Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 57a2^
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 g"s$}5{8:
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 Migd(uw'
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 s>k Uh
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。 8$s9(n-_Y
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分页支持类: p.}Ls)I
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java代码: ^;,M}|<h
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package com.javaeye.common.util; 09A
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import java.util.List; dbwe?ksh
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publicclass PaginationSupport { gFeO}otm
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publicfinalstaticint PAGESIZE = 30; fV &KM*W*@
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privateint pageSize = PAGESIZE;
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privateList items; gQ o]
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privateint totalCount; %7"q"A r[
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privateint[] indexes = newint[0]; nG,A@/N
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privateint startIndex = 0; ^`*9QjY
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public PaginationSupport(List items, int
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totalCount){ O}+.U<V
setPageSize(PAGESIZE); e bm])~ZL
setTotalCount(totalCount); Uddr~2%(
setItems(items); p31NIf`
setStartIndex(0); >sfRI]OG
} whmdcVh.
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public PaginationSupport(List items, int 4~k\j
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totalCount, int startIndex){ 931bA&SL=/
setPageSize(PAGESIZE); aH 4c02s$
setTotalCount(totalCount); E[2m&3&
setItems(items); N^#ZJoR
setStartIndex(startIndex); V^7V[(~`
} bt"W(m&f
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public PaginationSupport(List items, int `e(c^ z#
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totalCount, int pageSize, int startIndex){ VeGL)
setPageSize(pageSize); aDq5C-MzG
setTotalCount(totalCount); :9O#ObFR
setItems(items); {E
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setStartIndex(startIndex); $h5xH9x
;
} M=%l}FSTw(
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publicList getItems(){ XF P atd
return items; UM!ENI|
} bHPYp5UwN
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publicvoid setItems(List items){ EqyeJq .
this.items = items; )`SES."
} !Nu<xq@!
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publicint getPageSize(){ {!.(7wV\
return pageSize; VO,!x~S!
} RS"H8P4W
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publicvoid setPageSize(int pageSize){ vGc,vjC3x
this.pageSize = pageSize; ;o^eC!:/%
} }E+!91't.^
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publicint getTotalCount(){ k'gh
return totalCount; m`IC6*
} U1@IX4^2`
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publicvoid setTotalCount(int totalCount){ [DJ flCR&
if(totalCount > 0){ c|lu&}BS
this.totalCount = totalCount; ?Y)vGlWDW<
int count = totalCount / tkVbo.[8K
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pageSize; $"`- ^
if(totalCount % pageSize > 0) 3!3xCO
count++; XUM!Qv
indexes = newint[count]; VcAue!MN
for(int i = 0; i < count; i++){ +J_c'ChN
indexes = pageSize * AK&S5F>D+B
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i; @En^wN
}
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}else{ M^MdRu
this.totalCount = 0; l*ayd>`~x
} `Y
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} X-
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publicint[] getIndexes(){ *n;!G8\
return indexes; AcS|c:3MUy
} O>qll6]{@
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publicvoid setIndexes(int[] indexes){ ZZWD8AX
this.indexes = indexes; cnSJ{T
} Dakoqke
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publicint getStartIndex(){ flk=>h|
return startIndex; rJPb 3F
} #?5 (o
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publicvoid setStartIndex(int startIndex){ IKABB W
if(totalCount <= 0) A&s:\3*Kh
this.startIndex = 0; B,M(@5wz
elseif(startIndex >= totalCount) UV5Ie!\nm
this.startIndex = indexes cYFiJJLG]
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[indexes.length - 1]; Acnl^x7Y1
elseif(startIndex < 0) e.]K L('
this.startIndex = 0; aF)1Nm[
else{ GRGzP&}@
this.startIndex = indexes ^sa#8^,K
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[startIndex / pageSize]; =3|O%\
} c05TsMF&O
}
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publicint getNextIndex(){ >^%7@i:@U
int nextIndex = getStartIndex() + 0%,!jW{`
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pageSize; n_$
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if(nextIndex >= totalCount) el2bd
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return getStartIndex(); dOqOw M.y
else A{UULVp
return nextIndex; y(Y!?X I
} 7+]=-
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publicint getPreviousIndex(){ D-8O+.@
int previousIndex = getStartIndex() - 0.dgoq3u
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pageSize; }~#pEX~j*
if(previousIndex < 0) VGtC)mG8)
return0; }tsYJlh5
else "[vu6 `m?
return previousIndex; }Mo=PWI1?
