Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 .bh7
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 1Nv qtVC
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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 %_5?/H@%3z
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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 gK *=T
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分页支持类: ct(euPU
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java代码: R>[G6LOG
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package com.javaeye.common.util; E`wq`g`H<
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import java.util.List; {t'SA]|g
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publicclass PaginationSupport { JkLpoe81
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publicfinalstaticint PAGESIZE = 30; e5n"(s"G*[
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privateint pageSize = PAGESIZE; FB~IO#E8W
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privateList items; ?FZ)
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privateint totalCount; 5]3Mj*u\
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privateint[] indexes = newint[0]; eM7F8j
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privateint startIndex = 0; J]NMqiq
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public PaginationSupport(List items, int z=rSb4"W
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totalCount){ P!&yYR\
setPageSize(PAGESIZE); S*ie$}ZX
setTotalCount(totalCount); 7$L*nf
setItems(items); QT"o"B
setStartIndex(0); IJZx$8&A
} cS#| _
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public PaginationSupport(List items, int
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totalCount, int startIndex){ 8feLhWg'P
setPageSize(PAGESIZE); /)Weg1b
setTotalCount(totalCount); _#<7s`i
setItems(items); (gutDUO;
setStartIndex(startIndex); (.$e@k=
} yW}x
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public PaginationSupport(List items, int HIlTt
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totalCount, int pageSize, int startIndex){ EhOB+Mc1
setPageSize(pageSize); }%,LV]rGEZ
setTotalCount(totalCount); P[ ,
setItems(items); T<0V ^B7
setStartIndex(startIndex); kh"APxQ79
} D<^K7tJui
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publicList getItems(){ #6 $WuIG
return items; 17ynFHMd,
} gYw=Z_z
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publicvoid setItems(List items){ 6s:
this.items = items; q:,ck@-4
} P`n"E8"ab<
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publicint getPageSize(){ TI^X gl~
return pageSize; 3pkx3tp{
} 2$joM`j$
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publicvoid setPageSize(int pageSize){ rWuqlx#
this.pageSize = pageSize; R+=Xr<`%U|
} l27J
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publicint getTotalCount(){ -
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return totalCount; Ec!R3+
} @.v{hkM`
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publicvoid setTotalCount(int totalCount){ #4^D'r>pJ
if(totalCount > 0){ ~H626vT37
this.totalCount = totalCount; )dRBI)P
int count = totalCount / <TEDs4
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pageSize; 8-Z|$F"
if(totalCount % pageSize > 0) 0(|36;x
count++; )KN]"<jB
indexes = newint[count]; h]^=
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for(int i = 0; i < count; i++){ t,yMO
indexes = pageSize * J/A UOInh
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i; D^H4]7wG@
} 5S%#3YHY2
}else{ }vX/55
this.totalCount = 0; n'<F'1SWv
} b5UIX Kim
} [F^j(qTR
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publicint[] getIndexes(){ I oC}0C7
return indexes; /h K/t;
} iaQ3mk#
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publicvoid setIndexes(int[] indexes){ R-BN}ZS
this.indexes = indexes; m)xz_Plc
} !;&{Q^}
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publicint getStartIndex(){ PA${<wyBR_
return startIndex; +C`zI~8
} R"{oj]d;$F
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publicvoid setStartIndex(int startIndex){ j:J7
if(totalCount <= 0) e\H1IR3
this.startIndex = 0; #j6qq3OG
elseif(startIndex >= totalCount) _n!W4zwi
this.startIndex = indexes axiP~t2
h8? E+0
[indexes.length - 1]; NGuRyZp69&
elseif(startIndex < 0) jH]?vpP
this.startIndex = 0; `&o>7a;
else{ d2<+Pp
this.startIndex = indexes h[j(@P
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[startIndex / pageSize]; Vg8c}>7
} 4mwA o
} _{0IX
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publicint getNextIndex(){ "5$2b>_UE
int nextIndex = getStartIndex() + Y-:dPc{
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pageSize; C3e0d~C
if(nextIndex >= totalCount) #w]@yL]|is
return getStartIndex(); ;Qdw$NuW
else Te&5IB-
return nextIndex; ~#9(Q
} !l#n.Fx&3
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publicint getPreviousIndex(){ ,Q>wcE6v
