Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 K;L6<a A#
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 c^F@9{I
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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 lZ'ZL*
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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 SJ7-lben3
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。 }q?*13iy(
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分页支持类: -`cNRd0n
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java代码: uY;7&Lw
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package com.javaeye.common.util; MwE^.6xl{
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import java.util.List; INNTp[
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publicclass PaginationSupport { Sp-M:,H3H
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publicfinalstaticint PAGESIZE = 30; /P[ @o
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privateint pageSize = PAGESIZE; &Db'}Y?x]
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privateList items; rCsH
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privateint totalCount; O_P8OA#|
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privateint[] indexes = newint[0]; %df[8eX{
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privateint startIndex = 0; 7e/K YS+!s
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public PaginationSupport(List items, int eMOnzW|h
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totalCount){ AcIw;
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setPageSize(PAGESIZE); +kM*BCPYE
setTotalCount(totalCount); ' p!\[*e
setItems(items); 8;fi1 "F;}
setStartIndex(0); V_P,~!
} dk.VH!uVb
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public PaginationSupport(List items, int ^~DClZ
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totalCount, int startIndex){ 2X`5YN;
setPageSize(PAGESIZE); /rzZU} 3[
setTotalCount(totalCount); m<GJ1)%3i
setItems(items); _<7e5VR
setStartIndex(startIndex); &-(p~[|
} B'-L-]\H
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public PaginationSupport(List items, int ,7^,\ ,-m
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totalCount, int pageSize, int startIndex){ Z:Nm9m
setPageSize(pageSize); &)F#cVB
setTotalCount(totalCount); [8rl{~9E
setItems(items); ]7
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setStartIndex(startIndex); 0RkiD8U5
} BLcsIyq
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publicList getItems(){ Z)dE#A_X
return items; ['\u?m
} tN&_f==e
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publicvoid setItems(List items){ ALl0(<u67
this.items = items; F'3-*>]P
} x[1(cj
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publicint getPageSize(){ WG(%Pkowv
return pageSize; ;&U! g&
} Q\{$&0McF
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publicvoid setPageSize(int pageSize){ [y1
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this.pageSize = pageSize; Bw8&Amxx:
} hwB>@r2
2` j#eB1
publicint getTotalCount(){ k5TPzm=y{
return totalCount; OVf%m~%&s
} e=w.7DSE
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publicvoid setTotalCount(int totalCount){ h;`]rK;g
if(totalCount > 0){ xH/Pw?^
this.totalCount = totalCount; /{+77{#Qn
int count = totalCount / J<=k
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pageSize; {wyf>L0j
if(totalCount % pageSize > 0) LSN%k5G7.
count++; t}2$no?
indexes = newint[count]; fY{&W@#g
for(int i = 0; i < count; i++){ ? bnhx
indexes = pageSize * {5N!udLDr5
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i; Y~ ( <H e?
} ]eD5It\
}else{ nlaeo"]
this.totalCount = 0; kEpCF:@A
} XVNJ3/
} *>f-UNV
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publicint[] getIndexes(){ 6pi^ rpo
return indexes; 0'O*Y
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} =zXii{t
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publicvoid setIndexes(int[] indexes){ 4_B1qN
this.indexes = indexes; aO]FQ#l2b
} K
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publicint getStartIndex(){ D%=FCmL5@=
return startIndex; g<"k\qs7
} uY'77,G_J
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publicvoid setStartIndex(int startIndex){ S0uEz;cE
if(totalCount <= 0) !p#+I=
this.startIndex = 0; /"*eMe!=
elseif(startIndex >= totalCount) _>"f&nbO
this.startIndex = indexes GI40Ztms
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[indexes.length - 1]; :-Al}7
elseif(startIndex < 0) v1Wz#oP
this.startIndex = 0; 16N+
else{ WMw]W&
this.startIndex = indexes MU/3**zoW
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[startIndex / pageSize]; CYCG5)<9
} L[s8`0
} %oY=.Ok ]
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publicint getNextIndex(){ vuCl(/P`
int nextIndex = getStartIndex() + *He%%pk
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pageSize;
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if(nextIndex >= totalCount) #mDeA >b
return getStartIndex(); cii]-%J}c
else M
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return nextIndex; klKd !
