Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 8RU.}PD
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ~3d*b8
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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 "O``7HA}
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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
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分页支持类: Fv A8T2-v
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java代码: .lr5!Stb
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package com.javaeye.common.util; hJLT!33:
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import java.util.List; _ ~[M+IO
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publicclass PaginationSupport { %4/xH9
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publicfinalstaticint PAGESIZE = 30; W "k|K:
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privateint pageSize = PAGESIZE; Sz)b7:
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privateList items; x;(g
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privateint totalCount; *Dc@CmBr
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privateint[] indexes = newint[0]; fbV@= (y?
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privateint startIndex = 0; cWM:
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public PaginationSupport(List items, int 7f
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totalCount){ ^vM_kArA
setPageSize(PAGESIZE); #D0 ~{H
setTotalCount(totalCount); `O
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setItems(items); G1[(F`t>
setStartIndex(0); B!uxs
} He<;4?:
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public PaginationSupport(List items, int ]!faA\1
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totalCount, int startIndex){ `S$sQ&
setPageSize(PAGESIZE); t\%%d)d9
setTotalCount(totalCount); *:S~C
setItems(items); ,cD1{T\
setStartIndex(startIndex); L;lk.~V4T
} !5~k:1=
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public PaginationSupport(List items, int N<n8'XDdG
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totalCount, int pageSize, int startIndex){ |]tZ hI"3<
setPageSize(pageSize); Cm410 =b
setTotalCount(totalCount); I=odMw7Hj
setItems(items); 7>&1nBh. f
setStartIndex(startIndex); }LQ\a8]<
} $Elkhe]O %
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publicList getItems(){ ckWkZ
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return items; `M0YAiG
} (
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publicvoid setItems(List items){ Fv@tD4I>
this.items = items; U{HML|
} HzEGq,.
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publicint getPageSize(){ )#PtV~64
return pageSize; =y<0UU
} Gnv!]c&S>l
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publicvoid setPageSize(int pageSize){ [zx|eG<&-
this.pageSize = pageSize; GMe0;StT
} X Ny
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publicint getTotalCount(){ kC31$jMC3!
return totalCount; 0ERsMnU'
} sZwZWD'
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publicvoid setTotalCount(int totalCount){ }H2#H7!H
if(totalCount > 0){ 8JP6M!F#
this.totalCount = totalCount; FJF3B)Va|
int count = totalCount / ~QCA -Yud
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pageSize; .:[`j3s )Y
if(totalCount % pageSize > 0) b}}y=zO|$
count++; <p/MyqZf
indexes = newint[count]; M?R!n$N_
for(int i = 0; i < count; i++){ J^h'9iQpi
indexes = pageSize * FR["e1<0
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} 506V0]`/
}else{ F1J#Y$q~L
this.totalCount = 0; ydup)[n
} {lMqcK
} j-6v2MH
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publicint[] getIndexes(){ k% NrL@z
return indexes; .jaZ|nN8`
} >3!DOv
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publicvoid setIndexes(int[] indexes){ %Co
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this.indexes = indexes; #fN/LO
} L^)qe^%3
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publicint getStartIndex(){ zhjJ>d%w
return startIndex; zWtj|%ts
} PLdf_/]-
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publicvoid setStartIndex(int startIndex){ 7jT#BWt
if(totalCount <= 0) =E1tgrW
this.startIndex = 0; {KsVK4\r
elseif(startIndex >= totalCount) QY6O(=
this.startIndex = indexes Yw1Y-M
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[indexes.length - 1]; NA\ x<
elseif(startIndex < 0) +[_gyLN<5b
this.startIndex = 0; ?uig04@3
else{ $bFgsy*N2
this.startIndex = indexes #<UuI9
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[startIndex / pageSize]; u]0!|Jd0
} {zu/tCq?
} ,O2q+'&
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publicint getNextIndex(){ #r(a~
int nextIndex = getStartIndex() + m|mG;8}pI
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pageSize; w a2~C [
if(nextIndex >= totalCount) Hva{A
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return getStartIndex(); a}w&dE$!-
else pJn>oGeJ&
return nextIndex; Txu>/1N,
} `BpCRKTG
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publicint getPreviousIndex(){ 1 0V+OIC
int previousIndex = getStartIndex() - FbuKZp+
q 7`
pageSize; B6uf;Yc
if(previousIndex < 0) 9!cW
return0; oW8;^u
else f@L\E>t
return previousIndex; =@%MV(
} TD%WJ9K\
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} eiOi3q
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抽象业务类 WFXx70n
java代码: ${e -ffyy
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/** |NXFla
* Created on 2005-7-12 L^&do98
*/ 4">84,-N
package com.javaeye.common.business; N*?
