Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 vz@QGgQ9~2
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 guFR5>-L
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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 Y z%=
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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 [~jhOv^
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。 ?%;uR#4
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分页支持类: kTFN.kQx@
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java代码: P#EqeO
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package com.javaeye.common.util; JTz1M~
@&h<jM{D
import java.util.List; BDB-OJ
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publicclass PaginationSupport { '# (lq 5
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publicfinalstaticint PAGESIZE = 30; li; P,kg$
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privateint pageSize = PAGESIZE; IXzad
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privateList items; $F/&/Aa
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privateint totalCount; 4&`66\p;
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privateint[] indexes = newint[0]; %t<Y6*g
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privateint startIndex = 0; 1J<-P9 vk+
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public PaginationSupport(List items, int Odbjl[>k
C*c=@VAa
totalCount){ 8<_WtDg
setPageSize(PAGESIZE); q*'hSt@+D
setTotalCount(totalCount); 4)XN1r:
setItems(items); lg!1q8
setStartIndex(0); (:[><-h.
} zIdQ^vm8Q
*>\RGL;]8
public PaginationSupport(List items, int Z;%qpsq
kMI\GQW
totalCount, int startIndex){ Ex@#!fz{%
setPageSize(PAGESIZE); Sb,{+Wk
setTotalCount(totalCount); RNi&OG(
setItems(items); Oe;9[=L[
setStartIndex(startIndex); <(^-o4Cl
} mTs[3opg
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public PaginationSupport(List items, int i]1[eGF
)<3WVvB
totalCount, int pageSize, int startIndex){ 3>S.wyMR4
setPageSize(pageSize); H;$w^Tr
setTotalCount(totalCount); 5[Q44$a{
setItems(items); B}?/oZW4
setStartIndex(startIndex); N%Lh_2EzqV
} F htf4
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publicList getItems(){ O#k?c }
return items; e7hPIG
} _L:
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publicvoid setItems(List items){ >,~JQ%1
this.items = items; xJO[pT v
} G`)I _uO
u
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publicint getPageSize(){ ! Noabt
return pageSize; 8fDnDA.e
} OZISh?
tcRK\
publicvoid setPageSize(int pageSize){ y:v0&9L
this.pageSize = pageSize; q.g!WLiI
} M8g=t[\
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publicint getTotalCount(){ c<4pu
return totalCount; bAW;2
NB
} H=wmN0s{<
K
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publicvoid setTotalCount(int totalCount){ Kh5:+n_X
if(totalCount > 0){ *1elUI2Rg
this.totalCount = totalCount; !\!fd(BN
int count = totalCount / 2+Fq'!
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s
pageSize; }Y-f+qX*
if(totalCount % pageSize > 0) wuh$=fya
count++; Fa>Y]Y0r
indexes = newint[count]; @c{Z?>dUc#
for(int i = 0; i < count; i++){ 31bKgU{
indexes = pageSize * ]cA){^.Jz
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i; #G]s.by('
} ^K;,,s;0
}else{ 9MGA#a
this.totalCount = 0; 73]%^kx=
} %n-LDn
} yyiZV\ /
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publicint[] getIndexes(){ 3z5,4ps
return indexes; t[^}/
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} X@\! \
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publicvoid setIndexes(int[] indexes){ _@d.wfM
this.indexes = indexes; !E$S&zVMQ
} 55yP.@i9J
a?D\H5TF-
publicint getStartIndex(){ 5g/WQo\
return startIndex; D6v0n6w
} );$~/H4
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publicvoid setStartIndex(int startIndex){ P~]BB.tog
if(totalCount <= 0) 38 B\ \
this.startIndex = 0; F1/f:<}
elseif(startIndex >= totalCount) 6?hv,^
this.startIndex = indexes
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[indexes.length - 1]; `;i|
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elseif(startIndex < 0) hz )L+
this.startIndex = 0; u2!8'-Ai
else{ qOk4qbl[
