Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 O*)Vhw'pK
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 XBu"-(
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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 S8j{V5R'
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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 Doyx[zZ
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分页支持类: 9c,'k#k
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java代码: mQ26K~
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package com.javaeye.common.util; 9} M?P
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import java.util.List; hVAn>_(
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publicclass PaginationSupport { =BAW[%1b
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publicfinalstaticint PAGESIZE = 30; ,,Q O^j]4~
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privateint pageSize = PAGESIZE; $OkBg0
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privateList items; ^sEYOX\
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g
privateint totalCount; xvl#w
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privateint[] indexes = newint[0]; &n}f?
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privateint startIndex = 0; }1i`6`y1
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public PaginationSupport(List items, int &zeyE;/Hj
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totalCount){ _w+:Dv~*a
setPageSize(PAGESIZE); ?u=Fj_N_
setTotalCount(totalCount); j8{i#;s!"
setItems(items); rt~d6|6
setStartIndex(0); Tc &z:
} (U_ujPD ?
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public PaginationSupport(List items, int QIvVcfM^
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totalCount, int startIndex){ JZ*/,|1}EC
setPageSize(PAGESIZE); ju8q?Nyhs
setTotalCount(totalCount); bj0G5dc=
setItems(items); A _
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setStartIndex(startIndex); 0c'<3@39k|
} KNpl:g3{<Q
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public PaginationSupport(List items, int '(yAfL 9}
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totalCount, int pageSize, int startIndex){ -)]Yr #Q
setPageSize(pageSize); ~>Fu5i $i
setTotalCount(totalCount); L Mbn
setItems(items); vkd.)x`J,
setStartIndex(startIndex); 0gy/:T
} %D}kD6=
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publicList getItems(){ {V$|3m>:*
return items; D4-ifsP
} JG!mc7
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publicvoid setItems(List items){ 8 \ +T8(m
this.items = items; G"U9E5O
} 7>Ouqxh21
~tUl}
publicint getPageSize(){ kmsb hYM)
return pageSize; eH3JyzzP,
} &5spTMw8
;I 9&]
publicvoid setPageSize(int pageSize){ 6YLj^w] %
this.pageSize = pageSize; 3<Zq ]jk?n
}
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publicint getTotalCount(){ ?U5{Wa85D
return totalCount; UkT=W!cq
} T/Gz94c
B^Nf #XN(
publicvoid setTotalCount(int totalCount){ p7VTa~\zA
if(totalCount > 0){ ~u!|qM
this.totalCount = totalCount; k)= X}=w
int count = totalCount / _8riUt
]kG"ubHV?h
pageSize; V2?=4mb
if(totalCount % pageSize > 0) #ASz;$P
count++; U;V7 u/{
indexes = newint[count]; 9T}pT{~V
for(int i = 0; i < count; i++){ KL:j?.0
indexes = pageSize * "Hb"F?Yb
KRLQ #,9
i; Lh"<XYY
} }Qc@m9;bH
}else{ 3n1;G8Nf
this.totalCount = 0; "XKy#[d2
} 1N^[.=
} ^f
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ICoHI
publicint[] getIndexes(){ .hP D$o
return indexes; ARVf[BAJ-*
} 2d(e:rh]
w d^':
publicvoid setIndexes(int[] indexes){ z^q0/'
this.indexes = indexes; YTpSHpf@
} ia~HQ$'+n
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publicint getStartIndex(){ ,I$`-$_'
return startIndex; }DEg-j,F
} B5VKs,g
ygS;$2m%2
publicvoid setStartIndex(int startIndex){ !/*\}\'4
if(totalCount <= 0) r
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this.startIndex = 0; JEwa
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elseif(startIndex >= totalCount) @= Uh',F
this.startIndex = indexes GR.^glG?6
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[indexes.length - 1]; Y3cMC)
elseif(startIndex < 0) qu6D 5t
this.startIndex = 0; D|L9Vs`
else{ '!cCMTj
this.startIndex = indexes TnOggpQ6X
qIE9$7*X
[startIndex / pageSize]; 6V:U(g
} HTcb_a
} 2K6qY)/_
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publicint getNextIndex(){ 18d4fR
int nextIndex = getStartIndex() + 4 Y9`IgQ
A5RN5`}
pageSize; ]G=L=D^cK
if(nextIndex >= totalCount) qI9z;_,gNz
return getStartIndex(); K5VWt)Z#
else m6K}|j
return nextIndex; 6NuD4Ga
} _LUhZlw
=^f<v_L
publicint getPreviousIndex(){ FZ<gpIv!NS
int previousIndex = getStartIndex() - n;C
:0
K Hu+9eX
pageSize; f#"J]p
if(previousIndex < 0) 82qoGSD.
