Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 LY0f`RX*&
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 y>=Y MD
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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 ?7NSp2aq2A
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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 ?L0;,
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分页支持类: lPZ>#
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java代码: 26/<\{q~
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package com.javaeye.common.util; ^"7-`<J
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import java.util.List; 1*p6UR&
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publicclass PaginationSupport { >fYcr#i0[
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publicfinalstaticint PAGESIZE = 30; ]<<,{IQ
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privateint pageSize = PAGESIZE; 9KX% O-'
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privateList items; UdrgUqq)
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privateint totalCount; 9.(|ri
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privateint[] indexes = newint[0]; >0@w"aKn
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privateint startIndex = 0; [lML^CYQ
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public PaginationSupport(List items, int 8|@) #:
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totalCount){ O^!ds
setPageSize(PAGESIZE); =-Hhm($n
setTotalCount(totalCount); ?<jWEz=
setItems(items); *DIY;)K
setStartIndex(0); 1Z
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} |9XoRGgXU
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public PaginationSupport(List items, int MUbKlX
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totalCount, int startIndex){ OB9E30
setPageSize(PAGESIZE); *@bz<{!
setTotalCount(totalCount); k~AtnI
setItems(items); eV!(a8
setStartIndex(startIndex); .'o=J`|
} Khd A;bF
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public PaginationSupport(List items, int {Y5@SIyE
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totalCount, int pageSize, int startIndex){ 1\,k^Je7
setPageSize(pageSize); Q4 &P\V
setTotalCount(totalCount); >"IG\//I
setItems(items);
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setStartIndex(startIndex); &Ih }"
} 4z P"h0
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publicList getItems(){ qN1fWU#$
return items; _O}U4aGMTC
} H.|I|XRG/
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publicvoid setItems(List items){ 3.Mpd
this.items = items; a$?d_BX
} <w}^Z}fpk&
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publicint getPageSize(){ ?i_/f} .K
return pageSize; 68GH$ji
} ZDaHR-%Y
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publicvoid setPageSize(int pageSize){ DcFY b|p
this.pageSize = pageSize; G*EF_N.G0
} l"[.Q>d
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publicint getTotalCount(){ C3^3<
return totalCount; p=UW ^95
} BZhf/{h[@
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publicvoid setTotalCount(int totalCount){ b=BNbmX
if(totalCount > 0){ x`+M#A()/
this.totalCount = totalCount; KsTGae;ds
int count = totalCount / d, g~.iS~
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pageSize; %JPr 7 }
if(totalCount % pageSize > 0) n~
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count++; Q)4[zStR#
indexes = newint[count]; -*[)CR-{
for(int i = 0; i < count; i++){ NG3:=
indexes = pageSize * <(TAA15Xol
;
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} ]U~{?K'g@j
}else{ k>MXOUaW.
this.totalCount = 0; 6(?@B^S>2
} dHOH]x
} E$ 8-8[
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publicint[] getIndexes(){ BQUYT/$(
return indexes; / QL<>g
}
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publicvoid setIndexes(int[] indexes){ `_/1zL[
this.indexes = indexes; M@q)\UQ'
} `ba<eT':
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publicint getStartIndex(){ t:lDFv4s
return startIndex; 0Z((cI\J
} Dz.kJ_"Ro
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publicvoid setStartIndex(int startIndex){ 8Dxg6>
if(totalCount <= 0) }Dcpe M?
