Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 wi
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 vBF9!6X .
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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 ug ;Xoh5w
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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 R"P-+T=7M
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分页支持类: +M_ _\7
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java代码: $S?gQN.e
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package com.javaeye.common.util; a oU"
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import java.util.List; E/%"%&`8j
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publicclass PaginationSupport { =_|G q|
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publicfinalstaticint PAGESIZE = 30; [yQ%g;m
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privateint pageSize = PAGESIZE; 23L>)Q
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privateList items; C7NSmZ
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privateint totalCount; YuknZ&Q
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privateint[] indexes = newint[0]; [tfB*m5
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privateint startIndex = 0; (iir,Ks2C
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public PaginationSupport(List items, int ' :B;!3a0d
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totalCount){ %wOkp`1-
setPageSize(PAGESIZE); Nv36#^Z
setTotalCount(totalCount); iUR ij@
setItems(items); Ri" hU/H{
setStartIndex(0); ur'<8pDb$
} |3,WiK='
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public PaginationSupport(List items, int \uPzj_kU6
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totalCount, int startIndex){ <YFDS;b|
setPageSize(PAGESIZE); 0 N>K4ho6{
setTotalCount(totalCount); o$.#A]Flb
setItems(items); 3jxC}xz)
setStartIndex(startIndex); 0!dNW,NfJ
} L>sLb(2\i
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public PaginationSupport(List items, int ^)>( <6
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totalCount, int pageSize, int startIndex){ `K.B`
setPageSize(pageSize); 8N'hG,
setTotalCount(totalCount); 'A:Y&w"r
setItems(items); uM[|>t
setStartIndex(startIndex); "V]*ov&[
} cHF W"g78
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publicList getItems(){ mv8H:T
return items; Wds>'zzS
} Pqya%j
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publicvoid setItems(List items){ ?(=|!`IoO
this.items = items; ^ul1{
} AEyD?^?
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publicint getPageSize(){ }/1^Lqfnz
return pageSize; u$%C`v>
} "t4z)j;
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publicvoid setPageSize(int pageSize){ '69)m~B0a
this.pageSize = pageSize; # atq7tX
} :[n~(~7?
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publicint getTotalCount(){ K _VIk'RB
return totalCount; ~wW]ntZm
} pE<a:2J
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publicvoid setTotalCount(int totalCount){ s|<n7 =J
if(totalCount > 0){ M{24MF
this.totalCount = totalCount; > "F-1{
int count = totalCount / C:Rs~@tl
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pageSize; Lbz/M_G
if(totalCount % pageSize > 0) #VX]trh,
count++; SnFyK5
indexes = newint[count]; 9y6u&!PZ\
for(int i = 0; i < count; i++){ - nNKUt.I
indexes = pageSize * GqCBD-@4v.
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} )'n@A% B
}else{ 8X`DFeJ
this.totalCount = 0; vOlfyH>
} 9]=J+ (M
} RM_%u=jC
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publicint[] getIndexes(){ UiV#w#&P
return indexes; QY)p![6Fj
} ASy?^Jrs5
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publicvoid setIndexes(int[] indexes){ moxmQ>xoH
this.indexes = indexes; tjThQ
} OlyW/hd
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publicint getStartIndex(){ +g?uvXC&
return startIndex; Gz{%Z$A~o
} ZOPK
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publicvoid setStartIndex(int startIndex){ PR|z -T
if(totalCount <= 0) y_L8i[
this.startIndex = 0; O1o>eDE5A
elseif(startIndex >= totalCount) zl8M<z1`1
this.startIndex = indexes (
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[indexes.length - 1]; "v?F4&\ 8
elseif(startIndex < 0) | I:@:
this.startIndex = 0; &mtt,]6C_
else{ <Mvniz
this.startIndex = indexes m BvO<?ec
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[startIndex / pageSize];
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} '/qy_7O
} !aUYidd
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publicint getNextIndex(){ fD[O
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int nextIndex = getStartIndex() + -B-G$ii
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pageSize; ~3M4F^
if(nextIndex >= totalCount) %bTuE' `b
return getStartIndex(); `Ns@W?
else \;MP|:{pU
return nextIndex; M *w{PjU
} AH n!>w,
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publicint getPreviousIndex(){ 0'6ai=W
int previousIndex = getStartIndex() - !0lk}Uzkh
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pageSize; 55s5(]`d
if(previousIndex < 0) QBXEM=
return0;
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else 5FJLDT2Lg
return previousIndex; BAXu\a-C_
} 2F*>&n&Db7
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} 8<}=f4vUj5
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抽象业务类 o@gceZuk
java代码: D+:s{IcL<
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/** F8<G9#%s\
* Created on 2005-7-12 0IqGy}+VU
*/ \E,2VM@6
package com.javaeye.common.business; <eMqg u
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import java.io.Serializable; 7+f6?
import java.util.List; ?"
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import org.hibernate.Criteria; xltN-<n7
import org.hibernate.HibernateException; [- 92]
import org.hibernate.Session; ?XdvZf $
import org.hibernate.criterion.DetachedCriteria; Nb:j]U
import org.hibernate.criterion.Projections; hd'fWFWN
import `XE>Td>Bs
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org.springframework.orm.hibernate3.HibernateCallback; k0=!%f_G!
import `lE&:)
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org.springframework.orm.hibernate3.support.HibernateDaoS `AE6s.p?
