Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 @4MQ021(
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 HA7%8R*.2i
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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 Ke=+D'=
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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 luyu7`
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分页支持类: fFYoZ/\
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java代码: Dv
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package com.javaeye.common.util; ,I ][
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import java.util.List; 4Gh\T`=
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publicclass PaginationSupport { bo(w$&
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bar=^V)
publicfinalstaticint PAGESIZE = 30; }S3 oX$
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privateint pageSize = PAGESIZE; pPag@L
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privateList items; .Gvk5Wn
psc
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privateint totalCount; Dte5g),R
{
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privateint[] indexes = newint[0]; awvP;F?q|
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privateint startIndex = 0; s;=C&N5g
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public PaginationSupport(List items, int R dwt4A+
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totalCount){ h3&|yS|
setPageSize(PAGESIZE); ;gSRpTS:
setTotalCount(totalCount); xy4+
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setItems(items); w=n(2M56C
setStartIndex(0); B>m*!n:l
} %>_6&A{K,d
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public PaginationSupport(List items, int MpGG}J[y
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totalCount, int startIndex){ \q4r/SbgW
setPageSize(PAGESIZE); .|5$yGEF_+
setTotalCount(totalCount); Mqvo
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setItems(items); jl&Nphp
setStartIndex(startIndex); e0(aRN{W
} #vxq|$e
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public PaginationSupport(List items, int Qni`k)4
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totalCount, int pageSize, int startIndex){ !|i #g$
setPageSize(pageSize); dt,Z^z+"E
setTotalCount(totalCount); YzQ1c~+
setItems(items); D9A%8[Yo
setStartIndex(startIndex); eh `%E0b}
} DyiJ4m}kh
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publicList getItems(){ C !Srv7
return items; <Nqbp
} gCC7L(1
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publicvoid setItems(List items){ 0
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this.items = items; 3]*1%=~X/
} #Gg^QJ*
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publicint getPageSize(){ lV%1I@[M
return pageSize; B 5|\<CF
} ;%^=V#
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publicvoid setPageSize(int pageSize){ E'DHO2
Y
this.pageSize = pageSize; ]lBCK
} (BeJ,K7
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publicint getTotalCount(){ -dBWpT
return totalCount; XDPgl=~
} +jwHYfAK)
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publicvoid setTotalCount(int totalCount){ tOLcnWt
if(totalCount > 0){ !Vw1w1
this.totalCount = totalCount; A8Q^y
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int count = totalCount / M\5|
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pageSize; !h7.xl OpN
if(totalCount % pageSize > 0) @e
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count++; Gb\PubJ
indexes = newint[count]; 0~^RHb.NA8
for(int i = 0; i < count; i++){ /~ {`!30
indexes = pageSize * E6 -*2U)k+
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i; </`\3t
} >- \bLr
}else{ :1>?:3,`
this.totalCount = 0; q_h (D/g
} `z0q:ME
} uwSSrT
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publicint[] getIndexes(){ }r5yAE
return indexes; 7}UG&t{
} PVBz~rG
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publicvoid setIndexes(int[] indexes){ d/&>
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this.indexes = indexes; g=56|G7n
} Tz,9>uN
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publicint getStartIndex(){ njaMI8|Pa
return startIndex; *kl :/#
} ~(QfVpRnV=
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publicvoid setStartIndex(int startIndex){ vyIH<@@p7
if(totalCount <= 0) ,
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this.startIndex = 0; SXm%X(JU
elseif(startIndex >= totalCount) WQ.0} n}d
this.startIndex = indexes *{DTxEy
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[indexes.length - 1]; d}[cX9U/
elseif(startIndex < 0) c0gVW~I1
this.startIndex = 0; Dp
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else{ `x`[hJ?i
this.startIndex = indexes l[38cF
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[startIndex / pageSize]; l?U=s7s0?
