Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 '|ad_M
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Yy5h"r
iyN:%ofh
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 oL-]3TY~
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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 uOKCAqYa
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。 ycc4W*]
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分页支持类: :v0U|\j8/V
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java代码: czA5n
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package com.javaeye.common.util; f<
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import java.util.List; Wfu(*
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publicclass PaginationSupport { RW|`nL
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publicfinalstaticint PAGESIZE = 30; \4&fxe
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privateint pageSize = PAGESIZE; 7z/|\D_{
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privateList items; %]Fd[pzF
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privateint totalCount; oNr-Q& C,
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privateint[] indexes = newint[0]; B+Rm>^CBm
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privateint startIndex = 0; b v G/|U
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public PaginationSupport(List items, int +:8fC$vVfC
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totalCount){ O&vVv _zh
setPageSize(PAGESIZE); nv GF2(;l
setTotalCount(totalCount); lun#^ J
setItems(items); J{'>uD.@
setStartIndex(0); 5BWH-2HsB
} 00'%EYO
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public PaginationSupport(List items, int TBs|r#
}d&_q7L@@6
totalCount, int startIndex){ N<|@ymi
setPageSize(PAGESIZE); lAi6sPG)0
setTotalCount(totalCount); ,">]`|?
setItems(items); .|hf\1_J
setStartIndex(startIndex); C+'/>=>a.
} mN~ci 0
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public PaginationSupport(List items, int J3,fk)
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totalCount, int pageSize, int startIndex){ Cf TfL3(J
setPageSize(pageSize); j\,EO+ZQCv
setTotalCount(totalCount); Qi^Z11
setItems(items); %Qc La//
setStartIndex(startIndex); j!_;1++q
} E7NV ^4h
4
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publicList getItems(){ 0":ib0=
return items; M|6A0m#Q
} t5[#x4
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publicvoid setItems(List items){ `)`
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this.items = items; h^?\xm|
} [f)cL6AeF
*194{ ep
publicint getPageSize(){ Rd2qe /
return pageSize; '3_]Gu-D
} *;1,5L
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publicvoid setPageSize(int pageSize){ s8wmCzB~
this.pageSize = pageSize; 7{e% u#
} qLw{?sH}J/
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publicint getTotalCount(){ wLmhy,
return totalCount; +,2:g}5
} 9
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publicvoid setTotalCount(int totalCount){ `!XY]PI+e
if(totalCount > 0){ m5L-67[sB
this.totalCount = totalCount; >*]Hq.&8
int count = totalCount / 4xk|F'6K
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pageSize; /]=C{)8
if(totalCount % pageSize > 0) [pl'| B
count++; .$Ik`[+Z
indexes = newint[count]; /`f^Y>4gD
for(int i = 0; i < count; i++){ KAC6Snu1
indexes = pageSize * ,$+lFv3LE
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i; CsTF
} WX=Jl<
}else{ "5-^l.CKH
this.totalCount = 0; XM1WfjE\
} /<HRwG\w
} lLp^Gt^}w(
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publicint[] getIndexes(){ I|>^1kr8w
return indexes; ]F; f`o
} MOsl_^c
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publicvoid setIndexes(int[] indexes){ Q?3Gk%T0[
this.indexes = indexes; F">Qpgt
} 2Tfz=7h$
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publicint getStartIndex(){ 29!q!g |
return startIndex; )Z(TCJ~~!
