Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 K <`>O,
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 *07sK1wW
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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 yFIIX=NC
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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 ~I_owCVZ
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分页支持类: -wr(vE,
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java代码: NCt~9xS.
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package com.javaeye.common.util; rFd@mO
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import java.util.List; Xq%*#)M;
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publicclass PaginationSupport { q\_DJ)qpn
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publicfinalstaticint PAGESIZE = 30; T0?uC/7H
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privateint pageSize = PAGESIZE; F,.Q|.nN
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privateList items; "B~WcC
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privateint totalCount; b24di
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privateint[] indexes = newint[0]; f@h2;An$w
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privateint startIndex = 0; 89db5Dx
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public PaginationSupport(List items, int @|E;}:?u
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totalCount){ {[my"n2
setPageSize(PAGESIZE); 87+.pM|t%
setTotalCount(totalCount); "-28[a3q
setItems(items); J-b~4
setStartIndex(0); prqyoCfq
} kv`3Y0R-"
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public PaginationSupport(List items, int {N8rZ [Oo
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totalCount, int startIndex){ /)HEx&SQmZ
setPageSize(PAGESIZE); (>/Dw|,m
setTotalCount(totalCount); @x\gk5
setItems(items); WW
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setStartIndex(startIndex); #p^pvdvh3
} EC&19
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public PaginationSupport(List items, int "\P~Re"EH
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totalCount, int pageSize, int startIndex){ .M#>@~XR
setPageSize(pageSize); -
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setTotalCount(totalCount); r:b.>5CS)
setItems(items); Lzb [%?
setStartIndex(startIndex); r_2VExk
} kA$;vbm
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publicList getItems(){ {hp@j#
return items; 5EZr"[8M
} w2_I/s6B
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publicvoid setItems(List items){ dXy"yQ>{
this.items = items; vt7C
} qQ\hUii
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publicint getPageSize(){ k-p7Y@`+a
return pageSize; i_9/!D
} h3ZL0Fi*
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publicvoid setPageSize(int pageSize){ j;c^pLUP
this.pageSize = pageSize; !)1Zp*
} ;C@^wI
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publicint getTotalCount(){ LGue=Hkp
return totalCount; LWR&(p.%
} 8c'-eT"
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publicvoid setTotalCount(int totalCount){ mr\L q~*c
if(totalCount > 0){ l3
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this.totalCount = totalCount; ;-w PXXR
int count = totalCount / ]uXsl0'`V
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pageSize; =Qq^=3@h
if(totalCount % pageSize > 0) "PP0PL^5F
count++; I ywx1ac
indexes = newint[count]; gG?*Fi
for(int i = 0; i < count; i++){ o*S $j Cf?
indexes = pageSize * ]qTr4`.
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} ^qy-el
}else{ X64I~*
this.totalCount = 0; SQ.Wj?W)
} uw&,pq
} V'4}9J
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publicint[] getIndexes(){ 9`VF
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return indexes; ph+tk5k
} jiD8|%}v
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publicvoid setIndexes(int[] indexes){ q/G5aO*
this.indexes = indexes; U~c;W@T
} s$G8`$+i1
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publicint getStartIndex(){ f.CI.aozW
return startIndex; a-hGpYJJG
} t9l7
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publicvoid setStartIndex(int startIndex){ %P6!vx:&^b
if(totalCount <= 0) \5_^P{p7<
this.startIndex = 0; ':dHYvP/UX
elseif(startIndex >= totalCount) (ytkq(
this.startIndex = indexes o\gQYi
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[indexes.length - 1]; 8hA=$}y&x
elseif(startIndex < 0) h}_q
this.startIndex = 0; k,(_R=
else{ Mb!^_cS(
this.startIndex = indexes B\yq%m
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[startIndex / pageSize]; <:?&}'aA
} <YC{q>EMc
} m +gVGK
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publicint getNextIndex(){ -Je+7#P1
int nextIndex = getStartIndex() + -Jhf]
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pageSize; E^g6,Y:i9
if(nextIndex >= totalCount) |:\h3M
return getStartIndex(); YXvKDw'95
else >,DR{A2hSB
return nextIndex; C oaqi`v4T
} Uc4r
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publicint getPreviousIndex(){ R{T4AZ@,'
int previousIndex = getStartIndex() - DT*/2TH*l
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pageSize; p'H5yg3h
if(previousIndex < 0) j1BYSfX'
return0; U}UIbJD*=
else As"'KR
return previousIndex; 2]@U$E='s
} 4o%hH
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} y"2c; *7[{
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抽象业务类 w'UP#vT5&
java代码: 9<R:)Df
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/** rIu>JyC"p
