Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 &? z6f9*$
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ZE4xF8
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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 qV7nF
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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 yGX"1Fb?;x
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分页支持类: HiPd|D
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java代码: sFa5#w*>
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package com.javaeye.common.util; W>T6Wlxu`6
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import java.util.List; h?+bW'm
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publicclass PaginationSupport { 0PT\/imgN
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publicfinalstaticint PAGESIZE = 30; )Y
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privateint pageSize = PAGESIZE; OM 4,Sevk
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privateList items; J)"g`)\2 +
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privateint totalCount; \&.]!!Q
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privateint[] indexes = newint[0]; 3PgiV%]
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privateint startIndex = 0; cgF?[Z+x
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public PaginationSupport(List items, int w;4FN'
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totalCount){ z-;2)RkV2
setPageSize(PAGESIZE); :$?^ID
setTotalCount(totalCount); K3On8
setItems(items); Yk!TQY4
setStartIndex(0); }J-+^
} /`vn/X^?^
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public PaginationSupport(List items, int E|> oseR
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totalCount, int startIndex){ o:8*WCiqrN
setPageSize(PAGESIZE); "l.1 UB&
setTotalCount(totalCount); LH]<+Zren
setItems(items); fBRU4q=^T
setStartIndex(startIndex); C=uYX"
} [K4wd%+
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public PaginationSupport(List items, int 5}"@$.{i
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totalCount, int pageSize, int startIndex){ u[;,~eB%w
setPageSize(pageSize); Od5I:p]N
setTotalCount(totalCount); GfMCHs
setItems(items); D`C#O
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setStartIndex(startIndex); {
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} bJ#]Xm(]D
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publicList getItems(){ UoSzxL
return items; M)v4>Rw+
} DpZO$5.Ec+
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publicvoid setItems(List items){ F:B8J4/
this.items = items; D8S3YdJ
} 5B76D12
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publicint getPageSize(){ xG|T_|?
return pageSize; U1!#TD)@
} ejjL>'G/|%
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publicvoid setPageSize(int pageSize){ . \6q\7Ej
this.pageSize = pageSize; rrL
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} ~ WO
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publicint getTotalCount(){ {BS}9jZx
return totalCount; 7u|X
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} |0Y:
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publicvoid setTotalCount(int totalCount){ m:
if(totalCount > 0){ 0!fT:Ra
this.totalCount = totalCount; XHER [8l
int count = totalCount / #FNSE*Y
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pageSize; AIU=56+I\
if(totalCount % pageSize > 0) 9>I&Z8J$M
count++; :Ou[LF.O
indexes = newint[count]; Q 2mTu[tx
for(int i = 0; i < count; i++){ rTmVHt
indexes = pageSize * Xvr7qowL
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i; mN&B|KWU
} 5z~O3QX
}else{ r\."=l
this.totalCount = 0; ]o<&Q52 |
} hzcSKRm
} ;rqW?':(i
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publicint[] getIndexes(){ p`I[3/$3
return indexes; n)t'?7
} Zk:_Yiki&
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publicvoid setIndexes(int[] indexes){ \0,8?S
this.indexes = indexes; L4t(Y7
} &ra2(S45
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publicint getStartIndex(){ gCL?{oVU
return startIndex; 3o^~6A
} "969F(S$
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publicvoid setStartIndex(int startIndex){ h2P&<gg qX
if(totalCount <= 0) s/\<;g:u^
this.startIndex = 0; @=NTr
elseif(startIndex >= totalCount) 9cXL4
this.startIndex = indexes I1 +A$<Fa
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[indexes.length - 1]; ,~G:>q$ad
elseif(startIndex < 0) H.]p\UY9
this.startIndex = 0; k!0vpps
else{ l[Ko>
this.startIndex = indexes !IC@^kkh{
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[startIndex / pageSize]; J;S Z"I'
} r*kz`cJ
} f#&@Vl(i&
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publicint getNextIndex(){ b>@fHmpwD
int nextIndex = getStartIndex() + sB=s .`9
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pageSize; (vPE?^}b
if(nextIndex >= totalCount) $VJE&b
return getStartIndex(); TeHxqWx
else ^0(`:*
return nextIndex; gg&Dej2{
} +%H2;8{F
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publicint getPreviousIndex(){ , GMuq_H
int previousIndex = getStartIndex() - V>"NVRY
hY/i)T{
pageSize; 0IxHB|^$
if(previousIndex < 0) SD .c9
return0; \79aG3MyK
else ',s{N9
return previousIndex; @#::C@V]
} uiq;{!dop
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} oRHWb_$"
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抽象业务类 tRXR/;3O
java代码: 6D29s]h2
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/** aq$adPtu
* Created on 2005-7-12 .xg, j{%(
*/ 9m}c2:p
package com.javaeye.common.business; D1~3 3;
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import java.io.Serializable; 5uD'Kd$H
import java.util.List; F2CoXe7
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import org.hibernate.Criteria; q6zKyOE
import org.hibernate.HibernateException; ?OdJt
import org.hibernate.Session; -MItZ
