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: }(na)B{m
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CountBean.java d{WOO)j
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/* 3h o'\Ysu/
* CountData.java +Swl$ab
* J1M9),
* Created on 2007年1月1日, 下午4:44 9}K
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* h3\(660>$
* To change this template, choose Tools | Options and locate the template under &'i.W}Ib!
* the Source Creation and Management node. Right-click the template and choose 3WGOftLzt
* Open. You can then make changes to the template in the Source Editor. 5Em.sz;:8
*/ gm:Y@6W
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package com.tot.count; 2=7[r-*E
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/** VJr ~h
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* wB[
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* @author )g-0b@z!n
*/ voP#}fD
public class CountBean { Kp;<z<
private String countType; NDe FY
int countId; nhm#_3!6A
/** Creates a new instance of CountData */ fpzEh}:H\
public CountBean() {} (YPG4:[
public void setCountType(String countTypes){ b'/:e#F
this.countType=countTypes; Z]Z&PbP
} `09[25?
public void setCountId(int countIds){ eXLdb-
this.countId=countIds; xo-}t5w6t
} 5Tidb$L;Du
public String getCountType(){ fo9V&NE
return countType; H\<PGC"_Y
} |`I9K#w3
public int getCountId(){ }U%E-:
return countId; 3][
} us:v/WTQ
} 2of+KI:
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CountCache.java /Vv)00
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/* sG|,#XQ
* CountCache.java gV5mERKs
* O15~\8#'
* Created on 2007年1月1日, 下午5:01 &MONg=s3
* 1iM(13jW
* To change this template, choose Tools | Options and locate the template under d-8g
* the Source Creation and Management node. Right-click the template and choose S->S p
* Open. You can then make changes to the template in the Source Editor. 5VN~?#K
*/ NfCo)C-t
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package com.tot.count; WUx2CK2N
import java.util.*; #Oa`P
/** h9. Yux
* z`dnS]q9
* @author r6:nYyF$)v
*/ p5nrPL
public class CountCache { 4]cr1K
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public static LinkedList list=new LinkedList(); D_w<igu!3
/** Creates a new instance of CountCache */ `V[ hE
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public CountCache() {} |;C;d"JC2
public static void add(CountBean cb){ THwq~c'
if(cb!=null){ Pn}oSCo
list.add(cb); Qeq=4Nq
} ciPq@kMV
} FlH=Pqc
} .MxMBrM
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CountControl.java eX^ F^(
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/* t |:XSJ9
* CountThread.java Fow{-cs_p
* ef:Zi_o
* Created on 2007年1月1日, 下午4:57 !-B|x0fs
* 3-![%u
* To change this template, choose Tools | Options and locate the template under *+ O
* the Source Creation and Management node. Right-click the template and choose QP6a,^];
* Open. You can then make changes to the template in the Source Editor. #t">tL
*/ )Z`OkkabnD
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package com.tot.count; R"71)ob4
import tot.db.DBUtils; vrsOA@ee3H
import java.sql.*; W%#LHluP
/** M;0\fUh;
* %BkPkQA
* @author niCq`!
*/ sQ82(N7l
public class CountControl{ {1vlz>82
private static long lastExecuteTime=0;//上次更新时间 # 9ZO1\
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 )x&>Cf<,
/** Creates a new instance of CountThread */ -s:NF;"
public CountControl() {} j&,%v+x
public synchronized void executeUpdate(){ /.1h_[K]
Connection conn=null; &<5oDdC
PreparedStatement ps=null; =I)Ex)
try{ wpJfP_H
conn = DBUtils.getConnection(); N..@}}
conn.setAutoCommit(false); iM{aRFL
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); h{VGhkU9f
for(int i=0;i<CountCache.list.size();i++){ p-%m/d?
CountBean cb=(CountBean)CountCache.list.getFirst(); ].
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CountCache.list.removeFirst(); !ma'*X
ps.setInt(1, cb.getCountId()); ]~m2#g%
ps.executeUpdate();⑴ -$j|&l
//ps.addBatch();⑵ 'A#l$pJp7
} #_fL[j&
//int [] counts = ps.executeBatch();⑶ ,09d"7`X
conn.commit(); =Wl}Pgo!
}catch(Exception e){ |?uUw$oh
e.printStackTrace(); d?OsVT;U
} finally{ {(`xA,El
try{ h&t9CpTfeJ
if(ps!=null) { +dK;\wT
ps.clearParameters(); '$be+Z32
ps.close(); 7Dx<Sr!
ps=null; E`UEl$($
} Gn?<~8a
}catch(SQLException e){} k*= #XbX
DBUtils.closeConnection(conn); @RI\CqFHR
} RD'i(szi?
} 'sTMUPg`
public long getLast(){ J]4Uh_>)
return lastExecuteTime;
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} 8|\?imOp\[
public void run(){ t9m08K:Y
long now = System.currentTimeMillis(); H5p&dNO
if ((now - lastExecuteTime) > executeSep) { g=n /w
//System.out.print("lastExecuteTime:"+lastExecuteTime); =xsTVT;sj
//System.out.print(" now:"+now+"\n"); Q|:qs\6q5
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); ]kyGm2Ty9
lastExecuteTime=now; Fop'm))C8
executeUpdate(); vBjrI*0
} wO ?A/s
else{ ."JtR
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); %$SO9PY
} [NIaWI,>
} +d,Z_ 6F
} 0N>R!
//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 l)(
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类写好了,下面是在JSP中如下调用。 Kh2!c+Mw
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<% RL3G7 ;X
CountBean cb=new CountBean(); la[>C:8IG
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); A"~4|`W
CountCache.add(cb); {Zy)p%j8
out.print(CountCache.list.size()+"<br>"); MFm2p?zPm
CountControl c=new CountControl(); <ULydBom
c.run(); 'z3I*[!
out.print(CountCache.list.size()+"<br>"); +OC~y:
%>