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: lsCD%P
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CountBean.java A-aukJg9
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/* ;J Dn1(6
* CountData.java ^*#5iT8/
* tj;<Z.
* Created on 2007年1月1日, 下午4:44 w6+X{
* :/c=."z.
* To change this template, choose Tools | Options and locate the template under PaP47>(
* the Source Creation and Management node. Right-click the template and choose \|BtgT *$b
* Open. You can then make changes to the template in the Source Editor. B_i@D?bTD
*/ |lm
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package com.tot.count; lsU|xOB
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/** jY-{hW+r
* s+YQ
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* @author u3(zixb
*/ Q@6OIE
public class CountBean { G4{ zt3{
private String countType; PCF!Y(l
int countId; B4bC6$Lg
/** Creates a new instance of CountData */ *>h"}e41
public CountBean() {} p 2It/O
public void setCountType(String countTypes){ wqx@/--E(
this.countType=countTypes; "X4OUk
} c}kZx1
public void setCountId(int countIds){ A1Ia9@=Mf
this.countId=countIds; S75wtz)e
} hn{]Q@(I
public String getCountType(){ >0~|iRySi
return countType; r&@#,g
} \< <u
public int getCountId(){ 1q0DOf]!T
return countId; RJYuyB
} fdc
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} 'e^,#L_!o
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CountCache.java }26?bd@e`
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/* ;XNe:g.CR
* CountCache.java +[:"$?J
* Qz2Yw `
* Created on 2007年1月1日, 下午5:01 !4\`g?
* Eqc&iS~
* To change this template, choose Tools | Options and locate the template under TCYjj:/
* the Source Creation and Management node. Right-click the template and choose -lV]((I&
* Open. You can then make changes to the template in the Source Editor. G7yCGT)vQ
*/ lyNa(3
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package com.tot.count; _)
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import java.util.*; 3 GmU$w
/** [g`9C!P-G
* X<dQq`kZ
* @author `CA-s
*/ ^\Tde*48
public class CountCache { P+ONQN|
public static LinkedList list=new LinkedList(); j|gQe .,1
/** Creates a new instance of CountCache */ 28[hp[<
public CountCache() {} VHwb 7f]gq
public static void add(CountBean cb){ 3/>T/To&2
if(cb!=null){ !G=!^RA
list.add(cb); vM!lL6T:
} #_0OYL`(mE
} (JHzwI8+
} =>#
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CountControl.java ?$i`K|
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/* ^BIB'/Kh)
* CountThread.java [y-0w.V=oE
* Nd'+s>d0
* Created on 2007年1月1日, 下午4:57 XdE#l/#
* M}=X/*T
* 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 S+Z_Qf
* Open. You can then make changes to the template in the Source Editor. >a7OE=K
*/ 8dgI&t
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package com.tot.count; JJ`RF
import tot.db.DBUtils; ;U=IbK*
import java.sql.*; Bd jo3eX
/** *@/1]W
* 1Q"w)Ta
* @author R#gt~]x6k
*/ nt.A X
public class CountControl{ Q%)da)0:c
private static long lastExecuteTime=0;//上次更新时间 #$7d1bx
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 Xu\FcQ{
/** Creates a new instance of CountThread */ 12qX[39/
public CountControl() {} lx_jy>$}r
public synchronized void executeUpdate(){ vVB8zS~l
,
Connection conn=null; {:BAh5e|
PreparedStatement ps=null; uJ<nW%}
try{ lVF}G[B
conn = DBUtils.getConnection(); "#1KO1@G
conn.setAutoCommit(false); V'?bZcRr~
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); "[M,PI!B
for(int i=0;i<CountCache.list.size();i++){ GcN[bH(@
CountBean cb=(CountBean)CountCache.list.getFirst(); :EJ8^'0Q
CountCache.list.removeFirst(); -kFEVJbUyc
ps.setInt(1, cb.getCountId()); WO$9Svh8
ps.executeUpdate();⑴ M"# >?6{
//ps.addBatch();⑵ x&}pM}ea
} "2} {lu
//int [] counts = ps.executeBatch();⑶ <%w)EQf4m
conn.commit(); qd$Y"~Mco
}catch(Exception e){ eGcc' LBr;
e.printStackTrace(); F]o&m::/K
} finally{ K8`Jl=}z%&
try{ [ u7p:?WDW
if(ps!=null) { +e
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ps.clearParameters(); E_sKD ybj
ps.close(); -OV:y],-
ps=null; \yt-_W=[
} (Z(O7X(/
}catch(SQLException e){} N3/G6wn
DBUtils.closeConnection(conn); `w/:o$&
} FvpaU\D
} .axJ '*~W
public long getLast(){ 7>
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return lastExecuteTime; 6zv-nMZc
} ' cM2]<
public void run(){ Nl"Xl?y}
long now = System.currentTimeMillis(); ;MRK*sfw{
if ((now - lastExecuteTime) > executeSep) { =AEl:SY+
//System.out.print("lastExecuteTime:"+lastExecuteTime); .quui\I3
//System.out.print(" now:"+now+"\n"); U`YPzZp_
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); 99W-sV
lastExecuteTime=now; pc9m,?n
executeUpdate(); t!}QG"ma
} #?=?<"*j
else{ yTt,/+I%gJ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); q8&2M
} j"G1D-S:
} [I6(;lq2
} ~)J]`el,Q
//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 R(YhVW_l
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类写好了,下面是在JSP中如下调用。 Tfasry9'8
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<% M"XILNV-~
CountBean cb=new CountBean(); poLzgd
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 9Q\CJ9
CountCache.add(cb); 4wLN#dpeEy
out.print(CountCache.list.size()+"<br>"); 5:S=gARz
CountControl c=new CountControl(); q{4W@Um-
c.run(); BY*{j&^
out.print(CountCache.list.size()+"<br>"); `Wc"Ix0
%>