} u{_jweZ
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publicint getPreviousIndex(){ h*JzJ0X
int previousIndex = getStartIndex() - />,Tq!i\4}
SpB\kC"K
pageSize; W$X@DXT=o
if(previousIndex < 0) \&S-lsLY
return0;
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else ;F:~HrxT}
return previousIndex; =gjq@N]lAW
} S)h0@;q
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} jbU=D:|
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抽象业务类 3Wl,T5}{
java代码: ]$VYzE2e
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/** UJWkG^?
* Created on 2005-7-12 8.'[>VzBL
*/ q|23l1PI
package com.javaeye.common.business; 1JIo,7
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import java.io.Serializable; A"`^Abrm
import java.util.List; |QIFtdU5T
3bGJ?hpp
import org.hibernate.Criteria; mx'!I7b(L/
import org.hibernate.HibernateException; Qmk}smvH
import org.hibernate.Session; 0xe!tA
import org.hibernate.criterion.DetachedCriteria; {4@+
2)l
import org.hibernate.criterion.Projections; *nPB+@f
import DD4fV`:kG
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org.springframework.orm.hibernate3.HibernateCallback;
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import }c"1;C&{
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org.springframework.orm.hibernate3.support.HibernateDaoS .=nx5yz
![{>$Q?5
upport; ;B'5B]A3
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import com.javaeye.common.util.PaginationSupport; z`^DQ8+\j
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public abstract class AbstractManager extends g@<E0
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HibernateDaoSupport { krw_1Mm
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privateboolean cacheQueries = false; Dj~]]
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privateString queryCacheRegion; y$]gmg
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publicvoid setCacheQueries(boolean TaZw_)4c
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cacheQueries){ @Y~R*^n"}
this.cacheQueries = cacheQueries; yJheni
}
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publicvoid setQueryCacheRegion(String \1AtBc&
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queryCacheRegion){ x*EzX4$x
this.queryCacheRegion = _msV3JBr
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queryCacheRegion;
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} PMdvBOtS`
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publicvoid save(finalObject entity){ *6-f vqCv
getHibernateTemplate().save(entity); : DxCjv
} hr+,-j
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publicvoid persist(finalObject entity){ qm.30 2
getHibernateTemplate().save(entity); +EmT+$>J
} nj (/It
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publicvoid update(finalObject entity){ {EoRY/]
getHibernateTemplate().update(entity); #q06K2
} uA}w?;
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publicvoid delete(finalObject entity){ jL|y4
getHibernateTemplate().delete(entity); ?HP54G<{xz
} 5&y;r
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publicObject load(finalClass entity, zH1pW(
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finalSerializable id){ gbf-3KSp^
return getHibernateTemplate().load MpV3.
