Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 bQQVj?8jp
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 mEDpKWBk
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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 R$6qoqv{yG
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 w~+ aW(2
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分页支持类: p538r[f<
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java代码: pP.'wSj
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package com.javaeye.common.util; = `t^~.5
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import java.util.List; ;j'Daupt;=
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publicclass PaginationSupport { x';uCKWV
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publicfinalstaticint PAGESIZE = 30; jP=Hf=:$
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privateint pageSize = PAGESIZE; n-afDV
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privateList items; AW8'RfC.
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privateint totalCount; G+WM`:v8%
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privateint[] indexes = newint[0]; ;y1Q6eN
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privateint startIndex = 0; ,=PKd&
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public PaginationSupport(List items, int QLo(i
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totalCount){ l-O$ m
setPageSize(PAGESIZE); JUt7En;XE
setTotalCount(totalCount); rAukHeH
setItems(items); Qn+:/zA;
setStartIndex(0); &M[f&_"8Q
} MXZ>"G
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public PaginationSupport(List items, int w{,4rk;Hr
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totalCount, int startIndex){ ?Rr2/W#F
setPageSize(PAGESIZE); :td ~g;w
setTotalCount(totalCount); QMp rv*i
setItems(items); E^V|
setStartIndex(startIndex); 1mgLX_U9
} !a-b6Aa
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public PaginationSupport(List items, int 5ukp^OxE
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totalCount, int pageSize, int startIndex){ k*Nr!Z!}
setPageSize(pageSize); .#w6%c@
setTotalCount(totalCount); ERz;H!pU8
setItems(items); i*[n{=*l@
setStartIndex(startIndex); R.RSQk7;
} $:bih4@>
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publicList getItems(){ 2U$"=:Cf
return items; +l0g`:
} `DW2spd
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publicvoid setItems(List items){ /n{1o\
this.items = items; I0Ia6w9
} m,MSMw1p
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publicint getPageSize(){ AR&:Q4r|
return pageSize; <nHkg<O6Y
} N$I03m
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publicvoid setPageSize(int pageSize){ .zj0Jy8N
this.pageSize = pageSize; /@oLe[Mz$
} X@wm1{!
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publicint getTotalCount(){ FY'dJY3O
return totalCount; B(5c9DI`
} x?,9_va]
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publicvoid setTotalCount(int totalCount){ p.K*UP
if(totalCount > 0){ )}lRd#V
this.totalCount = totalCount; G=/k>@Di
int count = totalCount / |(R5e
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pageSize; LF<wt2?*
if(totalCount % pageSize > 0) &9[P-w;7u
count++; 6z,Dyy]tl
indexes = newint[count]; Z*!O:/B
for(int i = 0; i < count; i++){ RrV>r<Z"Q
indexes = pageSize * )0 Z! n
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} mLbN/M
}else{ _S?qDG{E|
this.totalCount = 0; p.JXSn
} &Z("D7.G
} ixfdO\nU
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publicint[] getIndexes(){ |F$BvCg
return indexes; " {dek
} Q(7ob}+jQ
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publicvoid setIndexes(int[] indexes){ Sr Ca3PA
this.indexes = indexes; R`'1t3p0i
} /8yn vhF#
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publicint getStartIndex(){ Jl<ns,Zg
return startIndex; D)$8W[
} k%'m *T f
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publicvoid setStartIndex(int startIndex){ TV59(bG.2
if(totalCount <= 0) Do7=#|bAM
this.startIndex = 0; c@(&[/q!
elseif(startIndex >= totalCount) L1m{]>{-
this.startIndex = indexes GRqT-/n"
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[indexes.length - 1]; O'*@ Ytn
elseif(startIndex < 0) )Di \_/G
this.startIndex = 0; ,yMU@Vg
else{ TbVn6V'
this.startIndex = indexes _Q(g(p&
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[startIndex / pageSize]; B~o-l*
} s 0u{dqP
} 8P' ana
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publicint getNextIndex(){ Vy<HA*
int nextIndex = getStartIndex() + @p=AWi}\
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pageSize; DPn=n9n2
if(nextIndex >= totalCount) cu!W4Ub<
return getStartIndex(); Rf-[svA
else Y4.Eq+$gh
return nextIndex; E-5_{sc
} vdDludEv
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publicint getPreviousIndex(){ o|pT;1a"
int previousIndex = getStartIndex() - u+t$l^S
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pageSize; K4Dp:2/K%
if(previousIndex < 0) 58xnB!h\}
return0; %^.%OCX:
else fl\aqtF
return previousIndex; "Ml&[Oge
} qml2XJ>
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} gR^>3n'
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抽象业务类 QYb33pN|
java代码: #:x4DvDkR
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/** .9[45][FK
* Created on 2005-7-12 <+#oBN
*/ ^rl"rEA
package com.javaeye.common.business; FXdD4 X)
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import java.io.Serializable; lS^(&<{
import java.util.List; ,tH5e&=U01
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import org.hibernate.Criteria; y4:H3Sk
import org.hibernate.HibernateException; (UCK;k
import org.hibernate.Session; #3=P4FUz.