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import java.io.Serializable; jD<9=B(g
import java.util.List; :ECw
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import org.hibernate.Criteria; oUCVd}wH
import org.hibernate.HibernateException; :%pw`b, =V
import org.hibernate.Session; wH#Lb@cfZ0
import org.hibernate.criterion.DetachedCriteria; |O2|`"7
import org.hibernate.criterion.Projections; L-SdQTx_
import ]2g5Ka[>w
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org.springframework.orm.hibernate3.HibernateCallback; :K?iNZqWN6
import j_hjCQ
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org.springframework.orm.hibernate3.support.HibernateDaoS qgh]@JJh
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upport; {XyG1
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import com.javaeye.common.util.PaginationSupport; ud5x$`
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public abstract class AbstractManager extends S|tA[klh
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HibernateDaoSupport { )_WH#-}
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privateboolean cacheQueries = false; *pmoLiuB>
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privateString queryCacheRegion; U. NeK{
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publicvoid setCacheQueries(boolean nvw NjN
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cacheQueries){ L>eQ*311
this.cacheQueries = cacheQueries; I):m6y@
} Z(#XFXd
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publicvoid setQueryCacheRegion(String X}kVBT1w+x
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queryCacheRegion){ 'Wd3`4V$
this.queryCacheRegion = jp"XS
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queryCacheRegion; K%o6hBlk_
} (8+.#1!*
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publicvoid save(finalObject entity){ d91I
getHibernateTemplate().save(entity); Sz^TGF
} PL9zNCr-[
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publicvoid persist(finalObject entity){ aU,0gvI(}
getHibernateTemplate().save(entity); zS#f%{
} }//8$Z<(
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publicvoid update(finalObject entity){ yOn H&Jj
getHibernateTemplate().update(entity); 5VCMpy
} bf&.rJ0
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publicvoid delete(finalObject entity){ ;F"
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getHibernateTemplate().delete(entity); zEnC[~W
} fq)Ohb
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publicObject load(finalClass entity, e/g<<f-
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finalSerializable id){ `HMligT
return getHibernateTemplate().load &6=TtTp"9
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(entity, id); <T4 7kL I
} ZdJVs/33Vn
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publicObject get(finalClass entity, E`
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finalSerializable id){ 5x93+DkO\
return getHibernateTemplate().get eUGmns
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(entity, id); 8+@1wks
} 8,Q.t7v
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publicList findAll(finalClass entity){ U)IsTk~}O
return getHibernateTemplate().find("from 9P,A
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" + entity.getName()); \{Ox@
} _"FbjQ"
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publicList findByNamedQuery(finalString M9ter&
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namedQuery){ $Sc08ro
return getHibernateTemplate QBN=l\m+
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().findByNamedQuery(namedQuery); soFvrl^Ql+
} @eAGN|C5
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publicList findByNamedQuery(finalString query, ~ ]m@k'n
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finalObject parameter){ qW` XA
return getHibernateTemplate .$}Z:,aB
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().findByNamedQuery(query, parameter); .3g\[p
} GSUOMy[M-
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publicList findByNamedQuery(finalString query, XQ+-+CD
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finalObject[] parameters){ !Ed<xG/
return getHibernateTemplate *cb
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().findByNamedQuery(query, parameters); s`$_
} qAuUe=w%p
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publicList find(finalString query){ %yS`C"ZQ)
return getHibernateTemplate().find [h2p8i'o
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(query); %3@RZe
} cE_Xo.:Y,
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publicList find(finalString query, finalObject x"h)"Y[c5
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parameter){ I_Mqh4];
return getHibernateTemplate().find 0
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(query, parameter); w$<fSe7
} ?6.KS
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public PaginationSupport findPageByCriteria .-1{,o/&Q