return0; EHIF>@TZ
else vHc%z$-d
return previousIndex; !r8`Yr n
} YQ)kRhFA
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} 4JXeV&5Qk'
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抽象业务类 rjAn@!|:+
java代码: r:'.nhe
t?&|8SId
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/** k[YS8g-Q
* Created on 2005-7-12 z`}qkbvi
*/ *3FKt&v 0
package com.javaeye.common.business; S-b/S5
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import java.io.Serializable; w\u=)3qyVV
import java.util.List; 8)3*6+D
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import org.hibernate.Criteria; tBWrL{xLe
import org.hibernate.HibernateException; \<>ih)J@tt
import org.hibernate.Session; 7wqK>Y1a
import org.hibernate.criterion.DetachedCriteria; [`[|l
import org.hibernate.criterion.Projections; #&k5d:
import JPUW6e07o
,0Hr2*p
org.springframework.orm.hibernate3.HibernateCallback; mh#a#<
import 4G0m\[Du
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org.springframework.orm.hibernate3.support.HibernateDaoS |O+H[;TB6
)
7@ `ut
upport; h0f;F@I
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import com.javaeye.common.util.PaginationSupport; EU;9*W<
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public abstract class AbstractManager extends
(@VMH !3
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HibernateDaoSupport { n\D&!y[]F
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privateboolean cacheQueries = false; ~<5!?6Yt
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privateString queryCacheRegion; 9YyLf ;
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publicvoid setCacheQueries(boolean U&OJXJdj
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cacheQueries){ g2ixx+`?|:
this.cacheQueries = cacheQueries; y9GoPC`z
} ]^7@}Ce_
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publicvoid setQueryCacheRegion(String 69NeQ$](
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queryCacheRegion){ }C?'BRX
this.queryCacheRegion = 2\{M:\2o
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queryCacheRegion; mdDOvm:&
} 'KL0@l
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publicvoid save(finalObject entity){ 6l
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getHibernateTemplate().save(entity); eJ-xsH*8
} p)-^;=<B3
,^< R{{{-A
publicvoid persist(finalObject entity){ &h)yro
getHibernateTemplate().save(entity); SHgN~Um
} 1(R}tRR7 R
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publicvoid update(finalObject entity){ s^9Voi.y
getHibernateTemplate().update(entity); Y\P8v
} I;(L%TT `
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publicvoid delete(finalObject entity){ [l??A3G
getHibernateTemplate().delete(entity); H$t_Xw==
} &PHTpkaam
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publicObject load(finalClass entity,
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finalSerializable id){ s!zx}
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return getHibernateTemplate().load G>}255qY
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(entity, id); AV]2euyn
} :eCwY
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publicObject get(finalClass entity, cqkV9f8Ro
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2
finalSerializable id){ !9e=_mY
return getHibernateTemplate().get ~G&dqw/.-U
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(entity, id); \*?~Yj#
} Ic<2QknmP
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publicList findAll(finalClass entity){ Q3~H{)[Kq
return getHibernateTemplate().find("from Nh|uO?&C6
=y*IfG9b
" + entity.getName()); t{9GVLZ
} 0Mm)`!TLSW
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publicList findByNamedQuery(finalString oZgjQM$YP
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namedQuery){ %wy.TN
return getHibernateTemplate h;"4+uw
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().findByNamedQuery(namedQuery); C{rcs'
} hi(;;C9
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publicList findByNamedQuery(finalString query, $h"\N$iSq
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finalObject parameter){ ]_gU#,8
return getHibernateTemplate "(O>=F&
.`eN8Dl1
().findByNamedQuery(query, parameter); C<tl/NC
} !Ai@$tl[S
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publicList findByNamedQuery(finalString query, 2/^3WY1U
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finalObject[] parameters){ *i%d,w0+
return getHibernateTemplate C&%_a~
q|(HsLs
().findByNamedQuery(query, parameters); Wac&b
} KZE,bi:~
k4J+J.|
publicList find(finalString query){ 6bC3O4Rw
return getHibernateTemplate().find SqpaFWr
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(query); bY:x8fl
} ?6U0PChy
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publicList find(finalString query, finalObject U[MA)41
#X1ND
parameter){ m-, x<bM?
