Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Z4!3I@yZ
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 *Tlv'E.M
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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 8dH|s#.4um
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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 Txh;r.1e
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分页支持类:
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java代码: 'zb7:[[7%
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package com.javaeye.common.util; K0\WN"ua;
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import java.util.List; AL0Rn e N
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publicclass PaginationSupport { nM`) `!/
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publicfinalstaticint PAGESIZE = 30; 1|VJN D
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privateint pageSize = PAGESIZE; kXr%73s
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privateList items; .vO.g/o
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privateint totalCount; pA'A<|)K0
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privateint[] indexes = newint[0]; >$DqG$D
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privateint startIndex = 0; d3GK.8y_z
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public PaginationSupport(List items, int :3f2^(b~^
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totalCount){ 8GldVn.u
setPageSize(PAGESIZE); {P&^Erx
setTotalCount(totalCount); Pc'?p
setItems(items); QGd- 9UEA]
setStartIndex(0); [JoTWouNU
} w>uZ$/
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public PaginationSupport(List items, int DOe KW
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totalCount, int startIndex){ "N]o5d
setPageSize(PAGESIZE); 5H+k_U
setTotalCount(totalCount); )*h~dx_c m
setItems(items); LltguNM$
setStartIndex(startIndex); AvZ) 1(
} N_D+d4@
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public PaginationSupport(List items, int u9w&q^0dqG
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totalCount, int pageSize, int startIndex){ .5;LL,S-
setPageSize(pageSize); a}fClI-u
setTotalCount(totalCount); I!gj; a?R
setItems(items); `Xdxg\|
setStartIndex(startIndex); ~uadivli
}
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publicList getItems(){ f<Tz#w&6W
return items; dM{~Ubb
} $3[\:+
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publicvoid setItems(List items){ +wozjjc
this.items = items; 8? Wxd65)
} ?7)(qnbe"
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publicint getPageSize(){ Ir"Q%>K0f
return pageSize; '<< ~wt
} p''"E$B/(
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publicvoid setPageSize(int pageSize){ ;+34g6
this.pageSize = pageSize; P<!$A
} C_cs(}wi
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publicint getTotalCount(){ AAq=,=:R<
return totalCount; cO+Xzd;838
} 9<h]OXv
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publicvoid setTotalCount(int totalCount){ l@rwf$-
if(totalCount > 0){ V!77YFen %
this.totalCount = totalCount; M#VC3h$
int count = totalCount / dIpW!Pj^
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pageSize; PuZs5J3
if(totalCount % pageSize > 0) GyAgPz
count++; .um&6Q=2<
indexes = newint[count]; 1Uemsx%'k
for(int i = 0; i < count; i++){ 15KV}){
indexes = pageSize * N1N{Ol'
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i; T<+ht8&M8
} ct}%Mdg
}else{ xD GS`U
this.totalCount = 0; r}0C8(oq
} Np<s[dQ
} y(nsyA
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publicint[] getIndexes(){ !Wixs]od
return indexes; /pN'K5@
} %8bzs?QI
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publicvoid setIndexes(int[] indexes){ xshArJ&A
this.indexes = indexes; )nNCB=YF!
} }B=qH7u.K
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publicint getStartIndex(){ ,9Z2cgXwJ
return startIndex; t1w2u.]
