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: x?<FJ"8"k
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CountBean.java NHE18_v5
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/* NxILRKwO
* CountData.java 0"SU_jQzv
* ~.|_ RdN
* Created on 2007年1月1日, 下午4:44 w32y3~
* LR3*G7
* To change this template, choose Tools | Options and locate the template under fN2lLn9/u
* the Source Creation and Management node. Right-click the template and choose y1#1Ne_
* Open. You can then make changes to the template in the Source Editor. 7}mFL*
*/ wuo,kM
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package com.tot.count; iURe( [@
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/** 5lum $5
* |':{lH6+1
* @author y
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*/ n&!-9:0
public class CountBean { }QmqoCAE~m
private String countType; _u Il
int countId; xYB{;K
/** Creates a new instance of CountData */ ;F Eqe49
public CountBean() {} pK4)yu+
public void setCountType(String countTypes){ K)P%;X
this.countType=countTypes; Tj- s4x
} O".=r}
public void setCountId(int countIds){ QsW/X0YBv
this.countId=countIds; Fj!U|l\_9
} H;"4C8K7
public String getCountType(){ !`r$"}g
return countType; )M^
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} ]_$[8#kg
public int getCountId(){ |l!aB(NW
return countId; |[y6Ua0
} D/' dTrR
} +H2Qk4XFB
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CountCache.java Ea=P2:3*
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/* 6w7 7YTJ
* CountCache.java *z2s$EZ
* f
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* Created on 2007年1月1日, 下午5:01 Q59W#e)
* W_ZJ0GuE(
* To change this template, choose Tools | Options and locate the template under @o.I ;}*N
* the Source Creation and Management node. Right-click the template and choose !_(Tqyg&
* Open. You can then make changes to the template in the Source Editor. W{aY}`
*/ Ir]\|t
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package com.tot.count; ?h2}#wg
import java.util.*; {GUF;V
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/** 4GM6)"#d
* ,z?':TZ
* @author A2Tw<&Tw(
*/ ,u!sjx
public class CountCache { aQ~s`^D
public static LinkedList list=new LinkedList(); -K$)DvV^(E
/** Creates a new instance of CountCache */ wA.\i
public CountCache() {} :@&/kyGH
public static void add(CountBean cb){ wQLSf{2
if(cb!=null){ DTs;{c
list.add(cb); +/\6=).\
} ']oQ]Yx0
} K|@G t%Y
} tMe ~vq[
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CountControl.java 1 {)Q[#l
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/* azU"G(6y?+
* CountThread.java Y^]rMK/;
* O
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* Created on 2007年1月1日, 下午4:57 .p$(ZH =~
* K+iP6B
* To change this template, choose Tools | Options and locate the template under y> (w\K9W
* the Source Creation and Management node. Right-click the template and choose 8>%hz$no=
* Open. You can then make changes to the template in the Source Editor. (iGTACoF
*/ ~{gqsuCCL
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package com.tot.count; B1Oq!k
import tot.db.DBUtils; \[nut;
import java.sql.*; =Runf
+}
/** LHmZxi?
* Rva$IX^]
* @author C.QO#b
*/ JN6B~ZNf
public class CountControl{ 'm9` 12H
private static long lastExecuteTime=0;//上次更新时间 uVU)d1N
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 rQ9'bCSr%
/** Creates a new instance of CountThread */ P>6{&(
public CountControl() {} aN=B]{!
public synchronized void executeUpdate(){ r%N)bNk~
Connection conn=null; J-4:H
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PreparedStatement ps=null; 'W#D(l9nI
try{ 1nOCQ\$l
conn = DBUtils.getConnection(); bN88ua}k{
conn.setAutoCommit(false); iR0y"Cii
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); O1kl70,`R
for(int i=0;i<CountCache.list.size();i++){ L4f3X~8,b
CountBean cb=(CountBean)CountCache.list.getFirst(); 9C i-v/M]
CountCache.list.removeFirst(); cGD(.=
ps.setInt(1, cb.getCountId()); DeYV$W
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ps.executeUpdate();⑴ yppo6HGD
//ps.addBatch();⑵ D3A/l
} S@sO;-^+
//int [] counts = ps.executeBatch();⑶ u-C)v*#L
conn.commit(); i@CxI<1'
}catch(Exception e){ iyog`s c
e.printStackTrace(); 39jG8zr=Z[
} finally{ -{+}@?
try{ l@:0e]8|o
if(ps!=null) { wdZ/Xp9]
ps.clearParameters(); #89!'W
ps.close(); =rK+eG#,
ps=null; >OK^D+v"j
} 8.~kK<)!
}catch(SQLException e){} a'z7(8$$
DBUtils.closeConnection(conn); 1i] ^{;]
} FCn_^l)EA
} Tb-F]lg$
public long getLast(){ -`t^7pr
return lastExecuteTime; snikn&
} i 3SHg\~Z
public void run(){ 2:=
long now = System.currentTimeMillis(); 8sCv]|cn
if ((now - lastExecuteTime) > executeSep) { ]0\MmAJRn
//System.out.print("lastExecuteTime:"+lastExecuteTime); O| hpXkV
//System.out.print(" now:"+now+"\n"); t()c=8qF|u
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); r"R#@V\'1b
lastExecuteTime=now; ri.I pRe
executeUpdate(); zv"Z DRW
} Hq 188<
else{ .GcKa024
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); j8`BdKg
} u~-8d;+?y
} eR" <33{
} BF <ikilR
//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 {qMIGwu
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类写好了,下面是在JSP中如下调用。 2 Vrw
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<% IaXeRq?<
CountBean cb=new CountBean(); fd2T=fz-
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); O7IJ%_A&
CountCache.add(cb); 8&aq/4:q0
out.print(CountCache.list.size()+"<br>"); k@:%:Sj 2
CountControl c=new CountControl(); K96<M);:g
c.run(); (!N|Kl
out.print(CountCache.list.size()+"<br>"); JO<wU
%>