import org.hibernate.criterion.DetachedCriteria; 22"/|S
import org.hibernate.criterion.Projections; `YPNVm<3)
import
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org.springframework.orm.hibernate3.HibernateCallback; zP#%ya:I
import KHt.g`1:R
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org.springframework.orm.hibernate3.support.HibernateDaoS Xw<N nvz6
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upport; :EZ"D#>y~
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import com.javaeye.common.util.PaginationSupport; EFS2 zU
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public abstract class AbstractManager extends l} UOg
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HibernateDaoSupport { "jEf$]
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privateboolean cacheQueries = false; tQrkRg(E:
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privateString queryCacheRegion; Hm55R
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publicvoid setCacheQueries(boolean q$6Tb
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cacheQueries){ q/HwcX+[b
this.cacheQueries = cacheQueries; 3erGTa[|q
} &
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publicvoid setQueryCacheRegion(String ESt@%7.F
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queryCacheRegion){ 1C'_I
this.queryCacheRegion = G@Y!*ZH*f
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queryCacheRegion; (5(TbyWwD
} P\R#!+FgW8
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publicvoid save(finalObject entity){
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getHibernateTemplate().save(entity); - r!sY+Z>
} R:t>PFwo
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publicvoid persist(finalObject entity){ ~'<ca<Go|
getHibernateTemplate().save(entity); l4+Bs!i`
} .V Cfh+*J#
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publicvoid update(finalObject entity){ yMoV|U6
getHibernateTemplate().update(entity); s35`{PR
} ,_(AiQK
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publicvoid delete(finalObject entity){ c/Ykk7T9--
getHibernateTemplate().delete(entity); -]K9sy)I
} vRQ7=N{3
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publicObject load(finalClass entity, d^sm;f
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finalSerializable id){ gx',~
return getHibernateTemplate().load @jxAU7!
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(entity, id); 0;V "64U
} @z-%:J/$
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publicObject get(finalClass entity, v{[:7]b_=
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finalSerializable id){ /)<x<7FKW
return getHibernateTemplate().get UTLuzm
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(entity, id); ._i|+[
} 7B)m/%>3s
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publicList findAll(finalClass entity){ 4Nun-(q
return getHibernateTemplate().find("from <Cbi5DtR
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" + entity.getName()); L]kd.JJvy
} !w;oVPNg
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publicList findByNamedQuery(finalString ' %&gER
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namedQuery){ R ~ZcTY[8
return getHibernateTemplate .V
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().findByNamedQuery(namedQuery);
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} /2.}m`5
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publicList findByNamedQuery(finalString query, VchI0KL?
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finalObject parameter){ !y\r.fm!A
return getHibernateTemplate 8v }B-cS
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().findByNamedQuery(query, parameter); K'_qi8Z
} YWFq&II|Z
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publicList findByNamedQuery(finalString query, ?:$\
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finalObject[] parameters){ 4OaU1Y[
return getHibernateTemplate &"r /&7:
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().findByNamedQuery(query, parameters); ?Gl]O3@3
} )GYnQoV4
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publicList find(finalString query){ 0,/I2!dF?
return getHibernateTemplate().find hm*cGYV/
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(query); SF=TG84<
} g\% Z+Dc
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publicList find(finalString query, finalObject ,g pZz$Ef(
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parameter){ PU,%Y_xR
return getHibernateTemplate().find jF}-dfe
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(query, parameter); =%B5TBG
} e }Mf
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public PaginationSupport findPageByCriteria fX.1=BjXi
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(final DetachedCriteria detachedCriteria){ 5a-x$Qb9
return findPageByCriteria s&hr$`V4
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); g#MLA5%=u
} L#",.x
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public PaginationSupport findPageByCriteria D4b-Y[/"
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(final DetachedCriteria detachedCriteria, finalint WfD fj
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startIndex){ R_O=WmD
return findPageByCriteria ;=7K*npT
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(detachedCriteria, PaginationSupport.PAGESIZE, QtwQVOK
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startIndex); b[GhI+_
} J#48c'
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public PaginationSupport findPageByCriteria j*5IRzK1%0
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(final DetachedCriteria detachedCriteria, finalint HhL;64OYa
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pageSize, 4EHrd;|
finalint startIndex){ x9,jXd
return(PaginationSupport) V^,eW!
