Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 dC}`IR
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 S-+M;@'Rl
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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 IaFr&
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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?Q+9Rmm`J
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。
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分页支持类: r.0oxH']
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java代码: Q+i\8RJ
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package com.javaeye.common.util; "8V{5e!%j'
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import java.util.List; *R% wUi
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publicclass PaginationSupport { }%{MPqg
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publicfinalstaticint PAGESIZE = 30; ^;F{)bmu+)
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privateint pageSize = PAGESIZE; dPjhq(8 zU
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privateList items; 2k#t
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privateint totalCount; ;+pOP |P=
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privateint[] indexes = newint[0]; !PUp>(
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privateint startIndex = 0; #k5#j4!b
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public PaginationSupport(List items, int ?a/n<V '
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totalCount){ ,ZI\dtl
setPageSize(PAGESIZE); 2H?d+6Pt3
setTotalCount(totalCount); ;BH>3VK
setItems(items); EEf ]u7
setStartIndex(0); Uz8hANN0_
} Qu{cB^Ga*
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public PaginationSupport(List items, int C>|@& o1
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totalCount, int startIndex){ i~qfGl p6)
setPageSize(PAGESIZE); #\If]w*j
setTotalCount(totalCount); qg,Nb
setItems(items); qJ[@:&:
setStartIndex(startIndex); a}.Y!O&
} ACBQ3
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public PaginationSupport(List items, int w.kCBDL
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totalCount, int pageSize, int startIndex){ @Hr+/52B
setPageSize(pageSize);
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setTotalCount(totalCount); zJ& b|L
setItems(items); /3^P_\,>f
setStartIndex(startIndex); xDrV5bg
} &^ I+s^\=
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publicList getItems(){ Ht=$] Px
return items; dhR(_
} )bWrd$X
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publicvoid setItems(List items){ a20w,
this.items = items; 8l xY]UT
} E5x]zXy4
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publicint getPageSize(){ N
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return pageSize; ?ei%RWo
} F ! )-|n}
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publicvoid setPageSize(int pageSize){ {fG|_+tl3o
this.pageSize = pageSize; {
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} {^&k!H2
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publicint getTotalCount(){ 2lz
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return totalCount; Yk>8g;<
} Lpm?#g uR
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publicvoid setTotalCount(int totalCount){ %aLCH\e
if(totalCount > 0){ <3#<I)#
this.totalCount = totalCount; 6D*chvNA;
int count = totalCount / R@ QQNYU.D
EX 9Z{xX
pageSize; 5^|"_Q#:
if(totalCount % pageSize > 0) 6:RMU
count++; "#XtDpGk
indexes = newint[count]; [#X|+M&u6
for(int i = 0; i < count; i++){ Q eK{MF
indexes = pageSize * '(9YB9 i
1#!@["
i; T:#S86m
} ;vUxO<cKFq
}else{ >r:X~XnRUj
this.totalCount = 0; "
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} 4.k`[q8
} _>Ln@
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publicint[] getIndexes(){ #`58F .
