Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 kBzzi^cl
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 v09f#t$;5
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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 m{*l6`dF
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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 xn"g_2Hi
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分页支持类: sR6(8
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java代码: YblRwic
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package com.javaeye.common.util; MWl@smRh
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import java.util.List; x\jHk}Buj
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publicclass PaginationSupport { Lg^m?~{
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publicfinalstaticint PAGESIZE = 30; [D t`@Dm
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privateint pageSize = PAGESIZE;
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privateList items; 1Jahu!c?
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privateint totalCount; nXN0~,+
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privateint[] indexes = newint[0]; >eC^]#c
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privateint startIndex = 0; _ReQQti[
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public PaginationSupport(List items, int 1)r1/0
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totalCount){ w
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setPageSize(PAGESIZE); rN}^^9
setTotalCount(totalCount); T>c;q%A/
setItems(items); ecHy. 7H
setStartIndex(0); Kz%wMyZ:g
} 4_mh
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public PaginationSupport(List items, int rh!4 1
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totalCount, int startIndex){ gs!{'=4wT
setPageSize(PAGESIZE); [J^,_iN[.
setTotalCount(totalCount); dI>oHMC
setItems(items); k@Hu0x
setStartIndex(startIndex); &8;mcM//4
} ENGw <
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public PaginationSupport(List items, int V=YK3){>A
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totalCount, int pageSize, int startIndex){ `S!`=26Z!
setPageSize(pageSize); +Kk6|+5u
setTotalCount(totalCount);
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setItems(items); 34oC285yc
setStartIndex(startIndex); oreSu;`$
} cZwQ{9>
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publicList getItems(){ %|;^[^7+}t
return items; WaHTzIa[
} i{`>!)U
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publicvoid setItems(List items){ GJ*AyYG
this.items = items; 'C[gcp
} rGN-jb)T+
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publicint getPageSize(){ ^=t yf&"
return pageSize; 6s Pd")%G
} @<};Bo'
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publicvoid setPageSize(int pageSize){ iBZ+gsSP
this.pageSize = pageSize; &o?pZ(\C
} kh`X92~
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publicint getTotalCount(){ Me8d o;
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return totalCount; J)R2O4OEd
} LJBoS]~
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publicvoid setTotalCount(int totalCount){ t >8t|t+
if(totalCount > 0){ bk8IGhO|m!
this.totalCount = totalCount; D.HAp+lx
int count = totalCount / >6aCBS?2
9/nL3 U@i1
pageSize; &;y(@e}D
if(totalCount % pageSize > 0) 4gYP .h:,
count++; I\[*vgjm3G
indexes = newint[count]; vbSz&+52;
for(int i = 0; i < count; i++){ >z(6ADq
indexes = pageSize * fxc~5~$>
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} +oyc9PoXF
}else{ &AoWT:Ea
this.totalCount = 0; TzIgEn~
} $mpfr#!&3o
} mX<D]Z< k
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publicint[] getIndexes(){ H\O|Y@uVr
return indexes; ok7DI
} V-jo2+Y5=
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publicvoid setIndexes(int[] indexes){ Uqkh@-6-
this.indexes = indexes; BG'gk#J+f
} %`` FIv15w
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publicint getStartIndex(){ //WgK{Mt
return startIndex; | o+vpy
} mhcJ0\@_
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publicvoid setStartIndex(int startIndex){ R
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if(totalCount <= 0) ~M <4HC
this.startIndex = 0; 7C&`i}/t
elseif(startIndex >= totalCount) #!<x|N?_<
this.startIndex = indexes u'=#~'6
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[indexes.length - 1]; q6osRK*20
elseif(startIndex < 0) K7CiICe
this.startIndex = 0; xvgIYc{
else{ N'^ 0:zK:
this.startIndex = indexes [V1gj9t=,
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[startIndex / pageSize]; >(\[ $
} ZkqC1u3
} ka]n+"~==\
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publicint getNextIndex(){ (2%C%#]8
int nextIndex = getStartIndex() + O*jNeYA
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pageSize; BL]^+KnP
if(nextIndex >= totalCount) S?D2`b
return getStartIndex(); ^%\p; yhL
else RI%*5lM8;
return nextIndex; P~?u2,.E[
} #ReW#?P%b/
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publicint getPreviousIndex(){ }p
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int previousIndex = getStartIndex() - h; {?z
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pageSize; (spX3n%p
if(previousIndex < 0) XLM 9+L
return0; S:DB%V3
else 2y,~i;;_
return previousIndex; ^ 41p+
} I]T-}pG
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} m@jOIt!<
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抽象业务类 J@1 (2%)|Z
java代码: Ef7Kx49I
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/** I</Nmgf
* Created on 2005-7-12 %d*}:295
*/ t7lRMCN
package com.javaeye.common.business; ,ll!19y
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import java.io.Serializable; G-rN?R.
