Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 /WM
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Tp9LBF
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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$j`+`
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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 (V
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分页支持类: s_RYYaM
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java代码: 7}nOF{RH]
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package com.javaeye.common.util; )of_"gZ$3A
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import java.util.List; b?r0n]
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publicclass PaginationSupport { /a]+xL
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publicfinalstaticint PAGESIZE = 30; I{M2nQi
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privateint pageSize = PAGESIZE; Ue8_Q8q5
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privateList items; YrB-;R1+
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privateint totalCount; ZkqC1u3
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privateint[] indexes = newint[0]; 0wOgQ n
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privateint startIndex = 0; hR. EZ|.
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public PaginationSupport(List items, int JhuKW>7
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totalCount){ E6n;_{Se/S
setPageSize(PAGESIZE); <@Ew-JU
setTotalCount(totalCount); }}ogdq
setItems(items); *aTM3k)Zs
setStartIndex(0); >+8mq]8^
} Q>X ;7nt0
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public PaginationSupport(List items, int (spX3n%p
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totalCount, int startIndex){ ;&[0 h)
setPageSize(PAGESIZE); gg6&Fzp
setTotalCount(totalCount); vnIxI a
setItems(items); J :,
setStartIndex(startIndex); "i#!
} <nIU]}q
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public PaginationSupport(List items, int \f._I+gJ
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totalCount, int pageSize, int startIndex){ 1AhL-Lj
setPageSize(pageSize); EQ7cK63
setTotalCount(totalCount); OD*DHC2rN]
setItems(items); W}(dhgf
setStartIndex(startIndex); dedi6Brl
} K_RrSI&>
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publicList getItems(){ 76c}Rk^
return items; S~m*t i(
} }P^n /
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publicvoid setItems(List items){ @89mj{
this.items = items; &\1Dy}:
} ay4|N!ExO
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publicint getPageSize(){ QAX+oy
return pageSize; 1)k))w 9
} G|H\(3hHLZ
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publicvoid setPageSize(int pageSize){ _)^(-}(_D
this.pageSize = pageSize; 6W3}6p
} 2Q<_l*kk(
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publicint getTotalCount(){ />]/At
return totalCount; }~\J7R'
} S$V'_
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publicvoid setTotalCount(int totalCount){ js2?t~E]
if(totalCount > 0){ aIkxN&
this.totalCount = totalCount; p%j@2U
int count = totalCount / _gU[FUBtJ
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pageSize; bZa?h.IF
if(totalCount % pageSize > 0) }_u)3X.O
count++; R|tjvp-[}
indexes = newint[count]; ;m;wSp
for(int i = 0; i < count; i++){ 'd/A+W
indexes = pageSize * r Cmqq/hZ
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} <$ '#@jW
}else{ b}[{'
this.totalCount = 0; [D/q%
} 3`-[95w
} |n]^gTJt
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publicint[] getIndexes(){ tXfB.[U
return indexes; Qza[~6
} 8B\,*JGY2
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publicvoid setIndexes(int[] indexes){ qB"y'UW8
this.indexes = indexes; i"_JF-IbN
} ] _#[oS
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publicint getStartIndex(){ EEF}Wf$f
return startIndex; W*VQ"CW{^]
} UlQ }
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publicvoid setStartIndex(int startIndex){ 8vnU!r
if(totalCount <= 0) g[!sGa&
this.startIndex = 0; '?Hy"5gUA
elseif(startIndex >= totalCount) K@W~
this.startIndex = indexes IgSe%B
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[indexes.length - 1]; mVk:[
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elseif(startIndex < 0) JCE364$$"
this.startIndex = 0; nj)M$'
else{ k98--kc5
this.startIndex = indexes \#~~,k
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[startIndex / pageSize]; !L> 'g
} BXLhi(.s
} |n Mbf
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publicint getNextIndex(){ RkC?(p
int nextIndex = getStartIndex() + .bew,92
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pageSize; [NC^v.[1[
if(nextIndex >= totalCount) 5E~][. d
return getStartIndex(); wxvt:==
else 0(0Ep(Vj
return nextIndex; bQ_i&t\yzB
} ~H?RHYP~
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publicint getPreviousIndex(){ Bg;bBA!L
int previousIndex = getStartIndex() - b>;5#OQfn
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pageSize; Z<xSU?J
if(previousIndex < 0) NOo&5@z;H
return0; TlAY=JwW
else m;8_A|$A
return previousIndex; cLJ|VD7
} ;`@DQvVZ:
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抽象业务类 -%"MAIJnX
java代码: |+ @
