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: sA+ }TNhq
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CountBean.java Amtq"<h9a
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/* AP3a;4Z#
* CountData.java ahusta
* y6g&Y.:o
* Created on 2007年1月1日, 下午4:44 cn3#R.G~
* ^
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* To change this template, choose Tools | Options and locate the template under ) ;EBz
* the Source Creation and Management node. Right-click the template and choose tj' \tW+s'
* Open. You can then make changes to the template in the Source Editor. on4HKeO
*/ iDpSj!x/_
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package com.tot.count; * `JYC
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/** akmkyrz '&
* eb?x9h
* @author &sl0W-;0
*/ y\/1/WjBn
public class CountBean { ))qy;Q,
private String countType; x`mG<Yt
int countId; oh4E7yN
/** Creates a new instance of CountData */ vx{}}/B]J
public CountBean() {} })'B<vq
public void setCountType(String countTypes){ !Z1@}`V&;
this.countType=countTypes; 0j^Kgx
} B`EJb71^Xy
public void setCountId(int countIds){ Lc}LGq!
this.countId=countIds; T6'^EZZY
} N:^n('U&j
public String getCountType(){ kXViWOXU^
return countType; EfqX
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} N"Z{5A
public int getCountId(){
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return countId; %U/(|wodd
} %[GsD9_-
}
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CountCache.java W<'m:dq
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/* Q1Kfi8h}'
* CountCache.java % 7hrk
* Kf3"Wf^q
* Created on 2007年1月1日, 下午5:01 n3WlZ!$
* aHD]k8m z
* To change this template, choose Tools | Options and locate the template under pd?Mf=>#
* the Source Creation and Management node. Right-click the template and choose G0Iw-vf
* Open. You can then make changes to the template in the Source Editor. M*0]ai|;
*/ &s(^@OayE
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package com.tot.count; )705V|v
import java.util.*; Zj(AJ* r
/** X;$+,&M"
* _YRFet[,m
* @author z 'Hw
*/ F~-(:7j
public class CountCache { u* eV@KK!
public static LinkedList list=new LinkedList(); /l3V3B7
/** Creates a new instance of CountCache */ GblA9F7
public CountCache() {} Y/F6\oh
public static void add(CountBean cb){ -E[Kml~U
if(cb!=null){ I^.Om])
list.add(cb); Zpt\p7WQ
} Cp\6W[2+B
} poE0{HOU
} RbB.q p
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CountControl.java PI {bmZ
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/* H_7/%noS5
* CountThread.java $ Gf(38[w
* 1C+13LE$U
* Created on 2007年1月1日, 下午4:57 }J}-//[A
* 2DA]i5
* To change this template, choose Tools | Options and locate the template under 3Tcms/n
* the Source Creation and Management node. Right-click the template and choose Da*?x8sSL
* Open. You can then make changes to the template in the Source Editor. J0WxR&%a)
*/ \
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package com.tot.count; hPkp;a #
import tot.db.DBUtils; =IZT(8
import java.sql.*; ,)cM3nu
/** L(6d&t'|-R
* %uDi#x.
* @author { l/U6](
*/ .^`{1%
public class CountControl{ ,>a&"V^k
private static long lastExecuteTime=0;//上次更新时间 h,:m~0gmj
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 B`)BZ,#p
/** Creates a new instance of CountThread */ u[;\y|75
public CountControl() {} M)Z7k/=<P
public synchronized void executeUpdate(){ ;fTKfa
Connection conn=null; HQdxL*N%^
PreparedStatement ps=null; bW427B0
try{
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conn = DBUtils.getConnection(); BKCiIfkZ
conn.setAutoCommit(false); 5Pc;5
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 8Al{+gx@?
for(int i=0;i<CountCache.list.size();i++){ v4TQX<0s
CountBean cb=(CountBean)CountCache.list.getFirst(); ktXM|#
CountCache.list.removeFirst(); N{!i=A
ps.setInt(1, cb.getCountId()); {lzWrUGO
ps.executeUpdate();⑴ QW~E&B%
//ps.addBatch();⑵ 6Igz:eX
} ,<_A2t 2
//int [] counts = ps.executeBatch();⑶ 4\N;2N
conn.commit(); !qQl@j O
}catch(Exception e){ y-b%T|p9
e.printStackTrace(); 1s&zMWC
} finally{ u/0h$l
try{ WDYeOtc
if(ps!=null) { yWc$>ne[L
ps.clearParameters(); tKuwpT1Qc
ps.close(); "S]0
ps=null; q[_VuA]&
} M]
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}catch(SQLException e){} KK4`l}Fk:n
DBUtils.closeConnection(conn); O`kl\K*R7
} 3*XNV
} }"H,h)T
public long getLast(){ R%WCH?B<}
return lastExecuteTime; r|8d
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} cl3K<'D
public void run(){ a.\:T,cP>
long now = System.currentTimeMillis(); 3ZPWze6
if ((now - lastExecuteTime) > executeSep) { jRlYU`?
//System.out.print("lastExecuteTime:"+lastExecuteTime); 7aRi5
//System.out.print(" now:"+now+"\n"); p`dU2gV
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 2 a)xTA#
lastExecuteTime=now; s\(k<Ks
executeUpdate(); |^I0dR/w:
}
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else{ pU}(@oy
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); !-x$L>1$
} Ta0|+IYk<
} ?!:ha;n
} \:'/'^=#|
//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 Rok7n1gW
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类写好了,下面是在JSP中如下调用。 Xl{P8L
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<% 558V_y:
CountBean cb=new CountBean(); 8'[7
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ~W'{p
CountCache.add(cb);
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out.print(CountCache.list.size()+"<br>"); mDABH@R
CountControl c=new CountControl(); {4}yKjW%z
c.run(); n,(sBOQ
out.print(CountCache.list.size()+"<br>"); =ho}oL,ZO
%>