Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 0vrx5E!
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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 U~q2j#pJ
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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 ms`U,
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。 ;U]Ym48
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分页支持类: ,qT+Vqpr{
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java代码: [SU;U['7
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package com.javaeye.common.util; {B7${AE
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import java.util.List; ~+CEek
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publicclass PaginationSupport { bO+]1nZ.
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publicfinalstaticint PAGESIZE = 30; a9g~(#?a
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privateint pageSize = PAGESIZE; p&k%d, *
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privateList items; rBZ0Fx$/[
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privateint totalCount; sny$[!)
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privateint[] indexes = newint[0]; H_FT%`iM
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privateint startIndex = 0; JiFB<Q\
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public PaginationSupport(List items, int *NCkC
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totalCount){ tui5?\
setPageSize(PAGESIZE); Hd57Iw
setTotalCount(totalCount); L'u*WHj|v
setItems(items); <HH\VG\H6
setStartIndex(0); dheobD
} e5#?@}?
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public PaginationSupport(List items, int =B0AG9Fz
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totalCount, int startIndex){ 3@wio[
setPageSize(PAGESIZE); N^4CA@'{
setTotalCount(totalCount); sQBKzvFO3
setItems(items); Q PrP3DK
setStartIndex(startIndex); I+W:}}"j
} ^X ~S}MX
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public PaginationSupport(List items, int 2B b,ZC*
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totalCount, int pageSize, int startIndex){
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setPageSize(pageSize); ~Z' /b|x<3
setTotalCount(totalCount); PwU<RKAE
setItems(items); X8y :=k,E
setStartIndex(startIndex); m2[]`Ir^@
} qyzH*#d=Cf
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publicList getItems(){ ujS C
return items; sq{=TB{
} WOi+y
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publicvoid setItems(List items){ Q'rgh+6
this.items = items; lQ&J2H<w
} &Gs/#2XQ
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publicint getPageSize(){ Jw0I$W/
return pageSize; Zmm6&OZ%
} eh}|Wd7J
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publicvoid setPageSize(int pageSize){ lUd4`r"
this.pageSize = pageSize; *#83U?
} M)3'\x:
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publicint getTotalCount(){ VUC_|=?dL
return totalCount; /sr.MT
} yVWt%o/
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publicvoid setTotalCount(int totalCount){ )M*Sg?L
if(totalCount > 0){ XZT|ID_u"
this.totalCount = totalCount; 9SXpZ*Sx
int count = totalCount / 3hcWR'|
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pageSize; f`YHZ
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if(totalCount % pageSize > 0) 49=
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count++; (t5vBUj
indexes = newint[count]; EQ]>^VE2B
for(int i = 0; i < count; i++){ j\iNag(
indexes = pageSize * ySHpN>U
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i; Y>x3`f]
} a]!u
go}
}else{ .|@2Uf
this.totalCount = 0; duc\/S'
} q);oO\<
} 0{/'[o7
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publicint[] getIndexes(){ BmaY&?
return indexes; hPuF:iiQ4
} a:KL{e[
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publicvoid setIndexes(int[] indexes){ `aSbGMz
this.indexes = indexes; b^A7R{G7
} 2 SU
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publicint getStartIndex(){ ^UBzX;|p
return startIndex; ~:*V'/2k
} #vc!SI
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publicvoid setStartIndex(int startIndex){ F~/~_9RJ
if(totalCount <= 0) *;T'=u_lR
this.startIndex = 0; &5*t*tI
elseif(startIndex >= totalCount) *Ag3qnY
this.startIndex = indexes uK0L>
qp{~OW3
[indexes.length - 1]; nfh<3v|kvR
elseif(startIndex < 0) !QCErE;r
this.startIndex = 0; h6?o)Q>N
else{ pZ]&M@Ijp
this.startIndex = indexes <)
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[startIndex / pageSize]; SNf~%B?`L
} &yI>A1
} Oj8D+sC{
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publicint getNextIndex(){ jQ8
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int nextIndex = getStartIndex() + y5 X FJj
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pageSize; U+aiH U9
if(nextIndex >= totalCount) &{q<
return getStartIndex(); t"OP*
else &3SmTg
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return nextIndex; AC!yc(^<
} nI] zRduC
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publicint getPreviousIndex(){ ^S 45!mSb
int previousIndex = getStartIndex() - eN`G2eE
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pageSize; i=&]%T6Qk
if(previousIndex < 0) )1 QOA
return0; 9A87vs4[
else /S @iF
return previousIndex; R
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} di7cCn
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} 5Q: %f
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抽象业务类 %'VzN3Q5V
java代码: J&B5Ll
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/** S+*>""=
* Created on 2005-7-12 ,$U~<Zd
*/ !pHI`FeAV
package com.javaeye.common.business; "sWsK
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import java.io.Serializable; G-,0mo
import java.util.List; TD78&a#
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import org.hibernate.Criteria; F+L%Ho;@P
import org.hibernate.HibernateException; .
