Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 "gN* J)!x
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Z"~6yF
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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 ys[i`~$
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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 b6!Q!:GO&
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分页支持类: M,\|V3s
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java代码: _UBJPb@=U
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package com.javaeye.common.util; bpF@}#fT
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import java.util.List; /[|}rqX(
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publicclass PaginationSupport { UQ$\
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publicfinalstaticint PAGESIZE = 30; oX2DFgz
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privateint pageSize = PAGESIZE; KSgQ:_u4}
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privateList items; [2QY
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privateint totalCount; P96Cw~<Q?
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privateint[] indexes = newint[0]; t|#NMRz
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privateint startIndex = 0; EAC(^+15K
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public PaginationSupport(List items, int yo?g"vbE
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totalCount){ 0K$WSGB?6j
setPageSize(PAGESIZE); UYcyk
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setTotalCount(totalCount); 2yJ7]+Jd7Y
setItems(items); KtfkE\KP
setStartIndex(0); q-3J.VLJ5H
} nz&b5Xb2
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public PaginationSupport(List items, int lrmt)BLoh
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totalCount, int startIndex){ KMpDlit
setPageSize(PAGESIZE); %qNj{<&
setTotalCount(totalCount);
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setItems(items); ui.QYAYaV
setStartIndex(startIndex); p-T~x$"c|
} m0BG9~p|
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public PaginationSupport(List items, int U5On-T5
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totalCount, int pageSize, int startIndex){ ^B<PD]
setPageSize(pageSize); }j5R@I6P
setTotalCount(totalCount); /\ ,_P
setItems(items); Io,/ +#|
setStartIndex(startIndex); kH>vD =q>
} K)9j
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publicList getItems(){ +Dq|l}
return items; VGTeuu5i
} HC9vc,Fp
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publicvoid setItems(List items){ w
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this.items = items; k Z+ q
} 45r]wT(C
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publicint getPageSize(){ Xa{~a3Wy
return pageSize; =9DhO7I'
} v|4STR
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publicvoid setPageSize(int pageSize){ ?8wwd!)x%
this.pageSize = pageSize; Q8;x9o@p
}
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publicint getTotalCount(){ (opROsFh
return totalCount; .KiPNTh'
} B%%.@[o,
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publicvoid setTotalCount(int totalCount){ 3D?IG\3
if(totalCount > 0){ c]s(u+i
this.totalCount = totalCount; c ,h.`~{
int count = totalCount / O:`GL1{ve?
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pageSize; E(aX4^]g
if(totalCount % pageSize > 0) =1{H
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count++; 7X9+Qj;
indexes = newint[count]; $I)Tk`=
for(int i = 0; i < count; i++){ ;1{iF2jZ:
indexes = pageSize * @ 7Q*h
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} 4cXAT9
}else{ b[J-ja.
this.totalCount = 0; }|Hw0z P.
} 8Ehy9<
} G?Qe"4
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publicint[] getIndexes(){ [ -9)T
return indexes; V9 +xL 1U#
} (ZE%tbm2
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publicvoid setIndexes(int[] indexes){ -,K*~z.l
this.indexes = indexes; ,GdxUld
} E<D+)A
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publicint getStartIndex(){ a-T*'F
return startIndex; O tXw/
} [ E$$nNs
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publicvoid setStartIndex(int startIndex){ FSW3'
if(totalCount <= 0) o-\ok|,)#j
this.startIndex = 0; SKB@
elseif(startIndex >= totalCount) 8eOl@}bV
this.startIndex = indexes 'sm[CNzS
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[indexes.length - 1]; L0X&03e=e:
elseif(startIndex < 0) ]uBT &
this.startIndex = 0; !pd7@FwC
else{ X0^zw^2W
this.startIndex = indexes X)FL[RO%q
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[startIndex / pageSize]; 6obQ9L c
} 7j@^+rkr3f
} G*)s%2c>h
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publicint getNextIndex(){ *)j@G:
int nextIndex = getStartIndex() + (/T+Wpy?
