Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 n]>L"D,
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 7ZUS
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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 LKZv#b[h
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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 Owv}lJ
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分页支持类: ll?Qg%V[t
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java代码: PO|gM8E1x?
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package com.javaeye.common.util; 0W~1v
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import java.util.List; xhB-gG=
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publicclass PaginationSupport { /03?(n= 3
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publicfinalstaticint PAGESIZE = 30; {s=c!08=
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privateint pageSize = PAGESIZE; DU-dIqi
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privateList items; (?i4P5s[!
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privateint totalCount; K
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privateint[] indexes = newint[0]; KHM,lj*
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privateint startIndex = 0; q#"lnc<S
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public PaginationSupport(List items, int $^YHyfh
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totalCount){
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setPageSize(PAGESIZE); n8FIxl&u
setTotalCount(totalCount); j{/5i`5m
setItems(items); V}FH5z
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setStartIndex(0); 4{0vdpo3F
} <)"2rxX&5
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public PaginationSupport(List items, int n-1
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totalCount, int startIndex){ anORoK.
setPageSize(PAGESIZE); u]]mbER*t#
setTotalCount(totalCount); u_b6u@r7
setItems(items); 4~hP25q
setStartIndex(startIndex); ={jj'X9
} 5D mSgP:
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public PaginationSupport(List items, int M7YbRl
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totalCount, int pageSize, int startIndex){ *=Ma5J.
setPageSize(pageSize); |`+ (O
setTotalCount(totalCount); MFipXE!
setItems(items); H)Z$j&S{
setStartIndex(startIndex); f{|n/j;n=C
} 'vKae
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publicList getItems(){ PeSTUR&
return items; Vw`%|x"Xz
} gRZ!=z[&
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publicvoid setItems(List items){ Rk{vz|
this.items = items; nk;+L
} j|b$b,rF\
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publicint getPageSize(){ fe}RmnAC
return pageSize; :]LW,Eql
} C\0,D9
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publicvoid setPageSize(int pageSize){ fr8';Jm
this.pageSize = pageSize; @[Wf!8_
} cVSns\QO
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publicint getTotalCount(){ hK3Twzte
return totalCount;
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} zv^+8h7k
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publicvoid setTotalCount(int totalCount){ |{rhks~
if(totalCount > 0){ 9MbF:
this.totalCount = totalCount; 4% 6@MQ[
int count = totalCount / 0;w84>M
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pageSize; U?Vik
if(totalCount % pageSize > 0) -tp3qi
count++; T7 (d
indexes = newint[count]; "i!W(}x+
for(int i = 0; i < count; i++){ C\ 34R
indexes = pageSize * 6HH:K0j3'
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i; %iZ~RTY6 !
} qr~zTBT]
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}else{ *~.'lE%[U
this.totalCount = 0; ~x J#NC+
} CU/Id`"tW
} 1`Uu;mz
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publicint[] getIndexes(){ Ol;"}3*Z*
return indexes; X& XD2o"rt
} "DRiJ.|APs
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publicvoid setIndexes(int[] indexes){ #=Whh
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this.indexes = indexes; =n;LP#(h ?
} $4]4G=o
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publicint getStartIndex(){ H<qz
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return startIndex; tNAmA
} >B.KI}dE
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publicvoid setStartIndex(int startIndex){ nr&9\lG]G
if(totalCount <= 0) &7eN
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this.startIndex = 0; 6?/f$,v
elseif(startIndex >= totalCount) =$_kkVQ$
this.startIndex = indexes p;mV?B?oAQ
^Jc|d,u;s
[indexes.length - 1]; 1=^|
elseif(startIndex < 0) ayN[y
this.startIndex = 0; %)e&"mq!|
else{ O`;o"\P<
this.startIndex = indexes Z[kVVE9b?
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[startIndex / pageSize]; | }d+BD
} MQX9BJ%
} ~6[3Km|2
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publicint getNextIndex(){ ]oKHS$W9
int nextIndex = getStartIndex() + ];u nR<H
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pageSize; Zb+n\sv4
if(nextIndex >= totalCount) - P4X@s_;
return getStartIndex(); ;20sh^~
else T5_rPz
return nextIndex; !]&+g'aC3
} M2A_T.F=H
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publicint getPreviousIndex(){ `Zci<
int previousIndex = getStartIndex() - gi8f)MNP?~
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pageSize; ~Vc`AcWP
if(previousIndex < 0) Z_Y gV:jc
return0; _ujhD
else (,RL\1zJ
return previousIndex; {G=|fgz
} hE +M|#o
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} )OFf nKh
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抽象业务类 L(HAAqRnJ
java代码: 5$*=;ls>J
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/** O
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* Created on 2005-7-12 3WPZZN<K9
*/ /WI H#M
package com.javaeye.common.business; t1!>EI`
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import java.io.Serializable; `_3Gb
import java.util.List; ?4_ME3$t
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import org.hibernate.Criteria; 3k:`7E.