this.startIndex = indexes
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IG#=}q
[startIndex / pageSize]; g\X"E>X
} P=S)V
} ~){*XJw6
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publicint getNextIndex(){ /n:s9eq
int nextIndex = getStartIndex() + > m5j.GP;
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pageSize; qAG0t{K
if(nextIndex >= totalCount) ~_h4|vG
return getStartIndex(); ty7a&>G
else )iEK7d^-
return nextIndex; yqB{QFXO
} 46$u}"E
(}Gl'.>\M
publicint getPreviousIndex(){ \8<bb<`
int previousIndex = getStartIndex() - W]rXt,{&
HeF[H\a<
pageSize; 8U=M.FFp
if(previousIndex < 0) %P yU3
return0; iRPd=)
else @++
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return previousIndex; ( XE`,#
} ~A"ODLgU9
{;z3$/JB
} )V9$ P)
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抽象业务类 hJaqW'S
java代码: bt~-=\
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/** F,4Q
* Created on 2005-7-12 &A%#LVjf
*/ xb1)ZJH
package com.javaeye.common.business; (VC_vz-
mp@ JsCU
import java.io.Serializable; ,`H=%#
import java.util.List; 'jmcS0f
-
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import org.hibernate.Criteria; sRY: 7>eg
import org.hibernate.HibernateException; @ZT25CD
import org.hibernate.Session; +mAMCM2N
import org.hibernate.criterion.DetachedCriteria; }g(aZ
import org.hibernate.criterion.Projections; ?#]c{Tlpz
import YB)1dzU
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org.springframework.orm.hibernate3.HibernateCallback; m>UJ; F
import EStHl(DUPq
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org.springframework.orm.hibernate3.support.HibernateDaoS (|bht 0
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upport; rLP4l~V
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import com.javaeye.common.util.PaginationSupport; E<~/AReo
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public abstract class AbstractManager extends 0Z9jlwcQ
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HibernateDaoSupport { (<1DPpy95O
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privateboolean cacheQueries = false; 12cfqIo9
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privateString queryCacheRegion; Wx:_F;
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publicvoid setCacheQueries(boolean
)5]z[sE
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cacheQueries){ ,[~Ydth
this.cacheQueries = cacheQueries; to,=Q8)0
} gR1X@j$_
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publicvoid setQueryCacheRegion(String kqHh@]Z0'
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queryCacheRegion){ PqvwM2}4
this.queryCacheRegion = $aGK8%.O
W*8D@a0 _
queryCacheRegion; 1eT|
} _+^3<MT
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publicvoid save(finalObject entity){ 6x -PGq
getHibernateTemplate().save(entity); 5X~ko>
} V&GFGds
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publicvoid persist(finalObject entity){ }KZ/>Z;^
getHibernateTemplate().save(entity); b6NttY!3
} 8N|*n"`}
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publicvoid update(finalObject entity){ EiT
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getHibernateTemplate().update(entity); Jr1^qY`0+
} mM}|x~\R
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publicvoid delete(finalObject entity){ b^A&K@[W#,
getHibernateTemplate().delete(entity); o AQ92~b
} 0.+iVOz+Y
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publicObject load(finalClass entity, +mxs jcq0
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finalSerializable id){ Ro%S_!
return getHibernateTemplate().load +>I4@1qC-|
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(entity, id); Y!Z@1V`
} |y=CmNG,
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publicObject get(finalClass entity, OFUN hbg
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finalSerializable id){ N ~LR
return getHibernateTemplate().get _I'O4s1S
8YYY *>
(entity, id); KY_qK)H
} .h*&$c/l
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publicList findAll(finalClass entity){ Y,)9{T
return getHibernateTemplate().find("from r3*wH1n
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" + entity.getName()); O|gb{
} DR =>la}!
