Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 rcc.FS
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 NNWbbU3wjh
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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 X%+FM]
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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 {H$F!}a
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分页支持类: =4RBHe8`
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java代码: <h_lc}o/
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package com.javaeye.common.util; u9AXiv+K
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import java.util.List; m"B)%?C#
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publicclass PaginationSupport { 5t$ZEp-
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publicfinalstaticint PAGESIZE = 30; 8aCa(Xu(H
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privateint pageSize = PAGESIZE; #S[:Q.0 ;
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privateList items; J~Gq#C^e
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privateint totalCount; .Gq)@{o>
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privateint[] indexes = newint[0]; "RuH"~o
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privateint startIndex = 0; ]xf
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public PaginationSupport(List items, int Qtmsk:qm
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totalCount){ _7SOl.5ZE
setPageSize(PAGESIZE); M) 9Ss
setTotalCount(totalCount); RRaGc )B
setItems(items); {nH.
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setStartIndex(0); JGaS`fKSk
} Sr_]R<?
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public PaginationSupport(List items, int *Z7W'-
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totalCount, int startIndex){ l?_Iu_Qp
setPageSize(PAGESIZE); saOXbt(&
setTotalCount(totalCount); ;0V{^
setItems(items); @] .Ko[P~
setStartIndex(startIndex); X*F#=.lh
} }U$Yiv
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public PaginationSupport(List items, int N|eus3\E
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totalCount, int pageSize, int startIndex){ CT6Ca,
setPageSize(pageSize); S#{e@ C
setTotalCount(totalCount); M%f96XUM
setItems(items); i(q%EMf
setStartIndex(startIndex); H*_:IfI!
} sL;qC\S
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publicList getItems(){ Bb];qYuCO
return items; 'xAfcP[^
} clQN@1] M
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publicvoid setItems(List items){ /?l@7
this.items = items; P@'<OI
} RE]u2R6Y
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publicint getPageSize(){ s OD>mc#%Y
return pageSize; _yTGv-
} ' } rUbJo
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publicvoid setPageSize(int pageSize){ z65|NO6JW.
this.pageSize = pageSize; SP9_s7LL
} x72bufd
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publicint getTotalCount(){ '+BcPB?E
return totalCount; \H+/D &M
} 4os7tx
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publicvoid setTotalCount(int totalCount){ ^B2>lx\n
if(totalCount > 0){ E1:{5F5/
this.totalCount = totalCount; b,YTw
int count = totalCount / sW 7R&t!G
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pageSize; vX})6O
if(totalCount % pageSize > 0) I.I:2Ew+
count++; &eq>>
indexes = newint[count]; v\ggFrG]
for(int i = 0; i < count; i++){ <Yfk7Un
indexes = pageSize * XA}!
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} %fMK^H8{
}else{ djV^A
this.totalCount = 0; +\G/j ]3f
} _wp6rb:8!
} zN JK+_O=
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publicint[] getIndexes(){ siw }
}}
return indexes; > Zo_-,
} ~}|)@,N'bm
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publicvoid setIndexes(int[] indexes){ %qRbl4
this.indexes = indexes; Sf[ZGY)
} ,EW-21
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publicint getStartIndex(){ zC6,m6Dv
return startIndex; MIasCH>r
} 'mj0+c$
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publicvoid setStartIndex(int startIndex){ j}Lt"r2F
if(totalCount <= 0) |xyN#wi
this.startIndex = 0; JnH>L|G{;%
elseif(startIndex >= totalCount) 1Qui.],c
this.startIndex = indexes PiXegh WH
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[indexes.length - 1]; |XOD~Plo^
elseif(startIndex < 0) cP63q|[[
this.startIndex = 0; j?4k{?x
else{ W!4(EdT*Cq
this.startIndex = indexes E[HXbj"
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[startIndex / pageSize]; #R<4K0Xan
} Epsc2TuH7
} s2)a8<
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publicint getNextIndex(){ *[@lp7
int nextIndex = getStartIndex() + a+ZP]3@
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pageSize; i ]gF
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if(nextIndex >= totalCount) L=ZKY
return getStartIndex(); K.G}*uy
else F`-|@k
return nextIndex; w;}pebL:
} Q~<$'j
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publicint getPreviousIndex(){ wQJY,|.