import org.hibernate.HibernateException; t24.u+O
import org.hibernate.Session; W O'nW
import org.hibernate.criterion.DetachedCriteria; QF$s([
import org.hibernate.criterion.Projections; (?[%u0%_
import :{aiw?1
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org.springframework.orm.hibernate3.HibernateCallback; n -xCaq
import
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org.springframework.orm.hibernate3.support.HibernateDaoS b\UE+\a&
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upport; Y 9BKd78Y
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import com.javaeye.common.util.PaginationSupport; t* =i8`8
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public abstract class AbstractManager extends Gf-GDy\{
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HibernateDaoSupport { C-^8;xd
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privateboolean cacheQueries = false; N^'(`"J s
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privateString queryCacheRegion; jT4
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publicvoid setCacheQueries(boolean JcC2Zn6
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cacheQueries){ a._>?rVy
this.cacheQueries = cacheQueries; vJ>o9:(6
} ((6?b5[
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publicvoid setQueryCacheRegion(String E U'P
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queryCacheRegion){ m ~gc c
this.queryCacheRegion = X#ud_+6x
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queryCacheRegion; |J~A )Bw?
} +)_#j/
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publicvoid save(finalObject entity){ b .cBg.a
getHibernateTemplate().save(entity); 5
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} H?;@r1ZAn
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publicvoid persist(finalObject entity){ 9T<k|b[6
getHibernateTemplate().save(entity); "71Y{WQ
} v|nt(-JX
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publicvoid update(finalObject entity){ LKg9{0Y:
getHibernateTemplate().update(entity); tYx>?~
} )Dyyb1\)
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publicvoid delete(finalObject entity){ 5YXMnYt9
getHibernateTemplate().delete(entity); ,hCbx#h
} )4n]n:FjN
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publicObject load(finalClass entity, yp<)v(8|'
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finalSerializable id){ *~d<]U5h
return getHibernateTemplate().load m>!aI?g
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(entity, id); UGP&&A#T-
} zG<>-?q~'
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publicObject get(finalClass entity, %z-n2%
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finalSerializable id){ Wli!s~c5Fo
return getHibernateTemplate().get $v=(`=
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(entity, id); p@wtT"Y
} A%~t[ H
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publicList findAll(finalClass entity){ 9jllW[`2F
return getHibernateTemplate().find("from ;6`7
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" + entity.getName()); f2k~(@!h
} .~|[*
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publicList findByNamedQuery(finalString ~l*[=0}
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namedQuery){ )ZpMB
return getHibernateTemplate uC2qP)m,^
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().findByNamedQuery(namedQuery); 9+~1# |
} =27Z Y Z
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publicList findByNamedQuery(finalString query, )2R]KU_=g
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finalObject parameter){ {T3wOi
return getHibernateTemplate X @X`,/{X
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().findByNamedQuery(query, parameter); ucUuhS5
} LftzW{>gI"
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publicList findByNamedQuery(finalString query, y 48zsm{
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finalObject[] parameters){ peVzF'F
return getHibernateTemplate #/)U0IR)
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().findByNamedQuery(query, parameters); |lh&l<=(f
} 4r9AU mJqw
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publicList find(finalString query){ *7),v+ET
return getHibernateTemplate().find GZ.KL!,R!