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(final DetachedCriteria detachedCriteria){ L{o >D"
return findPageByCriteria >>
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ;MdK3c
} q}7Df!<|
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public PaginationSupport findPageByCriteria {KQ-Ce-6
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(final DetachedCriteria detachedCriteria, finalint [b)K@Ha
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startIndex){ RE*S7[ge
return findPageByCriteria Ms$7E
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(detachedCriteria, PaginationSupport.PAGESIZE, 1PT_1[eAR
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startIndex); t9-\x
} Fy+7{=?^F
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public PaginationSupport findPageByCriteria E )Zd{9A5)
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(final DetachedCriteria detachedCriteria, finalint fU){]YP
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pageSize, ]6c2[r?g{
finalint startIndex){ %onAlf<$:^
return(PaginationSupport) uhN(`E@
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getHibernateTemplate().execute(new HibernateCallback(){ x.4)p6
publicObject doInHibernate `
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(Session session)throws HibernateException { "=5vgg3
Criteria criteria = <xh'@592
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detachedCriteria.getExecutableCriteria(session); .qU%SmQ^
int totalCount = Pt)}HF|u
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((Integer) criteria.setProjection(Projections.rowCount [ QL<&:s&
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()).uniqueResult()).intValue(); HI`A;G]
criteria.setProjection 2*",{m
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(null); PFn[[~5V
List items = 6s"bstc{
*]UEF_
criteria.setFirstResult(startIndex).setMaxResults . L6@Rs
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(pageSize).list(); >A@D;vx
PaginationSupport ps = >~bj7M6t
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new PaginationSupport(items, totalCount, pageSize, z(#hL-{c
9,a,A6xry
startIndex); 7J_f/st
return ps; YNQ6(HA
} vYm&AD
}, true); LkbvA
} ^DCv-R+p
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public List findAllByCriteria(final lL+^n~g
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DetachedCriteria detachedCriteria){ M>z7H"jCu
return(List) getHibernateTemplate Q1&dB{L
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().execute(new HibernateCallback(){ rls#gw
publicObject doInHibernate \rnG 1o
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(Session session)throws HibernateException { *L8HC8IbH
Criteria criteria = HkB<RsS$p_
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detachedCriteria.getExecutableCriteria(session); YaZ"&i
return criteria.list(); &-)Y[#\J
} r0uXMr=Z96
}, true); f?I *`~k
} %[CM;|?B4
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public int getCountByCriteria(final r%mTOLef
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DetachedCriteria detachedCriteria){ tNf" X!
Integer count = (Integer) A
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getHibernateTemplate().execute(new HibernateCallback(){ KcF+!;:
publicObject doInHibernate Q3{&'|}^2
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(Session session)throws HibernateException { 1Moh`
Criteria criteria = ,%G2>PBt
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detachedCriteria.getExecutableCriteria(session); /+U)!$zm*
return SpiC0
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criteria.setProjection(Projections.rowCount f0bV]<_9
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()).uniqueResult(); =v=!x
} yQ&%* ?J
}, true); 1b%7FrPkd
return count.intValue(); R'HA>?D
} \ OINzfbr
} Afl'-
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用户在web层构造查询条件detachedCriteria,和可选的 :R\v# )C
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 :Aiu!}\
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PaginationSupport的实例ps。 sBI%lrO
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ps.getItems()得到已分页好的结果集 ZTC1t_
ps.getIndexes()得到分页索引的数组 z6r/
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ps.getTotalCount()得到总结果数 ,PxQ[CGg
ps.getStartIndex()当前分页索引 w o9f99
ps.getNextIndex()下一页索引 qyfxT Q5
ps.getPreviousIndex()上一页索引 {S(T1ua
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 M 7$4KFNp
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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 PdBhX
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一下代码重构了。 dV
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我把原本我的做法也提供出来供大家讨论吧: QLg9aG|
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首先,为了实现分页查询,我封装了一个Page类: @23x;x
java代码: i_ T dI
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/*Created on 2005-4-14*/ Y\\nJuJo
package org.flyware.util.page; ') y~d
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/** ~ riw7"
* @author Joa Ih"Ol(W
* H;&t"Ql.
