Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 -4;$NiB?
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 3FglzJ
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 ~WW!P_wI,
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 \cr)O^&
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分页支持类: )8JfBzR
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java代码: |uIgZ|7[
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package com.javaeye.common.util; EK%J%NY
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import java.util.List; 3nbTK3,
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publicclass PaginationSupport { [.Y]f.D
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publicfinalstaticint PAGESIZE = 30; JYK4/gJ
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privateint pageSize = PAGESIZE; @UK%l
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privateList items; 8o SL3
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privateint totalCount; 1G}\IK1+
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privateint[] indexes = newint[0]; kZK1{
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privateint startIndex = 0; `gSJEq
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public PaginationSupport(List items, int u$Wv*;TT%
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totalCount){ :5-t$^R
setPageSize(PAGESIZE); ;39~G T
setTotalCount(totalCount); +UX~TT:
setItems(items); Htm;N2$d
setStartIndex(0); qCI0[U@
} 1]wo
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public PaginationSupport(List items, int 1Xkl.FcFw
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totalCount, int startIndex){ 5M?
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setPageSize(PAGESIZE); Ge=|RAw3
setTotalCount(totalCount); )~{8C:
setItems(items); 7csMk5NU'<
setStartIndex(startIndex); er0y~
} 9&"wfN N
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public PaginationSupport(List items, int iI$;%uY3g
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totalCount, int pageSize, int startIndex){ \GdsQAF"
setPageSize(pageSize); w?JM;'<AYQ
setTotalCount(totalCount); 87-z=>IU
setItems(items); ] ]lN[J
setStartIndex(startIndex); l3Wh&*0
} *s%M!YM
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publicList getItems(){ 9zNMv-
return items; Z&6*8#wn
} 8FJPw"9
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publicvoid setItems(List items){ 1#lH5|XQ
this.items = items; "3$P<Q\;l;
} q!as~{!
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publicint getPageSize(){ +EvY-mwfQ
return pageSize; -1%AM40j
} hr?0RPp}
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publicvoid setPageSize(int pageSize){ &9khIJIn
this.pageSize = pageSize; )5ev4Qf
} l~n=_R3
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publicint getTotalCount(){ 2Xqa?ay0>
return totalCount; 3RP\w~?
} IQyw>_~]
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publicvoid setTotalCount(int totalCount){ C4|H5H
if(totalCount > 0){ yaK4% k
this.totalCount = totalCount; ,D93A
int count = totalCount / ?#|in}
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pageSize; %TDY &@i=
if(totalCount % pageSize > 0) bb!cZ>Z
count++; Vy+kq_9
indexes = newint[count]; }_h2:^n
for(int i = 0; i < count; i++){ "
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indexes = pageSize * roNs~]6
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} "vo
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}else{ p sAr>:\3
this.totalCount = 0; _YA;Nd#%k
} Bi`m +ob
} v4W<_
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publicint[] getIndexes(){ +|.6xC7U
return indexes; a9p6[qOcd
} l*|m(7s
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publicvoid setIndexes(int[] indexes){ s>a(#6Q
this.indexes = indexes; 0:zDt~Ju
} SV i{B*
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publicint getStartIndex(){ 8RJa;JsH
return startIndex; |K'7BK_^J
} U>a~V"5,u
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publicvoid setStartIndex(int startIndex){ PaBqv]
if(totalCount <= 0) dk@iAL*v
this.startIndex = 0; Rqun}v}
elseif(startIndex >= totalCount) s AlOX`t
this.startIndex = indexes \)+s)&JLb
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[indexes.length - 1]; zF_aJ+i:~
elseif(startIndex < 0) 86ml.VOR
this.startIndex = 0; )"&\S6*!
else{ .!Q?TSQ+{!
this.startIndex = indexes "/zDcZbL;
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[startIndex / pageSize]; 4 moVS1
} e%v0EJ},
} FS6I?q#tQ
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publicint getNextIndex(){ l1D"*J 2`
int nextIndex = getStartIndex() + DTM
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pageSize; \:_!!