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(query); +l<;?yk:;
} |j4;XaG)
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publicList find(finalString query, finalObject _FN#Vq2
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parameter){ 3
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return getHibernateTemplate().find th+LScOX
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(query, parameter); ?*cCn-|
} m21H68y
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public PaginationSupport findPageByCriteria b>nwX9Y/U
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(final DetachedCriteria detachedCriteria){ _"82W^W i
return findPageByCriteria L"(
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); v5*JBW+c*
} 2D"aAI<P
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public PaginationSupport findPageByCriteria aF.fd2k
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(final DetachedCriteria detachedCriteria, finalint au/5`
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startIndex){ GsIqUM#R
return findPageByCriteria JY$;m3h
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(detachedCriteria, PaginationSupport.PAGESIZE, Q=^TKsu
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startIndex); n^/)T3mz{
} !~Kg_*IT
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public PaginationSupport findPageByCriteria
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(final DetachedCriteria detachedCriteria, finalint 9M@,BXOt
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pageSize, LPkl16yZ
finalint startIndex){ ,m5tO
return(PaginationSupport) Bm&6
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getHibernateTemplate().execute(new HibernateCallback(){ (.kzJ\x
publicObject doInHibernate HaQox.v%
ccy q~
(Session session)throws HibernateException { @E=77Jn[px
Criteria criteria = Jl ?_GX}ZY
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detachedCriteria.getExecutableCriteria(session); Z5[g[Q
int totalCount = Ce} m_
Uf~5Fc1d =
((Integer) criteria.setProjection(Projections.rowCount LB^xdMXi
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()).uniqueResult()).intValue(); lOHW9Z
criteria.setProjection Y9B"yV
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(null); <A&Zl&^1
List items = >*$Xbj*
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criteria.setFirstResult(startIndex).setMaxResults vHb^@z=
[iC]Wh%
(pageSize).list(); .L.9e#?3
PaginationSupport ps = ?B<.d8i
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new PaginationSupport(items, totalCount, pageSize, f\H1$q\p\
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startIndex); 1eI_F8I U
return ps; N: 5 N}am
} Tb{RQ?Nw'
}, true); </W"e!?X
} @%r"7%tq>
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public List findAllByCriteria(final rGay~\
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DetachedCriteria detachedCriteria){ {5c]\{O?[
return(List) getHibernateTemplate
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().execute(new HibernateCallback(){ =tl~@~pqI
publicObject doInHibernate @IOl0db
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(Session session)throws HibernateException { Op hD_^
Criteria criteria = -:Bgp*S
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detachedCriteria.getExecutableCriteria(session); A|yU'k
return criteria.list(); \!IEZ
} P[jh^!<j
}, true); lz_ r
} c-4z8T#M^
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public int getCountByCriteria(final 6Ia[`xuL
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DetachedCriteria detachedCriteria){ CW+gZ!
Integer count = (Integer) UkC'`NWF*
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getHibernateTemplate().execute(new HibernateCallback(){ {d> 6*b
publicObject doInHibernate cvYKZB
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(Session session)throws HibernateException { l0tFj>q"
Criteria criteria = t|*UlTLm
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detachedCriteria.getExecutableCriteria(session); [C@Ro,mI
return 3V<c4'O\W
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criteria.setProjection(Projections.rowCount VOT9cP^6
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()).uniqueResult(); Y\F4
} CiTWjE?|7
}, true); 9fsc>9
return count.intValue(); Z
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} upFe{M@
} 3;R`_#t+
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用户在web层构造查询条件detachedCriteria,和可选的 ^MVOaV65
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 P=X)Ktmv
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PaginationSupport的实例ps。 U@:l~xJ
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ps.getItems()得到已分页好的结果集 _S CY e
ps.getIndexes()得到分页索引的数组 #;UoZJ B
ps.getTotalCount()得到总结果数 WN o+%
ps.getStartIndex()当前分页索引 (@S9>z4s
ps.getNextIndex()下一页索引 |I3&a=,
ps.getPreviousIndex()上一页索引 ,<[x9 "3\
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 wkT4R\H >
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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 nWUau:%
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一下代码重构了。 P#"_H}qC*
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我把原本我的做法也提供出来供大家讨论吧: ,QLy}=N
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首先,为了实现分页查询,我封装了一个Page类: Ad4-aWH
java代码: |WW'qg]Uu
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/*Created on 2005-4-14*/ ^b*ub(5Ot
package org.flyware.util.page; am/D$ (l1
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/** ?S.LGc
* @author Joa ~xc0Ky?8
* ~!_UDD
*/ <iM}p^jX9
publicclass Page { T%**:@}+
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/** imply if the page has previous page */ <lWBhrz
privateboolean hasPrePage; ~u r}6T
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/** imply if the page has next page */ !X=93%
privateboolean hasNextPage; t`1~5#?Du(
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/** the number of every page */ Qd}h:U^
privateint everyPage; '(8}
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/** the total page number */ jjg&C9w T
privateint totalPage; X$ A ]7t
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/** the number of current page */ g5
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privateint currentPage; >jc17BJq
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/** the begin index of the records by the current %}{.U
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query */ c43&[xPLz
privateint beginIndex; q4Y'yp`?K;
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/** The default constructor */ pzU:AUW
public Page(){ 'JAe=K
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} mQ\oR|
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/** construct the page by everyPage r6kQMFA
* @param everyPage N
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* */ i^eDM.#X
public Page(int everyPage){ ~Yg+bwh
this.everyPage = everyPage; 0:eK}tC
} b =:%*gq,
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/** The whole constructor */ ^_o:Ddz?l"
public Page(boolean hasPrePage, boolean hasNextPage, = Ruq
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int everyPage, int totalPage, KzB9
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int currentPage, int beginIndex){ bbWW|PtWwP
this.hasPrePage = hasPrePage; W}k)5<C4v
this.hasNextPage = hasNextPage; kqLpt
this.everyPage = everyPage; [O6JVXO>
this.totalPage = totalPage; "mcuF]7F
this.currentPage = currentPage; _61tE
this.beginIndex = beginIndex; [V;Q#r&+
} G)%r|meKGB
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/** !XY}\zKq
* @return NaeG)u#+
* Returns the beginIndex. S?Uvt?