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pageSize; )x$!K[=
if(nextIndex >= totalCount) ,3w I~j=
return getStartIndex(); z7'n, [
else ]sX7%3P
return nextIndex; a='IT 5
} z{_mEE49
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publicint getPreviousIndex(){
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int previousIndex = getStartIndex() - 7ZF}0K$^B
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pageSize; Y
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if(previousIndex < 0) 2B6^]pSk
return0; EG F:xl
else aj&\CJ
return previousIndex; @;||peU
} `^O'V}T
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} y\[L?Rmd
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抽象业务类 l0gH(28K
java代码: R!sNg
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/** &(lMm )
* Created on 2005-7-12 cNdu.c[@
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package com.javaeye.common.business; IetCMp
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import java.io.Serializable; ceqFQ
import java.util.List; E2>im>p
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import org.hibernate.Criteria; 3wV86tH%
import org.hibernate.HibernateException; B#J{ F
import org.hibernate.Session; $`E4m8fX
import org.hibernate.criterion.DetachedCriteria; V78Mq:7d
import org.hibernate.criterion.Projections; x*:n4FZ7b
import ri_P;#lz
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org.springframework.orm.hibernate3.HibernateCallback; Xfj)gPt}
import kBrvl^D{5
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org.springframework.orm.hibernate3.support.HibernateDaoS #o"tMh!f
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upport; .=?Sz*3
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import com.javaeye.common.util.PaginationSupport; D[V`^CTu
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public abstract class AbstractManager extends 0 9tikj1
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HibernateDaoSupport { )m|C8[ u
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privateboolean cacheQueries = false; Gj6<s./
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privateString queryCacheRegion; 3QH(4N
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publicvoid setCacheQueries(boolean n1_ %Td
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cacheQueries){ STv(kQs
this.cacheQueries = cacheQueries; TV<Aj"xw
} pH^ z
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publicvoid setQueryCacheRegion(String L%f-L.9`u
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queryCacheRegion){ 6tX.(/+L
this.queryCacheRegion = QI.t&sCh5
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queryCacheRegion; yj>){NcX
} e,^pMg~
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publicvoid save(finalObject entity){ 6{L F-`S%
getHibernateTemplate().save(entity); V!mWn|lf
} "@(58nk
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publicvoid persist(finalObject entity){ OthG7+eF
getHibernateTemplate().save(entity); Ks|gL#)*Ku
} -P2 @mx%
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publicvoid update(finalObject entity){ NOV.Bs{
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getHibernateTemplate().update(entity); EVWA\RO'\
} {K+.A 9!
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publicvoid delete(finalObject entity){ }&mj.hGv
getHibernateTemplate().delete(entity); )ukF3;Gt
} rYbCOazr
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publicObject load(finalClass entity, (yfXMp,x
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finalSerializable id){ Kf|0*c
return getHibernateTemplate().load (s&ORoVGn
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(entity, id); hUBF/4s\
} |%-YuD
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publicObject get(finalClass entity, y!F:m=x<
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finalSerializable id){ :u
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return getHibernateTemplate().get )TM!ms+K
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(entity, id); $]Jf0_
} kw3+>{\
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publicList findAll(finalClass entity){ {QMN=O&n
return getHibernateTemplate().find("from O
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} TFYw
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publicList findByNamedQuery(finalString S3QaYq"v
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namedQuery){ rJX\6{V!_
return getHibernateTemplate 'bl%Y).9w
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().findByNamedQuery(namedQuery); <M=';h^w2
} GZ
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publicList findByNamedQuery(finalString query, W5|j1He&
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finalObject parameter){ +eC3?B8rN
return getHibernateTemplate uC)Zs, _5
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().findByNamedQuery(query, parameter); mLQUcYfR
} M= atls
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publicList findByNamedQuery(finalString query, Xty#vI
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finalObject[] parameters){ %iX/y
return getHibernateTemplate w?*jdwh,'
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().findByNamedQuery(query, parameters); J,9%%S8/C
} ;|;iCaD a+
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publicList find(finalString query){ wz h.$?~
return getHibernateTemplate().find fwy"w
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(query); bK?MT]%}r
} *{Yh6{
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publicList find(finalString query, finalObject Et.j1M|g
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parameter){ q#jEv- j.
return getHibernateTemplate().find /e .D/;]
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(query, parameter); h^Qh9G0dn
} Nkx0CG*
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public PaginationSupport findPageByCriteria _Yy:s2I8B
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(final DetachedCriteria detachedCriteria){ v[smQO
return findPageByCriteria VE*j*U
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); V!W1fb7V
} (2d3jQN`
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public PaginationSupport findPageByCriteria J$rJd9t
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(final DetachedCriteria detachedCriteria, finalint R2CQXhiJ
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startIndex){ f0u56I9
return findPageByCriteria &u=8r*
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(detachedCriteria, PaginationSupport.PAGESIZE, SD^E7W$?
