Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 d_f*'M2Gv
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 cVarvueS
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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 Eh|6{LDn!
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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\Y,4&bI
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分页支持类: k8SY=HP
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java代码: YACx9K H
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package com.javaeye.common.util; BPKrRex
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import java.util.List; D5xTuv9T
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publicclass PaginationSupport { %U.x9UL
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publicfinalstaticint PAGESIZE = 30; P1]F0fR
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privateint pageSize = PAGESIZE; a3z_o)"
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privateList items; cg_tJ^vrY
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privateint totalCount; ;NAKU
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privateint[] indexes = newint[0]; P]2 /}\f
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privateint startIndex = 0; (y\.uPu!
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public PaginationSupport(List items, int a^X% (@Sg
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totalCount){ 7s{['t
setPageSize(PAGESIZE); }s#4m
setTotalCount(totalCount); _W,?_"[R=
setItems(items); rJtk4hOF
setStartIndex(0); P.=Dd"La
} F4~O-g.<
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public PaginationSupport(List items, int %x}Unk
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totalCount, int startIndex){ 8u"C7} N_
setPageSize(PAGESIZE); x
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setTotalCount(totalCount); JuRWR0@`
setItems(items); (tT%rj!
setStartIndex(startIndex); w*(1qUF#%
} ,wHlU-%
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public PaginationSupport(List items, int bIk4?S
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totalCount, int pageSize, int startIndex){ mM+^v[=
setPageSize(pageSize); .\)ek[?
setTotalCount(totalCount); NID2$ p
setItems(items); BHNJH
setStartIndex(startIndex); {n<1uh9~$8
} UD5hk
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publicList getItems(){ *Ct
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return items; P`_Q-vu
} a+9_sUq
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publicvoid setItems(List items){ wLg@BSC.
this.items = items; Y]B9*^d<
} uhwCC
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publicint getPageSize(){ [?]p I
return pageSize; bQu@.'O!k
} bZ+Hu~
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publicvoid setPageSize(int pageSize){ N~(?g7
this.pageSize = pageSize; /de~+I5AB~
}
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publicint getTotalCount(){ 5fp&!HnG
return totalCount; =#%Vs>G
} =jU#0FAO
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publicvoid setTotalCount(int totalCount){ aLQ]2m
if(totalCount > 0){ sE^=]N
this.totalCount = totalCount; 3YEw7GIO-
int count = totalCount / H~0B5Hl!F
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pageSize; xp\6,Jyh
if(totalCount % pageSize > 0) h<!!r
count++; !\\1#:*_W
indexes = newint[count]; 3Z%jx#
for(int i = 0; i < count; i++){ &iJvkt
indexes = pageSize * RTL@WI
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i; }\W^$e-
} 0F&(}`V
}else{ `2HNQiK'@
this.totalCount = 0; <*ME&cgh4
} DM(c :+K-
} 'puiahA
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publicint[] getIndexes(){ bHzH0v]:
return indexes; cNl$
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} v0pev;C
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publicvoid setIndexes(int[] indexes){ LD}<|
this.indexes = indexes; Y1{*AV6ev6
} eTY(~J#'
]; B`'Ia
publicint getStartIndex(){ {iTA=\q2O
return startIndex; 5F1P|t#
} zZPXI&,
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publicvoid setStartIndex(int startIndex){ ^F|/\i
if(totalCount <= 0) ]"\sd"
this.startIndex = 0; Cs^'g'
elseif(startIndex >= totalCount) v%E!
this.startIndex = indexes aR%E"P-6l
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[indexes.length - 1]; MQo/R,F }
elseif(startIndex < 0) (<Kf
this.startIndex = 0; q]P$NeEiZ"
else{ uCf _O~
this.startIndex = indexes *p^*>~i9)
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[startIndex / pageSize]; /nNrvMtv
} 0?'v|5}
} /f! ze|
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publicint getNextIndex(){
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int nextIndex = getStartIndex() + NH8\}nAK
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pageSize; Sfffm$H
if(nextIndex >= totalCount) [nB4s+NX
return getStartIndex(); aByd,uSe)_
else R!RgQwEak
return nextIndex; 7JLjA\k
} |6Qn/N$+f
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publicint getPreviousIndex(){ JP6+h>ft
int previousIndex = getStartIndex() - e/<'HM T
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pageSize; -Dr)+Y
if(previousIndex < 0) aq.Lnbi/X
return0;
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else Iv>4o~t
return previousIndex; u 9kh@0
} JS(%:
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} :v 8~'cZ
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抽象业务类 c+G%o8
java代码: |SwW*C
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/** '/<f'R^
* Created on 2005-7-12 Hni?r!8r
*/
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package com.javaeye.common.business; s)7sgP
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import java.io.Serializable; x^6b$>1
import java.util.List; Q=F4ZrNqD
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import org.hibernate.Criteria; w72\'
import org.hibernate.HibernateException; G"F:68
import org.hibernate.Session; N/r8joi#
import org.hibernate.criterion.DetachedCriteria; aQL$?,
import org.hibernate.criterion.Projections; U
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import $5J~4B"%3
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org.springframework.orm.hibernate3.HibernateCallback; H.!\j&4j
import c7t .