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publicList findByNamedQuery(finalString Pu*st=KGB
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namedQuery){ huN(Q{fj
return getHibernateTemplate @MN>ye'T
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().findByNamedQuery(namedQuery); c85B-/
} )3u[btm
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publicList findByNamedQuery(finalString query, "4r5 n8
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finalObject parameter){ |-e=P9,
return getHibernateTemplate iP_rEi*-J
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().findByNamedQuery(query, parameter); se)I2T{J
} 4&&j7$aV
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publicList findByNamedQuery(finalString query, xw?G?(WO
t zV"|s=o
finalObject[] parameters){ JG4&eK$-
return getHibernateTemplate neZ_TT/3K
)p!dqlK
().findByNamedQuery(query, parameters); 'ugG^2Y
} DPe`C%Oc1
4Uwt--KtFh
publicList find(finalString query){ (+Uo;)~!YC
return getHibernateTemplate().find o/&:w z
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(query); 50'6l
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} c=|
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cb
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publicList find(finalString query, finalObject rre;HJGEL
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parameter){ ' u0{h
return getHibernateTemplate().find HX
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(query, parameter); oVsl,V
} $[]=6.s
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public PaginationSupport findPageByCriteria ivGxtx
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(final DetachedCriteria detachedCriteria){ N;D+]_;0|
return findPageByCriteria "#JoB X@yE
'kUrSM'*$N
(detachedCriteria, PaginationSupport.PAGESIZE, 0); $MsM$]~
} OPjscc5
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public PaginationSupport findPageByCriteria 8[y7(Xw
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(final DetachedCriteria detachedCriteria, finalint d&U;rMEv
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startIndex){ =0v{+#}
return findPageByCriteria )<Yy.Z_:DC
jEI!t^#
(detachedCriteria, PaginationSupport.PAGESIZE, .^v7LF]Q
LB M:>d5
startIndex); dYO87n
} ry
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public PaginationSupport findPageByCriteria Nd6N:1-
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(final DetachedCriteria detachedCriteria, finalint \zoJr)
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pageSize, _p~
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finalint startIndex){ z?i82B[Tm
return(PaginationSupport) _e-a>y
@{$SjR8Q $
getHibernateTemplate().execute(new HibernateCallback(){ i?|SC=
publicObject doInHibernate Ao]F_hZ
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(Session session)throws HibernateException { "5YsBih
Criteria criteria = y24 0 +;a
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detachedCriteria.getExecutableCriteria(session); w}2yi#E[
int totalCount = dvxH:,
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((Integer) criteria.setProjection(Projections.rowCount 6: M
;aFQP:l/
()).uniqueResult()).intValue(); lc/2!:g
criteria.setProjection t
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(null); LXx3
List items = !}vz_6)
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criteria.setFirstResult(startIndex).setMaxResults b0&dpMgh:
?}Mv5SO
(pageSize).list(); 20Rgw
PaginationSupport ps = :{Y,Nsa
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new PaginationSupport(items, totalCount, pageSize, cq!>B{
&2Y>yFB
,
startIndex); = F:d#j>F
return ps; 8m6L\Z&
} K1C#
}, true); CBF>157B
} >o[T#U
#ob">R
public List findAllByCriteria(final hxtu^E/
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DetachedCriteria detachedCriteria){ (*M(gM{;
return(List) getHibernateTemplate 8,H
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().execute(new HibernateCallback(){ lc'Jn$O@
publicObject doInHibernate .rMGI"
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(Session session)throws HibernateException { [qb#>P2G3
Criteria criteria = \@80Z5?n
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detachedCriteria.getExecutableCriteria(session); K3@UoR
return criteria.list(); t[DXG2&
} )X7ZX#ttH
}, true); D)mqe-%1
} '7xY,IY
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public int getCountByCriteria(final Jl4zj>8~
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DetachedCriteria detachedCriteria){ &KD
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Integer count = (Integer) _-h3>.;h9
Karyipn}
getHibernateTemplate().execute(new HibernateCallback(){ .+8w\>w6g
publicObject doInHibernate E.BMm/WH
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(Session session)throws HibernateException { {j(,Q qB;f
Criteria criteria = L>PpXTWwy
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detachedCriteria.getExecutableCriteria(session); p2cKtk+
return x JepDCUJ>
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criteria.setProjection(Projections.rowCount A\?O5#m:$
.E@yB`AR
()).uniqueResult(); AMkjoy3+]
} uEk$Y=p7!