* Created on 2005-7-12 UOa{J|k>h
*/ &R 0BuFL8
package com.javaeye.common.business; Qc6323/"
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import java.io.Serializable; *{XbC\j
import java.util.List; d@C93VYp
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import org.hibernate.Criteria; NWTsL OIm
import org.hibernate.HibernateException; '06[@Cw
import org.hibernate.Session; AR&u9Y)I
import org.hibernate.criterion.DetachedCriteria; kg_TXB
import org.hibernate.criterion.Projections; ~x824xW
import ZVI.s U
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org.springframework.orm.hibernate3.HibernateCallback; e\\ I,
import q'PA2a:
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org.springframework.orm.hibernate3.support.HibernateDaoS H=B8'N
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upport; {AJspLcG
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import com.javaeye.common.util.PaginationSupport; >YD?
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public abstract class AbstractManager extends ,b2Cl[
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HibernateDaoSupport { 7QzUw
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privateboolean cacheQueries = false; !MoGdI-<r[
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privateString queryCacheRegion; )fv0H&g
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publicvoid setCacheQueries(boolean F?TAyD*
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cacheQueries){ ~p^6
this.cacheQueries = cacheQueries; Hcuvu[)T"
} Q!MS_
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publicvoid setQueryCacheRegion(String a3JG&6-
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queryCacheRegion){ 5^*I]5t8
this.queryCacheRegion = JuS#p5E #
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queryCacheRegion; eA4@)6W P(
} fC52nK&T8
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publicvoid save(finalObject entity){ =rGjOb3+
getHibernateTemplate().save(entity); BH0].-)[y!
} hgL wxJu
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publicvoid persist(finalObject entity){ D!+d]A[r
getHibernateTemplate().save(entity); b+9M? k"
} ^,qi`Tk
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publicvoid update(finalObject entity){ QJjqtOf>
getHibernateTemplate().update(entity); Q!iM7C!8
} l`4hWs\I
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publicvoid delete(finalObject entity){ [}} ?a
getHibernateTemplate().delete(entity); N*gnwrP{
} {}y"JbXMj
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publicObject load(finalClass entity, sEm-Td+A5
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finalSerializable id){ |VQ17*4ff1
return getHibernateTemplate().load .Cwgl
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(entity, id); aSkH<5i`v
} f.-b.nNf
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publicObject get(finalClass entity, -<h4I
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finalSerializable id){ 50q(8F-N
return getHibernateTemplate().get Ii FeO
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(entity, id);
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} #eadkj#;
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publicList findAll(finalClass entity){ jWL%*dJrN
return getHibernateTemplate().find("from @ /.w%
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" + entity.getName()); Uee(1
} Y6 <.]H
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publicList findByNamedQuery(finalString WhT5NE9t
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namedQuery){ m)l'i!Y
return getHibernateTemplate 1'B& e)
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().findByNamedQuery(namedQuery); ,Dab(
} :u]QEZ@@
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publicList findByNamedQuery(finalString query, 6e>P!bo
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finalObject parameter){ ;I9g;}
return getHibernateTemplate ;w7s>(ITZ
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().findByNamedQuery(query, parameter); (u4'*[o\t
} d`UK mj
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publicList findByNamedQuery(finalString query, p`2Q6
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finalObject[] parameters){ JU#m?4g
return getHibernateTemplate <Nk:C1Op}
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().findByNamedQuery(query, parameters); bU \T
} pAws{3(Q
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publicList find(finalString query){ >,ABE2t5
return getHibernateTemplate().find |>RNIJ]
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(query); K$l@0r ~k
} iR"6VO
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publicList find(finalString query, finalObject z=TOGP(
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parameter){ zR4]buHnE
return getHibernateTemplate().find f/QwXO-U
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(query, parameter); :uJHFF xg
} i;atYltEJ2
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public PaginationSupport findPageByCriteria g^}C/~b[
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(final DetachedCriteria detachedCriteria){ JZK93R
return findPageByCriteria +cbF$,M4
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); qRR%aJ/
} ^f57qc3nF
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public PaginationSupport findPageByCriteria vN:!{)~z
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(final DetachedCriteria detachedCriteria, finalint +f%"O?
