Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 nCDG PzJ
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 )Lg~2]'?j
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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 'HJ<"<
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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 3QCCX$,
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分页支持类: X7txAp.
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java代码: !b?cY{
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package com.javaeye.common.util; ^qLesP#
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import java.util.List; S59^$
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publicclass PaginationSupport { HV{W7)
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publicfinalstaticint PAGESIZE = 30; NInZ~4:
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privateint pageSize = PAGESIZE; W9;9\k
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privateList items; Z|xgZG{
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privateint totalCount; ]IH1_?HgP7
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privateint[] indexes = newint[0]; xy4P_
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privateint startIndex = 0; ~9#'s'
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public PaginationSupport(List items, int cNMDI
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totalCount){ :Sn4Pg
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setPageSize(PAGESIZE); OVGB7CB]S
setTotalCount(totalCount); .:O($9^Ho
setItems(items); :r7!HG_
setStartIndex(0); !Y 9V1oVf"
} i,rX.K}X
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public PaginationSupport(List items, int -/:K.SY,
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totalCount, int startIndex){ KE-0/m4yJ
setPageSize(PAGESIZE); )hC3'B/[Y
setTotalCount(totalCount); e/x6{~ju^N
setItems(items); T.W^L'L`
setStartIndex(startIndex); lUdk^7:M
} tT+W>oA/M
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public PaginationSupport(List items, int VO~%O.>
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totalCount, int pageSize, int startIndex){ $,0EV9+af
setPageSize(pageSize); S~)_=4Z
setTotalCount(totalCount); .)<l69ZD Z
setItems(items); $4Dr +Z
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setStartIndex(startIndex); Z29LtKr
} ! F<::fN
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publicList getItems(){ -@@
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return items; IaKJ W?
} s1t kiX{>
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publicvoid setItems(List items){ !x!1H5"
this.items = items; bXA%|7*
} 5!aI~(3<
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publicint getPageSize(){ D=K{(0{"/,
return pageSize; G
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} AR{$P6u!%|
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publicvoid setPageSize(int pageSize){ >M0^R}v
this.pageSize = pageSize; <[$a7l i
} z#lIu
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publicint getTotalCount(){ Sjo-Xf}
return totalCount; BAi`{?z$<
} FAX[|p
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publicvoid setTotalCount(int totalCount){ nJ$2RN
if(totalCount > 0){ gX*j|(r
this.totalCount = totalCount; 0|g@;Pc
int count = totalCount / Yj'"Wg
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pageSize; -2'+GO7G
if(totalCount % pageSize > 0) CR;E*I${
count++; nw#AKtd@x
indexes = newint[count]; E!uQ>'iq.
for(int i = 0; i < count; i++){ D&i,`j
indexes = pageSize * U.h2 (-p
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i; ))<vCfuz2
} S9^SW3
}else{ 3Pp+>{2_?
this.totalCount = 0; h50]%tp\
} %V#MUi1
} Pz\ByD
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publicint[] getIndexes(){ CugZ!>;^
return indexes; )&Z`SaoP|J
} I8c:U2D
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publicvoid setIndexes(int[] indexes){ PjXiYc&
this.indexes = indexes; OUFy=5(%:
} 5z\,]
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publicint getStartIndex(){ \<dg
return startIndex; "zkQu
} $zF%F.rln
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publicvoid setStartIndex(int startIndex){ EPR85[k
if(totalCount <= 0) Q [C26U
this.startIndex = 0; h<bhH=6~
elseif(startIndex >= totalCount) ~gHn>]S0
this.startIndex = indexes P 00%EB
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[indexes.length - 1]; Vbe@S?u-
elseif(startIndex < 0) j@Pd"
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this.startIndex = 0; 7GS4gSd3
else{ %3AE2"
this.startIndex = indexes pvb&vtp
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[startIndex / pageSize]; %nG>3.%
} m*YfbOhs#
} FnI}N;"
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publicint getNextIndex(){ e\^}PU
int nextIndex = getStartIndex() + $ M/1pZ
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pageSize; q+2A>:|
if(nextIndex >= totalCount) `&'{R<cL
return getStartIndex(); #9Fk&Lx
else m )rVzL
return nextIndex; !m%'aQHH(
} NHe)$%a=H
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publicint getPreviousIndex(){ )l.uj
int previousIndex = getStartIndex() - +6$-"lf
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pageSize; o`!#io
if(previousIndex < 0) Lusd kc7
return0; ofw&?Sk0
else %d*0"<v
return previousIndex; l9OpaOVfJ
} 6VuyKt
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} }0Uh<v@
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抽象业务类 6\jbSe
java代码: 0
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/** R4P&r=?