if(nextIndex >= totalCount) m*\XH
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return getStartIndex(); y*5$B.u`.
else jrm
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return nextIndex; \j~LxV
} I.'sK9\Zp
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publicint getPreviousIndex(){ br7_P1ep
int previousIndex = getStartIndex() - <dX7{="&
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pageSize; zXT[}J VV
if(previousIndex < 0) XFcIBWS
return0; k+As#7V
else tzSg`7H!
return previousIndex; -%g{{'9B
} & <Jvaf_=
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} #{Gojg`5O
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抽象业务类 = ms
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java代码:
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/** q)KLf\
* Created on 2005-7-12 jthGNVZ
*/ 5ofsJ!b'
package com.javaeye.common.business; ~riV9_-
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import java.io.Serializable; P1}Fn:Xe%7
import java.util.List; Vv5#{+eT;
*XSHzoT*
import org.hibernate.Criteria; G~|Z(}H
import org.hibernate.HibernateException; D4W^{/S
import org.hibernate.Session; r d4\N2- 6
import org.hibernate.criterion.DetachedCriteria; @Z%I g
import org.hibernate.criterion.Projections; I\oI"\}U
import OA\
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org.springframework.orm.hibernate3.HibernateCallback; o&vODs
import eWwI@ASaA
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org.springframework.orm.hibernate3.support.HibernateDaoS *kWrF* )J
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upport; *Wmn!{\g
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import com.javaeye.common.util.PaginationSupport; UXN!iU)
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public abstract class AbstractManager extends C`>|D [
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HibernateDaoSupport { )4/227b/(
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privateboolean cacheQueries = false; ZsikI@?
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privateString queryCacheRegion; 4Js9"<w
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publicvoid setCacheQueries(boolean #.z`clK#
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cacheQueries){ -jOCzp
this.cacheQueries = cacheQueries; >"q~9b
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} |XdkJv]
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publicvoid setQueryCacheRegion(String v3{[rK}
h(VF
queryCacheRegion){ p 6FPdt)
this.queryCacheRegion = W2\Q-4D
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queryCacheRegion; $VLCD
} LVX01ox$
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publicvoid save(finalObject entity){ T2V#
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getHibernateTemplate().save(entity); iSz?V$}?
} 'aoHNZfxw
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publicvoid persist(finalObject entity){ EO[UezuU
getHibernateTemplate().save(entity); ntT~_Ba8;u
} gAWrn^2L5
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publicvoid update(finalObject entity){ 7JI&tlR4\c
getHibernateTemplate().update(entity); BXf.^s{H
} ^7l^/GSO
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publicvoid delete(finalObject entity){ "Lp"o
getHibernateTemplate().delete(entity); =Nj58 l
} 8+7=yN(
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publicObject load(finalClass entity, H _%yh,L
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finalSerializable id){ ?NL>xMA
return getHibernateTemplate().load ix=H=U]Q{
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(entity, id); ORo +=2
} 5wws8w
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publicObject get(finalClass entity,
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finalSerializable id){ ^Q\O8f[u
return getHibernateTemplate().get "?~u*5
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(entity, id); *8*E\nZx!