import org.hibernate.criterion.DetachedCriteria; x]mxD|?f
import org.hibernate.criterion.Projections; GV6K/T:
import zjL.Bhiud
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org.springframework.orm.hibernate3.HibernateCallback; $2DuB
import 5F|8?BkOL^
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org.springframework.orm.hibernate3.support.HibernateDaoS JPM))4YDR
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upport; g42)7
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import com.javaeye.common.util.PaginationSupport; CRve.e8J
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public abstract class AbstractManager extends YKbCdLQ
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HibernateDaoSupport { 7?gFy-
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privateboolean cacheQueries = false; gG%V 9eOQ
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privateString queryCacheRegion; I\?9+3 XnQ
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publicvoid setCacheQueries(boolean 8l?piig#
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cacheQueries){ pu!d qF<
this.cacheQueries = cacheQueries; q{2I_[p
} dUgrKDNyA
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publicvoid setQueryCacheRegion(String rdnno
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queryCacheRegion){ j#~Jxv%n
this.queryCacheRegion = \7MHaQvS
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queryCacheRegion; ~m1P_`T
} be5,U\&z
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publicvoid save(finalObject entity){ b 6t}{_7
getHibernateTemplate().save(entity); .,~(%#Wl$
} rPc7(,o*
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publicvoid persist(finalObject entity){ }~h'FHCC+
getHibernateTemplate().save(entity); ri C[lB
} S.B<pjgt
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publicvoid update(finalObject entity){ {:c]|^w6
getHibernateTemplate().update(entity);
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} 2eeQ@]Wj[Z
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publicvoid delete(finalObject entity){ b,P ]9$Ut
getHibernateTemplate().delete(entity); *'"T$ib
}
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publicObject load(finalClass entity, |8%m.fY`
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finalSerializable id){ xX0-]Y h:
return getHibernateTemplate().load <)g8yA
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(entity, id); p
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} c/L>>t
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publicObject get(finalClass entity, nI*/Mhx
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finalSerializable id){ KPSh#x&I
return getHibernateTemplate().get *?QE2&S:
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(entity, id); z|G9,:9
} nfb]VN~(
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publicList findAll(finalClass entity){ -Z4{;I[Q@
return getHibernateTemplate().find("from 0Q"u#V Sp
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" + entity.getName()); IUGz =%[
} NRnRMY-
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publicList findByNamedQuery(finalString jO9ip
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namedQuery){
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return getHibernateTemplate 2y0J`!/)
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().findByNamedQuery(namedQuery); A]`El8_t"
} BhpOXqg
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publicList findByNamedQuery(finalString query, "`}~~.q
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finalObject parameter){ z!=P@b
return getHibernateTemplate M"q[ p
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().findByNamedQuery(query, parameter); J MX6yV
} B;Nl~Y| \
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publicList findByNamedQuery(finalString query, W]<$0
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finalObject[] parameters){ Vi!Q
return getHibernateTemplate 3zuF{Q2P<
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().findByNamedQuery(query, parameters); h*0S$p<[1
} |6biq8|$3V
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publicList find(finalString query){ CR4rDh8z a
return getHibernateTemplate().find y#ON|c
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(query); ;N+$2w
} dYFzye
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publicList find(finalString query, finalObject fi PIAT}
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parameter){ ?{o/I\\
return getHibernateTemplate().find [~5p>'
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(query, parameter); -y) ,Y
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} l2v_?j-)x
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public PaginationSupport findPageByCriteria Hyk'c't_O
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(final DetachedCriteria detachedCriteria){ !.-tW7
return findPageByCriteria ]>##`X
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(detachedCriteria, PaginationSupport.PAGESIZE, 0);
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} -P=g3Q i
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public PaginationSupport findPageByCriteria x!S;SU
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(final DetachedCriteria detachedCriteria, finalint O/AE}]
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startIndex){ k@!r#`j3
return findPageByCriteria 4YG/`P
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(detachedCriteria, PaginationSupport.PAGESIZE, F
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startIndex); R5Yl 1
