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: R+*-i+]Q#7
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CountBean.java 8l>7=~Egp
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/* ' Ig:-
* CountData.java C6JwJYa
* 9oj#5Hq
* Created on 2007年1月1日, 下午4:44 9GX'+$R]
* FfRvi8
* To change this template, choose Tools | Options and locate the template under A(D>Zh6 o@
* the Source Creation and Management node. Right-click the template and choose u?4d<%5R!
* Open. You can then make changes to the template in the Source Editor. @?n~v^
*/ r1&eA% eh
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package com.tot.count; *ZkOZ
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/** ]>/oo =E
* "8$Muwm
* @author Pk3b#$+E
*/ ^/ff)'.J
public class CountBean { 79z/(T+
private String countType; t`-
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int countId; yHo#v:>?p
/** Creates a new instance of CountData */ LVaJyI@/>
public CountBean() {} Bh UGMK
public void setCountType(String countTypes){ m0i,Zw{eM
this.countType=countTypes; N0pA ,&
} :bq${
public void setCountId(int countIds){ *L&|4|BF2
this.countId=countIds; r,<p#4(>_
} W5uC5C*,l
public String getCountType(){ bXz*g`=;
return countType; <CcSChCg
} hRQw]
public int getCountId(){ $ghlrV;:ct
return countId; en"\2+{Cg
} }U^iVq*
} `.g'bZ<v/
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CountCache.java ]pWn%aGv*Y
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/* 2"QcjFW%
* CountCache.java *`40B6dEr
* z%;_h-
* Created on 2007年1月1日, 下午5:01 lMmP]{.>$
* C';Dc4j
* To change this template, choose Tools | Options and locate the template under 2c'<rkA
* the Source Creation and Management node. Right-click the template and choose *&z!y/
* Open. You can then make changes to the template in the Source Editor. 7*kTu0m
*/ 7sU+:a
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package com.tot.count; ?X+PNw|pf
import java.util.*; Y%!k'\n[2
/** {wl7&25
* 8{
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* @author cpm *m"Nk
*/ y5j ;Daq
public class CountCache { L@S1C=-/
public static LinkedList list=new LinkedList(); R].xT-1
/** Creates a new instance of CountCache */ n0FzDQt26
public CountCache() {} ><C9PS@
public static void add(CountBean cb){ ;>%wf3e
if(cb!=null){ QuBA'4ht
list.add(cb); RNopx3
} Jim5Ul
} ;*{Ls#
} SAU` u]E
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CountControl.java :7*9W|e
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/* y[/:?O}g4
* CountThread.java <OrQbrWQa
* h%5keiA
* Created on 2007年1月1日, 下午4:57 5S ) N&%
* XaaR>HljJ
* To change this template, choose Tools | Options and locate the template under Rw<O%i5/d
* the Source Creation and Management node. Right-click the template and choose .7+"KP:
* Open. You can then make changes to the template in the Source Editor. ~wu\j][2
*/ QJ%N80
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package com.tot.count; <r)5jf
import tot.db.DBUtils; Zul@aS
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import java.sql.*; gX`C76P!
/** {*"\68e
* NOFH
* @author Q]]M;(
*/ vCn~-Q
public class CountControl{ E;YD5^B
private static long lastExecuteTime=0;//上次更新时间 jw)c|%r>
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 `*xSn+wL`_
/** Creates a new instance of CountThread */ <Wd_m?z
public CountControl() {} BO+to.
public synchronized void executeUpdate(){ S
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Connection conn=null; TCK#bJ
PreparedStatement ps=null; +1a2Un
try{ 5'[yw:P-8
conn = DBUtils.getConnection(); T[-Tqi NT
conn.setAutoCommit(false); $,o@&QT?AT
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); v
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for(int i=0;i<CountCache.list.size();i++){ DG,m;vg+
CountBean cb=(CountBean)CountCache.list.getFirst(); '8LHX6FXK
CountCache.list.removeFirst(); F5H]$AjW
ps.setInt(1, cb.getCountId()); 6A4{6B
ps.executeUpdate();⑴ [xXV5 JU
//ps.addBatch();⑵ 55Xfu/hQ
} Xif>ZL?aXb
//int [] counts = ps.executeBatch();⑶ 3x=NSe|f
conn.commit(); L% T%6p_
}catch(Exception e){ [KMS/'; ]
e.printStackTrace(); `j'gt&
} finally{ id)J;!^;J
try{ H {uR+&<
if(ps!=null) { ,nWZJ&B
ps.clearParameters(); of'H]IZ
ps.close(); u}7r\MnwK,
ps=null; .PCbGPbk
} miV 8jaV
}catch(SQLException e){} !
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DBUtils.closeConnection(conn); 5*O]`Q7
} Mn*5oH
} uFG ;AY|
public long getLast(){ ]sqp^tQ`e
return lastExecuteTime; LAGg(:3f3
} -3SRGr
public void run(){ C9j5Pd5q1L
long now = System.currentTimeMillis(); "uBr]N:
if ((now - lastExecuteTime) > executeSep) { :eBp`dmn
//System.out.print("lastExecuteTime:"+lastExecuteTime); \wp8kSzC
//System.out.print(" now:"+now+"\n"); } 7i}dyQv}
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 7U-?Rd
lastExecuteTime=now; 3=_to7]
executeUpdate(); 1#x@
} lgC^32y
else{ f|,2u5
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); T'7x,8&2|
} mFyYn,Mu|
} N8Un42
} `nL^]i
//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 }b>e
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类写好了,下面是在JSP中如下调用。 a61?G!]
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<% |99Z&
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CountBean cb=new CountBean(); 84gj%tw'-
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); _2eL3xXha.
CountCache.add(cb); *B+YG^Yu^
out.print(CountCache.list.size()+"<br>"); X'5+)dj
CountControl c=new CountControl(); |RI77b:pX
c.run(); 7T?7KS
out.print(CountCache.list.size()+"<br>"); P#2;1ki>
%>