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: -4}I02
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CountBean.java JW`Kh*,~<
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/* /nX+*L}d/
* CountData.java UdSu:V|
* YflotlT}
* Created on 2007年1月1日, 下午4:44 7+h*&f3>
* VB+sl2V<h
* To change this template, choose Tools | Options and locate the template under N%2UL&w#B
* the Source Creation and Management node. Right-click the template and choose j5cc"s
* Open. You can then make changes to the template in the Source Editor. _z3Hl?qk=
*/ BhMHT:m
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package com.tot.count; YBX7WZCR
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/** &M,"%w!
* !Qg%d&q.Sx
* @author E9Q?@' h
*/ ^1%gQ@P
public class CountBean { Q)l]TgvSe
private String countType; c0 H8FF3
int countId; xYMNyj~
/** Creates a new instance of CountData */ GC3:ZpV`
public CountBean() {} I:~L!%
public void setCountType(String countTypes){ Efb S*f5
this.countType=countTypes; '9,14e6
} n
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public void setCountId(int countIds){ n},~2
this.countId=countIds; q5$z:'zE
} by {G{M`X
public String getCountType(){ X-Sso9/q.
return countType; 35Jno<TP'
} NRS!Ox
public int getCountId(){ k?.HW?=zy
return countId; 7eh|5e$@
} `9QrkkG+
} X;5U@l
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CountCache.java MwxfTH"wi
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/* {-rK:*yP'u
* CountCache.java [@}{sH(#Ta
* JH~v e
* Created on 2007年1月1日, 下午5:01 (BC3[R@/l
* ? OBe!NDf
* To change this template, choose Tools | Options and locate the template under b; SFnZa8
* the Source Creation and Management node. Right-click the template and choose %J`;
* Open. You can then make changes to the template in the Source Editor. SnbH`\U"
*/ ~Exd_c9
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package com.tot.count; 4\q7.X+^
import java.util.*; m_H$fioha,
/** FhB^E$r%
* r'hr'wZ
* @author !oU$(,#9
*/ Ep}KIBBO
public class CountCache { -[#Mx}%
public static LinkedList list=new LinkedList(); :^SpKe(7
/** Creates a new instance of CountCache */ KQ/v](77
public CountCache() {} Z*kGWL
public static void add(CountBean cb){ }>xgzhdT
if(cb!=null){ $ 8w
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list.add(cb); v&(X&q
} FTt7o'U
} ?B %y)K
} -8tWc]c
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CountControl.java %^"T z,f
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/* lN+NhPF
* CountThread.java ^ h^2='p
* 9B'l+nP
* Created on 2007年1月1日, 下午4:57 BzA(yCu$:
* 0+8ThZ?n
* To change this template, choose Tools | Options and locate the template under dv%gmUUf}k
* the Source Creation and Management node. Right-click the template and choose j:|60hDz^
* Open. You can then make changes to the template in the Source Editor. >w9)c|
*/ ~`hI|i<]
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package com.tot.count; #'<I!G
import tot.db.DBUtils; )QTk5zt
import java.sql.*; nl5K1!1
/** %>i7A?L
* ue/6DwUv
* @author c6s(f
*/ (eJr-xZ/
public class CountControl{ ?9!tMRb
private static long lastExecuteTime=0;//上次更新时间 D{.%Dr?
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 X>%2\S
/** Creates a new instance of CountThread */ ^i-%FY_i5}
public CountControl() {} -ihF)^"a
public synchronized void executeUpdate(){ WGG|d)'@
Connection conn=null; A>>@&c:(
PreparedStatement ps=null; ^Sy\<
try{ )0AE*S
conn = DBUtils.getConnection(); 4,s: G.g
conn.setAutoCommit(false); .1I];Cy0D
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); 4PD"[a="
for(int i=0;i<CountCache.list.size();i++){ ADv
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CountBean cb=(CountBean)CountCache.list.getFirst(); ":7cZ1VN2
CountCache.list.removeFirst(); Yc?t aL)
ps.setInt(1, cb.getCountId()); #A]7cMZ'W
ps.executeUpdate();⑴ c#"\&~. P
//ps.addBatch();⑵ dhK$XG
} !kASEjFz|f
//int [] counts = ps.executeBatch();⑶ @dCu]0oNI
conn.commit(); 5Tu#o()
}catch(Exception e){ |,sUD/rt
e.printStackTrace(); f[.hN
} finally{ =#Vdz=.
try{ ;%dkwKO
if(ps!=null) { U"m!f*a
ps.clearParameters(); Q^MB%L;D
ps.close(); D4'XBXmb
ps=null; hD>:WJ
} i;)g0}x`
}catch(SQLException e){} 3<mv9U(
DBUtils.closeConnection(conn); @%\ANM$S
} F|P2\SPL
} 3sp*.dk
public long getLast(){ Z7.)[
;
return lastExecuteTime; >D:S)"
} 'dU$QO
public void run(){ 3:Z(tM&-O
long now = System.currentTimeMillis(); &/JnAfmYqt
if ((now - lastExecuteTime) > executeSep) { ?sS'T7r
v
//System.out.print("lastExecuteTime:"+lastExecuteTime); _L$)~},cT
//System.out.print(" now:"+now+"\n"); "BFW&<1
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); qsk71L
lastExecuteTime=now; 5\4>H6
executeUpdate(); }7.q[ ^oF
} U1q$B32
else{ *|E@81s#
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); TS[Z<m
} X! 2|_
} yPQ{tS*t
} 1MahFeQ[
//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 ]#:xl}'LS
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类写好了,下面是在JSP中如下调用。 +z[!]^H]4
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<% vy#c(:UQR
CountBean cb=new CountBean(); X^.r@tT
cb.setCountId(Integer.parseInt(request.getParameter("cid")));
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CountCache.add(cb); CqX%V":2
out.print(CountCache.list.size()+"<br>"); Z^~6pH\
CountControl c=new CountControl(); Aj`4uFhiL
c.run(); <.v6w*+{/
out.print(CountCache.list.size()+"<br>"); ?Jr<gn^D
%>