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startIndex); z,avQR&
} /,LfA2^_j{
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public PaginationSupport findPageByCriteria `Klrr
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(final DetachedCriteria detachedCriteria, finalint x^X$M$o,l
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pageSize, g#|oif9o
finalint startIndex){ obj!I7
return(PaginationSupport) (![t_r0
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getHibernateTemplate().execute(new HibernateCallback(){ o)p[
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publicObject doInHibernate gJK KR]4*
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(Session session)throws HibernateException { %Lyz_2q A
Criteria criteria = 1|]xo3j"'
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detachedCriteria.getExecutableCriteria(session); ,z G(u 1
int totalCount = nc&Jmo7
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((Integer) criteria.setProjection(Projections.rowCount -zTEL(r
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()).uniqueResult()).intValue(); Xo8DEr
criteria.setProjection NHAH#7]M&1
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(null); iE=P'"I
List items = #52NsVaT@
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criteria.setFirstResult(startIndex).setMaxResults u1N1n;#
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(pageSize).list(); GQ[pG{_+
PaginationSupport ps = =LK}9ViH
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new PaginationSupport(items, totalCount, pageSize, kZv*rWAm
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startIndex); <wa(xDBw
return ps; `36N
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} k2.G%]j
}, true); <6R"h-u"
} =zOeb/
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public List findAllByCriteria(final J.W Ho
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DetachedCriteria detachedCriteria){ LXNQb6!
return(List) getHibernateTemplate \lW_f{X)
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().execute(new HibernateCallback(){ &XtRLtgS
publicObject doInHibernate x9~[HuJ
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(Session session)throws HibernateException { ,VWGq@o%
Criteria criteria = 3nrqo<X
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detachedCriteria.getExecutableCriteria(session); "wINBya'M
return criteria.list(); L+t[&1cW
} S>#R_H<(
}, true); s1=+::
} . ,R4WA,
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public int getCountByCriteria(final A9;0y jae
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DetachedCriteria detachedCriteria){ ;'^, ,{
Integer count = (Integer) )2V@ p~k?
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getHibernateTemplate().execute(new HibernateCallback(){ Z2bUs!0
publicObject doInHibernate R8 jovr
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(Session session)throws HibernateException { r[!(?%>j
Criteria criteria = uREu2T2
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detachedCriteria.getExecutableCriteria(session); K:_($X]
return !F$R+A+L
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criteria.setProjection(Projections.rowCount Hk9U&j$
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()).uniqueResult(); /WYh[XKe
} dhtb?n{
}, true); 1a8$f5
return count.intValue(); 5r7h=[N
} $H;+}VQ
} KoF
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用户在web层构造查询条件detachedCriteria,和可选的 CC#C
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 PUCx]5
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PaginationSupport的实例ps。 wDw<KU1UK
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ps.getItems()得到已分页好的结果集 ?wCs&tM
ps.getIndexes()得到分页索引的数组 2*Q3.2 Z
ps.getTotalCount()得到总结果数 Y&GuDLUF
ps.getStartIndex()当前分页索引 ,C:o`fQ\
ps.getNextIndex()下一页索引 $3#%aA!(#
ps.getPreviousIndex()上一页索引 FUqt)YHi
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 C0<YH "
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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 *~;8N|4<
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一下代码重构了。 >qpqQ;
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我把原本我的做法也提供出来供大家讨论吧: ;"@ :}_t
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首先,为了实现分页查询,我封装了一个Page类: De]^&qw(
java代码: ?!7
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/*Created on 2005-4-14*/ GA@ Ue9
package org.flyware.util.page; c/'M#h)"
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/** 4m /TW)
* @author Joa HfZtL
* aTClw<6}
*/ WHk/$7_"i
publicclass Page { OL9]*G?F
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/** imply if the page has previous page */ F[]&