Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Xw}Y!;<IEu
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 G4J6
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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 p7=^m>Z6
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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 a ~iEps
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分页支持类: d# ?*62
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java代码: -_f0AfU/a
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package com.javaeye.common.util; +?m=f}>W1
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import java.util.List; _G8y9!J
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publicclass PaginationSupport { #FDu4xi
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publicfinalstaticint PAGESIZE = 30; 0c;"bA0>Sx
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privateint pageSize = PAGESIZE; 7a.#F]`
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privateList items; UY& W]
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privateint totalCount; X1~A "sW[
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privateint[] indexes = newint[0]; z+B
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privateint startIndex = 0; G u I sM
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public PaginationSupport(List items, int zW&O>H
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totalCount){ O6 J<Lqgh
setPageSize(PAGESIZE); 8l,hP .
setTotalCount(totalCount); Iur} ZAz
setItems(items); 8@#Y
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setStartIndex(0); L}pFb@
} n>+W]I&E
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public PaginationSupport(List items, int &otgN<H9
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totalCount, int startIndex){ }u)GERWO
setPageSize(PAGESIZE); #gT^hl5/
setTotalCount(totalCount); No|{rYYKK
setItems(items); 9!C?2*>A P
setStartIndex(startIndex); d> AmM!J
} ~ZC=!|Q#
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public PaginationSupport(List items, int "Jd1&FsCwX
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totalCount, int pageSize, int startIndex){ KO"iauW
setPageSize(pageSize); ?P]md9$(+e
setTotalCount(totalCount); 5!%/j,?
setItems(items); ]<= t
setStartIndex(startIndex); 6&T1
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} >,2],X"G
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publicList getItems(){ [: j_Y3-9
return items; Or|LyQU
} gJ7puN
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publicvoid setItems(List items){ \H(,'w7H
this.items = items; nQ6'yd"
} \ed(<e>
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publicint getPageSize(){ XrF9*>ti?
return pageSize; ,{at?y*
} oPir]`re
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publicvoid setPageSize(int pageSize){ ma~`&\xE
this.pageSize = pageSize; H[Cn@XE
} VGIc|Q=F
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publicint getTotalCount(){ )-oNy-YL
return totalCount; ZAwl,N){
} z_TK
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publicvoid setTotalCount(int totalCount){ [u:_Jqf-
if(totalCount > 0){ 7;{F"/A
this.totalCount = totalCount; zx*f*L,6F
int count = totalCount / #96a7K
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pageSize; 8iRQPV-"_
if(totalCount % pageSize > 0) "mA/:8` Q
count++; ^M"g5+q
indexes = newint[count]; ,*30Q
for(int i = 0; i < count; i++){ /~:ztv\$M"
indexes = pageSize * Kt(p|
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} uJizR
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}else{ 6822xk
this.totalCount = 0; _+i-)
} BKk*<WMD
} _C?K;-v}
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publicint[] getIndexes(){ FB""^IC?W
return indexes; KH-.Z0
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} hwJ.M4
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publicvoid setIndexes(int[] indexes){ 2B#\683
this.indexes = indexes; 8}&cE#@
} 8wOr`ho B
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publicint getStartIndex(){ Z6I!4K
return startIndex; -{?Rq'H
} iZUBw
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publicvoid setStartIndex(int startIndex){ =vWnqF:
if(totalCount <= 0) shD$,!
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this.startIndex = 0; -v:Y\=[\
elseif(startIndex >= totalCount) l!1bmg #]$
this.startIndex = indexes #Xc~3rg9
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[indexes.length - 1]; x?k6ek
elseif(startIndex < 0) W{%M+a[#l
this.startIndex = 0; L:31toGK
else{ '{|87kI
this.startIndex = indexes ,PB?pp8C}
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[startIndex / pageSize]; 87-oR}/r
} QRRZMdEGs[
} _*+M'3&=
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publicint getNextIndex(){ S+He
int nextIndex = getStartIndex() + 3TJNlS
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pageSize; =Vi+wH{xM
if(nextIndex >= totalCount) @+xQj.jNC
return getStartIndex(); bv+PbK]iO
else g,.iM8
return nextIndex; <fP|<>s$@1
} :5dq<>~
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publicint getPreviousIndex(){ f#!Ljjf$;
int previousIndex = getStartIndex() - H6L`239u
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pageSize; 5nk]{ G> V
if(previousIndex < 0) \E n ^Vf
return0; \=w|Zeu{l
else oR5 'g7?
