Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 yL%k5cO$N
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 :taRCh5
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 JrVBd hLr
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 !|;w(/
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分页支持类: n$YCIW)0
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java代码: G[[NDK
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package com.javaeye.common.util; 9KLhAYaq
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import java.util.List; J"O#w BM9
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publicclass PaginationSupport { m[!AOln)
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publicfinalstaticint PAGESIZE = 30; :fE*fU@
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privateint pageSize = PAGESIZE; "K*+8IO2
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privateList items; +gsk}>"
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privateint totalCount; S&m5]h!D
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privateint[] indexes = newint[0]; rXR}]|;>
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privateint startIndex = 0; q'p>__Ox
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public PaginationSupport(List items, int C},$(2>0+
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totalCount){ gZ1|b
setPageSize(PAGESIZE); 7f`x-iH!]7
setTotalCount(totalCount); )gAFz+
setItems(items); Q`X5W
setStartIndex(0); N~A#itmdx
} k<3_!?3
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public PaginationSupport(List items, int =G>.-Qfs
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totalCount, int startIndex){ "mtp0
setPageSize(PAGESIZE); (YrR8
setTotalCount(totalCount); ^IgS
setItems(items); :H\&2/j
setStartIndex(startIndex); :~33U)?{T
}
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public PaginationSupport(List items, int PCZ]R
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totalCount, int pageSize, int startIndex){ pL)xqKj
setPageSize(pageSize); @H+~2;B,
setTotalCount(totalCount); Ut_mrb+W
setItems(items); nsl*Dm"*F
setStartIndex(startIndex); 9A+M|;O
} 9GPb$gtx
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publicList getItems(){ :l`i4kx
return items; !qaDn.9
} {+\'bIV[
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publicvoid setItems(List items){ PGY9*0n
this.items = items; 8}z3CuM
} 4 l1 i>_R
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publicint getPageSize(){ gQR1$n0
return pageSize; 9FNwpL'C
} @>:i-5
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publicvoid setPageSize(int pageSize){ 5m`[MBt2g
this.pageSize = pageSize; ^W}MM8
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} J[r^T&o
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publicint getTotalCount(){ pns+y
return totalCount; B@-"1m~la?
} T`Ro)ORC#
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publicvoid setTotalCount(int totalCount){ ?[|hGR2L
if(totalCount > 0){ `#U ]iwW!
this.totalCount = totalCount; 4,zvFH*AH
int count = totalCount / }!=U^A)
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pageSize; C#$6O8O
if(totalCount % pageSize > 0) P\T| [%E'
count++; 5&*zY)UL
indexes = newint[count]; +;6)
for(int i = 0; i < count; i++){ <tW:LU(!
indexes = pageSize * t9Vb~ Ubdb
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} ] 9@X?q
}else{ EZ{/]gCK
this.totalCount = 0; Of#K:`1@
} esteFLm`6
} $l#{_~
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publicint[] getIndexes(){ Efvq?cG&
return indexes; CrO`=\
} ]hKgA~;
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publicvoid setIndexes(int[] indexes){ C d|W#.6
this.indexes = indexes; eQ\jZ0s;p
} 2/EK`S
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publicint getStartIndex(){ `I{ tZ$iD
return startIndex; [9HYO
} 117c,yM0
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publicvoid setStartIndex(int startIndex){ &D)2KD"N
if(totalCount <= 0) 0#
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this.startIndex = 0; J[6VBM.Y
elseif(startIndex >= totalCount) /ISLVp%H
this.startIndex = indexes Q ]0r:i=
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[indexes.length - 1]; )^";BVY
elseif(startIndex < 0) KqK9X
this.startIndex = 0; W\NG>t
else{ hbH#Co~o4#
this.startIndex = indexes ke^d8Z.