return getHibernateTemplate().find WOap+
8l`*]1.W<
(query, parameter); #*Ctwl,T
} f
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public PaginationSupport findPageByCriteria UCj ld
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(final DetachedCriteria detachedCriteria){ kuP(r
return findPageByCriteria kxv1Hn"`{E
eSq.GtI
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 4V`G,W4^J
}
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iH@UTE ;
public PaginationSupport findPageByCriteria Km$\:Xo
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(final DetachedCriteria detachedCriteria, finalint #ABZ&Z
dy[X3jQB
startIndex){ j8sH|{H!Nq
return findPageByCriteria Q$"D]!G
J|7 3.&B
(detachedCriteria, PaginationSupport.PAGESIZE, 3JR+O<3D
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startIndex); 5{,<j\#L
} ef4 i:.
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public PaginationSupport findPageByCriteria $XH^~i;
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(final DetachedCriteria detachedCriteria, finalint ]`WJOx4
z
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pageSize, #RLt^$!H
finalint startIndex){ N;%6:I./
return(PaginationSupport) -KbYOb
ns4,@C$
getHibernateTemplate().execute(new HibernateCallback(){ 8&dF
publicObject doInHibernate j?QDR
0"z9Q\{}
(Session session)throws HibernateException { wMN]~|z>
Criteria criteria = A=0'Ks
a 1*p*dM#
detachedCriteria.getExecutableCriteria(session); .=;
;
int totalCount = 47/iF97
tZo} ;|~'
((Integer) criteria.setProjection(Projections.rowCount '|=;^Z7.K
zm;C\s rF
()).uniqueResult()).intValue(); X@FN|Rdh
criteria.setProjection _q^E,P
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(null); *VN6cSq
List items = a8Wwq?@
aw> #P
criteria.setFirstResult(startIndex).setMaxResults _o~nr]zx
8q7b_Pq1U
(pageSize).list(); <gBA1oRz
PaginationSupport ps = <OPArht
<#HYqR',
new PaginationSupport(items, totalCount, pageSize, hE-M$LmN@
/qw.p#
startIndex); PPsE${!
