Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 hB<.u
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 nZQZ!Vfj
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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 ?|^1-5l3
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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 (J Fa
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分页支持类: (FMG W
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java代码: nngL,-v#F
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package com.javaeye.common.util; Xu HJy
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import java.util.List; /eR @&!D '
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publicclass PaginationSupport { ~;m~)D
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publicfinalstaticint PAGESIZE = 30; _?Jm.nT
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privateint pageSize = PAGESIZE; NLb/Bja
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privateList items; z[qM2
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privateint totalCount; CNcH)2Mk
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privateint[] indexes = newint[0]; m{Q{ qJ5>
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privateint startIndex = 0; R|NmkqTK~(
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public PaginationSupport(List items, int 2~h)'n7Mw
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totalCount){ }9P)<[>
setPageSize(PAGESIZE); U$VTk
setTotalCount(totalCount); ;?inf`t
setItems(items); |c 8p{)
setStartIndex(0); jopC\Z
} \/K>Iv'$
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public PaginationSupport(List items, int 9FK:lFGD
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totalCount, int startIndex){ ,O
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setPageSize(PAGESIZE); [W{`L_"
setTotalCount(totalCount); 6mdJ
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setItems(items); Mw'd<{
setStartIndex(startIndex); :g<dwuVO
} :Np&G4IM>
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public PaginationSupport(List items, int XfbkK )d
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totalCount, int pageSize, int startIndex){ tGmyTBgx
setPageSize(pageSize); L/nz95
setTotalCount(totalCount); ;p\rgam
setItems(items); L1)?5D
setStartIndex(startIndex); m}Tu^dy
} D>*%zz|
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publicList getItems(){ m
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return items; ew?UHV
} S2jo@bp!
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publicvoid setItems(List items){ C
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this.items = items; *+p'CfsSka
} Iobo5B
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publicint getPageSize(){ C?x
return pageSize; uc7np]Z
} 5W<BEcV\
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publicvoid setPageSize(int pageSize){ ={maCYlE.
this.pageSize = pageSize; =Z-.4\ 3
} !JYDg
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publicint getTotalCount(){ qd{|"(9B
return totalCount; &Vgjd>
} 2
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publicvoid setTotalCount(int totalCount){ f "Iv
if(totalCount > 0){ OgH Wmb
this.totalCount = totalCount; d\Dxmb]o
int count = totalCount / 6oUT+^z#
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pageSize;
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if(totalCount % pageSize > 0) ^Gs!" Y
count++; kf5921(P
indexes = newint[count]; ;ejC:3yO
for(int i = 0; i < count; i++){ yx/:<^"-$
indexes = pageSize * NmtBn^t
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} ]Dx?HBM"DC
}else{ u4+VG5.rhT
this.totalCount = 0; cVulJ6
} wRie{Vk
} /[EI0~P
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publicint[] getIndexes(){ .Uih|h
return indexes; n }MG
} ,9+@\
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publicvoid setIndexes(int[] indexes){ UhEJznfi
this.indexes = indexes; #lVVSrF,-
} OH=Ffy F,
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publicint getStartIndex(){ D]oS R7h
return startIndex; 54}s:[O
} .-Ao%A W
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publicvoid setStartIndex(int startIndex){ ^jCkM29eu
if(totalCount <= 0) 8:M~m]Z+|
this.startIndex = 0; _bMs~%?~/
elseif(startIndex >= totalCount) UJ6WrO5#kB
this.startIndex = indexes NWNgh/9?
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[indexes.length - 1]; g?@(+\W
elseif(startIndex < 0) Z.R^@@RqJ
this.startIndex = 0; }){hQt7
else{
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this.startIndex = indexes H9jj**W ;$
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[startIndex / pageSize]; X)uT-F y
} DDkOg]
} MCYrsgg}
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publicint getNextIndex(){ mfx'Yw*{
int nextIndex = getStartIndex() + sk],_ l<
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pageSize; +pjD{S~Y
if(nextIndex >= totalCount) ,g\.C+.S
return getStartIndex(); ,%ajIs"Gi
else l{y~N
return nextIndex; ~sA}.7
} ]q?<fEG2<
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publicint getPreviousIndex(){ OK2wxf
int previousIndex = getStartIndex() - e| kYu[^
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pageSize; a{u)~:/G
if(previousIndex < 0) w93yhV?
