Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 7>FXsUt_
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .Pb-{!$Ni
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 1(
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 lW+mH=
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分页支持类:
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java代码: U2q6^z4l
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package com.javaeye.common.util; *'%V}R[>
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import java.util.List; qJhsMo2IH
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publicclass PaginationSupport { f7Gn$E|/r;
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publicfinalstaticint PAGESIZE = 30; L, JQ\!c
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privateint pageSize = PAGESIZE; JMb_00r
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privateList items; p0+^wXi)
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privateint totalCount; SmRlZ!%e
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privateint[] indexes = newint[0]; 6Sr]<I +:
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privateint startIndex = 0; ,X4e?$7g
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public PaginationSupport(List items, int #36QO
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totalCount){ 34@ [ZKJ5
setPageSize(PAGESIZE); ]<;,HGO
setTotalCount(totalCount); );5o13h2
setItems(items); >4:d)
setStartIndex(0); ~>2uRjvkwB
} k3~9;Z
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public PaginationSupport(List items, int ;_<R +w3-
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totalCount, int startIndex){ {o=?@ $6C
setPageSize(PAGESIZE); NGx3f3 9
setTotalCount(totalCount); | f#wbw
setItems(items); 8nz({Mb9Z
setStartIndex(startIndex); Y
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} Q;M\fBQO}&
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public PaginationSupport(List items, int TT$Ao
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totalCount, int pageSize, int startIndex){ }F`|_8L*v)
setPageSize(pageSize); R.~[$G!
setTotalCount(totalCount); odRiCiMH
setItems(items); 6Rc=!_v^
setStartIndex(startIndex); !jCgTo
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} i?00!t
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publicList getItems(){ d2k-MZuT6
return items; K/Q"Z*
} gP^2GnjHL8
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publicvoid setItems(List items){ jLVJ+mu
this.items = items; P3M$&::D-
} vOQ%f?%G\
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publicint getPageSize(){ 91-bz^=xO
return pageSize; Up9{aX
} tFN >]`Z
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publicvoid setPageSize(int pageSize){ U|^xr~q!f-
this.pageSize = pageSize; $=aO*i
} @6u/)>rI
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publicint getTotalCount(){ mH*ldf;J;=
return totalCount; %,>z`D,Hg
} h
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publicvoid setTotalCount(int totalCount){ *$f=`sj
if(totalCount > 0){ D3pz69W
this.totalCount = totalCount; kfy!T rf
int count = totalCount / j\>LJai"
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pageSize; H4/wO
if(totalCount % pageSize > 0) @AyteHK
count++; \Mf>X\}
indexes = newint[count]; PEMkx"h +
for(int i = 0; i < count; i++){ YQVo7"`%
indexes = pageSize * G6SgVaM
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} tUn>=>cWP
}else{ Z!p\=M,%
this.totalCount = 0; "wUIsuG/p
} pYr"3BwG
} J<)qw
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publicint[] getIndexes(){ d{z[46>
return indexes; jhu
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} "c^! LV
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publicvoid setIndexes(int[] indexes){ QX,$JM3
this.indexes = indexes; kZ]H[\Fs
} =BJLj0=N
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publicint getStartIndex(){ j"W>fC/u
return startIndex; 4u{S?Ryy
} Y&|Z*s+
+}
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publicvoid setStartIndex(int startIndex){ bR\7j+*&
if(totalCount <= 0) XS<>0YM
this.startIndex = 0; $vn6%M[
elseif(startIndex >= totalCount) 3JazQU
this.startIndex = indexes 2e48L677-
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[indexes.length - 1]; A5l Cc
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elseif(startIndex < 0) ts]e M1;
this.startIndex = 0; FU`(mQ*Yd
else{ *$p*'vR
this.startIndex = indexes hmy%X`%j
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[startIndex / pageSize]; l#)X/(?;
} {UiSa'TR1b
} `oRyw6Sko
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publicint getNextIndex(){
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int nextIndex = getStartIndex() + ^FCXcn9
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pageSize; q'3{M]Tk
if(nextIndex >= totalCount) mz?<t/$U
return getStartIndex(); So%X(,
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else fN vQ.;
return nextIndex; )u?f| D
} 8R~<$xz
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publicint getPreviousIndex(){ U,GSWMI/K
int previousIndex = getStartIndex() - VRo&1:
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pageSize; bG;fwgAr
if(previousIndex < 0) -t-f&`S||
