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: s@Loax6@B
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CountBean.java OL^DuoB4q
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/* wUfPnAD.'
* CountData.java E^m)&.+'M
* $Rn9*OKr
* Created on 2007年1月1日, 下午4:44 vE)d0l"
* P7REE_<1
* To change this template, choose Tools | Options and locate the template under BqdGU-Q
* the Source Creation and Management node. Right-click the template and choose 9;rZ )QD
* Open. You can then make changes to the template in the Source Editor. ;yCtk ~T%
*/ f#hmMa
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package com.tot.count; +ZV?yR2yn
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/** ;&kZ7%
* 8%xiHPVg
* @author ~H"-km"@
*/ woN
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public class CountBean { ?,C'\8'
private String countType; O* )BJOPa
int countId; Zm(}~C29
/** Creates a new instance of CountData */ Uo[`AzD3
public CountBean() {} ]iZ-MG)J
public void setCountType(String countTypes){ ;<%d^
this.countType=countTypes; PWyFys
} +eop4 |Z
public void setCountId(int countIds){ y+izC+
this.countId=countIds; A2Iqn5
} g91xUG
public String getCountType(){ ZS@R ?
return countType; >feeVk
} 8^R~qpg%
public int getCountId(){ `_"?$ v2F
return countId; C\|HN=2eh
} 2d<`dQY{l3
} Xob(4
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CountCache.java %;J$ h^
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/* cCIs~*D
* CountCache.java +!G)N~o
* 5j _[z|W2
* Created on 2007年1月1日, 下午5:01 tMo=q7ig
* U;gy4rj
* To change this template, choose Tools | Options and locate the template under k_Lv\'Ok
* the Source Creation and Management node. Right-click the template and choose HDz"i
* Open. You can then make changes to the template in the Source Editor. 9'KOc5@l^
*/ =S\pI
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package com.tot.count; u:,B&}j
import java.util.*; :%U
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/** w2K>k/v{-
* 6*I=%
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* @author t3!~=U
*/ ~$7YEs)
public class CountCache { 0f;|0siTAm
public static LinkedList list=new LinkedList(); u0$}VO5/a
/** Creates a new instance of CountCache */ wqyF"^It"
public CountCache() {} s##XC^;p[
public static void add(CountBean cb){ T'N/A9{q
if(cb!=null){ gpCWXz')i
list.add(cb); &@qB6!^
} V~t;
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} c{jTCkzq
} t /lU*
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CountControl.java B""=&(Yu
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/* T3-/+4$0v
* CountThread.java YCyh+%Q(
* mH'om
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* Created on 2007年1月1日, 下午4:57 (]5gYi
* s]xn&rd_
* To change this template, choose Tools | Options and locate the template under `>0(N.'T
* the Source Creation and Management node. Right-click the template and choose |Lc.XxBkc
* Open. You can then make changes to the template in the Source Editor. 5g 2:o^
*/ l585L3i
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package com.tot.count; 6O'Y@9#
import tot.db.DBUtils; }jg,[jw_"X
import java.sql.*; >E>'9@Uh
/** qi8~bQ{rH
* f^[m~
* @author {65_k
*/ t\\<+^[%
public class CountControl{ gyCXv0*z
private static long lastExecuteTime=0;//上次更新时间 ^K^rl9
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ''.\DC~K
/** Creates a new instance of CountThread */ QVD^p;b
public CountControl() {} z~;@Mo"*f
public synchronized void executeUpdate(){ +@\=v}:
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Connection conn=null; IY|>'}UU#
PreparedStatement ps=null; 3[%n@i4H|
try{ .?r}3Ch
conn = DBUtils.getConnection(); N$cAX^~
conn.setAutoCommit(false); D]K?ntS[*
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); |1/?>=dDm
for(int i=0;i<CountCache.list.size();i++){ :A,7D(H|
CountBean cb=(CountBean)CountCache.list.getFirst(); I&5cUj{GX-
CountCache.list.removeFirst(); :n oZ
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ps.setInt(1, cb.getCountId()); ^]$rh.7&
ps.executeUpdate();⑴ ~&+8m=
//ps.addBatch();⑵ G\*`%B_ n
} A)nE+ec1
//int [] counts = ps.executeBatch();⑶ {CGk9g"`
conn.commit(); !]P=v`B.
}catch(Exception e){ ='HLA-uT
e.printStackTrace(); g"D:zK)
} finally{ Kuh)3/7
try{ `W4Is~VVv
if(ps!=null) { Q7?[@2HN
ps.clearParameters(); 8{p#Nl?U1
ps.close(); kT&GsR/
ps=null; ?O/!pUAu
} )'`@rq!
}catch(SQLException e){} FX/f0C3CK
DBUtils.closeConnection(conn); 7T=:dv
} g|)yM^Vqr6
} ?;p45y~n%
public long getLast(){ s%)>O{{)
return lastExecuteTime; 4zf(
} n*N`].r#{=
public void run(){ \p J<@
long now = System.currentTimeMillis(); 6am<V]Hw0F
if ((now - lastExecuteTime) > executeSep) { 2B]mD-~
//System.out.print("lastExecuteTime:"+lastExecuteTime); +InFv"wt
//System.out.print(" now:"+now+"\n"); 4J2C#Cs
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); O4,?C)
lastExecuteTime=now; NQ\<~a`Eq
executeUpdate(); :z+l=d:4
} f >\~h,SLL
else{ ~"WN4
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ] U[4r9V
} oo!JAv}~
} [L>AU;
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} /3d6Og
//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 ?,*KA Gg%
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类写好了,下面是在JSP中如下调用。 qjLFgsd
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<% DgC;1U'
CountBean cb=new CountBean(); W/<