return indexes; Gy^FrF
} zW)gC9_|m-
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publicvoid setIndexes(int[] indexes){ )[ w&C_>]
this.indexes = indexes; x,-S1[#X;
} l qXc
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publicint getStartIndex(){ 7%tR&F -u
return startIndex; \AJS,QD
} .S6ji~;r
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publicvoid setStartIndex(int startIndex){ '2wCP
EC
if(totalCount <= 0) :B+Rg cqi
this.startIndex = 0; n`QO(pZ6+
elseif(startIndex >= totalCount) 6ZTaQPtm
this.startIndex = indexes q'2`0MRa
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[indexes.length - 1]; ~ ;XYwQ"
elseif(startIndex < 0) p}f-c
this.startIndex = 0; c G*(C
else{ 7
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this.startIndex = indexes iW;}%$lVX
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[startIndex / pageSize]; QK'`=MU
} To">DOt
} |""=)-5N
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publicint getNextIndex(){ 8T<@ @6`T
int nextIndex = getStartIndex() + @$EjD3Z-
quY "
pageSize; OZa88&
if(nextIndex >= totalCount) =hPG_4#
return getStartIndex(); qj`,qm
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else `,Xb8^M2
return nextIndex; z'T=]-
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} &0JK38(
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publicint getPreviousIndex(){ \hrrPPD1z
int previousIndex = getStartIndex() - 64h_1,U
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pageSize; gA{'Q\
if(previousIndex < 0) Oy:QkV9
return0; luibB&p1
else wKGogf[(%
return previousIndex; @81-kdTx
} is9}ePC7Xu
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} F OeVRq:#
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抽象业务类 I/Sv"X6E
java代码: gxI&f
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/** '!Hhd![\=|
* Created on 2005-7-12 >_-!zjO8u
*/ zIP[R):3&U
package com.javaeye.common.business; ud yAP>
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import java.io.Serializable; iD.0J/
import java.util.List; y+?=E g
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import org.hibernate.Criteria; S|~i>
import org.hibernate.HibernateException; {5U1`>
import org.hibernate.Session; UHr{
import org.hibernate.criterion.DetachedCriteria; 4g>1Gqv6
import org.hibernate.criterion.Projections; ,>&?ty9o
import f9vcf# 2
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org.springframework.orm.hibernate3.HibernateCallback; $<
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import #!w:_T%
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org.springframework.orm.hibernate3.support.HibernateDaoS ~^^!"-
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upport; |.y>[+Qb*
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import com.javaeye.common.util.PaginationSupport; >BJ2v=RA
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public abstract class AbstractManager extends \k|_&hG
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HibernateDaoSupport { o~Bk0V=
se~ *<5
privateboolean cacheQueries = false; ;n3uV`\
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privateString queryCacheRegion; 7J0 ^N7"o
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publicvoid setCacheQueries(boolean "B3iX@C
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cacheQueries){ "g
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this.cacheQueries = cacheQueries; x%b]ea
} p3V9ikyy
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publicvoid setQueryCacheRegion(String r$b:1 C~
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queryCacheRegion){ R g%R/p)C
this.queryCacheRegion = 2Som0T<2
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queryCacheRegion; sqm%iyC=q
} Q.j-C}a
ph Wc8[Q
publicvoid save(finalObject entity){ PFImqojHd
getHibernateTemplate().save(entity); ODM>Z8@W/
} o%kSR ]V|
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publicvoid persist(finalObject entity){ j zxf"X-
getHibernateTemplate().save(entity); @)aXNQY
} NUi{!<
^ %~Et>C
publicvoid update(finalObject entity){ -=-x>(pRW7
getHibernateTemplate().update(entity); >GdLEE'w
} S#dyRTmI
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publicvoid delete(finalObject entity){ yrxx+z|wR
getHibernateTemplate().delete(entity); {q5hF5!`)
} |_Naun=+~
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publicObject load(finalClass entity, "wc`fg"3
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finalSerializable id){ GQYtH#
return getHibernateTemplate().load Q1N,^71
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(entity, id); M]8eW
} j8D$/
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publicObject get(finalClass entity, 44/0}v]
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finalSerializable id){ dpc=yXg>"c
return getHibernateTemplate().get D7Rbho<
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(entity, id); T }8r;<P6
} ?kT~)k
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publicList findAll(finalClass entity){ EmBfiuX
return getHibernateTemplate().find("from 8V53+]c$Y
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" + entity.getName()); h!JjN$
} 0X S' v,|
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publicList findByNamedQuery(finalString nvUkbmZG#
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namedQuery){ >.k@!*
return getHibernateTemplate %n V@'3EI
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().findByNamedQuery(namedQuery); ' /@!"IXz
} ['9OGV\
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publicList findByNamedQuery(finalString query, W4] 0qp`\
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finalObject parameter){ 'Rar>oU
return getHibernateTemplate OU
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().findByNamedQuery(query, parameter); ={&TeMMA
} A=2nj
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publicList findByNamedQuery(finalString query, BYA=M*f
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finalObject[] parameters){ []]LyWk
return getHibernateTemplate D4x'
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().findByNamedQuery(query, parameters); 5xn0U5U
} ?eg@
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publicList find(finalString query){ 4j=@}!TBt
return getHibernateTemplate().find 9#=IrlV4
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(query); {<V|Gr
} <pa];k(IQL
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publicList find(finalString query, finalObject !C)>
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parameter){ TY{?4
return getHibernateTemplate().find EPUJa~4
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(query, parameter); 7$!Bq#
} Z;> aW;Wt
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public PaginationSupport findPageByCriteria K|' ]Hje\
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(final DetachedCriteria detachedCriteria){ ]r{#268
return findPageByCriteria oeqJ?1=!