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/** Sd}fse
* Created on 2005-7-12 qo4AQ}0 <
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package com.javaeye.common.business; o"TEmZUP
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import java.io.Serializable; IjD:
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import java.util.List; H=7dp%b"
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import org.hibernate.Criteria; rcNM,!dZ
import org.hibernate.HibernateException; ^ !E;+o' t
import org.hibernate.Session; aRj3TtFh
import org.hibernate.criterion.DetachedCriteria; r=8]Ub[
import org.hibernate.criterion.Projections; rJD>]3D 5p
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org.springframework.orm.hibernate3.HibernateCallback; u=k\]W-
import G;wv.|\
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org.springframework.orm.hibernate3.support.HibernateDaoS 9sJbz=o]r
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upport; m6aoh^I
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import com.javaeye.common.util.PaginationSupport; Po9 3&qE
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public abstract class AbstractManager extends o]PSyVg
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HibernateDaoSupport { A~O
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privateboolean cacheQueries = false; $kkdB,y
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privateString queryCacheRegion; wf<uG|90
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publicvoid setCacheQueries(boolean Iu%/~FgPj{
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cacheQueries){ 4hZ-^AL"(
this.cacheQueries = cacheQueries; :IbrV@gN{@
} tE<L4;t
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publicvoid setQueryCacheRegion(String ^J\)cw
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queryCacheRegion){ V ;"?='vVe
this.queryCacheRegion = <P$b$fh/
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queryCacheRegion; irgjq/&d
} Z/:(*F C
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publicvoid save(finalObject entity){ )bPwB.} kq
getHibernateTemplate().save(entity); 9]7+fu
} DEqk9Exk`
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publicvoid persist(finalObject entity){ (Q#ArMMORI
getHibernateTemplate().save(entity); vWjK[5
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} bbA+ZLZJn
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publicvoid update(finalObject entity){ a5]~%xdK
getHibernateTemplate().update(entity); *E+)mB"~
} CDoZv""
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publicvoid delete(finalObject entity){ plb'EP>e
getHibernateTemplate().delete(entity); 6L'cD1pu
} :8yrtbf$
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publicObject load(finalClass entity, ,&z_ 2m
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finalSerializable id){ q2&&n6PYW
return getHibernateTemplate().load ~'v^__8
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(entity, id); ' G)Wy|*
} e>sr)M
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publicObject get(finalClass entity, e[>(L% QV+
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finalSerializable id){ 3l5q?" $
return getHibernateTemplate().get
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(entity, id); _S@s
} cg0L(oI~
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publicList findAll(finalClass entity){ nb(#;3DQ
return getHibernateTemplate().find("from ]
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" + entity.getName()); pr@8PD2%
} *N< 22w
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publicList findByNamedQuery(finalString }*IX34
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namedQuery){ )x?F1/
return getHibernateTemplate >:KPvq!0
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().findByNamedQuery(namedQuery); } [D[ZLv
} NVJvCs)3f
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publicList findByNamedQuery(finalString query, _pjpPSV6J
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finalObject parameter){ cg$7`/U
return getHibernateTemplate #H M0s~^w&
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().findByNamedQuery(query, parameter); RrKs!2sCT
} u+XZdV
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publicList findByNamedQuery(finalString query, JcvK]x
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finalObject[] parameters){ J=zh+oLCV
return getHibernateTemplate e?RHf_d3T-
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().findByNamedQuery(query, parameters); b3y@!_'c
} ]*I&104{
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publicList find(finalString query){ CNfeHMT
return getHibernateTemplate().find Jq/([
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(query); vTP'\^;
} /$+ifiFT
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publicList find(finalString query, finalObject A%%WPBk{O
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parameter){ oNl_r: G
return getHibernateTemplate().find $;$_N43
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(query, parameter); qo$<&'r
} nyTfTn
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public PaginationSupport findPageByCriteria 1w1(FpQO.