return previousIndex; um[.r,++
} d!>PqPo
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} H=*;3gM,'
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抽象业务类 Qv#]T,
java代码: BeBa4s
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/** %?K'egkp
* Created on 2005-7-12 PKmr5FB
*/ .|!Kv+yD
package com.javaeye.common.business; )[>{
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import java.io.Serializable; X"*pt5B6`
import java.util.List; I_\j05
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import org.hibernate.Criteria; 9[T}cN=|
import org.hibernate.HibernateException; b0t/~]9G
import org.hibernate.Session; Ubv<3syR'
import org.hibernate.criterion.DetachedCriteria; uvi+#4~G
import org.hibernate.criterion.Projections; `StlG=TB8
import
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org.springframework.orm.hibernate3.HibernateCallback; s>ilxLSX]
import saY":fva
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org.springframework.orm.hibernate3.support.HibernateDaoS ,Tjc\;~%
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upport; O!#r2Y"?K1
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import com.javaeye.common.util.PaginationSupport; fgdqp8~
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public abstract class AbstractManager extends /6 QwV->
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HibernateDaoSupport { Qq+$ea?>
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privateboolean cacheQueries = false; W"$sN8K>)
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privateString queryCacheRegion; ZMEU4?F
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publicvoid setCacheQueries(boolean _Fkz^B*
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cacheQueries){ FLUvFD
this.cacheQueries = cacheQueries; x,L<{A`z
} "lLwgh;
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publicvoid setQueryCacheRegion(String 5v5)vv.kd
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queryCacheRegion){ mUA!GzJ~u-
this.queryCacheRegion = h(C@IIO^;G
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queryCacheRegion; AdD,94/
} "rA-u)Te
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publicvoid save(finalObject entity){ =aB c.PJ^
getHibernateTemplate().save(entity); \:-"?
} 7D&O5Z=%+
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publicvoid persist(finalObject entity){ q{Ao
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getHibernateTemplate().save(entity); tJ$gH;
} `:.a5
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publicvoid update(finalObject entity){ ?`T Q'#P`
getHibernateTemplate().update(entity); "*<)pnJ
} ?k`UQi]Q
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publicvoid delete(finalObject entity){ vN&(__3((
getHibernateTemplate().delete(entity); Yz)+UF,
} |BBo
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publicObject load(finalClass entity, Pj8W]SA_
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finalSerializable id){ Gv&%cq1
return getHibernateTemplate().load ~jJF&*)
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(entity, id); m*|G2
} .cm9&&"Z
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publicObject get(finalClass entity, 6<fcG
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finalSerializable id){ Q[Gs%/>
return getHibernateTemplate().get "[ieOFI
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(entity, id); L 8J] X7
} Q[c:A@oW
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publicList findAll(finalClass entity){ y[ZVi5) ,
return getHibernateTemplate().find("from [>LO'}%
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" + entity.getName()); +
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} xb2j
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publicList findByNamedQuery(finalString >}B53.;.k
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namedQuery){
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return getHibernateTemplate >>c%Ic
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().findByNamedQuery(namedQuery); hcpe~spz9|
} f\FqZ?w
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publicList findByNamedQuery(finalString query, `_sKR,LhB
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finalObject parameter){ n\< uT1n
return getHibernateTemplate {mY=LaS<
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().findByNamedQuery(query, parameter); j)wrF@W
} *TrpW?]Y&
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publicList findByNamedQuery(finalString query, b\t?5z-Z
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finalObject[] parameters){ 21my9Ui]
return getHibernateTemplate *uSlp_;kB
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().findByNamedQuery(query, parameters); /z(d!0_q|v
} (Q.tH
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publicList find(finalString query){ hOYX
return getHibernateTemplate().find E2tUL#
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(query); >}/T&S
} GP x+]Jw8\
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publicList find(finalString query, finalObject Od~e*gA8
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parameter){ Nrq/Pkmy
return getHibernateTemplate().find VF +g+~
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(query, parameter); <tm=
} rHqP[[4B'
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public PaginationSupport findPageByCriteria ,Y16m{<eC
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(final DetachedCriteria detachedCriteria){ >[~`rOU*|Y
return findPageByCriteria N8,g~?r^
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); We*uZ?+
} Ft}nG&D
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public PaginationSupport findPageByCriteria F&Rr&m
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(final DetachedCriteria detachedCriteria, finalint FE:}D;$
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startIndex){ yr* ~?\
return findPageByCriteria QWWI
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(detachedCriteria, PaginationSupport.PAGESIZE, K,+z^{Hvh
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startIndex); iG"1~/U
} m:k;?p:x
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public PaginationSupport findPageByCriteria DcC|oU[
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(final DetachedCriteria detachedCriteria, finalint Ef3="}AI;
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pageSize, wzcv[C-x
finalint startIndex){ sp_19u
return(PaginationSupport) @PK
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getHibernateTemplate().execute(new HibernateCallback(){ A'D2uV
publicObject doInHibernate Mp^G7JY,
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(Session session)throws HibernateException { =AF;3
Criteria criteria = Yf1%7+V35
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detachedCriteria.getExecutableCriteria(session); B->oTC`5
int totalCount = <"S`ZOn
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((Integer) criteria.setProjection(Projections.rowCount E{\T?dk1$
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()).uniqueResult()).intValue(); #UvWS
criteria.setProjection 2ppJ;P{k
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(null); jS|jPk|I.