}, true); W"~G]a+
return count.intValue(); rK`*v*
} Ddu$49{S:
} kgA')]
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用户在web层构造查询条件detachedCriteria,和可选的 x0 j$]$
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 p;C`n)7P7
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PaginationSupport的实例ps。 6>KDK<5NQ
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ps.getItems()得到已分页好的结果集 PDtaL
ps.getIndexes()得到分页索引的数组 <Z}2A8mjY
ps.getTotalCount()得到总结果数 @90)
ps.getStartIndex()当前分页索引 >
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ps.getNextIndex()下一页索引 ]ErAa"?
ps.getPreviousIndex()上一页索引 :vm*miOF
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ;Qw>&24h[
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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 p6>3
p
qex.}[
一下代码重构了。 "Z#&A
I]zCsT.
我把原本我的做法也提供出来供大家讨论吧: )|*HkdF`
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首先,为了实现分页查询,我封装了一个Page类: $n>.;CV
java代码: qy.Mi{=~:
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/*Created on 2005-4-14*/ #lF8"@)a-$
package org.flyware.util.page; s,lrw~17
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/** eB5;wH
* @author Joa |wWBV{^
* `a
*/ zQ5'q
publicclass Page { U
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`6;`
/** imply if the page has previous page */ #_|6yo}
privateboolean hasPrePage; bT0CQ_g21
h_fA
/** imply if the page has next page */ =Cu!
privateboolean hasNextPage; "Bn!<h}mg
-Y;(yTtz
/** the number of every page */ 5%uLs}{\q
privateint everyPage; ~
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Nx,.4CI
/** the total page number */ O57
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privateint totalPage; He~)i)co
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6
/** the number of current page */ ^jq QG+`?
privateint currentPage; jDOB(fE
%Q]m6ciAM
/** the begin index of the records by the current 3)p#}_u{
RCgZ GP
query */ ?/5WM%
privateint beginIndex; 3~%9;.I3!
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/** The default constructor */ SfEgmp-m
public Page(){ w%KU@$
wtIXZUx
} AEp|#H'
>
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/** construct the page by everyPage !S$LRm\'
* @param everyPage <"X\~
* */ 7c5+8k3
public Page(int everyPage){ jgK8} C
this.everyPage = everyPage; +?DP r
} MZl6J
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/** The whole constructor */ !^:b?M
public Page(boolean hasPrePage, boolean hasNextPage, 'QeCJ5p]
r[ni{&
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int everyPage, int totalPage, !.Eua3:V*
int currentPage, int beginIndex){ 4'Potv@/
this.hasPrePage = hasPrePage; |@!4BA
this.hasNextPage = hasNextPage; !EB<e5}8wK
this.everyPage = everyPage; F4 `ud;1H
this.totalPage = totalPage; 4|ML#aRz
this.currentPage = currentPage; _H}8eU
this.beginIndex = beginIndex; PuYAoKG
} e5W 8YNA
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/** #R-l2OO^]
* @return A]c'`Nf
* Returns the beginIndex. @FO=0_;y
*/ )O;6S$z9Y
publicint getBeginIndex(){ vtk0 j
return beginIndex; .hPk}B/KV
}
= ss(~[
]
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/** J2W#vFe\
* @param beginIndex Z8IY!d
* The beginIndex to set. 4L)#ku$jW
*/ bys5IOP{]o
publicvoid setBeginIndex(int beginIndex){ KW`^uoY$
this.beginIndex = beginIndex; o"wvP~H
} "tdF#>x
{wA(%e3_
/** EX@wenR
* @return gc,%A'OR^<
* Returns the currentPage. h9-^aB$8^
*/ 5 6w6=Is
publicint getCurrentPage(){ NhG?@N
