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: 9y/gWE
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CountBean.java \@]/ks=K
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/* s':fv[%
* CountData.java H`!%"
* YDEUiZ~
* Created on 2007年1月1日, 下午4:44 ejY|o
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* Efo,5
* To change this template, choose Tools | Options and locate the template under qucw%hJ r
* the Source Creation and Management node. Right-click the template and choose $.Fti-5
* Open. You can then make changes to the template in the Source Editor. )3O0:]<H
*/ Y XC?q
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package com.tot.count; HA}pr6Z
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/** #@h3#IC
* (GnwK1f
* @author ). +!/x
*/ -!]Ie4"
public class CountBean { QW~-+BD
private String countType; 9:tvkl
int countId; n ,<`.^
/** Creates a new instance of CountData */ F^iv1b
public CountBean() {} F_Q,j]0
public void setCountType(String countTypes){ \L14rQ
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this.countType=countTypes; H]:z:AAvX
} _E({!t"`
public void setCountId(int countIds){ ,l[h9J
this.countId=countIds; mi~BdBv
} 79J@`
public String getCountType(){ G$\2@RT9[
return countType; BV=L.*
} LM_/:
public int getCountId(){ Pw4j?pv2
return countId; p_hljgOV
} t(SSrM]
} mPR(4Ol.
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CountCache.java 1c=Roiq
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/* {.7ve<K
* CountCache.java Ln;jB&t
* g*9jPwdG
* Created on 2007年1月1日, 下午5:01 $"Oy }
* \R&4Nu2F
* To change this template, choose Tools | Options and locate the template under ns.[PJ"8
* the Source Creation and Management node. Right-click the template and choose )]2yTG[
* Open. You can then make changes to the template in the Source Editor. @a.Y9;O
*/ wE K@B&DV
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package com.tot.count; @Yua%n6]#D
import java.util.*; U:]b&I
/** q?C)5(
* K7&A^$`
* @author xNt
*/ tMaJ; 4
public class CountCache { 02]9OnWw
public static LinkedList list=new LinkedList(); )=\W
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/** Creates a new instance of CountCache */ UXB[3SP
public CountCache() {} @Kri)U
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public static void add(CountBean cb){ \mZ\1wzn'{
if(cb!=null){ g;(r@>U.r
list.add(cb); w;$@ </
} S3"js4a
} M%7H-^{
} !M~p __
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CountControl.java QjfQoT F
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/* S EY
* CountThread.java Fi{~UOZg
* (sw1HR
* Created on 2007年1月1日, 下午4:57 \\jB@O
* %l@Q&)f8e
* To change this template, choose Tools | Options and locate the template under sY,!Ir`/`
* the Source Creation and Management node. Right-click the template and choose ;_0)f
* Open. You can then make changes to the template in the Source Editor. d#T8|#O"
*/ P[{w23`4
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package com.tot.count; zOq~?>Ms6
import tot.db.DBUtils; )@Yp;=l
import java.sql.*; f}bUuQrH-!
/** ]>@;
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* l;>#O
* @author V"VWHAu*.w
*/ %+$P<Rw7
public class CountControl{ xmtbSRgK9
private static long lastExecuteTime=0;//上次更新时间 ' U(v
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 )61CrQiY
/** Creates a new instance of CountThread */
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public CountControl() {} dJ`Fvj
public synchronized void executeUpdate(){ $4kc i@.
Connection conn=null; XKp %7;
PreparedStatement ps=null; yz-IZt(
try{ sZ-]yr\E"
conn = DBUtils.getConnection(); uVqJl{e\
conn.setAutoCommit(false); ovCk:Vz
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ,TU!W|($
for(int i=0;i<CountCache.list.size();i++){ uMF\3T(x4
CountBean cb=(CountBean)CountCache.list.getFirst(); 1$idF
CountCache.list.removeFirst(); B@*BcE?
ps.setInt(1, cb.getCountId()); bl\44VK2'
ps.executeUpdate();⑴ $X5~9s1Wl
//ps.addBatch();⑵ -mZo`
} ?{q w
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//int [] counts = ps.executeBatch();⑶ l1c&a[M)
conn.commit(); ,$3
}catch(Exception e){ u*Oz1~
e.printStackTrace(); c%)uG _
} finally{ [p@NzS/
try{ 4:cbasy
if(ps!=null) { mU_?}}aK,
ps.clearParameters(); M@Q=!!tQ(
ps.close(); UA,&0.7
ps=null; +nd'Uf
} @Risabn
}catch(SQLException e){} ,@!8jar@w}
DBUtils.closeConnection(conn);
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} *NV`6?o@6
} K_`*ZV{r
public long getLast(){ w;QDQ
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return lastExecuteTime; $E|W|4N
} #`GW7(M
public void run(){ G"MpA[a_
long now = System.currentTimeMillis(); zx(j6
if ((now - lastExecuteTime) > executeSep) { Kggf!\MR8
//System.out.print("lastExecuteTime:"+lastExecuteTime); 1:7>Em<s
//System.out.print(" now:"+now+"\n"); D4'?
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n");
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lastExecuteTime=now; 0P/A
executeUpdate(); O(
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} ~B(]0:
else{ d5A!kU _.
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); =
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} q~trn'X>
} |!%A1 wp#
} *U54x
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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 QVn0!R{
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类写好了,下面是在JSP中如下调用。 U]R?O5K
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<% wt2S[:!p
CountBean cb=new CountBean(); PR|Trnd&D
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); lha)'
CountCache.add(cb); $%r|V*5
out.print(CountCache.list.size()+"<br>"); v/+ dx/
CountControl c=new CountControl(); *,
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c.run(); FZ=6x}QZ
out.print(CountCache.list.size()+"<br>"); g#[9O'H
%>