Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 JToc("V
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 w K_I"
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 0?tn.<'B8T
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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 ?5A!/`E&%
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分页支持类: Z*}5M4
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java代码: 8%dE$smH
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package com.javaeye.common.util; &3SQVOW ~T
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import java.util.List; {PXN$p:'
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publicclass PaginationSupport { ]5+db0
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publicfinalstaticint PAGESIZE = 30; yj6o533o
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privateint pageSize = PAGESIZE; :+9KNyA
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privateList items; :jol
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privateint totalCount; vakAl;
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privateint[] indexes = newint[0]; dc.o K4G}
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privateint startIndex = 0; JP2zom
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public PaginationSupport(List items, int 'Y
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totalCount){ dU7+rc2,CU
setPageSize(PAGESIZE); (QPfrR=J4
setTotalCount(totalCount); TsPx"+>7`
setItems(items); y&HfF~
setStartIndex(0); f__r" N
} dPdodjSu,!
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public PaginationSupport(List items, int { *"I4
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totalCount, int startIndex){ ^ di[J^
setPageSize(PAGESIZE); ;\F3~rl
setTotalCount(totalCount); d+1q[,-
setItems(items); 9aED6
setStartIndex(startIndex); :|s!_G <
} G8w<^z>pTg
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public PaginationSupport(List items, int \"]vSx>
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totalCount, int pageSize, int startIndex){ Q-3o k7
setPageSize(pageSize); h}X^
setTotalCount(totalCount); ? 1OZEzA!
setItems(items); /B$9B
setStartIndex(startIndex); `aj;FrF
} 7X
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publicList getItems(){ h&$7^P
return items; td:GZ %
} kEH(\3,l
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publicvoid setItems(List items){ X=i^[?C
this.items = items; e/pZLj]M
} tevB2'3^
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publicint getPageSize(){ q~[@(+zP5
return pageSize; *}pl
} tOJK~%'
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publicvoid setPageSize(int pageSize){ '[E|3K5d
this.pageSize = pageSize; (]JZ1s|
} or?@Ti;
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publicint getTotalCount(){ aZ[
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return totalCount; 1:7 uS.
} ~
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publicvoid setTotalCount(int totalCount){ SLzxF uV
if(totalCount > 0){ 8JOfx
this.totalCount = totalCount; 'y(;:Kc
int count = totalCount / ea"!:cL(g
o"^+ i#H!
pageSize; b51{sL
if(totalCount % pageSize > 0) V Ae@P
count++; F/MzrK\':m
indexes = newint[count]; &+@~;p5F
for(int i = 0; i < count; i++){ f`zH#{u
indexes = pageSize *
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i; gnW]5#c@
} c-|~ABtEpX
}else{ 8VbHZ9Q
this.totalCount = 0; AS 5\X.%L*
} _|VWf 8?\
} *Y4h26
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publicint[] getIndexes(){ C$9+p@G6
return indexes; ,QDS_u$xi&
} r-27AJu
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publicvoid setIndexes(int[] indexes){ /%E l0X
this.indexes = indexes; gk"0r\Eq
} L*;XjacI]
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publicint getStartIndex(){ r:[N#*kK
return startIndex; 7+I%0U}m
} t<_Jx<{2
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publicvoid setStartIndex(int startIndex){ /i$-ws-
if(totalCount <= 0) wzLR]<6G
this.startIndex = 0; v35wlt^}
elseif(startIndex >= totalCount) -&4W0JK9
this.startIndex = indexes yv.Y-c=
m!{}Y]FZn
[indexes.length - 1]; cY%[UK $l
elseif(startIndex < 0) c\X0*GX
this.startIndex = 0; Jr0D:
else{ Oeua<,]Z~
this.startIndex = indexes 4WK@ap-~
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[startIndex / pageSize]; KmuE#Ia
} ~Wh}W((L
} qo1eHn4
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publicint getNextIndex(){ [iJU{W
int nextIndex = getStartIndex() + Hwr#
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pageSize; t;[L-|^
if(nextIndex >= totalCount) d2b L_
return getStartIndex(); +UzFHiGy#
else ]SNA2?q
return nextIndex; ZTCzD8
} d3A= (/>D
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publicint getPreviousIndex(){ Y2&>;ym!