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(entity, id); \WDL?(G<
} $Vi[195]2
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publicObject get(finalClass entity, )w{bT]
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finalSerializable id){ !s>AVV$;0
return getHibernateTemplate().get !T((d7;
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(entity, id); 6N{Vcfq
} P <$)v5f
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publicList findAll(finalClass entity){ ];-DqK'
return getHibernateTemplate().find("from qfO=_z ES
^1a/)Be{_
" + entity.getName()); PY4RwN
} ad\?@>[I
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publicList findByNamedQuery(finalString -:hiLZJ7-
<K~> :4c
namedQuery){ 9 >t
return getHibernateTemplate 9@Iz:!oqb
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().findByNamedQuery(namedQuery); AhZ`hj
} h6*&1r
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publicList findByNamedQuery(finalString query, %uuh+@/&yz
)JO#Z(
finalObject parameter){ d},IQ,Az:Z
return getHibernateTemplate F-\Swbx+
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().findByNamedQuery(query, parameter); J3]!<v=
} V~Zi #o
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publicList findByNamedQuery(finalString query, h,Y!d]2w
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finalObject[] parameters){ yGNZw7^(
return getHibernateTemplate uCc.dluU
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().findByNamedQuery(query, parameters); r'kUU]j9
} cTA8F"UGD
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publicList find(finalString query){ e}x}Fj</(
return getHibernateTemplate().find *K9I+t"g
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(query); S$CO T)7
} z7[TgL7
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publicList find(finalString query, finalObject nkKiYr
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parameter){ )'<B\P/
return getHibernateTemplate().find ^2gDhoO_
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(query, parameter);
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} xW$F-n
t/;@~jfr@
public PaginationSupport findPageByCriteria \m.ap+dFa
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(final DetachedCriteria detachedCriteria){ /`M>3q[
return findPageByCriteria H-?wEMi)*u
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); W\(u1>lj
} +3HukoR(
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public PaginationSupport findPageByCriteria u!k]Q#2ZR
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(final DetachedCriteria detachedCriteria, finalint \JJ>y
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startIndex){ 0jS"PH?[
return findPageByCriteria ]r#YU0
- nWs@\
(detachedCriteria, PaginationSupport.PAGESIZE, :NB,Dz+i
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startIndex); XA
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} ep"YGx[V
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public PaginationSupport findPageByCriteria GVFR^pzO
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(final DetachedCriteria detachedCriteria, finalint vepZod}D
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pageSize, x^UE4$oo
finalint startIndex){ `w_?9^7mH
return(PaginationSupport) 4T*RJ3Fz!
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getHibernateTemplate().execute(new HibernateCallback(){ r]XXN2[jO
publicObject doInHibernate 5e!YYt>
@ljvTgZ(X
(Session session)throws HibernateException { %ZNp
Criteria criteria = -1tdyCez
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detachedCriteria.getExecutableCriteria(session); |!r.p_Zt
int totalCount = N=qe*Rlf
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((Integer) criteria.setProjection(Projections.rowCount NF&
++Vr6
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()).uniqueResult()).intValue(); %5X}4k!p
criteria.setProjection go, Hfb
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(null); rm7$i9DH2
List items = &&iZ?JteZ
8\Y/?$on
criteria.setFirstResult(startIndex).setMaxResults xy@1E;
n@LR?
(pageSize).list(); K^V*JH\G
PaginationSupport ps = {HV$hU+_)Q
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new PaginationSupport(items, totalCount, pageSize, P!?Je/Tz]
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startIndex); hcQvL>
return ps; ap;tggi(H
} zVLv-U/=d
}, true); ?[4!2T,Ca
} Ua.7_Em
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public List findAllByCriteria(final u-W6 hZ$
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DetachedCriteria detachedCriteria){ -+1it
return(List) getHibernateTemplate ^*7~ Wxk5
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().execute(new HibernateCallback(){ 32_{nLV$[
publicObject doInHibernate \`w!v,aM$
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(Session session)throws HibernateException { !Jo3>!,j
Criteria criteria = dzYB0vut@
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detachedCriteria.getExecutableCriteria(session); =*q|568
return criteria.list(); lVywc:X
} 4\HB rd#P
}, true); h&7]Bp
} [3a-1,
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public int getCountByCriteria(final AL.zF\?