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import org.hibernate.Session; 3Bcv"O,B!{
import org.hibernate.criterion.DetachedCriteria; X$?0C{@.}
import org.hibernate.criterion.Projections; 4YoQ*NQw-
import AUES;2WL
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org.springframework.orm.hibernate3.HibernateCallback; 8L]Cc!~
import :B\$7+$v
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org.springframework.orm.hibernate3.support.HibernateDaoS 4~8-^^
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upport; 50a';!H
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import com.javaeye.common.util.PaginationSupport; /82E[P"}6R
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public abstract class AbstractManager extends ^ >
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HibernateDaoSupport { h"'}Z^
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privateboolean cacheQueries = false; JIqg[Mao
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privateString queryCacheRegion; y\[q2M<
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publicvoid setCacheQueries(boolean nB]mj_)R^
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cacheQueries){ `wr*@/P
this.cacheQueries = cacheQueries; J|@D @\?7
} 3o"l
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+}Mm5^6*
publicvoid setQueryCacheRegion(String *SpE
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queryCacheRegion){ ` k(Q:
this.queryCacheRegion = nc1?c1s,f
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queryCacheRegion; jVHS1Vsei
} l3/Cj^o4
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publicvoid save(finalObject entity){ P*OT&q
getHibernateTemplate().save(entity); =k;X}/
} 4vND ~9d
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publicvoid persist(finalObject entity){ MBnxF^c&P
getHibernateTemplate().save(entity); /LtbmV
} Sz]1`%_H/
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publicvoid update(finalObject entity){ }5}>B *
getHibernateTemplate().update(entity); F8M};&=*1r
} EMdU4YnE"
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publicvoid delete(finalObject entity){ %(H'
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getHibernateTemplate().delete(entity); ^NM>xIenf
} F+j"bhe
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publicObject load(finalClass entity, @;KvUR/+FE
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finalSerializable id){ 8Qj1%Ri:U
return getHibernateTemplate().load 9[DlJ@T}
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(entity, id); *)oBE{6D
} $ f||!g
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publicObject get(finalClass entity, madbl0[y.