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); $F'~^2
} &cv/q$W4
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public PaginationSupport findPageByCriteria kO\&mL&
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(final DetachedCriteria detachedCriteria, finalint r?{LQWP>e
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startIndex){ K Qy\l+\gM
return findPageByCriteria PYRwcJ$b\d
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(detachedCriteria, PaginationSupport.PAGESIZE, R=f5:8D<-
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startIndex); 6(;[ov1
} 'k) P(H
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public PaginationSupport findPageByCriteria 4w
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(final DetachedCriteria detachedCriteria, finalint HH7gT
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pageSize, NomK(%8m$
finalint startIndex){ ]$X=~>w
return(PaginationSupport) '3,JL!
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getHibernateTemplate().execute(new HibernateCallback(){ A=>6$L];'
publicObject doInHibernate .Sth
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${{
(Session session)throws HibernateException { 60gn`s,,
Criteria criteria = aQ3vG08L>
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detachedCriteria.getExecutableCriteria(session); 5_T>HHR6
int totalCount = #nL0Hx7]E
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((Integer) criteria.setProjection(Projections.rowCount T</gWW
SVeU7Q6-
()).uniqueResult()).intValue(); :)S4MoG
criteria.setProjection R3=E?us!
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(null); 0md{e`'q:
List items = , 0ja _
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criteria.setFirstResult(startIndex).setMaxResults 8i~'~/x
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(pageSize).list(); :Gk~FRA|
PaginationSupport ps = ;^SgV
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new PaginationSupport(items, totalCount, pageSize, LA3,e (e
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startIndex); Ft>8 YYyU
return ps; 6@361f[
} S;kc{?
}, true); %zVv3p:
} DEuW' .o>
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public List findAllByCriteria(final TuR?r`P%
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DetachedCriteria detachedCriteria){ EnAw8Gm*
return(List) getHibernateTemplate ;0{*V5A
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().execute(new HibernateCallback(){ $fG/gYvI\
publicObject doInHibernate :O=Vr]Y8K
(S{c*"}2
(Session session)throws HibernateException { e;\c=J,eE
Criteria criteria = AE~}^(G`
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detachedCriteria.getExecutableCriteria(session); 7]53GGNO
return criteria.list(); P_%l}%
} RGOwm~a
}, true); <\NXCUqDpo
} |]^! 4[!U
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public int getCountByCriteria(final nQMN2j M
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DetachedCriteria detachedCriteria){ l^Z~^.{y
Integer count = (Integer) /d;l:
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getHibernateTemplate().execute(new HibernateCallback(){ X ^)5O>>|t
publicObject doInHibernate }7^*%$
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(Session session)throws HibernateException { SJe;T
Criteria criteria = Wb$bCR#?<
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detachedCriteria.getExecutableCriteria(session); ObnB6ShKi
return j$Co-b1
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criteria.setProjection(Projections.rowCount ^hJ,1{o
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()).uniqueResult(); =$J2
} *O2j<3CHf
}, true); NmXTk+,L#
return count.intValue(); $tJJ
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} }P#gXG
} GW#Wy=(_
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用户在web层构造查询条件detachedCriteria,和可选的 YFY)Z7fK
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 1-fz564
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PaginationSupport的实例ps。 Bc@e;k@i
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ps.getItems()得到已分页好的结果集 gsAO<Fy
