Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 \)LY_D:
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 WlG/7$
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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 #<l;YT8
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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 b}k`'++2,
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分页支持类: h`jtmhoz
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java代码: <;_X=s`f,
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package com.javaeye.common.util; 6h;$^3x$
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import java.util.List; 2uqdx'^"
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publicclass PaginationSupport { +/AW6
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publicfinalstaticint PAGESIZE = 30; a}%>i~v<
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privateint pageSize = PAGESIZE; h5B'w
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privateList items; 3<?(1kSo>>
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privateint totalCount; .PxtcC.K
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privateint[] indexes = newint[0]; /z~;.jRg
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privateint startIndex = 0; Jfo#IRC
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public PaginationSupport(List items, int 8'/vW ~f
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totalCount){ J
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setPageSize(PAGESIZE); qI KVu_
setTotalCount(totalCount); LLV:E{`p
setItems(items); Q>= :$I
setStartIndex(0); ,zz+s[ZH7O
} h<.&,6R
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public PaginationSupport(List items, int z l@
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totalCount, int startIndex){ f~8Xue,l"
setPageSize(PAGESIZE); &5c)qap;n
setTotalCount(totalCount); T[&1cth
setItems(items); Bo)w#X
setStartIndex(startIndex); -=2tKH`Q
} qp'HRh@P2:
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public PaginationSupport(List items, int |*jnJWH4:
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totalCount, int pageSize, int startIndex){ .k Gg}
setPageSize(pageSize); (4x`/
setTotalCount(totalCount); pz#oRuujY
setItems(items); O-5H7Kd-
setStartIndex(startIndex); '+5*ajP<
} 0P&rTtU6
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publicList getItems(){ ^ JJ*pT:
return items; -05#/-Z=
} ?0Z?Z3)%w4
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publicvoid setItems(List items){ d1vC-n
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this.items = items; iO>2#p8$NR
} Z2j
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publicint getPageSize(){ j[
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return pageSize; ,*wa#[
} z3[
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publicvoid setPageSize(int pageSize){ Nu<M~/
this.pageSize = pageSize; I?EtU/AD
} >5'C<jc C
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publicint getTotalCount(){ U#G0
return totalCount; _.KKh62CN
} ,n-M!y
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publicvoid setTotalCount(int totalCount){ vB
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if(totalCount > 0){ PB(mUD2"r
this.totalCount = totalCount; \U\ W Q
int count = totalCount / ncuqo'r
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pageSize; rB}Iwp8
if(totalCount % pageSize > 0) +Vl\lL
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count++; xRuAt/aC
indexes = newint[count]; -iLp3m<ai
for(int i = 0; i < count; i++){ fb0i6RC~&
indexes = pageSize * )! Jo7SR
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} eG55[V<!
}else{ *9Ej fs7L
this.totalCount = 0; 2? 9*V19yu
} 7k.=_Tl
} AqM}@2#%%
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publicint[] getIndexes(){ 4^/MDM@
return indexes; C2OBgM+
} \qj4v^\
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publicvoid setIndexes(int[] indexes){ efW<
this.indexes = indexes; )zzZYs&|
} { }Q!./5
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publicint getStartIndex(){ W@Et
return startIndex; Ac{"$P`
} 9ozN$:
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publicvoid setStartIndex(int startIndex){ .dM4B'OA?
if(totalCount <= 0) Wwo'pke
this.startIndex = 0; ,Q:Ylc8
elseif(startIndex >= totalCount) )nE=H,U?y
this.startIndex = indexes }rK9M$2]u
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[indexes.length - 1]; jRdmQmTJ
elseif(startIndex < 0) Esx"nex
this.startIndex = 0; Ns
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else{ \zOo[/-<
this.startIndex = indexes O\0]o!
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[startIndex / pageSize]; LkvR]^u0
} "]H_;:{f
} nSR7$yS_
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publicint getNextIndex(){ XM?>#^nC?u
int nextIndex = getStartIndex() + vNo(`~]c
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pageSize; }[2
if(nextIndex >= totalCount) 9W5~I9%
return getStartIndex(); %BBM%Lj
else <yNu/B.M
return nextIndex; f%ThS42
} q)N]*~
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publicint getPreviousIndex(){ Ov<EOK+^
int previousIndex = getStartIndex() - R"Ff(1m
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pageSize; YL[n85l>1
if(previousIndex < 0) ^\"@r%|
return0; 4{zz-4=
else {~*^jS']5
return previousIndex; 8_*31Y
} yq7gBkS
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} Gn?NY}.S
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抽象业务类 v~.nP}
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java代码: c;6[lv
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/** ?:woUTyCv
* Created on 2005-7-12 `xXpP"*o}
*/ `AcUxnO
package com.javaeye.common.business; w ag^Sk
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import java.io.Serializable; 5|<j Pc
import java.util.List; 3u,C I!