} K&WNtk3hT
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publicList findAll(finalClass entity){ JyBsOC3
return getHibernateTemplate().find("from S2jO
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" + entity.getName()); '0!IF&p'
} `ju r`^S|
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publicList findByNamedQuery(finalString #!%\97ZR
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namedQuery){ @?GOOD_i
return getHibernateTemplate '5mzlR
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().findByNamedQuery(namedQuery); ;S FmbZ%~
} G1d!a6>
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publicList findByNamedQuery(finalString query, ]eJjffx
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finalObject parameter){ vh~:{akR
return getHibernateTemplate jaj."v
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().findByNamedQuery(query, parameter); }Dig'vpMx
} btC.EmX
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publicList findByNamedQuery(finalString query, myj^c>1Iz
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finalObject[] parameters){ U-$ B"w &
return getHibernateTemplate N2"4dVV;
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().findByNamedQuery(query, parameters); bD[6)
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} h%Nbx:vKk
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publicList find(finalString query){ ( /cW
return getHibernateTemplate().find @' Er&[P
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(query); ,'CDKzY
} =~&Fq$$
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publicList find(finalString query, finalObject J jCzCA:K_
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parameter){ $h Isab_
return getHibernateTemplate().find [1Dg_>lz
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(query, parameter); h<wF;g,
} XB &-k<C
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public PaginationSupport findPageByCriteria T~k5` ~\(
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(final DetachedCriteria detachedCriteria){ Xf.w(-
return findPageByCriteria KB,!s7A
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); iz`u@QKc%
} /:a~;i
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public PaginationSupport findPageByCriteria VY'#>k}}
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(final DetachedCriteria detachedCriteria, finalint R {r0dK"_
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startIndex){ `A\
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return findPageByCriteria #]ii/Et#x
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(detachedCriteria, PaginationSupport.PAGESIZE, wovWEtVBU
.Lrdw3(
startIndex); /Xi:k
} Kfc(GL?
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public PaginationSupport findPageByCriteria ku*|?uF
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(final DetachedCriteria detachedCriteria, finalint .cA[b
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pageSize, +:2(xgOP.V
finalint startIndex){ _Gy*" ;E
return(PaginationSupport) 0\AYUa?RM
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getHibernateTemplate().execute(new HibernateCallback(){ ;o\0:fzr
publicObject doInHibernate @ :i>q$aF
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(Session session)throws HibernateException { t-SGG{
Criteria criteria = +fzZ\
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detachedCriteria.getExecutableCriteria(session); P%smX`v
int totalCount = !+cRtCaA::
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((Integer) criteria.setProjection(Projections.rowCount d}b#"A
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()).uniqueResult()).intValue(); M`umfw T
criteria.setProjection H7)(<6b,z
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(null); uJG^>B?`b
List items = LX
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criteria.setFirstResult(startIndex).setMaxResults GZ@!jF>!u
pTmG\wA~$
(pageSize).list(); +D1;_DU
PaginationSupport ps = +bd/*^
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new PaginationSupport(items, totalCount, pageSize, 4;|&}Ij
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startIndex); ltHC+8aZ
return ps; udg;jR-^
} :$[m[y7i
}, true); SsafRK$
} <acAc2
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public List findAllByCriteria(final z@VY s
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DetachedCriteria detachedCriteria){ K^H=E
return(List) getHibernateTemplate +98~OInySZ
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().execute(new HibernateCallback(){ hdN3r{
publicObject doInHibernate f&^K>Jt1@#
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(Session session)throws HibernateException { $|z8WCJ
Criteria criteria = =bf-+gZD
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detachedCriteria.getExecutableCriteria(session); g<KBsz!{
return criteria.list(); Czb@:l%sc
} P 2;j>=W
}, true); g;=jZ
} _}`iLA!$I
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public int getCountByCriteria(final ?{cF'RB.
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DetachedCriteria detachedCriteria){ `-Gs*#(/
Integer count = (Integer) Tb}`]Y`X
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getHibernateTemplate().execute(new HibernateCallback(){ )R{4"&&2
publicObject doInHibernate s<z{ (a
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(Session session)throws HibernateException { if:2sS9r
Criteria criteria = @<},- u
ksm=<I"C
detachedCriteria.getExecutableCriteria(session); EEn}Gw
return ~|Gtm[9Ru
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criteria.setProjection(Projections.rowCount j4H,*fc
)F]E[sga
()).uniqueResult(); |,t#Au}61
} 5`6@CRef
}, true); 2#6yO`?uo
return count.intValue(); b)$<aFl
} E[2c`XFd8
} Y4!v1
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用户在web层构造查询条件detachedCriteria,和可选的 hRxR2
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 C#>c(-p>RC
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PaginationSupport的实例ps。 N}VKH5U|
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ps.getItems()得到已分页好的结果集 RH6qi{)i!
ps.getIndexes()得到分页索引的数组 98Pt&C? -B
ps.getTotalCount()得到总结果数 a,M7Bbx
ps.getStartIndex()当前分页索引 TS$ 2K
ps.getNextIndex()下一页索引 Q>JJI:uC4
ps.getPreviousIndex()上一页索引 :%xiH%C>
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Z!~~6Sq
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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 ga6M8eOI
~e ]83?
