Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Pp!W$C:
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Q5JeL6t
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 d?.x./1[qi
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 4F?1,-X
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分页支持类: 3WS %H17
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java代码: _u;
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package com.javaeye.common.util; \=~Ap#Mpc4
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import java.util.List; %e(,PL
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publicclass PaginationSupport { gK'MUZ()
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publicfinalstaticint PAGESIZE = 30; 3}Pa,uN
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privateint pageSize = PAGESIZE; r{_'2Z_i
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privateList items; `shB[Lt
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privateint totalCount; * ?K=;$
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privateint[] indexes = newint[0]; I$&/?ns@O
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privateint startIndex = 0; Yu=^`I
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public PaginationSupport(List items, int <4Fd~
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totalCount){ EMo6$(
setPageSize(PAGESIZE); "M
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setTotalCount(totalCount); JcP'+@X"
setItems(items); E:ytdaiT
setStartIndex(0); 7blZAA?-
} ='FEC-f95
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public PaginationSupport(List items, int Cnolka"
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totalCount, int startIndex){ V-31x )
setPageSize(PAGESIZE); <|4j<U
setTotalCount(totalCount); {BF\G%v;+
setItems(items); S.z ;Bm
setStartIndex(startIndex); 7)T+!>
} b#M<b.R)
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public PaginationSupport(List items, int \r2w@F{C
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totalCount, int pageSize, int startIndex){ DuWP)#kg
setPageSize(pageSize); ~gf$ L9
setTotalCount(totalCount); LLE~V~j
setItems(items); e0TnA
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setStartIndex(startIndex); 2a^(8A`7W
} qz:OnQv!
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publicList getItems(){ [qz6_WOo
return items; aj\'qRrU$
} `C1LR,J
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publicvoid setItems(List items){ ?OSd8E+itM
this.items = items; ]1K
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} }fA3{Ro
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publicint getPageSize(){ Z#Fw 1
return pageSize; /c7j@=0
} YW5E
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publicvoid setPageSize(int pageSize){
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this.pageSize = pageSize; ru&RL
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} !"kvXxp^
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publicint getTotalCount(){ 75F&s,4+
return totalCount; 3"".kf,O5e
} HOw hl
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publicvoid setTotalCount(int totalCount){ Rm
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if(totalCount > 0){ ;ry{cq
this.totalCount = totalCount; l*eA
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int count = totalCount / Zj JD@,j
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pageSize; ^ey\ c1K
if(totalCount % pageSize > 0) WM#!X!Vo
count++; \8pbPo=x
indexes = newint[count]; sOJ~PRA
for(int i = 0; i < count; i++){ t!k 0n&P
indexes = pageSize * 9we=aX5
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} <[q)2 5RL
}else{ A-~)7-
this.totalCount = 0; gp}S 1
} k4@GjO1"$
} (X8N?tJ
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publicint[] getIndexes(){ }N[sydL
return indexes; )*uI/E
} bIH2cJ
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publicvoid setIndexes(int[] indexes){ ~UnfS};U
this.indexes = indexes; 6B 8!2
} vw3W:TL
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publicint getStartIndex(){ >[p+L='
return startIndex; *-n$n
} <Z5prunov
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publicvoid setStartIndex(int startIndex){ w 8E,zH
if(totalCount <= 0) 9> |rIw
this.startIndex = 0; HG^8&uh]
elseif(startIndex >= totalCount) hk=+t&Y<H
this.startIndex = indexes /v8qT'$^
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[indexes.length - 1]; ~5|a9HV:
elseif(startIndex < 0) @.5Ybgn
this.startIndex = 0; C/E3NL8
else{ H1w;Wb1se
this.startIndex = indexes +V) (,f1
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[startIndex / pageSize]; y0Tb/&xN
} LC}]6
} (]pQ.3
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publicint getNextIndex(){ |k)u..k{>
int nextIndex = getStartIndex() + CkP!4^J qQ
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pageSize; "}!vYr
if(nextIndex >= totalCount) ?gkK*\x2
return getStartIndex(); -,rl[1ZYZ
else BYGLYT;Z
return nextIndex; X0lIeGwrQ
} WgjaMmht
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publicint getPreviousIndex(){ FrVD~;
int previousIndex = getStartIndex() - d<whb2l
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pageSize; J@$>d
if(previousIndex < 0) {S}/LSNB
return0; F[+sc Mx!G
else )TWf/Lcp
return previousIndex; c>^_4QQ
} c{E-4PYbah
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} T^79p$
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抽象业务类 {C3bCVQ]o
java代码: Lt*H|9
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/** )S`A+M K]
* Created on 2005-7-12 M_PL{
*/ d BJM?/
package com.javaeye.common.business; b w cPY
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import java.io.Serializable; 9|go`^*.
