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: #w' kV#
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CountBean.java 0$ S8fF@
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/* `hQ5VJo
* CountData.java Fvbh\m
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* 4rLL[??
* Created on 2007年1月1日, 下午4:44 !6*"(
* S[J}UpV
* To change this template, choose Tools | Options and locate the template under <$IM8Y5p+w
* the Source Creation and Management node. Right-click the template and choose i%0ur}p
* Open. You can then make changes to the template in the Source Editor. :51/29}
*/ V6@o]*
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package com.tot.count; -w"VK|SGm
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/** ~5}*
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* De'_SD|=
* @author L6|oyf
*/ ^SF&=NpV
public class CountBean { ]SLP}Jwy
private String countType; w|K'M?N14
int countId; &7K?w~
/** Creates a new instance of CountData */ 8ap%?
public CountBean() {} KV0]m^@x
public void setCountType(String countTypes){
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this.countType=countTypes; xD~5UER
} YwjKAyLU
public void setCountId(int countIds){ J^Wa8Q;9lX
this.countId=countIds; [J?aD`{#O
} kY-N>E:
public String getCountType(){ Z/Dx,zIR
return countType; W*),y:
} n<z[J=I
public int getCountId(){ klT@cO-9
return countId; 3
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} %[ Z \S0C
} e?8FN. q
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CountCache.java pL/DZ|S3
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/* 7o#I,d~
* CountCache.java E/|To
* l3ko?k
* Created on 2007年1月1日, 下午5:01 -z)n?(pftm
* Z8K?
* To change this template, choose Tools | Options and locate the template under 42$VhdG
* the Source Creation and Management node. Right-click the template and choose -"'j7t:
* Open. You can then make changes to the template in the Source Editor. "&G/T ?4
*/ Ku5\]
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package com.tot.count; 128EPK
import java.util.*; i:Y^{\Z?V
/** +M\`#i\g>
* q_A!'sm@)
* @author 3TeY%5iVt
*/ vqDu(6!2
public class CountCache { su{poQ}K
public static LinkedList list=new LinkedList(); P3+5?.p.
/** Creates a new instance of CountCache */ 4%>$-($
public CountCache() {} s(/;U2"e
public static void add(CountBean cb){ ^/I
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if(cb!=null){ < $lCkSx<Q
list.add(cb); YNKHN2E8
} K*LlW@
} yerg=,$_i
} a|t$l=|DD
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CountControl.java 96( v
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/* L*xhGoC=
* CountThread.java ?PeJlpYzV
* s>7}zU]
* Created on 2007年1月1日, 下午4:57 S9]'?|
* vWzm@
* To change this template, choose Tools | Options and locate the template under ` Mjj@[
* the Source Creation and Management node. Right-click the template and choose *\+\5pu0
* Open. You can then make changes to the template in the Source Editor. PUp6Q;AdQ
*/ H<i]V9r
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package com.tot.count; jnO9j_CY
import tot.db.DBUtils; 6F!+T=
import java.sql.*; xpV|\2C
/** 4&<oFW\r
* i[7\[
* @author ^}/PGG\~r
*/ =Y{(%sn
public class CountControl{ <\rT%f}3^
private static long lastExecuteTime=0;//上次更新时间 UZ\u;/}
private static long executeSep=60000;//定义更新间隔时间,单位毫秒
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/** Creates a new instance of CountThread */ _|kxY'_[8
public CountControl() {} J=9FRC
public synchronized void executeUpdate(){ P{kur} T
Connection conn=null; /M1ob: m
PreparedStatement ps=null; ;DqWh0
try{ !;q&NHco
conn = DBUtils.getConnection(); `i3NG1
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conn.setAutoCommit(false); q9KHmhUD
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); XixL R
for(int i=0;i<CountCache.list.size();i++){ ?uzRhC_)!
CountBean cb=(CountBean)CountCache.list.getFirst(); Elcj tYu4
CountCache.list.removeFirst(); }7|1
ps.setInt(1, cb.getCountId()); Yb|c\[ %
ps.executeUpdate();⑴ 3`t#UY).F
//ps.addBatch();⑵ KrgFKRgGj
} eenH0Ovv
//int [] counts = ps.executeBatch();⑶ 7Wf/$vRab
conn.commit(); 4[m`#
}catch(Exception e){ {Z(h.de
e.printStackTrace(); V\ZG d+?
} finally{ UOv+T8f=
try{ !Q2d(H>
if(ps!=null) { XRM_x:+]
ps.clearParameters(); $v4.sl:x
ps.close(); ysQ_[
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ps=null; RIWxs Zt
} ugdQAg
}catch(SQLException e){} vOn`/5-
DBUtils.closeConnection(conn); 6a(yp3
} TV)h`\|Z*
} M'7f O3&|
public long getLast(){ M8MRoA6F
return lastExecuteTime; SE@LYeC}dE
} &47i"%
public void run(){ /?uPEKr
long now = System.currentTimeMillis(); >K_(J/&p
if ((now - lastExecuteTime) > executeSep) { [_R~%Yh+'E
//System.out.print("lastExecuteTime:"+lastExecuteTime); ,k +IPkN+
//System.out.print(" now:"+now+"\n"); CpUkCgg
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); o5Dk:Bw
lastExecuteTime=now; x[FJgI'r
executeUpdate(); lHN5Dr
} c,np2myd
else{ u@Ih GME
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); :KQ~Cb
} I:R[;TB?y
} ?ZV/U!y
} u1J0$
//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 Ec!"O3%!M^
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类写好了,下面是在JSP中如下调用。 RuLi,'u
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<% >{q]&}^U
CountBean cb=new CountBean(); C)um9}
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); [<lHCQXJ/
CountCache.add(cb); 5V?&8GTe
out.print(CountCache.list.size()+"<br>"); {%rA1g
CountControl c=new CountControl(); 0IsPIi"7
c.run(); B~1_ 28\
out.print(CountCache.list.size()+"<br>"); H4WP~(__
%>