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[startIndex / pageSize]; h(|;\ ~
} Zd+>
} =+4 _j
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publicint getNextIndex(){ egWx9xX
int nextIndex = getStartIndex() + o"\{OX
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pageSize; ]'e AO
if(nextIndex >= totalCount) KD=bkZ&
return getStartIndex(); iU XM(]
else N|$5/bV
return nextIndex; 9 R
} EP(Eq
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publicint getPreviousIndex(){ ^6#-yDZC@
int previousIndex = getStartIndex() - I5Q~T5Ar
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pageSize; 1xIFvXru
if(previousIndex < 0) T$IUKR
return0; E$R_rX4x
else wcl!S {
return previousIndex; VW~Xbyf
} VRB~7\A5<)
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} ozuIwzi7N
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抽象业务类 T1bFxim#b
java代码: Op90NZI#K
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/** 0H<4+
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* Created on 2005-7-12 v?}pi
*/ rXuAixu!t
package com.javaeye.common.business; t%:G|n Sz
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import java.io.Serializable; *.xZfi_|
import java.util.List; Stt* 1gT
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import org.hibernate.Criteria; }`#Bf
import org.hibernate.HibernateException; t+J)dr
import org.hibernate.Session; YY\Rua/nG
import org.hibernate.criterion.DetachedCriteria; I0(8Z]x
import org.hibernate.criterion.Projections; a 1NCVZ
import zaBG=
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org.springframework.orm.hibernate3.HibernateCallback; $M-NR||k
import QY@nE
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org.springframework.orm.hibernate3.support.HibernateDaoS &62`Wr 0C
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upport; dhs#D:/{9
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import com.javaeye.common.util.PaginationSupport; {vjqy&?y
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public abstract class AbstractManager extends EL"4E',
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HibernateDaoSupport { !}y8S'Yjw
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privateboolean cacheQueries = false; rrYp'L
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privateString queryCacheRegion; }\U0[x#q
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publicvoid setCacheQueries(boolean pL%4= ]m
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cacheQueries){ |KTpK(6p
this.cacheQueries = cacheQueries; nwhm[AaNs
} D)h["z|F
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publicvoid setQueryCacheRegion(String 3/:LYvM<
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queryCacheRegion){ #.~.UHt
this.queryCacheRegion = /O+e#z2f<
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queryCacheRegion; b5[f 5
} HuK Aj
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publicvoid save(finalObject entity){ 9*f2b.Aj
getHibernateTemplate().save(entity); L,GShl 0S
} C CLfvex
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publicvoid persist(finalObject entity){ py}.00it
getHibernateTemplate().save(entity); 0@:Y>qVa
} O~nBz):2
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publicvoid update(finalObject entity){ \l>qY(gu
getHibernateTemplate().update(entity); G[y&`Qc)G
} ]<Z&=0i# 9
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publicvoid delete(finalObject entity){ t7sUtmq
getHibernateTemplate().delete(entity); DS.39NY
} :~-)Sm+^
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publicObject load(finalClass entity, dE+CIjW5
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finalSerializable id){ -,[~~
return getHibernateTemplate().load _!|=AIX
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(entity, id); h5<T.vV
} h 3eGq:!9
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publicObject get(finalClass entity, X
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finalSerializable id){ WNCM|VUl
return getHibernateTemplate().get ;G iI'M
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(entity, id); V+P8P7y37B
} {hlT`K
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publicList findAll(finalClass entity){ X}_QZO=z
return getHibernateTemplate().find("from 8}ii3P y
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" + entity.getName()); D!81(}p
} v$qpcu#o
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publicList findByNamedQuery(finalString Nck!z8
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namedQuery){ 6z1aG9G
return getHibernateTemplate #nxER
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().findByNamedQuery(namedQuery); L#83f]vG
} /h{go]&Nb
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publicList findByNamedQuery(finalString query, B:.;,@r]
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finalObject parameter){ MoC*tImWR
return getHibernateTemplate >u'/$k
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().findByNamedQuery(query, parameter); dqIZ#;:g
} D}=/w+
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publicList findByNamedQuery(finalString query, DQL06`pX/
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finalObject[] parameters){ Dx p>
return getHibernateTemplate }rFsU\]:q
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().findByNamedQuery(query, parameters); ?,A}E|jZ
} kKFuTem_3
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publicList find(finalString query){ 9q@z[+X
return getHibernateTemplate().find X}n&`y{/
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(query); _OyP>|L'
} hfl%r9o
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publicList find(finalString query, finalObject ;EE{~
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parameter){ jQH5$
return getHibernateTemplate().find [R@q]S/
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(query, parameter); ,qBnqi[
} jSUAU}u!M
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public PaginationSupport findPageByCriteria FJ3:}r6 "
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(final DetachedCriteria detachedCriteria){ 's56L,^:
return findPageByCriteria 1I:"0("}