import java.util.List; /E*P0y~KTW
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import org.hibernate.Criteria; s^AYPmR6
import org.hibernate.HibernateException; ,7'l$-r l
import org.hibernate.Session; xNx!2MrR;
import org.hibernate.criterion.DetachedCriteria; *BF1Sso
import org.hibernate.criterion.Projections; 2^juLXc|R
import zgO?%O
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org.springframework.orm.hibernate3.HibernateCallback; \'p)kDf
import Wl*\kQ}U
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org.springframework.orm.hibernate3.support.HibernateDaoS ^RY_j>i
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upport; jW6@U%[!b
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import com.javaeye.common.util.PaginationSupport; h rZ\ O?j
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public abstract class AbstractManager extends *z(.D\{%
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HibernateDaoSupport { Obw uyhjQ
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privateboolean cacheQueries = false; I*0W\Qz@
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privateString queryCacheRegion; ;DRJL
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publicvoid setCacheQueries(boolean ?1[go+56X
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cacheQueries){ Z,!Rj7wZ
this.cacheQueries = cacheQueries; 7`P(LQAr!
} &)wQ|{P~k
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publicvoid setQueryCacheRegion(String QN0Ik 2L
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queryCacheRegion){ +tuC845
this.queryCacheRegion = l jNd!RaB
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queryCacheRegion; D7=gUm>
} 94n,13
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publicvoid save(finalObject entity){ ~#gVs*K
getHibernateTemplate().save(entity); r<"1$K~Ka
} DB?[h<^m
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publicvoid persist(finalObject entity){ k6dSj>F>
getHibernateTemplate().save(entity); }+u<^7$g|
} j|
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publicvoid update(finalObject entity){ DTJ~.
getHibernateTemplate().update(entity); wD*_S}]
} =!p6}5Z
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publicvoid delete(finalObject entity){ Ble <n6
getHibernateTemplate().delete(entity); h883pe=
} Qx
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publicObject load(finalClass entity, yy%J{;
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finalSerializable id){ 7^:s/xHO*
return getHibernateTemplate().load or(Z-8a_
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(entity, id); (}}BZS&.
} F n6>n04v
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publicObject get(finalClass entity, 6W~F
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finalSerializable id){ aLP2p]
return getHibernateTemplate().get }bHdU]$}
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(entity, id); ;zs4>>^>
} u dH7Q&"
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publicList findAll(finalClass entity){ +]B^*99
return getHibernateTemplate().find("from TlM ]d;9G
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" + entity.getName()); dGZVWEaPfx
} 'os-+m@
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publicList findByNamedQuery(finalString &L+u]&!6C
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namedQuery){ ]2tX'=X
return getHibernateTemplate .vwOp*3\
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().findByNamedQuery(namedQuery); U+nwLxe'
} .(3B}}gB>
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publicList findByNamedQuery(finalString query, (3 B;
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finalObject parameter){ sgFpZk
return getHibernateTemplate E@t^IGDr
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().findByNamedQuery(query, parameter); MB:E/
} M]eH
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publicList findByNamedQuery(finalString query, skr^m%W
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finalObject[] parameters){ Pgb<;c:4
return getHibernateTemplate 1P&c:n
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().findByNamedQuery(query, parameters); WCU[]A
} Wrt3p-N"D
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publicList find(finalString query){ w0VJt<e*
return getHibernateTemplate().find Gv3a<Knn4
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(query); ~M+|g4W%
} ]w! x
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publicList find(finalString query, finalObject fokOjTE
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parameter){ QD q2<
return getHibernateTemplate().find |fq1Mn8
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(query, parameter); F5:4 B]ZF
} iC$~v#2
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public PaginationSupport findPageByCriteria j[9xF<I
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(final DetachedCriteria detachedCriteria){ iiKFV>;t/
return findPageByCriteria (lT
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); \2pJ ]
} USJ4qv+-
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public PaginationSupport findPageByCriteria ,~%Qu~\
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(final DetachedCriteria detachedCriteria, finalint <HI5xB_
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startIndex){ 6D@tCmmq
return findPageByCriteria 'd(OFE-hn