return ps; \l3h0R
} =Fl^`*n
}, true); N{>n$v}
} >
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public List findAllByCriteria(final akQ7K
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DetachedCriteria detachedCriteria){ |wj?ed$
f
return(List) getHibernateTemplate +ck}l2
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().execute(new HibernateCallback(){ i}?>g -(
publicObject doInHibernate Y<8vw
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(Session session)throws HibernateException { U/BR*Zn]*
Criteria criteria = :M5l*sIO2
zx7{U8*`<
detachedCriteria.getExecutableCriteria(session); zdH
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return criteria.list(); &+R?_Ooibk
} ehY5!D1Q
}, true); LOJAWR9$^U
} [ikOb8 G#
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public int getCountByCriteria(final Xha..r
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DetachedCriteria detachedCriteria){ gZ1?G-Q
Integer count = (Integer) bN@
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getHibernateTemplate().execute(new HibernateCallback(){ `9.r`&T6K
publicObject doInHibernate DlNX 3
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(Session session)throws HibernateException { _J [P[(ab
Criteria criteria = xkR0
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detachedCriteria.getExecutableCriteria(session); >F&47Yn
return Sa5G.^XI
)\^-2[;
criteria.setProjection(Projections.rowCount pD]OT-8
~u+9J}
()).uniqueResult(); N}YkMJy
} TuqH*{NNy9
}, true); FC"8#*x
return count.intValue(); _wL BA^d^
} WMg~Y"W
} lb1Xsgm{
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8-6L|#J#
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用户在web层构造查询条件detachedCriteria,和可选的 <rS F*
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 7J&4akT{9
L&OwPd
PaginationSupport的实例ps。 61
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ps.getItems()得到已分页好的结果集 BL58] P84
ps.getIndexes()得到分页索引的数组 xAP+FWyV
ps.getTotalCount()得到总结果数 1@=po)Hnp
ps.getStartIndex()当前分页索引 !5?<% *
ps.getNextIndex()下一页索引 *_g$MI
ps.getPreviousIndex()上一页索引 YT8F#t8
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 S#[j )U-
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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 O<W_fx8_'
-s'-eQF J
一下代码重构了。 ?P c' C
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我把原本我的做法也提供出来供大家讨论吧: !$>R j
Nl(Foya%)
首先,为了实现分页查询,我封装了一个Page类: HLHz2-lI
java代码: 7})[lL`\s
cPc</[x[W
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/*Created on 2005-4-14*/ 5QO9Q]I#_\
package org.flyware.util.page; Jqi%|,/] N
-C&P%tt Y
/** vgN&K@hJ
* @author Joa N$:8,9.z
* w"&n?L
*/ eGbGw
publicclass Page { 8kDp_si
U|j`e5)
/** imply if the page has previous page */ O!bOp=
privateboolean hasPrePage;
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, SnSW-P
/** imply if the page has next page */ G;XxBA
privateboolean hasNextPage; _2 osV[e
N=g"(%
/** the number of every page */ SOvF[,+
privateint everyPage; `n?DU;,
1 I",L&S1
/** the total page number */ Ef13Q]9|
privateint totalPage; &UlWCOo8
CQDkFQq-dq
/** the number of current page */ }f7j8py
privateint currentPage; 2jCf T>`3
2SR: FUV/
/** the begin index of the records by the current PRE|+=w$
3%=~)7cF
query */ "`1bA"E
privateint beginIndex; }?v )N).kW
)IZ~G\Ra'
hqkz^!rp
/** The default constructor */ URbletSBQ
public Page(){ ?p8_AL'RS
>t_6B~x9
} 5rZ
t}tEvh
/** construct the page by everyPage `&6dnSC},P
* @param everyPage K8Y=S12Ti
* */ 4)o
public Page(int everyPage){ c<$OA=n
this.everyPage = everyPage; EI^C{$Y
} G[q$QB+
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/** The whole constructor */ l_%6
public Page(boolean hasPrePage, boolean hasNextPage, g_COp"!~9
}txX;"/
Aj]V`B:65
int everyPage, int totalPage, FH+s s!
int currentPage, int beginIndex){ \v)+.m?n
this.hasPrePage = hasPrePage; <0q;NrvUb
this.hasNextPage = hasNextPage; by/jYg)+
this.everyPage = everyPage; *<ewS8f*6
this.totalPage = totalPage; *$ %a:q1U
this.currentPage = currentPage; UByv?KZi
this.beginIndex = beginIndex; Gjo`
} u!qP
h>OfOx/{q9
/** 85xR2 <:
* @return \6*I'|5d
* Returns the beginIndex. hTi$.y!k
*/ #|PS&}6wU
publicint getBeginIndex(){ Z!X0U7&U
return beginIndex; KRDmY+
} m$T-s|SY
vTw>JNVI
/** GYUn6P
* @param beginIndex p,i[W.dy.'
* The beginIndex to set. j]/RC(;?
*/ fMyti$1~
publicvoid setBeginIndex(int beginIndex){ oIj#>1~c%
this.beginIndex = beginIndex; ]}2ZttQ?
