Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 7S'3U}Y>VX
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 9OI&De5?=V
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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 BTi:Bcv k
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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 j6@5"wx
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分页支持类: )}`3haG
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java代码: Rd#V,[d
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package com.javaeye.common.util; e[`u:
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import java.util.List; 8~q%H1[I\N
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publicclass PaginationSupport { >'\cNM~nf
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publicfinalstaticint PAGESIZE = 30; $mS]K!\
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privateint pageSize = PAGESIZE; "otks\I<
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privateList items; ?uiQ'}
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privateint totalCount; *C>B-j$
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privateint[] indexes = newint[0]; \Pv_5LAo
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privateint startIndex = 0; !%pY)69gv
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public PaginationSupport(List items, int IO, kGUS
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totalCount){ ]yzqBbV
setPageSize(PAGESIZE); gc%aaYf>
setTotalCount(totalCount); 0H|U9
setItems(items); WGxe3(d
setStartIndex(0); GQZLOjsop
} v&.`^O3W
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public PaginationSupport(List items, int rkp 1tv
@ P[o
totalCount, int startIndex){ hJ)>BeH0
setPageSize(PAGESIZE); A
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setTotalCount(totalCount); ct,Iu+HJ
setItems(items); %]~XbO
setStartIndex(startIndex); @PYCl
} )+'De
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public PaginationSupport(List items, int urJ>dw?FI
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totalCount, int pageSize, int startIndex){ Nk~Xz
setPageSize(pageSize); *6Ojv-
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setTotalCount(totalCount); QQQ3U
setItems(items); D)yCuw{M:
setStartIndex(startIndex); H(eGqVAq,
} NT qtr="
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publicList getItems(){ rZ.,\ X_
return items; r*-e~
} L&C<-BA/
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publicvoid setItems(List items){ A5d(L4Q]a(
this.items = items; o6H\JCne
} ?DN4j!/$
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publicint getPageSize(){ .EOHkhn
return pageSize; a@1r3az
} FTB@70
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publicvoid setPageSize(int pageSize){ k\:f2%!!
this.pageSize = pageSize; ##%R|P3
} 1wx&/#a
}]-SAM
publicint getTotalCount(){ +y+-~;5iv
return totalCount; 6bL"Z OEu
} V;b^b5yZ>
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publicvoid setTotalCount(int totalCount){ 5W0'r'{
if(totalCount > 0){ W#pA W
this.totalCount = totalCount; Y,v8eOo45S
int count = totalCount / Jm%hb,
*{5L*\AZ
pageSize; bL=32YS
if(totalCount % pageSize > 0) w|6;Pf~1y)
count++; +6vm4(3?
indexes = newint[count]; =4RBHe8`
for(int i = 0; i < count; i++){ G\ twx ;
indexes = pageSize * 1dhp/Qh
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i; OL{U^uOhY
} O/gBBTB
}else{ .x__X3P>\
this.totalCount = 0; y{Wtm7fnA
} kcH?l
} ~jd:3ip+!
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publicint[] getIndexes(){ w%,Iy,G@
return indexes; {7`eR2#Wq
} s'LY)_n
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publicvoid setIndexes(int[] indexes){ =,D3e+P'
this.indexes = indexes; a#X[V5|6Q
} r4}:t$
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publicint getStartIndex(){ NpRT\cx3
return startIndex; ;9,<&fe
} ffGiNXCM
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publicvoid setStartIndex(int startIndex){ xz dqE
if(totalCount <= 0) imdfin?=
this.startIndex = 0; wi]|"\
elseif(startIndex >= totalCount) \WD}@6)
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this.startIndex = indexes zJWh
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[indexes.length - 1]; oDp!^G2A"
elseif(startIndex < 0) ukV1_QeN[
this.startIndex = 0; EfY|S3Av
else{ |$`LsA.
this.startIndex = indexes ^{8r(1,
X}`|"NIk.