import java.util.List; )m6=_q5@o
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import org.hibernate.Criteria; )TXn7{M:
import org.hibernate.HibernateException; #Xsby
import org.hibernate.Session; dU+1@_
import org.hibernate.criterion.DetachedCriteria; ,(lD5iN
import org.hibernate.criterion.Projections; Q}I. UG_
import K)^.96{/@
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org.springframework.orm.hibernate3.HibernateCallback; fDqlN`P@
import smk0 *m4
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org.springframework.orm.hibernate3.support.HibernateDaoS 23Eg|Xk
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upport; `.><$F
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import com.javaeye.common.util.PaginationSupport; L V9\
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public abstract class AbstractManager extends ^gv)[
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HibernateDaoSupport { ]Y,
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privateboolean cacheQueries = false; a)}?rzT]
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privateString queryCacheRegion; GT'%HmQI
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publicvoid setCacheQueries(boolean >a^H7kp
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cacheQueries){ .i`+} @iA
this.cacheQueries = cacheQueries; MLL2V`vBT
} hWuq
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publicvoid setQueryCacheRegion(String spAYb<
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queryCacheRegion){ _*&<hAZj
this.queryCacheRegion = qB"y'UW8
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queryCacheRegion; r\L:JTZ$
} 0z\=uQ0
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publicvoid save(finalObject entity){ 40+E#z)
getHibernateTemplate().save(entity); 48w3gye
} m@"!=CTKd
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publicvoid persist(finalObject entity){ \QYs(nm?k
getHibernateTemplate().save(entity); yKq;EcVx
} ];oED?I
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publicvoid update(finalObject entity){ drF"kTD"7
getHibernateTemplate().update(entity); \$9S_z
} V8&%f xn+
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publicvoid delete(finalObject entity){ Hs2L$TX
getHibernateTemplate().delete(entity); hZ$* sf
} n j1 cqh
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publicObject load(finalClass entity,
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finalSerializable id){ m|e!1_:H
return getHibernateTemplate().load At.WBa3j%{
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(entity, id); *:)#'cenI
} A@&+!sO
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publicObject get(finalClass entity, &>sG xK
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finalSerializable id){ KvC:(Vqj
return getHibernateTemplate().get }
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(entity, id); %`%1W
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} Fx)]AJ~[t
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publicList findAll(finalClass entity){ Cl i k
return getHibernateTemplate().find("from (z+[4l7
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" + entity.getName()); 9O P
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} nn5S 7!
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publicList findByNamedQuery(finalString 'U5
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namedQuery){ V/J[~mN9
return getHibernateTemplate 90teXxg=|
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().findByNamedQuery(namedQuery); ;/>~|@
} m6aoh^I
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publicList findByNamedQuery(finalString query, Po9 3&qE
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finalObject parameter){ o]PSyVg
return getHibernateTemplate N f1) 5
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().findByNamedQuery(query, parameter); In:h %4>
} $kkdB,y
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publicList findByNamedQuery(finalString query, wf<uG|90
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finalObject[] parameters){ j@2-^q:`
return getHibernateTemplate ukvz#hdE
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().findByNamedQuery(query, parameters); /vSFQ}W
} vqv(KsD+::
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publicList find(finalString query){ yu3EPT!~
return getHibernateTemplate().find CK'Cf{S
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(query); )Q FT$rmX
} ;k(|ynXv
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publicList find(finalString query, finalObject (f
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parameter){ j3sUZg|d
return getHibernateTemplate().find q>!T*BQ
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(query, parameter); ,Lox?}t
} uqX"^dn4u
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public PaginationSupport findPageByCriteria W $H8[G
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(final DetachedCriteria detachedCriteria){ uh`~K6&*\w
return findPageByCriteria TJLz^%t
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); V>4 !fD=
} ]wdudvS@6r
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public PaginationSupport findPageByCriteria *!'00fv
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(final DetachedCriteria detachedCriteria, finalint B=|yjA'Fg
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startIndex){ ~'v^__8
return findPageByCriteria NM[w =
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(detachedCriteria, PaginationSupport.PAGESIZE, F2>o"j2
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startIndex); q35%t61Lc
} B RD>q4w
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public PaginationSupport findPageByCriteria BYNOgB1
