Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 1(C3;qlVD
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 41luFtE9
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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 6Q]c]cCu
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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 D`]Lm 24_]
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分页支持类: ~@ZdO+n?
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java代码: uG1
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package com.javaeye.common.util; n`";ctQT
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import java.util.List; D8P<mIu}Y
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publicclass PaginationSupport { %lZ++?&^
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publicfinalstaticint PAGESIZE = 30; KE\p|X i
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privateint pageSize = PAGESIZE; G5W6P7-<X
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privateList items; }5gAxR,
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privateint totalCount; usiv`.
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privateint[] indexes = newint[0]; :A35?9E?
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privateint startIndex = 0; ?29zcuRaru
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public PaginationSupport(List items, int )e.Y"5My
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totalCount){ frS1<+
setPageSize(PAGESIZE); <VV./W8e9
setTotalCount(totalCount); xq_%|p}y
setItems(items); ,]@ K6
setStartIndex(0); q;3,}emg
} kYBTmz}z
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public PaginationSupport(List items, int )@.bkzW
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totalCount, int startIndex){ QjETu
setPageSize(PAGESIZE); iMRb`
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setTotalCount(totalCount); K1>.%m
setItems(items); %]%.{W\j3
setStartIndex(startIndex); ^_b+o
} F/9]{H
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public PaginationSupport(List items, int <apsG7(7
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totalCount, int pageSize, int startIndex){ vQ=W<>1
setPageSize(pageSize); "pq#A*
setTotalCount(totalCount); ]#]m_+} Z
setItems(items); Saa#Mj`M
setStartIndex(startIndex); \dj&4u3
} PT4Xr=z =
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publicList getItems(){ L%`~`3%n-
return items; CBx 1.xL
} H=]$9ZH!
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publicvoid setItems(List items){ {\22C `9t
this.items = items; B]dHMLzl
} \7Hzj0hSi
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publicint getPageSize(){ DUf=\p6`f
return pageSize; m`C(y$8fU
} V x1C4
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publicvoid setPageSize(int pageSize){ Hno@
this.pageSize = pageSize; ?RGL0`Lg
} GutH}Kz"&
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publicint getTotalCount(){ *v3/8enf
return totalCount; aNb=gjLpt
}
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publicvoid setTotalCount(int totalCount){ L>$yslH;b
if(totalCount > 0){ (8o~ XL
this.totalCount = totalCount; B1m@
int count = totalCount / \~:Kp
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pageSize; z<c^<hE:l
if(totalCount % pageSize > 0) %Rv&VFg
count++; BDZB;DPb
indexes = newint[count]; y
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for(int i = 0; i < count; i++){ W>eJGZ<
indexes = pageSize * b_-ESs]g
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} ug[|'tR8
}else{ rz+G]J
this.totalCount = 0; N kp>yVj
} '1;Q'-/J
} aWek<Y~+
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publicint[] getIndexes(){ t/WauY2JUC
return indexes; Y2vzK;
} qC?J`
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publicvoid setIndexes(int[] indexes){ <.(IJ
this.indexes = indexes; Yo;/7gG>
} t,=
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publicint getStartIndex(){ .:Bjs*
return startIndex; wxpD{P
} 6~?7CK
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publicvoid setStartIndex(int startIndex){ CyO2Z
if(totalCount <= 0) p%,:U8fOR
this.startIndex = 0; ElhTB
elseif(startIndex >= totalCount) o%X_V!B{V
this.startIndex = indexes `x$d8(1J`#
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[indexes.length - 1]; X!&DKE
elseif(startIndex < 0) M_+&XLnzsJ
this.startIndex = 0; !y$Hr[v
else{ W?~G_4
this.startIndex = indexes q,VJpqQ
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[startIndex / pageSize];
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} @gENv~m<OI
} q7mqzMDk
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publicint getNextIndex(){ ZH/^``[.
int nextIndex = getStartIndex() + {"!V&}
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pageSize; 3 8pw
if(nextIndex >= totalCount) kt%9PGw
return getStartIndex(); soW.
else 7&XU]I
return nextIndex; %!%3jo0t
} ?{%P9I
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publicint getPreviousIndex(){ 5tHv'@
int previousIndex = getStartIndex() - OP]=MZP|
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pageSize; (~xFd^W9o
if(previousIndex < 0) &>0=v
return0; Tk$rwTCl
else !I]fNTv<
return previousIndex; W=}l=o!G.