[startIndex / pageSize]; t?9F2rh
} ysA~Nq@
} yG?,8!/]
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publicint getNextIndex(){ XW6Ewrm=vT
int nextIndex = getStartIndex() + sHO6y0P
5haJPWG|'
pageSize; G S-@drZp_
if(nextIndex >= totalCount) c@)k#/[[b
return getStartIndex(); Z^9;sb,x
else X
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return nextIndex; -~eNC^t;W
} +\G/j ]3f
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publicint getPreviousIndex(){ j,QeL
int previousIndex = getStartIndex() - w\KO1 Ob
g*Nc+W](P>
pageSize; )BudV zg
if(previousIndex < 0) ',nGH|K.
return0; A:F*Y%ZW
else zghUwW |K
return previousIndex; U/&!F
} 8D[P*?O
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} FQ>KbZh
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抽象业务类 fk,[`n+
java代码: J3cbDE%^m
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/** %,$/wh)<V
* Created on 2005-7-12 @ae;&
*/ cf?*6q?n
package com.javaeye.common.business; ZP5.?A-=C
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import java.io.Serializable; ae( o:G
import java.util.List; \Fj$^I>C
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import org.hibernate.Criteria; '}4LHB;:
import org.hibernate.HibernateException; Au,xIe!t
import org.hibernate.Session; J4!Om&\@
import org.hibernate.criterion.DetachedCriteria; L}lOA,EF
import org.hibernate.criterion.Projections; 1a4
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import TWkuR]5
!Vl>?U?AN
org.springframework.orm.hibernate3.HibernateCallback; z8FeL5.(
import O0Y/y2d
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org.springframework.orm.hibernate3.support.HibernateDaoS &NiDv
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upport; 0G?0 Bo
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import com.javaeye.common.util.PaginationSupport; LM}0QL
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public abstract class AbstractManager extends ;|&Ak_I2G
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HibernateDaoSupport { e8O[xM
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privateboolean cacheQueries = false; (cJb/|?3
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privateString queryCacheRegion; ZOvMA]Rf
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publicvoid setCacheQueries(boolean S*~v9+
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cacheQueries){ nV'~uu
this.cacheQueries = cacheQueries; -_BS!T%r
} (NrH)+)J!a
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publicvoid setQueryCacheRegion(String <Okk;rj2
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queryCacheRegion){ zS*GYE(l^
this.queryCacheRegion = 'zV/4iE=
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queryCacheRegion; )>08{7
} 1HK5OT&
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publicvoid save(finalObject entity){ H)aeSF5
getHibernateTemplate().save(entity); "Wd?U[[
} ;7CE{/Bq.p
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[(
publicvoid persist(finalObject entity){ m'H%O-h\
getHibernateTemplate().save(entity); Z!o&};_j
} sLh9=Kh`
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publicvoid update(finalObject entity){ Qm86!(eZ-
getHibernateTemplate().update(entity); xJ H]>#XJ
} EJ&[I%jU
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publicvoid delete(finalObject entity){ boAu
getHibernateTemplate().delete(entity); a!YpSFr
} =w='qjh
o#Q0J17i?
publicObject load(finalClass entity, &x$1hx'
9fR`un)f}
finalSerializable id){ !ckmNE0
return getHibernateTemplate().load 3x2*K_A5:Q
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(entity, id); NU>={9!
} A}K RXkB
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publicObject get(finalClass entity, k fS44NV
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finalSerializable id){ YI!ecx%/4
return getHibernateTemplate().get O^(ji8[l
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(entity, id); 6}bUX_!&s
} M_@%*y\o
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publicList findAll(finalClass entity){ yxq+<A4,a
return getHibernateTemplate().find("from NUH;\*]8s
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" + entity.getName()); P9(]9np,,
} PYWp2V/
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publicList findByNamedQuery(finalString %\OG#36
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namedQuery){ hxcRFqX"
return getHibernateTemplate et[n ;nl>V
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().findByNamedQuery(namedQuery); Nm;(M=
} y"4Nw]kU
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publicList findByNamedQuery(finalString query, 8%-+@\=
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finalObject parameter){ yk
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return getHibernateTemplate ]ADj9
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().findByNamedQuery(query, parameter); @2H"8KX
} 8}9B*m
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publicList findByNamedQuery(finalString query,
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l)@Zuh
finalObject[] parameters){ ')!+>b(P
return getHibernateTemplate !ho~@sc{W
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().findByNamedQuery(query, parameters); {Dv^j#
} 34k}7k~n
h>jLhj<07W
publicList find(finalString query){ n/ ]<Bc?
return getHibernateTemplate().find <HReh>)[
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(query); []opPQ
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} SRL`!