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getHibernateTemplate().execute(new HibernateCallback(){ ~ney~Pz_
publicObject doInHibernate Bb:C^CHIQm
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(Session session)throws HibernateException { WFiX=@SS
Criteria criteria = G[\TbPh
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detachedCriteria.getExecutableCriteria(session); D3yTN"
int totalCount = Jup)A`64
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((Integer) criteria.setProjection(Projections.rowCount b?l>vUgAg
qx'0(q2Ii(
()).uniqueResult()).intValue(); B
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criteria.setProjection a8f#q]TyQ
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(null); P{--R\
List items = X>Vc4n<}
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criteria.setFirstResult(startIndex).setMaxResults R>*z8n
}! EVf
(pageSize).list(); VD$5 Djq
PaginationSupport ps = ;NR|Hi]
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new PaginationSupport(items, totalCount, pageSize, PqV
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startIndex); kU[hB1D5
return ps; >UvP/rp
} `*3A7y
}, true); 1EXT^2!D
} {+WBi(=W
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public List findAllByCriteria(final d ItfR'$
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DetachedCriteria detachedCriteria){ ]~aj
return(List) getHibernateTemplate =/Gd<qz3
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().execute(new HibernateCallback(){ u%~'+=
publicObject doInHibernate 9j:]<?D,A
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(Session session)throws HibernateException { In1W/?
Criteria criteria = -G.N
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detachedCriteria.getExecutableCriteria(session); .; F<X\_
return criteria.list(); wa8jr5/k"
} '#7k9\
}, true); %JM$]
} 0]4X/u#N
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public int getCountByCriteria(final ,)1C"'
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DetachedCriteria detachedCriteria){ ^I!Z)/
Integer count = (Integer) ~JT`q:l-q
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getHibernateTemplate().execute(new HibernateCallback(){ \}$|Uo$O
publicObject doInHibernate ^3dc#5]Xf
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(Session session)throws HibernateException { 46=E- Tq
Criteria criteria = 3gUY13C}:p
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detachedCriteria.getExecutableCriteria(session); v 6
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return ?{ )'O+s
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criteria.setProjection(Projections.rowCount
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()).uniqueResult(); }k VC]+
} j\>&]0-Iq
}, true); 6>WkisxG
return count.intValue(); b$'%)\('g
} ~!({Unt+'
} XZOBK^,5^B
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用户在web层构造查询条件detachedCriteria,和可选的 %g7j7$c
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 'gN[LERT
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PaginationSupport的实例ps。 r.?dT |A
pss')YP.
ps.getItems()得到已分页好的结果集 oT}$N_gFT
ps.getIndexes()得到分页索引的数组 c^_+<C-F
ps.getTotalCount()得到总结果数 5i6Ji(
ps.getStartIndex()当前分页索引 #sU>L=
ps.getNextIndex()下一页索引 Ge)G.> c
ps.getPreviousIndex()上一页索引 ^X#)'\T
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 \)*\$I\]
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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 <e Y2}Ml
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一下代码重构了。 ,M]W_\N~E
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我把原本我的做法也提供出来供大家讨论吧: +v%+E{F$+
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首先,为了实现分页查询,我封装了一个Page类: "'+/ax[{
java代码: yTc&C)Jba
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/*Created on 2005-4-14*/ kJ* N`=
package org.flyware.util.page; jz3f{~
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/** k(`> (w
* @author Joa u$qasII
* p>U= Jg
*/ auB+ g'l
publicclass Page { ,*[N_[
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/** imply if the page has previous page */ c*w0Jz>@.7
privateboolean hasPrePage; s_Z5M2o
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/** imply if the page has next page */ MTR+|I3V
privateboolean hasNextPage; z3^gufOkQ
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/** the number of every page */ A'uubFRL2[
privateint everyPage; K=4|GZ~p}`
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/** the total page number */ cNKGEm
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privateint totalPage; {iQ4jJ`n
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/** the number of current page */ -lfbn=3
privateint currentPage; ),,0T/69+9
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/** the begin index of the records by the current #|V)>")
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query */ R-k~\vCW
privateint beginIndex; Yi`DRkp]3
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/** The default constructor */ 1O2V!?P
public Page(){ pCeCR
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} ^C2SLLgeJ
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/** construct the page by everyPage d|sf2
* @param everyPage
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* */ (F#2z\$;
public Page(int everyPage){ .|:R#VW
this.everyPage = everyPage; kb\\F:w(W
} 2%-/}'G*
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/** The whole constructor */ bhKe"#m|S
public Page(boolean hasPrePage, boolean hasNextPage, B?d+^sz]
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int everyPage, int totalPage, {P ==6/<2o
int currentPage, int beginIndex){ .07kG]
this.hasPrePage = hasPrePage; YCG$GD
this.hasNextPage = hasNextPage; 0|mCk
this.everyPage = everyPage; !#4b#l(e6
this.totalPage = totalPage; ddlF4L_
this.currentPage = currentPage; ! ^aJS'aq
this.beginIndex = beginIndex; Jb|dpu/e
} ?{1& J9H
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/** ,H]S-uK~
* @return o}L\b,])
* Returns the beginIndex. 5QG?*Z~?7
*/ wYd{X 8$
publicint getBeginIndex(){ SM.KM_%K
return beginIndex; ZkF6AF
} PSU}fo
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/** u y13SkW
* @param beginIndex g7v(g?