} F6flIG&h
i5,kd~%O
/** y>e.~5;
* @return _[ZO p ~
* Returns the currentPage. ]yPqLJ
*/ ZoZ|Ma
publicint getCurrentPage(){ 8X)Y^uGGZ
return currentPage; 9o:Lz5o
} $43qME
&m:uO^-D
/** /{--+
C
* @param currentPage Dy8r 9
* The currentPage to set. }s<4{:cv+
*/ :T
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publicvoid setCurrentPage(int currentPage){ s>n)B^64W
this.currentPage = currentPage; Ng>h"H
} dQR-H7U
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/** @A^;jk
* @return k-OPU,
* Returns the everyPage. Lrq.Ab#
*/ m#Z#
.j_2
publicint getEveryPage(){ ,>+p-M8ZL
return everyPage; WKa~[j|-K
} R/>@+
PxkOT*
/** mk+B9?;cF-
* @param everyPage SPmq4
* The everyPage to set. !6Mo]xh
*/ O2dW6bt
publicvoid setEveryPage(int everyPage){ )*x6 FfTUd
this.everyPage = everyPage; ve2u=eQ1
} @xYlS5{
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/** 5>N2:9We
* @return `W/>XZl+t
* Returns the hasNextPage. CDR@
`1-
*/ h/hmlnOQl
publicboolean getHasNextPage(){ b9<#K+L-
return hasNextPage; t$#jL5
} vJOw]cwq
' x35=@
/** !s?nJ(p
* @param hasNextPage T&o(N3lW
* The hasNextPage to set. G.d TvLv
*/ ?[Q3q4
publicvoid setHasNextPage(boolean hasNextPage){ yx&51G$
this.hasNextPage = hasNextPage; ;8{4!S&b
} #O}
,`[<
0-yp,G
/** .j<]mUY
* @return 3H6lBF
* Returns the hasPrePage. Bj-:#P@
*/ _k~KZ;l
publicboolean getHasPrePage(){ 2OR{[L*
return hasPrePage; b:]V`uF?
} T\j{Bi5 \J
8jo p_PG'
/** 90*5
5\>{
* @param hasPrePage k:F9. j%*
* The hasPrePage to set. kH7(@Pa
*/ 3e;^/kf<9
publicvoid setHasPrePage(boolean hasPrePage){ 9}F*P669f
this.hasPrePage = hasPrePage; e:n<EnT
} T@&K-UQ
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/** p(`6hWx
* @return Returns the totalPage. ~T,c"t2
* -0{r>,&Mm
*/ #S*/bao#
publicint getTotalPage(){ |\IN.W[EL
return totalPage; K<Iv:5-2
} n+q!l&&
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/** !()$8
* @param totalPage r@t9Ci=}
* The totalPage to set. Mh/dpb\Z
*/ ,*hLFaR-
publicvoid setTotalPage(int totalPage){ "ZsOd>[/
this.totalPage = totalPage; X4Ic;
} *><F'
~8P!XAU56%
} z(Pe,zES
.e=:RkI,
ADP%QTdqFJ
Et/\xL
@As[k2
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 3|4|*6
VE{3} S
个PageUtil,负责对Page对象进行构造: EGzzHIZ`!
java代码: (b~T]3Es
6ZG+ZHUC&
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/*Created on 2005-4-14*/ b TM{l.Aq3
package org.flyware.util.page; %GA"GYL9'
_%!c+f7
import org.apache.commons.logging.Log; *@v)d[z_
import org.apache.commons.logging.LogFactory; QWSTR\!
MmnOHN@.
/** ]#l/2V1
* @author Joa o(LFh[
* %gyLCTw
*/ uU <=d
publicclass PageUtil { _c*=4y
s{S4J'VW
privatestaticfinal Log logger = LogFactory.getLog 8WbgSY`
f'-i o<.
(PageUtil.class); aM2l2
UU mTOJr
/** 2w_W Adi
* Use the origin page to create a new page 8I8
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* @param page
$.PuK~}
* @param totalRecords ICs\
z
* @return %g$V\zmU
*/ /VS[pXXT|
publicstatic Page createPage(Page page, int m~P CB_ifW
/F-qP.<D,r
totalRecords){ ;":zkb{
return createPage(page.getEveryPage(), */|lJm'R
-o[x2u~n\
page.getCurrentPage(), totalRecords); =;3Sx::=
} 7/ysVWt
Hl/
QnI!