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else DE13x*2
return previousIndex; I8#2+$Be+@
} w,|@e_|J
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抽象业务类 _[:6.oNjIe
java代码: g)Z8WH$;H3
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/** `kKssU<
* Created on 2005-7-12 LKN7Lkl
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package com.javaeye.common.business; "M%R{pGA7
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import java.io.Serializable; ;`AB-
import java.util.List; U32$9"
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import org.hibernate.Criteria; e02Hf{eOfw
import org.hibernate.HibernateException; Ae5A@4
import org.hibernate.Session; 4KPnV+h"b
import org.hibernate.criterion.DetachedCriteria; 0d2P
import org.hibernate.criterion.Projections; (3e.q'
import U1\EwBK8*T
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org.springframework.orm.hibernate3.HibernateCallback; dJuy Jl$*
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org.springframework.orm.hibernate3.support.HibernateDaoS '1u?-2
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upport; ,%!m%+K9a
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import com.javaeye.common.util.PaginationSupport; N2:Hdu:
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public abstract class AbstractManager extends 14$%v;Su4
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HibernateDaoSupport { G1|1Z5r
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privateboolean cacheQueries = false; Lf_Y4a#
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privateString queryCacheRegion; ^^q&VL
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publicvoid setCacheQueries(boolean d+n2
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cacheQueries){ HDm]njF%qQ
this.cacheQueries = cacheQueries; Y e0,0Fpw
} lHiWzt
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publicvoid setQueryCacheRegion(String ~EtGR #
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queryCacheRegion){ iXWzIb}CJ-
this.queryCacheRegion = Om.%K>V
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queryCacheRegion; SIK:0>yK"
} :'h$]p%
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publicvoid save(finalObject entity){ Q#MB=:0{
getHibernateTemplate().save(entity); 4!sK>l!
} {S0-y
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publicvoid persist(finalObject entity){ CU=sQfE
getHibernateTemplate().save(entity); S1|5+PPs
} $f@YQN=
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publicvoid update(finalObject entity){ zJXK:/
getHibernateTemplate().update(entity); qV=:2m10x
} ):N#X<b':
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publicvoid delete(finalObject entity){ d&3"?2IQ
getHibernateTemplate().delete(entity); Q{~g<G
} y&(#C:N
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publicObject load(finalClass entity, '2X$.
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finalSerializable id){ [%k8l~ 6
return getHibernateTemplate().load si&du
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(entity, id); 5V 2ZAYV
} T]wC?gQG
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publicObject get(finalClass entity, )q x;/=D
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finalSerializable id){ ~q`f@I
return getHibernateTemplate().get ;*?>w|t}w
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(entity, id); cfmLErkp
} ,h=a+ja8
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publicList findAll(finalClass entity){ B}[CU='P*
return getHibernateTemplate().find("from =!-} q
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" + entity.getName()); $WIE`P%
} ]9_gbQ
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publicList findByNamedQuery(finalString +-tFg XG
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namedQuery){ 8SpG/gl"
return getHibernateTemplate Y. J!]|
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().findByNamedQuery(namedQuery); H!*ypJ
} U/'l "N[
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publicList findByNamedQuery(finalString query, et5lfj
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finalObject parameter){ mr7Oi `dE
return getHibernateTemplate D>k(#vYKB
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().findByNamedQuery(query, parameter); U4*u|A
} YE@yts
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publicList findByNamedQuery(finalString query, r 10VFaly
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finalObject[] parameters){ o2dO\$'
return getHibernateTemplate 7;+G)44
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().findByNamedQuery(query, parameters); UYxn?W.g
} SY|K9$M^
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publicList find(finalString query){ 'IY?=#xr'`
return getHibernateTemplate().find \ Bj{.jL
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(query); Ck#e54gJX
} T1q27I
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publicList find(finalString query, finalObject 2.WI".&y=
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parameter){ WOZuFS13
return getHibernateTemplate().find %|e)s_%XE
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(query, parameter); nrY)i_\
} mhVLlbY|t
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public PaginationSupport findPageByCriteria tC|?Kl7