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org.springframework.orm.hibernate3.support.HibernateDaoS Og9:MFI
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upport; &K-0ld(;
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import com.javaeye.common.util.PaginationSupport; \@GKVssw
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public abstract class AbstractManager extends FYX"q-Z
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HibernateDaoSupport { _|s'0F/t
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privateboolean cacheQueries = false; :o}LJc)|
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privateString queryCacheRegion; B1(T-pr
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publicvoid setCacheQueries(boolean L31#v$;4
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cacheQueries){ lD@`xq.M;
this.cacheQueries = cacheQueries; ;&ypvKG
} ko`.nSZ-k
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publicvoid setQueryCacheRegion(String C0
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queryCacheRegion){ %%hG],w
this.queryCacheRegion = ,p9>/)l
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queryCacheRegion; dNT<![X\
} G"nGaFT~
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publicvoid save(finalObject entity){ +VRM:&
getHibernateTemplate().save(entity); 9]PMti
} 2HF_kYZ
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publicvoid persist(finalObject entity){ XSe\@t~&g
getHibernateTemplate().save(entity); BFn4H%1
} b!c2j
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publicvoid update(finalObject entity){ ]T1\gv1~
getHibernateTemplate().update(entity); )5/,B-+O"
} $Lt'xW`8
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publicvoid delete(finalObject entity){ $`6Q\=*R/
getHibernateTemplate().delete(entity); cOvdC4
} s1%th"e
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publicObject load(finalClass entity, /DoSU>%hK
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finalSerializable id){ W9/HM !
return getHibernateTemplate().load }ISc^W) t
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(entity, id); f7oJ6'K
} ],l\HHQ
} @4by<
publicObject get(finalClass entity, TWSx9ii!M:
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finalSerializable id){ i.0.oy>
return getHibernateTemplate().get ['Y"6[1
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(entity, id); /#g
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} W*^_Ul|
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publicList findAll(finalClass entity){ wL~-k
return getHibernateTemplate().find("from HJt@m
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" + entity.getName()); n'qWS/0U=
} BKk+<#Ti
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publicList findByNamedQuery(finalString ,U?^u%
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namedQuery){ bO+]1nZ.
return getHibernateTemplate <KBS ;t="1
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().findByNamedQuery(namedQuery); $tB `dDj
} p&k%d, *
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publicList findByNamedQuery(finalString query, HJjx!7h
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finalObject parameter){ g<g$c<sm
return getHibernateTemplate -
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().findByNamedQuery(query, parameter); {iYrC m[_
} V-kx=M"k
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publicList findByNamedQuery(finalString query, _@OS,A
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finalObject[] parameters){ AwWo,Y399h
return getHibernateTemplate |./{,",
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().findByNamedQuery(query, parameters); 7\[)5j
} u{LtyDnik
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publicList find(finalString query){ 4)?s?+
return getHibernateTemplate().find uP$C2glyz
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(query); /z`.- D(
} |o<c`:;kt
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publicList find(finalString query, finalObject ;L[N.ZY!