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(final DetachedCriteria detachedCriteria, finalint N[dhNK"
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pageSize, #^xiv/sV
finalint startIndex){ SYa!IL-B
return(PaginationSupport) Gd:fWz(
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getHibernateTemplate().execute(new HibernateCallback(){ YC*S;q
publicObject doInHibernate #H M0s~^w&
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(Session session)throws HibernateException { 9.SPxd~
Criteria criteria = f<0-'fGJd
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detachedCriteria.getExecutableCriteria(session); a+r0@eFLc
int totalCount = &[23DrI8
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((Integer) criteria.setProjection(Projections.rowCount 3u+~!yz
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()).uniqueResult()).intValue(); [$-y8`~(
criteria.setProjection zF\k*B
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(null); {9_CH<$W%U
List items = 0o(/%31]
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criteria.setFirstResult(startIndex).setMaxResults nJA\P1@m
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(pageSize).list(); ~(4cnD)BO
PaginationSupport ps = o`h F1*yp
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new PaginationSupport(items, totalCount, pageSize, /38^N|/Zr
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startIndex); `4(k ?Pk2
return ps; -zG/@.
} "mHSbG
}, true); fu\M2"e
} /1o~x~g(b
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public List findAllByCriteria(final '1/uf;OXIH
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DetachedCriteria detachedCriteria){ 8 :Z3Q
return(List) getHibernateTemplate 1_XdL?h#o
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().execute(new HibernateCallback(){ Sf
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publicObject doInHibernate b _cD
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(Session session)throws HibernateException { :2K0/@<x
Criteria criteria = Z`q?p E>R
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detachedCriteria.getExecutableCriteria(session); e9N"{kDs6
return criteria.list(); &YqgMC
} %3'80u6BCJ
}, true); o!\Vk~Vi&
} AGS?<6W-
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public int getCountByCriteria(final a|lcOU
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DetachedCriteria detachedCriteria){ 80
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Integer count = (Integer) dJ:EXVU
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getHibernateTemplate().execute(new HibernateCallback(){ ]NG`MZ
publicObject doInHibernate <E!M<!h
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(Session session)throws HibernateException { ~/iE
Criteria criteria = o;_v'
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detachedCriteria.getExecutableCriteria(session); kCLz@9>FQ
return XQHvs{Po
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criteria.setProjection(Projections.rowCount b!ot%uZZ
([tbFI}A
()).uniqueResult(); v#nYH?+~mJ
} EcBSi995dj
}, true); (A/V(.!
return count.intValue(); Lc0^I<Y
} G W|~sE +
} NFU 5+X-c
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用户在web层构造查询条件detachedCriteria,和可选的 IGOqV>;
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 :74)nbS
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PaginationSupport的实例ps。 vfcj,1
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ps.getItems()得到已分页好的结果集 YPFjAQ
ps.getIndexes()得到分页索引的数组 |SQ5 Sb
ps.getTotalCount()得到总结果数 Et4gRS)\
ps.getStartIndex()当前分页索引 .E"hsGH9h
ps.getNextIndex()下一页索引 shjS^CP
ps.getPreviousIndex()上一页索引 gGH<%nHW1
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 d^!)',`
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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 RU>T?2
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一下代码重构了。 -*M/,O
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我把原本我的做法也提供出来供大家讨论吧: K
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首先,为了实现分页查询,我封装了一个Page类: o}
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java代码: |!aMj8i2
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/*Created on 2005-4-14*/ @s b\0 }
package org.flyware.util.page; VSL6tQp
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/**
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* @author Joa {%)bxk6
* fnN"a Z
*/ gp$oQh#37;
publicclass Page { wtu WzHrF
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/** imply if the page has previous page */ $NWXn,Y'
privateboolean hasPrePage; N3!x7J7A
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/** imply if the page has next page */ hdXdz aNS
privateboolean hasNextPage; F)z]QJOw
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/** the number of every page */ `p|{(g'
privateint everyPage; -WWa`,:
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/** the total page number */ 2E9Cp
privateint totalPage; WSz#g2a
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/** the number of current page */ )}0(7z
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privateint currentPage; 4. 7m*
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/** the begin index of the records by the current RLu y;z
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query */ pd?3_yU
privateint beginIndex; BA4qQCS;5
ps\A\aggML
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/** The default constructor */ b%IRIi&,
public Page(){ m-xSF]q=<
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} ,edX;`#
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/** construct the page by everyPage F4xYfbwY"]
* @param everyPage R^.E";/h
* */ k|(uIU* ]
public Page(int everyPage){ F*_g3K!!
