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: ?4vf2n@
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CountBean.java r*CI6yP
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/* \}[{q
* CountData.java jp?;8rS3
* *<Yn
* Created on 2007年1月1日, 下午4:44 /<,LM8n
* @LZ'Qc
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* To change this template, choose Tools | Options and locate the template under ,*ZdMw!
* the Source Creation and Management node. Right-click the template and choose #/!fLU@
* Open. You can then make changes to the template in the Source Editor. <J" 7ufHSQ
*/ XG2&_u&
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package com.tot.count; ^|-*amh
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/** O&h3=?O&B
* =g|e-XC
* @author t-7^deG'/n
*/ j}}:&>;
public class CountBean { |eH>55 b
private String countType; Ct2m l
int countId; IO3`/R-
/** Creates a new instance of CountData */ NGZEUtj
public CountBean() {} #'m&<g,
public void setCountType(String countTypes){ } m5AO 4:
this.countType=countTypes; v%N/mL+5L
} :KY920/,
public void setCountId(int countIds){ )*<=:
this.countId=countIds; $h"Ht2/ J
} CZaUrr
public String getCountType(){ evOyTvc
return countType; y\Su!?4!
} ;{'{*g[
public int getCountId(){ 5MUM{(C
return countId; mqxgrb7
} T4MB~5,i
} ~gU.z6us
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CountCache.java )9LlM2+y
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/* F|.,lb |L
* CountCache.java GiI|6z!
* IoUQ~JviA
* Created on 2007年1月1日, 下午5:01 6b&<5,=d:
* m]LR4V6k|
* To change this template, choose Tools | Options and locate the template under "o.V`Bj
* the Source Creation and Management node. Right-click the template and choose {@j0?s
* Open. You can then make changes to the template in the Source Editor. &+F|v(|r
*/ .
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package com.tot.count; F~j
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import java.util.*; / O@'XWW
/** }2dz];bR
* Bc1[^{`bq^
* @author i$MYR @
*/ \GA6;6%Oo
public class CountCache { 15PFnk6E|
public static LinkedList list=new LinkedList(); JBX#U@k>I
/** Creates a new instance of CountCache */ qbu>YTj
public CountCache() {} S-)mv'Al'F
public static void add(CountBean cb){ 4?Mb>\n%<^
if(cb!=null){ w
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list.add(cb); pbg[\UJyd
} v,6
} 0V{a{>+
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CountControl.java %{GYTc \'X
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/* Qn`$xY9mT
* CountThread.java <?|v-(E
* -"*UICd
* Created on 2007年1月1日, 下午4:57 YbS$D
* HzADz%~
* To change this template, choose Tools | Options and locate the template under \;w$"@9
* the Source Creation and Management node. Right-click the template and choose ^H]q[XFR
* Open. You can then make changes to the template in the Source Editor. F3k]*pk8w
*/ d)V"tSC,
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package com.tot.count; L0ZgxG3:g
import tot.db.DBUtils; l+# l\q%l
import java.sql.*; 2Eq?^ )s
/** QiDf,$t|,
* WSA;p=_
* @author a`SQcNBf*
*/ S 6e<2G=O
public class CountControl{ o80?B~o
private static long lastExecuteTime=0;//上次更新时间 z=ItKoM*<
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 MF+J3)
/** Creates a new instance of CountThread */ ~lB im$o
public CountControl() {} j9)WInYc:
public synchronized void executeUpdate(){ 9OIX5$,S;
Connection conn=null; (dSf>p r2
PreparedStatement ps=null; G01 J1Ll}
try{ XL@Y!
conn = DBUtils.getConnection(); 5HWVK .
conn.setAutoCommit(false); Z0yy<9q]2
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ?_S f
for(int i=0;i<CountCache.list.size();i++){ ["FC
CountBean cb=(CountBean)CountCache.list.getFirst(); i={ :6K?^
CountCache.list.removeFirst(); q:OSQ~U_
ps.setInt(1, cb.getCountId()); h@nNm30i
ps.executeUpdate();⑴ w h4WII
//ps.addBatch();⑵ $L|YllD%
} Koh`|]N
//int [] counts = ps.executeBatch();⑶ @8[3]<
conn.commit();
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}catch(Exception e){ 8)(<U/
e.printStackTrace(); Xy_ <Yqx}
} finally{ r >%reS
try{ rL+K Sb
if(ps!=null) { "BN-Jvb7q
ps.clearParameters(); P( z#Wk
ps.close(); 8;'fWV?
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ps=null; Z<j(ZVO
} gO
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}catch(SQLException e){} QBi&Q%p iy
DBUtils.closeConnection(conn); lTNfTO^
} B~p` 3rC
} "2cJ'n/L
public long getLast(){ %lL^[`AR
return lastExecuteTime; 7"L`|O?8)
} +q z"+g
public void run(){ ^:JZ.r
long now = System.currentTimeMillis(); F"7dN *7
if ((now - lastExecuteTime) > executeSep) { L%D:gy9o
//System.out.print("lastExecuteTime:"+lastExecuteTime); Qg
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//System.out.print(" now:"+now+"\n"); '%!'1si
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); EH;w
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lastExecuteTime=now; L,I5/K6
executeUpdate(); \Qp #utC0s
} x)'4u6;d
else{ YuO-a$BP
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); JXR_klx
} g.CUo:c
} A]VcQ_e
} C)2Waj}
//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 JaC
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类写好了,下面是在JSP中如下调用。 k!/"J
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<% 8"2
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CountBean cb=new CountBean(); 6#NptXB
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); b>R/=tx
CountCache.add(cb); !L3M\Q0
out.print(CountCache.list.size()+"<br>"); cE7xNZ;Bh
CountControl c=new CountControl(); FB<#N+L\
c.run(); zB 6u%u WR
out.print(CountCache.list.size()+"<br>"); }P[xZ_S1
%>