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(final DetachedCriteria detachedCriteria){ [A[vR7&S
return findPageByCriteria nJA\P1@m
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); z`f1|Ok
} txTDuS
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public PaginationSupport findPageByCriteria /38^N|/Zr
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(final DetachedCriteria detachedCriteria, finalint `4(k ?Pk2
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startIndex){ 0'VwObq
return findPageByCriteria fu\M2"e
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(detachedCriteria, PaginationSupport.PAGESIZE, L[##w?Xf.
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startIndex); +r4^oT[-
} GZ*cV3Y`&
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public PaginationSupport findPageByCriteria F9-xp7T
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(final DetachedCriteria detachedCriteria, finalint f>l}y->-Ug
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pageSize, k((_~<$2K
finalint startIndex){ v:s~Y
return(PaginationSupport) [ V/*{Z
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getHibernateTemplate().execute(new HibernateCallback(){ hZc$`V=R
publicObject doInHibernate xNE<$Bz
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(Session session)throws HibernateException { R9fM9
Criteria criteria = /R 2:Js
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detachedCriteria.getExecutableCriteria(session); vKol@7%N
int totalCount = ^MQ7*g6o
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((Integer) criteria.setProjection(Projections.rowCount a:v&pj+|<
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()).uniqueResult()).intValue(); Fag%#jxI
criteria.setProjection /_aFQ>.4n
{ p1#H`
(null); ^e^M
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List items = 8]'qJ;E2
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criteria.setFirstResult(startIndex).setMaxResults h]vA%VuE'E
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(pageSize).list(); V 7%rKK
PaginationSupport ps = w*\)]bTs
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new PaginationSupport(items, totalCount, pageSize, /nGsl<
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startIndex); 9q;+ Al^Z
return ps; ^hRos
} lUUeM\
}, true); >/ W:*^g)
} 0rjxWPc
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public List findAllByCriteria(final JX`+b
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DetachedCriteria detachedCriteria){ ![{> f6{J
return(List) getHibernateTemplate W@JmG`Sy
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().execute(new HibernateCallback(){ r;I3N+
publicObject doInHibernate QJ-6aB
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(Session session)throws HibernateException { IbF[nQ
Criteria criteria = Mm+_>
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detachedCriteria.getExecutableCriteria(session); |SQ5 Sb
return criteria.list(); Et4gRS)\
} .E"hsGH9h
}, true); shjS^CP
} 28>gAz.#
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public int getCountByCriteria(final Mw*R~OX
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DetachedCriteria detachedCriteria){ bAGQ
Integer count = (Integer) 7M=`Z{=9
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getHibernateTemplate().execute(new HibernateCallback(){ 9JJ(KY
publicObject doInHibernate ]fnc.^{
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(Session session)throws HibernateException { s+h`,gg9
Criteria criteria = BC9rsb
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detachedCriteria.getExecutableCriteria(session); _U|s!60'
return |Q?IV5%$
pg [F{T<
criteria.setProjection(Projections.rowCount I+kDx=T!
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()).uniqueResult(); BD\xUjd?)Q
} Wg3y
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}, true); `Q' 0l},
return count.intValue(); 0ua.aL'
} ggzg,~V
} hwSn?bkw
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用户在web层构造查询条件detachedCriteria,和可选的 ^} %OqP
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 :{E;*v_!v
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PaginationSupport的实例ps。 `p|{(g'
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ps.getItems()得到已分页好的结果集 R0B\| O0Uv
ps.getIndexes()得到分页索引的数组 2E9Cp
ps.getTotalCount()得到总结果数 WSz#g2a
ps.getStartIndex()当前分页索引 xrFFmQ<_W
ps.getNextIndex()下一页索引 )}0(7z
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ps.getPreviousIndex()上一页索引 ]bz']`
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Gg]>S#^3
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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 Fo|6 PoSo
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一下代码重构了。 6}qp;mR
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我把原本我的做法也提供出来供大家讨论吧: Eaf6rjD
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首先,为了实现分页查询,我封装了一个Page类: &^=6W3RD
java代码: Rq-BsMX!A
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/*Created on 2005-4-14*/ Q=}p
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package org.flyware.util.page; 5
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/** u0(H!
* @author Joa Ikv@}^p 7
* Uo>pV9xRG
*/ 80TSE*
publicclass Page { .bE+dA6:v
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/** imply if the page has previous page */ A>8"8=C
privateboolean hasPrePage; vq-Tq>
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