Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Vea2 oQq
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Z"j #kaXA
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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 LK\L}<;1V
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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 Cw6\'p%l-\
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分页支持类: vZMb/}-o
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java代码: N~H!6N W
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package com.javaeye.common.util;
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import java.util.List; Nz/PAs7g6
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publicclass PaginationSupport { Qw>~]d,Z
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publicfinalstaticint PAGESIZE = 30; NxY B)`~
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privateint pageSize = PAGESIZE; @^P<(%p
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privateList items; 8Of.n7{
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privateint totalCount; ^UU@7cSi|G
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privateint[] indexes = newint[0]; {A^ 3<=|
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privateint startIndex = 0; 3yGo{uW
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public PaginationSupport(List items, int J9aqmQj('
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totalCount){ xB5qX7*.
setPageSize(PAGESIZE); p>#sR4d>
setTotalCount(totalCount); `qoRnG
setItems(items); F8xz^UQO
setStartIndex(0); ^mH:8_=(.
} HSwC4y}
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public PaginationSupport(List items, int -g n!8G1
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totalCount, int startIndex){ |L9p. q
setPageSize(PAGESIZE); v9k\[E?
setTotalCount(totalCount); _2Zc?*4
setItems(items); ?+)>JvWDz
setStartIndex(startIndex); p
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} :m]KVcF.
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public PaginationSupport(List items, int Ms<v81z5T
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totalCount, int pageSize, int startIndex){ C#qF&n
setPageSize(pageSize); i.Rxx, *?
setTotalCount(totalCount); pyUzHF0
setItems(items); @LSfP
setStartIndex(startIndex); B:)PUBb
} P5Bva
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publicList getItems(){ ,
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return items; 2CMWJi
} c1tM(]&
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publicvoid setItems(List items){ vzX%x ul
this.items = items; &s#O iF8
} |@W|nbAfX
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publicint getPageSize(){ .R^R32ln
return pageSize; QXI#gA
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} q}PUwN6
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publicvoid setPageSize(int pageSize){ OYyF*F&S[
this.pageSize = pageSize; C5,\DdCX,
} ,NAwSmocVP
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publicint getTotalCount(){ KzZfpdI92
return totalCount; n\GN}?4
} x)R1aq
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publicvoid setTotalCount(int totalCount){ b.q/?
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if(totalCount > 0){ fJ GwT
this.totalCount = totalCount; &>n:7
int count = totalCount / ffW-R)U|3
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pageSize; g
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if(totalCount % pageSize > 0) 8\F|{vt#
count++; i);BTwW)#]
indexes = newint[count]; uS<og P
for(int i = 0; i < count; i++){ #.<Dq8u
indexes = pageSize * -G[TlH06
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} vs^)=
}else{ g#Z7ReMw
this.totalCount = 0; =qvn?I^/
} <S^Hy&MD>
} ux8K$$$
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publicint[] getIndexes(){ 5KNa-\
return indexes; FKtG
} Z*R~dHr
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publicvoid setIndexes(int[] indexes){ sa}.o Zp Q
this.indexes = indexes; SJ}PV:x
} C).+h7{nd
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publicint getStartIndex(){ |H(i)yu"5'
return startIndex; },=ORIB B:
} N(e>]ui
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publicvoid setStartIndex(int startIndex){ ~Qd|.T
if(totalCount <= 0) au E8 ^|
this.startIndex = 0; HBNX a
elseif(startIndex >= totalCount) HXN. ,[
this.startIndex = indexes _1jbNQa
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[indexes.length - 1]; %+((F+[
elseif(startIndex < 0) 2K^xN]]rG
this.startIndex = 0; B qo#cnlG
else{ +y_V$q$G
this.startIndex = indexes usNq]
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[startIndex / pageSize]; Qe0?n
} Rzyaicj^c
} .NJ Ne
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publicint getNextIndex(){ E9 w"?_A)
int nextIndex = getStartIndex() + IrIW>r} -
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pageSize; Vp1 Q^`a{G
if(nextIndex >= totalCount) 8lyNg w1
return getStartIndex(); FzOlM-)m
else v8 II=9
return nextIndex; I* PxQ
} Uw?25+[b
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publicint getPreviousIndex(){ &p+2Vz{
int previousIndex = getStartIndex() - *'BI=*`
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pageSize; O))j
if(previousIndex < 0) xouBBb=
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else t R.>d
return previousIndex; "u'dd3!