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publicList find(finalString query, finalObject `U-i{i
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parameter){ mc{gcZIm
return getHibernateTemplate().find (?luV#{5
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(query, parameter); kVu8/*Q
} L`$m<9w'
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public PaginationSupport findPageByCriteria 9wR-0E
)
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(final DetachedCriteria detachedCriteria){ !uIT5D
return findPageByCriteria dy>iIc>
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^\
(detachedCriteria, PaginationSupport.PAGESIZE, 0); D%PrwfR
} ;'^5$q
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public PaginationSupport findPageByCriteria o;.6Y `-fJ
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(final DetachedCriteria detachedCriteria, finalint -c%K_2`
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startIndex){ gY)NPi}!`
return findPageByCriteria '%JIc~LJ
4';~@IBf
(detachedCriteria, PaginationSupport.PAGESIZE, - v\n0Jt
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startIndex); i5oV,fiZo
} YA7h! %52)
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public PaginationSupport findPageByCriteria Tt,<@U[/}
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(final DetachedCriteria detachedCriteria, finalint Ww8C}2g3
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pageSize, {9yv3[f3
finalint startIndex){ I-@A{vvPK
return(PaginationSupport) Fpz)@0K;
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getHibernateTemplate().execute(new HibernateCallback(){ H9 d!-9I
publicObject doInHibernate &&(^;+
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(Session session)throws HibernateException { QKj8~l(
Criteria criteria = iX3Y:
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detachedCriteria.getExecutableCriteria(session); B@v\tpR
int totalCount = ~/R,oQ1!g}
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((Integer) criteria.setProjection(Projections.rowCount 3J^"$qfSn
'qhi8=*
()).uniqueResult()).intValue(); 8T:?C~"
criteria.setProjection \0K3TMl)J
{8'f>YP
(null); >8I?YT.
List items = Ts+S>$
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criteria.setFirstResult(startIndex).setMaxResults sj"zgE)
*]L(,_:"
(pageSize).list(); DEdJH4
PaginationSupport ps = 75u5zD
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new PaginationSupport(items, totalCount, pageSize, ("G
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startIndex); oWJ0>)
return ps; OGDCC/
} .ZV-]jgr
}, true); **oaR
} =/ b2e\
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public List findAllByCriteria(final w=dTa5
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DetachedCriteria detachedCriteria){ ^Po^Co
return(List) getHibernateTemplate rA=iBb3`
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().execute(new HibernateCallback(){ Yqpe2II7
publicObject doInHibernate B+8lp4V9%
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&\[
(Session session)throws HibernateException { NCid`a$
Criteria criteria = !Zr 9t|_
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detachedCriteria.getExecutableCriteria(session); "[Z'n9C
return criteria.list(); '@jP$6T&
} T:~c{S4&
}, true); W7\s=t\
} C(4r>TNm
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public int getCountByCriteria(final (IE\}QcK
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DetachedCriteria detachedCriteria){ X:0-FCT;\
Integer count = (Integer) Vo G`@^s
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getHibernateTemplate().execute(new HibernateCallback(){ E8`AU<
publicObject doInHibernate P+9%(S)L3
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(Session session)throws HibernateException { JBvMe H5
Criteria criteria = <w9<G
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detachedCriteria.getExecutableCriteria(session); R&!{3!V
return B%L dH
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criteria.setProjection(Projections.rowCount _e9S"``
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()).uniqueResult(); Ig.9:v`
} [f8mh88r
}, true); UHaY|I${U
return count.intValue(); +~ZFao qf
} #mFY?Zp)
} 0v"h/
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用户在web层构造查询条件detachedCriteria,和可选的 K'DRX85F
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 Wh7}G
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PaginationSupport的实例ps。 $z":E(oy
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ps.getItems()得到已分页好的结果集 w~lxWgaY7
ps.getIndexes()得到分页索引的数组 BQ
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ps.getTotalCount()得到总结果数 UbDRE[^P
ps.getStartIndex()当前分页索引 D'UYHc{
ps.getNextIndex()下一页索引 `yXJaTbo
ps.getPreviousIndex()上一页索引 O"c@x:i
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Scfk]DT
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 u,f$cR
7L"Pe'Hw
一下代码重构了。 ML= :&M!ao
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我把原本我的做法也提供出来供大家讨论吧: "A0J~YvYWJ
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首先,为了实现分页查询,我封装了一个Page类: _=s{,t
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java代码: 8`?vWJS
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/*Created on 2005-4-14*/ 5kju{2`GF
package org.flyware.util.page; /"LcW"2;N
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/** QaAWO
* @author Joa U`HSq=J
* J<'7z%2w
*/ MNzWTn@
publicclass Page { rcx'`CIJ
O*%@(w6
/** imply if the page has previous page */ l^,"^vz
privateboolean hasPrePage; NZh\{!