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startIndex){ O._\l?m
return findPageByCriteria B&7NF}CF2
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(detachedCriteria, PaginationSupport.PAGESIZE, f5p/cUzX
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startIndex); 4AKr.a0q
} 9 *uK]/c
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public PaginationSupport findPageByCriteria p_
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(final DetachedCriteria detachedCriteria, finalint g*(z.
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pageSize, jO/cdLKX(
finalint startIndex){ * nFzfV
return(PaginationSupport) 6)p8BUft
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getHibernateTemplate().execute(new HibernateCallback(){ yXoNfsv
publicObject doInHibernate W9pY=9]p+
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(Session session)throws HibernateException { fm@Pa} ,
Criteria criteria = |d&C<O;f
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detachedCriteria.getExecutableCriteria(session); wJ pb$;
int totalCount = M.6uWwzQR
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((Integer) criteria.setProjection(Projections.rowCount Z'>UR.g
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()).uniqueResult()).intValue(); IG# wY
criteria.setProjection J5HN*Wd
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(null); LSA6*Q51
List items = Il9xNVos#
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criteria.setFirstResult(startIndex).setMaxResults sT"ICooc
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(pageSize).list(); (oR~%2K
PaginationSupport ps = [5p 3:D
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new PaginationSupport(items, totalCount, pageSize, Sir1>YEm
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startIndex); xGQP*nZ
return ps; &Z[+V)6,,
} S6(48/
}, true); C3Q #[
}
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public List findAllByCriteria(final xT_"` @
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DetachedCriteria detachedCriteria){ >qB`03>
return(List) getHibernateTemplate >J3mta3
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().execute(new HibernateCallback(){ y>x"/jzF#
publicObject doInHibernate n}F$kyI
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(Session session)throws HibernateException { x}pH'S7
Criteria criteria = TK18U*z7J
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detachedCriteria.getExecutableCriteria(session); XJPIAN~l
return criteria.list(); $(;Ts)P
} p@%Pdx
}, true); .tLRY
} H[p~1%Lq
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public int getCountByCriteria(final M&V4|D
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DetachedCriteria detachedCriteria){ ]:D&kTc
Integer count = (Integer) rgCC3TX
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getHibernateTemplate().execute(new HibernateCallback(){ fqbeO 9x
publicObject doInHibernate kVM*[<k
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(Session session)throws HibernateException { Z0zEX?2mb
Criteria criteria = q`{@@[/(y
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detachedCriteria.getExecutableCriteria(session); w^&UMX}
return qXq#A&
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criteria.setProjection(Projections.rowCount uKXU.u*C
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()).uniqueResult(); > `eo 0
} rU"AO}6\@
}, true); 4`#%<G
return count.intValue();
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} A@lM=
} rt vLLOIO
}])j>E
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用户在web层构造查询条件detachedCriteria,和可选的 wjX0r7^@
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 5?>Q[a.Ne
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PaginationSupport的实例ps。 2xuU[
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ps.getItems()得到已分页好的结果集 %`G}/"
ps.getIndexes()得到分页索引的数组 U/q"F<?.c
ps.getTotalCount()得到总结果数 QrmGrRH
ps.getStartIndex()当前分页索引 u{WI 4n?