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 4iL.4Uj{N
} 7cOg(6N
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public PaginationSupport findPageByCriteria Ba\wq:
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(final DetachedCriteria detachedCriteria, finalint C+Fh$
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startIndex){ cNuuzA
return findPageByCriteria '6dD^0dZ
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(detachedCriteria, PaginationSupport.PAGESIZE, softfjl&l
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startIndex); yNb#Ia
} utFcFdX
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public PaginationSupport findPageByCriteria iuH8g
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(final DetachedCriteria detachedCriteria, finalint 7 ~%
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pageSize, I;kUG_c(4
finalint startIndex){ P?3YHa^up
return(PaginationSupport) V5(tf'
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getHibernateTemplate().execute(new HibernateCallback(){ 7E\K!v_
publicObject doInHibernate jl 30\M7
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(Session session)throws HibernateException { ECE{xoc
Criteria criteria = w#gU1yu
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detachedCriteria.getExecutableCriteria(session); 8h@)9Q]d\
int totalCount = l/y
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((Integer) criteria.setProjection(Projections.rowCount 9$4/frd
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()).uniqueResult()).intValue(); hVt+%tmNy
criteria.setProjection .SKNIct
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(null); L(!!7B_,
List items = NdXy%Q
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criteria.setFirstResult(startIndex).setMaxResults c}I8!*\
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(pageSize).list(); 4Q`=t&u
PaginationSupport ps = V.P5v{
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new PaginationSupport(items, totalCount, pageSize, f@xfb
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startIndex); Y/eN)
return ps; )2<B$p
} ]%Q]C
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}, true); 71n uTE%!
} i"\AyKiJ
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public List findAllByCriteria(final |<+|Du1
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DetachedCriteria detachedCriteria){ @e?[oojrM
return(List) getHibernateTemplate Oa_o"p<Lr
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().execute(new HibernateCallback(){ /PB3^d>Q2
publicObject doInHibernate j
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(Session session)throws HibernateException {
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Criteria criteria = l)!woOt
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detachedCriteria.getExecutableCriteria(session); YK=#$,6
return criteria.list(); 65e
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} ;P0Y6v3
}, true); ?/|@ #&
} Zy+QA>d|
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public int getCountByCriteria(final fE7a]REK
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DetachedCriteria detachedCriteria){ HTtGpTsF
Integer count = (Integer) ptc H>wM!
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getHibernateTemplate().execute(new HibernateCallback(){ L8-[:1
publicObject doInHibernate :+dWJNY:
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(Session session)throws HibernateException { Mbi+Vv-
Criteria criteria = ~bWWu`h
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detachedCriteria.getExecutableCriteria(session); \qd)l
return DRg~HT
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criteria.setProjection(Projections.rowCount ,%b1 ]zZQ
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()).uniqueResult(); 3TvhOC>yG
} Sy0s`\[
}, true); [sO<6?LY
return count.intValue(); VL!kX``^F
} {msB+n~WZ
} "a`0w9Mm}
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用户在web层构造查询条件detachedCriteria,和可选的 2T2#HP
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 .=w`T
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PaginationSupport的实例ps。 JU2' ~chh
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ps.getItems()得到已分页好的结果集 JA(q>>4
ps.getIndexes()得到分页索引的数组 +?m=f}>W1
ps.getTotalCount()得到总结果数 w!h{P38
ps.getStartIndex()当前分页索引 \iLd6Qo_aq
ps.getNextIndex()下一页索引 `kT$Gx4x
ps.getPreviousIndex()上一页索引 9 0(oV&
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 n\)f.}YD8d
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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 Mn{Rg>X
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一下代码重构了。 zs^\zCb8
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我把原本我的做法也提供出来供大家讨论吧: /n}V7
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首先,为了实现分页查询,我封装了一个Page类: $gtT5{"PN(
java代码: KUn5S&eB
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/*Created on 2005-4-14*/ xMGd'l?
package org.flyware.util.page; l|QFNW[i
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/** W p*
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* @author Joa K<9MK>T
* 0`Qs=R`OM
*/ J3JRWy@?P
publicclass Page { iQj{J1V
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/** imply if the page has previous page */ j%<@uiu
privateboolean hasPrePage;
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/** imply if the page has next page */ rpI7W?hh
privateboolean hasNextPage; (I 0t*Se
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/** the number of every page */ _)H+..=
privateint everyPage; 1{glRY'
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/** the total page number */ !8M'ms>s=
privateint totalPage; 'WgwLE_
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/** the number of current page */ o)
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privateint currentPage; I:7,CV
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/** the begin index of the records by the current juZ3""
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query */ `d;izQ1_=
privateint beginIndex; ,Yt&PE
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