int previousIndex = getStartIndex() - fdzaM&
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pageSize; t,R4q*
if(previousIndex < 0) Q`[J3-Q*{
return0; CJ[^Fi?CH
else >`Zw0S
return previousIndex; ($^=f }+
} TWo.c _l
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} \kVi&X=q:
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抽象业务类 E|omC_h
java代码: =&v&qne9
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/** [[VB'Rs
* Created on 2005-7-12 6Bn%7ZBv
*/ ">"B
package com.javaeye.common.business; K6@9=_A
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import java.io.Serializable; b0lZb'
import java.util.List; C:<TJ
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import org.hibernate.Criteria; X,i^OM_
import org.hibernate.HibernateException; s
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import org.hibernate.Session; ~<Sb:Izld
import org.hibernate.criterion.DetachedCriteria; tk,Vp3p
import org.hibernate.criterion.Projections; ZH8Oidj`
import x"n)y1y
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org.springframework.orm.hibernate3.HibernateCallback; J:Ncy}AO
import s2iL5N|"Q
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org.springframework.orm.hibernate3.support.HibernateDaoS Y@R9+7!
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upport; $VyH2+ jC
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import com.javaeye.common.util.PaginationSupport; Pvu*Y0_p
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public abstract class AbstractManager extends AWn$od`#s
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HibernateDaoSupport { Ym/y2B(
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privateboolean cacheQueries = false; Z^SF $+UN
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privateString queryCacheRegion; 0dKi25J
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publicvoid setCacheQueries(boolean `u7"s'
}KCb5_MDF
cacheQueries){ sDzlNMr?P+
this.cacheQueries = cacheQueries; :Vl2\H=P
} OXCf
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publicvoid setQueryCacheRegion(String w*7BiZ{s<
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queryCacheRegion){ y(uE
this.queryCacheRegion = sJq^>"|J
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queryCacheRegion; f+iM_MI
} Dhy@!EOS
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publicvoid save(finalObject entity){ $wx)/t<
getHibernateTemplate().save(entity); iF1E 5{dH
} d0MF\yxh
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publicvoid persist(finalObject entity){ us
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getHibernateTemplate().save(entity); I? o)X!
} %qj8*1
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publicvoid update(finalObject entity){ GN%|'eU
getHibernateTemplate().update(entity); \vQjTM-7
} FG[YH5
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publicvoid delete(finalObject entity){ q" aUA_}\
getHibernateTemplate().delete(entity); bO2s'!x
} ohPCYt
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publicObject load(finalClass entity, oPPxjag\
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finalSerializable id){ =A< Fcl\Rz
return getHibernateTemplate().load gN("{j1Q
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(entity, id); FhkS"y
} 2y0J~P! I
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publicObject get(finalClass entity, !QTfQ69Y0
vm
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finalSerializable id){ bb]r
return getHibernateTemplate().get 6bXR?0$*M.
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(entity, id); 71GyMtX
} #-*#? -
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publicList findAll(finalClass entity){ ,fa'
return getHibernateTemplate().find("from 2[8C?7_K0?
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" + entity.getName()); |)vC^=N{+
} 2sryhS'(H
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publicList findByNamedQuery(finalString
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namedQuery){ L~u@n24
return getHibernateTemplate )=vQrMyB
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().findByNamedQuery(namedQuery); D%+cf
} i6@c@n
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publicList findByNamedQuery(finalString query, &=-ZNWNo
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finalObject parameter){ (WISf}[l;
return getHibernateTemplate z9B""ws
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().findByNamedQuery(query, parameter); ^-&BGQM
} PS=N]e7k'
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publicList findByNamedQuery(finalString query, /#C}1emK
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finalObject[] parameters){ Mt93YD-2+
return getHibernateTemplate :~Z-K\
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().findByNamedQuery(query, parameters); H>qw@JiO!