} H(+<)qH
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public PaginationSupport findPageByCriteria D _X8-
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(final DetachedCriteria detachedCriteria, finalint 9pWy"h$H
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pageSize, suJ_nb
finalint startIndex){ `qpc*enf0
return(PaginationSupport) MKGS`X]<J
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getHibernateTemplate().execute(new HibernateCallback(){ Q}%tt=KD
publicObject doInHibernate $FM'
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(Session session)throws HibernateException { ^~ =9
Criteria criteria = E,G<_40
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detachedCriteria.getExecutableCriteria(session); ucYkxi`x
int totalCount = IxSV? k
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((Integer) criteria.setProjection(Projections.rowCount Rz <OF^Iy
+}7fg82)
()).uniqueResult()).intValue(); n"{X!(RIcx
criteria.setProjection To"dG&h
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(null); oT+(W,G
List items = }F1s
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criteria.setFirstResult(startIndex).setMaxResults }Ag|gF!_
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(pageSize).list(); 1IH[g*f
PaginationSupport ps = </oY4$ l'
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new PaginationSupport(items, totalCount, pageSize, G"s0GpvQ
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startIndex); r((Tavn
return ps; :Z`4j
} c,5n,i
}, true); $N+6h#
} z MdC
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public List findAllByCriteria(final 2=*=^)FNI
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DetachedCriteria detachedCriteria){ 97~K!'/^+y
return(List) getHibernateTemplate W^g'}}]T
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().execute(new HibernateCallback(){ M=!i>(yG
publicObject doInHibernate T{MC-j _T9
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(Session session)throws HibernateException { 'w<BJTQIL
Criteria criteria = jp<VK<s]
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detachedCriteria.getExecutableCriteria(session); -e`;bX_N)
return criteria.list(); -f>'RI95>
} zhEo(kU!
}, true); cy3ww})
} ziL^M"~2
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public int getCountByCriteria(final <)#kq1b?
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DetachedCriteria detachedCriteria){ 4,1oU|fz
Integer count = (Integer) 1M5 -pZ[D
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getHibernateTemplate().execute(new HibernateCallback(){ /A(NuB<Pq
publicObject doInHibernate hw,^G5m
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(Session session)throws HibernateException { (Pi-uL<[a
Criteria criteria = Q7Ij4
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detachedCriteria.getExecutableCriteria(session); Q_P5MLU>
return F-0UdV
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criteria.setProjection(Projections.rowCount 'F_}xMU
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()).uniqueResult(); QlzQ]:dWC
} F,}s$v
}, true); [%8@DC'
return count.intValue(); 'V!kL,
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} } p'8w\C$
} 9N
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用户在web层构造查询条件detachedCriteria,和可选的 h5onRa*7
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 UC!5
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PaginationSupport的实例ps。 iHz[Zw^.s
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ps.getItems()得到已分页好的结果集 Nlt4)
ps.getIndexes()得到分页索引的数组 YFx=b!/s
ps.getTotalCount()得到总结果数 :XS"#^aJ
ps.getStartIndex()当前分页索引 Dd/}Ya(Gi
ps.getNextIndex()下一页索引 h~ha
ps.getPreviousIndex()上一页索引 rSyaZ6#
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 &%e"9v2`
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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 U42\.V0
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一下代码重构了。 q<XcOc5
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我把原本我的做法也提供出来供大家讨论吧: s/S+ ec3
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首先,为了实现分页查询,我封装了一个Page类: 1URsHV!xcM
java代码: bOXh|u_3i
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/*Created on 2005-4-14*/ `@$YlFOW
package org.flyware.util.page; Ihef$,
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/** n4*'B*
* @author Joa n\~yX<;X3
* m|dF30~A
*/
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publicclass Page { CjZ6NAHc
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/** imply if the page has previous page */ >@Khm"/T
privateboolean hasPrePage; JS2!)aqc
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/** imply if the page has next page */ 6QptKXu7
privateboolean hasNextPage; EG1x
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/** the number of every page */ rxkBg0Z`a
privateint everyPage; mt .,4
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/** the total page number */ o}R|tOe
privateint totalPage; :eLLDp<
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/** the number of current page */ }q x(z^
privateint currentPage; D4\(:kF\Hg
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/** the begin index of the records by the current nK:`e9ES
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query */ \]GGVI;u
privateint beginIndex; "b;k.Fx
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/** The default constructor */ s.ey!ew
public Page(){ ^ N_`^m
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} RA~_]Hk
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/** construct the page by everyPage /K&