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finalSerializable id){ {xTh!ih2-
return getHibernateTemplate().get wF59g38[z$
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(entity, id); !lA~;F
} _1WA:7$C
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publicList findAll(finalClass entity){ +ZFN8
return getHibernateTemplate().find("from M&sQnPFH
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" + entity.getName()); t**d{P+
} m9]Ge]
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publicList findByNamedQuery(finalString {Z
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namedQuery){ DJqJ6 z:'
return getHibernateTemplate zsR5"Vi=
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().findByNamedQuery(namedQuery); #&?}h)Jr'
} 4r86@^c*
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publicList findByNamedQuery(finalString query, g_?Q3
)n[=)"rf
finalObject parameter){ DbtkWq%
return getHibernateTemplate 6\.LG4@LO
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().findByNamedQuery(query, parameter); KuL+~
} 2 OqEyXh
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publicList findByNamedQuery(finalString query, @=Dc(5`[
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finalObject[] parameters){ Y##lFEt
return getHibernateTemplate rj?c
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().findByNamedQuery(query, parameters); BWB}bq
} %c%`<y<~L
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publicList find(finalString query){ 8@RJ>
return getHibernateTemplate().find LvZ',u}
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(query); WMWUP ZsGS
} fvV"H{V,
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publicList find(finalString query, finalObject #q-fRZ:P
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parameter){ /s+S\
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return getHibernateTemplate().find -"^xg"
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(query, parameter); ug;~dhe~
} {kb7u5-
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public PaginationSupport findPageByCriteria >p" U|
p _3xW{I
(final DetachedCriteria detachedCriteria){ '/AX'U8Y
return findPageByCriteria z2!4w +2
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); x3.,zfWs
} j*;.>akY7
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public PaginationSupport findPageByCriteria N[v=;&
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(final DetachedCriteria detachedCriteria, finalint H$pgzNL
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startIndex){ mZuLwd$0
return findPageByCriteria ,WM-%2z^4I
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(detachedCriteria, PaginationSupport.PAGESIZE, kg,\l9AM
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startIndex); ]1W]
} "<%J^Z9G
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public PaginationSupport findPageByCriteria wfcR[
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(final DetachedCriteria detachedCriteria, finalint {vZAOz7#
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pageSize, d\tY-X3
finalint startIndex){ FV,aQ#
return(PaginationSupport) Dca,IaT'
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getHibernateTemplate().execute(new HibernateCallback(){ %Z,n3iND
publicObject doInHibernate (A=Z,ed
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(Session session)throws HibernateException { aygK$.wos
Criteria criteria = W"CG&.
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detachedCriteria.getExecutableCriteria(session); V7O7"Q^q
int totalCount = r6:e
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((Integer) criteria.setProjection(Projections.rowCount {Ve`VV5E
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()).uniqueResult()).intValue(); In+2~Jw/2!
criteria.setProjection #^$_3AY
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(null); ?32i1F!
List items = \C$cbI=;+
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criteria.setFirstResult(startIndex).setMaxResults vL^ +X`.td
y=[{:
(pageSize).list(); h(4\k?C5
PaginationSupport ps = jpoNTl'
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new PaginationSupport(items, totalCount, pageSize, u]ps-R_$G
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startIndex); UdA,.C0
return ps; v$g\]QS
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} )@y7 qb
}, true); 02T'B&&~
} , q{~lf-
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public List findAllByCriteria(final h'_$I4e)
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DetachedCriteria detachedCriteria){ BqA_CW
return(List) getHibernateTemplate |oe
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().execute(new HibernateCallback(){ wx!2/I>
publicObject doInHibernate 9-24c
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(Session session)throws HibernateException { LX=v
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Criteria criteria = s~o\j/
