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: CEc(2q+%i
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CountBean.java m6n%?8t
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/* /W BmR R
* CountData.java f pq|mY
* 83t/\x,Q
* Created on 2007年1月1日, 下午4:44 |vl~B|",
* *URT-+'
* To change this template, choose Tools | Options and locate the template under -9,~b9$
* the Source Creation and Management node. Right-click the template and choose Rk3
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* Open. You can then make changes to the template in the Source Editor. Zp~yemERr
*/ 1(IZ,*i
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package com.tot.count; /3~L#jS
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/** d-+jb<C&
* TaBya0-
* @author @=dv[P"jn
*/ nM2<u[{gF
public class CountBean { xwof[BnEZ
private String countType; N\g=9o|Q
int countId; #5)/B
/** Creates a new instance of CountData */ j7kX"nz
public CountBean() {} f?)7MR=
public void setCountType(String countTypes){ qfE0J;e
this.countType=countTypes; $$1t4=Pz
} ~at@3j}W
public void setCountId(int countIds){ ge
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this.countId=countIds; 'A7!@hVy
} j0; ~2W#G*
public String getCountType(){ ZxwrlaA
return countType; :! oJmvy
} >aO.a[AM
public int getCountId(){ i`r`Fj}-S-
return countId; W?.469yy
} 3U{
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} aM;SE9/U
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CountCache.java S=!WFKcJR
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/* 3u/JcU-<
* CountCache.java )/;+aDk
* :.e'?a
* Created on 2007年1月1日, 下午5:01 ?o;ip
* hFi gY\$m
* To change this template, choose Tools | Options and locate the template under [8sYE h
* the Source Creation and Management node. Right-click the template and choose ,X^3.ILz
* Open. You can then make changes to the template in the Source Editor. JfN
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*/ : x&R'wX-
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package com.tot.count; $kTm"I
import java.util.*; u_^mN9h
/** 8c)GUx
*
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* @author l'EO@D/M
*/ HfVHjF)
public class CountCache { A,<5W }
public static LinkedList list=new LinkedList(); . fja;aG
/** Creates a new instance of CountCache */ -a)1L'R
public CountCache() {} 3)EJws!
public static void add(CountBean cb){ qKfUm:7Q_
if(cb!=null){ wkx9@?2*
list.add(cb); l!x+K&
} B.r^'>jQ
} ,yltt+e
} ~-A"j\gi"
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CountControl.java x*vD^1"'P
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/* PG63{
* CountThread.java Q&]|W
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* /Yy)=~t{
* Created on 2007年1月1日, 下午4:57 7?whxi Qs
* 5VTVx1P[8
* To change this template, choose Tools | Options and locate the template under =l43RawAmu
* the Source Creation and Management node. Right-click the template and choose l{dsm1#W~
* Open. You can then make changes to the template in the Source Editor. ; R+>}6
*/ 2]mV9B
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package com.tot.count; 6AJk6W^Z
import tot.db.DBUtils; wI|h9q1U
import java.sql.*; .b]sQ'
/** JI.=y5I
* Q<V(#)*
* @author (s;W>,~q
*/ AaYH(2m-
public class CountControl{
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private static long lastExecuteTime=0;//上次更新时间 ^ 0YQlT98
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 -r sbSt ?_
/** Creates a new instance of CountThread */ wmGcXBHt$
public CountControl() {} ,N(Yjq"R
public synchronized void executeUpdate(){ Li6|c*K'
Connection conn=null; (U&
PreparedStatement ps=null; V gMgeja
try{ pZ>yBY?R8>
conn = DBUtils.getConnection(); **h4M2'C
conn.setAutoCommit(false); q|<B9Jk
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); a|z-EKV
for(int i=0;i<CountCache.list.size();i++){ /3aW 0/^o
CountBean cb=(CountBean)CountCache.list.getFirst(); Z>`\$1CI
CountCache.list.removeFirst(); BjfVNF;hk:
ps.setInt(1, cb.getCountId()); *Mhirz%iD
ps.executeUpdate();⑴ + kMj|()>\
//ps.addBatch();⑵ V,rc&97
} 8Ij<t{Lps
//int [] counts = ps.executeBatch();⑶ @[J6JT*E
conn.commit(); o>8~rtl
}catch(Exception e){ .+1I>L
e.printStackTrace(); T]wI)
} finally{ 62HA[cr&)
try{ YAc:QVT87
if(ps!=null) { X\Bl?
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ps.clearParameters(); jcqUY+T$
ps.close(); aPelt`
ps=null; >}* W$i
} <u\Hy0g
}catch(SQLException e){} xJ$uoy3+
DBUtils.closeConnection(conn); /iO"4%v
} A8&@Vxdz
} +H3~Infr4f
public long getLast(){ O z0-cM8t
return lastExecuteTime; Sn*s@RE\s
} ooJxE\L
public void run(){ eV*QUjS~
long now = System.currentTimeMillis(); 67rY+u%
if ((now - lastExecuteTime) > executeSep) { <CVX[R]U
//System.out.print("lastExecuteTime:"+lastExecuteTime); Jt5V{9:('
//System.out.print(" now:"+now+"\n"); `e,}7zGR
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); p"hO6b%V
lastExecuteTime=now; 90}vFoy
executeUpdate(); &)k=ccm
} w3(G!:
else{ hOB<6Tm[
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 3q/Us0jr
} fsjLD|?|:
} {nmu(EP
} V|
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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 _\d|`3RM
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类写好了,下面是在JSP中如下调用。 ywp_,j9F
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<% t/t6o&
CountBean cb=new CountBean(); bWA_a]G
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); @2"3RmYLo
CountCache.add(cb); q+9^rQ
out.print(CountCache.list.size()+"<br>"); FL \pgbI
CountControl c=new CountControl(); fC'u-m?!Q'
c.run(); 4|_xz;i
out.print(CountCache.list.size()+"<br>"); ^4`x:6m
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