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: U)&H.^@r$
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CountBean.java jEC'l]l
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/* ui s:\Uc
* CountData.java },?-$eyX
* 7H8GkuO
* Created on 2007年1月1日, 下午4:44 44Seq
* Y!K^-Y}
* To change this template, choose Tools | Options and locate the template under 9+WY@du+
* the Source Creation and Management node. Right-click the template and choose *Y|lO
* Open. You can then make changes to the template in the Source Editor. Bbn832iMUY
*/ #o(?g-3
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package com.tot.count; h$#4ebp
*#X+Gngo
/** I v 80,hW
* F9>(W#aC
* @author lW{I`r\]
*/ |q1b8A \
public class CountBean { Y{x[N}h
private String countType; *@b~f&Lx6
int countId; hW*^1%1
/** Creates a new instance of CountData */ bTA14&&q
public CountBean() {} Jgi{7J
public void setCountType(String countTypes){ Z7K!"I
this.countType=countTypes; ^*$WZMMJ1
} NKIk d
public void setCountId(int countIds){ 'ugR!o1
this.countId=countIds; S4@117z5
} ~|$) 1
public String getCountType(){ MSxU>FX0
return countType; xc3Ov9`8%
} %j
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public int getCountId(){ 7;$L&X
return countId; bUipp\[aV
} VC_3 ll]vr
} XY$cx~
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CountCache.java #/&q
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/* Z.cG`Km*
* CountCache.java 3!ajvSOI9j
* 93zlfLS0
* Created on 2007年1月1日, 下午5:01 DI2S
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* IArpCF/"8
* To change this template, choose Tools | Options and locate the template under O(c4iWm
* the Source Creation and Management node. Right-click the template and choose v]d?6g
* Open. You can then make changes to the template in the Source Editor. I%VV4,I&pK
*/ b{yH4)O
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package com.tot.count; N?`GZ+5
import java.util.*; R[ +]d|L
/** MOH,'@&6^
* T8M[eSbZ
* @author 5BGv^Qb_2
*/ <try%p|f
public class CountCache { /ab K/8ZQ
public static LinkedList list=new LinkedList(); =:0IHyB#0
/** Creates a new instance of CountCache */ ej??j<]
public CountCache() {} $yxIE}
public static void add(CountBean cb){ CO6XIgTe
if(cb!=null){ zL[U;
list.add(cb); plz=G}Y
} U`vt/#j
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} }gi`?58J6
} ^HU=E@
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CountControl.java
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/* KlSY^(kHR
* CountThread.java swe8
* @%5F^Vbd
* Created on 2007年1月1日, 下午4:57 @)M.u3{\
* )9;kzp/
* To change this template, choose Tools | Options and locate the template under X~/9Vd g
* the Source Creation and Management node. Right-click the template and choose YRT}fd>R&
* Open. You can then make changes to the template in the Source Editor. [;kj,j
*/ !UPAEA
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package com.tot.count; 5Dh&ez`oR'
import tot.db.DBUtils; nG(|7x
import java.sql.*; Xb07 l3UG
/** R}=]UOqH-
* m<VL19o>R
* @author KcMzZ!d7m
*/ Lh5+fk~i~8
public class CountControl{ RAXJsF^5o
private static long lastExecuteTime=0;//上次更新时间 qgY(S}V
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 RWEgUDX^/
/** Creates a new instance of CountThread */ lf7H8k, -
public CountControl() {} W0C$*oe!_i
public synchronized void executeUpdate(){ tI(t%~>^
Connection conn=null; &opH\wa
PreparedStatement ps=null; Yh!\:9@(
try{ uma9yIk
conn = DBUtils.getConnection(); F\$}8,9
conn.setAutoCommit(false); C8%nBa/
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); rt4|GVa
for(int i=0;i<CountCache.list.size();i++){ ^c:eXoU
CountBean cb=(CountBean)CountCache.list.getFirst(); l.t. ,:
CountCache.list.removeFirst(); 5Qe}v
ps.setInt(1, cb.getCountId());
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ps.executeUpdate();⑴ =F;^^VX
//ps.addBatch();⑵ 7[ VCCI
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} !&<Wc^PG
//int [] counts = ps.executeBatch();⑶ F^[Rwzv>c
conn.commit(); ?2
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}catch(Exception e){ J5r
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e.printStackTrace(); U1@P/
} finally{ OTr!?xi
try{ 085 ^!AZ
if(ps!=null) { m~\m"zJ4
ps.clearParameters(); Uu<sntyv
ps.close(); b9!J}hto,
ps=null; #p^pvdvh3
} RI].LB_
}catch(SQLException e){} Tr+Y@]"
DBUtils.closeConnection(conn); os0"haOI9h
} ,@j&q
} ), x3tTR
public long getLast(){ 1</t #r
return lastExecuteTime; Zi '8~iEH
} P<w>1
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public void run(){ q.Aw!]:!
long now = System.currentTimeMillis(); &qj&WfrB,
if ((now - lastExecuteTime) > executeSep) { E!]rh,mYK
//System.out.print("lastExecuteTime:"+lastExecuteTime); :j!_XMyT:
//System.out.print(" now:"+now+"\n"); wz2)seZY
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); Lzb [%?
lastExecuteTime=now; So0,)
executeUpdate(); W!Os ci
} kO O~%|1CP
else{ SX<>6vH&
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); N,'qMoNf
} (]uoN4
} 7*W$GCd8
} SX94,5 _Q
//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 Pxuz {
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类写好了,下面是在JSP中如下调用。 hB1 iSm
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<% \y+F!;IxL
CountBean cb=new CountBean(); BB}iBf I'
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); EwJn1Mvq
CountCache.add(cb); ;
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out.print(CountCache.list.size()+"<br>"); }z%/6`7)|
CountControl c=new CountControl(); TEy.zzt
c.run(); hQrsZv:Q
out.print(CountCache.list.size()+"<br>"); ]0nC;|]@Lx
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