} p.TR1BHw
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} xr?=gY3E;
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抽象业务类 ~6.AE/ow
java代码: >Mj :'
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/** Jx1oK
* Created on 2005-7-12 6[wej$u
*/ ~[Mk QJxe
package com.javaeye.common.business; (ZQ{%-i?qR
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import java.io.Serializable; E:xpma1Qf
import java.util.List; kLMg|48fdI
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import org.hibernate.Criteria; (`GO@
import org.hibernate.HibernateException; ,&
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import org.hibernate.Session; M |?qSFv:
import org.hibernate.criterion.DetachedCriteria; #!rng]p
import org.hibernate.criterion.Projections; j/3827jw=
import AOWX=`J8V
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org.springframework.orm.hibernate3.HibernateCallback; ZJsc ?*@
import wfM$JYfI
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org.springframework.orm.hibernate3.support.HibernateDaoS c_}i(HQ
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upport; :y !e6
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import com.javaeye.common.util.PaginationSupport; :N\*;>
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public abstract class AbstractManager extends ?;,s=2
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HibernateDaoSupport { .a:"B\B`
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privateboolean cacheQueries = false; r1EccY
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privateString queryCacheRegion; ]p(+m_F
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publicvoid setCacheQueries(boolean x?KgEcnw2X
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cacheQueries){ *6e`km
this.cacheQueries = cacheQueries; JTNQz
} V;L^q?v
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publicvoid setQueryCacheRegion(String ~IZ'zuc
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queryCacheRegion){ k^J~l=?v
this.queryCacheRegion = )^
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queryCacheRegion; *GbC`X)
} # ,u7lAz
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publicvoid save(finalObject entity){ vvv~n]S6
getHibernateTemplate().save(entity); T2Z;)e$m_
} ]G1{@r)
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publicvoid persist(finalObject entity){ l?NRQTG
getHibernateTemplate().save(entity); *I`Sc|A
} "u Xl
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publicvoid update(finalObject entity){ 699z@>$}
getHibernateTemplate().update(entity); Z8(1QU,~2
} W tnZF]1:u
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publicvoid delete(finalObject entity){ rhMsZ={M
getHibernateTemplate().delete(entity); x6* {@J&5*
} kCL)F\v"iT
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publicObject load(finalClass entity, N)lzX X
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finalSerializable id){ m/|>4~
return getHibernateTemplate().load ]N NLr;p
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(entity, id); _Hl[Fit<j1
} Y]{<IF:
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publicObject get(finalClass entity, !(*mcYA*W
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finalSerializable id){ zPe4WE|
return getHibernateTemplate().get R/waWz\D
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(entity, id); P.gk'\<k
} (;$J5
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publicList findAll(finalClass entity){ 3Ku!;uo!u
return getHibernateTemplate().find("from ] ^tor
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" + entity.getName()); ve.iyr
} 8U/q3@EC
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publicList findByNamedQuery(finalString k.rP}76
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namedQuery){ sT[)r]`T
return getHibernateTemplate xoTS?7
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().findByNamedQuery(namedQuery); miCt)Qd
} k
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publicList findByNamedQuery(finalString query, ;j-@
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finalObject parameter){ R@5jEf
return getHibernateTemplate gAhCNOp
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().findByNamedQuery(query, parameter); S5@/;T
} B~cq T/\?
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publicList findByNamedQuery(finalString query, F:%= u
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finalObject[] parameters){ K7FuMB
return getHibernateTemplate },2-\-1
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().findByNamedQuery(query, parameters); W8,XSUl
} hmtRs]7
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publicList find(finalString query){ W,`u5gbT
return getHibernateTemplate().find J#L-Slav%
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(query); @CP"AYB #
}
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publicList find(finalString query, finalObject (ivV [
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parameter){ V5i_\A
return getHibernateTemplate().find QUaz;kNC7
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(query, parameter); X"(!\{ySI;
} 9xB^dKM3
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public PaginationSupport findPageByCriteria gd_w;{WP
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(final DetachedCriteria detachedCriteria){ xB68RQe)
return findPageByCriteria U;?%rM6
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); b+'G^!JR
} &vj+3<2
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public PaginationSupport findPageByCriteria G&0&*mp
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(final DetachedCriteria detachedCriteria, finalint r6Lb0PzMf
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startIndex){ K)]7e?:Wu
return findPageByCriteria S6 $S%$
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(detachedCriteria, PaginationSupport.PAGESIZE, r[eZV"
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startIndex); 8d-; ;V
} 25l6@7q.