this.startIndex = 0; z,C>Rh9Id
elseif(startIndex >= totalCount) >d
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this.startIndex = indexes V^D1:9i
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[indexes.length - 1]; nf_(_O=
elseif(startIndex < 0) LM"b%
this.startIndex = 0; WH $*\IGJL
else{ ;$!0pxL)s
this.startIndex = indexes uGlz|C
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[startIndex / pageSize]; 23;\l
} eon(C|S7eK
} Z^A( Q>{e
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publicint getNextIndex(){ ou|3%&*"
int nextIndex = getStartIndex() + b[n6L5P5m2
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pageSize; '@hnqcqXq
if(nextIndex >= totalCount) A-\n"}4
return getStartIndex();
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else D 5Z7?Y
return nextIndex; rY6bc\?`x
} Oh`Pf;.z%
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publicint getPreviousIndex(){ 2j>C4Ck
int previousIndex = getStartIndex() - zS?}3#g0u
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pageSize; ]%Whtj.,x7
if(previousIndex < 0) VJgf,
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return0; ZZ0b!{qj3
else C}XB%:5H5
return previousIndex; K}S=f\Q]
} +x:VIi
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} OnW,R3eg
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抽象业务类 giddM2'
java代码: OJcI0(G
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/** q*J-ii
* Created on 2005-7-12 kA 4kQ}q
*/ '_=XfTF
package com.javaeye.common.business; !Nhq)i
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import java.io.Serializable; |TBKsx8
import java.util.List; v}z{OB
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import org.hibernate.Criteria; )i.\q
import org.hibernate.HibernateException; zpxyX|
import org.hibernate.Session; ?v@q&
import org.hibernate.criterion.DetachedCriteria; );F
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import org.hibernate.criterion.Projections; @(tiPV
import ==7=1QfP
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org.springframework.orm.hibernate3.HibernateCallback; O~#OVFJ9=
import dI8y}EbE~
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org.springframework.orm.hibernate3.support.HibernateDaoS bzMs\rj\
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upport; w+ibY
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import com.javaeye.common.util.PaginationSupport; p7)b@,
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public abstract class AbstractManager extends QNm.8c$
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HibernateDaoSupport { _{?/4ZhA\+
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privateboolean cacheQueries = false; !}uev
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privateString queryCacheRegion; ?jBh=X\]:
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publicvoid setCacheQueries(boolean ^Ul*Nm
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cacheQueries){ .We"j_
}
this.cacheQueries = cacheQueries; !g-19at
} X=OJgyO/
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publicvoid setQueryCacheRegion(String OK9D4
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queryCacheRegion){ ODqWXw#
this.queryCacheRegion = 6JL:p{RLi
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queryCacheRegion; K_~SJbl
} [R[Suf
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publicvoid save(finalObject entity){ vV9q5Bj:
getHibernateTemplate().save(entity); YVLaO*(f
} V0WFh=CM@
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publicvoid persist(finalObject entity){ NCysYmt
getHibernateTemplate().save(entity); Ijj]_V{,
} 9Ic~F^
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publicvoid update(finalObject entity){ M%2F7 FY
getHibernateTemplate().update(entity); (Sg52zv
} "&/&v
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publicvoid delete(finalObject entity){ ^^Tu/YC9x
getHibernateTemplate().delete(entity); pb5'5X+
} 6,|)%~VUm
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publicObject load(finalClass entity, D ~Y3\KP
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finalSerializable id){ 0TI+6u
return getHibernateTemplate().load P}QuGy[
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(entity, id); J5Tl62}
} e$^ O_e
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publicObject get(finalClass entity, )#dP:
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finalSerializable id){ s],+]<qX
return getHibernateTemplate().get hQfxz,X
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(entity, id); K G~fDb
} =ITMAC\
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publicList findAll(finalClass entity){ B/Lx,
return getHibernateTemplate().find("from %!HmtpS
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" + entity.getName()); xla9:*pPn
} ;
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publicList findByNamedQuery(finalString v:<UbuJw
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namedQuery){ %fpcH
return getHibernateTemplate @&]j[if(s
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().findByNamedQuery(namedQuery); m(8t |~S
} , c/\'k\K)
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publicList findByNamedQuery(finalString query, cV5Lp4wY?
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finalObject parameter){ SD6xi\8
return getHibernateTemplate It4J\S
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().findByNamedQuery(query, parameter); EpCUL@+
} vGC^1AM
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publicList findByNamedQuery(finalString query, J%;TK6
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finalObject[] parameters){ kO\(6f2|x
return getHibernateTemplate y2^r.6"O
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().findByNamedQuery(query, parameters); ]RQQg,|D
} l9q
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publicList find(finalString query){ 9QI\[lT&
return getHibernateTemplate().find yU*j{>%RsK
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(query); ~^IS{1
} /z,sM"d
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publicList find(finalString query, finalObject +tOBt("5/
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parameter){ abCcZ<=|b
return getHibernateTemplate().find ?4_^}B9
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(query, parameter); &|26x
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} U\
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public PaginationSupport findPageByCriteria >NW
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(final DetachedCriteria detachedCriteria){ 3`k1
return findPageByCriteria ho@f}4jhQ3
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); *n2Q_o
} yIbz\3