} 3S:Lce'f
} l4oyF|oJTH
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publicint getNextIndex(){ 27e!KG[&
int nextIndex = getStartIndex() + Hsf::K x
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pageSize; 8Y?M:^f~
if(nextIndex >= totalCount) L=4+rshl!_
return getStartIndex(); v3I^81
else X g6ezlW
return nextIndex; EO&Q
} vjuFVJwL
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publicint getPreviousIndex(){ F)LbH&Kn
int previousIndex = getStartIndex() - WTJ 0Q0U
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pageSize; bO=|utpk
if(previousIndex < 0) ;.A}c)b
return0; ]%' AZ`8
else u5(8k_7
return previousIndex; 0ns\:2)cEB
} +WH\,E
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} FlBhCZ|^
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抽象业务类 9zu;OK%
java代码: 1@F-t94I
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/** @rTB&>`
* Created on 2005-7-12 3e_tT8
*/ 52w@.]
package com.javaeye.common.business; y6XOq>
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import java.io.Serializable; p)y5[HX
import java.util.List; .uuhoqG0
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import org.hibernate.Criteria; /eF@a!
import org.hibernate.HibernateException; <^5!]8*O
import org.hibernate.Session; UVo`jb|>
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import org.hibernate.criterion.DetachedCriteria; ^#9385
import org.hibernate.criterion.Projections;
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import +V3mF_s|z
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org.springframework.orm.hibernate3.HibernateCallback; {213/@,
import p5G'})x
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org.springframework.orm.hibernate3.support.HibernateDaoS 8dGsV5" *
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upport; 9LDv?kYr
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import com.javaeye.common.util.PaginationSupport; m{\
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public abstract class AbstractManager extends |7qt/z
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HibernateDaoSupport { z$~x 2<
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privateboolean cacheQueries = false; '!HTE`Aj
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privateString queryCacheRegion; L5&M@YTH
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publicvoid setCacheQueries(boolean L)e"qC_-
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cacheQueries){ YvR bM
this.cacheQueries = cacheQueries; J=g)rd[`
} ]PXM;w
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publicvoid setQueryCacheRegion(String A_xC@$1e<
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queryCacheRegion){ {{G)Ry*pb
this.queryCacheRegion = +7_qg
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queryCacheRegion; CIudtY(:
} :U6`n
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publicvoid save(finalObject entity){ PL/g| ;
getHibernateTemplate().save(entity); p~D}Iyww1_
} k<gH*=uXY'
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publicvoid persist(finalObject entity){ BU`X_Z1)
getHibernateTemplate().save(entity); ':*H#}Br-#
} \J'}CX*aQ
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publicvoid update(finalObject entity){ 7^L
getHibernateTemplate().update(entity); $:9t(X)H
} }EK{UM9y
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publicvoid delete(finalObject entity){ KC/O
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getHibernateTemplate().delete(entity); x#1Fi$.
} PR:k--)D
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publicObject load(finalClass entity,
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finalSerializable id){ -3K h
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return getHibernateTemplate().load I)HO/i6>3
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(entity, id); 01cBAu
} i|:!I)(lh
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publicObject get(finalClass entity, C}huU
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finalSerializable id){ 6VW*8~~Xy
return getHibernateTemplate().get ;ALWL~Xm
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(entity, id); f"6W ;b2L.
} HuhQ|~C+~
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publicList findAll(finalClass entity){ gV_v5sk
return getHibernateTemplate().find("from SNj-h>&Mha
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" + entity.getName()); : |'(T[~L
} (7 I|lf
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publicList findByNamedQuery(finalString ?sN{U\
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namedQuery){ X[B P0:`t
return getHibernateTemplate YT(N][V
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().findByNamedQuery(namedQuery); ]#:WL)@
} O8]e(i
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publicList findByNamedQuery(finalString query, :i.@d?
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finalObject parameter){ (< +A w7
return getHibernateTemplate j=r1JV
@
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().findByNamedQuery(query, parameter); omE- c
} ! M^O\C)
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publicList findByNamedQuery(finalString query, !"^Zr]Qt+\
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finalObject[] parameters){ D<WnPLA$g
return getHibernateTemplate v,w af`)J
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().findByNamedQuery(query, parameters); m8sd2&4
} ] Q5:JV
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publicList find(finalString query){ Ht[$s4 0P
return getHibernateTemplate().find {4J.