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import org.hibernate.Criteria; xCTPsw]s
import org.hibernate.HibernateException; R]LuZN
import org.hibernate.Session; /XVjcD66c
import org.hibernate.criterion.DetachedCriteria; d8!yV~Ka
import org.hibernate.criterion.Projections; QKB*N)%6
import (/ qOY
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org.springframework.orm.hibernate3.HibernateCallback; ]_5qME#N
import 3xX^pjk
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org.springframework.orm.hibernate3.support.HibernateDaoS /$=<"Y7&g
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upport; <
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import com.javaeye.common.util.PaginationSupport; A||,|He~
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public abstract class AbstractManager extends &l8eljg
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HibernateDaoSupport { ,L&d\M"f
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privateboolean cacheQueries = false; *,FU*zi
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privateString queryCacheRegion; q).["fSV
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publicvoid setCacheQueries(boolean +5i~}Q!
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cacheQueries){ mDdL7I
this.cacheQueries = cacheQueries; M 8NWQ^Y
} +ktubJ@Qgj
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publicvoid setQueryCacheRegion(String V'^E'[Dd{
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queryCacheRegion){ =@ d/SZ|(E
this.queryCacheRegion = J?%e cCN
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queryCacheRegion; 'ju'O#A9
} b!4Z~d0=
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publicvoid save(finalObject entity){ up!54}qy
getHibernateTemplate().save(entity); PpLuN12H
} ^61;0
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publicvoid persist(finalObject entity){ s H(io
getHibernateTemplate().save(entity); w| eVl{~p
} ,(3oAj\
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publicvoid update(finalObject entity){ x8!uI)#tS
getHibernateTemplate().update(entity); 6an= C_Mb`
} POI|#[-V
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publicvoid delete(finalObject entity){ 8J)Kn4jq
getHibernateTemplate().delete(entity); 6L<QKE=
} 25Uw\rKeO
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publicObject load(finalClass entity, |)*9BN
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finalSerializable id){ A5E^1j}h@
return getHibernateTemplate().load ?mHu eX
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(entity, id); |OiM(E(
} v^dQ%+}7>
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publicObject get(finalClass entity, d7G
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finalSerializable id){ 4I8QM&7
return getHibernateTemplate().get qVssw* GDB
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(entity, id); ns#v?D9NF
} `ES+$ O>
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publicList findAll(finalClass entity){ 4\E1M[ 6
return getHibernateTemplate().find("from Van=dzG
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" + entity.getName()); O7oq1JI]Y
} O%f{\Fr
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publicList findByNamedQuery(finalString 'cqY-64CJZ
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namedQuery){ PqMu2 e
return getHibernateTemplate \M;cF"e-S
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().findByNamedQuery(namedQuery); G-|
} +4+czfz
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publicList findByNamedQuery(finalString query, +2w<V0V_
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finalObject parameter){ z31g"
return getHibernateTemplate P%;lHC #i
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().findByNamedQuery(query, parameter); U|<>xe*|%
} F:sUGM,
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publicList findByNamedQuery(finalString query, e8M0Lz#}
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finalObject[] parameters){ W$<Y**y9m
return getHibernateTemplate X]D:vuB
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().findByNamedQuery(query, parameters); >2v<;.
} E#Ol{6
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publicList find(finalString query){ _U9.u#>sV
return getHibernateTemplate().find >S8
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(query); h8 FV2"
} uqD|j:~ =k
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publicList find(finalString query, finalObject #.vp\W
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parameter){ x=-(p}0o;<
return getHibernateTemplate().find e jR_3K^
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(query, parameter); u08j9)
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} j{johV+`8
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public PaginationSupport findPageByCriteria O0s,)8+z5D
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(final DetachedCriteria detachedCriteria){ $inKI
return findPageByCriteria ^Nu j/
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); S<jiy<|`
} 6@"E*-z$
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public PaginationSupport findPageByCriteria -0TI7 @
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(final DetachedCriteria detachedCriteria, finalint g}IOHE
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startIndex){ \y6Y}Cv
return findPageByCriteria h6bvUI+|h
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(detachedCriteria, PaginationSupport.PAGESIZE, N<<O(r
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startIndex); ';}:*nZ//_
} |onLJY7)
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public PaginationSupport findPageByCriteria O9m sPb:
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(final DetachedCriteria detachedCriteria, finalint m%UF{I,
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pageSize, !&cfX/y8
finalint startIndex){ WncHgz
return(PaginationSupport) 0l/7JH_@V
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getHibernateTemplate().execute(new HibernateCallback(){ -0BxZ AW=
publicObject doInHibernate 9P,[MZ
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(Session session)throws HibernateException { LpI4R
Criteria criteria = j}K3YfH
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detachedCriteria.getExecutableCriteria(session); Dx=RLiU9
int totalCount = Q@8(e&{#W
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((Integer) criteria.setProjection(Projections.rowCount &x=_n'
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()).uniqueResult()).intValue(); PW iuM=E
criteria.setProjection o(
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(null); ueg%D+u
List items = wAgVevE
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criteria.setFirstResult(startIndex).setMaxResults f`K#=_Kq7
,_/\pX0
(pageSize).list(); XD?]+
PaginationSupport ps = 2yD ?f8P4
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new PaginationSupport(items, totalCount, pageSize, lqgR4 !
