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: T~0k"uTE
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CountBean.java u&mS8i}
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/* anMF-x4/*q
* CountData.java R_XR4)(<
* H,nec<Jp
* Created on 2007年1月1日, 下午4:44 o%9*B%HO/
* {(U %i\F\
* To change this template, choose Tools | Options and locate the template under {!t7[Ctb
* the Source Creation and Management node. Right-click the template and choose eq(am%3~
* Open. You can then make changes to the template in the Source Editor. fk1ASV<rN
*/ ojvj}ln
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package com.tot.count; I M-L'9
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/** Szbb_i{_
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* }J">}j]/
* @author TJ q~)Bm
*/ +t5U.No
public class CountBean { >Cw<BIF
private String countType; VCXJwVb
int countId; ;s`sn$@
/** Creates a new instance of CountData */
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public CountBean() {} pn.wud}R
public void setCountType(String countTypes){ q\m2EURco
this.countType=countTypes; $,+O9Et
} x8S7oO7
public void setCountId(int countIds){ -gSUjP
this.countId=countIds; 'EDda
} h$4Hw+Yxs]
public String getCountType(){ h%}/Cmx[
return countType;
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} sl]_M
public int getCountId(){ R"
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return countId; n a9sm
} ]gYz
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} ~0beuK&p
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CountCache.java K+;e4_\
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/* 0 stc9_O
* CountCache.java 9E>xIJ@J2T
* |B?27PD
* Created on 2007年1月1日, 下午5:01 Re P|UH
* X!e[GJ
* To change this template, choose Tools | Options and locate the template under $5Xh,DOg
* the Source Creation and Management node. Right-click the template and choose #Q2Y&2`yGT
* Open. You can then make changes to the template in the Source Editor. Y.g59X!Ub2
*/ J]nohICe
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package com.tot.count; cWoPB
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import java.util.*; \v'p/G)g
/** !%"8|)CAr
* "jG}B.l=,
* @author G6T_O
*/ xuqv6b.
public class CountCache { a)wJT`xu
public static LinkedList list=new LinkedList(); ,%uo6%
/** Creates a new instance of CountCache */ ee yHy"@
public CountCache() {} 1oc3$A
public static void add(CountBean cb){ |&RU/ a
if(cb!=null){ N<~t3/Nm
list.add(cb); 28 ?\
} &l!4mxwr`
} <YdE1{fm
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CountControl.java ~`aa5;Ab_
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/* :Zlwp6
* CountThread.java ;M)QwF1
* z6*X%6,8
* Created on 2007年1月1日, 下午4:57 N@t|7~
* FoN|i"*l
* To change this template, choose Tools | Options and locate the template under ;lHr =e7
* the Source Creation and Management node. Right-click the template and choose R}O_[
* Open. You can then make changes to the template in the Source Editor. $<}$DH_Y
*/ tfj:@Z5&$C
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package com.tot.count; &J+CSv,39
import tot.db.DBUtils; wne,e's}
import java.sql.*; LDPUD'
/** `aciXlqIF
* Lm%:K]X
* @author '<"s \,
*/ G3Z)Z)N
public class CountControl{ %J+E/
private static long lastExecuteTime=0;//上次更新时间 KrQ1GepJ
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 #1OOU
/** Creates a new instance of CountThread */ SLa>7`<Q
public CountControl() {} <g$~1fa
public synchronized void executeUpdate(){ U|jSa,}
Connection conn=null; ;U-jO &
PreparedStatement ps=null; %nf6%@s
try{ 1`=nWy='
conn = DBUtils.getConnection(); k$blEa4
conn.setAutoCommit(false); Ff)8Q.m
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); i<#QW'R (
for(int i=0;i<CountCache.list.size();i++){ .%xn&3
CountBean cb=(CountBean)CountCache.list.getFirst(); A1O'|7X
CountCache.list.removeFirst(); MN\HDKN
ps.setInt(1, cb.getCountId()); >T^;MS
ps.executeUpdate();⑴ =l+yA>t|
//ps.addBatch();⑵ [_k1jHr48N
} pH9VTM.*
//int [] counts = ps.executeBatch();⑶ \NPmym_6J
conn.commit(); .P8&5i)'P,
}catch(Exception e){ T;r2.Pupn
e.printStackTrace(); !LNayk's>
} finally{ +S o4rA*9
try{ Ayxkv)%:@)
if(ps!=null) { uXn1
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ps.clearParameters(); uvkz'R=
ps.close(); c2l@6<Ww
ps=null; 0XE4<U
} eA2@Nkw~)
}catch(SQLException e){} %)1y AdG
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DBUtils.closeConnection(conn); CsGx@\jN
} >;e~ WF>+K
} Kp%2k^U
public long getLast(){ C5o#i*|
return lastExecuteTime; >qnko9 V
} wW>A_{Y
public void run(){ <^#,_o,!
long now = System.currentTimeMillis(); ;U/&I3dzV
if ((now - lastExecuteTime) > executeSep) { ag [ZW
//System.out.print("lastExecuteTime:"+lastExecuteTime);
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//System.out.print(" now:"+now+"\n"); =$'6(aDH
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); oB(?_No7
lastExecuteTime=now; c"f-3kFv
executeUpdate(); 6'k<+IR
} bRFLcM
else{ DhKS
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); ;`0%t$@-
} C0T;![/4A
} (KjoSN(
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} igCZ|Ru\
//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 W=N+VqK
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类写好了,下面是在JSP中如下调用。 rBQ _iB_
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<% }T(D7|^R
CountBean cb=new CountBean(); UXJeAE-
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); &*M!lxDN
CountCache.add(cb); "q3ZWNS'w
out.print(CountCache.list.size()+"<br>"); ` Fa~
CountControl c=new CountControl(); kMIcK4.MH
c.run(); 8V'~UzK
out.print(CountCache.list.size()+"<br>"); zu_8># i-
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