} RnhL<
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1
publicvoid setStartIndex(int startIndex){ zRq-b`<7V
if(totalCount <= 0) `|,`QqDQ
this.startIndex = 0; Bm"KOr$}-
elseif(startIndex >= totalCount) L1ieaKw
this.startIndex = indexes !X"K=zt"
P^w#S
[indexes.length - 1]; $/.zm;D
elseif(startIndex < 0) "Jt.lL ]5
this.startIndex = 0; UG)8D5
else{ *tgnYa[l
this.startIndex = indexes LXEfPLS
bty/
[startIndex / pageSize]; TQx.KM>y
} HRiL.DS
} 2_zp:v
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publicint getNextIndex(){ ^1Zeb$Nw'
int nextIndex = getStartIndex() + E_8\f_%wK
qQ"Fv|]~>
pageSize; cfcim.jB
if(nextIndex >= totalCount) O
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return getStartIndex(); -[6z 1"*
else g>dA$h%
return nextIndex; |lJX 3
} (N&lHLy
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publicint getPreviousIndex(){ _~*,m#uxJ
int previousIndex = getStartIndex() - .G+Pe'4a
[P 06lIO
pageSize; \T<$9aNb
if(previousIndex < 0) T}"6wywM
return0; Iz
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else q|8{@EMT
return previousIndex; iVd.f
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} ~-PjW#J%
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} n84GZ5O>7
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抽象业务类 LxpuhvIO
java代码: 'Er:a?88l
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/** ppFe-wY
* Created on 2005-7-12 lKlU-4
*/ T'LIrf
package com.javaeye.common.business; ~M\I;8ne
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import java.io.Serializable; 6e_dJ=_
import java.util.List; =e8bNg
?c7*_<W5
import org.hibernate.Criteria; ed:@C?
import org.hibernate.HibernateException; <x&%~6j
import org.hibernate.Session; Q4*fc^?u
import org.hibernate.criterion.DetachedCriteria; h;-yU.(w
import org.hibernate.criterion.Projections; $2u 'N:o
import =IUUeFv +r
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org.springframework.orm.hibernate3.HibernateCallback; :_@JA0n
import y|Ir._bt
Bf$_XG3
org.springframework.orm.hibernate3.support.HibernateDaoS XXh6^@H=
YSj+\Z$(
upport; :<Fe
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import com.javaeye.common.util.PaginationSupport; Dc+'<"
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public abstract class AbstractManager extends 4T?h
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HibernateDaoSupport { @c~)W8
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privateboolean cacheQueries = false; +n7?S~R$
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privateString queryCacheRegion; TO-nD>
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publicvoid setCacheQueries(boolean Nr0
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cacheQueries){ UK{irU|\
this.cacheQueries = cacheQueries; Z(ZiFPx2Z
} &
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$z$u{
publicvoid setQueryCacheRegion(String 7Su#Je]
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queryCacheRegion){ 5BR2?hO4
this.queryCacheRegion = ncSFj.}w]
m] W5+
queryCacheRegion; 2>\v*adG
}
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publicvoid save(finalObject entity){ 3&x-}y~sg
getHibernateTemplate().save(entity); \V>?Do7
} Y $u9%0q|?
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publicvoid persist(finalObject entity){ @ w>zF/
getHibernateTemplate().save(entity); jt@SZI`
} vfNAs>X g"
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publicvoid update(finalObject entity){ O8]'o*<]
getHibernateTemplate().update(entity); !;Jmg
} O}[PJfvBHo
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publicvoid delete(finalObject entity){ Bk}><H
getHibernateTemplate().delete(entity); 63!rUB!
} 4 V1bLm
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publicObject load(finalClass entity, o&hIHfZri
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finalSerializable id){ "C?5f]T
return getHibernateTemplate().load za'6Y*CGgX
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(entity, id); b.O9ITR
} 6r"u$i`o
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publicObject get(finalClass entity, ?4CNkk=v
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finalSerializable id){ ]l~Vi_c
return getHibernateTemplate().get ,uz ]V1
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(entity, id); L5IbExjV
} ZAuWx@}
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publicList findAll(finalClass entity){ ._z'g_c(
return getHibernateTemplate().find("from GO! uwo:
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" + entity.getName()); c~<1':
} JIO$=+p
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publicList findByNamedQuery(finalString jy2IZ o
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namedQuery){ RE 3Z%;'
return getHibernateTemplate iP3Z
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().findByNamedQuery(namedQuery); aH_6s4+:
} rAQF9O[
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publicList findByNamedQuery(finalString query, }i!pL(8;
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finalObject parameter){ 1+y"i<3)
return getHibernateTemplate $trAC@3O@
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().findByNamedQuery(query, parameter); sTHq&(hLUG
} Fs/?
