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: D*_ F@}=
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CountBean.java =]"[?a >
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/* gl00$}C
* CountData.java _U'edK]R
* `s@1'IG;R_
* Created on 2007年1月1日, 下午4:44 qAkx52v6
* _es>G'S
* To change this template, choose Tools | Options and locate the template under Cf8(Jk`v|
* the Source Creation and Management node. Right-click the template and choose YW>|gE
* Open. You can then make changes to the template in the Source Editor. 4dl?US[-
*/ Jd/5Kx
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package com.tot.count; {hVSVx8ZL
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/** H| IsjCc
* rt t?4
* @author us$~6
*/ )FE'#\
public class CountBean { &\K,kS [.r
private String countType; ]+ug:E{7
int countId; F;`es%8
/** Creates a new instance of CountData */ )p ,-TtV
public CountBean() {} u{exQ[,E
public void setCountType(String countTypes){ hnH:G`[F
this.countType=countTypes; hg=\L5R
} _d)w, ;m#
public void setCountId(int countIds){ O^|,Cbon6
this.countId=countIds; 0jE,=<W0>
} pcm|
public String getCountType(){ !0E$9Xon
return countType; H`B%6S/
} Zb8i[1 P
public int getCountId(){ `d8}3D
return countId; <S TwylL
} JA())0a
} V/J[~mN9
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CountCache.java ]TqcV8Q~
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/* %%klR{
* CountCache.java 2>?GD@GE
* Vs\)w>JF
* Created on 2007年1月1日, 下午5:01 B8;_h#^q
* 1rTA0+h
* To change this template, choose Tools | Options and locate the template under <)y'Ot0 y
* the Source Creation and Management node. Right-click the template and choose z{;W$SO
2
* Open. You can then make changes to the template in the Source Editor. O:pQf/Xn
*/ nvgo6*
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package com.tot.count; H~@aT7
import java.util.*; < _c84,[V
/** 6'|J
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* ';zLh
* @author ?Q:se
*/ /vSFQ}W
public class CountCache { vqv(KsD+::
public static LinkedList list=new LinkedList(); >PL/>
/** Creates a new instance of CountCache */ |M0 XLCNd_
public CountCache() {} goWD~'\
public static void add(CountBean cb){ RhX
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if(cb!=null){ TDy@Y>
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list.add(cb); dax|4R
} eAm7*2
} &Lk@Xq1
} e Hd{'J<
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CountControl.java />.&
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/* st/Tb/
* CountThread.java f}nGWV%,
* W >;AMun
* Created on 2007年1月1日, 下午4:57 nolTvqMT
* $(#o)r>_R
* To change this template, choose Tools | Options and locate the template under T|ZT&x$z
* the Source Creation and Management node. Right-click the template and choose ||9f@9
* Open. You can then make changes to the template in the Source Editor. &=@R,
*/ (#\3XBG
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package com.tot.count; ]:m*7p\uk
import tot.db.DBUtils; efZdtrKgy
import java.sql.*; z&cfFx#h)
/** ely&'y!
* wp.'M?6`L
* @author m6+2rD
*/ PY)C=={p
public class CountControl{ ,Sghi&Ky
private static long lastExecuteTime=0;//上次更新时间 F''4 j8
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 |'Ve75 W6u
/** Creates a new instance of CountThread */ FSc730rM
public CountControl() {} >L[,.}(9
public synchronized void executeUpdate(){ QF!K$?EU[
Connection conn=null; L$lo5
PreparedStatement ps=null; zVkHDT[
try{ Y2<Z"D`
conn = DBUtils.getConnection(); LEHlfB#z`@
conn.setAutoCommit(false); |I85]'K9a
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); }yS"C fM
for(int i=0;i<CountCache.list.size();i++){ rbQA6_U 5A
CountBean cb=(CountBean)CountCache.list.getFirst(); B RD>q4w
CountCache.list.removeFirst(); r$G;^
ps.setInt(1, cb.getCountId()); Eu1s
ps.executeUpdate();⑴ ag[ yM
//ps.addBatch();⑵ khc5h^0
} x\I9J4Q
//int [] counts = ps.executeBatch();⑶ B~LB^
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conn.commit(); -wvJZ
}catch(Exception e){ b>Vs5nY!
e.printStackTrace(); pd>EUdbrp&
} finally{ BU]9eF!>h
try{ ?HZ+fS,-
if(ps!=null) { :%!=Ej.J
ps.clearParameters(); )k0bP1oGS
ps.close(); >:KPvq!0
ps=null; dRas9g
} } [D[ZLv
}catch(SQLException e){} |Z#)1K
DBUtils.closeConnection(conn); 3U1xKF
} ^9qncvV
} |F9/7 z\5+
public long getLast(){ B@.U\.
return lastExecuteTime; w}oH]jVKL6
} l&;#`\s!V
public void run(){ p.8G]pS
long now = System.currentTimeMillis(); qhL e[[>
if ((now - lastExecuteTime) > executeSep) { jpOi Eo
//System.out.print("lastExecuteTime:"+lastExecuteTime); >*vI:MG8
//System.out.print(" now:"+now+"\n"); j31
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); yd`.Rb&V
lastExecuteTime=now; f0MHh5
executeUpdate(); -`f JhQ|
} l.>QO ;
else{ j~Rh_\>Q
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 6i{W=$RQ
} aHwrFkn
} lZ/Yp~2S
} G)'cd D1
//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 E83{4A4
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类写好了,下面是在JSP中如下调用。 RHVMlMX
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<% #sAEIk/
CountBean cb=new CountBean(); O_KL#xo
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); DQKhR sC
CountCache.add(cb); vIz~B2%x
out.print(CountCache.list.size()+"<br>"); J}%&;uv
CountControl c=new CountControl(); wQ4/eQ*
c.run(); M6y:ze
out.print(CountCache.list.size()+"<br>"); "d%":F(
%>