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: :+<t2^)rD
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CountBean.java xg{VP7
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/* G~`'E&/
* CountData.java U-1VnX9m
* %kJh6J
* Created on 2007年1月1日, 下午4:44 nZ541o@t9
* xl|ghjn
* To change this template, choose Tools | Options and locate the template under $\0TD7p
* the Source Creation and Management node. Right-click the template and choose OCwW@OC +
* Open. You can then make changes to the template in the Source Editor. qT"drgpi3
*/ R/Tj^lM
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package com.tot.count; x<Iy<v7-
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/** 0c`sb+?
* fJvr+4i4k
* @author -*r [
*/ (I>HWRH
public class CountBean { prqyoCfq
private String countType; >eEnQ}Y
int countId; F9F" F
/** Creates a new instance of CountData */ 3>H2xh 3Y
public CountBean() {} Tw}@+-
public void setCountType(String countTypes){ G2=F8kL
this.countType=countTypes; D8gQRQ
} ?U}sQ;c$
public void setCountId(int countIds){ 9)jo7,VM
this.countId=countIds; @>+^W&
} ,n^TN{#
public String getCountType(){ YfV"_G.ad|
return countType; @;g`+:=
} 23)F-.C}j
public int getCountId(){ E1^aAlVSD
return countId; (_s;aK
} o*?[_{xW
} }Q,(u
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CountCache.java BvSdp6z9Iv
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/* ~K4k'
* CountCache.java $,}Qf0(S
* 7zOhyl?
* Created on 2007年1月1日, 下午5:01 h_AJI\{"
* #8S [z5 `
* To change this template, choose Tools | Options and locate the template under 2;dM:FHLhO
* the Source Creation and Management node. Right-click the template and choose 7qW.h>%WE
* Open. You can then make changes to the template in the Source Editor. u![4=w
*/ FP.(E9
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package com.tot.count; H<v c\r
import java.util.*; |*lH9lWJ
/** yBr$ 0$
* Q~x*bMb.
* @author 37%`P\O;s
*/ >|v=Ba6R0
public class CountCache { zNNzsT8na
public static LinkedList list=new LinkedList(); eL>K2Jxq
/** Creates a new instance of CountCache */ Z'voCWCd
public CountCache() {} bMSD/L
public static void add(CountBean cb){ 8W(<q|t
if(cb!=null){ w g$D@E7
list.add(cb); ac2}3$u
} OJnPP>
} rd|@*^k
} bv .EM
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CountControl.java emGV]A%nss
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/* $ iX^p4v
* CountThread.java oc!biE`u
* Z)C:]}Ex
* Created on 2007年1月1日, 下午4:57 zyIza @V(
* ;m-6.AV
* To change this template, choose Tools | Options and locate the template under ~5-~q0Ge
* the Source Creation and Management node. Right-click the template and choose pP?<[ql[w
* Open. You can then make changes to the template in the Source Editor. *5ka.=Qs
*/ *O2^{ C
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package com.tot.count; cRs{=RGc
import tot.db.DBUtils; c.|sW2/
import java.sql.*; 8Uj68Jl?
/** {LR#(q$1
* 6|B a
* @author U)&H.^@r$
*/ $M:4\E5(
public class CountControl{ uYG #c(lc
private static long lastExecuteTime=0;//上次更新时间 )_Z]=5Ds
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 BsoFQw4$9
/** Creates a new instance of CountThread */ + TPbIRA
public CountControl() {} >WGX|"!"
public synchronized void executeUpdate(){ 'US:Mr3
Connection conn=null; aRFi0h
\
PreparedStatement ps=null; ucIVVT(u
try{ ;g;,%jdCS
conn = DBUtils.getConnection(); 4<=eK7;XR
conn.setAutoCommit(false); 34&u]4=L)
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); V Z4nAG
for(int i=0;i<CountCache.list.size();i++){ mafAC73
CountBean cb=(CountBean)CountCache.list.getFirst(); 8eg2o$k_,#
CountCache.list.removeFirst(); 17MN8SfQ
ps.setInt(1, cb.getCountId()); )W_ Y3M,
ps.executeUpdate();⑴ `R4W4h'I
//ps.addBatch();⑵ z/c'Z#w%
} KDNTnA1c
//int [] counts = ps.executeBatch();⑶ KD[)O7hYC
conn.commit(); *@b~f&Lx6
}catch(Exception e){ hW*^1%1
e.printStackTrace(); 7v4-hfN
} finally{ Jgi{7J
try{ ex;Yn{4
if(ps!=null) { s+OvS9et_
ps.clearParameters(); LaAgoarN
ps.close(); .HH,l
ps=null; S4@117z5
} ~|$) 1
}catch(SQLException e){} \kua9bK
DBUtils.closeConnection(conn); xc3Ov9`8%
} %j
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} 7;$L&X
public long getLast(){ bUipp\[aV
return lastExecuteTime; HbJadOK
} ;&7qw69k
public void run(){ .{-iq(3
long now = System.currentTimeMillis(); JsAb q
if ((now - lastExecuteTime) > executeSep) { YQfZiz}Fv
//System.out.print("lastExecuteTime:"+lastExecuteTime); LiHXWi{s
//System.out.print(" now:"+now+"\n"); r`mzsO-'
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); +ik N) D
lastExecuteTime=now; 9I^H)~S
executeUpdate(); S%a}ip&
} 9v5.4a}
else{ ]9~#;M%1
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); A7I8Z6&
} 7@e[:>e
} %o SfL;W7
} j3V"d 3)
//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[ +]d|L
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类写好了,下面是在JSP中如下调用。 do:RPZ!
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<% Bt`r6v;\
CountBean cb=new CountBean(); /M{)k_V
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); 7\Yq]:;O
CountCache.add(cb); &`\kb2uep
out.print(CountCache.list.size()+"<br>"); l#J>It\
CountControl c=new CountControl(); $D2Ain1
c.run(); *(XgUJq+
out.print(CountCache.list.size()+"<br>"); c+\Gd}IJq
%>