return0; DsFrA]
else =n#xnZ3
return previousIndex; mY%PG
} @P@t/
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} ;#j/F]xG
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抽象业务类 +$<m ;@mZ
java代码: *?i~AXJm
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/** _|s{G
* Created on 2005-7-12 2KPXRK
*/ 8ztY_"]3p
package com.javaeye.common.business; #U6Wv1H{Lp
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import java.io.Serializable; *.~M#M 9c
import java.util.List; :z^c<KFX
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import org.hibernate.Criteria; Y#rao:I
import org.hibernate.HibernateException; m$$U%=r>@
import org.hibernate.Session; naAZR*(A
import org.hibernate.criterion.DetachedCriteria; 2j_L
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import org.hibernate.criterion.Projections; 7qnw.7p
import Xt$?Kx_,
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org.springframework.orm.hibernate3.HibernateCallback; O"{NHNG\oT
import pG|DT ?
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org.springframework.orm.hibernate3.support.HibernateDaoS aFl(K\
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upport; &{7%VsTB
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import com.javaeye.common.util.PaginationSupport; [z Y9"B<3
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public abstract class AbstractManager extends Lo !kv*
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HibernateDaoSupport { o 0fsM;K
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privateboolean cacheQueries = false; q`qbaX\J3
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privateString queryCacheRegion; >pn?~
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publicvoid setCacheQueries(boolean .+ _x|?'
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cacheQueries){ %)]{*#N4
this.cacheQueries = cacheQueries; [dUW3}APV
} H'2pmwk
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publicvoid setQueryCacheRegion(String r_Xk:
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queryCacheRegion){ fkYa
this.queryCacheRegion = y5oiH
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queryCacheRegion; C/lpSe
} j1>1vD-`T
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publicvoid save(finalObject entity){ ?HU(0Vgn'
getHibernateTemplate().save(entity); ?n[+0a:8E
} Y2Y/laD
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publicvoid persist(finalObject entity){ q?JP\_o:
getHibernateTemplate().save(entity); ;B!&( 50e
} >a]{q^0
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publicvoid update(finalObject entity){ %m{h1UQQ+
getHibernateTemplate().update(entity); I)n%aT fo8
} !WAbO(l
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publicvoid delete(finalObject entity){ 3M/kfy
getHibernateTemplate().delete(entity); $S3C_..
} _AK-AY
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publicObject load(finalClass entity, UDGVq S!,E
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finalSerializable id){ 7)<&,BWc
return getHibernateTemplate().load
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(entity, id); v-g2k_o|
} lP0'Zg(
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publicObject get(finalClass entity, 1XL^Zhr
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finalSerializable id){ ?3"lI,!0
return getHibernateTemplate().get rVkRU5
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(entity, id); Np+<)q2
} THkg,*;:
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publicList findAll(finalClass entity){ -I'#G D>
return getHibernateTemplate().find("from j%Usui<DL
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" + entity.getName()); g \&Z_
} p~BEz?e
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publicList findByNamedQuery(finalString h 5<46!P
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namedQuery){ ={B%qq
return getHibernateTemplate <V>]-bl/
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().findByNamedQuery(namedQuery); Wv8?G~>
} Y'mtMLfMc
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publicList findByNamedQuery(finalString query, ,F!zZNW9
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finalObject parameter){ yxik`vmH
return getHibernateTemplate U]ynnw4
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().findByNamedQuery(query, parameter); lvY[E9I0
} Uyj6Ij_Pj)
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publicList findByNamedQuery(finalString query, <Y:{>=
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finalObject[] parameters){ gE\&[;)DB
return getHibernateTemplate `-/-(v+ i
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().findByNamedQuery(query, parameters); Uc^e Ia@
} n
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publicList find(finalString query){ ";yey ]
return getHibernateTemplate().find u0zF::
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(query); T\?$7$/V
} .o8Sy2PaV
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publicList find(finalString query, finalObject \|&KD
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parameter){ /W9(}Id6
return getHibernateTemplate().find R-LMV
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(query, parameter); q=(%
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} )0+6^[Tqq
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public PaginationSupport findPageByCriteria FkE)~g
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(final DetachedCriteria detachedCriteria){ /oOZ>B%1s
return findPageByCriteria V^Y'!w\LGI
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); UE8j8U'L
} ~I6N6T Z