'K:zW>l
/** imply if the page has next page */ #rs]5tx([
privateboolean hasNextPage; N)tqjq
rgOc+[X
/** the number of every page */ +LEU|#
privateint everyPage; O 6}eV^y
6$k"B/k
/** the total page number */ p+pBk$4
privateint totalPage; =Co[pt
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/** the number of current page */ >#[u"CB
privateint currentPage; {0t-Q k
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/** the begin index of the records by the current ET[vJnReC
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query */ ~t ` uq
privateint beginIndex; l)^sE)
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/** The default constructor */ GqT0SP
public Page(){ x%WL!Lo
^G~C#t^
} [|)Eyd[G
6L)]nE0^
/** construct the page by everyPage 6_.K9;Gd
* @param everyPage PU\?eA
* */ E Pgn2[z
public Page(int everyPage){ 6hvmp
this.everyPage = everyPage; e/{1u$
} pFZ2(b&
@0mR_\u\
/** The whole constructor */ ~$PQ8[=
public Page(boolean hasPrePage, boolean hasNextPage, sr*3uI-)L
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int everyPage, int totalPage, 7P!Hryy
int currentPage, int beginIndex){ h ?Ni5
this.hasPrePage = hasPrePage; iO 9fg
this.hasNextPage = hasNextPage; _W3>Km-A=/
this.everyPage = everyPage; ;Az9p h
this.totalPage = totalPage; uzA_Zjx
this.currentPage = currentPage; \U0p?wdr:
this.beginIndex = beginIndex; f-O`Pp FQ
} "/O`#Do/
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/** BJ]4j-^o
* @return PS13h_j
* Returns the beginIndex. ~`<(T)rs
*/ +-VkRr#
publicint getBeginIndex(){ SS/9fT"[
return beginIndex; #:Tb(R
} xP3v65Q1
qNH=
W?T8.
/** ^D{!!)O
* @param beginIndex {5$.:Y
* The beginIndex to set. BaLvlB
*/ t81}jD
publicvoid setBeginIndex(int beginIndex){ SXA`o<Ma
this.beginIndex = beginIndex; [|XMR=\>
} *gJ:irah
\KGi54&Y
/** S:*.,zC
* @return
Y\Z.E;
* Returns the currentPage. " ^t3VjN
*/ +E{'A7im8=
publicint getCurrentPage(){ {GTOHJ2
return currentPage; 7B|ddi7Q>
} VdVUYp
*kliI]BF]
/** 3XCePA5z
* @param currentPage fG+/p 0sJ?
* The currentPage to set. .%.bIT
*/ g3}K
publicvoid setCurrentPage(int currentPage){ KfSI6
Y_
this.currentPage = currentPage; vS!%!-F
} ?!h
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/** 9K9{$jN~
* @return V<ZohB?y
* Returns the everyPage. u9TiEEof3
*/ ku@sQn
publicint getEveryPage(){ )2Ru}
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return everyPage; 0gR!W3dh
} w?r
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/** X9J&OQ[W
* @param everyPage 9^ DXw!
* The everyPage to set. S? -6hGA
j
*/ )_m#|U?Rex
publicvoid setEveryPage(int everyPage){ -3z$~
{
this.everyPage = everyPage; 7j9X<8*
} ?89K
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/** bJ~@
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* @return 8lI'[Y?3.