} @q+cmJKv
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publicvoid setStartIndex(int startIndex){ Du^x=;
if(totalCount <= 0) n</k/Mk}
this.startIndex = 0; R+{^@M&
elseif(startIndex >= totalCount) >v1 y 0zx
this.startIndex = indexes ,](v?v.[4
=_8
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[indexes.length - 1]; #dZ/UM(u
elseif(startIndex < 0) \5Vp6^
this.startIndex = 0; L19MP
else{ Nmp>UE,7[
this.startIndex = indexes 5#0A`QO
YX ;n6~y
[startIndex / pageSize]; $5lW)q A
} Km)X_}|
} ]*2EK9<
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publicint getNextIndex(){ TBZ-17+
int nextIndex = getStartIndex() +
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h; 'W :P
pageSize; wJ+U[a
if(nextIndex >= totalCount) m~u|VgD
return getStartIndex(); ORowx,(hX
else cQT1Xi
return nextIndex; xLx"*jyL
} v"u7~Dw#1
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publicint getPreviousIndex(){ %z*29iKlI
int previousIndex = getStartIndex() - XzT78
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pageSize; cz2,",+~
if(previousIndex < 0) -<Jq
return0; ,b4):{
else )xB$LJM8
return previousIndex; 2m_'z
} Bv^+d\*1
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} B?SNea,I4
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抽象业务类 jCzGus!rM
java代码: Q[M (Wqg
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/** 7))\'\
* Created on 2005-7-12 'WK;$XQ
*/ VCjq3/[_
package com.javaeye.common.business; 7_DG 5nT
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import java.io.Serializable; +UzXN$73
import java.util.List; f'&GFL=c
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import org.hibernate.Criteria; & g:%*>7P
import org.hibernate.HibernateException; ]}kI)34/
import org.hibernate.Session; e^QVn\<c
import org.hibernate.criterion.DetachedCriteria; EY kj@
.,
import org.hibernate.criterion.Projections; :cy>c2
import 4r\*@rq
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org.springframework.orm.hibernate3.HibernateCallback; PWvSbn6
import \eQla8s
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org.springframework.orm.hibernate3.support.HibernateDaoS Bz+.Qa+
)\wuesAO
upport; Edw2W8
# :#M{1I
import com.javaeye.common.util.PaginationSupport; 1 tPVP
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public abstract class AbstractManager extends T"?Y5t`(
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HibernateDaoSupport { .s2$al
[ "a"x>X&
privateboolean cacheQueries = false; GW3>&j_!d
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privateString queryCacheRegion; $Jp~\_X
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publicvoid setCacheQueries(boolean wK ?@.l)u
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cacheQueries){ /kB|1gFj
this.cacheQueries = cacheQueries; H\E7o"m
} _({@B`N}
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publicvoid setQueryCacheRegion(String X&a:g
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queryCacheRegion){ *%\mZ,s"
this.queryCacheRegion = #6=MKpR
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queryCacheRegion; cJDd0(tD!
} ~~nqU pK?v
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publicvoid save(finalObject entity){ 2.-o@im0
getHibernateTemplate().save(entity); T#EFXHPr
} &gn-Wb?
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publicvoid persist(finalObject entity){ |sIr?RL{C
getHibernateTemplate().save(entity); Nxk(mec"
} gKo%(6{n~
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publicvoid update(finalObject entity){ Qz,|mo+
getHibernateTemplate().update(entity); ObG=>WPJa
} <T+!V-Pj*
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publicvoid delete(finalObject entity){ `Ye8
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getHibernateTemplate().delete(entity); lpgd#vr
} M`7y>Ud
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publicObject load(finalClass entity, NHm]`R,
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finalSerializable id){ !eI2r
return getHibernateTemplate().load $f$|6jM
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(entity, id); 5Bjgr
} &GhPvrxI?
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publicObject get(finalClass entity, ,"\@fwy{
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finalSerializable id){ {X~gwoz
return getHibernateTemplate().get //f
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(entity, id); -WJ?:?'
}
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publicList findAll(finalClass entity){ +4))/`DA
return getHibernateTemplate().find("from ?r=jF)C<'
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" + entity.getName()); @?
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} ?jx1R^
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publicList findByNamedQuery(finalString Q~{H@D`<
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namedQuery){ zfA
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return getHibernateTemplate IZ/m4~
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().findByNamedQuery(namedQuery); V)(R]BK{
} dG7OqA:9
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publicList findByNamedQuery(finalString query, ?a(L.3E
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finalObject parameter){ TS2ZF{m
return getHibernateTemplate &-d&t` `
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().findByNamedQuery(query, parameter); !K
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} #X 52/8G
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publicList findByNamedQuery(finalString query, L|P5=/d
y){
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finalObject[] parameters){ nw>8GivO
return getHibernateTemplate t3(]YgF
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().findByNamedQuery(query, parameters); VXIP0p@
} 9l,a^@Y:
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publicList find(finalString query){ Bp8'pj;~
return getHibernateTemplate().find s7Ub@
5[0
O'%$
(query); q\m2EURco
} <:SZAAoIV
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publicList find(finalString query, finalObject h$4Hw+Yxs]
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parameter){ X.hm s?]
