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: VPXUy=W
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CountBean.java Xg1QF^
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/* #w#:f
* CountData.java _tQR3I5
* p;9"0rj,z
* Created on 2007年1月1日, 下午4:44 Bh<6J&<n
*
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* To change this template, choose Tools | Options and locate the template under OS$^>1f"
* the Source Creation and Management node. Right-click the template and choose phqmr5s^H
* Open. You can then make changes to the template in the Source Editor. QlK]2r9
*/ ~-o[v-\
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package com.tot.count; 0}I aWd^4
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/** xh9Os <
* q!\4|KF~
* @author bGe@yXId5
*/ .V`N^H:l
public class CountBean { o0:RsODl
private String countType; L/2,r*LNx$
int countId; Ipyr+7/zJ
/** Creates a new instance of CountData */ m>ApN@n
public CountBean() {} gX!-s*{E
public void setCountType(String countTypes){ \d}>@@U&
this.countType=countTypes; .h[yw$z6
} LF\HmKM,
public void setCountId(int countIds){ NNP ut$.
this.countId=countIds; /K\]zPq
} EK$3T5e
public String getCountType(){ nv/'C=+L
return countType; $ucA.9pJ
} M A
public int getCountId(){ E]dmXH8A
return countId; oA]rwaUX
} aV`_@F-8
} g=]VQ;{
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CountCache.java ![9umsx
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/* CWw#0
* CountCache.java b ]u01T-
* %+HZ4M+hV
* Created on 2007年1月1日, 下午5:01 yU'<b.]
* <S68UN(Ke
* To change this template, choose Tools | Options and locate the template under 0Tq=nYZA
* the Source Creation and Management node. Right-click the template and choose 2$s2u;
* Open. You can then make changes to the template in the Source Editor. &ws^Dm]R
*/ fv/Nf"
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package com.tot.count; 4Be'w`Q {
import java.util.*; `R6dnbH
/**
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* jiqE^j3;
* @author ! N'HL-oT
*/ |Q?^B a
public class CountCache { XDohfa_
public static LinkedList list=new LinkedList(); N`et]'_A}
/** Creates a new instance of CountCache */ ce:p*
public CountCache() {} v8f1o$R
public static void add(CountBean cb){ Bht! +
if(cb!=null){ WJj5dqatV
list.add(cb); -+{<a!Nb
} U'k 0;
} fs\A(]`$
} b|oT!s
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CountControl.java cPy/}A
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/* D$Eq~VQ
* CountThread.java yc+pNC)ue_
* !
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* Created on 2007年1月1日, 下午4:57 AW8*bq1
* B;e (5y-
* To change this template, choose Tools | Options and locate the template under 03H0(ku=
* the Source Creation and Management node. Right-click the template and choose y4)iL?!J~
* Open. You can then make changes to the template in the Source Editor. M>[e1y>7
*/ Hg5:>?Lw@
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package com.tot.count; nM|Cv
import tot.db.DBUtils; E.N
import java.sql.*; #f<3[BLx
/** S`8Iu[Ma
* Z5|BwM
* @author );;UA6CD
*/ .F},Z[a&
public class CountControl{ T/]f5/
private static long lastExecuteTime=0;//上次更新时间 .tcdqL-'
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 T.}Y&,n$$5
/** Creates a new instance of CountThread */ @ Fkhida
public CountControl() {} rld8hFj
public synchronized void executeUpdate(){ VYjt/\Z
Connection conn=null; {$g3R@f^~
PreparedStatement ps=null; AVi&cvhs
try{ nvQTJ4,,
conn = DBUtils.getConnection(); )$ M2+_c
conn.setAutoCommit(false); LhRd0
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Swr4De_5
for(int i=0;i<CountCache.list.size();i++){ QQJf;p7
CountBean cb=(CountBean)CountCache.list.getFirst(); 3 3zE5vr
CountCache.list.removeFirst(); < 1[K1'7h
ps.setInt(1, cb.getCountId()); sGa}Cf;H@g
ps.executeUpdate();⑴ Ad&VOh+0
//ps.addBatch();⑵ $[UUf}7L
} CEW1T_1U<\
//int [] counts = ps.executeBatch();⑶ A `{hKS
conn.commit(); }O Y/0p-Z
}catch(Exception e){ X,{ 3_
e.printStackTrace(); ALj~e#{;z
} finally{ BP}@E$
try{ F3hG8YX
if(ps!=null) { E!_3?:[S_
ps.clearParameters(); #a9O3C/MP
ps.close(); 5;+KMM:zb
ps=null; ,x$^^
} y @S_CB47
}catch(SQLException e){} dIfy!B"
DBUtils.closeConnection(conn); Y_K W9T_
} NSM7n=
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} Ol~M
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public long getLast(){ l dqU#{
return lastExecuteTime; pH3<QNq5
} PMUW<UI
public void run(){ Z&O6<=bg!
long now = System.currentTimeMillis(); tzthc*-<
if ((now - lastExecuteTime) > executeSep) { jD${ZIv
//System.out.print("lastExecuteTime:"+lastExecuteTime); SA7(EJ95
//System.out.print(" now:"+now+"\n"); `/^
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); M*f]d`B
lastExecuteTime=now; P?S]Q19Q4
executeUpdate(); 5vg="@O K
} (zh[1[a
else{ xv&h>GOg
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); oC-v>&bW
} yzv"sd[8N
} f,4erTBH
} `nKN|6o#x
//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 ^=5x1<a9$
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类写好了,下面是在JSP中如下调用。 Ek1c >s,t
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<% 2,wwI<=E'
CountBean cb=new CountBean(); N<1+aL\
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); -]+pwZ4g
CountCache.add(cb); "F%JZO51
out.print(CountCache.list.size()+"<br>"); [q Uv|l1
CountControl c=new CountControl(); vxHFNGI
c.run(); r!
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out.print(CountCache.list.size()+"<br>"); G:p85k`
%>