Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 9Vru,7g
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 j'k
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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 E<l/o5<nC
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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 |A/H*J,
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分页支持类: M!46^q~-
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java代码: iF9d?9TWl
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package com.javaeye.common.util; Cz)&R^
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import java.util.List; kO5lLqE
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publicclass PaginationSupport { WfD fj
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publicfinalstaticint PAGESIZE = 30; ^v`naA(
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privateint pageSize = PAGESIZE; `BQv;NtP
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privateList items; '4nJ*Xa
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privateint totalCount; 8IA1@0n&
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privateint[] indexes = newint[0]; (6.uNLr
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privateint startIndex = 0; 9vz\R-un
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public PaginationSupport(List items, int +J|H~`
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totalCount){ CxTmW5l
setPageSize(PAGESIZE); d=n@#|3
setTotalCount(totalCount); <sw@P":F
setItems(items); BZ=I/L
setStartIndex(0); 'L7qf'RV
} UXlZI'|He
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public PaginationSupport(List items, int VJ=>2'I
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totalCount, int startIndex){ ."H;bfcL_
setPageSize(PAGESIZE); #D4
setTotalCount(totalCount); &s='$a;4
setItems(items); z7ik/>d?
setStartIndex(startIndex); v !8=B21
} a8f#q]TyQ
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public PaginationSupport(List items, int \4L ur
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totalCount, int pageSize, int startIndex){ $uZmIu9Bi+
setPageSize(pageSize); *^uK=CH1?(
setTotalCount(totalCount); '< U&8?S
setItems(items); ,\s`T O
setStartIndex(startIndex); uhh7Ft#H
} J(l\VvK
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publicList getItems(){ d 2d-Mk
return items; SHX`/
} ^o{{kju
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publicvoid setItems(List items){ {5~h
this.items = items; H-PVV&r
} :$$~$P
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publicint getPageSize(){ oFj_o
return pageSize; KClkPL!jP
} (dq_,LI
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publicvoid setPageSize(int pageSize){ %):_
this.pageSize = pageSize; )&@YRT\c?8
} i%-yR DIX
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publicint getTotalCount(){ gx.\H3y
return totalCount; 2iG+Ek-?"
} ryL1<u
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publicvoid setTotalCount(int totalCount){ L5bq\
if(totalCount > 0){ ?6CLUu|7n
this.totalCount = totalCount; &DWSf`:Hx
int count = totalCount / M0w Uis:`
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pageSize; Wx:v~/r
if(totalCount % pageSize > 0) X"!j_*&ED
count++; 8"j $=T6;W
indexes = newint[count]; 9^XZ|`
for(int i = 0; i < count; i++){ :}e<
indexes = pageSize * ] 0X|_bU
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} TRi'l #m4
}else{ uppa`addK
this.totalCount = 0; y||
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} :^]Po$fl
} C~h#pAh
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publicint[] getIndexes(){ @rYZ0`E9
return indexes; OkciL]
} VeWh9:"bJ
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publicvoid setIndexes(int[] indexes){ ,7B7X)m{3
this.indexes = indexes; FEk9a^Xyx
} hoFgs9
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publicint getStartIndex(){ 2H`r:x<Z-
return startIndex; b$'%)\('g
} SD^::bH
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publicvoid setStartIndex(int startIndex){ vFe=AY<Rt|
if(totalCount <= 0) =8l' [
this.startIndex = 0; f!+d*9
elseif(startIndex >= totalCount) -U2Su|:\N8
this.startIndex = indexes spA|[\Nl
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[indexes.length - 1]; j0L%jz
elseif(startIndex < 0) NuO@Nr
this.startIndex = 0; GG#-x$jK
else{ t%mi#Gh(
this.startIndex = indexes ?*~
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[startIndex / pageSize]; U9]&KNx
} f4S}Nga(
} vVB WhY]
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publicint getNextIndex(){ 7oE:]
int nextIndex = getStartIndex() + dU-:#QV6
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pageSize; 2_Lu0Yrg
if(nextIndex >= totalCount) F42^Uoaz
return getStartIndex(); i`i`Hu>
else _Q #[IH9
return nextIndex; s3Bo'hGxG
} vmgd
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publicint getPreviousIndex(){ 6U).vg<
int previousIndex = getStartIndex() - l%V+]skS
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pageSize; *vNAm(\N
if(previousIndex < 0) 5#z7Hj&w
return0; vmxS^_I
else \V~B+e
return previousIndex; |xb;#ruR6
} E.C=VfBW
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} 3
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抽象业务类 ;Zf7|i`R3
java代码: G~zfPBN0D
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/** 2*W|s7cc
* Created on 2005-7-12 R<3 -!p1v
*/ $U&p&pgH=W
package com.javaeye.common.business; 1q
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import java.io.Serializable; P e}
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import java.util.List; (\'lV8}U
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import org.hibernate.Criteria; nBd(pOe
import org.hibernate.HibernateException; PE_JO(e;Xm
import org.hibernate.Session; [$]-W$j+
import org.hibernate.criterion.DetachedCriteria; 2Z9ck|L>
import org.hibernate.criterion.Projections; \^cXmyQ <%
import 1n)YCSA
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org.springframework.orm.hibernate3.HibernateCallback; )*}?EI4.