return getHibernateTemplate().find 3;S,3
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(query, parameter); bFe+m1Q_
} rM'=_nmi
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public PaginationSupport findPageByCriteria 4"gM<z
ne4Q#P
(final DetachedCriteria detachedCriteria){ 6d_'4B
return findPageByCriteria S30?VG9U0f
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); *:ZDd
} ?VP8ycm
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public PaginationSupport findPageByCriteria l
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(final DetachedCriteria detachedCriteria, finalint ^J$2?!~
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startIndex){ &*+'>UEe5
return findPageByCriteria j'A_'g'^
z^'gx@YD*v
(detachedCriteria, PaginationSupport.PAGESIZE, V5UF3'3;}
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startIndex); ;M)QwF1
} +j< p
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public PaginationSupport findPageByCriteria ,yiX# ;j
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(final DetachedCriteria detachedCriteria, finalint P-?0zF/T$
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pageSize, JpXlBEio%
finalint startIndex){ ML|FQ
return(PaginationSupport) &5yVxL:
e )d`pQ6
getHibernateTemplate().execute(new HibernateCallback(){ jYk&/@`Ly
publicObject doInHibernate 4 o Fel.o
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(Session session)throws HibernateException { E|iQc8gr&
Criteria criteria = Zy`m!]G]80
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detachedCriteria.getExecutableCriteria(session);
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int totalCount = OCe!.`
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((Integer) criteria.setProjection(Projections.rowCount oKuI0-*mR
;ub;lh 3
()).uniqueResult()).intValue(); F1*>y
criteria.setProjection nT7%j{e=L
c2l@6<Ww
(null); H?yK~bGQ
List items = $a.JSXyxL
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criteria.setFirstResult(startIndex).setMaxResults >*35C`^
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(pageSize).list(); V%rzk*LA
PaginationSupport ps = Z^3rLCa
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new PaginationSupport(items, totalCount, pageSize, ]_f_w9]
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startIndex); oB(?_No7
return ps; gb[5&>(#
} ?:Uv[|S#>
}, true); J,'M4O\S
} 0CnOL!3.I
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public List findAllByCriteria(final 9+Np4i@
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DetachedCriteria detachedCriteria){ 3dg1DR;
return(List) getHibernateTemplate ;17E(tl
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().execute(new HibernateCallback(){
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publicObject doInHibernate 8V'~UzK
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(Session session)throws HibernateException { 03$mYS_?
Criteria criteria = I fK,b*%
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detachedCriteria.getExecutableCriteria(session); (nQ^
return criteria.list(); ^9v4O UG
} .]8ZwAs=&
}, true); n1Yp1"2b[
} qU \w=
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public int getCountByCriteria(final is?{MJZ_
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DetachedCriteria detachedCriteria){ =Qy<GeY
Integer count = (Integer) \1k79 c
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getHibernateTemplate().execute(new HibernateCallback(){ /:cd\A}
publicObject doInHibernate OAgniLv
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(Session session)throws HibernateException { )HEa<P^kJl
Criteria criteria = cn3#R.G~
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detachedCriteria.getExecutableCriteria(session); 1.}d.t
return iDpSj!x/_
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criteria.setProjection(Projections.rowCount '+@=ILj>
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()).uniqueResult(); &sl0W-;0
} bTI|F]^!
}, true); esJ~;~[@(r
return count.intValue(); vx{}}/B]J
} ]}V<*f
} ncaT?~u j
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用户在web层构造查询条件detachedCriteria,和可选的 +5)nk}
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 _?nL+\'V
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PaginationSupport的实例ps。 ."g`3tVK
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ps.getItems()得到已分页好的结果集 !n`fTK<$
ps.getIndexes()得到分页索引的数组 s9mx
ps.getTotalCount()得到总结果数 -oGdk|Yn
ps.getStartIndex()当前分页索引 TP*hd
ps.getNextIndex()下一页索引 b1cy$I
ps.getPreviousIndex()上一页索引 'B|JAi?
