Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 _=_<cgy1u
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .$]-::&
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 j;BlpRD}
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 k}0b7er=R
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分页支持类: 4 '5|YGQj
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java代码: B[s
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package com.javaeye.common.util; w+u1"
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import java.util.List; /B<QYvv
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publicclass PaginationSupport { SQDfDrYP
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publicfinalstaticint PAGESIZE = 30; g OK
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privateint pageSize = PAGESIZE; d:pGdr& .
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privateList items; yA#nnu1
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privateint totalCount; C6'K)P[p
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privateint[] indexes = newint[0]; K3k{q90
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privateint startIndex = 0; MK(~
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public PaginationSupport(List items, int :$*@S=8 O
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totalCount){
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setPageSize(PAGESIZE); zGNmc7
setTotalCount(totalCount); JwQ/A[b
setItems(items); =~>g--^U
setStartIndex(0); WbwwI)1
} sYbmL`{
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public PaginationSupport(List items, int nS](d2
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totalCount, int startIndex){ zpjE_|
setPageSize(PAGESIZE); @H8DGeM
setTotalCount(totalCount); (K_{a+$[
setItems(items); 5z&>NI
setStartIndex(startIndex); 6Ad C
} 1obajN
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public PaginationSupport(List items, int ^YJ%^P
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totalCount, int pageSize, int startIndex){ Zo,066'+[.
setPageSize(pageSize); L{rd',
setTotalCount(totalCount); W{c
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setItems(items); h5(OjlMC
setStartIndex(startIndex); hr!'
} |nfMoUI
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publicList getItems(){ _+X-D9j(l
return items; p| ?FA@ 3
} 0Py*%}r1
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publicvoid setItems(List items){ ]tzF
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this.items = items; 7pou(U
} IdM~'
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publicint getPageSize(){ LmytO$?2(
return pageSize; fm L8n<1
} d8iq9AP\o
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publicvoid setPageSize(int pageSize){ S9{A}+"K
this.pageSize = pageSize; jtUqrJFlQ
} qtmKX
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publicint getTotalCount(){ w2 r
return totalCount; zez|l
} |s;']
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publicvoid setTotalCount(int totalCount){ \VA*3U^@
if(totalCount > 0){ D*j^f7ab
this.totalCount = totalCount; x[0O*ty-*<
int count = totalCount / RD46@Q`
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pageSize; (k8}9[3G
if(totalCount % pageSize > 0) +H28 F_#
count++; KK6n"&TVa
indexes = newint[count]; wSw> UU
for(int i = 0; i < count; i++){ i4]oE&G
indexes = pageSize * j8nkNE]&
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} k(M:#oA!
}else{ [Ky3WppR
this.totalCount = 0; x
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} bAbR0)
} ,ryL("G
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publicint[] getIndexes(){ a HVzBcCPh
return indexes; :.r_4$F:
} I~:gi@OVV
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publicvoid setIndexes(int[] indexes){
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this.indexes = indexes; *AYq:n6
} :m(DRD
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publicint getStartIndex(){ ZPyzx\6\
return startIndex; r fzNw
} mBE&>}G<
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publicvoid setStartIndex(int startIndex){ *yaS^k\
if(totalCount <= 0) 0y6M;"&~E
this.startIndex = 0; &!OEd]
elseif(startIndex >= totalCount) *ziR &Fr!
this.startIndex = indexes yIrJaS-
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[indexes.length - 1]; ]8}51y8
elseif(startIndex < 0) o<G#%9j
this.startIndex = 0; "VZXi_P
else{ u*TC8!n
this.startIndex = indexes B\v+C!/f|
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[startIndex / pageSize]; ^lAM /
} 8;V9%h`P>
} nYFrp)DLK
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publicint getNextIndex(){ YZj*F-}
int nextIndex = getStartIndex() + NC#F:M;b
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pageSize; *8WB($T}
if(nextIndex >= totalCount) 7jgj;%
return getStartIndex(); m1U:&{:^
else *<\K-NSL
return nextIndex; @phVfP"M
} 5,pNqXRp
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publicint getPreviousIndex(){ PO`p.("h
int previousIndex = getStartIndex() - C+llA
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pageSize; D%abBE1
if(previousIndex < 0) USEb} M`
return0; 0z8?6~M;<
else Jsysk $R
return previousIndex; L23}{P
} \gk.[={^P
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} mAtqF
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抽象业务类 F5Z,Jmi^M
java代码: d=PX}o^
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/** \&5V';
* Created on 2005-7-12 !Aw^X} C
*/ b,E ?{uG
package com.javaeye.common.business; D &"D[|@
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import java.io.Serializable; %bAQ>E2;m
import java.util.List; +cfEyiub
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import org.hibernate.Criteria; MLu!8dgI
import org.hibernate.HibernateException; d_,5;M^k
import org.hibernate.Session; >ESVHPj]
import org.hibernate.criterion.DetachedCriteria; #*'Qm
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import org.hibernate.criterion.Projections; Dz(\ ?
