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: N&lKo}hk
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CountBean.java *r]#jY4qx
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/* Z7R+'OC
* CountData.java 4'#
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* OKzk\F6
* Created on 2007年1月1日, 下午4:44 =t-503e.J
* ::kpAE]
* To change this template, choose Tools | Options and locate the template under ~#
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* the Source Creation and Management node. Right-click the template and choose /d-7n|#E
* Open. You can then make changes to the template in the Source Editor. *CXVA&?
*/ \(ZOt.3!J
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package com.tot.count; YY<e]CriU
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/** K?+Rq
* `{I-E5x
* @author .c.#V:XZ#U
*/ ;rH@>VrR
public class CountBean { pF"IDC
private String countType; O8ZHIs
int countId; PK*
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/** Creates a new instance of CountData */ .{W)E
public CountBean() {} sWnU*Q
public void setCountType(String countTypes){ YEqWTB|w
this.countType=countTypes; Bhrp"l
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} :!Tb/1
public void setCountId(int countIds){ v4Q8RE?
this.countId=countIds; {z}OZHJN
} ) 4'@=q
public String getCountType(){ BK]q^.7+:
return countType; FeFH_
} #VEHyz 6P
public int getCountId(){ z<mU$<
return countId; [(N<E/m %B
} %fz!'C_4
} SSF4P&
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CountCache.java "L" 6jT
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/* _\LAWQ|M4[
* CountCache.java vH#^ |u
* r 6STc,%5
* Created on 2007年1月1日, 下午5:01 +d736lLe%
* Sc*O_c3D
* To change this template, choose Tools | Options and locate the template under fm\IQqIK%
* the Source Creation and Management node. Right-click the template and choose pJ5Sxgv{;
* Open. You can then make changes to the template in the Source Editor. DFt1{qS8@u
*/ y(8AxsROp
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package com.tot.count; gI^*O@Q4{b
import java.util.*;
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/** 5A6d]
* PGHl:4`Es!
* @author 6l>$N?a
*/ xGeRoW(X
public class CountCache { 7m=tu?@
public static LinkedList list=new LinkedList(); puz~Rfn#*
/** Creates a new instance of CountCache */ JQ8wL _C>
public CountCache() {} X}xy
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public static void add(CountBean cb){ d1#;>MiU
if(cb!=null){ a ^b_&}y
list.add(cb); Bn/{J
} GV([gs
} amIG9:-1'
} v>71?te
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CountControl.java Khxl'qj
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/* fG5 U' Vw
* CountThread.java m$:o+IH/
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* Created on 2007年1月1日, 下午4:57 Uok?FEN
* lM5Xw
* To change this template, choose Tools | Options and locate the template under ]`&ws
* the Source Creation and Management node. Right-click the template and choose Nd*zSsVlq
* Open. You can then make changes to the template in the Source Editor. M: qeqn+
*/ ,xrXby|R"
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package com.tot.count; `2?9eXC
import tot.db.DBUtils; y!Q&;xO+!
import java.sql.*; kQ~*iY
/** $aX}i4F
* IXugnvyV
* @author Sf)VQ5U!Y
*/ ;z>)&F
public class CountControl{ hX]vZR&R
private static long lastExecuteTime=0;//上次更新时间 (<pc4#B@*
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 =$IjN v(?
/** Creates a new instance of CountThread */ 40oRO0p
public CountControl() {} m-UI^M,@<
public synchronized void executeUpdate(){ EOjo>w>
Connection conn=null; k9.2*+vvg
PreparedStatement ps=null; |jniI(
try{ Uax- z
conn = DBUtils.getConnection(); 8|`4D 'Ln
conn.setAutoCommit(false); qde.;Yv9
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); ]z,W1Zs?
for(int i=0;i<CountCache.list.size();i++){ iU\WV
CountBean cb=(CountBean)CountCache.list.getFirst(); %J?;@ G)r
CountCache.list.removeFirst(); |?SK.1pW
ps.setInt(1, cb.getCountId()); :~pPB#)nk
ps.executeUpdate();⑴ m0W5O gk
//ps.addBatch();⑵ 1+PLj[;jJ:
} SqTO~zGC
//int [] counts = ps.executeBatch();⑶ 37Z:WJ?
conn.commit(); Y6/'gg'&5
}catch(Exception e){ S\
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e.printStackTrace(); d$/BF&n
} finally{ U&|=dH]-
try{ h84}lxT^]
if(ps!=null) { ^PfFW
ps.clearParameters(); C$xU!9K[+
ps.close(); _gjsAbM
ps=null; cTFyF)
} G@anY=D\EB
}catch(SQLException e){} CEE`nn
DBUtils.closeConnection(conn); ;Id%{1
} 6)kF!/J
} 69 R8#M
public long getLast(){ :Q=Jn?Gjb
return lastExecuteTime; .
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} RZ9vQ\X
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public void run(){ 7E4=\vM
long now = System.currentTimeMillis(); eZ
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if ((now - lastExecuteTime) > executeSep) { T@uY6))>F
//System.out.print("lastExecuteTime:"+lastExecuteTime); <SUjz}_Oa:
//System.out.print(" now:"+now+"\n"); l
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// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 3HC aZ?Ry'
lastExecuteTime=now; a5:Q%F<!
executeUpdate();
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} ? r=cLC
else{ l~wx8
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); P}y}IR{6
} ^_r8R__S:
} .xuLvNyQr
} $$2\qN -
//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 b2.
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类写好了,下面是在JSP中如下调用。 z@^l1)m
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<% lqa.Nj
CountBean cb=new CountBean(); a1B_w#?8
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 0n|op:]BHM
CountCache.add(cb); bN@V=C3
out.print(CountCache.list.size()+"<br>"); &Jv j@,>$d
CountControl c=new CountControl(); wX" 6 S:
c.run(); 5zX;/n~
out.print(CountCache.list.size()+"<br>"); UHF.R>Ry
%>