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 10Q ]67
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 g>%o #P7
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一下代码重构了。 1C+13LE$U
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我把原本我的做法也提供出来供大家讨论吧: RHW]Z
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首先,为了实现分页查询,我封装了一个Page类: 70?\ugxA
java代码: hPkp;a #
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/*Created on 2005-4-14*/ C[cbbp
package org.flyware.util.page; `v!urE/gg%
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/** e+7"/icK
* @author Joa K-)]
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* LH.]DVj
*/ tAd%#:K
publicclass Page { !/b>sN}
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/** imply if the page has previous page */ au(D66VO
privateboolean hasPrePage; g{)dP!}
+HpA:]#Y
/** imply if the page has next page */ Vr)S{k-Q
privateboolean hasNextPage; @D[_}JE
1ba~SHi
/** the number of every page */ bSlF=jT[S
privateint everyPage; /{J4:N'B>
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/** the total page number */ C3f' {}
privateint totalPage; L[fiU0^o
!PlEO 2at
/** the number of current page */ _yx>TE2e
privateint currentPage; (S5R!lpO
NR6#g,+7
/** the begin index of the records by the current G$"h&Xy1c
&m7]v,&
query */ ?zMHP#i
privateint beginIndex; Q$W
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/** The default constructor */ %wg-=;d4
public Page(){ eKgBy8tNS0
fw~Bza\e
} Q8tL[>Xt
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/** construct the page by everyPage jOunWv|
* @param everyPage HWrO"b*tO
* */
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public Page(int everyPage){ d"mkL-
this.everyPage = everyPage; /Iy]DU8
} wssRA?9<
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/** The whole constructor */ *%NT~C
q
public Page(boolean hasPrePage, boolean hasNextPage, P )"m0Lu<
TER=*"!
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int everyPage, int totalPage, 2#]#sZmk
int currentPage, int beginIndex){ c|y(2K)o[=
this.hasPrePage = hasPrePage; Qj.#)R
this.hasNextPage = hasNextPage; t#})Awy^R
this.everyPage = everyPage; <?6|.\&
this.totalPage = totalPage; P6`u._mX
this.currentPage = currentPage; rQs)O<jl
this.beginIndex = beginIndex; [A~xy'T
} S(lO(gY
BLdvyVFx
/** &j`} vg
* @return (,Q7@s
* Returns the beginIndex. B\=8_z
*/ X1|njJGO1
publicint getBeginIndex(){ DB|Y
return beginIndex; KnQ*vM*VM
} RDi]2
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/** 5"@*?X K^
* @param beginIndex +b<FO+E_
* The beginIndex to set. ~O0 $Suv
*/ }Yzco52
publicvoid setBeginIndex(int beginIndex){ =E4LRKn
this.beginIndex = beginIndex; QzVnL U)
} , , OW
pfD c9PMj
/** VcO0sa f`
* @return ,t?B+$E
* Returns the currentPage. Tod&&T'UW
*/ 2!m/
publicint getCurrentPage(){ b\kdKVh&
return currentPage; ?m}s4a
} Q800y??&J
+>{2*\cZ5}
/** 2g-j.TM
* @param currentPage <I\/n<*
* The currentPage to set. @ $ ;q;
*/ mbTEp*H
publicvoid setCurrentPage(int currentPage){ EF[@$j
this.currentPage = currentPage; gjwn7_
} D9=KXo^
t ;;U}
/** !mJ"gg
* @return ZF9z~9
* Returns the everyPage. O|{d[eX
*/ qFCOUl
publicint getEveryPage(){ | `2RShu
return everyPage; Q:G4Z9Kt
}
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x_N'TjS^{
/** &tLgG4pd
* @param everyPage TOB-aAO
* The everyPage to set.
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*/ z,[Hli*0
publicvoid setEveryPage(int everyPage){ OUPUixz2Z
this.everyPage = everyPage; 7hD>As7`/
} TCwFPlF|
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/** r[`9uVT/
* @return *e TqVG.