* Created on 2005-7-12 >)G[ww[
*/ YllZ5<}
package com.javaeye.common.business; MkjB4:"
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import java.io.Serializable; <SQR";
import java.util.List; "\T-r 2
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import org.hibernate.Criteria; h::(b ,|f7
import org.hibernate.HibernateException; z^jmf_
import org.hibernate.Session; Q672iR\#)
import org.hibernate.criterion.DetachedCriteria; 43-Bx`6\
import org.hibernate.criterion.Projections; @YQ*a4`
import HFTeG4R
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org.springframework.orm.hibernate3.HibernateCallback; 9_F&G('V{a
import LI25VDZ|iP
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org.springframework.orm.hibernate3.support.HibernateDaoS 3$q#^UvD
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upport; QBH|pr
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import com.javaeye.common.util.PaginationSupport; /$]S'[5uF
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public abstract class AbstractManager extends <DPRQhNW]
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HibernateDaoSupport { 6<>1,wbq
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privateboolean cacheQueries = false; r_T"b
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privateString queryCacheRegion; nTGZ2C)c<'
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publicvoid setCacheQueries(boolean ,
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cacheQueries){ qV idtSb
this.cacheQueries = cacheQueries; &JKQH
} doe3V-if
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publicvoid setQueryCacheRegion(String 0Z]HH+Z;
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queryCacheRegion){ Ba5*]VGG
this.queryCacheRegion = O(2c_! d
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queryCacheRegion; wB'!@>db
} ,H,[)8
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publicvoid save(finalObject entity){ Y?7GFkIP$
getHibernateTemplate().save(entity); OFmHj]I7=
} LAnC8O
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publicvoid persist(finalObject entity){ @t1pB]O:
getHibernateTemplate().save(entity); q5hE S
} mSYm18
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publicvoid update(finalObject entity){ gq 3|vzNZ
getHibernateTemplate().update(entity); vu.?@k@
} V*fv>f:Yv
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publicvoid delete(finalObject entity){ L(cKyg[R
getHibernateTemplate().delete(entity); RSbq<f>BFo
} |<,0*2
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publicObject load(finalClass entity, q+oc^FD?@
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finalSerializable id){ 42tZBz&
return getHibernateTemplate().load k'N``.
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(entity, id); nK+ke)'Zv=
} 4e
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publicObject get(finalClass entity, !G[%; d
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finalSerializable id){ dI%ho<zm]
return getHibernateTemplate().get ma@V>*u
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(entity, id); R) dP=W*
} E@xrn+L>-
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publicList findAll(finalClass entity){ i^iu#WC
return getHibernateTemplate().find("from CadIux^
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" + entity.getName()); <)~-]
} _izjvg
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publicList findByNamedQuery(finalString bHx@
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namedQuery){ {47l1wV]
return getHibernateTemplate EK[J!~
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().findByNamedQuery(namedQuery); %`T}%B
} P7,g^:$
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publicList findByNamedQuery(finalString query, 9_jiUZFje
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finalObject parameter){ 3imsIBr
return getHibernateTemplate X<C fy
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().findByNamedQuery(query, parameter); SJh~4R\
} Hd\oV^>
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publicList findByNamedQuery(finalString query, w|S b`eR
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finalObject[] parameters){ Z : xb8]y
return getHibernateTemplate G'}N ?8s1
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().findByNamedQuery(query, parameters); I;E?;i
} Wu|MNB?M
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publicList find(finalString query){ KN657 |f
return getHibernateTemplate().find 'NCqI
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(query); & C)1(
} ,lvG5B\0
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publicList find(finalString query, finalObject uQx/o^
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parameter){ Keo<#Cc?
