Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 u~:y\/Y6
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 F,F4nw<W
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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 ?=7cF
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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 :pY/-Cgv
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分页支持类: U}[d_f
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java代码: UhWNl]Z
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package com.javaeye.common.util;
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import java.util.List; {4}yKjW%z
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publicclass PaginationSupport { >8^
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publicfinalstaticint PAGESIZE = 30; {6|G@""O
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privateint pageSize = PAGESIZE; HZB>{O
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privateList items; aiUY>M#|
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privateint totalCount; (t
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privateint[] indexes = newint[0];
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privateint startIndex = 0; }'V5/>m[
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public PaginationSupport(List items, int (Z q/
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totalCount){ N^G
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setPageSize(PAGESIZE); J?1 uKR
setTotalCount(totalCount); ::lKL
setItems(items); wu!59pL
setStartIndex(0); bHYy }weZ
} X/!o\yyT
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public PaginationSupport(List items, int [Td4K.c
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totalCount, int startIndex){ 6r0krbN
setPageSize(PAGESIZE); %D34/=(X
setTotalCount(totalCount); {SPq$B_VR
setItems(items); Oc#syfO
setStartIndex(startIndex); tjGn|+|k
} l"T44CL;
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public PaginationSupport(List items, int +F` S>U
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totalCount, int pageSize, int startIndex){ z&)A,ryW0
setPageSize(pageSize); OA1uY83"
setTotalCount(totalCount); T^t#
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setItems(items); drP=A~?&:
setStartIndex(startIndex); %QGC8Tz
} m+R[#GE8#
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publicList getItems(){ B$ PP&/
return items; &MQmu,4
} )h4f\0
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publicvoid setItems(List items){ Xm}/0g&7
this.items = items; jDfC=a])
} _\G"9,)u'
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publicint getPageSize(){ nZyX|SPk
return pageSize; HY*Kb+[
} Y@vTaE^w3
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publicvoid setPageSize(int pageSize){ a=9:[
this.pageSize = pageSize; W?R6ZAn
} 4<Utmr
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publicint getTotalCount(){ !4RWYMV"
return totalCount; Gbr=+AT
} GL#u p
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publicvoid setTotalCount(int totalCount){ mbxZL<ua
if(totalCount > 0){ h$>-.-
this.totalCount = totalCount; 9gDkTYkj
int count = totalCount / b\kdKVh&
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pageSize; f!uw zHA`?
if(totalCount % pageSize > 0) xd?f2=dd~h
count++; W)2p@j59A
indexes = newint[count]; b9J_1Gl]
for(int i = 0; i < count; i++){ jh%Eq+#S
indexes = pageSize * ,{u
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} @ $ ;q;
}else{ ]d0BN`*U.
this.totalCount = 0; ^R7lom.
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} /wEhVR`=
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publicint[] getIndexes(){ X::JV7hu
return indexes; E)5\i-n
} *20jz<
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publicvoid setIndexes(int[] indexes){ IqaT?+O\?r
this.indexes = indexes; {yHCXFWlS
} C=L>zOZ
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publicint getStartIndex(){ Bi 3<7
return startIndex; g0=z&2Q[_)
} P|tO<t6/9*
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publicvoid setStartIndex(int startIndex){ KE5kOU;
if(totalCount <= 0) 1~Y<//5E
this.startIndex = 0; qpP=K $
elseif(startIndex >= totalCount) {9&;Q|D z
this.startIndex = indexes
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[indexes.length - 1]; i(%W_d!
elseif(startIndex < 0) 2^[`e g
this.startIndex = 0; TOB-aAO
else{ I(L,8n5
this.startIndex = indexes J s@hLP`
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[startIndex / pageSize]; )Xz,j9GzJS
} rxvx
} s 8jV(P(O
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publicint getNextIndex(){ _ @NL;w:!
int nextIndex = getStartIndex() + kzQ+j8.,U
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pageSize; s^G.]%iU
if(nextIndex >= totalCount) A@!qv#'
return getStartIndex(); 45@ I *`
else -8ywO"6
return nextIndex; oi&VgnSk
} HSE!x_$
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publicint getPreviousIndex(){ EPI4!3]
int previousIndex = getStartIndex() - #C74z$
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pageSize; ["k,QX
if(previousIndex < 0) i/;\7n
return0; Q0`wt.}V2
else / |;RV"
return previousIndex; _lJ!R:*
} {Qf=G|Ah
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} FF`T\&u
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抽象业务类 K,;E5
java代码: ~tS Z%q
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/** L2[($l
* Created on 2005-7-12 2+N]PW\V
*/ Uou1mZz/
package com.javaeye.common.business; XSwl Tg
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import java.io.Serializable; [\98$BN
import java.util.List; ?DS@e@lx
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import org.hibernate.Criteria; T?CdZc.
