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: s iv
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CountBean.java Os8]iNvW\
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/* u3 ?+Hu|*T
* CountData.java ygUvO3Z
* S,3e|-&$
* Created on 2007年1月1日, 下午4:44 X&M4c5Li
* kd'qYh
* To change this template, choose Tools | Options and locate the template under QhZ!A?':U
* the Source Creation and Management node. Right-click the template and choose [gzw<b:`
* Open. You can then make changes to the template in the Source Editor. ss,t[`AV{
*/ YT,1E>rd
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package com.tot.count; n4k.tq
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/** =t&B8+6
* CHWyy
* @author tJ.LPgfZ
*/ {)ZbOq2
public class CountBean { b\gl9"X
private String countType; \D, 0
int countId; 4VaUa8 D
/** Creates a new instance of CountData */ '_r|L1
public CountBean() {} w69`vK
public void setCountType(String countTypes){ >eAlz4
this.countType=countTypes; A~nq4@uj
} Xj+1]KRN
public void setCountId(int countIds){ ?*,N
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this.countId=countIds; {E6b/G?Q
} )@1_Dm@0b
public String getCountType(){ IOTHk+w
return countType; =#T6,[5
} |KU>+4=
@
public int getCountId(){ gl.P#7X
return countId; v]U[7 j
} '$1-A%e$1
} Q`AJR$L
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CountCache.java $L:g7?)k
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/* XuR!9x^5
* CountCache.java ./5|i*ow
* T"9`[Lzva
* Created on 2007年1月1日, 下午5:01 4(u+YW GX
* dW8'$!@!!
* To change this template, choose Tools | Options and locate the template under \^N9Q9{7]
* the Source Creation and Management node. Right-click the template and choose wvT!NN
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* Open. You can then make changes to the template in the Source Editor. 5>}L3r>a;
*/ C"IPCJYn
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package com.tot.count; kc~Z1
import java.util.*; `U(A 5
/** ttZ!P:H2
* `j4ukOnG
* @author Pm+H!x,
*/ Eto0>YyZ
public class CountCache { |4X:>Ut]
public static LinkedList list=new LinkedList(); x*BfRj
/** Creates a new instance of CountCache */ rCYNdfdpp
public CountCache() {} )F4er'
public static void add(CountBean cb){ 1vl~[
if(cb!=null){ ! ~&X1,l1*
list.add(cb); z?j~ 2K<4
} l4R:_Z<
} I \vu?$w
} QhpE 2ICU
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CountControl.java sHQe0"Eo
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/* ^!pagt^
* CountThread.java Fo?2nQ<
* u@|GQXC
* Created on 2007年1月1日, 下午4:57 bG.aV#$FIg
* 2!]':(8mR
* To change this template, choose Tools | Options and locate the template under tTWYlbDFN
* the Source Creation and Management node. Right-click the template and choose Gtg;6&2
* Open. You can then make changes to the template in the Source Editor. [2)Y0; ["
*/ bmt2~!
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package com.tot.count; N<N!it
import tot.db.DBUtils; I!# 42~\
import java.sql.*; 7|,5;
/** oxcAKo
* (]mN09uE
* @author ? 76jz>;b
*/ =H!u4
public class CountControl{ 9-bDgzk
private static long lastExecuteTime=0;//上次更新时间 /:U\U_j
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 *(o~pxFTR
/** Creates a new instance of CountThread */ x]y~KbdeB
public CountControl() {} YM1@B`yWE
public synchronized void executeUpdate(){ n/^wzG
Connection conn=null; "V?U^L>SF
PreparedStatement ps=null; p(U'c}@2
try{ SwSBQq%h]M
conn = DBUtils.getConnection(); eT}c_h)
conn.setAutoCommit(false); G'{4ec0<{
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); RE*UIh*O
for(int i=0;i<CountCache.list.size();i++){ }ZvL%4jT
CountBean cb=(CountBean)CountCache.list.getFirst(); c(YNv4*X
CountCache.list.removeFirst(); fS!%qr
ps.setInt(1, cb.getCountId()); 3(AgUq
ps.executeUpdate();⑴ 8b|&
//ps.addBatch();⑵ (kb^=kw#0
} 'y;[
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//int [] counts = ps.executeBatch();⑶ 5&+
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conn.commit(); a8Ci 7<V
}catch(Exception e){ @uT\.W:Q2
e.printStackTrace(); nuKjp Ap!
} finally{ W~dS8B=<
try{ .rN5A+By`
if(ps!=null) { |*OS;FD5
ps.clearParameters(); v0=^Hym
ps.close(); }1d
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ps=null; I.q nA
} k\x>kJ}0
}catch(SQLException e){} 7c4\'dt#
DBUtils.closeConnection(conn); 2hmV1gj
} ]hL 1qS
} \gj@O5rG P
public long getLast(){ -i?!em'J
return lastExecuteTime; *Swb40L^
} 0'z$"(6D
public void run(){ ~G5)ya-
long now = System.currentTimeMillis(); ,Iwri\
if ((now - lastExecuteTime) > executeSep) { H%Q@DW8~@
//System.out.print("lastExecuteTime:"+lastExecuteTime); Qmzj1e$6x
//System.out.print(" now:"+now+"\n"); ldi'@^
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); J%3S3C2*m
lastExecuteTime=now; ;se-IDN
executeUpdate(); ']A+wGR&r
} S-'iOJ1]
else{ 3EF|1B/5
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); IqcPml{\
} c%Kv"Z%f
} QfT&y &
} 3V LwMF?
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 }T4"#'`
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类写好了,下面是在JSP中如下调用。 f=g/_R2$xN
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<% 6-QTqb?U;N
CountBean cb=new CountBean(); Yz\z
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cb.setCountId(Integer.parseInt(request.getParameter("cid"))); { S4?L8
CountCache.add(cb); 'S E%9
out.print(CountCache.list.size()+"<br>"); V:F)m!
CountControl c=new CountControl(); 7cY_=X-?Y
c.run(); T3%yV*F,
out.print(CountCache.list.size()+"<br>"); D3(|bSca
%>