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parameter){ jr/IU=u*v
return getHibernateTemplate().find "P
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(query, parameter); vOo-jUKs
} NK6~qWsu
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public PaginationSupport findPageByCriteria `PZcL2~E
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(final DetachedCriteria detachedCriteria){ \hI|I!sDWy
return findPageByCriteria 6G7+&g`
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); PFjh]/=
} =HjC.h
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public PaginationSupport findPageByCriteria `t3w|%La}
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(final DetachedCriteria detachedCriteria, finalint .S[M:<<*
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startIndex){ W/<Lp+p
return findPageByCriteria 9D]bCi\
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(detachedCriteria, PaginationSupport.PAGESIZE, @6b4YV
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startIndex); r-o+NV
} @cc}[Uw4B
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public PaginationSupport findPageByCriteria {9vMc
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(final DetachedCriteria detachedCriteria, finalint 2=7:6Fw
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pageSize, : +f6:3
finalint startIndex){ +]p/.-Uw
return(PaginationSupport) E]W
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getHibernateTemplate().execute(new HibernateCallback(){ + cZC$lo
publicObject doInHibernate O Ke
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(Session session)throws HibernateException { 8>`8p0I$+
Criteria criteria = 2=,d.1E3d
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detachedCriteria.getExecutableCriteria(session); cN`P5xP'
int totalCount = VFq7nV/O
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((Integer) criteria.setProjection(Projections.rowCount 1d OB|
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()).uniqueResult()).intValue(); mc4|@p*
criteria.setProjection f.0HIc
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(null); T?CQgVR
List items = jT`u!CwdT
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criteria.setFirstResult(startIndex).setMaxResults NjKC{L5S:
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(pageSize).list(); ']N\y6=fn9
PaginationSupport ps = 9M-W 1prb
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new PaginationSupport(items, totalCount, pageSize, 4U3 `g
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startIndex); Zt}b}Bz
return ps; -$I$z o
} EAHdt=8W{
}, true); 9Y?``QBN
} 5%+epzy
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public List findAllByCriteria(final .
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DetachedCriteria detachedCriteria){ ?*6Q;.f<
return(List) getHibernateTemplate ni6zo~+W]
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().execute(new HibernateCallback(){ N'0nt]&a
publicObject doInHibernate \H
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(Session session)throws HibernateException { ),H1z`c&I
Criteria criteria = <)
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detachedCriteria.getExecutableCriteria(session); SNf~%B?`L
return criteria.list(); &yI>A1
} Oj8D+sC{
}, true); &~'i,v|E
} jQ8
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public int getCountByCriteria(final 92~$Qa\S!
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DetachedCriteria detachedCriteria){ sGE%zCB
Integer count = (Integer) n g9_c
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getHibernateTemplate().execute(new HibernateCallback(){ `|mV~F|
publicObject doInHibernate c*i,z
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(Session session)throws HibernateException { op3a*KG
Criteria criteria = uQKo2B0
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detachedCriteria.getExecutableCriteria(session); wbI1~/
return AmJdZs|/
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criteria.setProjection(Projections.rowCount "LH3ZPD
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()).uniqueResult(); R
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} di7cCn
}, true); kOC0d,
return count.intValue(); 5Q: %f
} &da:{
} 'j!n
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用户在web层构造查询条件detachedCriteria,和可选的 PEaZ3{-
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 7Hj7b:3K&!
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PaginationSupport的实例ps。 E33WT{H&_'
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ps.getItems()得到已分页好的结果集 6$l?D^{
ps.getIndexes()得到分页索引的数组 24wr=5p]Q
ps.getTotalCount()得到总结果数 K[x=knFO
ps.getStartIndex()当前分页索引 KOoV'YSC[(
ps.getNextIndex()下一页索引 8idI Jm%y
ps.getPreviousIndex()上一页索引 @LSX@V
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 N^AlhR^
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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 /1uGsE+[
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一下代码重构了。 c= ?Tu
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我把原本我的做法也提供出来供大家讨论吧: JB=L{P J
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首先,为了实现分页查询,我封装了一个Page类: |?hsMN
java代码: NiQ Y3Nj
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/*Created on 2005-4-14*/ K@Xj)
package org.flyware.util.page; lkC| g%f
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/** JY,oXA6O
* @author Joa FlY"OU*
* j`K0D65
*/ ,?`kYPZ
publicclass Page { ly6dl
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/** imply if the page has previous page */ fwh/#V-i
privateboolean hasPrePage; R<%{I)
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/** imply if the page has next page */ ooP{Q r
privateboolean hasNextPage; o 9(x\g
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/** the number of every page */ O^ 5C
privateint everyPage; ;jO+<~YP!
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/** the total page number */ lR mVeq:
privateint totalPage; [nlq(DGJhp
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/** the number of current page */ p["pGsf
privateint currentPage; fI'+4
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/** the begin index of the records by the current ~yV?*"Hi
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query */ 1^ go)(Mx
privateint beginIndex; }lCQ+s!
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/** The default constructor */ G*~CB\K_
public Page(){ Xq "Es
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} BB ::zBg
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/** construct the page by everyPage Dtyw]|L\H
* @param everyPage 8i<]$
* */ c?aOX/C'
public Page(int everyPage){ jj]|}G
this.everyPage = everyPage; &