* The beginIndex to set. =AX"'q
*/ 15kkf~Z<t
publicvoid setBeginIndex(int beginIndex){ +o K*5 Y
this.beginIndex = beginIndex; 55zy]|F"
} _rW75n=3b7
}k@SmO8
/**
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* @return =A_fL{ SM
* Returns the currentPage. &[5pR60
*/ RVh{wg
publicint getCurrentPage(){ YLb$/6gj6
return currentPage; ~L"?C
} ZDm Y${J
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/** e_IRF+>
* @param currentPage HnKXO
* The currentPage to set.
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*/ G
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publicvoid setCurrentPage(int currentPage){ pL2{zW`FDh
this.currentPage = currentPage; L fZF
} ^`bMFsP
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/** wQ81wfr1:
* @return Dv~jVI Xu
* Returns the everyPage. <4582x,G
*/ yV*4|EkvW
publicint getEveryPage(){ ^p3W}D
return everyPage; Y;kiU
} ^95njE`>t`
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/** 1o?uf,H7O
* @param everyPage >+):eBL
* The everyPage to set. z#2n+hwE
*/ S:1g(f*85
publicvoid setEveryPage(int everyPage){ ]88qjKL
this.everyPage = everyPage; KtHkLYOCG
} Nt/hF>"7
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/** I
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* @return "<LWz&e^^
* Returns the hasNextPage. ilAhw4A
*/ %*#+(A"V
publicboolean getHasNextPage(){ <>)N$$Rx&
return hasNextPage; t(jE9t|2e6
} bAwKmk9C
4issj$
/** KD?b|y@
* @param hasNextPage '.&Y)A6!
* The hasNextPage to set. w^U{e
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*/ <~uzKs0
publicvoid setHasNextPage(boolean hasNextPage){ (>NZYPw^3
this.hasNextPage = hasNextPage; b`@J"E}
} na"!"C
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/** J_?v=dW`
* @return 216$,4i
* Returns the hasPrePage. 9Vo*AK'&U
*/ ZJ.an%4
publicboolean getHasPrePage(){ n2EPx(~
return hasPrePage; Qj*.Z4ue
} `.J17mQe"
A\#z<h[>
/** 3&nN;4~Zx6
* @param hasPrePage /(.:l +[w[
* The hasPrePage to set. C511hbF
*/ O1bW, n(
publicvoid setHasPrePage(boolean hasPrePage){ cvG*p||
this.hasPrePage = hasPrePage; gn&Zt}@[
}
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/** <f M}Kk
* @return Returns the totalPage. b $JS|
* D:f=Z?L)>
*/ 5doi4b>]!
publicint getTotalPage(){ w jD<"p;P
return totalPage; @XXPJq;J
} gWzslgO6
_OyQ:>M6P
/** EK Vcz'w
* @param totalPage N2"B\
* The totalPage to set. kS8?N`2}LV
*/ M/dgW`c
publicvoid setTotalPage(int totalPage){ X;N?L%Pp
this.totalPage = totalPage; R$8{f:Pj
} 3h d30o
5l
3PAG
} Uq$/Q7
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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 2Y23!hw
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个PageUtil,负责对Page对象进行构造: o_BTo5]
java代码: ]i$y;]f
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/*Created on 2005-4-14*/ 9<.O=-1~
package org.flyware.util.page; G
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import org.apache.commons.logging.Log; 8 O9^g4?
import org.apache.commons.logging.LogFactory; $t.oGd@N
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/** z R?R,k)m
* @author Joa N*}soMPV^.