} 'Cv>V"X: `
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publicList find(finalString query){ BsJ
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return getHibernateTemplate().find ,3As
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(query); A./VO
} `v|w&ty*
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publicList find(finalString query, finalObject ,_N+t:*#0
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parameter){ {|E'
return getHibernateTemplate().find 7^2
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(query, parameter); 26&$vgO~:
} oE
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public PaginationSupport findPageByCriteria jgW-&nK!
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(final DetachedCriteria detachedCriteria){ `;7eu=
return findPageByCriteria Wz%b,!
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 0,z3A>C
} dx&!RK+
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public PaginationSupport findPageByCriteria 8nj^x?bn
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(final DetachedCriteria detachedCriteria, finalint :"~SKJm
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startIndex){ 4*D'zJsJ
return findPageByCriteria r+D ?_Lk
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(detachedCriteria, PaginationSupport.PAGESIZE, ]2 7
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startIndex); Y_gMoo
} @BfJb[A#
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public PaginationSupport findPageByCriteria I0qSx{K
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(final DetachedCriteria detachedCriteria, finalint F+m%PVW:
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pageSize, D"z3SLFW{
finalint startIndex){ O)jpnNz
return(PaginationSupport) R[#vFQ
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getHibernateTemplate().execute(new HibernateCallback(){ vh/&KTe?:
publicObject doInHibernate ^c-8~r|y,
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(Session session)throws HibernateException { I""zg^Rq
Criteria criteria = ,l47;@kr
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detachedCriteria.getExecutableCriteria(session); $0mR_pA\fW
int totalCount = .DX-biX,
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((Integer) criteria.setProjection(Projections.rowCount JH|]B|3
@7? O#WmL
()).uniqueResult()).intValue(); Xt.ca,`U
criteria.setProjection #hZ`r5GvTj
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(null); vH?rln
List items = j&Trvw<t
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criteria.setFirstResult(startIndex).setMaxResults #aua6V!"
z8@[]6cW
(pageSize).list(); K7-z.WTUR
PaginationSupport ps = 8)o%0#;0B
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new PaginationSupport(items, totalCount, pageSize, cp)BPg
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startIndex); 3cA'9
return ps; $VxKv7:
} GiK4LJ~cH)
}, true); E~y(@72)
} hjgB[
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public List findAllByCriteria(final ib\_MNIb
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DetachedCriteria detachedCriteria){ KPrH1 [VU
return(List) getHibernateTemplate _qO'(DKylC
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().execute(new HibernateCallback(){ qI%X/'
publicObject doInHibernate Z_h-5VU-
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(Session session)throws HibernateException { }ip3d m
Criteria criteria = 0g`$Dap
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detachedCriteria.getExecutableCriteria(session); :OFs"bC
return criteria.list(); PWBcK_4i%
} KDS}"/
}, true); j>`-BN_
} ~Jh1$O,9o
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public int getCountByCriteria(final x:6c @2
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DetachedCriteria detachedCriteria){ YvG=P<_xw
Integer count = (Integer) TYKs2+S6
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getHibernateTemplate().execute(new HibernateCallback(){ q|g>;_
publicObject doInHibernate 8CUlE-R5
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(Session session)throws HibernateException { 6E#znRi6IE
Criteria criteria = dSI<s^n
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detachedCriteria.getExecutableCriteria(session); cSTF$62E
return RG.wu6Av
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criteria.setProjection(Projections.rowCount .%EYof
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()).uniqueResult(); \2^o,1r/
} +'$5Jtz
}, true); SU5O+;{`'
return count.intValue(); X`fb\}~R(
} ka_(8
} ^D76_'{
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用户在web层构造查询条件detachedCriteria,和可选的 ek"Uq RY
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 tv_&PIu]L
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PaginationSupport的实例ps。 P~M[i9 V
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ps.getItems()得到已分页好的结果集 +#Wwah$
ps.getIndexes()得到分页索引的数组 [w90gp1O[
ps.getTotalCount()得到总结果数 v5F+@ug
ps.getStartIndex()当前分页索引 :8`~dj.