一下代码重构了。 m}Kn!21
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我把原本我的做法也提供出来供大家讨论吧: !95ZK.UT
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首先,为了实现分页查询,我封装了一个Page类: ~WehG<p v[
java代码: vkASp&a
HeNg<5v%Y
1 nX/5z_U
/*Created on 2005-4-14*/ vitmG'|WG
package org.flyware.util.page; ,>`wz^z
D$I7Gz,w{
/** QP >P
* @author Joa ~H7m7
* _rY,=h{+
*/ :JxShF:M
publicclass Page { m:)v>v u
DZilK:
/** imply if the page has previous page */ "S_t%m&R
privateboolean hasPrePage; ygWo9?
oOmPbAY
/** imply if the page has next page */ qOV#$dkY
privateboolean hasNextPage; ,N?~je.
#fRhG^QKp
/** the number of every page */ 4nXS}bW f
privateint everyPage; 3!,XR\`[
}R;.~F
/** the total page number */ 3/@7$nV
privateint totalPage; y5RcJM
Tc T%[h!
/** the number of current page */ 5|9,S
privateint currentPage; *y='0)[BD
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/** the begin index of the records by the current O!\P]W4r$
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query */ tl
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privateint beginIndex; KArR.o }
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5 nkx8JJ
/** The default constructor */ .]k+hc`
public Page(){ i"r&CS)sT
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} |Eu_K`
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/** construct the page by everyPage /![S 3Ol
* @param everyPage *rXESw]BR
* */ R/Mwq#xUb
public Page(int everyPage){ ?nn`ud?f
this.everyPage = everyPage; o6'I%Gs
} h*Rh:yCR>
*}-X
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/** The whole constructor */ I_6?Q^_uZ
public Page(boolean hasPrePage, boolean hasNextPage, <_dyUiT$J
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int everyPage, int totalPage, hJ (Q^Z
int currentPage, int beginIndex){ 5IOOV Yl
this.hasPrePage = hasPrePage; `{gkL-
this.hasNextPage = hasNextPage; lQ<2Vw#Yl
this.everyPage = everyPage; C5CUMYU
this.totalPage = totalPage; IgI*mDS&b
this.currentPage = currentPage; >8"oO[U5>
this.beginIndex = beginIndex; /XeDN-{
} 0k@4;BY u
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/** V}. uF,>V
* @return d(3F:dbk
* Returns the beginIndex. AE={P*g
*/ w4Qqo(
publicint getBeginIndex(){ j&6,%s-M`a
return beginIndex; GvF8S MO[x
} '_lyoVP
zH0%;
o}
/** [ >O4hifq
* @param beginIndex 9z$]hl
* The beginIndex to set. WS/^WxRY
*/ n#uH^@#0
publicvoid setBeginIndex(int beginIndex){ +iz5%Qe<f
this.beginIndex = beginIndex; 5Q#;4
} Kfa7}f_
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/** y>Zvos e
* @return e6z;;C@'G
* Returns the currentPage. lM86 *g 'l
*/ K_{f6c<
publicint getCurrentPage(){ 4v_?i@,L
return currentPage; m2E$[g
} F l83
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/** 7g[m,48{
* @param currentPage orVsMT[A
* The currentPage to set. b'Pq[ )
*/ 4.I6%Bq$
publicvoid setCurrentPage(int currentPage){ q#:,6HDd
this.currentPage = currentPage; ZF"f.aV8)
} O$k;p<?M
7!+kyA\}r^
/** nd3=\.(P
* @return g0v},n
* Returns the everyPage. VUC
*/
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publicint getEveryPage(){ >J_{mU
return everyPage; O#
.^}
} '%_1eaH
Q/m))!ikMt
/** 7}OzTup
* @param everyPage Fvf308[
* The everyPage to set. S~d_SU~>`
*/ IT!