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(final DetachedCriteria detachedCriteria){ 7d
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return findPageByCriteria d4ecF%R
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); A:Wr5`FJ
} 1J0gjO)AZ
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public PaginationSupport findPageByCriteria <Q(E {c3"
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(final DetachedCriteria detachedCriteria, finalint 8\68NG6o
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startIndex){ 6!>p<p"Ns
return findPageByCriteria XfE0P(sE
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(detachedCriteria, PaginationSupport.PAGESIZE, @\nQ{\^;
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startIndex); q83^?0WD
} ]=t}8H
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public PaginationSupport findPageByCriteria +rU{-`dy9'
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(final DetachedCriteria detachedCriteria, finalint 1N(#4mE=
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pageSize, .^*;hZ~4%
finalint startIndex){ B!pz0K*uG
return(PaginationSupport) zYV{ |Z
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getHibernateTemplate().execute(new HibernateCallback(){ mDz44XO
publicObject doInHibernate b9rQQS
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(Session session)throws HibernateException { &(,\~
Criteria criteria = 4/~x+tdc
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detachedCriteria.getExecutableCriteria(session); lv=q( &
int totalCount = ^85Eveu
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((Integer) criteria.setProjection(Projections.rowCount <qfAW?tF
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()).uniqueResult()).intValue(); l,l qhq\
criteria.setProjection \{`^Q+<
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(null); (Ff}Y.4
List items = g,]o+nT
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criteria.setFirstResult(startIndex).setMaxResults UB5H8&Rf!
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(pageSize).list(); Vm<_e
PaginationSupport ps = =V|jd'iwx
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new PaginationSupport(items, totalCount, pageSize, jUM'f24
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startIndex); m6[}KkW
return ps; ,V,mz?d^9
} ya1
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}, true); *VhEl7
} f~wON>$K
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public List findAllByCriteria(final s1Acl\l-uF
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DetachedCriteria detachedCriteria){ beo(7,=&
return(List) getHibernateTemplate :=y5713
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().execute(new HibernateCallback(){ 0&sa#g2
publicObject doInHibernate %?+vtX
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(Session session)throws HibernateException { H;4QuB'^
Criteria criteria = ,B'=$PO%
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detachedCriteria.getExecutableCriteria(session); nfF$h}<o+
return criteria.list(); \4wMv[;7
} #dae^UjM
}, true); 0#OyT'~V%
} <~5O-.G]
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public int getCountByCriteria(final NH|I>vyN
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DetachedCriteria detachedCriteria){ "W"^0To
Integer count = (Integer) vcdVck@
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getHibernateTemplate().execute(new HibernateCallback(){ 9{OO'at?
publicObject doInHibernate 6Yn>9llo}=
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(Session session)throws HibernateException { }qso} WI
Criteria criteria = ]Z5m_-I
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detachedCriteria.getExecutableCriteria(session); Cg]|x+
return KV$&qM.
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criteria.setProjection(Projections.rowCount <b
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()).uniqueResult(); =KHb0d |.
} QUW`Yc
}, true); boEQI=!j\+
return count.intValue(); =F$?`q`
} pgES)
} O8.xt|
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用户在web层构造查询条件detachedCriteria,和可选的 %]}JWXof
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 5zBA ]1PY
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PaginationSupport的实例ps。 Kg';[G\
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ps.getItems()得到已分页好的结果集 fX`u"`o5
ps.getIndexes()得到分页索引的数组 bUS:c
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ps.getTotalCount()得到总结果数 Oq~{HJ{
ps.getStartIndex()当前分页索引 Qw2`@P8W
ps.getNextIndex()下一页索引 Gw3+TvwU+Q
ps.getPreviousIndex()上一页索引 QIMd`c
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 (G>su
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 P}8hK
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一下代码重构了。 yZ6WbI8n
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我把原本我的做法也提供出来供大家讨论吧: UCcr>
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首先,为了实现分页查询,我封装了一个Page类: [T r7SU#x
java代码: "'[M~Js
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/*Created on 2005-4-14*/ zK~8@{l}_"
package org.flyware.util.page; ;GM`=M4
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/** C`[2B0
* @author Joa n~6$CQ5dF(
* u!D?^:u=)
*/ &m