* "u!gfG?oH
*/ 5MaN
{*)l
publicclass PageUtil { ,<t.Iz%
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privatestaticfinal Log logger = LogFactory.getLog j'z#V_S
x2"1,1%H7
(PageUtil.class); ,s #~00C|
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/** kg]6q T;Y
* Use the origin page to create a new page J&>@>47
* @param page _w4G|j$C
* @param totalRecords DJ, LQj
* @return !HDb{f
*/ OX]$Xdb2:
publicstatic Page createPage(Page page, int F tIcA"^N
)OV0YfO
totalRecords){ ^[xcfTN
return createPage(page.getEveryPage(), *=!e,
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page.getCurrentPage(), totalRecords); _Hv+2E[4Z
} "=Br&FN{|
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/** 2e1KF=N+
* the basic page utils not including exception -+rzc&h
H`CID*Ji
handler (SBhU:^h
* @param everyPage 4`5yrCd
* @param currentPage 10FiA;
* @param totalRecords xak)YOLRV
* @return page e?]5q ez
*/ $y8-JR~
publicstatic Page createPage(int everyPage, int t5-O-AI[b{
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currentPage, int totalRecords){ pmNy=ZXx
everyPage = getEveryPage(everyPage); =8\.fp
currentPage = getCurrentPage(currentPage); 7Z< ~{eD,
int beginIndex = getBeginIndex(everyPage, U N9hZ>9
32YbBGDN!f
currentPage); dht0PZdx?
int totalPage = getTotalPage(everyPage, 8<6H2~5<
j7~FR{:j
totalRecords); n3a.)tcC
boolean hasNextPage = hasNextPage(currentPage, ^e.-Ji
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totalPage); 4Z)s8sD KW
boolean hasPrePage = hasPrePage(currentPage); p%Z:SZZ
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returnnew Page(hasPrePage, hasNextPage, tk"+ u_u w
everyPage, totalPage, Fv$tl)p*
currentPage, T}#iXgyx
u R0UfKK
beginIndex); {X!OK3e
} xlI=)ak{
5C Dk5B_
privatestaticint getEveryPage(int everyPage){ 'R7 \
return everyPage == 0 ? 10 : everyPage; U2
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} ~aob@(
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privatestaticint getCurrentPage(int currentPage){ 6mM9p)"$
return currentPage == 0 ? 1 : currentPage; cLtVj2Wb
} 39X~<\&'
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privatestaticint getBeginIndex(int everyPage, int KdVKvs[
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currentPage){ ]~TsmR[
return(currentPage - 1) * everyPage; @>2pY_
} &hOz(825r
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privatestaticint getTotalPage(int everyPage, int jZXa
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totalRecords){ G3.aw
int totalPage = 0; /"{d2
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if(totalRecords % everyPage == 0) Z
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totalPage = totalRecords / everyPage; 4E$MhP
else /5@YZ?|#2
totalPage = totalRecords / everyPage + 1 ; Uj!3MF
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return totalPage; F? #3
} mQ[$U
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privatestaticboolean hasPrePage(int currentPage){ aacy5E
return currentPage == 1 ? false : true; E>~R P^?Uz
} =?i?-6M
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privatestaticboolean hasNextPage(int currentPage, )qWwh)\;!
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int totalPage){ z*.AuEK?
return currentPage == totalPage || totalPage == Kd\0nf6
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0 ? false : true; O. * 0;5
} 3?93Pj3oPt
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} *$Q>Om]
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 T7[@ lMa?
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 Y=S0|!u
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做法如下: rj4@
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 bt}8ymcG
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的信息,和一个结果集List: qCs/sW
java代码: ~ k*]Z8Z
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/*Created on 2005-6-13*/ 8ro`lX*F@2
package com.adt.bo; ~
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import java.util.List; osp~)icun
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import org.flyware.util.page.Page; iI GK"}
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/** J;4x$BI
* @author Joa 9q;O`&
*/ @Q1!xA^S
publicclass Result { @-@Coy 4Tt
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private Page page; x@#>l8k?
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private List content; a%#UF@I
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/** U,rI/'
* The default constructor 4$-R|@,|_
*/ tU4#7b:Y
public Result(){ M;A_'h?Z
super(); M5bE5C
} BMp'.9Qgm
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/** P(T-2Ux6
* The constructor using fields !W}sOK7#
* 1AJ6NBC&c
* @param page Dk
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* @param content 4"&-a1N
*/ fJFNS
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public Result(Page page, List content){ XYU5.
this.page = page; z5@XFaQ
this.content = content; zTng]Mvx
} 7Ae`>5B#
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/** 4[lFurH
* @return Returns the content. w:\} B'u
*/ 4\z@Evm
publicList getContent(){ e-dkvPr
return content; :9&