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publicList findByNamedQuery(finalString query, +:jT=V"X
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finalObject[] parameters){ Q}2[hB
return getHibernateTemplate ekf$dgoR
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().findByNamedQuery(query, parameters); KT*:F(4`
} \ SCy$,m
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publicList find(finalString query){
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return getHibernateTemplate().find w3*-^: ?j
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(query); bNzqls$
} #'o7x'n^
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publicList find(finalString query, finalObject 17UK1Jx,
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parameter){ :9d\Uj,
return getHibernateTemplate().find 8LM#WIm?
u"VS* hSH
(query, parameter); q7]>i!A
} 7$T8&Mh
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public PaginationSupport findPageByCriteria ,=w!vO5s
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(final DetachedCriteria detachedCriteria){ o$bUY7_
return findPageByCriteria p%RUHN3G[
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 0'ZYO.y
} saK;[&I*
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public PaginationSupport findPageByCriteria Q9y*:
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(final DetachedCriteria detachedCriteria, finalint 6mG3fMih.
P1d,8~;
startIndex){ LDX*<(
return findPageByCriteria N~#D\X^t.
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(detachedCriteria, PaginationSupport.PAGESIZE, L{PH0Jf
8 lS($@@{
startIndex); KRk~w]
} =P_fv
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public PaginationSupport findPageByCriteria 6VR18Y!y
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(final DetachedCriteria detachedCriteria, finalint {[3YJkrM
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pageSize, 8tZ};="F
finalint startIndex){ |3@=CE7G
return(PaginationSupport) ONWO`XD
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getHibernateTemplate().execute(new HibernateCallback(){ _7 `E[&v
publicObject doInHibernate )5i*/I\
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(Session session)throws HibernateException { A}4t9|/K6
Criteria criteria = +u#Sl)F
cdp{W
detachedCriteria.getExecutableCriteria(session); 4<yK7x
int totalCount = .;Z.F7{q
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((Integer) criteria.setProjection(Projections.rowCount +E#PJ_H=F8
w{P6i<J
()).uniqueResult()).intValue(); (,TH~("{
criteria.setProjection
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(null); `t9.xB#Z
List items = th Q J(w
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criteria.setFirstResult(startIndex).setMaxResults <[5#c*A
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(pageSize).list(); V
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PaginationSupport ps = D?J#u;h~f
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new PaginationSupport(items, totalCount, pageSize, *s36OF!
500>
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startIndex); #}j]XWy
return ps; 0w+5'lOg
} L,%Z9
}, true); /[L)tj7B
} m/" J
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public List findAllByCriteria(final U>1b9G"_
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DetachedCriteria detachedCriteria){ P_mi)@
return(List) getHibernateTemplate `_0)kdu
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().execute(new HibernateCallback(){ e
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publicObject doInHibernate |thad!?
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(Session session)throws HibernateException { wU.'_SBfB
Criteria criteria = n'Bmz
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detachedCriteria.getExecutableCriteria(session); ^YqbjL
return criteria.list(); h9U+%=^O
} h2AGEg'g2[
}, true); {DSyV:
} YI/{TL8*KK
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public int getCountByCriteria(final F],TG&>5
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DetachedCriteria detachedCriteria){ qih6me8C
Integer count = (Integer) 3L*+ 8a
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getHibernateTemplate().execute(new HibernateCallback(){ "Jf4N
publicObject doInHibernate Zb}`sk#
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(Session session)throws HibernateException { s87 a%
Criteria criteria = m\l51}xz
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detachedCriteria.getExecutableCriteria(session); {`tHJ|8
return bGhhh/n
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criteria.setProjection(Projections.rowCount :fl*w""V@
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()).uniqueResult(); o`oRG)QC
} (H'_KPK
}, true); 58qaA\iw
return count.intValue(); $_ST:h&C
}
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} unx;m$-c
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用户在web层构造查询条件detachedCriteria,和可选的 wa9'2a1?