*/ u6*mHkM
publicint getBeginIndex(){ ['l}*
return beginIndex; dj3E20Ws
} a<Ps6'
z!^3%kJJ>
/** T2 V(P>E
* @param beginIndex /fxv^C82yv
* The beginIndex to set. -yY]0
*/ ?gS~9jgcd
publicvoid setBeginIndex(int beginIndex){ u~27\oj,
this.beginIndex = beginIndex; ~<=wTns!
} 8uB6C0,6?
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/** M532>+A]Za
* @return *)i+ c{~
* Returns the currentPage. MG$Df$R
*/ 0j[%L!hny
publicint getCurrentPage(){ @34CaZ$k
return currentPage; <Kq!)) J'
} -)E6{
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/** $9<P3J 1
* @param currentPage 9K#U<Q0b'
* The currentPage to set. )7iYx {n
*/ 2tdr1+U?g
publicvoid setCurrentPage(int currentPage){ 9icy&'
this.currentPage = currentPage; ['@R]Si"!
} efm#:>H
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/** [\)irCDv
* @return gOn^}%4.I
* Returns the everyPage. $:*/^)L
*/ *iujJi
publicint getEveryPage(){ ]q@W(\I
return everyPage; MJ`BlE,Fmb
} zY\MzhkX,
| PzXN+DW
/** 6s&%~6J,
* @param everyPage c +]5[6
* The everyPage to set. +q)B4A'J!
*/ 'M3V#5l)@|
publicvoid setEveryPage(int everyPage){ SWMi+)
this.everyPage = everyPage; mV'^4by
} I$1~;!<
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/** {b26DKkQS
* @return 3AarRQWsn
* Returns the hasNextPage. 1EA} [x
*/ m-}6DN
publicboolean getHasNextPage(){ ZbLN:g}
return hasNextPage; _iW-i
} /Wm3qlv
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/** (khMjFOg
* @param hasNextPage {#uf#J|
* The hasNextPage to set. 5\P3JoH:Yg
*/ ~er4w+"
publicvoid setHasNextPage(boolean hasNextPage){ h%(0|
this.hasNextPage = hasNextPage; HXRK<6k$
} MNsgD3
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/** ewzZb*\
* @return mi$*,fz
* Returns the hasPrePage. ~JxAo\2i
*/ #kL4Rm;
publicboolean getHasPrePage(){ &oqzQ+H
return hasPrePage; UNd+MHE74I
} &io*pmUm6
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/** )l*6zn`z
* @param hasPrePage YNWAef4
* The hasPrePage to set. EXTQ:HSES
*/ O=wu0n
publicvoid setHasPrePage(boolean hasPrePage){
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this.hasPrePage = hasPrePage; nV+]jQ~o
} _.$g ?E/(
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/** P
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* @return Returns the totalPage. 5nJmabw3
* XKT2u!Lx
*/ L#NW<T
publicint getTotalPage(){ V/i7Z h#2:
return totalPage; !Typ_Cs
} vaUUesytt
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/** 'CO3b,
* @param totalPage :p,DAt}
* The totalPage to set. Zp*0%x!e
*/ F
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publicvoid setTotalPage(int totalPage){ 7Yd]#K{$
this.totalPage = totalPage; {`CmE/`{
} E0Jk=cq
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} yu]nK-Y7S
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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 ]
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个PageUtil,负责对Page对象进行构造: 4w-P%-4
java代码: 9Wi+7_)
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/*Created on 2005-4-14*/ 5 NdIbC
package org.flyware.util.page; iH""dtO
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import org.apache.commons.logging.Log; 0"to]=
import org.apache.commons.logging.LogFactory; &lYe
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/** xnm!$ $W
* @author Joa +HOHu*D
* b];? tP
*/ F/I`EV
publicclass PageUtil { @$(@64r
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privatestaticfinal Log logger = LogFactory.getLog `;fk,\8t%
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(PageUtil.class); z4yV1
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/** j?
