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: XOEf,"
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CountBean.java d/E0opv
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/* cN)noGkp
* CountData.java H+Q_%%[N
* &CfzhIi*!
* Created on 2007年1月1日, 下午4:44 XL(2Qk
* tz2$j@!=
* To change this template, choose Tools | Options and locate the template under /q^_
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* the Source Creation and Management node. Right-click the template and choose `U{#;
* Open. You can then make changes to the template in the Source Editor. w^S]HzMd
*/ :{?Pq8jP
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package com.tot.count; YwJ<0;:+hS
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/** UQjZhH
* RI]x=
* @author $EZr@n
*/ h5[.G!
public class CountBean { ^_o:Ddz?l"
private String countType; '@#l/9
int countId; ={~A}
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/** Creates a new instance of CountData */ dz?Ey~;M
public CountBean() {} Ev&aD
public void setCountType(String countTypes){ ^1XnnQa
this.countType=countTypes; ~bfjP2
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} R#/0}+-M
public void setCountId(int countIds){ Qa1G0qMEIF
this.countId=countIds; Vje LPbk)
} &lW~ot1,
public String getCountType(){ P2 +^7x?
return countType; xic&m5j
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} Q5;EQ.#
public int getCountId(){ ?<soX8_1
return countId; L(BL_
} AUR{O
} 5ma~Pjt8}
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CountCache.java g+=f=5I3
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/* 2X=*;r"{J
* CountCache.java 9tB:1n}
* 'zQp64]F
* Created on 2007年1月1日, 下午5:01 Y>K3.*.
* q)]S:$?BT
* To change this template, choose Tools | Options and locate the template under @ oFuX.
* the Source Creation and Management node. Right-click the template and choose ] -G~
* Open. You can then make changes to the template in the Source Editor. gR k+KGKn<
*/ _"qX6Jc
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package com.tot.count; h8HA^><Xr
import java.util.*; z4(Q.0x7
/** \p!mX|
* #:nds,
* @author {^Q1b.=
*/ R<ZyP~
public class CountCache { "C]_pWk
public static LinkedList list=new LinkedList(); Fh ^Ax3P(
/** Creates a new instance of CountCache */ Mj:=$}rs^
public CountCache() {} Tc;j)_C)
public static void add(CountBean cb){ lLuAg ds`
if(cb!=null){ YGkk"gFIA
list.add(cb); :4S~}}N
} wTVd){q`.
} .4,l0Nn`W
} Ga$EM
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CountControl.java OyTp^W`&
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/* gK-$y9]~+
* CountThread.java fvw&y+|y!
* hgF4PdO1e
* Created on 2007年1月1日, 下午4:57 'M3V#5l)@|
* BxGz4
* To change this template, choose Tools | Options and locate the template under M\be a
* the Source Creation and Management node. Right-click the template and choose wTu=v
* Open. You can then make changes to the template in the Source Editor. ~@EBW3>~5
*/ X:gE
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package com.tot.count; _iW-i
import tot.db.DBUtils; 9rQw~B<S
import java.sql.*; )Xd2qbi
/** sqk$q pV6
* .k:Uj-&
* @author T\$r|
*/ |%7OI#t^
public class CountControl{ DX@*lM
private static long lastExecuteTime=0;//上次更新时间 /N\[ C"8
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 uHpSE?y/
/** Creates a new instance of CountThread */ Ke,$3Yx
public CountControl() {} ='GY:. N
public synchronized void executeUpdate(){ @`#"6y?
Connection conn=null; >,QW74o
PreparedStatement ps=null; _;`g*Kx
try{ hS:j$je
conn = DBUtils.getConnection(); $61*X f+*
conn.setAutoCommit(false); #
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ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); *heX[D
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for(int i=0;i<CountCache.list.size();i++){ wUbLw
CountBean cb=(CountBean)CountCache.list.getFirst(); >EIV`|b$h
CountCache.list.removeFirst(); 9Y-6e0B:
ps.setInt(1, cb.getCountId()); RF.8zea{O`
ps.executeUpdate();⑴ "ku ?A ^f
//ps.addBatch();⑵ P
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} 5nJmabw3
//int [] counts = ps.executeBatch();⑶ XKT2u!Lx
conn.commit(); L#NW<T
}catch(Exception e){ X| X~|&j
e.printStackTrace(); vd!|k5t[d
} finally{ $4*k=+wS
try{ z9[BQ(9t
if(ps!=null) { 4?9cyv4H
ps.clearParameters(); 4+_r0
ps.close(); }@S''AA\
ps=null; ~V<62"G
} L
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}catch(SQLException e){} 0'.7dzz
DBUtils.closeConnection(conn); YkbZ 2J*-
} (xhV>hsA
} dGBVkb4]T
public long getLast(){ >J
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return lastExecuteTime; Af _yb`W?
} q(cSHHv+
public void run(){ W-ll2b
long now = System.currentTimeMillis(); #-Nc1+gu
if ((now - lastExecuteTime) > executeSep) { >@NGX-gp
//System.out.print("lastExecuteTime:"+lastExecuteTime); EkE U}2
//System.out.print(" now:"+now+"\n"); pUXszPf
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); nXnO]wXC
lastExecuteTime=now; G Za<
executeUpdate(); Y>: e4Q
} p[M*<==4
else{ F),wj8#~>-
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 5W=jQ3 C
} &fYV FRVkq
} .kkrU
} KQ(7% W
//注:如果你的数据库驱动支持批处理,那么可以将⑵,⑶标记的代码前的注释去掉,同时在代码⑴前加上注释 >X!A/;$
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类写好了,下面是在JSP中如下调用。 V[N4 {c
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<% lGAKHCs
CountBean cb=new CountBean(); />\6_kT
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); |ydOi&
CountCache.add(cb); >*aqYNft
out.print(CountCache.list.size()+"<br>"); 9F^rXY.
CountControl c=new CountControl(); A#P]|i
c.run(); oDEvhNT
out.print(CountCache.list.size()+"<br>"); YjM_8@<
%>