return getHibernateTemplate().find hF@%k
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(query, parameter); =fnBE`Uc
} n
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public PaginationSupport findPageByCriteria >2pxl(i
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(final DetachedCriteria detachedCriteria){ %]0?vw:;j
return findPageByCriteria et)n`NlcK
#|Lsi`]+
(detachedCriteria, PaginationSupport.PAGESIZE, 0); *'A*!=5(
} 'SlZ-SdR
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public PaginationSupport findPageByCriteria h6O'"
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(final DetachedCriteria detachedCriteria, finalint 0KgP'oWvY
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startIndex){ T!y 9v5
return findPageByCriteria EwV$2AK
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(detachedCriteria, PaginationSupport.PAGESIZE, ,C><n
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startIndex); lGR0-Gh2
} EZI#CLT[
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public PaginationSupport findPageByCriteria KU(BY}/ ^
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(final DetachedCriteria detachedCriteria, finalint aAGV\o{^
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pageSize, 3fQ`}OcNr
finalint startIndex){ `4xQ#K.-
return(PaginationSupport) YU[#4f~
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getHibernateTemplate().execute(new HibernateCallback(){ tl!dRV92
publicObject doInHibernate AQQa6Ce*
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(Session session)throws HibernateException { "~ $i#
Criteria criteria = @SxZ>|r-|v
:* ]#n
detachedCriteria.getExecutableCriteria(session); XK/l1E3N
int totalCount = j;y(to-e>D
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((Integer) criteria.setProjection(Projections.rowCount 4Ps;Cor+
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()).uniqueResult()).intValue(); =Jw*T[ E
criteria.setProjection Fs4shrt
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(null); 7~Inxk;
List items = W
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criteria.setFirstResult(startIndex).setMaxResults 'R-\6;3E>9
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(pageSize).list(); WUz69o be
PaginationSupport ps = 0vSPeZ
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new PaginationSupport(items, totalCount, pageSize, 5&EBUl}
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startIndex); 0<@['W}G
return ps; ,T
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} I|&DXF
}, true); T|BlFJ0"
} )=K8mt0qob
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public List findAllByCriteria(final ~%h
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DetachedCriteria detachedCriteria){ Ieq_XF]U
return(List) getHibernateTemplate :^{KY(3
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().execute(new HibernateCallback(){ UTu~"uCR
publicObject doInHibernate OwNM`xSa|\
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(Session session)throws HibernateException { YfT
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Criteria criteria = Z>y6[o
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detachedCriteria.getExecutableCriteria(session); qfCZ
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return criteria.list(); __tA(uA
} M"s:*c_6
}, true); !^MwE]
} ue7D'
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public int getCountByCriteria(final (#>X*~6
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DetachedCriteria detachedCriteria){ O-p`9(_m
Integer count = (Integer) DN=W2MEfc
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getHibernateTemplate().execute(new HibernateCallback(){ w$iPFZC'
publicObject doInHibernate :qj^RcmVPL
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(Session session)throws HibernateException { ESoC7d&.K{
Criteria criteria = 'Y
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detachedCriteria.getExecutableCriteria(session); ,Il) t H
return ^}vf
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criteria.setProjection(Projections.rowCount q+8de_"]
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()).uniqueResult(); [+b8
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} #0h}{y
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}, true); -U$;\1--
return count.intValue(); hTEb?1CXU
} [6g$;SicT
} J^#g?RHN>m
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用户在web层构造查询条件detachedCriteria,和可选的 T<Y*();Zo
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 s1[.L~;J
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PaginationSupport的实例ps。 ~cO iv
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ps.getItems()得到已分页好的结果集 .UX4p
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ps.getIndexes()得到分页索引的数组 5cA:;{z];g
ps.getTotalCount()得到总结果数 v]Pyz<+
ps.getStartIndex()当前分页索引 R%2.N!8v
ps.getNextIndex()下一页索引 7>MG8pf3a