ps.getIndexes()得到分页索引的数组 >F
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ps.getTotalCount()得到总结果数 8jk*N
ps.getStartIndex()当前分页索引 #SmWF|/
ps.getNextIndex()下一页索引 #</yX5!V
ps.getPreviousIndex()上一页索引 @AFLF X]
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 -p }]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 /(w5S',EL
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一下代码重构了。 $A,=z
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我把原本我的做法也提供出来供大家讨论吧: 2= _.K(
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首先,为了实现分页查询,我封装了一个Page类: 3
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java代码: Ic*Q(X
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/*Created on 2005-4-14*/ q)/4i9
package org.flyware.util.page; C^a~)r.h
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/** '"&?u8u)
* @author Joa KK?}`o
* F{[Q
*/ 7Vi[I< *
publicclass Page { iR9iI!+;N
9}=Fdt
/** imply if the page has previous page */ e:#\Oh
privateboolean hasPrePage; cG<?AR?wDT
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/** imply if the page has next page */ hE;
privateboolean hasNextPage; >,[(icyzn
5o,82Kti
/** the number of every page */ 8ydOS
privateint everyPage; @M1U)JoQ
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/** the total page number */ uJ[dO}
privateint totalPage; a^22H
;RR)C@n1
/** the number of current page */ pCq{F*;
privateint currentPage; <v\|@@X
9]Y@eRI<
/** the begin index of the records by the current }}
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*ce h
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query */ G B15
privateint beginIndex; +iXA|L9=
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/** The default constructor */ WPPmh~:
public Page(){ ZY83,:<
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} kWgxswl7H
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/** construct the page by everyPage N(D_*% 96
* @param everyPage us/x.qPy2
* */ o/Z?/alt4
public Page(int everyPage){ 5[0n'uH
this.everyPage = everyPage; wqw$6"~
} c(o8uWn
rwU[dqBRhc
/** The whole constructor */ .7oz
public Page(boolean hasPrePage, boolean hasNextPage, 8tsW^y;S
rt f}4.
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int everyPage, int totalPage, |S/nq_g]
int currentPage, int beginIndex){ P!:D2zSH_
this.hasPrePage = hasPrePage; gzeG5p
this.hasNextPage = hasNextPage; n]|[|Rf1
this.everyPage = everyPage; &QvWT+]c'0
this.totalPage = totalPage; O4 [[9
this.currentPage = currentPage; .Zo8KwkFY
this.beginIndex = beginIndex; cBU>/
zIp
} S/8xo@vct]
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/** =*}|y;I
* @return NKO5c?ds
* Returns the beginIndex. CB|Z~_Bm
*/ 1SQ&mH/
publicint getBeginIndex(){ {eS!cZJ
return beginIndex; wF}/7b54
} \T>f+0=4
gzxLHPiw
/** lr=*Ty(V
* @param beginIndex Y*J,9
* The beginIndex to set. Y8(g8RN
*/ @va6,^)
publicvoid setBeginIndex(int beginIndex){ #VtlXr>G
this.beginIndex = beginIndex; 5ZUqCl(PX)
} K@ 6$|.bc
yo3'\I
/** BoXQBcG]w
* @return s@Y0"
* Returns the currentPage. C}%g(YRhb
*/ p^^E(<2
publicint getCurrentPage(){ L=?Yc*vg
return currentPage; ! p458~|
} &?v^xAr?B
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/** ^|(F|Z
* @param currentPage }"E?#&^
* The currentPage to set.
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*/ 7C
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publicvoid setCurrentPage(int currentPage){ C([TolZ
this.currentPage = currentPage; Bzw~OB{!=J
} V_$ BZm%8J
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/** /V^Gn;
* @return ['Hl$2 j
* Returns the everyPage. NN>,dd3T
*/ "o+<
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publicint getEveryPage(){ 4,`Yx s)%
return everyPage; Tm
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} `,3;#.[D
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/** nZ0-
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* @param everyPage X3P~z8_
* The everyPage to set. M| :wC
*/ oqc89DEbJ
publicvoid setEveryPage(int everyPage){ eF823cH2x_
this.everyPage = everyPage; @2na r<
} /PafIq
]6bh #N;.