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* Use the origin page to create a new page ^6U0n!nU
* @param page M8wEy_XB1
* @param totalRecords gr
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* @return ;3H#8x-
*/ *n h.&Mv|
publicstatic Page createPage(Page page, int 2gnmk
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totalRecords){ Z#P:C":e
return createPage(page.getEveryPage(), -N]%)Hy
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page.getCurrentPage(), totalRecords); (jY -MF3
} ,:1_I`d>#X
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/** [nnX,;
* the basic page utils not including exception j[Xci<m
\P` mV9P
handler aV'r
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* @param everyPage 2PSt*(
* @param currentPage [C"[#7
* @param totalRecords S=bdue
* @return page ^Gs=U[**
*/ %[9d1F3
publicstatic Page createPage(int everyPage, int ~HH6=qjU)
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currentPage, int totalRecords){ <(U:v
everyPage = getEveryPage(everyPage); :UgCP ~Y
currentPage = getCurrentPage(currentPage); 2l9RU}
int beginIndex = getBeginIndex(everyPage, xEfz AJ5&
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currentPage); $J]b+Bp
int totalPage = getTotalPage(everyPage, ]7ZY|fP2
c<gvUVHIxR
totalRecords); _PR><L_
boolean hasNextPage = hasNextPage(currentPage, OAhCW*B
Fl'+ C
totalPage); sC=fXCGW\p
boolean hasPrePage = hasPrePage(currentPage); #nS
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returnnew Page(hasPrePage, hasNextPage, jg_##Oha
everyPage, totalPage,
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currentPage, ,ruL7|T&
u(!@6%?-
beginIndex); J^R#
} L,B#%t
aF~ 0\XC
privatestaticint getEveryPage(int everyPage){ &b#O=LF
return everyPage == 0 ? 10 : everyPage; ))qOsphN
} 4x'N#m{p
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privatestaticint getCurrentPage(int currentPage){ UmRI! WQl
return currentPage == 0 ? 1 : currentPage; #6%9*Rh
} ^l(Kj3gM
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privatestaticint getBeginIndex(int everyPage, int Mk -Rl
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currentPage){ pg%'_+$~m
return(currentPage - 1) * everyPage; 0rtP :Nj$
} 85Hb~|0
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privatestaticint getTotalPage(int everyPage, int zu~E}
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totalRecords){ /5y*ZIq]e
int totalPage = 0; OEN!~-u
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if(totalRecords % everyPage == 0) w/`I2uYu
totalPage = totalRecords / everyPage; f.4m6"1
else _k,/t10
totalPage = totalRecords / everyPage + 1 ; ^\X-eeA
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return totalPage; Y0||>LX
} n' \poB?
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privatestaticboolean hasPrePage(int currentPage){ QQ5G?E
return currentPage == 1 ? false : true; Y!8Ik(/~i
} -2dk8]KB]
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privatestaticboolean hasNextPage(int currentPage, ) DzbJ}
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int totalPage){ ]y:ez8RFPU
return currentPage == totalPage || totalPage == YuZxKuGy
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0 ? false : true; XCGJ~
} MMpGI^x!-X
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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。 /GK1}h
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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 SYPG.O?I
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做法如下: 7n-;++a5]
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 b`@aiXN)+
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的信息,和一个结果集List: P+m{hn~%
java代码: Hq{i-z+
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/*Created on 2005-6-13*/ 6d RxfbL
package com.adt.bo; cI9} YSk
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import java.util.List; +w
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import org.flyware.util.page.Page; @w)Vt$+b]
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/** 0i[,`>-Av
* @author Joa z*cC2+R}=
*/ p*T`fOL
publicclass Result { <5s51b <
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private Page page; ~mqiXr8
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private List content; `wJR^O!e
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/** HMQi:s7%
* The default constructor q1Ja*=r
*/ ?h;Zdv>`xz
public Result(){ &*wN@e(c
super(); @O7hY8",
} 0]C~CvO
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/** ZgN )sVJ
* The constructor using fields 87Sqs1>cw
* cr{;gP
* @param page +ht -Bl
* @param content <<zYF.9L]
*/ (p2jigP7a[
public Result(Page page, List content){ XY[uyR4Z
this.page = page; vI<n~FHt
this.content = content; ,4bqjkX5q
} "T`Q,
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/** H'fmQf
* @return Returns the content. b<