Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Yy~xNj5OS
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 L@'2}7N1%
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 w~_ycY.e
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分页支持类: b*W,8HF 4,
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java代码: \K9.]PfbI
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package com.javaeye.common.util; ySI}Nm>&=
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import java.util.List; ZeY|JH1
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publicclass PaginationSupport { |)xWQ KzA
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publicfinalstaticint PAGESIZE = 30; xbxzB<yL
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privateint pageSize = PAGESIZE; JB%_&gX)v
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privateList items; Tay$::V
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privateint totalCount; /NjBC[P
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privateint[] indexes = newint[0]; m]*a;a'}#
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privateint startIndex = 0; R:(i}g<3
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public PaginationSupport(List items, int dl3;A_ 2
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totalCount){ k q]E@tE*3
setPageSize(PAGESIZE); ?w!8;xS8
setTotalCount(totalCount); j!kJ@l bP
setItems(items); /}2Y-GOU
setStartIndex(0); Kxa1F,dZ
} #_x5-?3
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public PaginationSupport(List items, int r~JGs?GH
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totalCount, int startIndex){ ,\X! :y~
setPageSize(PAGESIZE); @)0
setTotalCount(totalCount); aeI0;u
setItems(items); [3qH?2&
setStartIndex(startIndex); livKiX`
} 2LR y/ah
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public PaginationSupport(List items, int !q,7@W3i
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totalCount, int pageSize, int startIndex){ ^|zag
setPageSize(pageSize); 7sQHz.4
setTotalCount(totalCount); cr<j<#(Z}
setItems(items); iPV-w_HQ
setStartIndex(startIndex); 2}XRqa.|
} AG}j'
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publicList getItems(){ E:M,nSc)53
return items; <`"
} +TA~RCd
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publicvoid setItems(List items){ F .Zk};lb
this.items = items; Q0Do B
} i/n
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publicint getPageSize(){ 3M+rFB}tS
return pageSize; gm,AH85
} ME0u|_dPjz
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publicvoid setPageSize(int pageSize){ 9XtO#!+48
this.pageSize = pageSize; -C(Yl=
} jSHFY]2
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publicint getTotalCount(){ L~)8Q(f
return totalCount; +>1?ck
} &+@`Si=
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publicvoid setTotalCount(int totalCount){ %{4U\4d@'
if(totalCount > 0){ ?B;7J7 T
this.totalCount = totalCount;
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int count = totalCount / 8rS;}Bt
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pageSize; bo90;7EK8
if(totalCount % pageSize > 0) `:~Wu/Ogr
count++; x:~XZX\mwH
indexes = newint[count]; et~D9='E
for(int i = 0; i < count; i++){ XD8I.q
indexes = pageSize * SPdEO3
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i; 'Ca;gi !U
} Rh)XYCM
}else{ R31Z(vY
this.totalCount = 0; 5EVypw?]x
} o$;&q
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} &}Wi@;G]2
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publicint[] getIndexes(){ sT!?nn3O`
return indexes; ?)(/SZC0
} "u4x#7n|
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publicvoid setIndexes(int[] indexes){ j2IK\~W?-
this.indexes = indexes; sCY
} 56c[$ q
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publicint getStartIndex(){ {*hvzS{1d
return startIndex; L-}Uj^yF
} ;T0X7MNx
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publicvoid setStartIndex(int startIndex){ ?qSwV.l]d
if(totalCount <= 0) T6\]*mlr
this.startIndex = 0; |:#Ug
elseif(startIndex >= totalCount) Z?=o(hkd
this.startIndex = indexes CYE[$*g6y
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[indexes.length - 1]; yF6AI@y
elseif(startIndex < 0) nIlTzrf6
this.startIndex = 0; Da8gOZ
else{ oLX[!0M^
this.startIndex = indexes N;-%:nC
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[startIndex / pageSize]; %{ rb,6
} HbB8A#u
} mejNa(D ^
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publicint getNextIndex(){ oGI'a:iff
int nextIndex = getStartIndex() + GJQ>VI2cY
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pageSize; U*yOe*>
if(nextIndex >= totalCount) S!$S'{f<
return getStartIndex(); `w>D6K+
else B?^~1Ua9Zv
return nextIndex; rX5"p!z
} RR+kjK?