} @|<<H3I
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} ]GN7+8l
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抽象业务类 T;@;R%
java代码: ,$1eFgY%
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/** A6GE,FhsG
* Created on 2005-7-12 cU ?0(z7
*/ M(jgd
package com.javaeye.common.business; Wm_4avXtO
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import java.io.Serializable; i7ISX>%
import java.util.List; kjEEuEv
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import org.hibernate.Criteria; |_o=^?z'
import org.hibernate.HibernateException; .7i` (F)
import org.hibernate.Session; Uu!f,L;ty
import org.hibernate.criterion.DetachedCriteria; T6H}/#*tK
import org.hibernate.criterion.Projections; MxSM@3 v(
import wSb1"a
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org.springframework.orm.hibernate3.HibernateCallback; /V8}eZ97
import Q@
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org.springframework.orm.hibernate3.support.HibernateDaoS F_Y7@Ei/
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upport; H,+I2tEs
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import com.javaeye.common.util.PaginationSupport; Sl-v W
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public abstract class AbstractManager extends z74in8]
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HibernateDaoSupport { YGv<VOWG2
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privateboolean cacheQueries = false; , #U.j
@?=|Y
privateString queryCacheRegion; 1U^A56CN
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publicvoid setCacheQueries(boolean S|apw7C
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cacheQueries){ q6_u@:3u
this.cacheQueries = cacheQueries; 2R=DB`3
} bhkUKxd
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publicvoid setQueryCacheRegion(String IB#
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queryCacheRegion){ |;.o8}
this.queryCacheRegion = \"CZI<=TB
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queryCacheRegion; _@
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} wNQ*t-K
}b=}uiR#
publicvoid save(finalObject entity){ :T]o)
getHibernateTemplate().save(entity); xEf'Bmebk
} ]xX$<@HR
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publicvoid persist(finalObject entity){ 9Xl`pEhC
getHibernateTemplate().save(entity); y]J89
} #{k|I$
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publicvoid update(finalObject entity){ h3*Zfl<]
getHibernateTemplate().update(entity); 3pK*~VK
} L:_bg8eD#
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publicvoid delete(finalObject entity){ ogL EtqT
getHibernateTemplate().delete(entity); cU{e`<xjA
} 7<%<Ff@^)O
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publicObject load(finalClass entity, .C2TQ:B, .
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finalSerializable id){ h~(G$':^
return getHibernateTemplate().load krsYog(^z
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(entity, id); ;QW3CEaUq
} UlAzJO6"
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publicObject get(finalClass entity, ?;vgUO
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finalSerializable id){ " R-!(9k^`
return getHibernateTemplate().get io#&o;M<
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(entity, id); ,0E{h}(
} ZQ_xDKqRV
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publicList findAll(finalClass entity){ iC W*]U
return getHibernateTemplate().find("from d?:=PH
(9<guv
" + entity.getName()); Q$:{ W?eu!wL#p
return getHibernateTemplate } ~"hC3w
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().findByNamedQuery(query, parameter); ZTU&,1Y ;
} rAs,X
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publicList findByNamedQuery(finalString query, VxY+h`4#
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finalObject[] parameters){ =QK$0r]c'k
return getHibernateTemplate H|ER
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().findByNamedQuery(query, parameters); ^bc;[x&N
} c%[#~;E
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publicList find(finalString query){ ;zYqsS
return getHibernateTemplate().find a)S+8uU
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(query); $Bj;D=d@V
} -s|}Rh?Y
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publicList find(finalString query, finalObject -jn WZ5.