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(query); ]Lv3XMa
} |ADf~-AY
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publicList find(finalString query, finalObject ?eS;Yc
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parameter){ <>HtXn/
return getHibernateTemplate().find L}h_\1
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(query, parameter); s"jvO>[
} ~F"S]
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public PaginationSupport findPageByCriteria 'z|Da &d P
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(final DetachedCriteria detachedCriteria){ C19N0=
return findPageByCriteria #W~jQ5NS\
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); Ark]>4x>
} ~1O|4mssS
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public PaginationSupport findPageByCriteria DzVCEhf
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(final DetachedCriteria detachedCriteria, finalint !v8R(
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startIndex){ tVG;A&\,6
return findPageByCriteria 7O55mc>cF
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(detachedCriteria, PaginationSupport.PAGESIZE, 5]&sXs
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startIndex); _r:Fmn_%-
} Im6gWDdq@6
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public PaginationSupport findPageByCriteria <|r|s
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(final DetachedCriteria detachedCriteria, finalint 2;gvo*k
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pageSize, Y_CYx
finalint startIndex){ ]Thke 4
return(PaginationSupport) Va )W[I
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getHibernateTemplate().execute(new HibernateCallback(){ F0!Z1S0g
publicObject doInHibernate I8XP`Ccq
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(Session session)throws HibernateException { ,zgz7
Criteria criteria = s4fO4.bn m
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detachedCriteria.getExecutableCriteria(session); S%- kN;
int totalCount = T\9[PX<
N**)8(
((Integer) criteria.setProjection(Projections.rowCount /B t!xSI
u\ _yjv#
()).uniqueResult()).intValue(); CHGa_
criteria.setProjection k9%o{Uzy
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(null); x'g4DYl
List items = lJ;Wi
'LMj.#A<g
criteria.setFirstResult(startIndex).setMaxResults y'm!h?8
Y# }qXXZ>]
(pageSize).list(); [gT}<W
PaginationSupport ps = [mzed{p]]
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new PaginationSupport(items, totalCount, pageSize, y"yo\IDW
qb[hKp5K6
startIndex); -6+7&.A+
return ps; 3RaW\cWzg
} +(2$YJ35
}, true); :(]fC~G~
} _tHhS@
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public List findAllByCriteria(final 0!,uo\`
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DetachedCriteria detachedCriteria){ %M`48TW)
return(List) getHibernateTemplate Fq~uuQ
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().execute(new HibernateCallback(){ l_}d Q&R
publicObject doInHibernate b*Y Wd3
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(Session session)throws HibernateException { O q$_ q
Criteria criteria = Wh i#Ii~
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detachedCriteria.getExecutableCriteria(session); `rVru= zoy
return criteria.list(); yMWh#[phH
} zjA]Tr
}, true); YH\9Je%jx
} aqEZhMy
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public int getCountByCriteria(final +vy fhw4
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DetachedCriteria detachedCriteria){ ['o ueOg
Integer count = (Integer) Kkp dcc
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getHibernateTemplate().execute(new HibernateCallback(){ 'yPKQ/y$x
publicObject doInHibernate ES4Wtc)&
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(Session session)throws HibernateException { <kFLwF?PM'
Criteria criteria = _;03R{e*
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detachedCriteria.getExecutableCriteria(session); k^Qf |
return %]Z4b;W[Y
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criteria.setProjection(Projections.rowCount qA GjR!=^
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()).uniqueResult(); l$/pp
} aB6xRn9
}, true); ]i#p2?BR
return count.intValue(); B`mJT*B[
} @F5Af/
} 83c2y;|8
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用户在web层构造查询条件detachedCriteria,和可选的 (j'\h/
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 AI2XNSV@Yl
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PaginationSupport的实例ps。 FPY k`D
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ps.getItems()得到已分页好的结果集 4Et(3[P71
ps.getIndexes()得到分页索引的数组 x{:U$[_
ps.getTotalCount()得到总结果数 |H
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ps.getStartIndex()当前分页索引 9InP2u\&:
ps.getNextIndex()下一页索引 fc+-/!v
ps.getPreviousIndex()上一页索引 ^^V3nT2rR3
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 U"7o;q
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 T!H(Y4A
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一下代码重构了。 1)=
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我把原本我的做法也提供出来供大家讨论吧: 5$=[x!x
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首先,为了实现分页查询,我封装了一个Page类: QDn_`c
java代码: E,m|E]WP
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/*Created on 2005-4-14*/ "zq'nV=
package org.flyware.util.page; MUl`0H"tR
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/** PaSwfjOnqr
* @author Joa d7kE}{,
* oSrA4g
*/ 'aEK{#en
publicclass Page { wK2$hsque
c= t4 gf
/** imply if the page has previous page */ iOZ9A~Ywy
privateboolean hasPrePage; Tg^8a,Lt
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/** imply if the page has next page */ ]izHn; +
privateboolean hasNextPage; 1T#-1n%[k(
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/** the number of every page */ gqv+|:#
privateint everyPage; $?F_Qsy{d
;[ QIHA!