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upport; C)FO:lLr\
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import com.javaeye.common.util.PaginationSupport; oy
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public abstract class AbstractManager extends W=A0+t%XC
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HibernateDaoSupport { BMO,eQcB
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privateboolean cacheQueries = false; VtzZ1/JE
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privateString queryCacheRegion; 6R^F^<<
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publicvoid setCacheQueries(boolean [r>hKZU2
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cacheQueries){ <-N eusx%
this.cacheQueries = cacheQueries; [dLc+h1{B
} yB7si(,1>
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publicvoid setQueryCacheRegion(String 2X' H^t]7
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queryCacheRegion){ :T$}@& -
this.queryCacheRegion = =>PX~/o
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queryCacheRegion; >.P*lT
} j,].88H
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publicvoid save(finalObject entity){ _5n2'\] H`
getHibernateTemplate().save(entity); `2U,#nZ 4
} Eyf17
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publicvoid persist(finalObject entity){ *{5}m(5F
getHibernateTemplate().save(entity); 7ojh=imY
} exSwx-zxI
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publicvoid update(finalObject entity){ @Z$fEG)9
getHibernateTemplate().update(entity); J%ws-A?6rN
} W'k&DKhTqF
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publicvoid delete(finalObject entity){ nUONI+6Z/
getHibernateTemplate().delete(entity); .Sw4{m[g
} ;w%g*S
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publicObject load(finalClass entity, r{yIF~k@
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finalSerializable id){ HSG9|}$
return getHibernateTemplate().load hHw1<! M
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(entity, id); "OUY^ cM
} |OF3J,q
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publicObject get(finalClass entity, T2W^4)
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finalSerializable id){ 25, [<Ao
return getHibernateTemplate().get D0f7I:i1
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(entity, id); h*P0;V`UX
} *Z"Kvj;>u
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publicList findAll(finalClass entity){ cEJ_z(\=hr
return getHibernateTemplate().find("from Tig6<t+Q
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" + entity.getName()); Z#%77!3
} H'EBe;ccM
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publicList findByNamedQuery(finalString mn<ea&
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namedQuery){ A^c5CJ_
return getHibernateTemplate U8g?
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().findByNamedQuery(namedQuery); H~hAm
} SR)@'-Wd
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publicList findByNamedQuery(finalString query, v g tJ+GjN
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finalObject parameter){ [qt^gy)
return getHibernateTemplate kS7T'[d
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().findByNamedQuery(query, parameter); YX2j;Y?
} VxAR,a1+n
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publicList findByNamedQuery(finalString query, P#Ikj&l
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finalObject[] parameters){ |@)ij c4i
return getHibernateTemplate JeCEj=_Z
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().findByNamedQuery(query, parameters); -3b0;L&4>x
} xhMdn3~U
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publicList find(finalString query){ &jPsdv h
return getHibernateTemplate().find %nc+VL4
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(query); mKq9mA"(E
} ck<4_?1]
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publicList find(finalString query, finalObject E3KPJ`=!*"
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parameter){ %BHq2~J
return getHibernateTemplate().find Ap> n4~
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(query, parameter); \S2'3SDd/
} ->#7_W
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public PaginationSupport findPageByCriteria *'t`;m~
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(final DetachedCriteria detachedCriteria){ @',;/j80
return findPageByCriteria rC*n Z*
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); @+!d@`w:z2
} ?x/L"h&Kp
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public PaginationSupport findPageByCriteria E|Lh$9XONA
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(final DetachedCriteria detachedCriteria, finalint BPOWo8TqD^
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startIndex){ hg>YOf&RG
return findPageByCriteria Zj^H3h
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(detachedCriteria, PaginationSupport.PAGESIZE, QBo^{],
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startIndex); !%(B2J
} O&0R ~<n
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public PaginationSupport findPageByCriteria ?d%}K76V<
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(final DetachedCriteria detachedCriteria, finalint #WG(V%f]
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pageSize, jHZ<Gc
finalint startIndex){ ']NM_0
return(PaginationSupport) MG@19R2s
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getHibernateTemplate().execute(new HibernateCallback(){ _B[(/wY
publicObject doInHibernate _8>"&1n
),Rj@52l
(Session session)throws HibernateException { sOW|TN>y\
Criteria criteria = 3QVng^"B)
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detachedCriteria.getExecutableCriteria(session); >j?uI6Uw
int totalCount = o_5@R+&
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((Integer) criteria.setProjection(Projections.rowCount rG]Xgq"
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()).uniqueResult()).intValue(); T_dd7Ym'8
criteria.setProjection (qrT0D6
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(null); Z-?9F`}
List items = zl[JnVF\6
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criteria.setFirstResult(startIndex).setMaxResults $9~1s/('
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(pageSize).list(); -iHhpD9"X
PaginationSupport ps = 1DP)6{x
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new PaginationSupport(items, totalCount, pageSize, >>r:L3 <!