*/ .w)t<7 y
publicclass Page { %;?3A#
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/** imply if the page has previous page */ E=trJge
privateboolean hasPrePage; 6LQ O>k
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/** imply if the page has next page */ C;>Ll~f_
privateboolean hasNextPage; <Rt@z|Zv
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/** the number of every page */ nJg2O@mRJ
privateint everyPage; rM |RGe
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/** the total page number */ hh}EDnx
privateint totalPage; NZP,hAUK,
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/** the number of current page */ _,~zy9{,
privateint currentPage; f'U]Ik;Jy
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/** the begin index of the records by the current 'Y Zs6rcJ
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query */ 3Gv
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privateint beginIndex; &X(-C9'j
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/** The default constructor */ .5xg;Qg\Y
public Page(){ *JXJ
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} TKX# /
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/** construct the page by everyPage .`].\Zykf
* @param everyPage _R6> Ayw*
* */ mNKa~E
public Page(int everyPage){
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this.everyPage = everyPage; ~]W8NaQB(
} _jz=BRO$
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/** The whole constructor */ iN*@f8gf
public Page(boolean hasPrePage, boolean hasNextPage, bP@_4Dy
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int everyPage, int totalPage, _I!&w!3oM
int currentPage, int beginIndex){ kpu^:N&
this.hasPrePage = hasPrePage; (C%'I
this.hasNextPage = hasNextPage; i$bBN$<b<
this.everyPage = everyPage; H_FhHX.2(
this.totalPage = totalPage; sTz*tSwQv
this.currentPage = currentPage; Q<pM
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this.beginIndex = beginIndex; k~ue^^r}
} %?jf.p*kY
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/** rge/jE,^~Z
* @return %*nZ,r
* Returns the beginIndex. lOui{QU
*/ yNL71 >w4
publicint getBeginIndex(){ Sj?'T@
return beginIndex; VUb*,/hxa
} 7F4]EA^
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/** 8^lXM-G-
* @param beginIndex x3 S
* The beginIndex to set. Eqc$*=
*/ 4Q5v8k=
publicvoid setBeginIndex(int beginIndex){ G
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this.beginIndex = beginIndex; U9w*x/Swb
} |sh U
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/** [6|vx},N
* @return NL 37Y{b
* Returns the currentPage. hj4Rr(T
*/ %`'VXR?`h=
publicint getCurrentPage(){ RAC-;~$WB
return currentPage; cx|j
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} $/H'Dt6x
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/** zBbTj IFQ
* @param currentPage ?*4zNhL
* The currentPage to set. "^H+A-R[
*/ \<} nn?~n
publicvoid setCurrentPage(int currentPage){ L;"<8\vWB
this.currentPage = currentPage; jo^*R'}
} ?6dtvz;K+?
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/** DYS(ZY)4
* @return XHr{\/4V
* Returns the everyPage. :$j~;)2
*/ O 2U/zF:X
publicint getEveryPage(){ HD ~9EK~
return everyPage; pK4)>q
} ]^y}}y
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/** E !8y|_(j
* @param everyPage NmQ]qv
* The everyPage to set. 9O"?T7i"#
*/ J{y@ O
publicvoid setEveryPage(int everyPage){ T*IudxW
this.everyPage = everyPage; i,'~Ds
} yrjm0BM#
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/** |Xag:hof
* @return UTPl7po5D
* Returns the hasNextPage. i]nE86.;
*/ D1f=f88/}
publicboolean getHasNextPage(){ -n9e-0
return hasNextPage; HIF]c
} Aq"_hjp
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/** 89paR[
* @param hasNextPage 4v>V7T.
* The hasNextPage to set. uMI2Wnnc:/
*/ j!s&yHE1
publicvoid setHasNextPage(boolean hasNextPage){
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this.hasNextPage = hasNextPage; Y'-Lt5SCS
} O v-I2
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/** +FiV!nRkZ
* @return n'ro5D
* Returns the hasPrePage. DB0xIP~i,?
*/ G<-.{Gx)
publicboolean getHasPrePage(){ Z8T{Xw6%
return hasPrePage; 0pR04"`;
} 3
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/** a5'QL(IX
* @param hasPrePage "rXGXQu
* The hasPrePage to set. _VlNZ/V
*/ bYtF#Y
publicvoid setHasPrePage(boolean hasPrePage){ MiC&av
this.hasPrePage = hasPrePage; L4NC-
} a-3~HH
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/** U|zW_dj
* @return Returns the totalPage.
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* ?d%_o@
*/ 2d._X$fx7
publicint getTotalPage(){ 4=9F1[
return totalPage; DbcKKgPn(9
} qSQjAo4t@
8{ep`$(K@
/** O/k4W#
* @param totalPage !