int previousIndex = getStartIndex() - \(y6o}aW
#+mt}w/
pageSize; w28!Yj1Q
if(previousIndex < 0) NGl/F{<
return0; TW2OT }
else MA\^<x_?L}
return previousIndex; 71AR)6<R
} ;D Mv?-H
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} E,6(/`0H*
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抽象业务类 d/Q}I[J.u
java代码: kF:4[d
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/** 9zdp8?T
* Created on 2005-7-12 C4Pi6.wf
*/ /O"IA4O
package com.javaeye.common.business; vn n4
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import java.io.Serializable; ML6V,V/e
import java.util.List; i^c
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import org.hibernate.Criteria; Yjv[rH5v
import org.hibernate.HibernateException; f
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import org.hibernate.Session; [4)q6N5`f
import org.hibernate.criterion.DetachedCriteria; gTz66a@i
import org.hibernate.criterion.Projections; &!I^m
import xkv2#"*v
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org.springframework.orm.hibernate3.HibernateCallback; )9~1XiS,
import OrXx0Hn
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org.springframework.orm.hibernate3.support.HibernateDaoS w(w%~;\kLP
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upport; DlB"o.
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import com.javaeye.common.util.PaginationSupport; 0qXkWGB
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public abstract class AbstractManager extends L8<Yk`jx
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HibernateDaoSupport { ;Qpp[V`
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privateboolean cacheQueries = false; [m*=Q
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privateString queryCacheRegion; f
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publicvoid setCacheQueries(boolean ([loWr}QR
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cacheQueries){ $y!k)"k
this.cacheQueries = cacheQueries; NB]T~_?]*
} ^%X,Rml<e
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publicvoid setQueryCacheRegion(String \~H;Wt5
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queryCacheRegion){ \0%)eJ
this.queryCacheRegion = q7}$F]UM"
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queryCacheRegion; vkmTd4g
} .lMIJN&/
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publicvoid save(finalObject entity){ .e2qa
getHibernateTemplate().save(entity); Hu$]V*rAG
} >S / Zd
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publicvoid persist(finalObject entity){ du2q6"
getHibernateTemplate().save(entity); iqecm]Z0
} (5@9j
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publicvoid update(finalObject entity){ 5TlPs_o
getHibernateTemplate().update(entity); '>:mEXK}w
} sa\v9
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publicvoid delete(finalObject entity){ E.v~<[g
getHibernateTemplate().delete(entity); Qh%(yL!
} }Sa2s&[<
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publicObject load(finalClass entity, J-g#zs
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finalSerializable id){ 7+aTrE{
return getHibernateTemplate().load /kL X
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(entity, id); Ba/Z<1)
} H27J kZ&
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publicObject get(finalClass entity, ARYqX\-e
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finalSerializable id){ t?^C9(;6
return getHibernateTemplate().get s MAc+9G9k
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(entity, id); WXj}gL`
} DKL< "#.7
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publicList findAll(finalClass entity){ kzCD>m
return getHibernateTemplate().find("from |Ia3b VW
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" + entity.getName()); 2-821Sf#h
} \(_FGa4j
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publicList findByNamedQuery(finalString jqHg'Fq
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namedQuery){ Z(AI]wk3<
return getHibernateTemplate 11}fPWK
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().findByNamedQuery(namedQuery); Oqzz9+
} ~o`I[-g)
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publicList findByNamedQuery(finalString query, 6L~@jg~0A[
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finalObject parameter){ \ief [
return getHibernateTemplate +~J?/
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().findByNamedQuery(query, parameter); (x9d7$2
} $NP5Z0v7
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publicList findByNamedQuery(finalString query, za7h.yK }
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finalObject[] parameters){ 42LlR
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return getHibernateTemplate VAf~,T]Ww
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().findByNamedQuery(query, parameters); |i-Q fpn
} xKKL4ws
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publicList find(finalString query){ ~1YL
return getHibernateTemplate().find *&B1(&{:V
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(query); WlP#L`
} MP, l*wVd
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publicList find(finalString query, finalObject QLo^6S5!