int previousIndex = getStartIndex() - A~&Tp
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pageSize; "P`V|g
if(previousIndex < 0) F)g.CDQ!c
return0; 4-z3+e
else fgYdKv8
return previousIndex; '}4LHB;:
} @V:4tG.<sw
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} c*$&MCh
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抽象业务类 Q9=vgOW+
java代码: ),y{.n:wm
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/** IM),cOp=
* Created on 2005-7-12 >u#c\s
*/ S83wAr9T
package com.javaeye.common.business; ;g$s`l/
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import java.io.Serializable; YpMQY-n
import java.util.List; &NiDv
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import org.hibernate.Criteria; VqV6)6
import org.hibernate.HibernateException; '>-
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import org.hibernate.Session; 26 un=
import org.hibernate.criterion.DetachedCriteria; 0@z=0}0Z
import org.hibernate.criterion.Projections; :{?8rA5
import C5m6{Oo+-
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org.springframework.orm.hibernate3.HibernateCallback; CJ0j2e/
import ujsJ;\c
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org.springframework.orm.hibernate3.support.HibernateDaoS @/i{By^C
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upport; ;i?Ao:]
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import com.javaeye.common.util.PaginationSupport; ~Q%C>
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public abstract class AbstractManager extends GY 4?}T^s
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HibernateDaoSupport { q@1!v
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privateboolean cacheQueries = false; 3D70`u
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privateString queryCacheRegion; v+ dt1;
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publicvoid setCacheQueries(boolean 1~NXCIdF
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cacheQueries){ 8" l9W=
this.cacheQueries = cacheQueries; g
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} L9[? qFp
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publicvoid setQueryCacheRegion(String ku q3QW<
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queryCacheRegion){ {tn%HK">
this.queryCacheRegion = .6S]\dp7~
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queryCacheRegion; zB`)\
} xB"o
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publicvoid save(finalObject entity){ w
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getHibernateTemplate().save(entity); L/9f"%kZ
} yE L^Y'x?
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publicvoid persist(finalObject entity){ Qag@#!&n
getHibernateTemplate().save(entity); E8#r<=(m
} so_
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publicvoid update(finalObject entity){ i9fK`:)
getHibernateTemplate().update(entity); %toxZ}OP
} "Wd?U[[
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publicvoid delete(finalObject entity){ 4jEPh{q
getHibernateTemplate().delete(entity); j&) "a,f
} 6KP"F[8I
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publicObject load(finalClass entity, 4h wUH
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finalSerializable id){ &qqS'G*
return getHibernateTemplate().load Uv'.]#H<
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(entity, id); *l:5FTp
} \AV6;;}&
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publicObject get(finalClass entity, Z=`\U?,
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finalSerializable id){ H@Dj$U
return getHibernateTemplate().get ;,GE!9HW
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(entity, id); eED Fm
} %IG cn48J
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publicList findAll(finalClass entity){ Mo`7YS-Y
return getHibernateTemplate().find("from * Zb-YA
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" + entity.getName()); RGy4p)z*+
} %Z?2.)
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publicList findByNamedQuery(finalString Vh1{8'GQ
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namedQuery){ }ybveZxv5A
return getHibernateTemplate @+1-_Q`s/R
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().findByNamedQuery(namedQuery); v7"' ^sZ?
} Wi ]Mp7b
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publicList findByNamedQuery(finalString query, sLh9=Kh`
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finalObject parameter){ gd3~R+Kd
return getHibernateTemplate `ro~l_U;A
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().findByNamedQuery(query, parameter); r<4FF=
} +BcJHNIB
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publicList findByNamedQuery(finalString query, 7N0V`&}T
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finalObject[] parameters){ . zf#S0y%(
return getHibernateTemplate aV3:wp]Gn
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().findByNamedQuery(query, parameters); a!YpSFr
} mD`v>L
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publicList find(finalString query){ m }I@:s2
return getHibernateTemplate().find '&4W@lvyz
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(query); ;~Y0H9`
} D>wq4u
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publicList find(finalString query, finalObject Cw "Y=`
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parameter){ 8/cD7O
return getHibernateTemplate().find Y(QLlJ*)/
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(query, parameter); u'}SaX]0
} m3zmyw}
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public PaginationSupport findPageByCriteria kd^CZ;O
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(final DetachedCriteria detachedCriteria){ *|S.[i_7
return findPageByCriteria `!{m#BBT}
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); #hPa:I$Oc
} A?I/[zkc
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public PaginationSupport findPageByCriteria 5*QNE!