ps.getNextIndex()下一页索引 3rY\y+m
ps.getPreviousIndex()上一页索引 T&4f}g/
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 edo+ o{^
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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 k1.%ZZMM
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一下代码重构了。 f`)*bx
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我把原本我的做法也提供出来供大家讨论吧:
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首先,为了实现分页查询,我封装了一个Page类: }K5okxio
java代码: JW!.+
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/*Created on 2005-4-14*/ = N;5T
package org.flyware.util.page; R nwFxFIQ
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/** F{4v[WP)
* @author Joa $A`m8?bY
* ez5J+
*/ B Dp")[l
publicclass Page { -p?&vQDo`
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/** imply if the page has previous page */ PXyv);#Q`
privateboolean hasPrePage; Cv@)tb
/Kh,
/** imply if the page has next page */ {-lpYD^k3
privateboolean hasNextPage; kno[ !A7_6
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/** the number of every page */ O}w%$ mq
privateint everyPage; I tb_ H
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/** the total page number */ dr(-k3ex
privateint totalPage; 14"+ctq
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/** the number of current page */ i)'tt9f$
privateint currentPage; p="0Y<2l
J?dLI_{<
/** the begin index of the records by the current !Sw=ns7
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query */ v$D U
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privateint beginIndex; x5CMP%}d
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r
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{
/** The default constructor */ peF)U
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public Page(){ 1yZA_x15:
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} *:Rs\QH
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/** construct the page by everyPage q-+:1E
* @param everyPage Rpv[rvK'
* */ 0-[naGz
public Page(int everyPage){ Lg~C:BNF
this.everyPage = everyPage; 0QT:@v2R
} Fuzb4Df
\+#EO%sN1%
/** The whole constructor */ y|)VNnWM
public Page(boolean hasPrePage, boolean hasNextPage, .$H"j>
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int everyPage, int totalPage, 71y{Dwya
int currentPage, int beginIndex){ l -xc*lC
this.hasPrePage = hasPrePage; 3LT~-SvL
this.hasNextPage = hasNextPage; w|6/ i/X
this.everyPage = everyPage;
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this.totalPage = totalPage; lcm3wJ'w
this.currentPage = currentPage; E*u*LMm
this.beginIndex = beginIndex; BvsSrse
} 1f<R,>
#G.eiqh$a
/** aopZ-^
* @return #-\5O
* Returns the beginIndex. DnFzCJ
*/ 4qz+cB_
publicint getBeginIndex(){ bD0l^?Hu!
return beginIndex; rVqQo`K\
} j<P;:
s~].iQJ{B
/** *V%"q|L8
* @param beginIndex K6t"98
* The beginIndex to set. vX\9#Hj
*/ rHTZM,zM=H
publicvoid setBeginIndex(int beginIndex){ !8[T*'LJ-
this.beginIndex = beginIndex; 4`,7tj
} DtFHh/X
L7Hv)
/** v@soS1V!
* @return o0]YDX@T
* Returns the currentPage. = V2Rq(jH
*/ O-X(8<~H=
publicint getCurrentPage(){ Xg96I:r'p
return currentPage; :Y\ ~[Y
} **L&I5Hhm
pX{wEc6}
/** jwT` Z
* @param currentPage gDVsi
* The currentPage to set. .@E5dw5
*/ DPjs?M<
publicvoid setCurrentPage(int currentPage){ Lo%vG{yTr
this.currentPage = currentPage; -dixiJ=
} s`_EkFw>Gl
gns}%\,
/** Rey+3*zUb
* @return `z\hQ%1!F
* Returns the everyPage. . s9E
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*/ A{
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publicint getEveryPage(){ -n&&d8G^s
return everyPage; :31_WJ^
} wKLYyetM!