} -M+o;
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抽象业务类 Q>xp 90&.n
java代码: /GO((v+J
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/** Gx|/
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* Created on 2005-7-12 m;sYg
*/ U ZL-mF:)&
package com.javaeye.common.business; " ;o,D
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import java.io.Serializable; ,D.@6bJW
import java.util.List; iA4VT,
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import org.hibernate.Criteria; 8SBa w'a
import org.hibernate.HibernateException; )7m.n%B!5V
import org.hibernate.Session; ]>0$l _V
import org.hibernate.criterion.DetachedCriteria; >w1jfpQ@t$
import org.hibernate.criterion.Projections; U4lAo
import <^+&A7Q-_
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org.springframework.orm.hibernate3.HibernateCallback; QvzE:]pyi
import Q@TeU#2Y
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org.springframework.orm.hibernate3.support.HibernateDaoS 2{G7ignv
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upport; 4)9Pgp:
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import com.javaeye.common.util.PaginationSupport; L(/wsw~y*
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public abstract class AbstractManager extends "^t;V+Io
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HibernateDaoSupport { ?' $}k
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privateboolean cacheQueries = false; b:&=W>r
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privateString queryCacheRegion; |vj!,b88n#
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publicvoid setCacheQueries(boolean gT|&tTS1@
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cacheQueries){ rjH W
this.cacheQueries = cacheQueries; Tt{ft?H71
} 3H5<w4yk
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publicvoid setQueryCacheRegion(String ,27=i>>
} d7o-
queryCacheRegion){ jG^OF5.
this.queryCacheRegion = ra]\!;}L0
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queryCacheRegion; ]Wc 2$
} #~6X9,x=
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publicvoid save(finalObject entity){ wHErF
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getHibernateTemplate().save(entity); z6OJT6<'
} !Mk]%
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publicvoid persist(finalObject entity){ l 4cTN
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getHibernateTemplate().save(entity); 6
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} -:V2Dsr6;
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publicvoid update(finalObject entity){ 68!=`49r>
getHibernateTemplate().update(entity); PLWx'N-kqL
} &&n-$WEl
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publicvoid delete(finalObject entity){ i^/D_L.
getHibernateTemplate().delete(entity); zQx7qx
} }}v28"\TA
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publicObject load(finalClass entity, !7uFH PK-
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finalSerializable id){ I\VC2U
return getHibernateTemplate().load ACH!Gw~
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(entity, id); RTYhgq
} E2|c;{c
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publicObject get(finalClass entity, M+\LH
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finalSerializable id){ cK2Us+h
return getHibernateTemplate().get S]DYEL$
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(entity, id); SZC1$..2T
} tP/R9Ezp
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publicList findAll(finalClass entity){ dRLvej,
return getHibernateTemplate().find("from 0bG2YMs
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" + entity.getName()); r/6h}
} u}KEH@yv
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publicList findByNamedQuery(finalString nL*
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namedQuery){ Edav }z
return getHibernateTemplate !CuLXuM
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().findByNamedQuery(namedQuery); YS&Q4nv-
} ^1+&)6s7V
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publicList findByNamedQuery(finalString query, 9@z"~H
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finalObject parameter){ .cm$*>LW:x
return getHibernateTemplate #3Jn_Y%P.
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().findByNamedQuery(query, parameter); V s1Z$HS`
} TfqQh!Y
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publicList findByNamedQuery(finalString query, eMDraJv@
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finalObject[] parameters){ {KalVZX2R
return getHibernateTemplate fwi(qx1=}
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().findByNamedQuery(query, parameters); W%cJ#R[o
} Zae$M0)
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publicList find(finalString query){ k
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return getHibernateTemplate().find E:ocx2dp
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(query); n6 a=(T
} /
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publicList find(finalString query, finalObject &\GB_UA
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parameter){ 7q[a8rUdh
return getHibernateTemplate().find '`Iuf\
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(query, parameter); 2Fsv_t&*>
} 4q\bnt
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public PaginationSupport findPageByCriteria Do5)ilt
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(final DetachedCriteria detachedCriteria){ V0x;*)\PYm
return findPageByCriteria rik0F
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); &*N;yW""f
} F"Y.'my8
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public PaginationSupport findPageByCriteria _]whHS+
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(final DetachedCriteria detachedCriteria, finalint qKg*/)sD(
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startIndex){ G>);8T%l
return findPageByCriteria nuip
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(detachedCriteria, PaginationSupport.PAGESIZE, X)peY
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startIndex); 9I;d>%
} ]hL`HP
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public PaginationSupport findPageByCriteria e$3{URg
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(final DetachedCriteria detachedCriteria, finalint Y[ciT)
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pageSize, 0qj:v"~Q
finalint startIndex){ cn$o$:tW
return(PaginationSupport) RHc-kggk!
