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: 1Y_fX
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CountBean.java wP'`!O[W
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/* sz5@=
* CountData.java ! JN@4
* XT\;2etVL
* Created on 2007年1月1日, 下午4:44 &yuerNK
* Oc1ZIIkh\
* To change this template, choose Tools | Options and locate the template under BC^WPr
* the Source Creation and Management node. Right-click the template and choose xxYFWvi
* Open. You can then make changes to the template in the Source Editor. 1E(pJu'K
*/ d)@MMF
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package com.tot.count; Ek:u[Uw\
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/** 6%>0g^`)9Y
* q\\J9`Q$J
* @author mmi~A<
*/ K)n( U9#
public class CountBean { "+Kr1nW
private String countType; +oc}kv,h]
int countId; Wr;)3K
/** Creates a new instance of CountData */ H]-nm+
public CountBean() {} !eW<4jYB
public void setCountType(String countTypes){ a2z o_h2R
this.countType=countTypes; %(i(ZW "
} m@ ~HHwj
public void setCountId(int countIds){ /*[a>B4-q
this.countId=countIds; CBc}N(9
} 8w$cj'
public String getCountType(){ d7@ N~<n
return countType; PO#FtG
} FU<rE&X2:
public int getCountId(){ }k%>%xQ.
return countId; 5<61NnZ
} _=rXaTp
} ,YH.n>`s+
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CountCache.java 9P]TIV.
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/* {\k9%2V*+
* CountCache.java ;9rQN3J$gn
* k[][Md2Vh
* Created on 2007年1月1日, 下午5:01 `g #\ Ws
* E:7vm@+
* To change this template, choose Tools | Options and locate the template under g
wk\[I`;
* the Source Creation and Management node. Right-click the template and choose :=* -x
* Open. You can then make changes to the template in the Source Editor. V[%r5!83H
*/ R,(^fM
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package com.tot.count; <1ai0]
import java.util.*; HtMlSgx,8>
/** Z"P{/~HG
* @9^kl$
* @author v<O\ l~S
*/ <ioX|.7ZX
public class CountCache { wH<S0vl
public static LinkedList list=new LinkedList(); n_5g:`Y
/** Creates a new instance of CountCache */ tZ(Wh
public CountCache() {} /(Y\ <
public static void add(CountBean cb){ !-: a`Vs+
if(cb!=null){ f+d{^-
list.add(cb); X;- ,3dy
} a].Bn#AH!C
} ]UMwpL&rY
} Od"-w<'
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CountControl.java L&eO?I=,
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/* NKd):>d%
* CountThread.java 9[:nWp^
* /wmJMX
* Created on 2007年1月1日, 下午4:57 `toSU>:
* kG%<5QH
* To change this template, choose Tools | Options and locate the template under iud%X51
* the Source Creation and Management node. Right-click the template and choose A:N!H_x
* Open. You can then make changes to the template in the Source Editor. fY>\VY$>
*/ !\p-|51
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package com.tot.count; rGoB&% pc
import tot.db.DBUtils; L/V3sSt
import java.sql.*; EQg
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/** o#;w>-
* 1W5YS +pf
* @author cZ5[A T
*/ 2t_E\W7w+
public class CountControl{ MEg|AhP
private static long lastExecuteTime=0;//上次更新时间 9~a_^m/
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 ~]N%
{;F}
/** Creates a new instance of CountThread */ 2PRGwK/
public CountControl() {} ?
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public synchronized void executeUpdate(){ Oyz=|[^,W
Connection conn=null; dNIY`u
PreparedStatement ps=null; fE7Kv_N-%
try{ vG<Mz?wr
conn = DBUtils.getConnection(); Dt8eVWkN ~
conn.setAutoCommit(false); jk) U~KGcg
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); zS.7O'I<'
for(int i=0;i<CountCache.list.size();i++){ ZWYwVAo
CountBean cb=(CountBean)CountCache.list.getFirst(); brZ3T`p+.P
CountCache.list.removeFirst(); wp$SO^?-
ps.setInt(1, cb.getCountId()); LM0TSB?
ps.executeUpdate();⑴ !m78 /[LW
//ps.addBatch();⑵ k~Gjfo
} WMrK8e'
//int [] counts = ps.executeBatch();⑶ 28zt.9
conn.commit(); d
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}catch(Exception e){ WpRi+NC}ln
e.printStackTrace(); |Y:T3hra61
} finally{ |`#[jHd
try{ Ie` `Wb=
if(ps!=null) { p_tMl%K
ps.clearParameters(); P^+Og_$
ps.close(); K&Zdk (l)
ps=null; mh|M O(
} jt?R
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}catch(SQLException e){} z^~fVl
DBUtils.closeConnection(conn); =n%?oLg^
} ^]OD+ v
} =w,%W^"E
public long getLast(){ ^1}}-9q
return lastExecuteTime; z.#gpTXD
} D4_D{\xhO
public void run(){ 6VRVk7"
long now = System.currentTimeMillis(); #uKHw2N
if ((now - lastExecuteTime) > executeSep) { 4ajBMgD]KG
//System.out.print("lastExecuteTime:"+lastExecuteTime); (n#
//System.out.print(" now:"+now+"\n"); eDG=-a4
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); |)1"*`z
lastExecuteTime=now; =T;%R^@
executeUpdate(); ^k~{6S,
} >pz/wTOi
else{ /ZX8gR5x
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); +STT(b Mn
} R0 {+Xd
} IC7n;n9
} :x= ZvAvo
//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 r0?`t!%V
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类写好了,下面是在JSP中如下调用。
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<% RDk{;VED{
CountBean cb=new CountBean(); S =eP/
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); *9*6n\~aI
CountCache.add(cb); ">NBPanJ
out.print(CountCache.list.size()+"<br>"); <Eq^rh
CountControl c=new CountControl(); rXvvJIbi
c.run();
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out.print(CountCache.list.size()+"<br>"); 8ec~"vGLz~
%>