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/** J`U]Ux/L
* @param everyPage !:!(=(4$P
* The everyPage to set. \ s aV8U7B
*/ AQUAQZc
publicvoid setEveryPage(int everyPage){ B{`adq?pW
this.everyPage = everyPage; }bv+^#
} |@iM(MM[?
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/** ~tA ^[tK
* @return FC] *^B
* Returns the hasNextPage. %-blx)Pc
*/ N:)x67,
publicboolean getHasNextPage(){ EL$DvJ~
return hasNextPage; <#h,_WP*
} z3uR1vF'
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/** bO\++zOF
* @param hasNextPage ^x\VMd3*w
* The hasNextPage to set. P+o"]/7U
*/ G0UaE1n
publicvoid setHasNextPage(boolean hasNextPage){ j~k,d.17M
this.hasNextPage = hasNextPage; /e0B$UymFu
} dn#I,xa`
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/** (<eLj Q
* @return %=UD~5!G0
* Returns the hasPrePage. BA c+T
*/ 9jTBLp-i#N
publicboolean getHasPrePage(){ ->b5"{t
return hasPrePage; v`Jt+?I
} wHj1+W
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/** ._G,uP$
* @param hasPrePage -`PziGl@<
* The hasPrePage to set. H%O\4V2s
*/ ,%TBW,>
publicvoid setHasPrePage(boolean hasPrePage){ _u[tv,
this.hasPrePage = hasPrePage; 1?Y>Xz
} )XDBK*!
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/** jw:z2:0~
* @return Returns the totalPage. S[zvR9AW&
* $H@SXx
*/ &s+l/;3
publicint getTotalPage(){ ~.W]x~X$
return totalPage; r'OqG^6JFN
} SUc%dpXZa
UH!(`Z\C
/** ['IH*gi
* @param totalPage h ik.qK
* The totalPage to set. ?XHQdN3e
*/ e]RzvWq
publicvoid setTotalPage(int totalPage){ a<<4gXx
this.totalPage = totalPage; ]@#9B>v=
} |fgUW.
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} \jiE:Qt
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OT
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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 u}iuf_
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个PageUtil,负责对Page对象进行构造: 5bLNQz\WJ
java代码: 1p}H,\o
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/*Created on 2005-4-14*/ =
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package org.flyware.util.page; /Q;wz!V$
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import org.apache.commons.logging.Log; /3ohm|!rW
import org.apache.commons.logging.LogFactory; hTtn
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/** ,.<mj !YE
* @author Joa [./FzlA s
* ?@ oF@AEx=
*/ KW .4 9
publicclass PageUtil { cqG6di7#
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privatestaticfinal Log logger = LogFactory.getLog EV?}oh"x
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(PageUtil.class); O-(V`BZe
7_I83$p'
/** l8oaDL\f
* Use the origin page to create a new page [Z$H<m{c-
* @param page B7 s{yb
* @param totalRecords WQ9e~D"
* @return fQfn7FaW_\
*/ (.4lsKN<
publicstatic Page createPage(Page page, int Tvx1+0Z%z
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totalRecords){ aFTWzz
return createPage(page.getEveryPage(), Zonjk%tC
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page.getCurrentPage(), totalRecords); : "85w#r
} s)E \
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/** 296}LW
* the basic page utils not including exception sycAAmH<
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handler +u$l]~St\
* @param everyPage #LasTN9
* @param currentPage ok\-IU?