/** the total page number */ ,C6(
privateint totalPage; GgEg (AT
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/** the number of current page */ C1{Q 4(K%
privateint currentPage; FZgf"XM>
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/** the begin index of the records by the current `pfgx^qG
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query */ y"H5>
privateint beginIndex; q2xAx1R`sV
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/** The default constructor */ _8$xsj4_
public Page(){ r4u,I<ZbH
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} Wg %]
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/** construct the page by everyPage <!t;[ie?y
* @param everyPage ;LgMi5dN
* */ c*#$sZ@YA
public Page(int everyPage){ I 8i|tQz
this.everyPage = everyPage; \0lQ1FrY
} CHS}tCfos>
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/** The whole constructor */ KOR*y(* 8
public Page(boolean hasPrePage, boolean hasNextPage, T=w0T-[f
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nEUH; z
int everyPage, int totalPage, ,^CG\);
int currentPage, int beginIndex){ [GCaRk>b,
this.hasPrePage = hasPrePage; UK'8cz9
this.hasNextPage = hasNextPage; X%I@4 B7Ts
this.everyPage = everyPage; qCVb-f
this.totalPage = totalPage; .HTRvE`X
this.currentPage = currentPage; y z3=#
this.beginIndex = beginIndex; 0{d)f1
} pbh>RS=ri
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/** ~Q^.7.-T
* @return V,Bol(wY
* Returns the beginIndex. k0FAI0~(
*/ nCV7(ldmH
publicint getBeginIndex(){ b$Ei>%'/";
return beginIndex; @(6P L^I
} 2I suBX\[
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/** q( EN]W],
* @param beginIndex (3K,f4S@
* The beginIndex to set. \u6.*w5TI
*/ ;fQIaE&H
publicvoid setBeginIndex(int beginIndex){ %Ze7d&
this.beginIndex = beginIndex; 6[FXgCb
} nql{k/6
Y ajAz5N
/** o]]tH
* @return ijcF[bmE
* Returns the currentPage. &D|+tu{
*/ -oZw+ge}
publicint getCurrentPage(){ B}zBbB
return currentPage; iu0'[
} Dg Rn^gL{Q
]2&RN@
/** Nw,|4S
* @param currentPage 0}`
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* The currentPage to set. ^\S~rW.3_
*/ mWP&N#vwh
publicvoid setCurrentPage(int currentPage){ Y#P!<Q>}
this.currentPage = currentPage; Q"!GdKM
} ES(qu]CjI
zDm3$P=
/** 1JOoICjB
* @return aU.!+e%_
* Returns the everyPage. H:Q4!<
*/ k:mW ,s|a
publicint getEveryPage(){ Aj/EaIq
return everyPage; `Um-Y'KE
} }0/l48G
.Y!dO@$:
/** "fN
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* @param everyPage ym` 4v5w
* The everyPage to set. H4wDF:n0H
*/ S s+
publicvoid setEveryPage(int everyPage){ FLG{1dS
this.everyPage = everyPage; J_<6;#
} O"X7 DgbC
"ChJR[4@
/** 3:c6x kaw
* @return {XC[Ia6jtL
* Returns the hasNextPage. R%9,.g<
*/ " w /Odd
publicboolean getHasNextPage(){ LOwd mj
return hasNextPage; 1bDXv,nD
} &:}WfY!hX
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/** |v#rSVx
* @param hasNextPage Da)_O JYE
* The hasNextPage to set. [CAFh:o
*/ EAC I>
publicvoid setHasNextPage(boolean hasNextPage){ B<G,{k
this.hasNextPage = hasNextPage; aM_O0Rn==
} j(>xP*il
.rX,*|1x
/** .jbxA2
* @return IF6-VFY:6
* Returns the hasPrePage. ZC^NhgX
*/ ]$-<< N{}'
publicboolean getHasPrePage(){ CZ{7?:^f
return hasPrePage; &2ty++gC
} )tS;gn
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/** /*M3Ns1@2
* @param hasPrePage r'o378]=
* The hasPrePage to set. 5e?<x>e
*/ R.