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 @hE7r-}]
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PaginationSupport的实例ps。 dw|-=~
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ps.getItems()得到已分页好的结果集 Tb>IHoil
ps.getIndexes()得到分页索引的数组 }Z~pfm_S
ps.getTotalCount()得到总结果数 s@*,r@<
ps.getStartIndex()当前分页索引 s^{{@O.
ps.getNextIndex()下一页索引 JS<e`#c&
ps.getPreviousIndex()上一页索引 AJJ%gxqGq
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 "<g?x`iz
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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 =R"Eb1
i-K"9z|)
一下代码重构了。 0jip::x
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我把原本我的做法也提供出来供大家讨论吧: a:(: :m
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首先,为了实现分页查询,我封装了一个Page类: *Bb|N--jI
java代码: V'f&JQA
O>tC]sm%
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/*Created on 2005-4-14*/ mTI\,x%<OC
package org.flyware.util.page; W>t&N
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/** O=!)})YG
* @author Joa 5;sQ@
* /z.7:<gZ(
*/ r=iMo7q
publicclass Page { o\=i0HR9
'!r+Tz
/** imply if the page has previous page */ mV!
@oNCK
privateboolean hasPrePage; U||w6:W5
mv9E{m
/** imply if the page has next page */ 3_jCsX
privateboolean hasNextPage; &ttv4BC^r
+|}K5q \
/** the number of every page */ wn A%Nh7
privateint everyPage; &[2Ej|o
4,*^QK
/** the total page number */ ,SE$Rh
privateint totalPage; ;([tf;
#pm-nU%|_j
/** the number of current page */ X
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privateint currentPage; _WjETyh
[H
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/** the begin index of the records by the current VM V]TPks>
E23 Yk?"
query */ *|,ykb>
privateint beginIndex; $bi_i|?
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/** The default constructor */ v(Zi;?c
public Page(){ uZiY<(X
sG1]A:_<C
} cLyuCaH>c
*_).UAP.
/** construct the page by everyPage b#I*~
* @param everyPage :2UC{_
* */ /@nRL
public Page(int everyPage){ w[$nO#
this.everyPage = everyPage; Pdm6u73
} nwZr3r
h3d\MYO)B
/** The whole constructor */ rX>y>{w~
public Page(boolean hasPrePage, boolean hasNextPage, r(in]7
)x:j5{>(
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int everyPage, int totalPage, R,5$ 0_]|+
int currentPage, int beginIndex){ h^_taAdS`
this.hasPrePage = hasPrePage; }
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this.hasNextPage = hasNextPage; \Af|$9boHz
this.everyPage = everyPage; {|J2clL
this.totalPage = totalPage; S.F=$z.%
this.currentPage = currentPage; ?5YmE(v7
this.beginIndex = beginIndex; B%g :Z
} q}F%o0
j]l}K*8(
/** 'GzhZ`E6
* @return 6[|<
* Returns the beginIndex. aq,)6P`
*/ n`T[eb~
publicint getBeginIndex(){ U:4Og8
return beginIndex; w$;*~Qc
} Ce'2lo
8!%"/*P$
/** >.wd)
* @param beginIndex OZ14-}Lr5
* The beginIndex to set. S1= JdN
*/ kmr
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publicvoid setBeginIndex(int beginIndex){ >Wit"p
this.beginIndex = beginIndex; V\`="
} @gjdyz
t{s*3k/
/** Ru')X{]25
* @return Hh;6B!zb+
* Returns the currentPage. |j}F$*SE[
*/ u&_U
CJCf
publicint getCurrentPage(){ LLY;IUK!R
return currentPage; J+NK+,_*M
} EEZ2Gu6c
7-IeJ6,D
/** khIa9Nm
* @param currentPage N_Ld,J%g
* The currentPage to set. DF|lUO]:
*/ xy3%z
publicvoid setCurrentPage(int currentPage){ +vSE}
this.currentPage = currentPage; ;OJ0}\*iP8
} KmOa^vY1.T
_:p_#3s$
/** gbf=H8]
* @return l4reG:uYG
* Returns the everyPage. R,+(JgJ
*/ jF_I4H
publicint getEveryPage(){ y]4`d
return everyPage; /(pChY>
} * .VZ(wX
<1.mm_pw
/** %<|KJb4?