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(detachedCriteria, PaginationSupport.PAGESIZE, cBiv=!n
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startIndex); R2Lq,(@-
} 9kWyO:a_(
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public PaginationSupport findPageByCriteria pNCk~OM
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(final DetachedCriteria detachedCriteria, finalint ey@y?X=
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pageSize, XLI'f$w&
finalint startIndex){ i%D/@$\D6
return(PaginationSupport) vUY?Eb[
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getHibernateTemplate().execute(new HibernateCallback(){ )k- 7mwkZ
publicObject doInHibernate VNx}ADXu ]
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(Session session)throws HibernateException { a:7"F{D91
Criteria criteria = ,`B*rCOa
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detachedCriteria.getExecutableCriteria(session); 0A/GWSmF
int totalCount = }Sqey:9jH
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((Integer) criteria.setProjection(Projections.rowCount n +`( R]Q
's(0>i
()).uniqueResult()).intValue(); >5i1M^g(
criteria.setProjection m%'9z L c
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(null); g=:%j5?.e
List items = jrvhTej
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criteria.setFirstResult(startIndex).setMaxResults 9Or3X/:o
!s9<%bp3
(pageSize).list(); `9kjYSd#E
PaginationSupport ps = J<V}g v
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new PaginationSupport(items, totalCount, pageSize, w[n|Sauy,
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startIndex); 6WzE'0Nyr
return ps; rbqH9 S
} 8~Rja
}, true);
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} 3-FS} {,
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public List findAllByCriteria(final qd%5[A
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DetachedCriteria detachedCriteria){ #B&D
return(List) getHibernateTemplate 72@8M
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().execute(new HibernateCallback(){ gPd:>$
publicObject doInHibernate jgVra*
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(Session session)throws HibernateException { plv"/K JM
Criteria criteria = `[C8iF*Y"
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detachedCriteria.getExecutableCriteria(session); cs8bRXjHa
return criteria.list(); 7E%ehM6Y
} GKZn|<Y|{c
}, true); hUxpz:U*
} cSnm \f
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public int getCountByCriteria(final =uYSZR
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DetachedCriteria detachedCriteria){ 9c}LG5
Integer count = (Integer) @|j`I1r.A
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getHibernateTemplate().execute(new HibernateCallback(){ #z6RzZu
publicObject doInHibernate nv2Y6e}dG
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(Session session)throws HibernateException { wGBQ.Ve[
Criteria criteria = '.#KkvE##
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detachedCriteria.getExecutableCriteria(session); }^pnwo9vV
return _(0!bUs>
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criteria.setProjection(Projections.rowCount w-HgC
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()).uniqueResult(); pW:U|m1dS
} KJ.ra\F
}, true); }V ;PaX
return count.intValue(); +`yDW N?7
} "k"q)5c
} _g0
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用户在web层构造查询条件detachedCriteria,和可选的 <Lyz7R6
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 _ _-rP
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PaginationSupport的实例ps。 R
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ps.getItems()得到已分页好的结果集 LZX-am`%
ps.getIndexes()得到分页索引的数组 o//N"S.)
ps.getTotalCount()得到总结果数 kVe^g]F
ps.getStartIndex()当前分页索引 s><RL]+{G+
ps.getNextIndex()下一页索引 H_o<!YxK
ps.getPreviousIndex()上一页索引
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 4Qz
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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 7`~h'(k
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一下代码重构了。 ;k (}~_
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我把原本我的做法也提供出来供大家讨论吧: $B2*
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首先,为了实现分页查询,我封装了一个Page类: shYcfLJ
java代码: N{q5E,}
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/*Created on 2005-4-14*/ RRV@nDf
package org.flyware.util.page; rfXM*h
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/** \%mR*J+
* @author Joa RgRyo
* e@L+z
*/ n`vqCO7@'
publicclass Page { e&<#8;2X
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/** imply if the page has previous page */ YV.*8'*
privateboolean hasPrePage; WxWgY}`
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/** imply if the page has next page */ FK
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privateboolean hasNextPage; U%t:]6d&}
0 m";=:(w
/** the number of every page */ j<"0ym)A
privateint everyPage; (J\D"4q
v~L} :
/** the total page number */ 8{4I6;e-
privateint totalPage; qWw@6VvoQ
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/** the number of current page */ 6Ck?O/^
privateint currentPage; t=xO12Z
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/** the begin index of the records by the current G?<L{J2"Q
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query */ t{F6+d p
privateint beginIndex; L6r&