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: U%,;N\:_
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CountBean.java 8 >dq=0:
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/* OaNc9c"
* CountData.java <vLdBfw&N
* i :EO(`
* Created on 2007年1月1日, 下午4:44 /Mx.:.A&$
* kU(kU2u%9
* To change this template, choose Tools | Options and locate the template under #!1IP~
* the Source Creation and Management node. Right-click the template and choose Yg|"-
* Open. You can then make changes to the template in the Source Editor. BDp:9yau
*/ rFO_fIJno
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package com.tot.count; 'tut4SwC
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/** {70Ou}*
* ~K%k
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* @author Md?acWE*L
*/ c+wuC,
public class CountBean { u YabJqV
private String countType; ]'6'<S
int countId; K7S754m
/** Creates a new instance of CountData */ ysl8LK
public CountBean() {} i.F8
public void setCountType(String countTypes){ gu!](yEgl
this.countType=countTypes; [JZ h*A
} qr9Imr0w<
public void setCountId(int countIds){ !^]q0x
this.countId=countIds; +#9xA6,AE
} F/xCG nP-
public String getCountType(){ l_ZO^E~D_
return countType; F6DxvyANr
} {9 Db9K^
public int getCountId(){ *afejjW[
return countId; PRZ8X{h
} B3eNFS
} xg{VP7
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CountCache.java K:uQ#W.&
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/* C)U #T)
* CountCache.java A3<^ U
* 9n-T5WP
* Created on 2007年1月1日, 下午5:01 e"lD`*U8R
* (;C$gnr.C
* To change this template, choose Tools | Options and locate the template under 2c"/QT
* the Source Creation and Management node. Right-click the template and choose &+,:u*%
* Open. You can then make changes to the template in the Source Editor. ~K_ ]N/ >
*/ ,cPkx~w0
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package com.tot.count; j6RJC
import java.util.*; Lblet
/** J-b~4
* h)7v1,;w'
* @author $1b]xQ
*/ 7KeXWW/ d
public class CountCache { 3_C98ClE
public static LinkedList list=new LinkedList(); /i> ?i@O-
/** Creates a new instance of CountCache */ %7iUlO}}V
public CountCache() {} L,E-z_<p
public static void add(CountBean cb){ 5d> nIKW
if(cb!=null){ "k/;`eAP
list.add(cb); =!(S<];
} W;q#ZD(;
} )nJzSN=>$
} 1bT'u5&
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CountControl.java D xe-XKNc.
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/* l&\tf`~
* CountThread.java !NILpimi
* H U:1f)aa
* Created on 2007年1月1日, 下午4:57 '_k >*trV
* wEZ,49
* To change this template, choose Tools | Options and locate the template under >-UD]?>
* the Source Creation and Management node. Right-click the template and choose BvSdp6z9Iv
* Open. You can then make changes to the template in the Source Editor. i<'{Y
*/ ~K4k'
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package com.tot.count; 7zOhyl?
import tot.db.DBUtils; h_AJI\{"
import java.sql.*; ,\BfmC_i
/** 2;dM:FHLhO
* 0T7M_G'5Q
* @author ~o}moE/
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*/ +dDJes!]
public class CountControl{ <m~T>Ql1
private static long lastExecuteTime=0;//上次更新时间 FrgW7`s[A
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 YN_X0+b3C
/** Creates a new instance of CountThread */ x&QNP
public CountControl() {} 32M6EEmPG
public synchronized void executeUpdate(){ un.G6| S
Connection conn=null; xWd9%,mDNR
PreparedStatement ps=null; }*xC:A%aS
try{ N5[_a/
conn = DBUtils.getConnection(); ~l;yr
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conn.setAutoCommit(false); (PRaiE
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); s4!|v`+$M
for(int i=0;i<CountCache.list.size();i++){ H?rSP0.
CountBean cb=(CountBean)CountCache.list.getFirst(); cZPbD;e:
CountCache.list.removeFirst(); cjCE3V9X
ps.setInt(1, cb.getCountId()); Q,OkO?uY
ps.executeUpdate();⑴ ztRWIkI
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//ps.addBatch();⑵
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} %{N>c:2I$
//int [] counts = ps.executeBatch();⑶ Rh!L'?C
conn.commit(); L+v8E/W
}catch(Exception e){ xmCm3ekmpC
e.printStackTrace(); ~+sne7
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} finally{ U;x99Go:
try{ ]$* $0
if(ps!=null) { HY*l 4QK
ps.clearParameters(); Q3 K;kS
ps.close(); k/$Ja;
ps=null; z44
} h<PYE]?l
}catch(SQLException e){} :7HVBH
DBUtils.closeConnection(conn); ~Da
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} '?&B5C
} VZUZngw
public long getLast(){ D<+ bzC
return lastExecuteTime; QT7w::ht
} sV9{4T~#|
public void run(){ 1C^HCIH7J
long now = System.currentTimeMillis(); jEC'l]l
if ((now - lastExecuteTime) > executeSep) { TKj/6Jz|
//System.out.print("lastExecuteTime:"+lastExecuteTime); e_fg s>o`(
//System.out.print(" now:"+now+"\n"); },?-$eyX
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 7H8GkuO
lastExecuteTime=now; O^QR;<t'
executeUpdate(); P^'>dOI0w
} 9+WY@du+
else{ `DU'wB
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); Bbn832iMUY
} 5^G7pI7
} N[|by}@n
} A"P\4
//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 VZ9e~){xA
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类写好了,下面是在JSP中如下调用。 mSVX4XW<
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<% <8F->k1"3
CountBean cb=new CountBean(); 2dp*>F0L
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); \t&n
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CountCache.add(cb); 0lvb{Zd
out.print(CountCache.list.size()+"<br>"); -o!saX<
CountControl c=new CountControl(); 2c*VHIl;
c.run(); mvW^P`nB
out.print(CountCache.list.size()+"<br>"); \?5[RR
%>