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: I*}#nY0+
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CountBean.java Rs`a@Fn
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/* iI*7WO[W
* CountData.java F-^HN%
* `VtwKt*
* Created on 2007年1月1日, 下午4:44 G+uiZ(p>
* (fa?ftK
* To change this template, choose Tools | Options and locate the template under s3{s.55{m
* the Source Creation and Management node. Right-click the template and choose $)Yo g]}
* Open. You can then make changes to the template in the Source Editor. 3Mx@
*/ ]%|WE
#-T.@a1X
package com.tot.count; /BM1AV{s6
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/** iwQ-(GjM[A
* cO,V8#H
* @author \'Ta8
*/ Hc]1mM
public class CountBean { rf->mk{
private String countType; f_ztnRw
int countId; #OWs3$9
/** Creates a new instance of CountData */ A[kH_{to;
public CountBean() {} jJZsBOW[8
public void setCountType(String countTypes){ 8%<`$`FyU
this.countType=countTypes; 8/"|VE DOr
} V=&,^qZ
public void setCountId(int countIds){ gvNZrp>e!
this.countId=countIds; -j_I_
} R*Z]
public String getCountType(){ |xZcT4
return countType; rxj@NwAno
} ^,lZ58
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public int getCountId(){ Wk\@n+Q{]
return countId; ^Pd37&B4V
} _}OJPahw
} 8e!DDh
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CountCache.java T:dm0i au
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/* UZP6x2:=
* CountCache.java ;#s}b1
* 2BDan^:-Av
* Created on 2007年1月1日, 下午5:01 Wi[m`#
* :z.Y$]F@
* To change this template, choose Tools | Options and locate the template under drKjLo[y
* the Source Creation and Management node. Right-click the template and choose 9xn23*Fo
* Open. You can then make changes to the template in the Source Editor. S tnv>
*/ UVc<C
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package com.tot.count; N4mJU'_{
import java.util.*; +xfW`[.{
/** l (,;wAH
* xDJ+BQ<1A
* @author l(#ke
*/ yW^IN8fm
public class CountCache { {R-82% X
public static LinkedList list=new LinkedList(); kt{C7qpD
/** Creates a new instance of CountCache */ ZQ~myqx,+L
public CountCache() {} [W$Z60?RR
public static void add(CountBean cb){ C$LRY~\
if(cb!=null){ 6_<s=nTX
list.add(cb); c~UAr k S
} H [Lt%:r
} ouVjZF@kS
} 030U7 VT1
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CountControl.java EeJqszmH
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/* "6N~2q,SW
* CountThread.java 4su_;+]
* s`=/fvf.
* Created on 2007年1月1日, 下午4:57 ~r^5-\[hZ
* LuP?$~z
* To change this template, choose Tools | Options and locate the template under hiRR+`L%
* the Source Creation and Management node. Right-click the template and choose cZr G:\A
* Open. You can then make changes to the template in the Source Editor. hyb +#R
*/ Q"|kW[Sg
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package com.tot.count; %gu$_S
import tot.db.DBUtils; )p<fL
import java.sql.*; P$18Xno{
/** 3`k[!!
* :vK(LU0K
* @author NdsX*o@a
*/ =r@gJw:B
public class CountControl{ vZE|Z[M+<
private static long lastExecuteTime=0;//上次更新时间 *i?rJH
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 |vfujzRZ
/** Creates a new instance of CountThread */ +z|UpI
public CountControl() {} ~J1;tZS
public synchronized void executeUpdate(){ r|^lt7\
Connection conn=null; N(:nF5>_
PreparedStatement ps=null; 4e@&QOo`Cu
try{ H+VO.s.a
conn = DBUtils.getConnection(); 8Y\OCwO
conn.setAutoCommit(false); C NfJ:e2
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); LgP> u?]n
for(int i=0;i<CountCache.list.size();i++){ Qq T/1^imS
CountBean cb=(CountBean)CountCache.list.getFirst(); kqD*TJA
CountCache.list.removeFirst(); cXS;z.M\_
ps.setInt(1, cb.getCountId()); 0AK?{y U
ps.executeUpdate();⑴ O[IR|
//ps.addBatch();⑵ q*[!>\Z8
} 19F ;oFp
//int [] counts = ps.executeBatch();⑶ RQ^m6)BTo
conn.commit(); CYt jY~
}catch(Exception e){ #9D/jYK1X
e.printStackTrace(); .QXG"R
} finally{ @%OPy|=,{
try{ & =73D1A
if(ps!=null) { "mPSA Z
ps.clearParameters(); mPs%ZC
ps.close(); 4<T*i{[
ps=null; wfBuU>
} 7deAr$?Wx
}catch(SQLException e){} |Bx||=z`
DBUtils.closeConnection(conn); >-5td=:Z
} .!yWF?T8
} X-kXg)!Bg
public long getLast(){ ]6{(Hjt
return lastExecuteTime; qGnPnQc
} &so-O90
public void run(){ -RG8<bI,
long now = System.currentTimeMillis(); g.I(WJX0
if ((now - lastExecuteTime) > executeSep) { -ca7x`yo
//System.out.print("lastExecuteTime:"+lastExecuteTime); .[T'yc:=
//System.out.print(" now:"+now+"\n"); y]}b?R~p=
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); q.=^iz&m
lastExecuteTime=now; K,f* SXM
executeUpdate(); \G$QNUU
} @[MO,J&h
else{ + "cRhVR
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); +
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} #K=b%;>
} 7hB#x]oQo
} 59{;VY81
//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 >u=%Lz"J
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类写好了,下面是在JSP中如下调用。 `"a? a5]k
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<% |DN^NhtE
CountBean cb=new CountBean(); K;oV"KRK
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); R'6@n#:
CountCache.add(cb); gtD
out.print(CountCache.list.size()+"<br>"); i@P 9EU
CountControl c=new CountControl(); <7=&DpjI7F
c.run(); TC qkm^xv
out.print(CountCache.list.size()+"<br>"); O(VxMO
%>