return currentPage; 8vRQ_
} -]n\|U<
t}6QU
/** %wil'
* @param currentPage .6C9N{?Tqf
* The currentPage to set. %'+}-w
*/ :O)\+s-
publicvoid setCurrentPage(int currentPage){ BRSIg]
this.currentPage = currentPage; inQ1$
} {+Zj}3o
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/** ^jhc(ZW"
* @return GW{e"b/x
* Returns the everyPage. &;3iHY;
*/ `O,^oD4
publicint getEveryPage(){ f(S9>c2
return everyPage; 94.|l
} Y(mnGaVn
x_L5NsO:
/** 1egq:bh
* @param everyPage (sDZ&R
* The everyPage to set. vd{ban9
*/ 'Hf+Y/`
publicvoid setEveryPage(int everyPage){ <DR$WsDG
this.everyPage = everyPage; 12]rfd
} ]Xm+-{5?!R
ExKyjWAJ
/** u0;k_6N
* @return Nhf@Y}Cu
* Returns the hasNextPage. /M2U7^9``"
*/ 3R>"X c
publicboolean getHasNextPage(){ /0m0""
return hasNextPage; aoUz_7
} Wr+/9
V
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/** :;Xh`br
* @param hasNextPage \JLea$TM:
* The hasNextPage to set. )gVz?-u+D
*/ GHWt3K:*w
publicvoid setHasNextPage(boolean hasNextPage){ @b&_xT
this.hasNextPage = hasNextPage; um,G^R
} ^vw[z2"
M!R=&a=Z
/** -y|*x-iZ
* @return 1`Z:/]hl
* Returns the hasPrePage. joA>-k04
*/ ls({{34NF
publicboolean getHasPrePage(){ slnvrel
return hasPrePage; (&i
c3/-
} ]WYddiF
vJj}$AlI
/** Yr)<1.K4,M
* @param hasPrePage #J'V,_wH
* The hasPrePage to set. 7TtDI=f
*/ B4/\=MXb
publicvoid setHasPrePage(boolean hasPrePage){ ()^tw5e'^
this.hasPrePage = hasPrePage; {F=`IE3)w
} ]bP1gV(b-
JA09 o(
/** :JXGgl<y
* @return Returns the totalPage. @rP#ktz]
* f
= 'AI
*/ hG2WxYk
publicint getTotalPage(){ |mQC-=6t;Y
return totalPage; \_)[FC@
} M{t/B-'4
:z-?L0C=0
/** fl8eNiE|
* @param totalPage :sX4hZK=G
* The totalPage to set. 9
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|]
*/ qTz5P
publicvoid setTotalPage(int totalPage){ SFjR SMi
this.totalPage = totalPage; MX"M2>" pT
} %RX!Pi}5+g
]T=o >%
} &3Ry0?RET
zeshM8=
5cj&D74o
nxJx 8d"
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 2)Q%lEm`SP
;TKsAU
个PageUtil,负责对Page对象进行构造: 2WS Wfh
java代码: Tmk'rOg5
9^CuSj
q*<FfO=eQ
/*Created on 2005-4-14*/ e$`;z%6y
package org.flyware.util.page; }XD=N#p@z
0.wNa~_G|
import org.apache.commons.logging.Log; bE!z[j]
import org.apache.commons.logging.LogFactory; b63DD(
+h? Gps
/** ]u.)6{
* @author Joa aJJ)ZP2+
* W[LQ$uj
*/ FwV5{-(
publicclass PageUtil { I@kMM12>c
8iPA^b|sz{
privatestaticfinal Log logger = LogFactory.getLog <9[>+X
J;k8 a2$_
(PageUtil.class); E J&w6),d
a+B3`6
/** * $|9e
* Use the origin page to create a new page jA3xDbM
* @param page 3F9 dr@I.7
* @param totalRecords lQL/I[}
* @return B$G9#G6pZ
*/ )&[ol9+\
publicstatic Page createPage(Page page, int r.' cjUs
/ &em%/
totalRecords){ O{Z
bpa^
return createPage(page.getEveryPage(), LYuMR,7E
_6`H`zept
page.getCurrentPage(), totalRecords); +.a->SZ5"
} *iUR1V Y
g6h=Q3@
/** ;y;UgwAM
* the basic page utils not including exception M1eM^m8U
$ VeQvm*
handler L;U?s2&Y
* @param everyPage $*j)ey>
* @param currentPage t;
@T~%
* @param totalRecords G)gPL]C0
* @return page BSY7un+`:
*/ b~;M&Y
publicstatic Page createPage(int everyPage, int {tuGkRY2~
UAds$9
currentPage, int totalRecords){ hM[I}$M&O
everyPage = getEveryPage(everyPage); 1`9'.w+r
currentPage = getCurrentPage(currentPage); KkSv23In
int beginIndex = getBeginIndex(everyPage, h`D+NZtWm
d z\yP
v~
currentPage); +
7nA; C
int totalPage = getTotalPage(everyPage, yG<Q t+D
^=
'+#|:
totalRecords); $*7AG
boolean hasNextPage = hasNextPage(currentPage, 7G%^8
ce{!