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DetachedCriteria detachedCriteria){ xF)AuGdp\
Integer count = (Integer) *_<P%J
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getHibernateTemplate().execute(new HibernateCallback(){ ;!<WL@C~
publicObject doInHibernate Wt +,6Cq
aq[ ;[$w
(Session session)throws HibernateException { m1 78S3
Criteria criteria = S7-ka{S
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detachedCriteria.getExecutableCriteria(session); Jtj_Rl
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return W_EM
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criteria.setProjection(Projections.rowCount (7RxCo=X
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()).uniqueResult(); g-=)RIwm
} tt=?*n
}, true); H'myd=*h~8
return count.intValue(); 6KiI3%y?0
} Xtqjx@ye
} T ,,
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用户在web层构造查询条件detachedCriteria,和可选的 _W 41;OY
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ![WX -"lW
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PaginationSupport的实例ps。 DG8LoWZ
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ps.getItems()得到已分页好的结果集 k%\_UYa
ps.getIndexes()得到分页索引的数组 **rA/*Oc
ps.getTotalCount()得到总结果数 `"v5bk
ps.getStartIndex()当前分页索引 .BGM1ph}~
ps.getNextIndex()下一页索引 "|CzQ&e
ps.getPreviousIndex()上一页索引 *F+t`<2
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ~LPxVYhK
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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 -;_`>OU{
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一下代码重构了。 <8MKjf
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我把原本我的做法也提供出来供大家讨论吧: 27*u^N*z@
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首先,为了实现分页查询,我封装了一个Page类: Ec| Gom?
java代码: q10gKVJum
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/*Created on 2005-4-14*/ &| %<=\
package org.flyware.util.page; .lfKS!m2
ud K)F$7
/** 'v^CA}
* @author Joa c[]_gUp8
* d3h2$EDD
*/ U'S}7gya
publicclass Page { ]Q=D'1MM
k"|4
LPv[
/** imply if the page has previous page */ '3Yci(t+
privateboolean hasPrePage; I|lz;i}$
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/** imply if the page has next page */ Zrp`91&I
privateboolean hasNextPage; 6_/691
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/** the number of every page */ Tl=cniy]
privateint everyPage; 0!F"s>(H
!%x8!;za
/** the total page number */ W R@=[G#TJ
privateint totalPage; h5WS<P
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/** the number of current page */ e{8z1t20:
privateint currentPage; T9]|*~ ,T
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/** the begin index of the records by the current x\r7q
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query */ ]Mi
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privateint beginIndex; ?P[uf
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/** The default constructor */ GHeJpS
public Page(){ jr{C/B}
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} f7 V3 6Q8
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/** construct the page by everyPage -}0S%|#m
* @param everyPage ,wE]:|`qJ
* */ 8<M'~G%CEq
public Page(int everyPage){ mh]'/C_*<w
this.everyPage = everyPage; 8R Wfv}:X
} GwxxW
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/** The whole constructor */ }$3eRu +
public Page(boolean hasPrePage, boolean hasNextPage, yC !`6$
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int everyPage, int totalPage, ]&\HAmOQS
int currentPage, int beginIndex){ fv_}7t7
this.hasPrePage = hasPrePage; {]<l|qK
this.hasNextPage = hasNextPage; zu'Uau
this.everyPage = everyPage; Ql
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this.totalPage = totalPage; =8$//$
this.currentPage = currentPage; | 2BIAm]
this.beginIndex = beginIndex; q%TWtQS
} &Yi)|TU3'R
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/** Y~Y-L<`I
* @return ^pZ1uN!b
* Returns the beginIndex. D'Tb=
*/ $9<q'hf<w
publicint getBeginIndex(){ <uUQ-]QOIh
return beginIndex; yjUZ40Dq
} Ov"]&e(I[
=3OK3|
/** km2('t7?
* @param beginIndex ;LE4U OK
* The beginIndex to set. }r$&"wYM
*/ q65KxOf`
publicvoid setBeginIndex(int beginIndex){ K:
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this.beginIndex = beginIndex; Nq1la8oQ3
} }#'wy
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/** =gS?atbX
* @return J#vIzQ
* Returns the currentPage. Vy0s%k
*/ M*FUtu
publicint getCurrentPage(){ P:h;"
return currentPage; J$
} `<!Nk^2ap
exw~SvT3
/** ,gGIkl&
* @param currentPage t-Rfy`I3
* The currentPage to set. D7|[:``
*/ h\\fb[``
publicvoid setCurrentPage(int currentPage){ qd#?8
this.currentPage = currentPage; qp_lMz
} .gTla
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/** Pe6}y
* @return "*W:
* Returns the everyPage. 2^w3xL"
*/
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publicint getEveryPage(){ H,`F%G#!`q
return everyPage; $Llv6<B
} -SZXUN
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/** 7S$Am84%
* @param everyPage "s!!\/^9C
* The everyPage to set. 52?zBl`|
*/ 1=(jpy
publicvoid setEveryPage(int everyPage){ c* 2U'A
this.everyPage = everyPage; n%zW6}
} 1Q\P]
-
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/** sC
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* @return [ZC]O2'
* Returns the hasNextPage. ir/m.~?