this.everyPage = everyPage; xc7Wk&{=
} wR@&C\}9
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/** The whole constructor */ <7NY.zvwk]
public Page(boolean hasPrePage, boolean hasNextPage, .DR^<Qy
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int everyPage, int totalPage, s.d }*H-o
int currentPage, int beginIndex){ W3Oj6R
this.hasPrePage = hasPrePage; 9lbe[w@
this.hasNextPage = hasNextPage; /GCI`hx>"
this.everyPage = everyPage; %JF.m$-
this.totalPage = totalPage; !B5 }`*1D
this.currentPage = currentPage; 56T<s+X>
this.beginIndex = beginIndex; +Wrj%}+
} T PEg>[
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/** *p0n{F9
* @return K;^$n>Y
* Returns the beginIndex. "#anL8
*/ D/[(}o(
publicint getBeginIndex(){ Nj4=
return beginIndex; -'ePx f
} 9y "R,
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/** z UN&L7D
* @param beginIndex | #Z+s-
* The beginIndex to set. sOQF_X(.x
*/ YC+}H33
publicvoid setBeginIndex(int beginIndex){ cy T,tN
this.beginIndex = beginIndex; Eh/B[u7T[
} `"`/_al^
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/** 7DQ{#Gf#G
* @return BV_rk^}Ur
* Returns the currentPage. ~5g2~.&*
*/ ' P5ttI#|
publicint getCurrentPage(){ zg L0v5vk
return currentPage; {=};<;_F
} Qk 2^p^ T6
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/** N.R,[K
* @param currentPage ?"-%>y@w
* The currentPage to set. ElLDSo@WvR
*/ -]HPDN,OB
publicvoid setCurrentPage(int currentPage){ j:ze5F A+
this.currentPage = currentPage; H <7r
} ntK#7(U'
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/** 6^_:N1@
* @return H&Jp,<\x
* Returns the everyPage. %zDh07VT\
*/ /=4 m4
publicint getEveryPage(){ ]'+PJdA
return everyPage; c4H5[LPF
} _nW{Q-nh
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/** {BB#Bh[
* @param everyPage 0*7N=
* The everyPage to set. lAYyxG#
*/ MtWzGE=?
publicvoid setEveryPage(int everyPage){ 36MqEUjyB
this.everyPage = everyPage; B q/<kEgM
} =LLix .
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/** G?Fqm@J{XT
* @return $hv o^$
* Returns the hasNextPage. gT3i{iU
*/ :K
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publicboolean getHasNextPage(){ )> >Tj7
return hasNextPage; phk fPvL{
} Am>^{qh9
rZ[}vU/H`
/** 4I&e_b< 30
* @param hasNextPage .%Pt[VQ
* The hasNextPage to set. 5MU-Eu|*>
*/ dZ]['y%
publicvoid setHasNextPage(boolean hasNextPage){ e0rh~@E
this.hasNextPage = hasNextPage; Qy< ~{6V
} ICq
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/** 9&]g2iT P
* @return qRk<1.
* Returns the hasPrePage. +q*Cw>t /
*/ B+)HDIPa-
publicboolean getHasPrePage(){ G_m$W3 zS
return hasPrePage; V!^5#A<
} 6ooCg>9/Z
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/** 9UbD=}W
* @param hasPrePage C|or2
* The hasPrePage to set. #>[BSgW
*/ .r=F'i}-j*
publicvoid setHasPrePage(boolean hasPrePage){ c_p7vvI&c0
this.hasPrePage = hasPrePage; 60R Yw9d%0
} T-.Q
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/** 8Qm%T7]UFb
* @return Returns the totalPage. }fqz8'E9
* 3y9R1/!
*/ I;u1mywd
publicint getTotalPage(){ <.d^jgG(j
return totalPage; IZw>!KYG
} VDnN2)Km*
,\".|m1o.