* Returns the hasNextPage. &<oZl.T
*/ 8?YWE62
publicboolean getHasNextPage(){ i`FskEoijq
return hasNextPage; $KmhG1*s
} 6lp.0B
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/** d0b`qk @4
* @param hasNextPage %, Pwo{SH
* The hasNextPage to set. S)$)AN<O
*/ Cwb}$=p'
publicvoid setHasNextPage(boolean hasNextPage){ ?qdZ]M4e
this.hasNextPage = hasNextPage; ;Q1/53Y<
} L\CufAN
n1"QHA
/** H{XD>q.
* @return @TvoCDeI
* Returns the hasPrePage. <9BM%
*/ Po~u-5
publicboolean getHasPrePage(){ (_9cL,v
return hasPrePage; `T-lBwH
} }'"4q
+Kw&XRAd
/** KMhEU**
* @param hasPrePage _#kjiJj*
* The hasPrePage to set. uoryxKRjc~
*/ 5ree3 quh
publicvoid setHasPrePage(boolean hasPrePage){ 1]yjhw9g
this.hasPrePage = hasPrePage; HxH.=M8S_
} zRz7*o&l
*<5zMSZO
/** P+hp'YK1
* @return Returns the totalPage. g4`)n`
* R3[H#*gF<
*/ [h3y8O
publicint getTotalPage(){ y5v}EX`m&
return totalPage; r=`]L-}V
} OE"r=is
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r(
/** Gp PlO]
* @param totalPage bM9:h
* The totalPage to set. ToNRY<!
*/ --32kuF&(
publicvoid setTotalPage(int totalPage){ '/h~O@Rw
this.totalPage = totalPage; 9T#JlV
} !OO{qw(*g
]rhxB4*1
} us:V\V
?
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p{sbf;-x}
i;yr=S,a0/
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 ZgXn8O[a
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个PageUtil,负责对Page对象进行构造: LvtZZX6!
java代码: v+3-o/G7
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8
/*Created on 2005-4-14*/ )R QX1("O
package org.flyware.util.page; X~H~k1
$?dAO}f3O)
import org.apache.commons.logging.Log; U;QN+fF]u
import org.apache.commons.logging.LogFactory; gEE6O%]g
'+
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/** p
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* @author Joa (IrX\Y
* \[-z4Fxg|'
*/ #*g .hL<
publicclass PageUtil { =Wl*.%1 b
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privatestaticfinal Log logger = LogFactory.getLog ${/"u3a_
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(PageUtil.class); s 4Mi9h_
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/** iz2I4 _N
* Use the origin page to create a new page h%hE$2
* @param page +dkbt%7M
* @param totalRecords /$IF!q+C
* @return +18)e;
*/ <Wn"_Ud=
publicstatic Page createPage(Page page, int )6S;w7
x bG'![OX
totalRecords){ K|H&x"t
return createPage(page.getEveryPage(), jJpSn[{
%HRFH
page.getCurrentPage(), totalRecords); :qx>P_&y}z
} (okCZ-_Jn
xLE+"6;W
/** OFJ
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* the basic page utils not including exception I6]|dA3G
,RkL|'1l
handler $RQ7rL3g{
* @param everyPage ^6?NYHMr=
* @param currentPage + *YGsM`E9
* @param totalRecords L`i#yXR
* @return page +[ _)i9a
*/ s*g yk
publicstatic Page createPage(int everyPage, int 23/!k}G"
8ycmvpJ
currentPage, int totalRecords){ TtL2}Wdd.%
everyPage = getEveryPage(everyPage); ]Q\Ogfjp
currentPage = getCurrentPage(currentPage); 0Fw0#eE
int beginIndex = getBeginIndex(everyPage, Nxu10
q8:Z.<%8
currentPage); S7Xr~5>X
int totalPage = getTotalPage(everyPage, 2Yx6.e<
}2Lh'0 xY
totalRecords); U*ZP>Vv
boolean hasNextPage = hasNextPage(currentPage, '3>kD H+
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totalPage); TEZ^Ia
boolean hasPrePage = hasPrePage(currentPage); 2,nKbE9*
=*.Nt*;;
returnnew Page(hasPrePage, hasNextPage, d"nz/$
everyPage, totalPage, @GGzah#
currentPage, }DTpl?l
ce{GpmW
beginIndex); 4#uWj?u
} ,\;;1Kq
,ZcW+!
privatestaticint getEveryPage(int everyPage){ Y[gj2vNe4g
return everyPage == 0 ? 10 : everyPage; p6[a"~y
} omM*h{z$$
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privatestaticint getCurrentPage(int currentPage){ b .k
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return currentPage == 0 ? 1 : currentPage; Q>nq~#3?