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publicvoid setHasPrePage(boolean hasPrePage){ LEX @hkh
this.hasPrePage = hasPrePage; {/,AMJ<:G]
} VZ
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B;piO-hH
/** {r5OtYmpR
* @return Returns the totalPage. {&6i$4T
* G9GLRdP
*/ DhsvN&yNM
publicint getTotalPage(){ O*W<za;
return totalPage; |TR
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} ip1gCH/?_+
>Ml5QO$*.q
/** 2Je]dj4
* @param totalPage ?|\wJrM ]
* The totalPage to set. #ZP;] W
*/ Jz P0D'
publicvoid setTotalPage(int totalPage){ [Q/kNK
this.totalPage = totalPage; } .<(L
} {lgiH+:
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} +F2X2e)g"
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4:/^ .:
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 l/\D0\x2
XGjFb4Tw7
个PageUtil,负责对Page对象进行构造: VYt<j<ba
java代码: 1-&L-c.
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/*Created on 2005-4-14*/ A
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package org.flyware.util.page; g#cet{>
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import org.apache.commons.logging.Log; =2ED
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import org.apache.commons.logging.LogFactory; TU*EtE'g/
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/** KC9e{
* @author Joa bMNr +N
* ZmNNR 1%/
*/ l=((>^i
publicclass PageUtil { M]/DKo
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privatestaticfinal Log logger = LogFactory.getLog lBAu@M
c"pOi&
(PageUtil.class); ]^>:)q
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/** ffBd
* Use the origin page to create a new page N;6o=^ic
* @param page M}f(-,9
* @param totalRecords t8rFn
* @return HEIg_6sb
*/ o0|Ex\
publicstatic Page createPage(Page page, int I~@8SSO,vH
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totalRecords){ b78~{ht`
return createPage(page.getEveryPage(), evYn}
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page.getCurrentPage(), totalRecords); k+w Ji
} o[iN/
1 <+aF,
/** hqmE]hwc
* the basic page utils not including exception _vDmiIn6K
"42/P4:
handler :zPK
* @param everyPage }u=Oi@~
* @param currentPage ;l
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* @param totalRecords wWiYxBeN
* @return page MGt>:&s(]
*/ QuPz'Ut#
publicstatic Page createPage(int everyPage, int Qz#By V:
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currentPage, int totalRecords){ vZ"gCf3#?3
everyPage = getEveryPage(everyPage); UU MB"3e
currentPage = getCurrentPage(currentPage); \y]K]iv
int beginIndex = getBeginIndex(everyPage, =\5WYC
,f$P[c
currentPage); KvPCb%!ZP
int totalPage = getTotalPage(everyPage, 3Z=yCec]
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totalRecords); /pPH D]
boolean hasNextPage = hasNextPage(currentPage,
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-bzlp7q*
totalPage); a*U[;(
boolean hasPrePage = hasPrePage(currentPage); cK u[4D{
ng!cK<p
returnnew Page(hasPrePage, hasNextPage, #]tDxZ]
6
everyPage, totalPage, 3zD#V3=
currentPage, wGKxT
ap
": M]3.
beginIndex); vf{$2rC
} n-cI~Ax+4
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privatestaticint getEveryPage(int everyPage){ d\]KG(T
return everyPage == 0 ? 10 : everyPage; QhJN/v
} J'X}6Q
'kt6%d2
privatestaticint getCurrentPage(int currentPage){ 'WP~-}(
return currentPage == 0 ? 1 : currentPage; aO&{.DO2
} S*h^7?Bu
s0f+AS|}
privatestaticint getBeginIndex(int everyPage, int
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currentPage){ *pa hZiO
return(currentPage - 1) * everyPage; ?96r7C|
} E2>{se Z
{] ]%0!n\
privatestaticint getTotalPage(int everyPage, int Yu_*P-Ja6
v9:J 55x
totalRecords){ 5.{=Op!