*/ -F=?M+9[
publicboolean getHasNextPage(){ VuA7rIF$66
return hasNextPage; k7JE{(Ok
} 4?Pdld
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/** gU\pP,a
* @param hasNextPage CXt9 5O?
* The hasNextPage to set. %@tKcQ
*/ Cbu/7z
publicvoid setHasNextPage(boolean hasNextPage){ !>QS746S@
this.hasNextPage = hasNextPage; fB^h2
} xIu#
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/** M)S(:Il6Xx
* @return z~&uLu
* Returns the hasPrePage. Aq'yr,
*/ zh`!x{Z?^
publicboolean getHasPrePage(){ 8:=&=9%
return hasPrePage; mdjPKrF<
} &*2\1;1tB
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/** AsFn%8_I
* @param hasPrePage _CqVH5U?
* The hasPrePage to set. oSVo~F
*/ @>`+eg][?P
publicvoid setHasPrePage(boolean hasPrePage){ <vMna< /d
this.hasPrePage = hasPrePage; K$v
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} rEz-\jLD~
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/** o6`4y^Q{/
* @return Returns the totalPage. c%1k'Q
* @}[ >*Xy%
*/ Mx9#YJ?t~
publicint getTotalPage(){ PWeCk2 xH
return totalPage; sF9{(Us
} +&hhj~I.
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/** _)|_KQQu
* @param totalPage BGM5pc (ei
* The totalPage to set. .*XELP=BT
*/ EUBJnf:q
publicvoid setTotalPage(int totalPage){ CTawXHM
this.totalPage = totalPage; Q{%2Npvq
} dRwOt
:"m~tU3&
} (w4w
y8} fj=
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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 4I7B
#{
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个PageUtil,负责对Page对象进行构造: rJLn=|uR
java代码: 3V=(P.A Tm
aq~>$CHa
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/*Created on 2005-4-14*/ t][U`1>i
package org.flyware.util.page; $ti*I;)h4
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import org.apache.commons.logging.Log; L{`S^'P<
import org.apache.commons.logging.LogFactory; 5mzOr4*0
&UzeNL"]
/** :`u?pc27Sm
* @author Joa WFWQ;U{|
* ^gw htnI
*/ [6 d~q]KH
publicclass PageUtil { ^RL#(O
nc<wDE6
privatestaticfinal Log logger = LogFactory.getLog 5x$/.U
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(PageUtil.class); LDg"s0n#
.'`7JU#{
/** R Lnsy,
* Use the origin page to create a new page "53'FRj_\
* @param page eKRslMa
* @param totalRecords t "y[
* @return v[$-)vs*ag
*/ C]@v60I
publicstatic Page createPage(Page page, int :r4]8X-
3[q&%Z.
totalRecords){ 0cYd6u@
return createPage(page.getEveryPage(), 3=[#(p:
W&M=%
page.getCurrentPage(), totalRecords);
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} eZ>KA+C[
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/** ^b{ -y
* the basic page utils not including exception 7RXTQ9BS
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handler \VY!= 9EV
* @param everyPage n oWjZ
* @param currentPage }E
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* @param totalRecords PK&3nXF%4
* @return page C\-Abqc
*/ By3y.}'Ub9
publicstatic Page createPage(int everyPage, int L >*
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currentPage, int totalRecords){ 9gu$vF]9!
everyPage = getEveryPage(everyPage); w$5~'Cbi
currentPage = getCurrentPage(currentPage); !v/j*'L<M}
int beginIndex = getBeginIndex(everyPage, GUX!kj
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currentPage); $O\I9CGr$
int totalPage = getTotalPage(everyPage, >Xz=E0;^Ua
? PIq/[tk
totalRecords); hMcSB8 ?
