Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 "/ Gw`^t
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 7OS i2
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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 k$pND,Ws
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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 B![:fiR`
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分页支持类: zL'S5'<F|
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java代码: '`f+QP=`
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package com.javaeye.common.util; |nGv:= H@
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import java.util.List; v5U'ky:
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publicclass PaginationSupport { ze21Uj1x*
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publicfinalstaticint PAGESIZE = 30; -= izu]Fb,
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privateint pageSize = PAGESIZE; =%s6QFR
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privateList items; 1GB]Yi[>
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privateint totalCount; Q>cE G"
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privateint[] indexes = newint[0]; GSd:Plc%
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privateint startIndex = 0; AWssDbh/[
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public PaginationSupport(List items, int n$9Xj@+
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totalCount){ owb+,Gk(
setPageSize(PAGESIZE); ^7Z;=]8J
setTotalCount(totalCount); %b2Hm9r+
setItems(items); RzzU+r
setStartIndex(0); ]E'?#z.t
} !nlr!+(fV
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public PaginationSupport(List items, int c27(en(
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totalCount, int startIndex){ rS8\Vf]F
setPageSize(PAGESIZE); Upcx@zJ
setTotalCount(totalCount); dnQ6Ras
setItems(items); sg49a9`8
setStartIndex(startIndex); %r*,m3d
} 0Ub'=`]5a
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public PaginationSupport(List items, int pZ3sp!
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totalCount, int pageSize, int startIndex){ #f/4%|t:
setPageSize(pageSize); 99CK [G
setTotalCount(totalCount); sLXM$SMBh
setItems(items); b;#_?2c
setStartIndex(startIndex); $)BPtGMGo
} Q1rEUbvCE
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publicList getItems(){ $R+gA{49%
return items; #
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} _`p^B%[
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publicvoid setItems(List items){ MI(;0
this.items = items; ^S?f"''y3
} tE <?L
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publicint getPageSize(){ l&:8 'k+%=
return pageSize; iA[o;D#
} @+Sr~:K
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publicvoid setPageSize(int pageSize){ |5X59!
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this.pageSize = pageSize; xXa4t4gR
} z;Fz3s7
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publicint getTotalCount(){ SJc~E$5<
return totalCount; 9!Jt}n?!g
} dNF_T?E\
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publicvoid setTotalCount(int totalCount){
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if(totalCount > 0){ * fj`+J
this.totalCount = totalCount; uOy/c 8`
int count = totalCount / v ?}0h5
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pageSize; (E&M[hH+
if(totalCount % pageSize > 0) ZbjUOlE02
count++; ,J-|.ER->
indexes = newint[count]; 3}&3{kt
for(int i = 0; i < count; i++){ DHx&%]r;D
indexes = pageSize * $!y^t$u$@
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} (2M00J-o
}else{ /c 7z[|
this.totalCount = 0; +R HiX!PG
} \~(kGE--+
} $`ptSR
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publicint[] getIndexes(){ + G[zE
return indexes; |yzv o"3
} Il(o[Q>jJ3
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publicvoid setIndexes(int[] indexes){ CSq|R-@<U
this.indexes = indexes; ksuePMIK
} W[
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publicint getStartIndex(){ 0GeL">v,:=
return startIndex; \AA9
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} NH}o`x/
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publicvoid setStartIndex(int startIndex){ g,M-[o=Fk
if(totalCount <= 0) d;wq@e
this.startIndex = 0; js"5{w&
elseif(startIndex >= totalCount) )oz2V9X{
this.startIndex = indexes &GJVFr~z
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[indexes.length - 1]; B)1(
elseif(startIndex < 0) K[0z$T\
this.startIndex = 0; D15-pz|Q
else{ u a_w5o7
this.startIndex = indexes g\@ .qKF
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[startIndex / pageSize]; Ol+D"k~<C
} ]?wz.
} hfyU}`]
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publicint getNextIndex(){ `BG>%#
int nextIndex = getStartIndex() + %O" Whe
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pageSize; ruB D
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if(nextIndex >= totalCount) ]&q<O0^'
return getStartIndex(); \4G9YK-N>
else /V/NL#(R
return nextIndex; zNoFM/1Vb
} $qdynKK
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publicint getPreviousIndex(){ .r6x9t
int previousIndex = getStartIndex() - 1Q? RD%lkf
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pageSize; .Wy'
if(previousIndex < 0) PuGs%{$(h
return0; &Mudu/KTr
else H)gc"aRe;Y
return previousIndex; E?P>s T3B
} "G.X=,
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} n5.sx|bI?