ps.getPreviousIndex()上一页索引
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 9L-jlAo<
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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 SzeY?04zj:
P $y'``
一下代码重构了。 q4!\^HwQ
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我把原本我的做法也提供出来供大家讨论吧: dJrUcZBr
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首先,为了实现分页查询,我封装了一个Page类: ^uw]/H3?L
java代码: bnvY2-O6
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/*Created on 2005-4-14*/ t&x\@p9
package org.flyware.util.page; Z 369<
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co
/** W<^t2 j'
* @author Joa *6u2c%^
* znWB.H
*/ TT3GGHR
publicclass Page { PvW4%A@0
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/** imply if the page has previous page */ )+,h}XqlX
privateboolean hasPrePage; $f+I#uJ
+zDRed_]=_
/** imply if the page has next page */ zHNBX
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privateboolean hasNextPage; /G]/zlUE
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/** the number of every page */ S^D@8<6GJ
privateint everyPage; <?DI!~
4=y&}3om(0
/** the total page number */ as/PM"
privateint totalPage; Y%TY%"<
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/** the number of current page */ WO!OaC?+B,
privateint currentPage; _ 3>E+9TQ
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/** the begin index of the records by the current rqBoUS4
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query */ y}={S,z%22
privateint beginIndex; yeIS} O
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/** The default constructor */ dOaCdnd~
public Page(){ jbT{K|d-
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} ]^wr+9zd
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/** construct the page by everyPage %B1TN#KoT
* @param everyPage mv,a>Cvs[
* */ T <k;^iqR
public Page(int everyPage){ D-i, C~W
this.everyPage = everyPage; 6'uCwAQU
} X$Q.A^9
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/** The whole constructor */ a\,V>}e
public Page(boolean hasPrePage, boolean hasNextPage, NZ8X@|N
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int everyPage, int totalPage, y|0/;SjV
int currentPage, int beginIndex){ p0CPeH
this.hasPrePage = hasPrePage; WL,2<[)Ew
this.hasNextPage = hasNextPage; c8Q2H
this.everyPage = everyPage; ]b1>bv%
this.totalPage = totalPage; N|"kuRN#
this.currentPage = currentPage; +mR^ I$9
this.beginIndex = beginIndex; G*%U0OTi
} DYIp2-K
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/** ;P8%yf
* @return `YZl2c<w*
* Returns the beginIndex. tGXH)=K
*/ O/(vimx.#F
publicint getBeginIndex(){ c`S+>:
return beginIndex; {^;7DV:
} ?uJX
2Ir*}s2{
/** e$Yvy>I'tS
* @param beginIndex G^VOA4
* The beginIndex to set. Sj/v:
*/ F9las#\J
publicvoid setBeginIndex(int beginIndex){ -U9C{q?h
this.beginIndex = beginIndex; ku}`PS0UGd
} o>yXEg
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/** d,
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* @return # SJJ@SM
* Returns the currentPage. _"t>72
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*/ cCx{
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publicint getCurrentPage(){ ,-(D(J;}1
return currentPage; A yn$,
} p__N6a
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/** H;tE=
* @param currentPage \K%M.>]vq
* The currentPage to set. 1L7^g*
*/ y[AB,Dd
publicvoid setCurrentPage(int currentPage){ uD{ xs
this.currentPage = currentPage; s0x/2z
} =h
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/** ~>0H
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* @return i tk/1
* Returns the everyPage. ?0JNaf
*/ [^/a`Kda8
publicint getEveryPage(){ 2_M+o]Z^
return everyPage; }o[<1+W(.
} q j9q
{t|#>UCK
/** &^ s8V]^
* @param everyPage K@Q%NK,
* The everyPage to set. iG~&uEAJ
*/ @8A[HP
publicvoid setEveryPage(int everyPage){ }'>mT,ytgk
this.everyPage = everyPage; *W,[k&;:
} Hmx.BBz
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/** &u6n5-!v
* @return dmLx $8
* Returns the hasNextPage. !yq98I'
*/ /P]N40_@
publicboolean getHasNextPage(){ CM[83>
return hasNextPage; O2 + K
} vfm Y>nr
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/** EymSrZw
* @param hasNextPage w5/6+@}
* The hasNextPage to set. [>3dhj[;
*/ vW? /:
publicvoid setHasNextPage(boolean hasNextPage){ @B(E&
this.hasNextPage = hasNextPage; F:Ps>
} !su773vo
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/** El
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* @return +$2`"%nBG
* Returns the hasPrePage. m9&%A0
*/ ocUBSK|K)
publicboolean getHasPrePage(){ ov Xk~%_
return hasPrePage; o>Dd1
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} KQw>6)
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/** g:G5'pZf
* @param hasPrePage +bJ~S:[
* The hasPrePage to set. #,XZ @u+
*/ aX|(%1r
publicvoid setHasPrePage(boolean hasPrePage){ (FgX9SV]p9
this.hasPrePage = hasPrePage; MpJ<. |h
} q6>}
}? c%L8\
/** XAtRA1.