* Returns the hasNextPage. {0Yf]FQb-a
*/ RNEp4x
publicboolean getHasNextPage(){ OhQgF
return hasNextPage; K( c\wr\6
} abmYA#
zx"s*:O
/** p?%y82E
* @param hasNextPage shy-Gu&
* The hasNextPage to set. .nf#c.DI
*/ q.^;!f1
publicvoid setHasNextPage(boolean hasNextPage){ In"ZIKaC
this.hasNextPage = hasNextPage; YNyk1cE
} ky,(xT4
y{B=-\O]
/** oQ/E}Zk@
* @return (&Kk7<#`
* Returns the hasPrePage. ~]|6T~+]83
*/ $Ps|HN
publicboolean getHasPrePage(){ +;(c:@>@,
return hasPrePage; %8 B}Cb&2c
} ojm @t
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/** \j}ZB<.>
* @param hasPrePage })H wh).
* The hasPrePage to set. !I{0 _b{
*/ Tt`u:ZwhF
publicvoid setHasPrePage(boolean hasPrePage){ Ws3)gvpPA
this.hasPrePage = hasPrePage; a{'vN93
} )Yh+c=6
?
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/** v|_K/|
* @return Returns the totalPage. wv>^0\o
* ]`!>6/[
*/ *2>&"B09`
publicint getTotalPage(){ Y#ap*
return totalPage; ]!W=^!
} "b~+;<}Q
jodIv=C
/** :[.vM
* @param totalPage p;`>e>$
* The totalPage to set. e-})6)XgA
*/ :;%2BSgFU
publicvoid setTotalPage(int totalPage){ {Y(zd[
this.totalPage = totalPage; '|6]_
} ANAVn@ [
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} W]$w@.oW[
*?@?f&E/
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|"q5sym8Y_
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 Ko| d+
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个PageUtil,负责对Page对象进行构造: `$Y.Y5mGtJ
java代码: '0;l]/i.
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/*Created on 2005-4-14*/ L8@f-Kk
package org.flyware.util.page; [Q~#82hBhY
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import org.apache.commons.logging.Log; EgEa1l!NSQ
import org.apache.commons.logging.LogFactory; ?d\N(s9F
C$=%!wf
/** Uk[b|<U-`d
* @author Joa Qab>|eSm
* Ot0ap$&
*/ djl*H
publicclass PageUtil { l ~"^7H?4e
.|KyNBn
privatestaticfinal Log logger = LogFactory.getLog 5+4IN5o]=
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(PageUtil.class); VcE:G#]5
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/** 3)wN))VBX
* Use the origin page to create a new page -a}Dp~j
* @param page dw>C@c#"
* @param totalRecords 4&lv6`G `
* @return x
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*/ 'T;P;:!\
publicstatic Page createPage(Page page, int H\" sgoJ
|)th1
UH
totalRecords){ _#E0g'3
return createPage(page.getEveryPage(), .&iawz
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page.getCurrentPage(), totalRecords); %bn jgy
} mkk6`,ov
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/**
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* the basic page utils not including exception wc@X.Q[
pZ{+c
handler ij`w} V
* @param everyPage QD&`^(X1p
* @param currentPage wo{gG?B
* @param totalRecords %g$o/A$
* @return page =_*Zn(>t`
*/ *!t/"b
publicstatic Page createPage(int everyPage, int T@B/xAq5!