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public PaginationSupport findPageByCriteria }jfU qqFd
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(final DetachedCriteria detachedCriteria, finalint C&3#'/&
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startIndex){ @k,u xe-
return findPageByCriteria Z%XBuq:BY
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(detachedCriteria, PaginationSupport.PAGESIZE, us4.-L
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startIndex); ^Q4w<sX'
} ||}|=Sz
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public PaginationSupport findPageByCriteria 1?)<*[
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(final DetachedCriteria detachedCriteria, finalint <k5FlvE2
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pageSize, r['T.yo
finalint startIndex){ 0d:t$2~C
return(PaginationSupport) ay'=M`uO_
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getHibernateTemplate().execute(new HibernateCallback(){ (OYR, [*
publicObject doInHibernate 6k42>e*p
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(Session session)throws HibernateException { \h :Rw|
Criteria criteria = Zo;@StN3}T
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detachedCriteria.getExecutableCriteria(session); *WfOB2rU
int totalCount = {j,bV6X
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((Integer) criteria.setProjection(Projections.rowCount %zd1\We
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()).uniqueResult()).intValue(); LZM[Wg#
criteria.setProjection .ymR%X_k
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(null); >?b/_O
List items = GfJm&'U&
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criteria.setFirstResult(startIndex).setMaxResults \@['V
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(pageSize).list(); `wB(J%w
PaginationSupport ps = j"_V+)SD
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new PaginationSupport(items, totalCount, pageSize, 1<<`T%&
qp
startIndex); "KW\:uc /
return ps; Y$Js5K@F
} KTBsH; 6
}, true); }.o
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} z6|P]u
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public List findAllByCriteria(final 5U3="L
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DetachedCriteria detachedCriteria){ #?!)-Q%
return(List) getHibernateTemplate (IIOKx _
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().execute(new HibernateCallback(){ !7AW_l9`i
publicObject doInHibernate ~e~4S~{
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(Session session)throws HibernateException { DD"]as"#
Criteria criteria = ' "~|L>F%G
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detachedCriteria.getExecutableCriteria(session); cEve70MV
return criteria.list(); w;}P<K
} '<>pz<c
}, true); UR1U; k
} `Kpn@Xg
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public int getCountByCriteria(final iW-w?!>|m
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DetachedCriteria detachedCriteria){ 3PpycJ}
Integer count = (Integer) 4}W*,&_
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getHibernateTemplate().execute(new HibernateCallback(){ HS="t3
publicObject doInHibernate $w)yQ %
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(Session session)throws HibernateException { dL |D
Criteria criteria = T.`E DluG
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detachedCriteria.getExecutableCriteria(session); w/~,mzM"
return -PBm@}*
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criteria.setProjection(Projections.rowCount ,wlFn
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()).uniqueResult(); DNLqipUw
} +a"MSPC4w
}, true); U$# ?Lw
return count.intValue(); .,o=#
} crz )F"
} (6^v`SZ
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用户在web层构造查询条件detachedCriteria,和可选的 4fT,/[k?
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 z4HIDb
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PaginationSupport的实例ps。 Q]S~H+eRy
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ps.getItems()得到已分页好的结果集 T4]/w|?G
ps.getIndexes()得到分页索引的数组 p^3]Q
ps.getTotalCount()得到总结果数 aqQ
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ps.getStartIndex()当前分页索引 cV\(Z6u
ps.getNextIndex()下一页索引 ~pO6C*"
ps.getPreviousIndex()上一页索引 b^~ keQ
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 12`q9Io"
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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 [CL.Xil=
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一下代码重构了。 =
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我把原本我的做法也提供出来供大家讨论吧: 9^6E>S{=
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首先,为了实现分页查询,我封装了一个Page类: K1>X%f^
java代码: S96H`kedZo
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/*Created on 2005-4-14*/ {; #u~e(W
package org.flyware.util.page; a8ya5EO
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/** O=~8+sa
* @author Joa 'n4Ro|kA
* 8mj Pa^A
*/ rH*1bDL
publicclass Page { I,TJV)B
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/** imply if the page has previous page */ q.0Evr:
privateboolean hasPrePage; zx` %)r
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/** imply if the page has next page */ )[fjZG[
privateboolean hasNextPage; Z/-9G
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/** the number of every page */ I> <B6pIR
privateint everyPage; NwAvxN<R(f
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/** the total page number */ ]Z\Z_t
privateint totalPage; (V&5EO8)
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/** the number of current page */ o\/&05rp]
privateint currentPage; &T.d"i
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/** the begin index of the records by the current L`'#}#O l
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query */ ` wI$
privateint beginIndex; G^r`)ND
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/** The default constructor */ j1zrjhXI
public Page(){ aE|'%72g
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} vHJOpQmt~
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/** construct the page by everyPage 5!QT
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* @param everyPage In[rxT~K}Q
* */ -L-#-dK'
public Page(int everyPage){ ]ilQq~X
this.everyPage = everyPage; (rmOv\hG9V
} A<h^.{
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/** The whole constructor */ r'J="^k{
public Page(boolean hasPrePage, boolean hasNextPage, *S xDwN
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int everyPage, int totalPage, L@5sY0 M
int currentPage, int beginIndex){ N#``(a
this.hasPrePage = hasPrePage; ?rm3Iac0S
this.hasNextPage = hasNextPage; _:N=
this.everyPage = everyPage; eOoqH$
i
this.totalPage = totalPage; i)iK0g"2
this.currentPage = currentPage; i:a*6b.U@N
this.beginIndex = beginIndex; zif&