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: hb="J349
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CountBean.java -g\ ;B
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/* ` G-V
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* CountData.java >h3m/aeNC
* scQnL'\
* Created on 2007年1月1日, 下午4:44 iO@UzD#v
* RzOcz=A}
* To change this template, choose Tools | Options and locate the template under tN1xZW:
* the Source Creation and Management node. Right-click the template and choose zN3b`K. i
* Open. You can then make changes to the template in the Source Editor. L'L[Vpx
*/ !YVGT
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package com.tot.count; A~)#
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/** %iR"eEE
* a${<~M
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* @author ^gSZzJ5
*/ $+
public class CountBean { N> jQe
private String countType; C116c"
int countId; Q5xQ5Le
/** Creates a new instance of CountData */ Ek6z[G`
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public CountBean() {} %5$)w;p.$'
public void setCountType(String countTypes){ 9y+0Zj+.
this.countType=countTypes; 38E
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} ;_p$5GVR|
public void setCountId(int countIds){ L.?QZN%cN
this.countId=countIds; ;V0^uB.z
} yQ!I`T>a
public String getCountType(){ <q.Q,_cW
return countType; ?>/9ae^Bw
} >r\q6f#J4
public int getCountId(){ `F`{s`E)
return countId; L6x;<gj
} #1De#uZ
} giYlLJA*}
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CountCache.java 8AQ__&nT
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/* H@!]5 <:9
* CountCache.java `nrw[M?
* 10d.&vNw
* Created on 2007年1月1日, 下午5:01 z5p5=KOb
* |i\%>Y,
* To change this template, choose Tools | Options and locate the template under Mz 6PH)e;
* the Source Creation and Management node. Right-click the template and choose `Kbf]"4q
* Open. You can then make changes to the template in the Source Editor. ")YD~ZA%)
*/ =6'Fm$R
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package com.tot.count; cDIZkni=
import java.util.*; p1N3AhXY
/** bRD-[)
* GIZw/L7Yb
* @author Ge7Uety
*/ *3\*GatJ
public class CountCache { =Hbf()cN)
public static LinkedList list=new LinkedList();
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/** Creates a new instance of CountCache */ c!ieN9^+
public CountCache() {} 7epil
public static void add(CountBean cb){ t0_4jVt
if(cb!=null){ $p|Im,
list.add(cb); Z 4QL&?U
} />n!2'!
} $0Ys{m
} \ `;1[m
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CountControl.java "H#pN;)+
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/* GTM@9^
* CountThread.java " GY3sam
* !bs5w_@
* Created on 2007年1月1日, 下午4:57 [/o BjiBA
* z HT#bP:o
* To change this template, choose Tools | Options and locate the template under #/>
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* the Source Creation and Management node. Right-click the template and choose Z!-V&H.
* Open. You can then make changes to the template in the Source Editor. lK_T%1Gz
*/ y*
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package com.tot.count; 3rBID
import tot.db.DBUtils; q P0UcG
import java.sql.*; D"gv:RojD
/** C8W_f( i~
* OS-k_l L
* @author NvC @
*/ (8baa.ge
public class CountControl{ EU7nS3K)O~
private static long lastExecuteTime=0;//上次更新时间 0t[ 1#!=k
private static long executeSep=60000;//定义更新间隔时间,单位毫秒 EM(%|#
/** Creates a new instance of CountThread */ /dO*t4$ @?
public CountControl() {} @/,0()* dL
public synchronized void executeUpdate(){ .W\JvPTC
Connection conn=null; +%H=+fJ2}
PreparedStatement ps=null; &NOCRabc
try{ @?>5~
conn = DBUtils.getConnection(); W_6gV
conn.setAutoCommit(false); fA"c9(>m%]
ps=conn.prepareStatement("update t_news set hits=hits+1 where id=?"); Q zg?#|
for(int i=0;i<CountCache.list.size();i++){ Hy5 6@jW+E
CountBean cb=(CountBean)CountCache.list.getFirst(); n-g#nEc:
CountCache.list.removeFirst(); _Wq;bKG
ps.setInt(1, cb.getCountId()); *eGG6$I
ps.executeUpdate();⑴ Zv2]X-
//ps.addBatch();⑵ G5%k.IRz
} 8"TlWHF`
//int [] counts = ps.executeBatch();⑶ jn`5{ ]D
conn.commit(); #"8'y
}catch(Exception e){ z%BX^b$Hj
e.printStackTrace(); fR?'HsQg
} finally{ %}JSR y
try{ O0;mXH
if(ps!=null) { |qVM`,%L
ps.clearParameters(); =KAN|5yn
ps.close(); K4-_a{)/
ps=null; (|#%omLL
} MV w.Fl
}catch(SQLException e){} R13V}yL
DBUtils.closeConnection(conn); T(,@]=d,DD
} V>`9ey!U
} 5`@yX[G
public long getLast(){ ii&ckg>]z
return lastExecuteTime; 4]FS
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} [+8*}03
public void run(){ el\xMe^SY
long now = System.currentTimeMillis(); ]TJ258P}
if ((now - lastExecuteTime) > executeSep) { /E3~z0
//System.out.print("lastExecuteTime:"+lastExecuteTime); 'y5H%I!
//System.out.print(" now:"+now+"\n"); -?l`LbD
// System.out.print(" sep="+(now - lastExecuteTime)+"\n"); @-Y,9mM
lastExecuteTime=now; }u8g7Nj
executeUpdate(); @REMl~"D5
} B`gH({U
else{ #3tC"2MZ
//System.out.print("wait for "+(now - lastExecuteTime)+" seconds:"+"\n"); 0dQ\Y]b
} Z?d][zGw
} c[T@lz(!
} i9V,
//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 c$lZ\r"
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类写好了,下面是在JSP中如下调用。 .s?^y+e_
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<% _[Sh`4`r
CountBean cb=new CountBean(); :Gzp
(@<@e
cb.setCountId(Integer.parseInt(request.getParameter("cid"))); f]mVM(XZN
CountCache.add(cb); cj^hwtx
out.print(CountCache.list.size()+"<br>"); 9Fw NX
CountControl c=new CountControl(); 0x<G\ l4
c.run(); Q5l+-
out.print(CountCache.list.size()+"<br>"); %eh.@8GL`
%>