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getHibernateTemplate().execute(new HibernateCallback(){ A+&^As2
publicObject doInHibernate kgV_*0^
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(Session session)throws HibernateException { rv\m0*\<
Criteria criteria = _Fz]QxO
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detachedCriteria.getExecutableCriteria(session); +q/ j
int totalCount = bZ$;`F5})
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((Integer) criteria.setProjection(Projections.rowCount =-e`OHA
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()).uniqueResult()).intValue(); {m)$ b
criteria.setProjection ""JTU6]MS
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(null); tJ
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List items = *?a rEYc8
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criteria.setFirstResult(startIndex).setMaxResults 69{BJ]q
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(pageSize).list(); `EUufTYi
PaginationSupport ps = #MyR:V*a
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new PaginationSupport(items, totalCount, pageSize, ?W*{%my
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startIndex); +M"Fv9
return ps; G'5p /:
} gxIGL-1M
}, true); :4f>S)m
} O"$uw
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public List findAllByCriteria(final Sd!!1as
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DetachedCriteria detachedCriteria){ PtUea
return(List) getHibernateTemplate `*J;4Ju@
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().execute(new HibernateCallback(){ 8T7E.guYr
publicObject doInHibernate wE.CZ%f
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(Session session)throws HibernateException { 3~I|KF7x
Criteria criteria = LX
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detachedCriteria.getExecutableCriteria(session); gkJL=,
return criteria.list(); QxSJLi7t
} h~]G6>D9)>
}, true); Kyz!YB
} #E?T E
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public int getCountByCriteria(final 6QwVgEnSf
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DetachedCriteria detachedCriteria){ Df\~ ZWs!
Integer count = (Integer) v-k~Q$7~
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getHibernateTemplate().execute(new HibernateCallback(){ #mI{D\UR
publicObject doInHibernate 5/vfmDt3'G
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(Session session)throws HibernateException { Rr'#OxF
Criteria criteria = b) k\?'j
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detachedCriteria.getExecutableCriteria(session); kK27hfsw
return h%9>js^~
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criteria.setProjection(Projections.rowCount >tUi ;!cQ
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()).uniqueResult(); \(ygdZ{R
} G E=J Y
}, true); $2p=vi3
return count.intValue(); otA59 ;Z
} -YXNB[C
} }e7os0;s
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用户在web层构造查询条件detachedCriteria,和可选的 DChqcdx~~
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 wLF;nzv
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PaginationSupport的实例ps。 q c(R
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ps.getItems()得到已分页好的结果集 qO;.{f
ps.getIndexes()得到分页索引的数组 aC\O'KcH
ps.getTotalCount()得到总结果数 9g7d:zG
ps.getStartIndex()当前分页索引 f<14-R=
ps.getNextIndex()下一页索引 g*]hmkYe9
ps.getPreviousIndex()上一页索引
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ''bh{
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 ?Uq;>
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一下代码重构了。 \dm5Em/
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我把原本我的做法也提供出来供大家讨论吧: s+tPHftp
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首先,为了实现分页查询,我封装了一个Page类: k? <.yr1
java代码: !lVOZ%
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/*Created on 2005-4-14*/ YFJw<5&
package org.flyware.util.page; oZD+AF$R
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/** pZ_zyI#wx_
* @author Joa F@]9oF
* )j/2Z-Ev:W
*/ :w!A_~ w2
publicclass Page { _>8rTk`/h
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/** imply if the page has previous page */ 9QQiIi$74U
privateboolean hasPrePage; Dias!$g
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