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: ],_+J*
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CountBean.java h5SJVa
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/* u\V^g
* CountData.java 3pg=9*{
* *,mI=1
* Created on 2007年1月1日, 下午4:44 <+k"3r{y"
* ak7kb7 5o
* To change this template, choose Tools | Options and locate the template under 8l_M 0F,
* the Source Creation and Management node. Right-click the template and choose ')U~a
* Open. You can then make changes to the template in the Source Editor. MB!9tju
*/ zcKQD )]
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package com.tot.count; Dn6U8s&
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/** o:D,,MkSw
* O&1qL)
* @author _bGkJ=
*/ 12a`,~
public class CountBean { @^A5{qQ\
private String countType; qT48Y
int countId; oQ 2$z8
/** Creates a new instance of CountData */ )rq |t9kix
public CountBean() {} MC* Hl`C
public void setCountType(String countTypes){ ^cm]
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this.countType=countTypes; ZUHRATT-
} 7~SwNt,
public void setCountId(int countIds){ 0?<#!
this.countId=countIds; z$e6T&u5B
} Pg%9hejf3
public String getCountType(){ V&w2pp0
return countType; 7~ PL8
} 2 %dL96
public int getCountId(){ &}r"Z?f)
return countId; fes s6=k
} b,Oh8O;>
} N7?B"p/
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CountCache.java G18w3BFx
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/* O\6U2b~
* CountCache.java _dJ(h6%3
* 5J10S
* Created on 2007年1月1日, 下午5:01 SVZocTt
* v1TFzcHl<
* To change this template, choose Tools | Options and locate the template under Ho>Np&
* the Source Creation and Management node. Right-click the template and choose r- <O'^C
* Open. You can then make changes to the template in the Source Editor. dE7S[O
*/ ^U}k
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package com.tot.count; u=
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import java.util.*; .\n` 4A1z
/** +n)n6}S
* T.4&P#a1
* @author m1l6QcT1
*/ U[@y8yN6M
public class CountCache { Dwp,d~z
public static LinkedList list=new LinkedList(); m^k0j/
/** Creates a new instance of CountCache */ !y= R)k
public CountCache() {} -QrC>3xZR
public static void add(CountBean cb){ V)j[`,M:
if(cb!=null){ -L1785pB85
list.add(cb); T3X'73M
} wDJ`#"5p{
} *yu}e)(0
} =]Vz=<
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CountControl.java
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/* FACw;/rW
* CountThread.java Y@Uk P+{f=
* j3gDGw;
* Created on 2007年1月1日, 下午4:57 UEU/505
* =dmr,WE
* To change this template, choose Tools | Options and locate the template under T5(S2^)o
* the Source Creation and Management node. Right-click the template and choose iwotEl0*{
* Open. You can then make changes to the template in the Source Editor. ,`@pi@<"#
*/ 7?$?Yu
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package com.tot.count; ={qcDgn~C
import tot.db.DBUtils; Zt `Tg7m
import java.sql.*; 4:`D3
/** D 2X_Yv
* xN 1P#
* @author O
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*/ ,/42^|=Z6O
public class CountControl{ /Mqhx_)>A
private static long lastExecuteTime=0;//上次更新时间 9iA rBL"
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 K^Awf6%
/** Creates a new instance of CountThread */ 0l!#u`cCI
public CountControl() {} Cn{Hk)6
public synchronized void executeUpdate(){ l":W@R
Connection conn=null; Ri. tA
PreparedStatement ps=null; #BC"bY
try{ LeKovt%
conn = DBUtils.getConnection(); &*C5Nnlv
conn.setAutoCommit(false); M]x>u@JH
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); x:|Y)Dn\
for(int i=0;i<CountCache.list.size();i++){ $x0SWJ \G
CountBean cb=(CountBean)CountCache.list.getFirst(); rUiYR]mV
CountCache.list.removeFirst(); Lc*>sOm9
ps.setInt(1, cb.getCountId()); <ql,@*Y
ps.executeUpdate();⑴ kT%wt1T4
//ps.addBatch();⑵ v}G^+-?
} '![oLy
//int [] counts = ps.executeBatch();⑶ *g/klK
conn.commit(); L:z0cvn"
}catch(Exception e){ p/.8})c1r
e.printStackTrace(); c{z$^)A/
} finally{ ;]{ee?Q^ld
try{ B,%Vy!o
if(ps!=null) { dY*q[N/pO
ps.clearParameters(); "mlQ z4D)5
ps.close(); @60D@Y
ps=null; sV\_DP/l
} d#k(>+%=Q
}catch(SQLException e){} t]/eCsR
DBUtils.closeConnection(conn); Nk|cU;?+
} j(;^XO Y#
} ,,H "?VO
public long getLast(){ d9N[f>
return lastExecuteTime; !?2)apM
} 8>Cr6m
public void run(){ K\Ea\b[
long now = System.currentTimeMillis(); p_FM 2K7!
if ((now - lastExecuteTime) > executeSep) { nhV"V`|d
//System.out.print("lastExecuteTime:"+lastExecuteTime); }^
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//System.out.print(" now:"+now+"\n"); &m5zd$6
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); U7r8FL l
lastExecuteTime=now; nbi7rcT
executeUpdate(); {o=?@ $6C
} NGx3f3 9
else{ 6TtB3;5
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); La4S/.
} v}B%:1P4
} } M#e\neii
} ,g*!NK_:5t
//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 S@qp_!
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类写好了,下面是在JSP中如下调用。 zLI0RI.Pe
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<% g'0CYY
CountBean cb=new CountBean(); 2MkrVQQ9g
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); ><V*`{bD9)
CountCache.add(cb); m,l/=M
out.print(CountCache.list.size()+"<br>"); O%bbyR2
CountControl c=new CountControl(); ajYe?z
c.run(); 9T,/R1N8
out.print(CountCache.list.size()+"<br>"); .tBlGMcN
%>