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startIndex); /VP #J<6L
return ps; Cs,Cb2[
} UUM:*X
}, true); #c"05/=A
} R?,v:S&i7;
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public List findAllByCriteria(final T,Q7 YI
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DetachedCriteria detachedCriteria){ %Wm)
return(List) getHibernateTemplate EP<{3fy
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().execute(new HibernateCallback(){ 1K)9fMr]
publicObject doInHibernate T-lP=KF=
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(Session session)throws HibernateException { +z#+}'mT%
Criteria criteria = hOV5WO\
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detachedCriteria.getExecutableCriteria(session); Sj*W|n\gj
return criteria.list(); tu@-+<*
} > PL}7f&:
}, true); a*_&[
} Xk:3w,
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public int getCountByCriteria(final mi5bk>o
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DetachedCriteria detachedCriteria){ x>Dix1b:.
Integer count = (Integer) "jq6FT)O
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getHibernateTemplate().execute(new HibernateCallback(){ v}z^M_eFm
publicObject doInHibernate ;<6S\
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(Session session)throws HibernateException { h+cOOm-)
Criteria criteria = . S;o#Zw*R
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detachedCriteria.getExecutableCriteria(session); *+2BZZwT
return zxd<Cq>d
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criteria.setProjection(Projections.rowCount :9q|<[Y^
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()).uniqueResult(); 1-<?EOYaE
} x[BA <UNO
}, true); Q&PEO%/D
return count.intValue(); 5g'aNkF6>
} Xg;<?g?k
} N>g6KgX{K
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用户在web层构造查询条件detachedCriteria,和可选的 Iu;VFa
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 >{rD3X"d
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PaginationSupport的实例ps。 Z%SDN"+'g
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ps.getItems()得到已分页好的结果集 bZ+Hu~
ps.getIndexes()得到分页索引的数组 C
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ps.getTotalCount()得到总结果数 ? fM_Y
ps.getStartIndex()当前分页索引 ; H]]H!
ps.getNextIndex()下一页索引 ^~bAixH^k
ps.getPreviousIndex()上一页索引 cz$*6P<9J
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 G49`a*Jn
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 }\W^$e-
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一下代码重构了。 ^Uik{x
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我把原本我的做法也提供出来供大家讨论吧: 0!1cHB/c
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首先,为了实现分页查询,我封装了一个Page类: SMA' VU
java代码: zogl2e+
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/*Created on 2005-4-14*/ O[9A} g2~
package org.flyware.util.page; D}nRH@<`
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/** ;!H]&2`'(
* @author Joa v%E!
* /@LUD=
*/ FyllVrK
publicclass Page { !L@a;L
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/** imply if the page has previous page */ C4eQ.ep
privateboolean hasPrePage; [-3x *?Ju
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/** imply if the page has next page */ XILreATK@
privateboolean hasNextPage; ?]58{O(?c
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/** the number of every page */ mX@!O[f%9e
privateint everyPage; ;2,Q:&`
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/** the total page number */ ()(/9t
privateint totalPage; JZoH -
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/** the number of current page */ ,4S6F HK
privateint currentPage; "jP{m;p
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/** the begin index of the records by the current A04E <nr
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query */ *|3G"B{w6
privateint beginIndex; `it
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/** The default constructor */ H>|*D~RdT
public Page(){ =_vW7-H
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} f^@DuI
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/** construct the page by everyPage je5GZFQw
* @param everyPage N/r8joi#
* */ NFBhnNH+
public Page(int everyPage){ M1e79p<
this.everyPage = everyPage; pXoT@[}
} Ydh+iLjhx
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