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parameter){ '0\@Mc U]
return getHibernateTemplate().find 'yV?*a
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(query, parameter); ^-rfvc
} sf]s",t~J
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public PaginationSupport findPageByCriteria CBDG./
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(final DetachedCriteria detachedCriteria){ rQEyD
return findPageByCriteria /;tPNp{!dw
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); K{ \;2M
} aB]m*~
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public PaginationSupport findPageByCriteria 7lS#f1E
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(final DetachedCriteria detachedCriteria, finalint {@<J_A
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startIndex){ V\})3i8
return findPageByCriteria "dROb}szn
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(detachedCriteria, PaginationSupport.PAGESIZE, QT9n,lX
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startIndex); =7m}yDs6$
} Q 2A7mGN
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public PaginationSupport findPageByCriteria N<QjdD&
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(final DetachedCriteria detachedCriteria, finalint ,o^y`l
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pageSize, M;0]u.D*=
finalint startIndex){ fZxIY,
return(PaginationSupport) U,+[5sbo
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getHibernateTemplate().execute(new HibernateCallback(){ RN)dS>$
publicObject doInHibernate 3SSm5{197
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(Session session)throws HibernateException { 6Z`R#d #I
Criteria criteria = Cn>ADWpT&
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detachedCriteria.getExecutableCriteria(session); <,AS8^$X[
int totalCount = _DrJVC~6@
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((Integer) criteria.setProjection(Projections.rowCount [HN|\afz
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()).uniqueResult()).intValue(); 0W3i()
criteria.setProjection >(y<0
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(null); `\X+ Ud|
List items = 7@6g<"I
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criteria.setFirstResult(startIndex).setMaxResults .i^7|o:
X*Z8CM_
(pageSize).list(); gr-fXZO
PaginationSupport ps = h?-#9<A
(;%|-{7e-
new PaginationSupport(items, totalCount, pageSize, nuo Pg3Nl
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startIndex); JT9N!CGZ
return ps; xAu/
} ,v&L:a
}, true); +kq'+ Y7
} i5>+}$1
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public List findAllByCriteria(final O$kq`'9
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DetachedCriteria detachedCriteria){ '+
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return(List) getHibernateTemplate [xh*"wT#g
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().execute(new HibernateCallback(){ $5L0.$Tj
publicObject doInHibernate ,*]d~Y
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(Session session)throws HibernateException { sz--27es
Criteria criteria = __[xD\ES
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detachedCriteria.getExecutableCriteria(session); ^1Xt]T`e
return criteria.list(); }n7th
} bu&t'?zx!
}, true); px SX#S6I
} `z0{S!
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public int getCountByCriteria(final ,Rx{yf]k
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DetachedCriteria detachedCriteria){ .bVmqR`
Integer count = (Integer) IScRsxFb
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getHibernateTemplate().execute(new HibernateCallback(){ -o+74=E8[?
publicObject doInHibernate =pA
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(Session session)throws HibernateException { 'a^{=+
Criteria criteria = |0{u->+ )
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detachedCriteria.getExecutableCriteria(session); q>s-Y|
return [+w3J#K
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criteria.setProjection(Projections.rowCount GHF_R,7
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()).uniqueResult(); ?R-9W+U%f
} YpUp@/"
}, true); Omi^>c4G
return count.intValue(); ?EU\}N J
} N~pIC2Woo
} r}u%#G+K,
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用户在web层构造查询条件detachedCriteria,和可选的 CK_(b"
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 5cK@WE:
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PaginationSupport的实例ps。 >QHo@Zqj(
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ps.getItems()得到已分页好的结果集 XT,#g-oi
ps.getIndexes()得到分页索引的数组 7ou46v|m5
ps.getTotalCount()得到总结果数 p.fF}B
ps.getStartIndex()当前分页索引 ED$DSz)x
ps.getNextIndex()下一页索引 BIf^~jAER%
ps.getPreviousIndex()上一页索引 ?zq+jLyo
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 o2-@o= F
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 b'ml=a#i0
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一下代码重构了。 {dPgf
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我把原本我的做法也提供出来供大家讨论吧: oUx[+Gnv
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首先,为了实现分页查询,我封装了一个Page类: %Y4e9T".