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parameter){ +]Of f^s
return getHibernateTemplate().find ]B0>r^
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(query, parameter); j[YzBXd
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} C,C%1
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public PaginationSupport findPageByCriteria F?'=iY<h
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(final DetachedCriteria detachedCriteria){ ")7,ZN;
return findPageByCriteria L f[>U
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); l(9$s4R
} _#9:cH*
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public PaginationSupport findPageByCriteria
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(final DetachedCriteria detachedCriteria, finalint Y-&r_s_~
{
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startIndex){ Fa^5.p
return findPageByCriteria vOsd>3"
cs`/^2Vf"#
(detachedCriteria, PaginationSupport.PAGESIZE, xEaRuH c
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startIndex); 94%gg0azp
} mnL
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public PaginationSupport findPageByCriteria hu\HK81m
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(final DetachedCriteria detachedCriteria, finalint <5/r
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pageSize, 2}]6~i
finalint startIndex){ AY:3o3M
return(PaginationSupport) 8 f%@:}H
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getHibernateTemplate().execute(new HibernateCallback(){ ?RvXO'm l
publicObject doInHibernate VE^NSkOa&
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(Session session)throws HibernateException { }5bh,'
Criteria criteria = {rGq|Bj
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detachedCriteria.getExecutableCriteria(session); I"@X~Y7}
int totalCount =
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((Integer) criteria.setProjection(Projections.rowCount #/@U|g
([UuO}m-
()).uniqueResult()).intValue(); AL! ^1hCF
criteria.setProjection \(.&E`r
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(null); MQE=8\
List items = ,T"pUe VJ
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criteria.setFirstResult(startIndex).setMaxResults 'Z'X`_
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(pageSize).list(); #})Oz| c
PaginationSupport ps = $-"AMZ899
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new PaginationSupport(items, totalCount, pageSize, sF]v$kq
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startIndex); VgZ<T,SuW
return ps; Gk,{{:M:5
} MLY19 ;e
}, true); >1a-}>r
} Vj4
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public List findAllByCriteria(final !798%T
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DetachedCriteria detachedCriteria){ |K'{R'A
return(List) getHibernateTemplate %cO;{og M
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().execute(new HibernateCallback(){ x@2rfs
publicObject doInHibernate ?1 r@r
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(Session session)throws HibernateException { SDiZOypS
Criteria criteria = COFs?L.`
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detachedCriteria.getExecutableCriteria(session); \l{*1lQ`
return criteria.list(); mW1Sd#0
} p\:_E+lsU
}, true); "*laY<E
} y4,2Xs9,
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public int getCountByCriteria(final CSc*UX+
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DetachedCriteria detachedCriteria){ <?52Svi}}
Integer count = (Integer) -QIcBzw;q
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getHibernateTemplate().execute(new HibernateCallback(){ yt>Pf<AI
publicObject doInHibernate yNc>s/
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(Session session)throws HibernateException { |_F-Abk
Criteria criteria = ,TOLr%+v~n
)
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detachedCriteria.getExecutableCriteria(session); 7t5X
return %2BFbaE
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criteria.setProjection(Projections.rowCount k(=\&T
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()).uniqueResult(); #1hT#YN
} ,9|%
}, true); :m5&
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return count.intValue(); )oTEB#J
} Qat%<;P2
} FvG9PPd
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用户在web层构造查询条件detachedCriteria,和可选的 #H
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 L)8 +/+
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PaginationSupport的实例ps。 huvg'Yt
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ps.getItems()得到已分页好的结果集 H4l:L(!D
ps.getIndexes()得到分页索引的数组 bw%1*;n)
ps.getTotalCount()得到总结果数 ;zs*Zd7h M
ps.getStartIndex()当前分页索引 )@eBe^
ps.getNextIndex()下一页索引 |r}%AN6+
ps.getPreviousIndex()上一页索引 T~"tex]
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 IL.Jx:(0
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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 n/$Bd FH
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一下代码重构了。 v^@L?{"}8
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我把原本我的做法也提供出来供大家讨论吧: yl 0?Y
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首先,为了实现分页查询,我封装了一个Page类: x ?^c:`.