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detachedCriteria.getExecutableCriteria(session); BlcsDB =ka
return criteria.list(); YIb7y1\UM
} 'm-5
}, true); c"t&,OU:
} !67xN?b
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public int getCountByCriteria(final P 6=5:-Hh
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DetachedCriteria detachedCriteria){ YRd`G3J
Integer count = (Integer) >RpMw!NT
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getHibernateTemplate().execute(new HibernateCallback(){ YNKvR
publicObject doInHibernate y|3("&)"S
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(Session session)throws HibernateException { zG^$-L.n
Criteria criteria = 4%JJ}{Ff
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detachedCriteria.getExecutableCriteria(session); &0J8ICd=
return 3v `@**
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criteria.setProjection(Projections.rowCount KDA2
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()).uniqueResult(); {/>uc,8O
} >*n4j:
}, true); EV-# E
return count.intValue(); [8oX[oP
} 'R42N3|F
} zvdIwV&oT
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用户在web层构造查询条件detachedCriteria,和可选的 ZW@cw}
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 CLJn+Y2
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PaginationSupport的实例ps。 @uG/2'B(
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ps.getItems()得到已分页好的结果集 R9QW%!:,\2
ps.getIndexes()得到分页索引的数组 d5R2J:dI
ps.getTotalCount()得到总结果数 %Q;:nVt
ps.getStartIndex()当前分页索引 ,\d03wha
ps.getNextIndex()下一页索引 F"3'~6
ps.getPreviousIndex()上一页索引 F6:LH,~8
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 T
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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 X\*H7;k,
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一下代码重构了。 K2V?[O#
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我把原本我的做法也提供出来供大家讨论吧: $~?)E;S
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首先,为了实现分页查询,我封装了一个Page类: Ay%]l| Gm
java代码: nB5^
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/*Created on 2005-4-14*/ P*hYh5a
package org.flyware.util.page; bQI.Qk
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/** (Fq]y5
* @author Joa f2v~: u
* (#>Q#Izr
*/ ,jD-fL/:
publicclass Page { .f!:@fX>=
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/** imply if the page has previous page */ j)juvat
privateboolean hasPrePage; 57;(
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/** imply if the page has next page */ u9]M3>
privateboolean hasNextPage; Mt%Q5^
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/** the number of every page */ Lw?>1rTT/
privateint everyPage; V|{~9^
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/** the total page number */ &b2@+/ F
privateint totalPage; .v9i|E=<~
?,[$8V
/** the number of current page */ gb[.Ww
privateint currentPage; \\d8ulu
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/** the begin index of the records by the current g|4>S<uC
n-<`Z NMU
query */ T ~p>Ed 9
privateint beginIndex; NvpDi&i
OGq=OW
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/** The default constructor */ FEBRUk6.h
public Page(){ tlI]);iE,
*ODc[k'(
} <UGM/+aO
ygUX ]*m!
/** construct the page by everyPage |]-~yYqP3
* @param everyPage eQqCRXx
* */ VjZb\
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public Page(int everyPage){ #ZHKq7
this.everyPage = everyPage; V_|HzYJJ5
} (+u&b< <6N
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/** The whole constructor */ Z1(!syg
public Page(boolean hasPrePage, boolean hasNextPage, Cwji,*
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int everyPage, int totalPage, \Z~
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int currentPage, int beginIndex){ l9H-N*Wx
this.hasPrePage = hasPrePage; 8*uaI7;*
this.hasNextPage = hasNextPage; !&v"+ K3lU
this.everyPage = everyPage; 9R&.$5[W(s
this.totalPage = totalPage; B\;fC's+
this.currentPage = currentPage; qa6HwlC1
this.beginIndex = beginIndex; xz7CnW1
} 8|\xU9VT
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/** !8RJHMX&
* @return =~dsIG
* Returns the beginIndex. ER4#5gd
*/ 7EL0!:P p3
publicint getBeginIndex(){ X'2%'z<
return beginIndex; ?b]f$
2
}
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/** NpA%7Q~B$,
* @param beginIndex NpGz y`&b
* The beginIndex to set. |m$]I4Jr
*/ PK_2
publicvoid setBeginIndex(int beginIndex){ Y)M-?|4
this.beginIndex = beginIndex; Ow-;WO_HQ
} wMM1Q/-#
/5\{(=0
/** P rv=f@
* @return +bWo{
* Returns the currentPage. b}hQU~,E
*/ 2D3mTpw
publicint getCurrentPage(){ Ka"1gbJ|
return currentPage; oV~S4|9:
} wFBSux$
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/** XhOg>
* @param currentPage mt-t8~A
* The currentPage to set. =]<X6!0mR
*/ .O{_^~w_q
publicvoid setCurrentPage(int currentPage){ ) LBbA
this.currentPage = currentPage; L|A1bxt
} K-@cn*6
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/** ` ^z
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* @return of`WP
* Returns the everyPage.