v"sN
K
totalPage); #&Zj6en}M]
boolean hasPrePage = hasPrePage(currentPage); Gdr7d
r#c+{yY
returnnew Page(hasPrePage, hasNextPage, `L"l{^cH
everyPage, totalPage, {qFAX<{D
currentPage, [?n}?0
<$8e;:#:
beginIndex); :+ AqY(Gz
} ~Dj_N$_+9
Lmc"qFzK
privatestaticint getEveryPage(int everyPage){ lmx'w
return everyPage == 0 ? 10 : everyPage; {WuUzq`
} #Qd"d3QG
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privatestaticint getCurrentPage(int currentPage){ TYedem<$
return currentPage == 0 ? 1 : currentPage; {+ WI>3
} 51puR8AG>
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privatestaticint getBeginIndex(int everyPage, int Ekz)Nh)vGR
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currentPage){ gP=@u.
return(currentPage - 1) * everyPage; Gx-tPW}
} IJ6&*t
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privatestaticint getTotalPage(int everyPage, int ~ym-Szo
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totalRecords){ .*L_*}tno
int totalPage = 0; 'Inqa;TQz
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if(totalRecords % everyPage == 0) r%II`
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totalPage = totalRecords / everyPage; Cc` )P>L
else Q46sPMH+_
totalPage = totalRecords / everyPage + 1 ; M9wj
};vy
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return totalPage; X-5&c$hv
} 6M@m`c
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privatestaticboolean hasPrePage(int currentPage){ ^/jALA9!
return currentPage == 1 ? false : true; }"AGX
} E"b"VB
vU,
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privatestaticboolean hasNextPage(int currentPage, } mEsb?
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int totalPage){ 2_;3B4GDF
return currentPage == totalPage || totalPage == d=:&tOCg2
0& ?/TSC
0 ? false : true; g}'(V>(
} l}mzCIw%
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} b{lkl?@a
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 f*ZIBTb 9
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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 qU:Mvb^5&
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做法如下: ;PhX[y^*
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 L51uC ,QF
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的信息,和一个结果集List: `K\(I#z
java代码: H He~OxWg
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/*Created on 2005-6-13*/ OcGHMGdn
package com.adt.bo; w1P8p>vA1
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import java.util.List; K~aIY0=<
^DS+O>
import org.flyware.util.page.Page; ;COZHj9b
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/** C!aK5rqhv
* @author Joa |{H-PH*Iz
*/ >L>t$1hXM
publicclass Result { e{33%5
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private Page page; 5\$8"/H
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private List content; }w8:`g'T0/
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/** kKRZ79"7s
* The default constructor _<1uO=km6
*/ o]|a5.O
public Result(){ ^gD%#3>X
super(); CJu3h&Rp
} f,}]h~w\
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/** e(m#elX
* The constructor using fields = A;B-_c
* zg83->[
* @param page pg'3j3JW$
* @param content \;Ywr3
*/ ONw;NaE,
public Result(Page page, List content){ jPf*qe>U
this.page = page; fUgI*V
this.content = content; QR;E>eEq
} 'Nbae-pf
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/** ;n,@[v
* @return Returns the content. @dj2#
*/ P7i
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publicList getContent(){ p x1{=~V/
return content; "'
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} H#B~h4#
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/** 9(( QSX
* @return Returns the page. #}rv)
*/ Q@-7{3
public Page getPage(){ BI,j/SRK
return page; U,4:yc,)s
} a}+7MEUmZ/
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/** 3+2&@:$t
* @param content n)7olP0p
* The content to set. 1&@s2ee4
*/ 6KD
public void setContent(List content){ `2@t) :
this.content = content; o(I[_oUy\
} 007SA6xq
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/** `% x6;Ha
* @param page :+SpZ>
* The page to set. 8U07]=Bt<
*/ + fQ=G/
publicvoid setPage(Page page){ ddMSiwbY)
this.page = page; {1y-*@yU(
} "gD)Uis
} (f 0p
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2. 编写业务逻辑接口,并实现它(UserManager, ':fq
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UserManagerImpl) /2&