java代码: Z6D4VZVF
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/*Created on 2005-4-14*/ |]GEJUWtCd
package org.flyware.util.page; '0t j2
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/** Jk{>*jYk`
* @author Joa 3BY/&'oX
* /@3+zpaw X
*/ #H!~:Xu
publicclass Page { E*(Q'p9C
GGJ_,S*
/** imply if the page has previous page */ K"}Dbr
privateboolean hasPrePage; \W=
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/** imply if the page has next page */ So`xd
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privateboolean hasNextPage; @b>]q$)(}
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/** the number of every page */ {_q2kk
privateint everyPage; 46XB6z01
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/** the total page number */
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privateint totalPage; MO _9Yi
8z/ ^Ql
/** the number of current page */ @=;6:akz`
privateint currentPage; 2Cr+Z(f
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/** the begin index of the records by the current cU{LyZp
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query */ 8U;!1!+
7)
privateint beginIndex; {;p/V\
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/** The default constructor */ spl*[ d
public Page(){ 9&d BL0
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3E]
} qS2%U?S7
ux=a9
/** construct the page by everyPage yBl<E$=
* @param everyPage 8vT:icl
* */ 2sU"p5 j
public Page(int everyPage){ }s)Z:6;(,q
this.everyPage = everyPage; 92SB'T>
} ;JZXSM-3
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/** The whole constructor */ /ZzlC#`
public Page(boolean hasPrePage, boolean hasNextPage, %kc g#p+tE
RU{}qPs?
;zCHEz
int everyPage, int totalPage, TuF:m"4
int currentPage, int beginIndex){ B"qG-ci
this.hasPrePage = hasPrePage; 5=?&q 'i
this.hasNextPage = hasNextPage; ?DRC!
9o^
this.everyPage = everyPage; ]!A;-m
this.totalPage = totalPage; K[ \z'9Q
this.currentPage = currentPage; hV,3xrm?P
this.beginIndex = beginIndex; *jJ62-o
} VLO>{"{'
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/** p0tv@8C>
* @return v4v+;[a%
* Returns the beginIndex. \;?\@vo<
*/ t{7l.>kf
publicint getBeginIndex(){ b~Ruhi[E
return beginIndex; S1B/ClKWq
} m_Rgv.gE^
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/** y&CUT:M6
* @param beginIndex 9.@(&
* The beginIndex to set. 9:Y:Vx
*/ jqLyX
publicvoid setBeginIndex(int beginIndex){ RhJ<<T.2
this.beginIndex = beginIndex; D3K`b4YV
} 6
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>ciq4H43Q|
/** [qXpi'q[
* @return 7d<v\=J}
* Returns the currentPage. z=fag'fzM
*/ -?]ltn9!
publicint getCurrentPage(){ 7&QVw(:)M
return currentPage; u qyf3bK
} ryT8*}o
n (|>7
/** q-RGplx
* @param currentPage |4c==7.
* The currentPage to set. e56#Qb@$\
*/ ((5zwD
publicvoid setCurrentPage(int currentPage){ XgbGC*dQ
this.currentPage = currentPage; 7*5ctc!dG
} I,S'zHR
dL\8^L
/** w\mF2h
* @return K@i*Nl
* Returns the everyPage. 0l##M06>
*/ aE%VH ;?
publicint getEveryPage(){ H|Nw)*.
return everyPage; "5YdmBy
} LBE".+
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/** "4`%NA
* @param everyPage <oO,CXF
* The everyPage to set. G<z)Ydh_
*/ @Dy.HQ~
publicvoid setEveryPage(int everyPage){ m7"f6zSo(
this.everyPage = everyPage; c`+ITNV
}
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w|HZI,~
/** _R<HC
* @return K$.zO4
* Returns the hasNextPage. l+6\U6_)B
*/ l#"alU!<^
publicboolean getHasNextPage(){ Dr1F|[
return hasNextPage; yRYWx` G
} s]N-n?'G"
uaKB
/** 3wE8y&
* @param hasNextPage -b$OHFL
* The hasNextPage to set. Q#N+5<]J)#
*/ 1+jYpYEQW
publicvoid setHasNextPage(boolean hasNextPage){ rTm{-b)r
this.hasNextPage = hasNextPage; d.AjH9 jg
} 9yh@_~rZ
zFn&~lFB
/** `@M4THt
* @return Wa(S20yF
* Returns the hasPrePage.