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publicvoid setEveryPage(int everyPage){ &I
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this.everyPage = everyPage; 1 mhX3
} (Z"QHfO'
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/** SweaERl
* @return LTj;e[
* Returns the hasNextPage. fu?5gzT+b
*/ nF~</>
publicboolean getHasNextPage(){ ,Xs%Cg_Ig
return hasNextPage; vo)pT
} 4!p~Mr[E
7Fw`s@/%
/** u*B.<GmN
* @param hasNextPage .j:.?v
* The hasNextPage to set. fzO4S^mTo8
*/ 8J{I6nPF
publicvoid setHasNextPage(boolean hasNextPage){ 8>S"aHt 7
this.hasNextPage = hasNextPage; L&=j O0_
} A`v (hBM
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/** F]]np&UV.
* @return gYVk5d|8@4
* Returns the hasPrePage. GE]fBg
*/ #/$}zl
publicboolean getHasPrePage(){ ["- pylhK
return hasPrePage; ;j])h!8X
} k@JDG]R<{
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/** &,4]XT
* @param hasPrePage ^wPKqu)^
* The hasPrePage to set. @P#uH5U
*/ |7n&I`#
publicvoid setHasPrePage(boolean hasPrePage){ .yE!,^j.gB
this.hasPrePage = hasPrePage; AN7WMX
} OLJb8kO
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/** sUN>uroi !
* @return Returns the totalPage. >8Wvz.Nq/
* "'h?O*V]u{
*/ $gT+Ue|7
publicint getTotalPage(){ jXvGL
return totalPage; 3p{N7/z(
} )k01K,%#)
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/** <9 lZ%j;
* @param totalPage drP2%u
* The totalPage to set. j89|hG)2
*/ kKVd4B[#*
publicvoid setTotalPage(int totalPage){ %[\:
8
this.totalPage = totalPage; s:lar4>kM
} ^0"NcOzzxl
zqfv|3-!}
} DrLNY"Zq
}1]/dCv
:bI4HXT3
v39`ct= e
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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 tt%Zwf
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个PageUtil,负责对Page对象进行构造: \s?OvqI:
java代码: V2sWcV?
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/*Created on 2005-4-14*/ `l@[8H%aw
package org.flyware.util.page; "r @RDw
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import org.apache.commons.logging.Log; ;l>
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import org.apache.commons.logging.LogFactory; F+PIZ%
hLFf
/** GHj1G,L@\
* @author Joa *@o@>
* 7Ipt~K}
*/ E*ybf'
publicclass PageUtil { vpXC5|9U
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privatestaticfinal Log logger = LogFactory.getLog r@FdxsCnGM
+qq,;npi
(PageUtil.class); 9 tkj:8_
&?>h#H222
/** K];nM}<
* Use the origin page to create a new page O-Hu:KuIf
* @param page I\DmVc\l
* @param totalRecords T:o!H
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* @return :zfnp,Gv
*/ v#&r3ZW0
publicstatic Page createPage(Page page, int 0fA42*s;
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totalRecords){ ?g|K"P<1
return createPage(page.getEveryPage(), v{`Z
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page.getCurrentPage(), totalRecords); UgDai?b1
} -q' n p0H
DfwxPt#
/** (1H_V(
* the basic page utils not including exception 9\i;zpN\
q"ba~@<BEl
handler KK4>8zGR
* @param everyPage *6 -;iT8
* @param currentPage 6la# 0U23
* @param totalRecords ?xh_qy;
* @return page +*'
*/ J XKps#,(#
publicstatic Page createPage(int everyPage, int _?>!Bz
m
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currentPage, int totalRecords){ ms'&.u&<
everyPage = getEveryPage(everyPage); =o\:@I[
currentPage = getCurrentPage(currentPage); u{0+w\xH\
int beginIndex = getBeginIndex(everyPage, E{gu39 D
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currentPage); J0zudbP
int totalPage = getTotalPage(everyPage, o_&.R
|t CD@M
totalRecords); MV6%~T
boolean hasNextPage = hasNextPage(currentPage, Ag}V>i'
qd{o64;|
totalPage); pcXY6[#N
boolean hasPrePage = hasPrePage(currentPage); HX\@Qws
;wND?:
returnnew Page(hasPrePage, hasNextPage, >"?HbR9
everyPage, totalPage, $_ub.g|
currentPage, '7o'u]
#@H{Ypn`
beginIndex); %Y%+K5;AZ
} }u