import org.hibernate.HibernateException; F`9xVnK=
import org.hibernate.Session; %ufN8w!p
import org.hibernate.criterion.DetachedCriteria; Af~$TyX
import org.hibernate.criterion.Projections; t:x\kp
import b;B%q$sntC
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org.springframework.orm.hibernate3.HibernateCallback; 9IdA%RM~mH
import \$~|ZwV{
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org.springframework.orm.hibernate3.support.HibernateDaoS !7O+ogL
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upport; vFzRg5lH
} ^~F|
import com.javaeye.common.util.PaginationSupport; !I{0 _b{
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public abstract class AbstractManager extends hn7#
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HibernateDaoSupport { P+
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privateboolean cacheQueries = false; J\}twYty
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privateString queryCacheRegion; hlvK5Z
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publicvoid setCacheQueries(boolean x$A+lj]x
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cacheQueries){ n:I,PS0H<
this.cacheQueries = cacheQueries; c)6m$5]
} fZGX}T<)p-
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publicvoid setQueryCacheRegion(String kUL'1!j7
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queryCacheRegion){ Y#ap*
this.queryCacheRegion = zJKv'>?
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queryCacheRegion; P[G)sA_"
} kf\PioD8
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publicvoid save(finalObject entity){ b"<liGh"n-
getHibernateTemplate().save(entity); #X+JHl
} T8?Ghbn
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publicvoid persist(finalObject entity){ ;RZ )
getHibernateTemplate().save(entity); Di,^%
} P8OaoPj
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publicvoid update(finalObject entity){ \S `:y?[Y
getHibernateTemplate().update(entity); y;m|
} "=HA Y
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publicvoid delete(finalObject entity){ w8")w*9Lmg
getHibernateTemplate().delete(entity); 9d0@wq.
} =g7x'
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publicObject load(finalClass entity, gs^Xf;gvI
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finalSerializable id){ ]\-A;}\e
return getHibernateTemplate().load ch*8B(:
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(entity, id); { T/[cu<
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publicObject get(finalClass entity, 3,_aAgeE
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finalSerializable id){ W<h)HhyG
return getHibernateTemplate().get k&M;,e3v6
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(entity, id); f=+mIZ
} JMCKcZ%N
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publicList findAll(finalClass entity){ .r=4pQ@#
return getHibernateTemplate().find("from ?>9/#Nv
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} <q58uuK
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publicList findByNamedQuery(finalString ^x ]r`b
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namedQuery){ Po+.&7F
return getHibernateTemplate X;+sUj8
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().findByNamedQuery(namedQuery); a
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} RT4x\&q
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publicList findByNamedQuery(finalString query, Qab>|eSm
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finalObject parameter){ -u+vJ6EY
return getHibernateTemplate Xz6<lLb
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().findByNamedQuery(query, parameter); l ~"^7H?4e
} 3GYw+%Z]
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publicList findByNamedQuery(finalString query, {f_={k
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finalObject[] parameters){ 5+4IN5o]=
return getHibernateTemplate %@J.{@>
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().findByNamedQuery(query, parameters); a@K%06A;'
} R`5.[?Dt
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publicList find(finalString query){ ;J( 8
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return getHibernateTemplate().find V;VHv=9`o
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(query); 94`7a<&ZNL
} ](]i 'fE>
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publicList find(finalString query, finalObject BGZ#wru
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parameter){ gT{Q#C2Baw
return getHibernateTemplate().find x
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(query, parameter); #b}Z`u?@
} _IHV7*u{;
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public PaginationSupport findPageByCriteria >0y'Rgfe
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(final DetachedCriteria detachedCriteria){ _#E0g'3
return findPageByCriteria :wyno#8`-
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); \##zR_%
} .bl/*s
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public PaginationSupport findPageByCriteria yf.~XUk^
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(final DetachedCriteria detachedCriteria, finalint #4NaL
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startIndex){ F@jZ ho
return findPageByCriteria VR 8-&N
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(detachedCriteria, PaginationSupport.PAGESIZE, GT.,
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startIndex); dm0R[[ 7
} yx8z4*]kH
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public PaginationSupport findPageByCriteria :A_@,Q
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(final DetachedCriteria detachedCriteria, finalint WM$
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finalint startIndex){ ;u
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return(PaginationSupport) OX0%C.K)hZ
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getHibernateTemplate().execute(new HibernateCallback(){ =U9*'EFr
publicObject doInHibernate &vMb_;~B
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(Session session)throws HibernateException { r.&Vw|*>
Criteria criteria = ? pmHFlx
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detachedCriteria.getExecutableCriteria(session); X=&ET)8-Y
int totalCount = [=q1T3
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((Integer) criteria.setProjection(Projections.rowCount 1W
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()).uniqueResult()).intValue(); wH&!W~M
criteria.setProjection *I.f1lz%*
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(null); >z>!Luw
List items = '3fu
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criteria.setFirstResult(startIndex).setMaxResults :J@gmY:C
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(pageSize).list(); ,/I.t DH
PaginationSupport ps = prF%.(G2)
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new PaginationSupport(items, totalCount, pageSize, `p-cSxR_
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startIndex); G`61~F%
return ps; :Yh+>c}N
} UKvW Jnz
}, true); }@+0/W?\.
