z*ip=FYR
public synchronized void executeUpdate(){ P"8Ix
Connection conn=null; N+=|WeZ
PreparedStatement ps=null; 80Dn!9j*
try{ RqtBz3v
conn = DBUtils.getConnection(); a:fP
conn.setAutoCommit(false); U}RBgPX!
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); UowvkVa
for(int i=0;i<CountCache.list.size();i++){ y
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CountBean cb=(CountBean)CountCache.list.getFirst(); <Gi%+I@szl
CountCache.list.removeFirst(); +cfEyiub
ps.setInt(1, cb.getCountId()); eF,F<IJT{
ps.executeUpdate();⑴ MLu!8dgI
//ps.addBatch();⑵ W<r<K=`5P
} |QDoi[
*
//int [] counts = ps.executeBatch();⑶ m$fEk,d
conn.commit(); (-21h0N[V
}catch(Exception e){ C/!.VMl^
e.printStackTrace(); 4|=>gdW)KN
} finally{ ?vFy3
try{ 9%"7~YCDas
if(ps!=null) { U`%t&7)
ps.clearParameters(); LE\=Y;%
ps.close(); ->8Kd1^F
ps=null; Yv5H41o"
} u4C9ZYN
}catch(SQLException e){} *Jd"3Si/
DBUtils.closeConnection(conn); _&uJE&xl}
} #i[:oC6m:
} `RL
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public long getLast(){ uiVNz8H
return lastExecuteTime; "lI-/G
} V4:/LNq_]
public void run(){ Io1j%T#ZT
long now = System.currentTimeMillis(); 7nek,8b
if ((now - lastExecuteTime) > executeSep) { HIXAA?_eh=
//System.out.print("lastExecuteTime:"+lastExecuteTime); JWixY/
//System.out.print(" now:"+now+"\n"); ^#HaH
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 7k(}U_v
lastExecuteTime=now; !6KX^j-
executeUpdate(); p~ b4TRvA6
} %S`&R5
else{ \c<
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); fF(2bVKP:
} ;
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} |ia5Mr"t
} eV[{c %wN:
//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 @C)s4{V
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类写好了,下面是在JSP中如下调用。 VJ~D.ec
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<% V\cbIx(Z^
CountBean cb=new CountBean(); <]qNjsdb9"
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ?woL17Gt
CountCache.add(cb); wa"0`a:`;
out.print(CountCache.list.size()+"<br>"); rwRZGd *p
CountControl c=new CountControl(); {821e&r
c.run(); |U%NPw5
out.print(CountCache.list.size()+"<br>"); 'J,UKK\5
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