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: L}\~)
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CountBean.java g<PglRr"
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/* s|d"2w6t
* CountData.java vmIt!x
* Rxk0^d:sNi
* Created on 2007年1月1日, 下午4:44 i;mA|
* H?tX^HO:q
* To change this template, choose Tools | Options and locate the template under l{4rKqtX
* the Source Creation and Management node. Right-click the template and choose )k6kK}
* Open. You can then make changes to the template in the Source Editor. 'O[0oi&
*/ h#(J6ht
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package com.tot.count; 8KHT"uc'*J
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/** @t4OpU<'*b
* C9L_`[9DO
* @author !i5~>p|4@
*/ MyaJhA6c
public class CountBean { V3c7F4\
private String countType; OS sYmF
int countId; DZqY=Sze
/** Creates a new instance of CountData */ vfloha p
public CountBean() {} pgEDh^[MW
public void setCountType(String countTypes){ NGVl/Qd
this.countType=countTypes; VQl(5\6O
} ,'&H`h54
public void setCountId(int countIds){ JUdQ Q
this.countId=countIds; y87oW_"h
} xj;V
public String getCountType(){ OmLe+,7'
return countType; *:V+whBY
} Z,7VOf6g
public int getCountId(){ 12HE=
return countId; <P.'r,"[
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} 'mO>hD`V
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CountCache.java Js/QL=,
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/* "WZ |
* CountCache.java Hp5.jor(k
* 3oBR
* Created on 2007年1月1日, 下午5:01 {.o@XP,.
* 3{9d5p|\i
* To change this template, choose Tools | Options and locate the template under t$g@+1p4
* the Source Creation and Management node. Right-click the template and choose 3 @%XR8ss
* Open. You can then make changes to the template in the Source Editor. <d~si^*\ch
*/ ?tx."MZ
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package com.tot.count;
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import java.util.*; '^%k TNn
/** ,)ZI&BL5
* r1/9BTPKdJ
* @author JsHD3
*/ hO; XJyv
public class CountCache { &gsBbQ+qA
public static LinkedList list=new LinkedList(); T(
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/** Creates a new instance of CountCache */ ~|( eh9
public CountCache() {} FwUgMR*xq
public static void add(CountBean cb){ `T3B
if(cb!=null){ #*X\pjZ
list.add(cb); Eo>EK>
} v-DZW,
} Fs&r^ [/b
} t ^~Qv
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CountControl.java d
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/* OXI>`$we
* CountThread.java ;b!qt-;.<
* p v]" 2'aQ
* Created on 2007年1月1日, 下午4:57 # p2`9o
* *" +u^
* To change this template, choose Tools | Options and locate the template under ZQ{-6VCjl
* the Source Creation and Management node. Right-click the template and choose {A'_5 X9
* Open. You can then make changes to the template in the Source Editor. iTVZo?lVo
*/ T{)_vQ
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package com.tot.count; (D0\uld9
import tot.db.DBUtils; tE,&
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import java.sql.*; EYA=fU
/** '}$$0S.DC
* 8p]9A,Uq&
* @author 9;NXzO27
*/ 0ZJj5<U
public class CountControl{ ($-m}UF\/
private static long lastExecuteTime=0;//上次更新时间 2P ^x'I
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 iFnD`l6)
/** Creates a new instance of CountThread */ BhhFij4
public CountControl() {} xZA.<Yd^r
public synchronized void executeUpdate(){ 1Eb2X}XC
Connection conn=null; b8E7/~<z3
PreparedStatement ps=null; Bk[C=< X
try{ 0+e
conn = DBUtils.getConnection(); e,
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conn.setAutoCommit(false); sLUOs]cj
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); +t3o5&
for(int i=0;i<CountCache.list.size();i++){ ~*x 2IPiH
CountBean cb=(CountBean)CountCache.list.getFirst(); 1!NrndJ I
CountCache.list.removeFirst(); }=Ul8
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ps.setInt(1, cb.getCountId()); .wB'"z8L
ps.executeUpdate();⑴ gloJ;dEB
//ps.addBatch();⑵ KwU;+=_.
} aa"3
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//int [] counts = ps.executeBatch();⑶ ;GIA`=a%
conn.commit(); nc6PSj X
}catch(Exception e){ 8OiCldw:HN
e.printStackTrace(); S%aup(wu6
} finally{ 51Vqbtj^
try{ "6
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if(ps!=null) { ~r~YR=
ps.clearParameters(); yD#(Iw
ps.close(); `x_}mdR
ps=null; uVTacN%X
} PQp/&D4K
}catch(SQLException e){} 0TZB}c#qT
DBUtils.closeConnection(conn); sUU[QP-
} .N( X.C
} `]^W#6l
public long getLast(){ n'0r
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return lastExecuteTime; > l]Ble
} Ft?eqDS1
public void run(){ V>/,&~0
long now = System.currentTimeMillis(); vn!5@""T
if ((now - lastExecuteTime) > executeSep) { hQ'W7EF
//System.out.print("lastExecuteTime:"+lastExecuteTime); p6V#!5Q
//System.out.print(" now:"+now+"\n"); ~6IY4']m*
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ;wkMa;%`g|
lastExecuteTime=now; k7j.VpN9
executeUpdate(); %-a;HGbZn
} `mA;1S
else{ ]6M,s0
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); @yo6w}3+-
} 4EmdQn
} zc$}4o
} N`?|~g3
//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 AUu<@4R7
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类写好了,下面是在JSP中如下调用。 Q6D>(H#"0
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<% {2YqEX-I*
CountBean cb=new CountBean(); %}e['d h
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); r8?p6E
CountCache.add(cb); 1wFW&|>1
out.print(CountCache.list.size()+"<br>"); #:By/9}-
CountControl c=new CountControl(); V:>r6
c.run(); 0N~kq-6.\
out.print(CountCache.list.size()+"<br>"); YC')vv3o(
%>