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*/ 2X*<Fma3C
publicboolean getHasPrePage(){ V.#8-?z
return hasPrePage; FT;JYkO
} J$Epj
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/** !_) ^bRd
* @param hasPrePage 3~Ln:4[6ID
* The hasPrePage to set. Q.1ohj0)
*/ s]c$]&IGG
publicvoid setHasPrePage(boolean hasPrePage){ &[RU.Q!_H
this.hasPrePage = hasPrePage; 8:% R|b
} !d\GD8|4
#+
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/** m3!M L>nLt
* @return Returns the totalPage. GU3/s&9
* bY~ v0kg
*/ F29AjW86
publicint getTotalPage(){ 1%"`
=$q%
return totalPage; _zh5KP[{
} lc-|Q#$3$
X t =bc
/** E<uOk
* @param totalPage QZr<=}
* The totalPage to set. 9C;Y5E~'L
*/ h*UUtLi%WU
publicvoid setTotalPage(int totalPage){ P;%QA+%7
this.totalPage = totalPage; Hz8`)cv`
} f'O vG@
n*~
} ef&@aB
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h<;[P?z
ap^=CEf
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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 6# ";W2
h&bV!M
个PageUtil,负责对Page对象进行构造: ]Rh(=bg
java代码: 9M]"%E!s
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/*Created on 2005-4-14*/ FH8mK)
package org.flyware.util.page; #<Nvy9
NCnId}BT
import org.apache.commons.logging.Log; hxVM]e[
import org.apache.commons.logging.LogFactory; bU ]N^og^
==1/N{{R
/** K9Xd?
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* @author Joa DA)v3Nd
* 6;frIl;
*/ WgJAr73
l
publicclass PageUtil { q_y,j&
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privatestaticfinal Log logger = LogFactory.getLog 8$ZSF92C
1lyOp
(PageUtil.class); I<./(X[H:#
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/** 4>VZk^%b#
* Use the origin page to create a new page Pmlgh&Z
* @param page QX.6~*m1
* @param totalRecords |$w={N^4
* @return "P5bYq%0v
*/ $H-D9+8 7
publicstatic Page createPage(Page page, int 1 {x~iZa
@:+n6
totalRecords){ Q\#{2!I
return createPage(page.getEveryPage(), 6'Yn|A
)_*a7N!
page.getCurrentPage(), totalRecords); |sqo+E
} H!r
Kz
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/** l$VxE'&LQ
* the basic page utils not including exception cJ##K/es
k>&s(b
handler P!+nZXo
* @param everyPage A?D"j7JD=L
* @param currentPage 0t COb9
* @param totalRecords .(7C)P{.0
* @return page h2"|tTm,a
*/ %C`'>,t>
publicstatic Page createPage(int everyPage, int O
{6gNR,*
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[_
currentPage, int totalRecords){ 'SU9NQS
everyPage = getEveryPage(everyPage); 6!%d-Z7)
currentPage = getCurrentPage(currentPage); b^,Mw8KsO
int beginIndex = getBeginIndex(everyPage, x)VIA]
G:c8`*5Q
currentPage); 8#]7`o
int totalPage = getTotalPage(everyPage, i\Pr3
7
"
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totalRecords); 9MB\z"b?A
boolean hasNextPage = hasNextPage(currentPage, 6+$d
zz 'dg-F
totalPage); vN,}aV2nq
boolean hasPrePage = hasPrePage(currentPage); OKZam ik~
0^y@p&;/.
returnnew Page(hasPrePage, hasNextPage, $;2eH
everyPage, totalPage, L);||]B
currentPage, VyoE5o
>[XOMKgQ](
beginIndex); g)9JO6]
} K rr?`n
$}^\=p}X
privatestaticint getEveryPage(int everyPage){ I*W9VhIOV
return everyPage == 0 ? 10 : everyPage; 9IvcKzS2
} Xh0wWU*
c[h'`KXJf-
privatestaticint getCurrentPage(int currentPage){ 1x\VdT
return currentPage == 0 ? 1 : currentPage; O~#uQm
} >2lAy:B5
*]m kyAhi
privatestaticint getBeginIndex(int everyPage, int uZ/7t(fy
N{^>MRK=5
currentPage){ l|vWeBs
return(currentPage - 1) * everyPage; PUE'Rr(Q
} BK(pJNBh
c3zT(FgO>N
privatestaticint getTotalPage(int everyPage, int /m
Q2;*|
}+{*, z
totalRecords){ =nvAOvP{?
