Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 }DbE4"^K7
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Y|:YrZSC
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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 vcwK6G
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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 fQP,=
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分页支持类: +O4( a.
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java代码: 7pP+5&*
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package com.javaeye.common.util; P,U$ %C!
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import java.util.List; UP]1(S?
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publicclass PaginationSupport { ifvU"l
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publicfinalstaticint PAGESIZE = 30; E0<)oQ0Xa>
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privateint pageSize = PAGESIZE; zA,/@/'(
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privateList items; 'g~@"9'oe
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privateint totalCount; o)p[
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privateint[] indexes = newint[0]; u0g*O]Y
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privateint startIndex = 0; /LF3O~Go
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public PaginationSupport(List items, int fx]eDA|$e
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totalCount){ OT;cfkf7
setPageSize(PAGESIZE); -zTEL(r
setTotalCount(totalCount); M!#AfIyB
setItems(items); E23w *']
setStartIndex(0); NHAH#7]M&1
} A4
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public PaginationSupport(List items, int +aj^Cs1$
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totalCount, int startIndex){ SY|Ez!tU:N
setPageSize(PAGESIZE); uOre,AQR
setTotalCount(totalCount); ikIzhUWE
setItems(items); kZv*rWAm
setStartIndex(startIndex); 9ad6uTc
} C.(
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public PaginationSupport(List items, int k2.G%]j
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totalCount, int pageSize, int startIndex){ R1/q3x
setPageSize(pageSize); GG+5/hU
setTotalCount(totalCount); m!:.>y
setItems(items); -bm,:Iy!
setStartIndex(startIndex); v8~YR'T0`V
} ]L8q
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publicList getItems(){ vd(dNu&,<
return items; n/ AW?'
} e3g_At\
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publicvoid setItems(List items){ 7*;^UqGjz
this.items = items; C\A49q
} ,T{oy:rB
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publicint getPageSize(){ ~&KX-AC@
return pageSize; '?8Tx&}U8
} # 66e@
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publicvoid setPageSize(int pageSize){ Um\0i;7 ~4
this.pageSize = pageSize; 8U=A{{0p
} ;cLUnsB\
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publicint getTotalCount(){ 3S;N(A4
return totalCount; cix36MR_
} f?maa5S
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publicvoid setTotalCount(int totalCount){ ${>DhfF
if(totalCount > 0){ Sr"/-
this.totalCount = totalCount; fI]b zv;
int count = totalCount / qtY
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pageSize; F@EJtwLd5y
if(totalCount % pageSize > 0) >A=\8`T^
count++; (bvoF5%
indexes = newint[count]; nB&j
for(int i = 0; i < count; i++){ R04J3D|
indexes = pageSize * s i?HkJv5
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} t!t=|JNf{
}else{ 6v>z h
this.totalCount = 0; \igaQ\~
} oCuV9dA.
} Hm4bN\%
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publicint[] getIndexes(){ VDpxk$a
return indexes; DEtf(lW_
} {cR3.%wX
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publicvoid setIndexes(int[] indexes){ !=[>r'+3
this.indexes = indexes; 7=3O^=Q^Q
} Bm}iU~(Z`
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publicint getStartIndex(){ Q7(eq0na
return startIndex; SQE`
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} TGpSulg7
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publicvoid setStartIndex(int startIndex){ '\t7jQ
if(totalCount <= 0) O]ZC+]}/
this.startIndex = 0; ]nc2/S%
elseif(startIndex >= totalCount) ._,trb>o
this.startIndex = indexes 50Ad,mn<
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[indexes.length - 1]; JJ-i_5\q
elseif(startIndex < 0) U|?,N0%Z1
this.startIndex = 0; %w:'!X><
else{ t3>$|}O]t
this.startIndex = indexes =:/>6H1x
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[startIndex / pageSize]; >qpqQ;
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} 8K^f:)Qw
} De]^&qw(
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publicint getNextIndex(){ M2p<u-6
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int nextIndex = getStartIndex() + [pR)@$"k'
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pageSize; [+Un ^gD
if(nextIndex >= totalCount) o(Kcs-W2
return getStartIndex(); 9-93aC.|}
else Ux_<d?p
return nextIndex; GX5W^//}
} 2-s 7cXs
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publicint getPreviousIndex(){ S&01SX6
int previousIndex = getStartIndex() - [#Fg\2bq_y
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pageSize; rS,j;8D-
if(previousIndex < 0) xlw 2g<s
return0; p8>R#9
else (:OHyeNt
return previousIndex; ohsH 2]C
} qiU5{}
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}
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抽象业务类 waQtr,m)
java代码: l5HWZs^
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/** >h%\HMKk
* Created on 2005-7-12 n ,1tD
*/ 6(.H3bu
package com.javaeye.common.business; 1J'pB;.]s
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import java.io.Serializable; !qw4mN
import java.util.List; ,R}Z=w#
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import org.hibernate.Criteria; 2&x7W*
import org.hibernate.HibernateException; Z(UD9wY5m
import org.hibernate.Session; cAibB&`~
import org.hibernate.criterion.DetachedCriteria; ^jOCenE3
import org.hibernate.criterion.Projections; G4m4k
import &-4
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org.springframework.orm.hibernate3.HibernateCallback; Y%h}U<y
import |Ng"C`$oqv
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org.springframework.orm.hibernate3.support.HibernateDaoS 6F-JK1i
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upport; ,ey0:.!;
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import com.javaeye.common.util.PaginationSupport; B@-"1m~la?