* @param everyPage {leG~[d
* The everyPage to set. 1W<_5 j_
*/ |bnjC $b *
publicvoid setEveryPage(int everyPage){ t+J6P)=
this.everyPage = everyPage; *v/*_6f*
} RcP5].^T
g"?D>}@=
/** |raQ]b@t&
* @return r!,V_a4n
* Returns the hasNextPage. R_n-&d'PP
*/ Z@/5~p
publicboolean getHasNextPage(){ nn%xN\~<
return hasNextPage; "]Td^Nxi
} kk+8NwM1
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/** ;}'<`(f&nX
* @param hasNextPage J3+8s[oJ>
* The hasNextPage to set. <t37DnCgI
*/ (SA*9%
publicvoid setHasNextPage(boolean hasNextPage){ ,`@|C
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this.hasNextPage = hasNextPage; j pv,0(
} uZI a-b
/z:K#
/** ,m]q+7E
* @return j~q`xv+R
* Returns the hasPrePage. F|Q#KwN
*/ G3?z.5,Q
publicboolean getHasPrePage(){ X&Lt?e,&
return hasPrePage; =LnAMl#9
} `,d7_#9'
j3&*wU_
/** =C)1NJx&~
* @param hasPrePage 3:
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* The hasPrePage to set. 0{F.DDiNT
*/ 'DQyB`V2y
publicvoid setHasPrePage(boolean hasPrePage){ E76:}(
this.hasPrePage = hasPrePage; 55p=veq \
} 063;D+
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/** _@2G]JD
* @return Returns the totalPage. W$S.?[X
* ,qB081hPG
*/ +)SX
publicint getTotalPage(){ qE{S'XyM,
return totalPage; 7l3q~ dQ
} Xk'.t|
5Y^YKV{
/** gzF&7trN
* @param totalPage *gVv74;;
* The totalPage to set. Lt_]3go
*/ }R$%MU5::
publicvoid setTotalPage(int totalPage){ -;}Wm[
this.totalPage = totalPage; T*m21<
} wn`budH?c8
4a-wGx#h
} ~\P.gSiz
m='OnTeOE
rNc>1}DDS
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qb&*,zN
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 GcuZPIN%D
yFG&Ir
个PageUtil,负责对Page对象进行构造: -|mABHjx*
java代码: o/R-1\Dn
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yrw!b\
/*Created on 2005-4-14*/ :[doYizk:
package org.flyware.util.page; k:sh:G+=$d
iYnt:C
import org.apache.commons.logging.Log; ?=/l@ d
import org.apache.commons.logging.LogFactory; O);V{1P
;XT$rtuX
/** sZc<h]L(g
* @author Joa _N6GV$Q
* "T PMSx&Ei
*/ R-ci?7d t3
publicclass PageUtil { 2.yzR DfZ
;I>`!|mT
privatestaticfinal Log logger = LogFactory.getLog WVZ\4y
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(PageUtil.class); sMZ \6
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/** Ae1},2py
* Use the origin page to create a new page OX91b<A
* @param page <T['J]k%
* @param totalRecords d<]/,BY'
* @return p~t$ll0s
*/ q_!3<.sf
publicstatic Page createPage(Page page, int $/Mk.(3'P
.$Y[>9
totalRecords){ @I%m}>4Jm
return createPage(page.getEveryPage(), @_;6L
@uc%]V<:k
page.getCurrentPage(), totalRecords); LTxOq|/Cq
} 1!~9%=%
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/** aD.A +e s
* the basic page utils not including exception kHJjdgV
m#uutomi0
handler #VLTx!5o
* @param everyPage f.!cR3XgV
* @param currentPage t ,0~5>5
* @param totalRecords , =#'?>Kq
* @return page nF=h|rN
*/ b( wiJ&t
publicstatic Page createPage(int everyPage, int m$]?Jq
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currentPage, int totalRecords){ Ax&+UxQ0|
everyPage = getEveryPage(everyPage); @hk~8y]rz
currentPage = getCurrentPage(currentPage); 905
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int beginIndex = getBeginIndex(everyPage, &",pPuq
7uYJ_R
currentPage); ^*Sb)tu\ W
int totalPage = getTotalPage(everyPage, < d?O#(
5K,Y6I&$SJ
totalRecords); m!g
f!
