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{ Dr
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CountBean.java +]uy
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/* 8"oS1W
* CountData.java px4Z
* K/MIDH
* Created on 2007年1月1日, 下午4:44 S`0@fieOf
* jq.@<<j|$
* To change this template, choose Tools | Options and locate the template under ,e.y4
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* the Source Creation and Management node. Right-click the template and choose N:L<ySJ7
* Open. You can then make changes to the template in the Source Editor. eDaVoc3
*/ $23="Jcl
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package com.tot.count; ~JC``&6E=}
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/** ik&loM_
* ,Oxdqx u7
* @author -.^Mt.)
*/ %NeKDE
public class CountBean { m?[F)<~a
private String countType; t$\]6RU
int countId; O,^,G<`
/** Creates a new instance of CountData */ >IoOCQQ*
public CountBean() {} !m_'<=)B4~
public void setCountType(String countTypes){ $9W9* WQL
this.countType=countTypes; j{p0yuZ)<
} ).v;~yE
public void setCountId(int countIds){ !vImmhI!I
this.countId=countIds; D#(A?oN
} e#_xDR:
public String getCountType(){ Bc t>EWQ
return countType; v`wPdb
} )j6S<mn
public int getCountId(){ K<s\:$VVh
return countId; ^gb2=gWZ<
} HO' ELiZ_q
} :dLS+cTC
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CountCache.java I9Z8]Q+2"
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/* rTmcP23]
* CountCache.java l l&iMj]
*
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* Created on 2007年1月1日, 下午5:01 h!d#=.R
* _e`b^_
* To change this template, choose Tools | Options and locate the template under 0CTI=<;
* the Source Creation and Management node. Right-click the template and choose DCwldkdJN
* Open. You can then make changes to the template in the Source Editor. VaX>tUW
*/ c?IIaj!
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package com.tot.count; ty-4yK#
import java.util.*; [fO]oTh
/** W>B:W 0A
* =q6yb@
* @author s[xdID^3.
*/ Bb-x1{t
public class CountCache { 7Kh+m@q.
public static LinkedList list=new LinkedList(); tM@TT@.t~
/** Creates a new instance of CountCache */ + FLzK(
public CountCache() {} N4H nW0
public static void add(CountBean cb){ q=96Ci _a
if(cb!=null){ Zqx5I~
list.add(cb); 61gZZM
} V]vk9M2q[l
} kP[ Y
} Q^mJ _~
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CountControl.java QV?\?9(
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/* 0'L+9T5
* CountThread.java i(U*<1y
* CrqWlO
* Created on 2007年1月1日, 下午4:57 Dj<Vn%d*
* 7&T1RB'>
* To change this template, choose Tools | Options and locate the template under D, 3x:nK
* the Source Creation and Management node. Right-click the template and choose Y9PG
* Open. You can then make changes to the template in the Source Editor. (_-zm)F7
*/ z`
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package com.tot.count; T_\GvSOI
import tot.db.DBUtils; .^Ek1fi.
import java.sql.*; nnr(\r~
/** |@d7o]eM|
* <PfW
* @author YpNTq_S1,
*/ IClnh1=
public class CountControl{ 8c~b7F
\
private static long lastExecuteTime=0;//上次更新时间 ~G"6^C:x
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Kq.)5%~>
/** Creates a new instance of CountThread */ RJd55+h
public CountControl() {} d]a*)m&
public synchronized void executeUpdate(){ g{a_{P
Connection conn=null; \idg[&}l}
PreparedStatement ps=null; le8n!Dk(
try{ \W*ouH
conn = DBUtils.getConnection(); {)k}dr
conn.setAutoCommit(false); [m('Y0fwO^
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); BQw#PXp3
for(int i=0;i<CountCache.list.size();i++){ HYpB]<F
CountBean cb=(CountBean)CountCache.list.getFirst(); 1[B?nk
CountCache.list.removeFirst(); UHR)]5Lt
ps.setInt(1, cb.getCountId()); }hl#
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ps.executeUpdate();⑴ !@*Ac$J>$
//ps.addBatch();⑵ fv`%w
} lDAw0 C3
//int [] counts = ps.executeBatch();⑶ dq|z;,`
conn.commit(); >B~p[wh0
}catch(Exception e){ ,gRsbC
e.printStackTrace(); WU}JArX9
} finally{ 2Uk$9s
try{ mtJI#P
if(ps!=null) { 5GpRN
ps.clearParameters(); ]A!Gr(FHQ
ps.close(); w"A'uFXLc
ps=null; #x"pG
} <$7*yV
}catch(SQLException e){} c
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DBUtils.closeConnection(conn); tJg
} IURi90Ir
} =DF7l<&km
public long getLast(){ t;E-9`N
return lastExecuteTime; Af *^u|#
} u^V`Ucd"R
public void run(){ qW7S<ouh
long now = System.currentTimeMillis(); @gs
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if ((now - lastExecuteTime) > executeSep) { sFB; /*C
//System.out.print("lastExecuteTime:"+lastExecuteTime); HM--`RJ
//System.out.print(" now:"+now+"\n"); $7PFos%@
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); f3*u_LO
lastExecuteTime=now; #msk'MVt
executeUpdate(); i}M&1E
} PVV \@
else{ i' N
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); z!t&zkAK
} n; !t?jnf.
} #nn2odR
} |4wVWJ7
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 }4ta#T Ea
| F:?
类写好了,下面是在JSP中如下调用。 )S>~ h;
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<% _RjM .
CountBean cb=new CountBean(); [}d
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); I_Oa<J\+
CountCache.add(cb); !y?g$e`
out.print(CountCache.list.size()+"<br>"); A^o
CountControl c=new CountControl(); :9K5zD
c.run(); *gZ4Ub|O
out.print(CountCache.list.size()+"<br>"); o),i2
%>