import c?Zi/7
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org.springframework.orm.hibernate3.support.HibernateDaoS N7q6pBA"E
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upport; l:a#B
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import com.javaeye.common.util.PaginationSupport; do.XMdit
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public abstract class AbstractManager extends ^%1u3
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HibernateDaoSupport { ;b|=osyT\
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privateboolean cacheQueries = false; }?CKE<#%
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privateString queryCacheRegion; ]<;y_
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publicvoid setCacheQueries(boolean Co/04F.
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cacheQueries){ .|:R#VW
this.cacheQueries = cacheQueries; H:q;IYE+a
} a 4?c~bs
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publicvoid setQueryCacheRegion(String |/u,6`
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queryCacheRegion){ Ih5CtcE1'd
this.queryCacheRegion = US<l4
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queryCacheRegion; !H zJ*
} ~kI$8oAry
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publicvoid save(finalObject entity){ z|<?=c2P
getHibernateTemplate().save(entity); &!>.)I`
} 8wCB}q C
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publicvoid persist(finalObject entity){ ! ^aJS'aq
getHibernateTemplate().save(entity); )|&FBz;
} @f#6Nu
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publicvoid update(finalObject entity){ =_$Hn>vO
getHibernateTemplate().update(entity); G#. q%Up
} W#L/|K!S
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publicvoid delete(finalObject entity){ Cv<
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getHibernateTemplate().delete(entity); =pb ru=/
} LKM;T-
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publicObject load(finalClass entity, .bNG:y>
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finalSerializable id){ rrs0|=
return getHibernateTemplate().load U ?6.UtNf
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(entity, id); Aot9^@4])
} GjX6noqT
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publicObject get(finalClass entity, B#o6UO\
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finalSerializable id){ }k@SmO8
return getHibernateTemplate().get ufocj1IU
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(entity, id); (~?p`g+I.P
} ;esOe\zjE
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publicList findAll(finalClass entity){ Am"&ApK
return getHibernateTemplate().find("from PeJIa
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" + entity.getName()); ,#j'~-5
} {vp*m:K
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publicList findByNamedQuery(finalString JD]uDuE
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namedQuery){ CsN^u H
return getHibernateTemplate j7J'd?l
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().findByNamedQuery(namedQuery); M[QQi2:&
} U.N?cKv
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publicList findByNamedQuery(finalString query, ur[^/lxx0
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finalObject parameter){ <4582x,G
return getHibernateTemplate zxeT{AFPr?
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().findByNamedQuery(query, parameter); ==EB\>g|
} 9A *gW j
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publicList findByNamedQuery(finalString query, dj{~!}
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finalObject[] parameters){ /|isRh|
return getHibernateTemplate 5t-,5
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().findByNamedQuery(query, parameters); q`UaJ_7
} eg24.W9c
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publicList find(finalString query){ -_XTy!I
return getHibernateTemplate().find %^[D+1ULb
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(query); A#Y:VavQ?