java代码: ">dq0gD
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/*Created on 2005-4-14*/ ^TXf sQs
package org.flyware.util.page; Swtbl`,
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/** \g-j9|0
* @author Joa ,`td@Y
* #>@z
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*/ v_PdOp[
k
publicclass Page { lf>nbvp
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/** imply if the page has previous page */ YEYY}/YX
privateboolean hasPrePage; Qq0l*)mX
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/** imply if the page has next page */ *i$ePVU
privateboolean hasNextPage; %-;bu|
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/** the number of every page */ #
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privateint everyPage; AyE\fY5
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/** the total page number */ Y9 r3XhVI
privateint totalPage; vxN0,l
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/** the number of current page */ q]4pEip
privateint currentPage; h`MdKX$
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/** the begin index of the records by the current 7z~Ghz
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query */ OIaYHA
privateint beginIndex; ,<ya@Fi{
h.
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/** The default constructor */ s[3fqdLP&
public Page(){ ,[48Mspp
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} %4>x!{jwV
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/** construct the page by everyPage 83]PA<R
* @param everyPage 'bW5Fr>W
* */ ]]iO- }
public Page(int everyPage){ +1{fzb>9_
this.everyPage = everyPage; Ar,
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} 0x)dnq\
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/** The whole constructor */ O ++/ry%k
public Page(boolean hasPrePage, boolean hasNextPage, N=,j}FY
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int everyPage, int totalPage, PE@+w#i7*
int currentPage, int beginIndex){ 7h<> k*E)
this.hasPrePage = hasPrePage; fu\s`W6f&
this.hasNextPage = hasNextPage; b#Kq[}
this.everyPage = everyPage; (wt+`_6
this.totalPage = totalPage; k{Lv37H
this.currentPage = currentPage; %l9$a`&
this.beginIndex = beginIndex;
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} mv
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/** 8<PKKDgbfd
* @return mVH,HqsXa
* Returns the beginIndex. H:oQ
*/ SX+RBVZU
publicint getBeginIndex(){ #n})X,ip2
return beginIndex; 66ohmP@04Z
} ^7XAw:
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/** ;[5r7
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* @param beginIndex #1Z7R/
* The beginIndex to set. -l*A
*/
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publicvoid setBeginIndex(int beginIndex){ yqcM(,0]
this.beginIndex = beginIndex; tEhr
} y$oW!
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/** aw$Y`6,S
* @return xks?y.wA
* Returns the currentPage. zNtq"T [
*/ Lx+`<<_dJ
publicint getCurrentPage(){ g6' !v
return currentPage; IcoowZZ
} 70iH0j)
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/** TgaYt\"i[
* @param currentPage <f%/px%1
* The currentPage to set. 9Q[>.):
*/ >[3X]n,0
publicvoid setCurrentPage(int currentPage){ uW[3G
this.currentPage = currentPage; dtW0\^ .L
} #EwK"S~
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/** G=$}5; t
* @return 3V-6)V{KaE
* Returns the everyPage. c f*zejbw
*/ 9) ea.Gu
publicint getEveryPage(){ zl)&U=4l
return everyPage; YN#XmX%
} :WX0,-Gn
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/** +i)AS0?d
* @param everyPage $%He$t
* The everyPage to set. YBylyVZ
*/ @36S}5Oa
publicvoid setEveryPage(int everyPage){ zh?4K*>.k
this.everyPage = everyPage; v ($L
} BI/y<6#rR
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/** +qE']yzm!
* @return 8ui=2k(
* Returns the hasNextPage. TG]}X\c+V|
*/ nEVbfNo0
publicboolean getHasNextPage(){ JD&U}dJ
return hasNextPage; #:
hVF/
} )0|):g
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/** Wm>b3:
* @param hasNextPage qy9i9$8
* The hasNextPage to set. x7gjG"V
*/ ak2dn]]D
publicvoid setHasNextPage(boolean hasNextPage){ d
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this.hasNextPage = hasNextPage; uGCtLA+sL
} ]L(54q;W
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/** +S0u=u65
* @return ,>w}xWSYpG
* Returns the hasPrePage. pzSqbgfrQ
*/ + (=I8s/
publicboolean getHasPrePage(){ 1*c>I@I;
return hasPrePage; |Mlh;
} DPeVKyjU
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