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public PaginationSupport findPageByCriteria G#HbiVH9
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(final DetachedCriteria detachedCriteria, finalint ?Gp~i]
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pageSize, X@b$C~+
finalint startIndex){ :t(gD8 ;
return(PaginationSupport) b)en/mz
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getHibernateTemplate().execute(new HibernateCallback(){ YUF!Y9!
publicObject doInHibernate R9o:{U]
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(Session session)throws HibernateException { DGC-`z
Criteria criteria = Eg3rbqM- 8
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detachedCriteria.getExecutableCriteria(session); 5u:+hB
int totalCount = pCb@4nb
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((Integer) criteria.setProjection(Projections.rowCount Qf414 oW
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()).uniqueResult()).intValue();
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criteria.setProjection k)[} 3oq
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(null); !Wvzum@5D
List items = =gGK24 3
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criteria.setFirstResult(startIndex).setMaxResults *<x]gV
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(pageSize).list(); *-ZD -B*?
PaginationSupport ps = C@buewk
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new PaginationSupport(items, totalCount, pageSize, e[ i&2mM
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startIndex); go]d+lhFB
return ps; |^S[Gr w
} gET& +M
}, true); ]b'K
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} Fz?ON1\
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public List findAllByCriteria(final $P^=QN5Bb
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DetachedCriteria detachedCriteria){ Y3-Tg~/~W
return(List) getHibernateTemplate eoR@5OA&
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().execute(new HibernateCallback(){ K>RL
publicObject doInHibernate CUnZ}@?d
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(Session session)throws HibernateException { C0 .Xp
Criteria criteria = c500:OSB
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detachedCriteria.getExecutableCriteria(session); B6 x5E
return criteria.list(); {AO3o<-h
} |QAmN>7U
}, true); 8<^[xe
} zO2<Igb
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public int getCountByCriteria(final bsr
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DetachedCriteria detachedCriteria){ r4J4|&ym
Integer count = (Integer) #E^ %h
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getHibernateTemplate().execute(new HibernateCallback(){ pA4/'7nCl
publicObject doInHibernate xE9^4-Px*
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(Session session)throws HibernateException { $
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Criteria criteria = ^dZ,Itho
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detachedCriteria.getExecutableCriteria(session); >Eik>dQ a
return HjGT{o
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criteria.setProjection(Projections.rowCount ^P"t
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()).uniqueResult(); BR*""/3`
} $]|_xG-6{
}, true); R
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return count.intValue(); y|.wL=;
} xW/JItF
} 5c{=/}Y
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用户在web层构造查询条件detachedCriteria,和可选的 O5_E"um
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 |1J "r.K
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PaginationSupport的实例ps。 .a;-7|x
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ps.getItems()得到已分页好的结果集 * fSa8CV
ps.getIndexes()得到分页索引的数组 }9Y='+.%^
ps.getTotalCount()得到总结果数 ~`*:E'/5k]
ps.getStartIndex()当前分页索引 F:hJ^:BP
ps.getNextIndex()下一页索引 DMfC(w.d
ps.getPreviousIndex()上一页索引 r\_rnM)_xN
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 _32ltnBX
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 A.35WGu&:
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一下代码重构了。 oS_'@u.5
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我把原本我的做法也提供出来供大家讨论吧: 86R}G/>>e
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首先,为了实现分页查询,我封装了一个Page类: eZ}FKg%2[
java代码: G <Lm}
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/*Created on 2005-4-14*/ _AVCh)Zb
package org.flyware.util.page; I*K^,XY+
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/** pC5-,Z;8
* @author Joa `q$DNOrS
* f8[2$i*cL
*/ Plm3vk=
publicclass Page { |7|mnOBdDf
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/** imply if the page has previous page */ dN\pe@#lKP
privateboolean hasPrePage; '\_ic=&u
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/** imply if the page has next page */ yv$MQ~]
privateboolean hasNextPage; Hsp|<;Yg
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/** the number of every page */ qn+m lduU
privateint everyPage; 35&&*$Jm
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/** the total page number */ >V;<K?5B`W
privateint totalPage; t{?_]2vl
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/** the number of current page */ oL VtP
privateint currentPage; azE>uEsE
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/** the begin index of the records by the current K
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query */ D+ jk0*bJ
privateint beginIndex; {qOSs,+=L
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