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: ^{Mx?]z
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CountBean.java fxiq,o0
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/* JXvHsCd?
* CountData.java &=s{ +0
* r%xNfTa
* Created on 2007年1月1日, 下午4:44 dn`#N^Od
* (T`x-wTl
* To change this template, choose Tools | Options and locate the template under r9u*c
* the Source Creation and Management node. Right-click the template and choose Zl* HT%-5
* Open. You can then make changes to the template in the Source Editor. -4HI9Czts
*/ W;0_@!?mr}
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package com.tot.count; $x`U)pv
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/** \W$>EH
* qP]Gl--q{
* @author ~}TVM%0RTq
*/ 57r\s8
public class CountBean { ?DpMR/
private String countType; +L X&1GX
int countId; ok[R`99
/** Creates a new instance of CountData */ .0s/O
public CountBean() {} 9^jO^[>
public void setCountType(String countTypes){ ,',fO?Qv'
this.countType=countTypes; "w|GIjE+
} oR3$A :!P=
public void setCountId(int countIds){ `#9ZP
this.countId=countIds; Lqz}h-Ei
} >Axe7<l
public String getCountType(){ i>0bI^H
return countType; Cu9,oU+N
} sg9ZYWcL
public int getCountId(){ s[Njk@y,
return countId; J)o~FC]b*
} 8
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} 6i&WF<%D
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CountCache.java )b5MP1H
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/* R':a,6O
* CountCache.java )~!Gs/w6
* N(F9vZOs
* Created on 2007年1月1日, 下午5:01 VpJ2Qpd=
* !q$IB?8
* To change this template, choose Tools | Options and locate the template under ~IlgcCF
* the Source Creation and Management node. Right-click the template and choose McA,
* Open. You can then make changes to the template in the Source Editor. WI~';dK2]
*/ d)q{s(<;
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package com.tot.count; ?2.<y_1
import java.util.*; @dO~0dF
/** Na[bCt
* "esV#%:#J
* @author ?K}/b[[0v
*/ f$/Daq <M
public class CountCache { <v0 d8
public static LinkedList list=new LinkedList(); F5EKWP
/** Creates a new instance of CountCache */ b/2t@VlL
public CountCache() {} 6IeHZ)jGj
public static void add(CountBean cb){ ~Uga=&
if(cb!=null){ 'm-s8]-W
list.add(cb); Vwl`A3Y
} LoNz
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} w'U;b
} O^`Y>>a
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CountControl.java IWKQU/l!
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/* ]k >S0
* CountThread.java [?]s((A~B
* _L&C4 <e'
* Created on 2007年1月1日, 下午4:57 $g#%
* Soq
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* To change this template, choose Tools | Options and locate the template under oSTGs@EK
* the Source Creation and Management node. Right-click the template and choose lgre@M]mg
* Open. You can then make changes to the template in the Source Editor. @XB/9!
*/ B&<Z#C:I
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package com.tot.count; ?1 ?m4i
import tot.db.DBUtils; -_A0<A .
import java.sql.*; LD#]"k
/** *Q5/d9B8TN
* l"O=x t`m{
* @author ].`i`.T
*/ N"FQMxqm
public class CountControl{ Z?1.Y7Npr
private static long lastExecuteTime=0;//上次更新时间 -YRF^72+
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 C3WqUf<8`{
/** Creates a new instance of CountThread */ 8+
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public CountControl() {} "EHwv2Hm>
public synchronized void executeUpdate(){ oXb}6YC
Connection conn=null; {6v+
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PreparedStatement ps=null; "4i(5|whp?
try{ =j}]-!
conn = DBUtils.getConnection(); C\
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conn.setAutoCommit(false); 3kQky
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); q[**i[+%
for(int i=0;i<CountCache.list.size();i++){ Z>M0[DJ_
CountBean cb=(CountBean)CountCache.list.getFirst(); |<9R%
CountCache.list.removeFirst(); X[|-F3o
ps.setInt(1, cb.getCountId()); eX$u
ps.executeUpdate();⑴ 42X[Huy]
//ps.addBatch();⑵ Y+j|T`d
} Smg,1,=
//int [] counts = ps.executeBatch();⑶ q=g;TAXZl
conn.commit(); !J'BAq[x
}catch(Exception e){ )1&[uE#L
e.printStackTrace(); 'TezUBRAz
} finally{ B!rY\ ?W
try{ |Y2u=B
if(ps!=null) { \*a7DuVw
ps.clearParameters(); o{nBtxZ"
ps.close(); 62a{Ggs{
ps=null; iv:[]o
} B-'Xk{
}catch(SQLException e){} 57rc|]C
DBUtils.closeConnection(conn); So,EPB+
} OG/R6k.
} $)z(4Ev
public long getLast(){ K^?/
return lastExecuteTime; |*jnJWH4:
} ~b\bpu
public void run(){ M~p=OM<
long now = System.currentTimeMillis(); +-K-CXt
if ((now - lastExecuteTime) > executeSep) { 8^^Xr
//System.out.print("lastExecuteTime:"+lastExecuteTime); 4GeWo@8h
//System.out.print(" now:"+now+"\n"); w}YO+
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); O-5H7Kd-
lastExecuteTime=now; ~S#Le
executeUpdate(); d#Ql>PrY
} ,7z.%g3+z
else{ `A3"*,|z
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); PzNk: O
} l]^uVOX
} l<! ?`V6}
} A0
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//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 _}{C?611c
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类写好了,下面是在JSP中如下调用。 h@@2vs2
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<% /vBOf;L
CountBean cb=new CountBean(); C.Y]PdYyj
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); FE" ksi 9
CountCache.add(cb); [f&ja[m q
out.print(CountCache.list.size()+"<br>"); ~UEft
CountControl c=new CountControl(); *oKc4S+
c.run(); b~WiE?
out.print(CountCache.list.size()+"<br>"); pa4zSl
%>