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startIndex); UK,P?_e
return ps; 11sW$@xs
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} O#\>j
}, true); #`$7$Y~]
} 86g+c
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public List findAllByCriteria(final >e ;f{
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DetachedCriteria detachedCriteria){ xTMTkVa+B
return(List) getHibernateTemplate %-Z~f~<?
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().execute(new HibernateCallback(){ cIp h$@
publicObject doInHibernate F e.*O`
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(Session session)throws HibernateException { MjTKM;
Criteria criteria = +IYSWR
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detachedCriteria.getExecutableCriteria(session); Bl];^W^P
return criteria.list(); cG:`Zj~4
} M'iKk[Hjfx
}, true); G
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} DG=Ap:sl*$
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public int getCountByCriteria(final ,be?GAq
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DetachedCriteria detachedCriteria){ H)Ge#=;ckQ
Integer count = (Integer) ;g
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getHibernateTemplate().execute(new HibernateCallback(){ nif'l/@"
publicObject doInHibernate bf/loMtD
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(Session session)throws HibernateException { rbbuSI
Criteria criteria = |$2N$6\SP
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detachedCriteria.getExecutableCriteria(session); {2r7:nvR
return ]H~,K ]@.
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criteria.setProjection(Projections.rowCount {1|7N
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()).uniqueResult(); QL18MbfqP
} ZS]f+}0/}
}, true); e622{dfVS
return count.intValue(); &Ld8Z9IeFp
} ^\jX5)2{
} PSS/JFZ^
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用户在web层构造查询条件detachedCriteria,和可选的 :~R
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 5G;^OI!g
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PaginationSupport的实例ps。 }A/&]1GWk
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ps.getItems()得到已分页好的结果集 eAKQR
ps.getIndexes()得到分页索引的数组 14!a)Ijl
ps.getTotalCount()得到总结果数 M;V#Gm
ps.getStartIndex()当前分页索引 ]f-'A>MC
ps.getNextIndex()下一页索引 4 ~YQ\4h=
ps.getPreviousIndex()上一页索引 X3iRR{< @
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 0*/ r'
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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 <;0N@
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一下代码重构了。 _QUu'zJ
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我把原本我的做法也提供出来供大家讨论吧: `m; "I
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首先,为了实现分页查询,我封装了一个Page类: (VPM>ndkw
java代码: >c\v&k>6.
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/*Created on 2005-4-14*/ V& j.>Y
package org.flyware.util.page; {e[pSD6
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/** 5OW8G][
* @author Joa $N+{r=
* O-!fOdX8_k
*/ 9_A0:S9Z
publicclass Page { H0b6ZA%n
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/** imply if the page has previous page */ R{xyme@"^
privateboolean hasPrePage; $ X=D9h
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/** imply if the page has next page */ E,D:D3O
privateboolean hasNextPage; kl3S~gE4@
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/** the number of every page */ _QMHPRELk
privateint everyPage; 90h1e7ZcC
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/** the total page number */ |RAQ% VXm
privateint totalPage; Wt)SdF=U/
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/** the number of current page */ bu"68A;>
privateint currentPage; ,F`KQ
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/** the begin index of the records by the current W]yClx \
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query */ [N95.aD
privateint beginIndex; 4j/ iG\
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/** The default constructor */ )_c=mT
public Page(){ 4/`h@]8P
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} mj(&`HRs4
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/** construct the page by everyPage eb.cq"C
* @param everyPage x'@32gv
* */ `Ge +(1x
public Page(int everyPage){ 4QjWZ Wl
this.everyPage = everyPage; ;la#Vf:]
} y3KcM#[
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/** The whole constructor */ 0Y6q$h>4
public Page(boolean hasPrePage, boolean hasNextPage, (
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int everyPage, int totalPage, 1A?\BJ"
int currentPage, int beginIndex){ |YE,) kiF
this.hasPrePage = hasPrePage; Tbi]oB#
this.hasNextPage = hasNextPage; CCW%G,$U9
this.everyPage = everyPage; UKKSc>D1
this.totalPage = totalPage; YH'$_,8peM
this.currentPage = currentPage; CrNwALx
this.beginIndex = beginIndex; up3?$hUc.
} uEScAeQXsI
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/** 3qAwBVWa
* @return ^zaKO'KcV
* Returns the beginIndex. C@y}*XV[b
*/ XdGpW
publicint getBeginIndex(){ Q5p+ W
return beginIndex; e$Xq
} RHwaJ;:)#
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/** m/YH^N0
* @param beginIndex >Lw}KO`
* The beginIndex to set. tjZ \h=
*/ Gh]_L+
publicvoid setBeginIndex(int beginIndex){ )YzH k ;(
this.beginIndex = beginIndex; 4AY
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} 0T9@,scY
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/** .
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* @return 2PVx++*]C
* Returns the currentPage. [!1)mR
*/ 3[0w+{(Q
publicint getCurrentPage(){ ;YK!EMM4!h
return currentPage; 7$!`p,@we/
} H+4=|mkQ
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/** G1kaF/`O
* @param currentPage s<A*[
* The currentPage to set. rQ9*J
*/ iD>G!\&