/** x~;1CB
* @param totalPage E![Ye@w
* The totalPage to set. ^/`W0kT
*/ G&7!3u
publicvoid setTotalPage(int totalPage){ qHQWiu%h
this.totalPage = totalPage; ;^yR,32F
} 4 C7z6VWg
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} n\/ JNzd3
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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 1ha
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个PageUtil,负责对Page对象进行构造: ~d.Z.AD
java代码: qL;T^lj P
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/*Created on 2005-4-14*/ [>MPM$9F-m
package org.flyware.util.page; agI"Kh]j?
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import org.apache.commons.logging.Log; /O*4/
import org.apache.commons.logging.LogFactory; =#z8CFq[O
#?^%#"~4H
/** ].(l^W
* @author Joa GE S_|[Q
* m,3H]
*/ x@aWvrL
publicclass PageUtil { :"im2J
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privatestaticfinal Log logger = LogFactory.getLog :U{$G(
<
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(PageUtil.class); p#QR^|7"
#'qDNY@ w}
/** 7]J7'!Iz
* Use the origin page to create a new page $URL7hrhU
* @param page LA9'HC(5
* @param totalRecords Ow3t2G
* @return O_S%PX
*/ |qAU\m"Pc
publicstatic Page createPage(Page page, int 1x'H#
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totalRecords){ 3_ P<0%
return createPage(page.getEveryPage(), Yvn*evO4
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page.getCurrentPage(), totalRecords); jl)7Jd
} =^5,ua6
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/** J? 4E Hl
* the basic page utils not including exception ^T< HD
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handler j=U^+jAn
* @param everyPage bd$``(b`v
* @param currentPage j8cXv
* @param totalRecords l'Kx#y$
* @return page x o{y9VS
*/ s~tZN
publicstatic Page createPage(int everyPage, int s9\N{ar#
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currentPage, int totalRecords){ t`!@E#VK
everyPage = getEveryPage(everyPage); oQ{
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currentPage = getCurrentPage(currentPage);
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int beginIndex = getBeginIndex(everyPage, x^XP<R{D
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currentPage); h(4&!x
int totalPage = getTotalPage(everyPage, zu!#
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totalRecords); t}X+P`Ovq
boolean hasNextPage = hasNextPage(currentPage, V/@7XAt
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totalPage); OTmw/ #ug
boolean hasPrePage = hasPrePage(currentPage); z[?&bF<|
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returnnew Page(hasPrePage, hasNextPage, G5T(
everyPage, totalPage,
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currentPage, nYE''g+x
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beginIndex); (/^dyG|X'
} 3;<Vv*a"Dm
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privatestaticint getEveryPage(int everyPage){
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return everyPage == 0 ? 10 : everyPage; `#c36
} JF6=0
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privatestaticint getCurrentPage(int currentPage){ r=4vN=:
return currentPage == 0 ? 1 : currentPage; *!c&[- g
} ,w|Or}h]7
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privatestaticint getBeginIndex(int everyPage, int wN2D{Jj
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currentPage){ A2p]BW&
return(currentPage - 1) * everyPage; ?C`&*+
} E06)&tF
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privatestaticint getTotalPage(int everyPage, int s)-O{5;U
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totalRecords){ Y$<p_X,
int totalPage = 0; ?d5_{*]+v
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if(totalRecords % everyPage == 0) o56UlN
totalPage = totalRecords / everyPage; iu.$P-s
else =jD9oMs
totalPage = totalRecords / everyPage + 1 ; E/{v6S{)Y
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return totalPage; D0*+7n3
} &, %+rvo}
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privatestaticboolean hasPrePage(int currentPage){ "Gc\"'^r
return currentPage == 1 ? false : true; DPBWw[
}
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privatestaticboolean hasNextPage(int currentPage, z`2Ais@ao
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(
int totalPage){ HvJ-P#
return currentPage == totalPage || totalPage == B{2WvPX~q
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0 ? false : true; ,UATT]>
} iNG =x
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} qE@H~&
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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。 rvRIKc|}l
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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 9|x{z
* amZ
做法如下: "YoFUfaNg
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Z11I1)%s
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的信息,和一个结果集List: +BgUnu26
java代码: LjY@b
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/*Created on 2005-6-13*/ @ev8"JZ1
package com.adt.bo; ~n{lu'SIX2
E, ;'n
import java.util.List; 5.U4P<