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public abstract class AbstractManager extends B-dlm8gX
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HibernateDaoSupport { fkG##!
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privateboolean cacheQueries = false; }!=U^A)
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privateString queryCacheRegion; M5 `m.n<
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publicvoid setCacheQueries(boolean pg!`SxFD
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cacheQueries){ _NT[
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this.cacheQueries = cacheQueries; ~lk@6{`l|1
} ALAL( f`
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publicvoid setQueryCacheRegion(String pw;r 25
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queryCacheRegion){ /Zx8nx'{V
this.queryCacheRegion = 6qDfcs
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queryCacheRegion; o$\tHzB9!A
} pI5_Hg
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publicvoid save(finalObject entity){ Pxk0(oBX
getHibernateTemplate().save(entity); > [8#hSk
} S\b K+
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publicvoid persist(finalObject entity){ #]X2^ND47
getHibernateTemplate().save(entity); sbA2W~:
} D2)i3vFB
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publicvoid update(finalObject entity){ }1F6?do3&
getHibernateTemplate().update(entity); 9M]^l,
} |=u96G~N
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publicvoid delete(finalObject entity){ SXh?U,5u
getHibernateTemplate().delete(entity); %Gu][_.L
} Otxa<M+"
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publicObject load(finalClass entity, NhCAv+
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finalSerializable id){ ,S0UY):( A
return getHibernateTemplate().load Vq U|kv
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(entity, id); ;.AV;C"
} wsI5F&R,
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publicObject get(finalClass entity, tJz^DXqAc
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finalSerializable id){ Tm\OYYyk
return getHibernateTemplate().get "]UIz_^'`U
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(entity, id); ]\`w1'*
} *73AAA5LKa
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publicList findAll(finalClass entity){ 0:#7M}U
return getHibernateTemplate().find("from ZHcONYAr
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" + entity.getName()); {?y<%@
} )gjGG8Ee
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publicList findByNamedQuery(finalString _6LH"o3
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namedQuery){ XR<G}x
return getHibernateTemplate Qi"'bWX@
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().findByNamedQuery(namedQuery);
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} H<XlUCr_~+
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publicList findByNamedQuery(finalString query, :cb[M5c
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finalObject parameter){ 3r`<(%\
return getHibernateTemplate {>A
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().findByNamedQuery(query, parameter); {<r`5
} G_0)oC@Jl:
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publicList findByNamedQuery(finalString query, Q84t9b
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finalObject[] parameters){ g/!Otgfu
return getHibernateTemplate ff[C'
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().findByNamedQuery(query, parameters); ~n8F7
} VD9J}bgJ
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publicList find(finalString query){ /XN*)m
return getHibernateTemplate().find n-W?Z'H{r
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(query); *n,UOHlO
} J(^
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publicList find(finalString query, finalObject F46O!xb%
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parameter){ ;}f6Y['z
return getHibernateTemplate().find bYK]G+Ww
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(query, parameter); M{G$Pk8[
} jXtLo,km
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public PaginationSupport findPageByCriteria unpfA#&!"