/** [Abq("9p\
* @return 4"nb>tA
* Returns the hasNextPage. GWsvN&nr
*/ 4V@raI-
publicboolean getHasNextPage(){ c|.~f+
return hasNextPage; @GNNi?EY
} 0Ihp`QGU:
>hHjDYjbf
/** *](maF~%C
* @param hasNextPage ry)g<OA
* The hasNextPage to set. QpxRYv
*/ WhQK3hnm
publicvoid setHasNextPage(boolean hasNextPage){ b{%p
this.hasNextPage = hasNextPage; @ qy
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} 0}tf*M+a
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/** 094~ s
* @return jeXP|;#Una
* Returns the hasPrePage. :Aj8u\3!@
*/ 6Lj=%&
publicboolean getHasPrePage(){ lQ(I/[qVd
return hasPrePage; }-4@EC>
} tUU`R{=(
Yz7H@Y2i
/** pn"TFapJA
* @param hasPrePage r&!Ebe-
* The hasPrePage to set. $1lI6 =
,
*/ $]LhE:!G
publicvoid setHasPrePage(boolean hasPrePage){ i82sMN1jl7
this.hasPrePage = hasPrePage; 9bu}@#4*
} 3kqO5+,C
Xf
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/** jR1t&UD3Y
* @return Returns the totalPage. VgGMlDl
* ufl[sj%^|
*/ 7 6 nrDE
publicint getTotalPage(){ W3Gg<!*Uo
return totalPage; v\lhbpk
} ]]Bqte
oW
! Z=;
/** vX?MB
* @param totalPage O2;iY_P7lV
* The totalPage to set. J:D{5sE<|
*/ y0}3s)lKv
publicvoid setTotalPage(int totalPage){ py|ORVN(Z
this.totalPage = totalPage; X 8/9x-E_
} ??5y0I6+
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} #Sg< 9xsW
Q'
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b6(LoN.
V8KdY=[
1 sJtkge:
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 &[yW}uV<7
t_xO-fT)
个PageUtil,负责对Page对象进行构造: v79k{<Ln
java代码: SHow~wxw
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/*Created on 2005-4-14*/ s2Rg-:7
package org.flyware.util.page; &0`[R*S
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import org.apache.commons.logging.Log; 6 Mc&gnN
import org.apache.commons.logging.LogFactory; C}'Tmi
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/** 9B)<7JJX!J
* @author Joa X;/5Niv32q
* uD=FTx
*/ 1Zo"Xb
publicclass PageUtil { N\{{:<Cp\
wH0m^?a!3
privatestaticfinal Log logger = LogFactory.getLog L#|6Lnp^
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(PageUtil.class); fW3awR{
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/** t,]E5,1
* Use the origin page to create a new page sx^0*h-Qq
* @param page fbrCl!%P
* @param totalRecords 2kSN<jMr
* @return |& Pa`=sp
*/ ,9.-A-Yw
publicstatic Page createPage(Page page, int Dg=!d)\
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totalRecords){ $! R]!s
return createPage(page.getEveryPage(), ExxD
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page.getCurrentPage(), totalRecords); yx\I&\i
} `^mY*Cb e
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/** .|g|X8X
* the basic page utils not including exception TbQ5
/H'F4->
handler cii!
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* @param everyPage U9t-(`[j?