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publicint getPreviousIndex(){ y O@1#
int previousIndex = getStartIndex() - 4<PupJ
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pageSize; JtMl/h
if(previousIndex < 0) L'KKU4zj
return0; 5+oY c-
else f2o6GC_
return previousIndex; C|IHRw`[
} Rsq EAdZw[
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}
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抽象业务类 _](y<O^9yO
java代码: +eH`mI0f
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/** h~qvd--p0
* Created on 2005-7-12 <<gW`KF
*/ [Rq|;p
package com.javaeye.common.business; "'Gq4<&y
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import java.io.Serializable; tQT<1Q02i
import java.util.List; ZRw^<
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import org.hibernate.Criteria; u\@Qze
import org.hibernate.HibernateException; bxL'k/Y$
import org.hibernate.Session; )Kl@dj
import org.hibernate.criterion.DetachedCriteria; FcZ)^RQ4G
import org.hibernate.criterion.Projections; ]lyQ*gM
import k^;/@:
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org.springframework.orm.hibernate3.HibernateCallback; AEWrrE
import C{t}q*fG
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org.springframework.orm.hibernate3.support.HibernateDaoS rbv
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upport; &Y9%Y/Y
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import com.javaeye.common.util.PaginationSupport; wfu`(4
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public abstract class AbstractManager extends LB$0'dZU
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HibernateDaoSupport { z$g__q-
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privateboolean cacheQueries = false; f0%'4t
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privateString queryCacheRegion; x+'Ea.^
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publicvoid setCacheQueries(boolean q`z1ht
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cacheQueries){ >XuPg(Ow
this.cacheQueries = cacheQueries; j3+ hsA/(k
} ~SA>$
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publicvoid setQueryCacheRegion(String 9-1'jNV
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queryCacheRegion){ B
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this.queryCacheRegion = x|^p9m"=%
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queryCacheRegion; T(cpU,Q
} ?wIEXKI
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publicvoid save(finalObject entity){ #X{lV]Z
getHibernateTemplate().save(entity); 3aU4Z|f~
} &!'R'{/?X
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publicvoid persist(finalObject entity){ _]3#C[1L
getHibernateTemplate().save(entity); C4-%|+Q i
} :Us+u-~
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publicvoid update(finalObject entity){ w; f LnEz_
getHibernateTemplate().update(entity); z<yqQ[
} {Ov{O,c5
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publicvoid delete(finalObject entity){ iM8l,Os]<f
getHibernateTemplate().delete(entity); n{m[
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} Fs=E8' b
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publicObject load(finalClass entity, 1^WkW\9kO
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finalSerializable id){ vr
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return getHibernateTemplate().load x;STt3M~
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(entity, id); \K
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} 6mIRa(6V
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publicObject get(finalClass entity, WE
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finalSerializable id){ bK!uR&i^l
return getHibernateTemplate().get =%[vHQ\%
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(entity, id); A- #c1KU!
} UH5A;SrTqR
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publicList findAll(finalClass entity){ |B\76Nk
return getHibernateTemplate().find("from `Q>qmf_Fi
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" + entity.getName()); QT(]S>--n
} Jb7^'P
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publicList findByNamedQuery(finalString [F,s=,S'M
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namedQuery){ 5N2`e3:I
return getHibernateTemplate _Vt
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().findByNamedQuery(namedQuery); S<w?,Z
} a{kLAx[>
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publicList findByNamedQuery(finalString query, S\2@~*{-8
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finalObject parameter){ FeZGPxc~
return getHibernateTemplate [ofZ1hB4
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().findByNamedQuery(query, parameter); )u=a+T
} Uee$5a>(
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publicList findByNamedQuery(finalString query, <x:^w'V_b
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finalObject[] parameters){ ,Q+.kAh !G
return getHibernateTemplate 2)|G%f_lS
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().findByNamedQuery(query, parameters); !z+'mF?V+X
} .fNLhyd
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publicList find(finalString query){ {jEEAH)
return getHibernateTemplate().find 6dqI{T-i?
