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: &@lfr623
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CountBean.java >` s"C
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/* TnQ>v{Rx
* CountData.java P&Keslk
* Ll|-CY $
* Created on 2007年1月1日, 下午4:44 .?u<|4jE6
* iYr)Ao5X
* To change this template, choose Tools | Options and locate the template under lrE"phYk
* the Source Creation and Management node. Right-click the template and choose TdPd8ig8{
* Open. You can then make changes to the template in the Source Editor. "}3sL#|z
*/ PSJj$bt;<+
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package com.tot.count; Ll
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/** 5{HF'1XgZ*
* H q6%$!q
* @author UV2W~g
*/ }R;}d(C`
public class CountBean { 1WtE ]
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private String countType; "w?0f["
int countId; tl_3 %$s
/** Creates a new instance of CountData */ @g#5d|U);
public CountBean() {} ejd_ 85$
public void setCountType(String countTypes){ c+ZOC8R
this.countType=countTypes;
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} Z#}sK5s
public void setCountId(int countIds){ %UI^+:C
this.countId=countIds; j/aJD E(+
} kEh\@x[
public String getCountType(){ 4ior
return countType; ovp/DM
} Qhj']>#g
public int getCountId(){ 1i#y>fUj
return countId; 0PkX- .
} X2V+cre
} ;y(;7n_ a
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CountCache.java k[8F: T-
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/* I7_8oq\3D
* CountCache.java k<1i.rh
* 2{j$1EdI@-
* Created on 2007年1月1日, 下午5:01 L]MWdD
* gs1yWnSv5
* To change this template, choose Tools | Options and locate the template under _S) K+C|@
* the Source Creation and Management node. Right-click the template and choose frcX'M}%
* Open. You can then make changes to the template in the Source Editor. K3mP 6Z#2
*/ *Hx*s_F
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package com.tot.count; IFBt#]l0
import java.util.*; (wL$h5SG
/** u0#KBXRo
* (K[e=0Rf
* @author e\X[\ve
*/ /rpr_Xw}
public class CountCache { ^1 ){
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public static LinkedList list=new LinkedList(); 6
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/** Creates a new instance of CountCache */ hr]+4!/
public CountCache() {} Vja 4WK*
public static void add(CountBean cb){ waMV6w)<
if(cb!=null){ i1x4$}
list.add(cb); *w;?&)8%
} [.>=>KJ_
} 79 4UY
} K1X-<5]{
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CountControl.java /}1|'?P
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/* "81'{\(I_
* CountThread.java <6;M\:Y*T
* pmP~1=3
* Created on 2007年1月1日, 下午4:57 _Yo)m|RaB
* '|gsmO
* To change this template, choose Tools | Options and locate the template under n#}@|"J
* the Source Creation and Management node. Right-click the template and choose \SmsS^z(]
* Open. You can then make changes to the template in the Source Editor. V06*qQ[
*/ f&$Bjq
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package com.tot.count; A o*IshVh
import tot.db.DBUtils; /{l_tiE7
import java.sql.*; ;R6f9tu2
/** m|fcWN[
* AO`@&e]o
* @author XcNL\fl1
*/ HIw)HYF2
public class CountControl{ s YTJ^K d
private static long lastExecuteTime=0;//上次更新时间 T%.Yso{
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 DSHvBFQ
/** Creates a new instance of CountThread */ ^GV'Y
public CountControl() {} =( ZOn=IL
public synchronized void executeUpdate(){ 346 z`5
Connection conn=null; "yH?df24
PreparedStatement ps=null; !r.-7hR $
try{ D'[:35z
conn = DBUtils.getConnection(); wDi/oH/H
conn.setAutoCommit(false); vKnZ= =B
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); V_
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for(int i=0;i<CountCache.list.size();i++){ =xkaF)AW&v
CountBean cb=(CountBean)CountCache.list.getFirst(); PW@ :fM:q
CountCache.list.removeFirst(); [>`.,k
ps.setInt(1, cb.getCountId()); W'9{2h6u(
ps.executeUpdate();⑴ TAh'u|{u2
//ps.addBatch();⑵ H,c1&hb/w
} *-*V>ntvT$
//int [] counts = ps.executeBatch();⑶ nZ=[6?
conn.commit(); >3g`6d
}catch(Exception e){ hAUP#y@:H:
e.printStackTrace(); W\j'8^kI9
} finally{ I wj[ ^
try{ L[44D6Vg
if(ps!=null) { E[t[R<v,P!
ps.clearParameters(); VEa"^{,w
ps.close(); :C^{Lc
ps=null; [BdRx`
} 78]*Jx>L
}catch(SQLException e){} a9&[Qv5-/
DBUtils.closeConnection(conn); \roJf&O }
} pGU.+[|(
} W0x9^'=s\
public long getLast(){ v8)wu=u
return lastExecuteTime; Ib{#dhV
} 8Mtd}{Fw*
public void run(){ hTO5*5]0zP
long now = System.currentTimeMillis(); m^BXLG:b
if ((now - lastExecuteTime) > executeSep) { 5vD\?,f E
//System.out.print("lastExecuteTime:"+lastExecuteTime); h)sT37
//System.out.print(" now:"+now+"\n"); 'r=2f6G>cP
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); W 8`6O2
lastExecuteTime=now; B{0]v-w
executeUpdate(); _fgsHx>l7
} (soTkH:#
else{ c^"4l
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//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); nv0D4 t
} 851BOkRal4
} q/w5Dx|:
} `dF~'
//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 6|Dtx5
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类写好了,下面是在JSP中如下调用。 R%LFFMVn
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<% cb'Ya_
CountBean cb=new CountBean(); s8:epcL`A
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); Msvs98LvW
CountCache.add(cb); ai/]E6r
out.print(CountCache.list.size()+"<br>"); i+QVs_jW
CountControl c=new CountControl(); 'N6oXE
c.run(); 7gLk~*
out.print(CountCache.list.size()+"<br>"); vC&0UNe$
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