List items = #8%~ u+"N
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criteria.setFirstResult(startIndex).setMaxResults `:dGPBBO
++!0r['+>
(pageSize).list(); MB6lKLy6~
PaginationSupport ps = ,8DjQz0ZPo
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new PaginationSupport(items, totalCount, pageSize, WpkCFp
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startIndex); "msPH<D
return ps; 7+$P6[*
} "&\]1A}Z-x
}, true); y)7;"3Q<
} ko~e*31_E
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public List findAllByCriteria(final uzT>|uu$
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DetachedCriteria detachedCriteria){ <fDbz1Q;l
return(List) getHibernateTemplate A*W/Q<~I
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().execute(new HibernateCallback(){ v5L#H=P
publicObject doInHibernate y*lAmO
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(Session session)throws HibernateException { .Txwp?};
Criteria criteria = [t]q#+Zs
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detachedCriteria.getExecutableCriteria(session); ?1H>k<Jp
return criteria.list(); VWMr\]g
} }G<A$*L1
}, true); #o(@S{(NZ
} /$UWTq/C7
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public int getCountByCriteria(final rU7t~DKS
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DetachedCriteria detachedCriteria){ U5j0i]
Integer count = (Integer) 5pq9x4&
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getHibernateTemplate().execute(new HibernateCallback(){ sV`XJ9e|
publicObject doInHibernate dg;E,'e_
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(Session session)throws HibernateException { K(}<L-cv
Criteria criteria = a0cW=0l=
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detachedCriteria.getExecutableCriteria(session); kk/vgte-)e
return BWsD~Ft
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criteria.setProjection(Projections.rowCount CdiL{zH\3
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()).uniqueResult(); 15!b]':
} 3$kElq[
}, true); ZHc;8|}
return count.intValue(); |r53>,oR<:
} "z|%V/2b3
} avH3{V
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用户在web层构造查询条件detachedCriteria,和可选的 \(xQ'AQ-
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 k3t2{=&'&x
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PaginationSupport的实例ps。 `z3"zso
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ps.getItems()得到已分页好的结果集 VEg/x z4c
ps.getIndexes()得到分页索引的数组 ,=p.Cx'PR
ps.getTotalCount()得到总结果数 .[#bOp*
ps.getStartIndex()当前分页索引 Bn{0-5nj
ps.getNextIndex()下一页索引 64qQ:D7C
ps.getPreviousIndex()上一页索引 &,@wLy^T
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 *npe]cC
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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 Jv=G3=.
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一下代码重构了。 }~28UXb23
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我把原本我的做法也提供出来供大家讨论吧: kpN'H_ .
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首先,为了实现分页查询,我封装了一个Page类: ?V&[U
java代码: QP e}rQnm
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/*Created on 2005-4-14*/ aJ Du_
package org.flyware.util.page; qqYH}%0dz
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/** Uq6..<#
* @author Joa *7I=vro
* !Jj=H()}
*/ z
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publicclass Page { (Rk g
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/** imply if the page has previous page */ JPk3T.qp
privateboolean hasPrePage; VMW?[j
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/** imply if the page has next page */ AsM""x1Ix
privateboolean hasNextPage; sh?Dxodp9
x9HA^Rj4-
/** the number of every page */ T+2I:W%
privateint everyPage; q6{ %vd
f|FQd3o)
/** the total page number */ /7h%sCX
privateint totalPage; nZN]Q9
"O|fX\}5
/** the number of current page */ Y^S0K'N
privateint currentPage; 9#6ilF:F
tO?*x/XC{
/** the begin index of the records by the current wR/i+,K
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query */ Dl/UZ@8pl
privateint beginIndex; <z)MV
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/** The default constructor */ :eQxdi'
public Page(){ x)vYc36H
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} rmQGzQnun
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/** construct the page by everyPage x'JfRz
* @param everyPage 2 >xV&