} K|I<kA~!H
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publicList find(finalString query, finalObject "uFwsjz&B
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parameter){ M{4XNE]m
return getHibernateTemplate().find ?$l|];m)-
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(query, parameter); n]i#&[*A(
} Sb(OG 6
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public PaginationSupport findPageByCriteria ?:G 3U\M
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(final DetachedCriteria detachedCriteria){ g/VV2^,
return findPageByCriteria <_#2+7Qs
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 'u~0rMe4})
} AQmHa2P
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public PaginationSupport findPageByCriteria qG ? :Q
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(final DetachedCriteria detachedCriteria, finalint IdK<:)Q
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startIndex){ *ifz@8C }
return findPageByCriteria }1W@
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(detachedCriteria, PaginationSupport.PAGESIZE, w
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startIndex); /(.:l +[w[
}
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public PaginationSupport findPageByCriteria ^39lUKL
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(final DetachedCriteria detachedCriteria, finalint =4l @A>
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pageSize, kguZ AO6
finalint startIndex){ :mW<
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return(PaginationSupport) b?c/J{me
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getHibernateTemplate().execute(new HibernateCallback(){ .ESvMK~x
publicObject doInHibernate -%@ah:iJ
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(Session session)throws HibernateException { ');vc~C
Criteria criteria = }ML2-k
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detachedCriteria.getExecutableCriteria(session); r9Ogez ER
int totalCount = ?-vWNv
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((Integer) criteria.setProjection(Projections.rowCount j~G(7t
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()).uniqueResult()).intValue(); 0hV#]`9`gN
criteria.setProjection {MSE}|A\V
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(null); L_RVHvA=M/
List items = 5dI=;L>D
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criteria.setFirstResult(startIndex).setMaxResults XhHgXVVGG<
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(pageSize).list(); gS5MoW1
PaginationSupport ps = d\l{tmte
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new PaginationSupport(items, totalCount, pageSize, '<BLkr# @
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startIndex); /*T^7Y&
return ps; z3K$gEve
} lAP k/G
}, true); SL- 2 ^\R
} 0Eb4wupo
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public List findAllByCriteria(final Ee2P]4_d
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DetachedCriteria detachedCriteria){ 1vj@qw3
return(List) getHibernateTemplate 8%#8PLB2
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().execute(new HibernateCallback(){ =wdh#{
publicObject doInHibernate EGUlLqP6e
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(Session session)throws HibernateException { pqb'L]
Criteria criteria = vS>'LX
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detachedCriteria.getExecutableCriteria(session); E(4c&
return criteria.list(); Hyy b0c^=
} id1cZig
}, true); C6;2Dd]"N
} w5HIR/kP
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public int getCountByCriteria(final FfJ;r'eGs
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DetachedCriteria detachedCriteria){ Bdw33z*m
Integer count = (Integer) KUUA>'=
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getHibernateTemplate().execute(new HibernateCallback(){ xR0T'@q
publicObject doInHibernate "CJ~BJI%
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(Session session)throws HibernateException { 4=([v;fc
Criteria criteria = 6e+'Y"v
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detachedCriteria.getExecutableCriteria(session); Q6qW?*Y
return f$xXR$mjf
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criteria.setProjection(Projections.rowCount \0b}Z#'0
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()).uniqueResult(); *H
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} z$%twBg}#
}, true); kcCCa@~v
return count.intValue(); :25LQf^nz
} Gaix6@X6'
} FOXSs8"c]!
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用户在web层构造查询条件detachedCriteria,和可选的 FDz`U:8
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 j]BRf A
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PaginationSupport的实例ps。 %\m"Yi]
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ps.getItems()得到已分页好的结果集 h:?^0b!@
ps.getIndexes()得到分页索引的数组 *&NP?-E
ps.getTotalCount()得到总结果数 yH/A9L,Z
ps.getStartIndex()当前分页索引 :o'x?]
ps.getNextIndex()下一页索引 &xnQLz:#
ps.getPreviousIndex()上一页索引 /|0-O''
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 %fj5;}E.
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 E/zf9\
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一下代码重构了。 M-o'`e'
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我把原本我的做法也提供出来供大家讨论吧: n>Ff tVZNJ
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首先,为了实现分页查询,我封装了一个Page类: jeC=s~
java代码: @aIgif+v
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/*Created on 2005-4-14*/ A8)4nOXM
package org.flyware.util.page; ZVjB$-do
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/** YF5}~M ymF
* @author Joa SMN.AJ
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* "aJHCi~l
*/ kaBjA*
publicclass Page { SVCh!/qe\
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/** imply if the page has previous page */ +?_!8N8
privateboolean hasPrePage; H[=\_X1o(
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/** imply if the page has next page */ 4#$#x=:
privateboolean hasNextPage; o<G 9t6~
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/** the number of every page */ =nEP:7~{
privateint everyPage; ^6s im 2
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/** the total page number */ l1 +l@r\
privateint totalPage; &K^0PzWWof
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/** the number of current page */ ai!u+L
privateint currentPage; NoI|Dz
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/** the begin index of the records by the current \nl(tU#j
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query */ >ahDc!Jyu
privateint beginIndex; n$iX6Cd
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/** The default constructor */ n
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public Page(){ fM=o?w6v
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} ,.,8-In^
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/** construct the page by everyPage 8`4M4"lj
* @param everyPage J%&LQ