* @param totalRecords K0.aU
* @return page 8&2+=<Q~
*/ m
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publicstatic Page createPage(int everyPage, int @su<h\)
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currentPage, int totalRecords){ ` g]
everyPage = getEveryPage(everyPage); G=:/v
currentPage = getCurrentPage(currentPage); yNvAT>H
int beginIndex = getBeginIndex(everyPage, QL7b<xDQC*
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currentPage); E=8'!
int totalPage = getTotalPage(everyPage, zy,SL
|6:
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totalRecords); RDdnOzx
boolean hasNextPage = hasNextPage(currentPage, Ev7.!
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totalPage); xgk~%X%K
boolean hasPrePage = hasPrePage(currentPage); kq}byv}3I
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returnnew Page(hasPrePage, hasNextPage, Q4u.v,sE
everyPage, totalPage, ?AyxRbk
currentPage, d>p' A_
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beginIndex); aw*]b.f
} DB|1Sqjsn
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privatestaticint getEveryPage(int everyPage){ JN
wI{
return everyPage == 0 ? 10 : everyPage; kvwnqaX
} iHPsRq!
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privatestaticint getCurrentPage(int currentPage){ ^\}qq>_
return currentPage == 0 ? 1 : currentPage; H!IVbL`a{
} 9#z$GO|<
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privatestaticint getBeginIndex(int everyPage, int b? );
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currentPage){ Pxr/*X
return(currentPage - 1) * everyPage; Y9^l|,bm5
} $?56 i4
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privatestaticint getTotalPage(int everyPage, int *V2;ds.~
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totalRecords){ \GL] I.
int totalPage = 0; Jpapl%7v
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if(totalRecords % everyPage == 0) Hhknjx
totalPage = totalRecords / everyPage; A)U"F&tvm
else
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totalPage = totalRecords / everyPage + 1 ; lx|Aw@C3~
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return totalPage; [D~]
} nCq'=L,m
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privatestaticboolean hasPrePage(int currentPage){ -qP)L;n
return currentPage == 1 ? false : true; <e UsMo<
} MH.+pqIv^
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privatestaticboolean hasNextPage(int currentPage, j-K[]$
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int totalPage){ :+"4_f0
return currentPage == totalPage || totalPage == MqZ"Js
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0 ? false : true; U6&`s%mIa
} ,iyy2
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} :M"+
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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。 %E_Y4Oe1
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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 5=?P6I_$G
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做法如下: 5k0iVpjQ
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 xrg"/?84
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的信息,和一个结果集List: AY52j
java代码: IS]A<}j/-
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/*Created on 2005-6-13*/ '/I`dj
package com.adt.bo; Wr[LC&
x Q"uC!Gu4
import java.util.List; q1VKoKb6\:
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import org.flyware.util.page.Page; GKoYT{6
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/** 'UX^]
* @author Joa eX$KH;M
*/ toY_1
publicclass Result { X;!*D
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private Page page; ZjxF@`H
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private List content; 5ngs1ZF@
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/** AZ!/{1 Az
* The default constructor AW r2Bv
*/ |5vJ:'` I
public Result(){ hrKeOwKHU
super(); 8]#FvgX
} ('7?"npd
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/** 5, ;\zSz
* The constructor using fields u{4P)DIQ
* +'m9b7+v
* @param page zLl-{Kk
* @param content }5fd:B m;
*/ f6I)c$]Q
public Result(Page page, List content){ 3Ws (],Q
this.page = page; ~u*4k:2H
this.content = content; [k
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} 8U@f/P
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/** RFbf2s\t
* @return Returns the content. ;}Jv4Z
*/ {gzQ/|}#z-
publicList getContent(){ CG%bZco((
return content; mPA)G,^
} GSRf/::I}4
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/** q;9X8 _
* @return Returns the page. p.:|Z-W$
*/ RZxh"lIo
public Page getPage(){ a?W5~?\9
return page; eztK`_n
} QuS=^,]
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/** {e&fB