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抽象业务类 g0U?`;n$
java代码: R2-F@_
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/** 43M.Hj]
* Created on 2005-7-12 bo\Ah/.
*/ Q*PcO \Y!y
package com.javaeye.common.business; }8aqSD<:
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import java.io.Serializable; wS#Uw_[
import java.util.List; 6fo"k+S
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import org.hibernate.Criteria; iCg%$h
import org.hibernate.HibernateException; 1v`|mU}i,
import org.hibernate.Session; E7? n'!=
import org.hibernate.criterion.DetachedCriteria; 5=|h~/.k
import org.hibernate.criterion.Projections; M80Q6K
import Z.Z;p/4F
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org.springframework.orm.hibernate3.HibernateCallback; tJ >>cFx
import `VO;\s$5j
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org.springframework.orm.hibernate3.support.HibernateDaoS Z Se30Rl\
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upport; $o5i15Oy.
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import com.javaeye.common.util.PaginationSupport; 2 A!*8w
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public abstract class AbstractManager extends Zf!Q4a"
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HibernateDaoSupport { jF}kV%E
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privateboolean cacheQueries = false; E\s1p:%
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privateString queryCacheRegion; j;_
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publicvoid setCacheQueries(boolean k@|px#kq
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cacheQueries){ L f"!:]
this.cacheQueries = cacheQueries; H2:
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} +O 7(
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publicvoid setQueryCacheRegion(String 7JQ4*RM
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queryCacheRegion){ Bx|W#:3e
this.queryCacheRegion = #9]2Uixq[
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queryCacheRegion; ^" ?a)KC
} k $gcQ:|
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publicvoid save(finalObject entity){ vJ'22)n
getHibernateTemplate().save(entity); -kLBq:M
} h092S |iY
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publicvoid persist(finalObject entity){ _yN5sLLyb
getHibernateTemplate().save(entity); $aJay]F
} t>}S@T{~T
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publicvoid update(finalObject entity){ [}HPV+j=U
getHibernateTemplate().update(entity); wQy~5+LE
} ,%IP27bPW
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publicvoid delete(finalObject entity){ iEtR<R>=
getHibernateTemplate().delete(entity); ^z)De+,!4
} v\?J=|S+
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publicObject load(finalClass entity, 7MrHu2rZ=
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finalSerializable id){ A~vx,|I
return getHibernateTemplate().load 61kSCu
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(entity, id); i&6U5Va,G
} vPYHM2
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publicObject get(finalClass entity, T>nH=
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finalSerializable id){ fG>3gS6&
return getHibernateTemplate().get *Ts$Hj[
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(entity, id); \a;xJzc9
} -avxH?;?7
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publicList findAll(finalClass entity){ Iga+8k
return getHibernateTemplate().find("from Y2l;NSWU
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" + entity.getName()); '12*'Q+{+
} =L#&`s@)_
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publicList findByNamedQuery(finalString 5Q8 H8!^
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namedQuery){ d38o*+JCf
return getHibernateTemplate [nV BnB
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().findByNamedQuery(namedQuery); [#@lsI
} qtAt=` s
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publicList findByNamedQuery(finalString query, ^rq\kf*]
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finalObject parameter){ ?C fQwY#N
return getHibernateTemplate }W 5ks-L6
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().findByNamedQuery(query, parameter); ~3gazTe9
} sHBTB6)lx
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publicList findByNamedQuery(finalString query, 6ZHeAb]"
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finalObject[] parameters){
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return getHibernateTemplate GP4!t~"1
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().findByNamedQuery(query, parameters); 4bL *7bA
} *\'t$se+
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publicList find(finalString query){ s&VsK#
return getHibernateTemplate().find 7/hn%obC
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(query); n5"oXpcIx
} v+{{j|x=
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publicList find(finalString query, finalObject $k&v
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parameter){ Ow> u!P!
return getHibernateTemplate().find K5LJx-x*j
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(query, parameter); &':C"_|&r
} 2C:u)}R7D
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public PaginationSupport findPageByCriteria Hm>cKPZ)
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(final DetachedCriteria detachedCriteria){ w]qM
return findPageByCriteria .>TG{>sH
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); :X}SuM?c
} #lqH/>`>
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public PaginationSupport findPageByCriteria uZL,%pF3A
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(final DetachedCriteria detachedCriteria, finalint dO2?&f
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startIndex){ ly34aD/p~,
return findPageByCriteria q
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(detachedCriteria, PaginationSupport.PAGESIZE, TEo
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startIndex); 9[VYd '
} ;0m J4G
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public PaginationSupport findPageByCriteria XYP
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(final DetachedCriteria detachedCriteria, finalint `.JW_F)1
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pageSize, ,sc#l<v
finalint startIndex){ xV+\R/)x
return(PaginationSupport) ?K pDEH~\
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getHibernateTemplate().execute(new HibernateCallback(){ C TG^lms
publicObject doInHibernate V2?{ebx`
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(Session session)throws HibernateException { nHbi{,3
Criteria criteria = 6P>Y2xV:
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detachedCriteria.getExecutableCriteria(session); d!T,fz/-.