* @param currentPage g4f:K=5:
* @param totalRecords mmvo
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* @return page *Sw1b7l
*/ 7 (kC|q\4M
publicstatic Page createPage(int everyPage, int }UzRFIcv
p*C| kE qk
currentPage, int totalRecords){ P*:9u>
everyPage = getEveryPage(everyPage); lS96sjJp@
currentPage = getCurrentPage(currentPage); 0nsj ihw
int beginIndex = getBeginIndex(everyPage, lO/?e!$
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currentPage); ,a'Y^[4k?
int totalPage = getTotalPage(everyPage, 2H9;4>ss
_eZ*_H,\
totalRecords);
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boolean hasNextPage = hasNextPage(currentPage, 8nE}RD7bx
^_ST#fFS
totalPage); rHpxk
boolean hasPrePage = hasPrePage(currentPage); oY<R[NYKu
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returnnew Page(hasPrePage, hasNextPage, &rfl(&\oUi
everyPage, totalPage, 3R&
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currentPage, %3Tz%>n
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beginIndex); x%RG>),U
} 7'zXf)!
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privatestaticint getEveryPage(int everyPage){ kHb H{])
return everyPage == 0 ? 10 : everyPage; Wy.^1M/n>~
} gGE&}EoLU
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privatestaticint getCurrentPage(int currentPage){ wCgi@\
return currentPage == 0 ? 1 : currentPage; m <'&`B;
} s2`Qh9R
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privatestaticint getBeginIndex(int everyPage, int S!8gy,7<J
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currentPage){ h>"j!|#!s
return(currentPage - 1) * everyPage; hxZL/_n'
} -]Y@_T.C
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privatestaticint getTotalPage(int everyPage, int )skz_a}]8
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totalRecords){ n?:%>O s$
int totalPage = 0; %R^*MUTx
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if(totalRecords % everyPage == 0) Ctx`b[&KXX
totalPage = totalRecords / everyPage; >
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else Q.,2G7[ <
totalPage = totalRecords / everyPage + 1 ; }D[j6+E
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return totalPage; .$]-::&
} 7yQw$zG,Iz
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privatestaticboolean hasPrePage(int currentPage){ X]}:WGFM
return currentPage == 1 ? false : true; '81c>qA
} 9Cz|?71
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privatestaticboolean hasNextPage(int currentPage, iAo/Dnp2J
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int totalPage){ =2@V}
return currentPage == totalPage || totalPage == JbAmud,
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0 ? false : true; ^[6el_mj
} Y94S!TbB
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} &grqRt
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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。 S ,x';"
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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 24u_}ZQzY
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做法如下: l b;P&V
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 i5aY{3!
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的信息,和一个结果集List: OT0IGsJ"'
java代码:
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/*Created on 2005-6-13*/ wXtp(YwlH
package com.adt.bo; YmCu\+u
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import java.util.List; aS``fE;O
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import org.flyware.util.page.Page; hd]ts.
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/** [+_>g4M~%
* @author Joa ^HxIy;EQ<z
*/ pD('6C;
publicclass Result { 74 &q2g{
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private Page page; %lD+57=
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private List content; S9{A}+"K
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/** &B]1 VZUp
* The default constructor MT7B'hd
*/ 3I(;c ,S
public Result(){ \2]_NU5.
super(); w {"1V7|
} AVm+
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/** |-;VnC&UY
* The constructor using fields [(gXjt-
* \EsT1aT
* @param page Y%eq2%
* @param content $
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*/ i(_A;TT6
public Result(Page page, List content){ R1D ;
this.page = page; xH&hs$=
this.content = content; dOa9D
}
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/** ;1s+1G}_z
* @return Returns the content. i")0 3b
*/ L7d1)mV
publicList getContent(){ 7YR|6{@
return content; 1`YU9?
} *ziR &Fr!
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/** I/%v`[
* @return Returns the page. [:FiA?O]
*/ #c5jCy}n
public Page getPage(){ .] sJl
return page; tAF?.\x"g
} :8!RGtn
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/** ;8eKAh
* @param content *8WB($T}
* The content to set. Qr9;CVW
*/ Ps74SoD-
public void setContent(List content){ W*t]
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this.content = content; s4~[GO6>
} 'gvR?[!t
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/** Sk E <V0
* @param page 3f] ;y<Km
* The page to set. ^J5{quV
*/ MDU#V
publicvoid setPage(Page page){ dF\#:[B
this.page = page; BtZ]~S}v
} 1^4:l!0D
} viG,z4Zf
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