boolean hasNextPage = hasNextPage(currentPage, 1D 6iJ
YqYCW}$
totalPage); r.[9/'>
boolean hasPrePage = hasPrePage(currentPage); `w2hJP
8dP^zjPj
returnnew Page(hasPrePage, hasNextPage, <`BUk< uf#
everyPage, totalPage, _Y=>^K]9K
currentPage, ^MuO;<<,.
|[8&5[);
beginIndex); q45Hmz
} "+p_{J/P
'RXhE
privatestaticint getEveryPage(int everyPage){ phd,Jg[
return everyPage == 0 ? 10 : everyPage; +[ !K
} 0X.pI1jCO
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privatestaticint getCurrentPage(int currentPage){ "d9"Md0k
return currentPage == 0 ? 1 : currentPage; Iell`;
} 0KE+RzrB
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privatestaticint getBeginIndex(int everyPage, int n)gzHch
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currentPage){ UO>ADRs}
return(currentPage - 1) * everyPage; 5$/ED3mcK
} b|P[\9
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privatestaticint getTotalPage(int everyPage, int JdF;*`_7*
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totalRecords){ q{ i9VJ]
int totalPage = 0; /^SIJS@^`>
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if(totalRecords % everyPage == 0) )%I2#Q"Nt-
totalPage = totalRecords / everyPage; -A^18r
else mr&nB
totalPage = totalRecords / everyPage + 1 ; 8>%:MS"
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return totalPage; ]c4?-Vq%u
} u_shC"X:
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privatestaticboolean hasPrePage(int currentPage){ 0Z$=2c?xT
return currentPage == 1 ? false : true; d0vn/k2I
} 5)bf$?d
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privatestaticboolean hasNextPage(int currentPage, }8`W%_Yk
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int totalPage){ }86&?
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return currentPage == totalPage || totalPage == E{'{fo!#)
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0 ? false : true; &3~lZa;D
} _$g6Mj]1z
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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。 ?'SHt9b3|
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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 17kh6(X
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做法如下: B6qM0QW
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象
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的信息,和一个结果集List: ^jY/w>UdH
java代码: ;6+e !h'1
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/*Created on 2005-6-13*/ d6RO2^
package com.adt.bo; CcDmZ
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import java.util.List; MX*T.TG8
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import org.flyware.util.page.Page; ={'*C7K)oK
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/** Ebk9[=
* @author Joa /xS4>@hn
*/ pk>p|q
publicclass Result { nrFuhW\r
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private Page page; =@ SJyW
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private List content; ,q_'l?Pn
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/** S2APqRg*
* The default constructor E8gbm&x*
*/ !\'NBq,
public Result(){ W'98ues%
super(); xbTvv>'U
} _0GM!Cny
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/** DA9-F
* The constructor using fields 0aWy!d
* #.j[iN
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* @param page ( M$2CL
* @param content 2bnF#-(
*/ &gv{LJd5b
public Result(Page page, List content){ ]QqT.z%B
this.page = page; O,D/&0
this.content = content; &x
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} J$+K't5BZ
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/** <w1#3Mu'
* @return Returns the content.
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*/ ~#]$YoQ&O
publicList getContent(){ g!![%*'
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return content; I\y=uC
} .a@>1XO
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/** $D%[}[2
* @return Returns the page. fGf C[DuY
*/ MJ%gF=$X
public Page getPage(){ 2D vKW%;
return page; wOg?.6<Kxa
} j34L*?
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/** "Vw;y+F}
* @param content }i\U,mH0_&
* The content to set. .I1k+
*/ \J?l7mG
public void setContent(List content){ q\I2lZ
this.content = content; +<TnE+>j
} s0/[mAY
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/** [m+):q^
* @param page ^DaP^<V
* The page to set. H%&e[PU
*/ ]N#%exBVo
publicvoid setPage(Page page){ @TqqF:c7
this.page = page; EZw<)Q
} pI]tv@>:f
} xkPH_+4i8
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