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(final DetachedCriteria detachedCriteria){ ~ J %m
return findPageByCriteria b~F!.^7Q
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); )S#j.8P'B
} {;\%!I
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public PaginationSupport findPageByCriteria 3JTU^ -S<
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(final DetachedCriteria detachedCriteria, finalint E
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startIndex){ {Qm6?H
return findPageByCriteria ?F9hDLX
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(detachedCriteria, PaginationSupport.PAGESIZE, [l`^fnKt
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startIndex); s!NisF
} `I@)<d
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public PaginationSupport findPageByCriteria <
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(final DetachedCriteria detachedCriteria, finalint Pb*q;9
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pageSize, UP5%C;
finalint startIndex){ t]gq+ c Lo
return(PaginationSupport) G[y&`Qc)G
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getHibernateTemplate().execute(new HibernateCallback(){ -aC!0O y`
publicObject doInHibernate t7sUtmq
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(Session session)throws HibernateException { neK*jdaP
Criteria criteria = 2lX[hFa5
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detachedCriteria.getExecutableCriteria(session); 'M47'{7T
int totalCount = 2&suo!ig
{_": /A
((Integer) criteria.setProjection(Projections.rowCount P*}9,VoY
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()).uniqueResult()).intValue(); h 3eGq:!9
criteria.setProjection Xqc'R5Cw
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(null); aB/{ %%o
List items = WNCM|VUl
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criteria.setFirstResult(startIndex).setMaxResults jq7vOr-_g
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(pageSize).list(); /QV [N
PaginationSupport ps = u Eu6f
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new PaginationSupport(items, totalCount, pageSize, TJeou#=/
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startIndex); S(@*3]!q
return ps; _G_ &Me0
} kyp U&F
}, true); fQ2!sV
} GZxglU,3T
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public List findAllByCriteria(final Sn_z
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DetachedCriteria detachedCriteria){ u>JqFw1
return(List) getHibernateTemplate p,3go[9X:R
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().execute(new HibernateCallback(){ ~)WfJ
publicObject doInHibernate #L|JkBia
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(Session session)throws HibernateException { ~e,f )?
Criteria criteria = >DSNKU+j
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detachedCriteria.getExecutableCriteria(session); &':UlzG
return criteria.list(); /zChdjz
} 4SX3c:>
}, true); MR^umLM88
} N]3-L`t
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public int getCountByCriteria(final 'vqj5YTj
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DetachedCriteria detachedCriteria){ ?,A}E|jZ
Integer count = (Integer) kKFuTem_3
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getHibernateTemplate().execute(new HibernateCallback(){ 9q@z[+X
publicObject doInHibernate X}n&`y{/
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(Session session)throws HibernateException { _OyP>|L'
Criteria criteria = hfl%r9o
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detachedCriteria.getExecutableCriteria(session); ;EE{~
return hY4)W
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criteria.setProjection(Projections.rowCount [R@q]S/
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()).uniqueResult(); ;]l{D}
} 9RCB$Ka6X
}, true); q?e16M
return count.intValue(); 'l0eo' K
} ,}xpYq_/
} f 4
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用户在web层构造查询条件detachedCriteria,和可选的 ~/]\iOL
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 9.MGH2^L?
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PaginationSupport的实例ps。 b3CspBgC
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ps.getItems()得到已分页好的结果集 2V=FWuXC"
ps.getIndexes()得到分页索引的数组 Q(!}t"u
ps.getTotalCount()得到总结果数 &VZmP5Gv
ps.getStartIndex()当前分页索引 !h`cXY~w
ps.getNextIndex()下一页索引
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ps.getPreviousIndex()上一页索引 w<I5@)i|
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 $2 +$,:
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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 / ut~jf`
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一下代码重构了。 *x#&[>
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我把原本我的做法也提供出来供大家讨论吧: /v|68x6
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首先,为了实现分页查询,我封装了一个Page类: H(DVVHx
java代码: hK9t}NE.O
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/*Created on 2005-4-14*/ ]C!Y~
package org.flyware.util.page; 8g2-8pa{
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/** m_PrasZ>
* @author Joa ]<o.aMdV
* r-\T}e2Gz
*/ QB.*R? A
publicclass Page { ;?HZ,"^I
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/** imply if the page has previous page */ 'nj&}A'
privateboolean hasPrePage; fjK]m.w
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/** imply if the page has next page */ %RT6~0z
privateboolean hasNextPage; J!TK*\a2
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/** the number of every page */ {TxVRpiP{Z
privateint everyPage; :vgh
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/** the total page number */ HLyFyv\
privateint totalPage; hAxuZb7 ?
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/** the number of current page */ T$N08aju#
privateint currentPage; _QOOx+%*5
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/** the begin index of the records by the current LPm# 3U
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query */ 1l`s1C
privateint beginIndex; J9$]]\52s.
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/** The default constructor */ xjn8)C
public Page(){ zN8V~M;
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} :x*|lz[
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/** construct the page by everyPage }9+1<mT9a/
* @param everyPage dnWt\>6&
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* */ i&s=!`
public Page(int everyPage){ $M3A+6["H
this.everyPage = everyPage; )zc8bS
} GYb2m"a)
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