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: _6.@^\;
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CountBean.java Hh](n<Bs
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/* H4v%$R;K
* CountData.java o+OX^F0
* *tZ3?X[b
* Created on 2007年1月1日, 下午4:44 |U1u:=[
* BSy4
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* To change this template, choose Tools | Options and locate the template under 4V@0L
* the Source Creation and Management node. Right-click the template and choose !#]kzS0
* Open. You can then make changes to the template in the Source Editor. vr47PM2al
*/ (.oDxs()I
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package com.tot.count; myXGMN$i
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/** P
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* Brg0: 5H
* @author uJ=&++[
*/
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public class CountBean { Jp)PKS
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private String countType; nC/T$
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int countId; \K9Y@jnr
/** Creates a new instance of CountData */ X+emJ&Z$@
public CountBean() {} '%Oo1:wJ
public void setCountType(String countTypes){ .O~rAu*K
this.countType=countTypes; b,HXD~=
} &C,]c#-+
public void setCountId(int countIds){ 3S^Qo9S
this.countId=countIds; YA8/TFu<_
} yF` (GU
public String getCountType(){ P'_ aNU
return countType; xop\W4s_
}
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public int getCountId(){ )CL/%I,^
return countId; cv_O2Q4,@
} cP/( h
} ioTqT:.
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CountCache.java QQHC
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/* t@cBuV`9c
* CountCache.java _;(QMeR
* 3joMtRB>;
* Created on 2007年1月1日, 下午5:01 a3Z()|t>
* _["97>q
* To change this template, choose Tools | Options and locate the template under @J@bD+Q+0
* the Source Creation and Management node. Right-click the template and choose #lVSQZO~a
* Open. You can then make changes to the template in the Source Editor. N/^[c+J[E
*/ l%2B4d9"v
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package com.tot.count; |@-y+vbA*
import java.util.*; Dhg/>@tw
/** ; zy;M5l5.
* _x#r,1V+D
* @author i3Nt?FSN
*/ +xmZK<{<
public class CountCache { Git2Cet
public static LinkedList list=new LinkedList();
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/** Creates a new instance of CountCache */ r:^`005
public CountCache() {} lgAE`Os
public static void add(CountBean cb){ QQ,w:OjA0
if(cb!=null){ A@k=Mk
list.add(cb); )^^}!U#|e
} ~>$(5s2
} 10/3 -)+
} kS7T'[d
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CountControl.java ?~Vev D
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/* 9>@"W-
* CountThread.java 1G8t=IA%D
* n_] OYG>U
* Created on 2007年1月1日, 下午4:57 |om3* ]7
* QaEXk5>e
* To change this template, choose Tools | Options and locate the template under KQqQ@D&n
* the Source Creation and Management node. Right-click the template and choose tX}Fb0y
* Open. You can then make changes to the template in the Source Editor. =WP}RZ{S
*/ m7mC
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package com.tot.count; ]gj@r[
import tot.db.DBUtils; ~RE`@/wQ]
import java.sql.*; t!Av[K
/** *KV]MdS
* qdu:kA:]
* @author d{GXFT;0
*/ WI'csM;M#
public class CountControl{ ma*9O |v^
private static long lastExecuteTime=0;//上次更新时间 z#*GPA8Em:
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 kQBVx8Uq]
/** Creates a new instance of CountThread */ ck<4_?1]
public CountControl() {} ~GY;{
public synchronized void executeUpdate(){
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Connection conn=null;
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PreparedStatement ps=null; 7y`~T+
try{ 2W~2Hk=0+%
conn = DBUtils.getConnection(); ]X _&
conn.setAutoCommit(false); j({L6</x
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ~E`A,
for(int i=0;i<CountCache.list.size();i++){ 86} rz
CountBean cb=(CountBean)CountCache.list.getFirst(); ~d5{Q?T)
CountCache.list.removeFirst(); sQH.}W$C
ps.setInt(1, cb.getCountId()); x[oYN9O
ps.executeUpdate();⑴ >"nk}@
//ps.addBatch();⑵ j+ys&pDczm
} 1X9sx&5H
//int [] counts = ps.executeBatch();⑶ n2O7n@8
conn.commit(); C,z]q$4
}catch(Exception e){ wLUmRo56aR
e.printStackTrace(); >zhbipA
} finally{ O 1X
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try{ ZmHl~MR@
if(ps!=null) { {S&&X&A`v
ps.clearParameters(); *AN#D?X_
ps.close(); |m EJJg`"7
ps=null; XAFTLNV>
} O@Kr}8^,
}catch(SQLException e){} Ua3ERBX{
DBUtils.closeConnection(conn); 9VY_gi=vL
} ohyUvxvj
} t[
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public long getLast(){ ?^+|V,<
return lastExecuteTime; q
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} lJ,s}l7
public void run(){ |O+binq
long now = System.currentTimeMillis(); xO@OkCue
if ((now - lastExecuteTime) > executeSep) { p.IfJ|
//System.out.print("lastExecuteTime:"+lastExecuteTime); e)bqE^JP
//System.out.print(" now:"+now+"\n"); M*{e e0\`r
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); C]XDDr
lastExecuteTime=now; ~gDtj&F
executeUpdate(); FxT
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} 6u7HO-aa
else{ sR0nY8@F
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); WL~`L!_. A
} DpR%s",Q
} i!nl%%
} %?$"oWmenS
//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 JZ7-?
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类写好了,下面是在JSP中如下调用。 u60l -
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<% #WG(V%f]
CountBean cb=new CountBean(); OWkK]O
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); t8[:}[Jx
CountCache.add(cb); [6tQv<}^
out.print(CountCache.list.size()+"<br>"); @'y"D
CountControl c=new CountControl(); $7*Ml)H!9
c.run(); X[[=YCi0
out.print(CountCache.list.size()+"<br>"); m1hf[cg
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