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(final DetachedCriteria detachedCriteria, finalint R B7?T5G
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startIndex){ ?g*#ld()
return findPageByCriteria /y/O&`X(
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(detachedCriteria, PaginationSupport.PAGESIZE, )i@j``P
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startIndex); =8BMCedH|
} $S{B{FK
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public PaginationSupport findPageByCriteria }S84^2J_
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(final DetachedCriteria detachedCriteria, finalint CD|)TXy
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pageSize, $|~YXH~O
finalint startIndex){ f?)BAah
return(PaginationSupport) y>}dKbCN
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getHibernateTemplate().execute(new HibernateCallback(){ )Zx;Z[
publicObject doInHibernate #P[d?pY
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(Session session)throws HibernateException { ~"-+BG(5
Criteria criteria = >
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detachedCriteria.getExecutableCriteria(session); O3,IR1
int totalCount = :=
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((Integer) criteria.setProjection(Projections.rowCount HPM
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()).uniqueResult()).intValue(); ;Y<Hi\2oy
criteria.setProjection Ak(_![Q:q\
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(null); yTj!(C
List items = .Y!]{c
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criteria.setFirstResult(startIndex).setMaxResults OhUEp g[
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(pageSize).list(); 9I3vW]0x[
PaginationSupport ps = ,S.<qmf
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new PaginationSupport(items, totalCount, pageSize, J'99
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startIndex); 9C;Hm>WEpP
return ps; 'n1-?T)
} QkMK\Up
}, true); 72J@Dc
} Y`$dtg {
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public List findAllByCriteria(final qfF/X"#0
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DetachedCriteria detachedCriteria){ NCm>iEeY
return(List) getHibernateTemplate xw2dEvjgp%
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().execute(new HibernateCallback(){ u#TRm?s
publicObject doInHibernate v/ dyu
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(Session session)throws HibernateException { (J!FW(Ma|=
Criteria criteria = =3KK/[2M
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detachedCriteria.getExecutableCriteria(session); &OpGcbf1
return criteria.list(); Ur^~fW1o
} 6 <&jY
}, true); t^N
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} a>w@9
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public int getCountByCriteria(final z
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DetachedCriteria detachedCriteria){ z@WuKRsi
Integer count = (Integer) 'rWu}#Nb
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getHibernateTemplate().execute(new HibernateCallback(){ !VNLjbee.
publicObject doInHibernate Vn:BasS%
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(Session session)throws HibernateException { QL_~E;U
Criteria criteria =
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detachedCriteria.getExecutableCriteria(session); kJ^)7_3
return mM*jdm(!
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criteria.setProjection(Projections.rowCount
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()).uniqueResult(); 0MV^-M
} 3I|&}+Z6
}, true); 4}mp~AXy;z
return count.intValue(); :z=C
} /$]#L%
} a(|YLN
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用户在web层构造查询条件detachedCriteria,和可选的 m|tE3UBNv
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ;W ZA
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PaginationSupport的实例ps。 jlhyn0
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ps.getItems()得到已分页好的结果集 <p_r{
ps.getIndexes()得到分页索引的数组 1_chO?&,I
ps.getTotalCount()得到总结果数 z^tws*u],5
ps.getStartIndex()当前分页索引 #g)$m}tv?
ps.getNextIndex()下一页索引 HiTn 5XNf
ps.getPreviousIndex()上一页索引 :g1C,M~
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 cP >MsUZWl
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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 *k&yD3br-V
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一下代码重构了。 H.sYy-_]F
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我把原本我的做法也提供出来供大家讨论吧: #bFJ6;g=V
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首先,为了实现分页查询,我封装了一个Page类: [^iQE
java代码: >U.)?>G/dt
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/*Created on 2005-4-14*/ ROWb:tX}
package org.flyware.util.page; w!~%v
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/** RR*eq.;
* @author Joa @-uV6X8|
* )3W`>7>
*/ BvXA9YQ3
publicclass Page { D1Yc_
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/** imply if the page has previous page */ -2)6QKh~D
privateboolean hasPrePage; !/1aot^(
*'b3Z3c,;
/** imply if the page has next page */ &&(^;+
privateboolean hasNextPage; v]"W.<B,
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/** the number of every page */ m@|0iDS
privateint everyPage; ;<aT|4
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/** the total page number */ M qy5>f)
privateint totalPage; |sQC:y>
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/** the number of current page */ hJuR,NP
privateint currentPage; \KBE+yj
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/** the begin index of the records by the current O8&