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(query); lnrs4s Km
} i#Z#(D
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publicList find(finalString query, finalObject )H*BTfmt
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parameter){ m]ALW0
return getHibernateTemplate().find :io[9B [
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(query, parameter); A 1aN<!ehB
} {6>:=?7]R
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public PaginationSupport findPageByCriteria 7k#0EhN 1>
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(final DetachedCriteria detachedCriteria){ 7vB6IF
return findPageByCriteria -dH]_
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 3^Z@fC
} HurF4IsHk
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public PaginationSupport findPageByCriteria )C0 y<:</
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(final DetachedCriteria detachedCriteria, finalint 3q0S}<h al
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startIndex){ C=P}@| K
return findPageByCriteria 0
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(detachedCriteria, PaginationSupport.PAGESIZE, '],G!U(
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startIndex); 6@=ipPCR
} ST[E$XL6
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public PaginationSupport findPageByCriteria UZ7ukn-
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(final DetachedCriteria detachedCriteria, finalint (bGk=q=M
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pageSize, j%fi*2uX
finalint startIndex){ -}"nb-RR\
return(PaginationSupport) ]oyWJ#8
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getHibernateTemplate().execute(new HibernateCallback(){ a- 7RJ.
publicObject doInHibernate 7$Pf
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(Session session)throws HibernateException { C$`^(?iO/
Criteria criteria = <l$ vnq
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detachedCriteria.getExecutableCriteria(session); OA&r8WK3
int totalCount = Z#s-(wf
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((Integer) criteria.setProjection(Projections.rowCount ,?VYrL
t7,** $ST
()).uniqueResult()).intValue(); :<,tGYg/!
criteria.setProjection M~g@y$
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(null); *!`bC@E
List items = K,H xe;-
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criteria.setFirstResult(startIndex).setMaxResults <(BIWm*
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(pageSize).list(); <|VV8r93
PaginationSupport ps = /F}dC/W
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new PaginationSupport(items, totalCount, pageSize, DU:+D}vl
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startIndex); q`HK4~i,
return ps; -
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} f!JSb?#3
}, true); , 4@C %
} {1'M76T
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public List findAllByCriteria(final %TzdpQp"
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DetachedCriteria detachedCriteria){ >&)|fV&4
return(List) getHibernateTemplate +(oExp(!
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().execute(new HibernateCallback(){ QMwV6cA
publicObject doInHibernate u\=yY.
*.+N?%sAP)
(Session session)throws HibernateException { W7.QK/@
Criteria criteria = ^6 \@$
(o1o);AO
detachedCriteria.getExecutableCriteria(session); 4J$dG l#f
return criteria.list(); 2jyxP6t
} TGI`}#
}, true); +xBM\Dz8
} 1"U.-I@
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public int getCountByCriteria(final _j|U>s
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DetachedCriteria detachedCriteria){ 6R!AIOD>
Integer count = (Integer) (+;%zh-
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getHibernateTemplate().execute(new HibernateCallback(){ Ej'N!d.
publicObject doInHibernate +$B#] ,
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(Session session)throws HibernateException { M/jdMfU
Criteria criteria = =[`gfw
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detachedCriteria.getExecutableCriteria(session); oNRp
return y(jd$GM|
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criteria.setProjection(Projections.rowCount ivPX_#QI
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()).uniqueResult(); ;ZR^9%+y9
} ybpU?n
}, true); {AAi x
return count.intValue(); J24H}^~na
} )!d_Td\-
} &F|Wk,y
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用户在web层构造查询条件detachedCriteria,和可选的 !tuK.?q|l
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startIndex,调用业务bean的相应findByCriteria方法,返回一个
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PaginationSupport的实例ps。 =<z~OE'lV
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ps.getItems()得到已分页好的结果集 /P/::$
ps.getIndexes()得到分页索引的数组 =B
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ps.getTotalCount()得到总结果数 A9M/n^61
ps.getStartIndex()当前分页索引 _OR[RGy
ps.getNextIndex()下一页索引 /{nZI_v#
ps.getPreviousIndex()上一页索引 k 1;Jkq~
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 |sV@j_TX
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 l[{Ci|4
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一下代码重构了。 Z%I9:(
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我把原本我的做法也提供出来供大家讨论吧: WvHy}1W
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首先,为了实现分页查询,我封装了一个Page类: T( sEk
java代码: 0/?=FM>
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/*Created on 2005-4-14*/ Y'M}lv$sa
package org.flyware.util.page; _@ @"'
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/** ;#6j9M0
* @author Joa s&Qil07Vl
* {$^Lb4O[V
*/ Ix'GP7-m_
publicclass Page { ($:JI3e[;
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/** imply if the page has previous page */ 407;M%?'A
privateboolean hasPrePage; |Xa|%f
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/** imply if the page has next page */ >rzpYc'~w
privateboolean hasNextPage; [:C!g#o
<