boolean hasNextPage = hasNextPage(currentPage, `2WtA_
^Rel-=Z$B
totalPage); ^{ Kj{M22
boolean hasPrePage = hasPrePage(currentPage); rTJ='<hIy
wEQ7=Gyx
returnnew Page(hasPrePage, hasNextPage, M<Gr~RKmAn
everyPage, totalPage, V)pn)no'V
currentPage, #sHA!@ |
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beginIndex); 0LX"<~3j
} Sn o7Ru2
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privatestaticint getEveryPage(int everyPage){ BIu%A]e"
return everyPage == 0 ? 10 : everyPage; @ve4rc/LI
} @M]uUL-ze
$ 12mS
privatestaticint getCurrentPage(int currentPage){ ;Avz%2#c`
return currentPage == 0 ? 1 : currentPage; YwbRzY-#F
} d]3c44kkK{
Yg @&@S]
privatestaticint getBeginIndex(int everyPage, int 6}V)\"u&
4=;.<
currentPage){ XwZ~pY ~
return(currentPage - 1) * everyPage; WO}l&Q
} {|R@\G.1(
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privatestaticint getTotalPage(int everyPage, int |3Fo4K%+
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totalRecords){ VXE85
int totalPage = 0; \vH /bL
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if(totalRecords % everyPage == 0) >M}\_c=
totalPage = totalRecords / everyPage; | c:E)S\
else R04%;p:k#
totalPage = totalRecords / everyPage + 1 ; 9S<87sO
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return totalPage; PIZnzZ@Z;
} bCV3h3<
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privatestaticboolean hasPrePage(int currentPage){ MC
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return currentPage == 1 ? false : true; 5}
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} 'ycr/E&m{
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privatestaticboolean hasNextPage(int currentPage, t)#dR._q
G,{=sFX
int totalPage){ OpNTyKbaD
return currentPage == totalPage || totalPage == S":55YQev!
#!A'6SgbkM
0 ? false : true; qw#wZ'<n
} Fwu:x.(
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} U<pGP
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&-S;.}
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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。 "7> o"FQ
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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 rE&`G[(b
)2nx5"
做法如下: D.!ay>o0#
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 5B|&+7dCw
P!6v0ezN
的信息,和一个结果集List: (0wQ [(
java代码: "e3T;M+
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31y>/*}
/*Created on 2005-6-13*/ x4_xl
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package com.adt.bo; >5O#_?
zeC@!,lH
import java.util.List; Z(|@C(IL0\
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import org.flyware.util.page.Page; a/4!zT
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/** 0h3-;%
* @author Joa tRUGgf`
*/ K)D5%?D
publicclass Result { t PJW|wo
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private Page page; hJ)\Vo
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private List content; =6sA49~M
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/** A`#/:O4|f
* The default constructor 7Gos-_s
*/ >V01%fLd
public Result(){ I^u$H&
super(); !,SGKLs.m
} Q;V*M
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/** >`0l"K<
* The constructor using fields Gz_[|,i
* &7fwYV
* @param page EMTAl;P
* @param content MV(Sb:RZ
*/ fwN'5ep
public Result(Page page, List content){ 6Mh;ld@
this.page = page; F2N)|C<
this.content = content; >*wF~G*k
} 1"hd5a
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/** D*nNu]|j
* @return Returns the content. .uoQ@3
*/ 7A@iu*t
publicList getContent(){ b|rMmx8vA
return content; dj;Zzt3
} ZH1W#dt`[
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/** \ZOH3`vq
* @return Returns the page. lDWg%pI+
*/ G
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public Page getPage(){ San=E@3}v!
return page; sC<
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} }C'H@:/
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/** aFbIJm=!
* @param content 3IlflXb
* The content to set. +=N!37+G
*/ ask76
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public void setContent(List content){ qH8d3?1XO
this.content = content; TwaK>t96[
} &