ps.getNextIndex()下一页索引 u8A,f}D 3
ps.getPreviousIndex()上一页索引 nrpbQ(zI*
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 'zt}\ Dt
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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 +)(
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一下代码重构了。 fEK%)Z:0
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我把原本我的做法也提供出来供大家讨论吧: Sf`?j
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首先,为了实现分页查询,我封装了一个Page类: !qs~j=;y3
java代码: = p2AK\
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/*Created on 2005-4-14*/ 5X-d,8{w
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package org.flyware.util.page; Q?m= a0g
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/** ;x{J45^
* @author Joa uhmSp+%
* '! ;Xxe5
*/ ;ahI}}
publicclass Page { /LCRi
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/** imply if the page has previous page */ #k)J);&ZA
privateboolean hasPrePage; c30kb
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/** imply if the page has next page */ Bd13p_V"6
privateboolean hasNextPage; h4M>k{
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/** the number of every page */ |Tl2r,(+R
privateint everyPage; euh rEjwkH
Q
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/** the total page number */ \G]vTK3
privateint totalPage; 0_map z
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/** the number of current page */ 3:P "6mN
privateint currentPage; 1QuR7p
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/** the begin index of the records by the current 2`/p V0
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query */ z 4`H<Pn
privateint beginIndex; }&*,!ES*
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/** The default constructor */ _Nq7_iT0
public Page(){ 1{X ;&y
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} zz+[]G+"2m
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/** construct the page by everyPage r$Ck:Q}
* @param everyPage zc#aQ.
* */ 1
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public Page(int everyPage){ VpkkiN
this.everyPage = everyPage; UDz#?ZWnd
} 4!KUPgg
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/** The whole constructor */ #\fxU:z~r
public Page(boolean hasPrePage, boolean hasNextPage, {m+(j (6-
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int everyPage, int totalPage, %7~~*_G
int currentPage, int beginIndex){ =9JKg4I6
this.hasPrePage = hasPrePage; Xm2p<Xu8h
this.hasNextPage = hasNextPage; noa=wy
this.everyPage = everyPage; tk
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this.totalPage = totalPage; wfxg@<WR
this.currentPage = currentPage; k/ 9S
this.beginIndex = beginIndex; gjVKk
} !h0#es\
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/** >)3[CU,
* @return .:b|imgiv
* Returns the beginIndex. [nam H a
*/ RMx$]wn_
publicint getBeginIndex(){ !5P\5WF~Y
return beginIndex; q^_PR|
} czV][\5
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/** @sAT#[j
* @param beginIndex jCMr[ G=
* The beginIndex to set. CN$wlhs
*/ =hO0@w
publicvoid setBeginIndex(int beginIndex){ Wa{>R2h\
this.beginIndex = beginIndex; BQcrF{q
} ;9r `P_r
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/** <d GGH
* @return MS,J+'2
* Returns the currentPage. ozZW7dveU
*/ S) /(~
publicint getCurrentPage(){ >=|Dir
return currentPage; sW[8f
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} {AbQaw
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/** EQDsbG0x
* @param currentPage 3fJGJW!zu
* The currentPage to set. 9Xb,Swo~
*/ 5?+ECxPt
publicvoid setCurrentPage(int currentPage){ kB-%T66\
this.currentPage = currentPage; 29DYL
} zKr\S|yE
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/** 8_8r{a<xW
* @return 6-U+<[,x
* Returns the everyPage. Q}GsCmt=)O
*/ YPQ&hEu0
publicint getEveryPage(){ GAONgz|ZI
return everyPage; RG [*:ReB9
} .i[rd4MCK
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/** hu (h'
* @param everyPage }J27Y;Zp9
* The everyPage to set. n?vw|'(}
*/ 8?ldD
publicvoid setEveryPage(int everyPage){ ]J;pUH+u
this.everyPage = everyPage; Y !e
} iiS^xqSNCt
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/** s`W\`w}
* @return s&