/** BuWHX>H
* the basic page utils not including exception wNtx]t_M
c5l.B#-lY
handler {VvqO7 A
* @param everyPage - UdEeZz.
* @param currentPage `U)hjQ~pP
* @param totalRecords "B4;,+4kR
* @return page 2`>T oWN!
*/ 9{}1r2xW
publicstatic Page createPage(int everyPage, int 5b/|!{
lB4GU y$
currentPage, int totalRecords){ TRQF^P3o
everyPage = getEveryPage(everyPage); Nq` C.&
currentPage = getCurrentPage(currentPage); P 8>d6;o($
int beginIndex = getBeginIndex(everyPage, xA1hfe.9
WZ7BoDa7O
currentPage); 8lb%eb]U
int totalPage = getTotalPage(everyPage, SAK!z!t
ang~<
totalRecords); Xr2ou5zAn
boolean hasNextPage = hasNextPage(currentPage, .DR<Te
(
Qcp{q
totalPage); ~ !
3I2
boolean hasPrePage = hasPrePage(currentPage); "
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qg!|l7e
returnnew Page(hasPrePage, hasNextPage, U.XNv-M
everyPage, totalPage, e~@[18
currentPage, 'fF;(?
T[uiPs/xD
beginIndex); !z<%GQ CT
} 9C[ywp
lR[qqFR
privatestaticint getEveryPage(int everyPage){ 2?,EzBeal
return everyPage == 0 ? 10 : everyPage; "D'B3; uWK
} I8/DR z$A
n;U`m$vL%
privatestaticint getCurrentPage(int currentPage){ @,u/w4
return currentPage == 0 ? 1 : currentPage; kRD%b[*d
} Zh*u(rO
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privatestaticint getBeginIndex(int everyPage, int M57T2]8,
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currentPage){ 7#U^Dx\yh
return(currentPage - 1) * everyPage; 1Q4}'0U4
} $Y_i4(
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privatestaticint getTotalPage(int everyPage, int 1~ t{aLPz
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totalRecords){ ks97k8B
int totalPage = 0; 80&.JP.
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if(totalRecords % everyPage == 0) pT1[<X!<s
totalPage = totalRecords / everyPage; S_v'hlrrT
else gV`=jAE_
totalPage = totalRecords / everyPage + 1 ; [],1lRYI9_
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return totalPage; f=!VsR2o
} {g~bQ2wDC
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privatestaticboolean hasPrePage(int currentPage){ E%v?t1>/
return currentPage == 1 ? false : true; }gMDXy}
} 4e;yG>
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privatestaticboolean hasNextPage(int currentPage, W4U@%b do
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int totalPage){ wTGbd
return currentPage == totalPage || totalPage == /43-;"%>
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0 ? false : true; E55t*^`
} =w5O&(
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} 1q3(
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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。 ELjK0pE}-
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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 V0(o~w/W%!
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做法如下: rVa?JvDO=
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Za7q$7F7Bc
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的信息,和一个结果集List: maY4g&'f
java代码: sv(f;ib
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/*Created on 2005-6-13*/ d:q +
package com.adt.bo; 5P+t^\
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import java.util.List; IU]^&e9u
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import org.flyware.util.page.Page; P;8>5;U4-
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/** ^*= 85iyo
* @author Joa N+)?$[
*/ 0hn-FH-XE
publicclass Result { 0\~Z5k`IT
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private Page page; FvuGup`w
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private List content; hv$m4,0WB
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/** {"H2 :-t<
* The default constructor 1?Aga,~k:a
*/ oM1
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public Result(){ (zYy}g#n
super(); ]:$
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} L~/qGDXC?
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/** 4Kv[e]10(
* The constructor using fields F;!2(sPS
* Q U
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* @param page G02m/8g3
* @param content %T=A{<[`
*/ zT* .jv
public Result(Page page, List content){ +wk`;0s A
this.page = page; /_-;zL
this.content = content; 'QH1=$Su
} b2&