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*/ yv> 6u7
publicint getEveryPage(){ ]:4\rBR3
return everyPage; @ZcI]G%
} op_
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2W63/kRbU
/** Ye[Fu/0
* @param everyPage SQJ4}w>i
* The everyPage to set. #*}cc
*/ rFto1m
publicvoid setEveryPage(int everyPage){ 1.a:iweN
this.everyPage = everyPage; tA
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} :,'.b|Tl.b
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/** c{i\F D
* @return q6P5:@
* Returns the hasNextPage. D:N\K/p
*/ pEb/ yIT"
publicboolean getHasNextPage(){ T<mP.T,$!
return hasNextPage; 70nBC
} 2j[;M-3
2(Nf$?U@0
/** ;^8X(R
* @param hasNextPage ,B,0o*qc{K
* The hasNextPage to set. BR~+CBH
*/ asYUb&Hz88
publicvoid setHasNextPage(boolean hasNextPage){ _^F%$K6
this.hasNextPage = hasNextPage; =jRC4]M})
} nA+gqY6 6|
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/** p4Xhs@.k
* @return kyD*b3MN
* Returns the hasPrePage. z+Ej`$E{lD
*/ KhyGz"I!@$
publicboolean getHasPrePage(){ W!a'KI'
return hasPrePage;
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} B)&z% +
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/**
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* @param hasPrePage tSunO-\y
* The hasPrePage to set. m$$sNPnT
*/ %D+NrL(
publicvoid setHasPrePage(boolean hasPrePage){ x\5\KGw16
this.hasPrePage = hasPrePage; QV=|'
S
} <T$rvS
en16hd>^W:
/** AD"L>7
* @return Returns the totalPage. h{e?Fl
* twql)lbx
*/ qB3=wFI
publicint getTotalPage(){ @P<Mc)o^
return totalPage; ` =I@W
} .wcKG9u
FW"gj\
/** 3O?[Yhk`.
* @param totalPage 51!#m|
* The totalPage to set. <+ckE2j
*/ 5Ja[p~^L
publicvoid setTotalPage(int totalPage){ G 2FD'Sf
this.totalPage = totalPage; 2L7ogyrU/A
} -qDL':
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} k FE<M6a9@
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h.aXW]]}(P
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 bbFzmS1
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个PageUtil,负责对Page对象进行构造: 3}i(i0+
java代码: j 4eq.{$
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/*Created on 2005-4-14*/ l gTw>r
package org.flyware.util.page; n`|CDKb
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import org.apache.commons.logging.Log; WVh]<?GWXk
import org.apache.commons.logging.LogFactory; tL
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/** kC0^2./p
* @author Joa O29GPs
* G8OnNI
*/ 8>ODtKI*
publicclass PageUtil { e1 P(-V
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privatestaticfinal Log logger = LogFactory.getLog V%n7h&\%
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(PageUtil.class); .\|}5J9W
{tF)%>\#
/** e&F=w`F\
* Use the origin page to create a new page vA0f4W 8+
* @param page Cq<k(TKAX
* @param totalRecords S(hT3MAW
* @return O|0} m
*/ Xa&0j&AH
publicstatic Page createPage(Page page, int 604^~6
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totalRecords){ Cg%}=
return createPage(page.getEveryPage(), w:@W/e*9N
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page.getCurrentPage(), totalRecords); UJrN+RtL
} `:EU~4s\
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/** (Z at|R.F
* the basic page utils not including exception ;%$wA5"2M
G'6f6i|<I@
handler ^1z)\p1
* @param everyPage =-n7/
* @param currentPage 8POLp9>X
* @param totalRecords ,\0>d}eh!
