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: "d}ey=$h4
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CountBean.java ^7;s4q
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/* EUV8H}d5
* CountData.java %S$$*|_G
* })J}7@VPO
* Created on 2007年1月1日, 下午4:44 # Oq.}x?i
* ?FR-aXx
* To change this template, choose Tools | Options and locate the template under +.|RH
* the Source Creation and Management node. Right-click the template and choose S9%,{y
* Open. You can then make changes to the template in the Source Editor. pDvznpQ
*/ AA=eWg
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package com.tot.count; |~18MW
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/** zE/\2F$
* 8`]yp7ueS
* @author ]0|A\bE\S
*/ puMbB9)
public class CountBean { zf^|H%
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private String countType; /Ah&d@b
int countId; KU]o=\ak%
/** Creates a new instance of CountData */ DrxQ(yo}
public CountBean() {} yg~@}_C2_
public void setCountType(String countTypes){ ~ ^
this.countType=countTypes; [/n@BK
} A%^7D.j
public void setCountId(int countIds){ @tD (<*f+
this.countId=countIds; m_`%#$s}
} >&7^yXS
public String getCountType(){ kl9~obX
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return countType; _./s[{ek
} `c-omNu
public int getCountId(){ a1_ o
return countId; P$*Ngt
} Sw5-^2x0'
} B_b5&M@
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CountCache.java (-&d0a9N
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/* Y}<%~z#.4
* CountCache.java MPw?HpM
* _jgtZ
* Created on 2007年1月1日, 下午5:01 ``6-
* Nv6"c<(L=
* To change this template, choose Tools | Options and locate the template under wArfnB&
* the Source Creation and Management node. Right-click the template and choose 6f
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* Open. You can then make changes to the template in the Source Editor. b>k2@
*/ e6jA4X+a
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package com.tot.count; rK:cUW0]X
import java.util.*; y=EVpd
/** pv-c>8Wb6
* jh`[Y7RJO
* @author rzLW@k
*/ zEukEA^9`
public class CountCache { N>]J$[j
public static LinkedList list=new LinkedList(); f:J-X~T_f
/** Creates a new instance of CountCache */ ^M;#x$Y?
public CountCache() {} #h4FLF_w
public static void add(CountBean cb){ BNI)y@E^X
if(cb!=null){ :g^
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list.add(cb); WY!4^<|w"
} f#w
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} Z,Us<du
} 4i^WE;|s
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CountControl.java u|.7w2
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/* SO[ u4b_"h
* CountThread.java xk7Dx}
* k6RVP:V
* Created on 2007年1月1日, 下午4:57 &;L=f;
* & 0WQF
* To change this template, choose Tools | Options and locate the template under V'MY+#
* the Source Creation and Management node. Right-click the template and choose ['sNk[-C
* Open. You can then make changes to the template in the Source Editor. _nxH;Za
*/ T&b_*)=S
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package com.tot.count; 5$cjCjY
import tot.db.DBUtils; w-LENdw
import java.sql.*; /wt7KL-I
/** 57gt"f
* 4K?
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* @author c:>&YGmhu
*/ V %D1Q}X
public class CountControl{ 32%Fdz1S
private static long lastExecuteTime=0;//上次更新时间 *h3iAcM8
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ?h%Jb^#9
/** Creates a new instance of CountThread */ 150-'Q
public CountControl() {} N
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public synchronized void executeUpdate(){ ~T-uk
Connection conn=null; e6J^J&`|4
PreparedStatement ps=null; 7Zdg314
try{ G
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conn = DBUtils.getConnection(); UOl*wvy
conn.setAutoCommit(false); n_9Ex&?e
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); E]GbLU;TH
for(int i=0;i<CountCache.list.size();i++){ A~<!@`NjB
CountBean cb=(CountBean)CountCache.list.getFirst(); f% )9!qeW
CountCache.list.removeFirst(); BK6
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ps.setInt(1, cb.getCountId()); 5\#I4\
ps.executeUpdate();⑴ ~QxW^DGa7]
//ps.addBatch();⑵ B%MdJD>
} _6ck@
//int [] counts = ps.executeBatch();⑶ c1jRj=\
conn.commit(); LCtVM70
}catch(Exception e){ _N^w5EBC]
e.printStackTrace(); &r4|WM/ec
} finally{ s*<T'0&w0S
try{ ::$W
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if(ps!=null) { Y_!+Y<x7v
ps.clearParameters(); U&Vu%+B
ps.close(); rVl 8?uy
ps=null; fi%i
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} 3Ke6lV)uq
}catch(SQLException e){} <p*k-mfr
DBUtils.closeConnection(conn); 7*KUM6z
} o.0tD
} \U>&W
public long getLast(){ VwPoQ9pIS
return lastExecuteTime; T]-MrnO
} [xr^t1
public void run(){ 09jE7g @X}
long now = System.currentTimeMillis(); }l[e@6r F
if ((now - lastExecuteTime) > executeSep) { U$& '> %#
//System.out.print("lastExecuteTime:"+lastExecuteTime); >Bf3X&uS
//System.out.print(" now:"+now+"\n"); 2%`=
LGQC
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); +,LWyvc'
lastExecuteTime=now; 4_U"M@
executeUpdate(); vszm9Qf
} gK({InOP
else{ KU9FHN
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); YI,t{Wy
} tzIP4CR~F&
} 111A e*U
} p'2IlQ\
//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 9*ZlNZ
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类写好了,下面是在JSP中如下调用。 E1OrL.A6
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<% ;<m`mb4x[
CountBean cb=new CountBean(); /r"<:+
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Hcu!bOQ
CountCache.add(cb); D_czUM
out.print(CountCache.list.size()+"<br>"); _OuNX.yrG
CountControl c=new CountControl(); M.- {->
c.run(); ~h;
out.print(CountCache.list.size()+"<br>"); 4d PTrBQ?
%>