} YzU(U_g$
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privatestaticint getBeginIndex(int everyPage, int TX]4Y953D
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currentPage){ n.C.th
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return(currentPage - 1) * everyPage; @FL?,_,Y{
} 1TfK"\
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privatestaticint getTotalPage(int everyPage, int ~$>l@> xX
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totalRecords){ ~oI7TP
int totalPage = 0; W-%oj.BMA
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if(totalRecords % everyPage == 0) _3h(R`VdWO
totalPage = totalRecords / everyPage; ^~(vP:
else s
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totalPage = totalRecords / everyPage + 1 ; (7x5
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return totalPage; } ab@Nd$
} `CW8Wj
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privatestaticboolean hasPrePage(int currentPage){ Mn $TWhg'
return currentPage == 1 ? false : true; XJsHy_6
} qSj2=dlW
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privatestaticboolean hasNextPage(int currentPage, }pj>BK>
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int totalPage){ =6imrRaaV
return currentPage == totalPage || totalPage == KDgJ~T
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0 ? false : true; D61CO-E(D
} 0 V*Di2
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} XodA(73`i
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 +:?-Xd:p
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 .MMFN}1O
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做法如下: ! lgsV..R
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 x;S v&
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的信息,和一个结果集List: *qYcb}
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java代码: 4.7OX&L'G
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/*Created on 2005-6-13*/ ge:UliHJ
package com.adt.bo; G`PSb<h\oc
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import java.util.List; m `~/]QQ
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import org.flyware.util.page.Page; 1@RctI_}
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/** +r *f2\S
* @author Joa #ebT$hf30
*/ 2<)63[YO
publicclass Result { &\4AvaeA8y
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private Page page; a h>k=t8(
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private List content; (o)nN8
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/** D{I^_~-\5
* The default constructor &N GYV
*/ ;!DUN zl
public Result(){ !/ TeTmo
super(); /
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} >|WNsjkU%
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/** 1s8 v E
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* The constructor using fields JDfkm+}uY
* 'A
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* @param page gN$.2+:
* @param content D oX!P|*
*/ f;`pj`-k%
public Result(Page page, List content){ 8hba3L_Z
this.page = page; |8PUmax
this.content = content; )Q9m,/F
} @B
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/** ~4y&]:I
* @return Returns the content. /+pbO-r W*
*/ v+f:VA
publicList getContent(){ K)~ m{
return content; Ke '?
} 35B G&;C
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/** L22GOa0
* @return Returns the page. 2ikY.Xi6
*/ ,S
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public Page getPage(){ /2pf*\u
return page; "-GjwB
} \?7)oFNz
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/** #\KSv
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* @param content 5A /8G}'XZ
* The content to set. IXNcn@tN
*/ a5ZU"6Hi
public void setContent(List content){ 7yo/sb9h
this.content = content; EM!# FJh
} RQ}(}|1+\
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/** La9v97H:
* @param page QLrFAV
* The page to set. Dw{rjK\TT'
*/ ~6m-2-14q
publicvoid setPage(Page page){ CAyV#7[0
this.page = page; Bf!i(gM
} Dz/I"bZLC
} S6CM/
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N|hNh$J[
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S!Ue+jW
2. 编写业务逻辑接口,并实现它(UserManager, W$LaXytmak
S6-)N(3|
UserManagerImpl) Li~(kw3
java代码: EeGP E
#~?Q?"
&os9K)
/*Created on 2005-7-15*/ Uf)?sz
package com.adt.service; !Cxo4Twg
w"d~R
import net.sf.hibernate.HibernateException; e^kccz2f
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import org.flyware.util.page.Page; ?:l3O_U5
-y]\;pbZ0
import com.adt.bo.Result; Ug>yTc_(7
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/** xLX<