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: _&)^a)Nu
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CountBean.java :>4pH
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/* .<7M4Z
* CountData.java
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* NbgK#;
* Created on 2007年1月1日, 下午4:44 ]^j:}#R
* H3\4&q
* To change this template, choose Tools | Options and locate the template under g@0<`g
* the Source Creation and Management node. Right-click the template and choose :0@R(ct;>
* Open. You can then make changes to the template in the Source Editor. (#I$4Px{
*/ WzG]9$v &
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package com.tot.count; g~EN3~
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/** &CBW>*B
* H4RqOI
* @author O?\UPNb:K
*/ RN:VsopL
public class CountBean { vd<r}3i*
private String countType; dpAj9CX(
int countId; OM,Dy&Y
/** Creates a new instance of CountData */ VWhq+8z
public CountBean() {} <"/b 5kc
public void setCountType(String countTypes){ cPaz-
this.countType=countTypes; @}9*rWJIE
} &[
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public void setCountId(int countIds){ , e^&,5b
this.countId=countIds; hc7"0mVd{
} hA=.${uIO
public String getCountType(){ ;OC~,?O5
return countType; /Ne;Kdp
} $-^
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public int getCountId(){ 1fgO3N
return countId; OVq(ulwi+
} %u=b_4K"j
} O q3aboAt
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CountCache.java ,c]<Yu
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/* vw~=z6Ka
* CountCache.java ?uAq goCl
* `@<>"ff#F
* Created on 2007年1月1日, 下午5:01 gn-@OmIs
* ]g] ]\hS
* To change this template, choose Tools | Options and locate the template under $sILCn
* the Source Creation and Management node. Right-click the template and choose F)8M9%g5m
* Open. You can then make changes to the template in the Source Editor. =w !>/#U
*/ >DM^/EAG{
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package com.tot.count; oaac.7.fV
import java.util.*; }[;{@Zn
/** ,vDSY N6
* $G<!+^T
* @author ;9MIapfUd(
*/ !8Y$}
public class CountCache { *lo0T93B
public static LinkedList list=new LinkedList(); QZwZ4$jkiO
/** Creates a new instance of CountCache */ fphi['X
public CountCache() {} dDrzO*a\
public static void add(CountBean cb){ Mg~62u
if(cb!=null){ r }S>t~p:
list.add(cb); $V870
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} SX)o0v+
} mI>=S
} 9Zj9e
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CountControl.java pqF!1
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/* STjk<DP(
* CountThread.java ugV/#v O
* d-{1>\-_
* Created on 2007年1月1日, 下午4:57 6s.>5}M!
* _aP2gH
* To change this template, choose Tools | Options and locate the template under f0@4>\g
* the Source Creation and Management node. Right-click the template and choose 0'Uo3jAB
* Open. You can then make changes to the template in the Source Editor. AfT;IG%Gt
*/ 4+B&/}FDLo
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package com.tot.count; <4:%M
import tot.db.DBUtils; Gd Vrl[
import java.sql.*; (zml704dI)
/** LjySO2
* 06]%$-j
* @author R ~? 9+
*/ o`M.v[O
public class CountControl{ ^wlo;.8Y
private static long lastExecuteTime=0;//上次更新时间 Z,I0<ecaD
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 HSj=g}r
/** Creates a new instance of CountThread */ @[v4[yq-
public CountControl() {} ja&S^B^@
public synchronized void executeUpdate(){ #i 5@G*
Connection conn=null; \C kb:
PreparedStatement ps=null; 9jI5bi)
try{ GK&R,q5}
conn = DBUtils.getConnection(); 5 \iX%w@
conn.setAutoCommit(false); gxc8O).5vY
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); R*O<(
for(int i=0;i<CountCache.list.size();i++){ UT%?3}*u"
CountBean cb=(CountBean)CountCache.list.getFirst(); p5Wz.n.<'
CountCache.list.removeFirst(); }u.I%{4
ps.setInt(1, cb.getCountId()); (R]b'3,E$
ps.executeUpdate();⑴ =sUrSVUeU
//ps.addBatch();⑵ ipD/dx.
} XP(fWRT1
//int [] counts = ps.executeBatch();⑶ >Yx,%a@~R
conn.commit(); :Izdj*HL;A
}catch(Exception e){ (9KiIRN
e.printStackTrace(); i4\DSQJ
} finally{ i#%!J:_=
try{ X\1.,]O >
if(ps!=null) { ,.i)(Or
ps.clearParameters(); ebiOR1)sN
ps.close(); ,&LGAa
ps=null; RA*W Ys&xb
} _i2guhRs*Q
}catch(SQLException e){} X< 4f7;]O
DBUtils.closeConnection(conn); _ykT(`.#
} %
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} C/ENJ&
public long getLast(){ >k8FUf(c
return lastExecuteTime; IN?rPdY
} bE1@RL
public void run(){ <P_B|Y4N/
long now = System.currentTimeMillis(); ^oDSU7j5,
if ((now - lastExecuteTime) > executeSep) { m^KK
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//System.out.print("lastExecuteTime:"+lastExecuteTime); \@$V^;OP/
//System.out.print(" now:"+now+"\n"); I`q"
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); vt(cC))
lastExecuteTime=now; Id=g!L|
executeUpdate(); y\mK?eR
} w">-r}HnJ
else{ #T08H,W/
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); .-}F~FES
} 7 ;SI=
} <nJ8%aY,
} @QAI 0ZY
//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 =-;J2Qlg6
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类写好了,下面是在JSP中如下调用。 c}mWAZ=wF
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<% '\R/-.
CountBean cb=new CountBean(); 3?s1Yw>?
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); b2XUZ5
CountCache.add(cb); q]wP^;\Jl
out.print(CountCache.list.size()+"<br>"); v|wO qS
CountControl c=new CountControl(); "U*6?]f
c.run(); @WICAC=
out.print(CountCache.list.size()+"<br>"); z<,-:=BC"
%>