8U"v6S~A%Q
currentPage, int totalRecords){ zV37$Hb
everyPage = getEveryPage(everyPage); 3BUSv#w{i
currentPage = getCurrentPage(currentPage); |$Sedzj'
int beginIndex = getBeginIndex(everyPage, [#vH'y
[=q1T3
currentPage); OU_gdp
int totalPage = getTotalPage(everyPage, >Eto(
y"q
2 c{34:
totalRecords); >z>!Luw
boolean hasNextPage = hasNextPage(currentPage, Af2( 5]
)F>#*P
totalPage); Y\k#*\'Y~
boolean hasPrePage = hasPrePage(currentPage); C`9+6T
n0 {i&[I~+
returnnew Page(hasPrePage, hasNextPage, G`61~F%
everyPage, totalPage, n5NsmVW \x
currentPage, 0RLg:SV
YnAm{YyI
beginIndex); x~~|.C,
} .@U@xRu7|
_C?hHWSf"
privatestaticint getEveryPage(int everyPage){ *Kgks 4
return everyPage == 0 ? 10 : everyPage; HyZqUbHa
} WX?IYQ+
}q`S$P;
privatestaticint getCurrentPage(int currentPage){ S`0(*A[W*
return currentPage == 0 ? 1 : currentPage; -;m0R
} E,U+o $
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privatestaticint getBeginIndex(int everyPage, int 'Aq{UGN
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currentPage){ P@Oo$ o
return(currentPage - 1) * everyPage; .}TZxla0Zr
} E
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privatestaticint getTotalPage(int everyPage, int w-MCZwCr)
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totalRecords){ q ^N7I@Y
int totalPage = 0; SsDmoEeB[
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if(totalRecords % everyPage == 0)
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totalPage = totalRecords / everyPage; k)=s>&hl
else H=vUYz
totalPage = totalRecords / everyPage + 1 ; Zt{[*~
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return totalPage; ,m|h<faZL
} FHg
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privatestaticboolean hasPrePage(int currentPage){ 0-Ku7<a
return currentPage == 1 ? false : true; uh>; 8
} $Sip$\+*
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privatestaticboolean hasNextPage(int currentPage, %pL''R9VF
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int totalPage){ vr6w^&[c^
return currentPage == totalPage || totalPage == 16( QR-
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0 ? false : true; By4<2u38u
} 3;{kJQ
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} (iX+{a%"
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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。 =-n}[Y}A
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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 0 /U{p,r6`
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做法如下: ?%[@Qb=2
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 4!no~ $b
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的信息,和一个结果集List: . 3T3EX|G
java代码: A$0fKko
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/*Created on 2005-6-13*/ DsCcK3 k
package com.adt.bo; je=a/Y=%U{
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import java.util.List; )1`0PJoHE
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import org.flyware.util.page.Page; `Eo.v#<
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/** kUrkG80q|
* @author Joa hT+_(>hT
*/ 56kI
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publicclass Result { Ean5b>\
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private Page page; ~dTrf>R8M
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private List content; H8}oIA"b
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/** Si;H0uP O
* The default constructor -k"/X8
*/ *#+An<iT ;
public Result(){ Ry6@VQ"NLb
super(); a~y'RyA
} ^WWQI+pk
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/** |[b{)s?x
* The constructor using fields %YqEzlzF
* z 1X` o
* @param page b,1ePS
* @param content P.9>z7l{
*/ R.yvjPwJ
public Result(Page page, List content){ ml
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this.page = page; ~q25Yx9W@
this.content = content; YNsJZnGr8#
} d<P\&!R(
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/** :&."ttf=
* @return Returns the content. %| Lfuz*
*/ FXkM#}RgNm
publicList getContent(){ Q*ft7$l&
return content; XUuN )i
} s|r3Gv|G
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/** 0oIe>r
* @return Returns the page. St*h>V6
*/ T1=fNF
public Page getPage(){ ?^\|-Gr
return page; 1#+S+g@#
} ^s"R$?;h
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/** z!9-:
* @param content E$p+}sP(C
* The content to set. >tW#/\x{
*/ 4@ai6,<
public void setContent(List content){ k@W1-D?
this.content = content; JDT`C2-Q
} j|#Bo:2km
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/** QhJiB%M
* @param page P+/e2Y
* The page to set. Mb~F%_
*/ z-)O9PV
publicvoid setPage(Page page){ l!u_"I8j5
this.page = page; zy
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} r*Ca}Z
} YNi.SXH
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2. 编写业务逻辑接口,并实现它(UserManager, o?\?@H
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UserManagerImpl) [d]9Oa4
java代码: 4'=y:v2
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/*Created on 2005-7-15*/ b d!Y\OD
package com.adt.service; `<d }V2rdz
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import net.sf.hibernate.HibernateException; U&q