* @return Returns the totalPage. =9^}>u
* QF*cdc<
*/ e#3RT8u#
publicint getTotalPage(){ Acd@BL*
return totalPage; h5-yhG
} p
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/** m@w469&<(q
* @param totalPage RQ^
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* The totalPage to set. @'?gan#(
*/ a69e^;,>q
publicvoid setTotalPage(int totalPage){ $MfRw
this.totalPage = totalPage; ?<8c
} \ n^[!e"`
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} /<(-lbq,
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 s| Q1;%Tj
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个PageUtil,负责对Page对象进行构造: c813NHW
java代码: <X1lq9 lW
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/*Created on 2005-4-14*/ 19!;0fe=
package org.flyware.util.page; X(3| (1;sV
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import org.apache.commons.logging.Log; zn_#}}e;G
import org.apache.commons.logging.LogFactory; 7-~)/7L
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/** Wv;,@xTZ
* @author Joa ?.lo[X<,*
* DBLM0*B
*/ zpeCT3Q5O
publicclass PageUtil { d~h;|Bl[
pLV
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privatestaticfinal Log logger = LogFactory.getLog gG}H5uN
M7 kWJ
(PageUtil.class); a)Pr&9I
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/** 7n+,!oJ
* Use the origin page to create a new page _9p79S<+
* @param page d"Wuu1tEY
* @param totalRecords NuUiW*|`7
* @return z1^fG)
*/ 3G2iRr.o
publicstatic Page createPage(Page page, int Oe
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*,*O.#<6
totalRecords){ ~kSOYvK$'
return createPage(page.getEveryPage(), t*A[v
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page.getCurrentPage(), totalRecords); NJ-Ji> w
} T:H~Y+qnt
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/** >7~*j4g
* the basic page utils not including exception 4m"0R\
zH9*w:"4<_
handler .cw)Y#;IG
* @param everyPage hN]l
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* @param currentPage "+wkruC
* @param totalRecords S?C.:
* @return page iF837ng5
*/ op9vz[o#4
publicstatic Page createPage(int everyPage, int OJJ [Er1
w%\{4T~
currentPage, int totalRecords){ kS9;Tj cx
everyPage = getEveryPage(everyPage); Fu5Y<*x
currentPage = getCurrentPage(currentPage); T]zD+/=
int beginIndex = getBeginIndex(everyPage, Y Q.Xl_
lz36;Fp
currentPage); 8~s0%%{,M
int totalPage = getTotalPage(everyPage, d,Oagx
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totalRecords); %iEdU V\$
boolean hasNextPage = hasNextPage(currentPage, NqNU:_}
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totalPage); }HmkTk
boolean hasPrePage = hasPrePage(currentPage); P3Lsfi.
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returnnew Page(hasPrePage, hasNextPage, o|c6=77043
everyPage, totalPage, vf+z0df
currentPage, Hs:zfvD
[[6"qq
beginIndex); A|:+c*7]
} vq+CW?*"
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privatestaticint getEveryPage(int everyPage){ rBi<Yy$z
return everyPage == 0 ? 10 : everyPage; r `n|fD.
} {#4a}:3
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privatestaticint getCurrentPage(int currentPage){ XBkaum4j
return currentPage == 0 ? 1 : currentPage; [6JDS;MIN
} 7
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privatestaticint getBeginIndex(int everyPage, int eB1NM<V
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currentPage){ I9>vm]
return(currentPage - 1) * everyPage; &0%Zb~ts
} F --b,,
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privatestaticint getTotalPage(int everyPage, int ?<
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totalRecords){ Y;huTZ
int totalPage = 0;
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if(totalRecords % everyPage == 0) ]BjYUTNm
totalPage = totalRecords / everyPage; HQ"
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else S#B%[3@
totalPage = totalRecords / everyPage + 1 ; x$n.\`f0
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return totalPage; ipp`9 9
} X{,mj"(w
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privatestaticboolean hasPrePage(int currentPage){ N|2d9E
return currentPage == 1 ? false : true; a{^z= =
} ]w _&%mB
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privatestaticboolean hasNextPage(int currentPage, .FgeAxflP
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int totalPage){ Sk!' 2y*@&
return currentPage == totalPage || totalPage == T&>65`L
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0 ? false : true; Z$KyK.FUU
} %N~c9B
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} 7sOAaWx
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 YtSYe%
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 &&P9T/Zks
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做法如下: Q5Nbu90
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 3!gz^[!?EN
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的信息,和一个结果集List: { >[ ]iX
java代码: V61oK
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/*Created on 2005-6-13*/ ArAe=m!u
package com.adt.bo; JvW7h(u7g
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import java.util.List; ov,
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import org.flyware.util.page.Page; ro<w8V9.a
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/** OhCdBO
* @author Joa ojf6@p_
*/ JcmMbd&B
publicclass Result { a B MV6'
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private Page page; Eze w@*(
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private List content; UV}:3c6 ZX
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/** Kn5C
* The default constructor ">1wPq&
*/ T?!SEblP]
public Result(){ 1<#D3CXK
super(); Qfy_@w]
} YB 7A5
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/** :'ZR!w
* The constructor using fields uuFQTx))
* T|S-?X,
* @param page i7h^L)M
* @param content 4+d(d
*/ dS 4/spNq
public Result(Page page, List content){ +<xQF
this.page = page; URm<