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: $3:O}X>
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CountBean.java lEiOE]
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/* bl`vT3
* CountData.java N:7;c}~
* CB%O8d #
* Created on 2007年1月1日, 下午4:44 ZNTOI]P&
* :~dI2e\:
* To change this template, choose Tools | Options and locate the template under TmO3hKaP
* the Source Creation and Management node. Right-click the template and choose 5R"(4a P
* Open. You can then make changes to the template in the Source Editor. OLgW.j:Ag
*/ SRpPLY{:F
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package com.tot.count; $tFmp)
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/** m}>#s3KPA
* *mj3 T
* @author [%yCnt
*/ Ok6c E
public class CountBean { J+20]jI
private String countType; ^bDh[O
int countId; j692M.A
/** Creates a new instance of CountData */ b#z{["%Zp
public CountBean() {} uS,XQy2
public void setCountType(String countTypes){ x5)YZ~5
this.countType=countTypes; lQnqPQY
} L]|[AyNu
public void setCountId(int countIds){ BD (
this.countId=countIds; o+T%n1$+V
} 2n8spLZYGY
public String getCountType(){ 1{7*0cv$iL
return countType; A5LTgGzaW
} a jyuk@
public int getCountId(){ VOK0)O>&
return countId; Yr9!</;T
} ]M#OS$_O@
} b )mU9
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CountCache.java ,8MUTXd@ V
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/* \ZPmPu9^(
* CountCache.java Gh #$[5&`
* F7~T=X)1
* Created on 2007年1月1日, 下午5:01 nVVQ^i}`G
* 2En^su$
* To change this template, choose Tools | Options and locate the template under 2PrUI;J$
* the Source Creation and Management node. Right-click the template and choose =u#xPI0:
* Open. You can then make changes to the template in the Source Editor. M@b:~mI[sw
*/ Y^~Dr|5%
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package com.tot.count; Pa-p9]gq
import java.util.*; OLS. 0UEc
/** W<AxctId
* vUU)zZB~
* @author =6N%;2`84
*/
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public class CountCache { W%bzA11l
public static LinkedList list=new LinkedList(); /T_@rm
/** Creates a new instance of CountCache */ 93aRWEu3
public CountCache() {} i)pAFv<$,
public static void add(CountBean cb){ CtO `t5
if(cb!=null){ !jeoB
list.add(cb); e
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} ;$Q&2}L[
} L6-zQztn
} wNX2*
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CountControl.java RZ#~^5DiO
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/* B]o5HA<k
* CountThread.java C;C= g1I}
* <FfdOK_
* Created on 2007年1月1日, 下午4:57 6pHn%yE*
* cn~M:LW23
* To change this template, choose Tools | Options and locate the template under Xj^Hy"HC^~
* the Source Creation and Management node. Right-click the template and choose 9Rg|o CP_
* Open. You can then make changes to the template in the Source Editor. n7r )wy
*/ .(7end<
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package com.tot.count; mjwh40x.o
import tot.db.DBUtils; )S;pYVVAl
import java.sql.*; "?<$>\@;
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/** l*`2EJ
* xElHYh(\
* @author xKl!{A9$w
*/ ?=22@Q}g
public class CountControl{ <ETR6r
private static long lastExecuteTime=0;//上次更新时间 iIe\m V
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 f""+jc1
/** Creates a new instance of CountThread */ z ]@ Q
public CountControl() {} M:4N'#`
public synchronized void executeUpdate(){ Vlk]
Connection conn=null; HX(Z(rcI
PreparedStatement ps=null; _|!FhZ
try{ eB$S d
conn = DBUtils.getConnection(); {Gd<+tQg
conn.setAutoCommit(false); _.ny<r:g
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); _wC4n }J
for(int i=0;i<CountCache.list.size();i++){ ]CFh0N|(L
CountBean cb=(CountBean)CountCache.list.getFirst(); VOj{&O2c
CountCache.list.removeFirst(); 7 fE
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ps.setInt(1, cb.getCountId()); SP,#KyWP0)
ps.executeUpdate();⑴ v7i5R !
//ps.addBatch();⑵ LZ97nvK
} mkR1iY
//int [] counts = ps.executeBatch();⑶ w
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conn.commit(); o
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}catch(Exception e){ zi-;7lT
e.printStackTrace(); )@X
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} finally{ Guc~]
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try{ IwE{Zvr
if(ps!=null) { ]7*Z'E
ps.clearParameters(); zSpL^:~
ps.close(); !OVTs3}
ps=null; <rO0t9OH
} HW{si]~q
}catch(SQLException e){} C
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DBUtils.closeConnection(conn); 4z_ >CiA
} lcv&/ A
} aetK<9L$
public long getLast(){ cWd\Ki
return lastExecuteTime; MQ9Nn|4
} 9rB,7%@EL
public void run(){ E5#Dn.!~
long now = System.currentTimeMillis(); k,~I>qg
if ((now - lastExecuteTime) > executeSep) { M!{;:m28X!
//System.out.print("lastExecuteTime:"+lastExecuteTime); }\9elVt'2
//System.out.print(" now:"+now+"\n"); R::0.*FF
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); n^svRM]eQ
lastExecuteTime=now; 1@ e22\
executeUpdate(); .=j]PckJO
} BD)5br].
else{ ]6`]+&
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); rRTAWAs%T
} Po%+:0oX
} cGevFlnh
} KxEy
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//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 {Hv/|.),hu
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类写好了,下面是在JSP中如下调用。 ST#OO!
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<% <Ae1YHUY
CountBean cb=new CountBean(); sXD.*D
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); o3_dHbdI
CountCache.add(cb); 9]ga\>v
out.print(CountCache.list.size()+"<br>"); ewo1^>
CountControl c=new CountControl(); X=:|v<E
c.run(); g UfLw
out.print(CountCache.list.size()+"<br>"); xq?9w$
%>