} YnAm{YyI
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public List findAllByCriteria(final azp):*f("
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DetachedCriteria detachedCriteria){ 5c0 ZRV#
return(List) getHibernateTemplate \ :sUL!
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().execute(new HibernateCallback(){ *vxk@`K~
publicObject doInHibernate mxC;?s;~
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(Session session)throws HibernateException { v>)"HL"XG
Criteria criteria = *)T^ChD,
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detachedCriteria.getExecutableCriteria(session); ,m:.-iy?
return criteria.list(); & l&:`nsJ
} 3yF,ak{Sl
}, true); i%]EEVmN
} ,T$U'&;
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public int getCountByCriteria(final 'Aq{UGN
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DetachedCriteria detachedCriteria){ v%z=ysA
Integer count = (Integer) ]Ie 0S~
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getHibernateTemplate().execute(new HibernateCallback(){ [D4SW#
publicObject doInHibernate *C*U5~Zq7:
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(Session session)throws HibernateException { u cW-I;"
Criteria criteria = *fS"ym@
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detachedCriteria.getExecutableCriteria(session); 6Y?|w 3f
return Fj3a.'
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criteria.setProjection(Projections.rowCount xy[3u?,&s!
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()).uniqueResult(); !ons]^km
} MaQqs=
}, true); 9vc2VB$
return count.intValue(); 6}Ci>_i4#
} ag[wdoj
} H=vUYz
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用户在web层构造查询条件detachedCriteria,和可选的 ^%{7}g&$u
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 =K[yT:
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PaginationSupport的实例ps。 P{>!5|k
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ps.getItems()得到已分页好的结果集 O-hAFKx
ps.getIndexes()得到分页索引的数组 @:vwb\azVD
ps.getTotalCount()得到总结果数 `kXs;T6&
ps.getStartIndex()当前分页索引 %pL''R9VF
ps.getNextIndex()下一页索引 0znR0%~
ps.getPreviousIndex()上一页索引 -zeG1gr3
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 s*]}QmRpr
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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 <<5(0#y#
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一下代码重构了。 ^k">A:E2
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我把原本我的做法也提供出来供大家讨论吧: d^
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首先,为了实现分页查询,我封装了一个Page类: y?? XIsF
java代码: \X D6 pr@
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/*Created on 2005-4-14*/
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package org.flyware.util.page; PKiy5D*8p
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/** nmKp[-5
* @author Joa 9qzHS~l
* WW~sNC\3`(
*/ p}~JgEE
publicclass Page { 5Yq@;e
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/** imply if the page has previous page */ 4!no~ $b
privateboolean hasPrePage; }WXi$(@v
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/** imply if the page has next page */ @lr ztM
privateboolean hasNextPage; -x`@6
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/** the number of every page */ ;iL#7NG-R
privateint everyPage; X\qNG]
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/** the total page number */ Hf2_0wA3
privateint totalPage; RMu~l@
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/** the number of current page */ >_ T-u<E
privateint currentPage; s9DYi~/,
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/** the begin index of the records by the current tl^9WG
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query */ vV-`jsq20H
privateint beginIndex; w%jII{@,
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/** The default constructor */ 1K50Z.o&@
public Page(){ Y&Z.2