import S^eem_C
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org.springframework.orm.hibernate3.HibernateCallback; x,!Dd
import 1)56ec<c
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org.springframework.orm.hibernate3.support.HibernateDaoS @ph!3<(In,
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upport; LE\=Y;%
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import com.javaeye.common.util.PaginationSupport; Yv5H41o"
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public abstract class AbstractManager extends *Jd"3Si/
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HibernateDaoSupport { #h5lz%2g
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privateboolean cacheQueries = false; kAQ(8xV
) *~A|[
privateString queryCacheRegion; 1f`De`zXzr
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publicvoid setCacheQueries(boolean m2c'r3 UEu
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cacheQueries){ ;=Ma+d#
this.cacheQueries = cacheQueries; *an Ng<@
} >fH0>W+!
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publicvoid setQueryCacheRegion(String
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queryCacheRegion){ ~U0%}Bbh
this.queryCacheRegion = |O{N_-];.
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queryCacheRegion; eDJnzh83
} X0G,tl
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publicvoid save(finalObject entity){ &h-_|N
getHibernateTemplate().save(entity); MJ|tfQwhx
} wJy]Vyd
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publicvoid persist(finalObject entity){ <]qNjsdb9"
getHibernateTemplate().save(entity); 3iCe5VF
} wa"0`a:`;
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publicvoid update(finalObject entity){ {821e&r
getHibernateTemplate().update(entity); CS7b3p!I
} u>*a@3$f
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publicvoid delete(finalObject entity){ (S~kyU!)0
getHibernateTemplate().delete(entity); cx\E40WD
} qGk.7wf%
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publicObject load(finalClass entity, DYf QlA
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finalSerializable id){ ;m]V12
return getHibernateTemplate().load ZcN0:xU
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(entity, id); Kh]es,$D
} #a e@VedM
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publicObject get(finalClass entity, a*P v^Np-v
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finalSerializable id){ ;_,jy7lf
return getHibernateTemplate().get 7Qd4L.
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(entity, id); h`&TDB2
} Kxsd@^E
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publicList findAll(finalClass entity){ SZWNN#w60?
return getHibernateTemplate().find("from LT%~Cuf
=XfvPBA
" + entity.getName()); {7:1F)Pj
} Y25`vE(
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publicList findByNamedQuery(finalString >z<L 60S
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namedQuery){ 5U2%X
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return getHibernateTemplate Et 0gPX-
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().findByNamedQuery(namedQuery);
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} K)'[^V Xh
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publicList findByNamedQuery(finalString query, V%R]jbHZ#
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finalObject parameter){ 8-;.Ejz!\A
return getHibernateTemplate ,RPb<3
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().findByNamedQuery(query, parameter); ?NoNg^ Of
} fbApE
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publicList findByNamedQuery(finalString query, RuHDAJ"&a
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finalObject[] parameters){
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return getHibernateTemplate 1I2ndt
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().findByNamedQuery(query, parameters); ]xS%Er
} ie1~QQ
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publicList find(finalString query){ ]9QXQH
return getHibernateTemplate().find ;6V~yB
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(query); G? SPz
} )u(,.O[cw
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publicList find(finalString query, finalObject [r2V+b.C
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parameter){ 8(? &=>@
return getHibernateTemplate().find Jq^[^
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(query, parameter); ,zjz "7'
} Y~Uf2(7b5
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public PaginationSupport findPageByCriteria $?ss5:
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(final DetachedCriteria detachedCriteria){ PS~_a
return findPageByCriteria E?]$Y[KJKs
'l<#;{
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 7^>~k}H
} H ezbCwsx&
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public PaginationSupport findPageByCriteria x}ZXeqt{{
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(final DetachedCriteria detachedCriteria, finalint /R|?v{S1
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startIndex){ Csu9u'.V
return findPageByCriteria OsOfo({I_
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(detachedCriteria, PaginationSupport.PAGESIZE, 'z91aNG]
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startIndex); U2`:'
} VK/L}^=GOO
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public PaginationSupport findPageByCriteria X[/7vSqZ@w
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(final DetachedCriteria detachedCriteria, finalint |g hyH
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pageSize, 2?qT,pN
finalint startIndex){ I*3>>VN
return(PaginationSupport) p63fpnH
q>+!Ete1p
getHibernateTemplate().execute(new HibernateCallback(){ y:E$n!