int totalCount = %K3U`6kHcd
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((Integer) criteria.setProjection(Projections.rowCount 5|eX@?QF58
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()).uniqueResult()).intValue(); yw+]S
criteria.setProjection 7Z:HwZ
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(null); ->51t
List items = 1WqCezI
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criteria.setFirstResult(startIndex).setMaxResults bQI :N
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(pageSize).list(); AaB1H7r-
PaginationSupport ps = ulN1z
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new PaginationSupport(items, totalCount, pageSize, xzY/$?
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startIndex); p@Os
return ps; @Yb8CB
} l[5** ?#
}, true); <astIu Au
} Z)xcxSo
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public List findAllByCriteria(final 9:RV5Dt
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DetachedCriteria detachedCriteria){ @6DKw;Q
return(List) getHibernateTemplate 4Yok,<
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().execute(new HibernateCallback(){ -}T7F+
publicObject doInHibernate J| &aqY
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(Session session)throws HibernateException { xv$fw>
Criteria criteria = l<=k#d
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detachedCriteria.getExecutableCriteria(session); X(d:!-_m *
return criteria.list(); /o$6"~t
} xG
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}, true); !X"nN9k
} Tg@G-6u0c
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public int getCountByCriteria(final 3nhQ^zqf
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DetachedCriteria detachedCriteria){ ;6 d-+(@
Integer count = (Integer) ={o4lFe3v(
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getHibernateTemplate().execute(new HibernateCallback(){ ;dZZOocV1
publicObject doInHibernate 7mi=Xa:U
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(Session session)throws HibernateException { ?S=y>b9R
Criteria criteria = :+9. v
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detachedCriteria.getExecutableCriteria(session); EqD@o
return "S{GjOlEDF
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criteria.setProjection(Projections.rowCount nw*a?$S3
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()).uniqueResult(); ^o Ds*F
} 4$2HO`@uN
}, true); T^d<vH
return count.intValue(); K\ pZ
} ?t\GHQ$$?
} 7w5l[a/
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用户在web层构造查询条件detachedCriteria,和可选的 #>CWee;
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 1$}Tn
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PaginationSupport的实例ps。 I`@>v%0
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ps.getItems()得到已分页好的结果集 }|=Fnyj
ps.getIndexes()得到分页索引的数组 K43`$
ps.getTotalCount()得到总结果数 S9b=?? M)
ps.getStartIndex()当前分页索引 rwwyYIlEg
ps.getNextIndex()下一页索引 a&mL Dh/
ps.getPreviousIndex()上一页索引 [UdJ(cGf
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 vsA/iH.
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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 d"ZsOq10D
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一下代码重构了。 DeN2P
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我把原本我的做法也提供出来供大家讨论吧: Frx_aGLH1
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首先,为了实现分页查询,我封装了一个Page类: SZxnYVY
java代码:
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/*Created on 2005-4-14*/ qw|B-lT{:
package org.flyware.util.page; n%vmo
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/** |U~\;m@
* @author Joa &u2m6 r>W
* 0|\A5
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*/ nGJ+.z
publicclass Page { U;
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/** imply if the page has previous page */ =ZV+*cCC=q
privateboolean hasPrePage; dt=M#+g
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/** imply if the page has next page */ qssK0!-
privateboolean hasNextPage; ^|h.B$_F,
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/** the number of every page */ 4Dd]:2|D
privateint everyPage; HXB&
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/** the total page number */ T}'*Gry
privateint totalPage; d<cQYI4V
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/** the number of current page */ oBPm^ob4
privateint currentPage; >T14
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/** the begin index of the records by the current '2p,0Bk9i
*'@T+$3s
query */ ? a*yK8S
privateint beginIndex; N40DL_-
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/** The default constructor */ \gir
public Page(){ Jjx1`S*i
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} {|q(4(f"Iu
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/** construct the page by everyPage S;!7/z
* @param everyPage 6I5LZ^/ G9
* */ M"OCwBTU
public Page(int everyPage){ %wq;<'W
this.everyPage = everyPage; `4|:8@,3{
} ^
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/** The whole constructor */ S]c&