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* The totalPage to set. K)qmJ-Gub
*/ t~AesHZpk
publicvoid setTotalPage(int totalPage){ yaf2+zV*
this.totalPage = totalPage; b &JPLUr
} gFKQm(0g2
Qu\E/T`
} p;@PfhEz)
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5}m2D='
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 8]Pf:_e,+
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个PageUtil,负责对Page对象进行构造: ~7ArH9k.
java代码: \z_@.Jw{
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/*Created on 2005-4-14*/ WMg#pLc#
package org.flyware.util.page;
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import org.apache.commons.logging.Log; PXkPC%j
import org.apache.commons.logging.LogFactory; Xbz}pAnj
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/** sK\?i3<?
* @author Joa _])1P?.
* +`[$w<I
*/ ?XHJCp;f
publicclass PageUtil { ?LZ)r^ger
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privatestaticfinal Log logger = LogFactory.getLog !XFN/-Q ,
i->sw#
(PageUtil.class); HP7Ec
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/** Fc=8Qt^
* Use the origin page to create a new page ht1
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* @param page U'\\(m|
* @param totalRecords =3}+f-6"'
* @return OxD\e5r
*/ !PO(Bfd
publicstatic Page createPage(Page page, int S"Efp/-
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totalRecords){ <q!{<(:
return createPage(page.getEveryPage(), >uQ!B/C!
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page.getCurrentPage(), totalRecords); 9`b*Y*d
} tp1{)|pwY6
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/** cJqPcCq(wn
* the basic page utils not including exception -Wmpj
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handler Oe5aNo
* @param everyPage (Q@m;i>
* @param currentPage o]]Q7S=
* @param totalRecords >LW9$[H
* @return page {!-w|&bF
*/ 6Fm.^9@
publicstatic Page createPage(int everyPage, int >6aCBS?2
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currentPage, int totalRecords){ = U^B,q
everyPage = getEveryPage(everyPage); Pg`^EJ+
currentPage = getCurrentPage(currentPage); 6!bf,T]
int beginIndex = getBeginIndex(everyPage, t rHj7Nw
p}j{<y
currentPage); I&^?,Fyy<
int totalPage = getTotalPage(everyPage, 5B(|!Xq;I
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totalRecords); x.d9mjLN8m
boolean hasNextPage = hasNextPage(currentPage, mX<D]Z< k
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totalPage); ]qXfgc
boolean hasPrePage = hasPrePage(currentPage); @]cpPW-b
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returnnew Page(hasPrePage, hasNextPage, !1!uB }
everyPage, totalPage, VB[R!S=
currentPage, *{C)o0D
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beginIndex); <H$ CCo
} ']qC,;2
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privatestaticint getEveryPage(int everyPage){ KYlWV<sR
return everyPage == 0 ? 10 : everyPage; 5uu{f&?u)
} +8~S28"Wg3
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privatestaticint getCurrentPage(int currentPage){ )>=`[$D1t
return currentPage == 0 ? 1 : currentPage; hwexv 9""
} #!<x|N?_<
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privatestaticint getBeginIndex(int everyPage, int SK-|O9Ki
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currentPage){ K7CiICe
return(currentPage - 1) * everyPage; xvgIYc{
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privatestaticint getTotalPage(int everyPage, int {(t (}-:Z
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totalRecords){ h>\}-|Ek
int totalPage = 0; !FO92 P16
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if(totalRecords % everyPage == 0) dso\+s
totalPage = totalRecords / everyPage; hR. EZ|.
else PUa~Apj'
totalPage = totalRecords / everyPage + 1 ; |=7%Edkd
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return totalPage; |Q7Ch]G
} (s}9N
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privatestaticboolean hasPrePage(int currentPage){ xNjA>S\]W5
return currentPage == 1 ? false : true; L*FnFRhU
} d*H-l3N
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privatestaticboolean hasNextPage(int currentPage, _msDf2e9
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int totalPage){ :CH'Bt4<
return currentPage == totalPage || totalPage == {Q4=GrS
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0 ? false : true; uD. 0?*_
} IMVoNKW-
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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。 EQ7cK63
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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 dedi6Brl
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做法如下: :Z&ipd!yY
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 }De)_E\~
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的信息,和一个结果集List: +K+
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java代码: fV[xv4D.
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/*Created on 2005-6-13*/ A~h8 >zz*
package com.adt.bo; `7'(U)x,F
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import java.util.List; W&r