* @return page F;)qM|7
*/ p (x<h
publicstatic Page createPage(int everyPage, int 3Cl&1K #5
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currentPage, int totalRecords){ ,M$J
yda
everyPage = getEveryPage(everyPage); K7]IAV
currentPage = getCurrentPage(currentPage); 2B=+p83<
int beginIndex = getBeginIndex(everyPage, ,:?=j80m
jI,?*n<
currentPage); %1%@L7wP>
int totalPage = getTotalPage(everyPage, ]j^rJ|WTH
OJPi*i 5*
totalRecords); c:_dW;MJ0
boolean hasNextPage = hasNextPage(currentPage, S+//g+e|f
#l-/!j
totalPage); ? ]hS^&
boolean hasPrePage = hasPrePage(currentPage); (/3E,6gMk^
6yXMre)YV
returnnew Page(hasPrePage, hasNextPage, Mg=R**s1x%
everyPage, totalPage, f&`yiy_
currentPage, kDK0L3}nr]
$C9['GGR
beginIndex); wlfq$h p
} (t2vt[A6ph
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privatestaticint getEveryPage(int everyPage){ 6B`,^8Lp
return everyPage == 0 ? 10 : everyPage; A,! YXl[
} bDM;7fFp$
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privatestaticint getCurrentPage(int currentPage){ 5D`!Tu3
return currentPage == 0 ? 1 : currentPage; R(<_p"9(
} 6gJc?+
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privatestaticint getBeginIndex(int everyPage, int rJ fO/WK
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currentPage){ Qe1WT T]:I
return(currentPage - 1) * everyPage; s f<NC>-
} ueV,p?Wo
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privatestaticint getTotalPage(int everyPage, int cg'z:_l
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totalRecords){ #]FJx
int totalPage = 0; OK=ANQjs(
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if(totalRecords % everyPage == 0) EF[I@voc
totalPage = totalRecords / everyPage; (pkq{: Fs
else t
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totalPage = totalRecords / everyPage + 1 ; G;v3kGn
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return totalPage; H(F9&6}
} &=hkB9
;
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privatestaticboolean hasPrePage(int currentPage){ n%={!WD
return currentPage == 1 ? false : true; [,|;rt\o>
} `& }C*i"
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privatestaticboolean hasNextPage(int currentPage, ^<QF*!
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int totalPage){ geEETb}+y
return currentPage == totalPage || totalPage == yDXW#q
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0 ? false : true; Lo^gg#o
} <%EjrjdvL+
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} I=}pT50~9
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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。 wBIhpiJX0
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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 -<M'h
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做法如下: V( SRw
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 SH#!Y
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的信息,和一个结果集List: vC ISd
java代码: *d$r`.9j
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/*Created on 2005-6-13*/ dn|OY.`|
package com.adt.bo; NGOyd1$7N
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import java.util.List; 2kVQ#JyuRI
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import org.flyware.util.page.Page; f`"@7-N
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/** 8$y5) ~Q
* @author Joa i $;y
*/ +a}>cAj*
publicclass Result { c$52b4=a
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private Page page; FG6mh,C!
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private List content; #x[3@zP.
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/** w@&(=C
* The default constructor AG(Gtvw
*/ i+eDBg6
public Result(){ 4'BZ +A,p
super(); pQ yH`
} R1NwtnS
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/** &1$|KbmV4
* The constructor using fields a7wc>@9Q,
* { K*
* @param page 9>hK4&m^
* @param content ?N(opggiD
*/ m. "T3K
public Result(Page page, List content){ El4SL'E@
this.page = page; BhC>G2 ^7
this.content = content; P1A5Qq
} C!s !j
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/** U.p"JSH
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* @return Returns the content. wA?q/cw C
*/ N/i {j.=
publicList getContent(){ <^Sp4J
return content; wzz>N@|
} KB6`OT^b{r
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/** 2!;U.+(
* @return Returns the page. Ki(
*/ (YKkJ
public Page getPage(){ '
return page; WDq~mi
} QTT2P(Pz
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/** G+zIh}9
* @param content FCA]zR1
* The content to set. 2}jC%jR2
*/ xI(Y}>
public void setContent(List content){ p~NFiZ,
this.content = content; S^*ME*DDz
} 3KN>t)A#
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/** 8KyF0r?
* @param page 5;_&C=[
* The page to set. !R@s+5P)U
*/ 2JX@#vQ4
publicvoid setPage(Page page){ D~LU3#n
this.page = page; KG9FR*"
} QDpzIjJj
} K6M_b?XekA
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2. 编写业务逻辑接口,并实现它(UserManager, d
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UserManagerImpl) &