int totalPage = 0; *>GIk`!wM
s3Krob`C5
if(totalRecords % everyPage == 0) )iEa2uJ
totalPage = totalRecords / everyPage; 5:l*Ib:s7
else E+m]aYu"
totalPage = totalRecords / everyPage + 1 ; 9B+ zJ Vte
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return totalPage; h\=p=M
} h/1nm U]
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privatestaticboolean hasPrePage(int currentPage){ 'HQ7
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return currentPage == 1 ? false : true; }RA3$%3
} foFg((tS
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privatestaticboolean hasNextPage(int currentPage, "#-Nqq
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int totalPage){ lPRdwg-
return currentPage == totalPage || totalPage == h;EwkbDQg>
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0 ? false : true; x2j/8]'o
} (o x4K{
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} W>`g;[ W
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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。 U`bC>sCp
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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 fa!3/X+
lFp!XZ!
做法如下: 1u"R=D9p,=
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 c&7Do}
%rpR-}j
的信息,和一个结果集List: ]]p19 [4s
java代码: 5,HCeN
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'2|1%NSW9
/*Created on 2005-6-13*/ /h?<MI\7V
package com.adt.bo; 0|+>A?E}E
u<l#xud
import java.util.List; IF&g.R
O`wYMng)
import org.flyware.util.page.Page; qDby!^ryc
a.
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/** xa87xX=a
* @author Joa [;(]Jy
*/ tA`mD >[
publicclass Result { *.kj]BoO
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private Page page; !lR0w|
KWFyw>*)
private List content; ftYR,!&
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/** RH!SW2o<
* The default constructor V/aQ*V{
*/ 'RDWU7c9]
public Result(){ 'R^iKNPs
super(); ]s*5[=uc2
} 3C277nx
KqN!?anPr
/** =ud`6{R
* The constructor using fields M*d-z
* wXc,F D$
* @param page ~?FK ; (
* @param content )-0[ra]
*/
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public Result(Page page, List content){ q{a#HnZo"
this.page = page; e{,!|LhpQ
this.content = content; yJnPD/i
} ]UK`?J=t2g
:&Qb>PH[
/** 'n~fR]h}
* @return Returns the content. sS
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*/ OI~}e,[2z
publicList getContent(){ ]}BB/KQy^
return content; CfQf7-
} fH-NU-"
j h;
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[
/** 4Z*|Dsw
* @return Returns the page. riID,aut
*/ hZ!oRWIU%G
public Page getPage(){ e &d3SQ%
return page; E::L?#V
} m])Lw@#9W
jyNb(Z
/** ?#?e(mpo
* @param content g<fP:/
* The content to set. p?Z(rCp
*/ 3f_i1|>)'
public void setContent(List content){ /
>%L[RJ4
this.content = content; O4T'o.
} smV!y8&
F#6cF=};@
/** DYX-5~;!
* @param page /E)9v$!
* The page to set. Z,3 CC \
*/ <lFdexH"T
publicvoid setPage(Page page){ ]x2Jpk99a
this.page = page; ~NxEc8Y
} !&W|myN^
} ~
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h9)RJSF4
4 &|C}
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q
2. 编写业务逻辑接口,并实现它(UserManager, d5Qd'
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UserManagerImpl) :ztyxJv1
java代码: CQ<8P86gt
[KMS<4t'
*MI)]S
/*Created on 2005-7-15*/ vEF=e
package com.adt.service; SWT:frki`
r]9 e^
import net.sf.hibernate.HibernateException; TaOOq}8c#
)Lb72;!?
import org.flyware.util.page.Page; 8\DME
w$b~x4y%
import com.adt.bo.Result; 0F^]A"kF
aRX
/** 3x![8 x
* @author Joa e[}],W
*/ t~ -J %$
publicinterface UserManager { p zg&/m&F`
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public Result listUser(Page page)throws >&1um5K
<