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public PaginationSupport findPageByCriteria ,_iq$I;
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(final DetachedCriteria detachedCriteria, finalint HxSq&j*F
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startIndex){ ];xDXQd
return findPageByCriteria qYoB;gp
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(detachedCriteria, PaginationSupport.PAGESIZE, bd]9kRq1K
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startIndex); UodBK7y
} !7Eodq-0
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public PaginationSupport findPageByCriteria $vrkxn
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(final DetachedCriteria detachedCriteria, finalint -M/j&<;LW
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pageSize, 3xg9D.A
finalint startIndex){ qv& Bai[
return(PaginationSupport) *5IB@^<
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getHibernateTemplate().execute(new HibernateCallback(){ ])}a^]0q
publicObject doInHibernate B*Q 9g r
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(Session session)throws HibernateException { H2H`7 +I,
Criteria criteria = 2ah%,o
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detachedCriteria.getExecutableCriteria(session); 8~tX>q<@q
int totalCount = U%q-#^A
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((Integer) criteria.setProjection(Projections.rowCount }}"pQ!Z
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()).uniqueResult()).intValue(); G4uG"
criteria.setProjection I`zd:o]
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(null); >`r3@|UY
List items = 0:f]&Ng
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criteria.setFirstResult(startIndex).setMaxResults 6<2H 7'
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(pageSize).list(); =:aJZ[UU<2
PaginationSupport ps = w
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new PaginationSupport(items, totalCount, pageSize, ak7kb7 5o
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startIndex); jUE gu
return ps; ki?h7
} !!A0K"h
}, true); #F`A(n
} Dn6U8s&
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public List findAllByCriteria(final o:D,,MkSw
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DetachedCriteria detachedCriteria){ J91[w?,
return(List) getHibernateTemplate E7t;p)x
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().execute(new HibernateCallback(){ ; h\T7pwwb
publicObject doInHibernate ;xZjt4M1
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(Session session)throws HibernateException { =}vT>b
Criteria criteria = _]-4d_&3(
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detachedCriteria.getExecutableCriteria(session); W7^[W.
return criteria.list(); Xx"<^FS[zC
} G@.MP|
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}, true); $#q`Y+;L2
} #L~i|(=U5
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public int getCountByCriteria(final IdQ./@?
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DetachedCriteria detachedCriteria){ b~J)LXj]w
Integer count = (Integer) &}r"Z?f)
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getHibernateTemplate().execute(new HibernateCallback(){ @eJCr)#}
publicObject doInHibernate N7?B"p/
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(Session session)throws HibernateException { j-":>}oW2.
Criteria criteria = yd).}@
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detachedCriteria.getExecutableCriteria(session); 8.i4QaU
return uMJ\
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criteria.setProjection(Projections.rowCount Ot2o=^Ng
} o%^
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()).uniqueResult(); Y !?'[t
} W6&vyOc
}, true); G3~`]qf
return count.intValue(); [ QiG0D_'=
} b6bs .
} yO q@w!xz
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用户在web层构造查询条件detachedCriteria,和可选的 5o#JHD
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 `7CK;NeT
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PaginationSupport的实例ps。 0B}4$STOo[
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ps.getItems()得到已分页好的结果集 *'?7OL
ps.getIndexes()得到分页索引的数组
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ps.getTotalCount()得到总结果数 FJ:^pROpm
ps.getStartIndex()当前分页索引 w&q[%(G_
ps.getNextIndex()下一页索引 !sb r!Qt
ps.getPreviousIndex()上一页索引 WMSJU/-P
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 xu2KEwgb
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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 Zh=arlk
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一下代码重构了。 MUO<o
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我把原本我的做法也提供出来供大家讨论吧: o*S_"
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首先,为了实现分页查询,我封装了一个Page类: $ik*!om5
java代码: P {TJ$
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/*Created on 2005-4-14*/ `(e :H
package org.flyware.util.page; K^Awf6%
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/** Cn{Hk)6
* @author Joa '5e,@t%y
* c3$T3Lu1
*/ mj~:MCC
publicclass Page { VdLoi\-/L
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/** imply if the page has previous page */ "Ms;sdjg}&
privateboolean hasPrePage; W>K^55'
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/** imply if the page has next page */ "
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privateboolean hasNextPage; J2YQdCL
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/** the number of every page */ 3k Ci5C
privateint everyPage; %#HU~X:
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/** the total page number */ 5E]t4"
privateint totalPage; C($l'jd&
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/** the number of current page */ $><