publicObject doInHibernate fx>QP?Z
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(Session session)throws HibernateException { |7K>`
Criteria criteria = "uplk8iCJ
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detachedCriteria.getExecutableCriteria(session); zn/>t-Bc
int totalCount = ,]t_9B QK
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((Integer) criteria.setProjection(Projections.rowCount Lt~&K$t7~
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()).uniqueResult()).intValue(); E\}A<r
criteria.setProjection sw9ri}oc
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(null); C\{ KB@C\*
List items = |A68+(3u
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criteria.setFirstResult(startIndex).setMaxResults jjrE8[
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(pageSize).list(); 8@doKOA~T
PaginationSupport ps = k"=*'
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new PaginationSupport(items, totalCount, pageSize, N=U`BhL_
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startIndex); W$7H "tg
return ps; GfSD%"
} Y4N7# 5
}, true); W NeBthq6
} *oLDy1<
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public List findAllByCriteria(final W9}
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DetachedCriteria detachedCriteria){ {\k }:)
return(List) getHibernateTemplate B&7:=t,m(
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().execute(new HibernateCallback(){ Aua}.Fl,
publicObject doInHibernate UvU@3[fw
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(Session session)throws HibernateException { T++q.oFc
Criteria criteria = @#^Y#
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detachedCriteria.getExecutableCriteria(session); /V cbT >=
return criteria.list(); Jza?DhSAZ
} p7{H
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}, true); 0)zJG |
} O46v
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public int getCountByCriteria(final _KtV`bF
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DetachedCriteria detachedCriteria){ [jCYj0Qf8
Integer count = (Integer) sZ7,7E|_
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getHibernateTemplate().execute(new HibernateCallback(){ Z0v?3v}9^
publicObject doInHibernate }(DH_0
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(Session session)throws HibernateException { LPs5LE[Pm
Criteria criteria = o\><e1P
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detachedCriteria.getExecutableCriteria(session); $e4N4e2x/
return @+~>utr
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criteria.setProjection(Projections.rowCount Wt@hST
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()).uniqueResult(); pd`m//G
} CAx
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}, true); !/a6;:_y
return count.intValue(); O3T7O`H[
} k{S8q?Gc
} ShlTMTgS
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用户在web层构造查询条件detachedCriteria,和可选的 8QL=%Pv
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 FG!hb?_1
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PaginationSupport的实例ps。 ;ThFB
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ps.getItems()得到已分页好的结果集 {98e_z w
ps.getIndexes()得到分页索引的数组 O0
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ps.getTotalCount()得到总结果数 k'
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ps.getStartIndex()当前分页索引 A)j!Wgs^z
ps.getNextIndex()下一页索引 ^~vM*.j~j
ps.getPreviousIndex()上一页索引 2 A";oE
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 =-r); d
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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 |*b-m k
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一下代码重构了。 UU[z\^w| E
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我把原本我的做法也提供出来供大家讨论吧: .9r85
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首先,为了实现分页查询,我封装了一个Page类: '3sySsD&O
java代码: %I!2dXNFRF
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/*Created on 2005-4-14*/ ZQ*Us*9I
package org.flyware.util.page; ;PMh>ZE`
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/** h~CLJoK<
* @author Joa 75>Ok /
* .L"IG=Uh#
*/ -r3
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publicclass Page { u3,O)[qV
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/** imply if the page has previous page */ ]e7?l/N[
privateboolean hasPrePage; L@zhbWY
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/** imply if the page has next page */ aHYISjZ]>
privateboolean hasNextPage; -/Wf iE
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/** the number of every page */ &dK!+
privateint everyPage; "dDrw ]P;
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/** the total page number */ ,=[%#gS
privateint totalPage; FY^Nn
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/** the number of current page */ <Q- m &
privateint currentPage; ;y1/b(t
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/** the begin index of the records by the current "8cI]~V
tk=S4/VWv
query */ YOrq)_ l
privateint beginIndex; 7:b.c
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/** The default constructor */ hLk6Hqr7
public Page(){ %OO}0OW
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} ).(y#zJ7P
*W^ZXhrZ
/** construct the page by everyPage r;[ =y<Yf
* @param everyPage +DR$ >a
* */ d(ypFd9z
public Page(int everyPage){ T{f$S
this.everyPage = everyPage; Qe ip h
} ]PoWL;E'
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/** The whole constructor */ 0{8L^
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public Page(boolean hasPrePage, boolean hasNextPage, %-.;sO=g
p)?6#~9$
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int everyPage, int totalPage, S7PWP<9
int currentPage, int beginIndex){ sO6=w%l^
this.hasPrePage = hasPrePage; yrfV&C%=n
this.hasNextPage = hasNextPage; r@Jy*2[-Jq
this.everyPage = everyPage; %Pt){9b
this.totalPage = totalPage; /}L2LMIm
this.currentPage = currentPage; &TA{US3~
this.beginIndex = beginIndex; ]Zc|<f;
} -rm[.
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/** e3 :L]4t
* @return Iapz,nuE
* Returns the beginIndex. ~eoM
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*/ 09G47YkSy1
publicint getBeginIndex(){ <.gDg?'3
return beginIndex; GfEWms8z
} m}=E$zPbO
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/** 9jEH"`qqk
* @param beginIndex h3 XSt
* The beginIndex to set. 0*rD'?)K+
*/ b"N!#&O