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privatestaticint getEveryPage(int everyPage){ C>7Mx{ !H
return everyPage == 0 ? 10 : everyPage; fHvQ 9*T
} f/Km$#xOr
jENarB^As
privatestaticint getCurrentPage(int currentPage){ cd{3JGgB
return currentPage == 0 ? 1 : currentPage; wpu]{~Y
} 2!>phE
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privatestaticint getBeginIndex(int everyPage, int Gp9>R~$
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currentPage){ G&:[G>iSm^
return(currentPage - 1) * everyPage; }hyK/QUCoN
} ac>}$Uw)
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privatestaticint getTotalPage(int everyPage, int 8~RUYsg
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totalRecords){ +JZ<9,4
int totalPage = 0; G?\o_)IJ
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if(totalRecords % everyPage == 0) $>v^%E;Y4
totalPage = totalRecords / everyPage; q_>DX,A
else FW#Lf]FJ
totalPage = totalRecords / everyPage + 1 ; -aG( Yx
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return totalPage; Ek_k_!
} X
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privatestaticboolean hasPrePage(int currentPage){ /'
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return currentPage == 1 ? false : true; [?Y u3E\
} asP>(Li
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privatestaticboolean hasNextPage(int currentPage, ]n?a h
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int totalPage){ S$W
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return currentPage == totalPage || totalPage == RL~|Kr<7J
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0 ? false : true; [UNfft=K3P
} hDmtBdE
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} pW8pp?
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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。 ^*C6]*C}te
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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 "V~U{(Z
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做法如下: xp/u, q
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 \s&w0V`Y
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的信息,和一个结果集List: RTA9CR)JP4
java代码: H;*:XLPF
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/*Created on 2005-6-13*/ [=e61Z
package com.adt.bo; [#j|TBMHM
ig; ~
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import java.util.List; IK{0Y#c
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import org.flyware.util.page.Page; i3: sV 5
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/** GY,@jp|R
* @author Joa 0VoC|,$U
*/ ZT8. r0
publicclass Result { y>2v 9;Qp
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private Page page; C,]Q/6'>
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private List content; N<Bi.\XC
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/** i/O!bq[o
* The default constructor po=*%Zs*T
*/ >~BU<#
public Result(){ (n"M)
super(); ,~K_rNNZ
} ?jw)%{iKYV
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/** A40 -])'!
* The constructor using fields PG<N\
* 7 bsW7;C
* @param page =6
* @param content z &<Rx[
*/ P_-zkw
public Result(Page page, List content){ +hjc~|RK
this.page = page; V$q%=Sip
this.content = content; 2_r}4)z
} >ID 3oi
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/** UeHS4cW
* @return Returns the content. lBQ|=
*/ rUlpo|B
publicList getContent(){ 'U1r}.+b>
return content; "j$}'uK<
} [FiXsYb.8
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/** /unOZVr(
* @return Returns the page. Q2rZMK
*/ m
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public Page getPage(){ )QBsyN<x6
return page; `R:<(:
} &~E=T3
J\;~(:
~
/** ^D.B^BR
* @param content !+>yCy$~_
* The content to set. -vjjcyTt
*/ JAB]kNvI
public void setContent(List content){ }=f}@JlFB
this.content = content; <V6#)^Or
} JH)&Ca>S
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/** E&&