int totalPage = 0; KJec/qca
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if(totalRecords % everyPage == 0) l%"DeRp,/
totalPage = totalRecords / everyPage; O|8@cO
else 6GunEYK!N8
totalPage = totalRecords / everyPage + 1 ; Eb4NPWo
t"GnmeH
i
return totalPage; {L7Pha
} M^:JhX{
u'l4=e
privatestaticboolean hasPrePage(int currentPage){ XYWyxx5`
return currentPage == 1 ? false : true; >2{Y5__+e
} + m-88
&!X<F,
privatestaticboolean hasNextPage(int currentPage, U?Jk
g@>llve{
int totalPage){ #17 &rizl
return currentPage == totalPage || totalPage == <?7qI8 5OT
g,JfT^
0 ? false : true; 2.%)OC!q&5
} y7F
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} qG;tD>jy
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 <7U~0@<Y
59)w+AW
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 VNWB$mM.2
d|RUxNjM-J
做法如下: L3Y,z3/
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 <)T| HKx
V>QyiB
的信息,和一个结果集List: akyMW7'3V<
java代码: /lC# !$9vz
h s',f
>IaGa!4
/*Created on 2005-6-13*/ AA=Ob$2$
package com.adt.bo; aNu.4c/5
*`+zf7-f
import java.util.List; cQt&%SVT]E
F@Sk=l(
import org.flyware.util.page.Page; j<(E%KN3
phu,&DS!
/** Jd7chIK
* @author Joa A^z{n/DiL
*/ 3*</vo#`
publicclass Result { bfA>kn0C
b+qd'
,.Z
private Page page; 9 o,`peH
htbE
Q NW
private List content; ,7@\e&/&
p48enH8CO
/** D{JjSky
* The default constructor P0}B&B/a:
*/ .@)vJtH)
public Result(){ 6Pl|FIJF
super(); w|&lRo@1
} D-{*3?x
sA?8i:]O:
/** "e"#k}z9
* The constructor using fields ^ELZ35=qZ
* <?B3^z$
* @param page 8
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* @param content F62 uDyY
*/ k( 0; >)<i
public Result(Page page, List content){ }MOXJb @
this.page = page; >G|RVB
this.content = content; kZG=C6a
} jm%s#`)g
SWzqCF
/** 9
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* @return Returns the content. CqEbQ>?
*/ EmT_T3v
publicList getContent(){ D'!JV1Q
return content; X:s~w#>R
} Ee}|!n>
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/** mQ`atFz:Z
* @return Returns the page. S'HA]
*/ .9x*YS
public Page getPage(){ %WU=Vy 4
return page; WS[Z[O
} L~PiDQr?r
YT8q0BR]
/** `0ym3} (O
* @param content 5!A:xV]6]
* The content to set. Zo2+{a
*/ ;MGm,F,o
public void setContent(List content){ 2 %fcDEG/
this.content = content; ,Gv}N&
} 1P"7.{
M <JX
/** $H+X'1
* @param page I<RARB-j
* The page to set. :"#
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*/ xKE=$SV(
publicvoid setPage(Page page){ fSd|6iFH
this.page = page; VB90 5%
} r rfJs
} .t[u_tBL
e~
OrZhJ=_
fUf1G{4
95IP_1}?
1p~ORQ
2. 编写业务逻辑接口,并实现它(UserManager, {wM<i
{f/]K GGk
UserManagerImpl) Mhn1-ma:
java代码: l4T[x|')M
Q^va+O
Ju#j%!
/*Created on 2005-7-15*/ ZFMO;'m&
package com.adt.service; "gNi}dB<]
e~gNGr]L/
import net.sf.hibernate.HibernateException; 'eBD/w5U
>k\p%{P
import org.flyware.util.page.Page; T\Xf0|y
~6t<`&f
import com.adt.bo.Result; Qa/1*Mb
KsIHJr7-
/** 8Ckd.HKpQ
* @author Joa 6I(Y<LZ5
*/ 7R[7M%H
publicinterface UserManager { &b