Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 'O_3)x5
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 LcTt)rs
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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 ':3pq2{
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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 P"IPcT%Ob%
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分页支持类: Rnr(g;2
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java代码: ~O
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package com.javaeye.common.util; RL@VSHXc
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import java.util.List; [ 0KlC1=
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publicclass PaginationSupport { J\:R|KaP<p
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publicfinalstaticint PAGESIZE = 30; [6%VRqY
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privateint pageSize = PAGESIZE; ;Q OBBF3HG
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privateList items;
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privateint totalCount; %,}A@H,
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privateint[] indexes = newint[0]; pz\
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privateint startIndex = 0; j7$e28|_n
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public PaginationSupport(List items, int {GK;63`1
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totalCount){ v1+3}5b'uF
setPageSize(PAGESIZE); wsZF;8u t
setTotalCount(totalCount); >~[c|ffyo/
setItems(items); H8Bs<2
setStartIndex(0); `>f6)C-
} (:TjoXXiY
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public PaginationSupport(List items, int S1Wj8P-
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totalCount, int startIndex){ :8=i kwQ
setPageSize(PAGESIZE); &_dt>.
setTotalCount(totalCount); {JZZZY!n2
setItems(items); aeFe!`F
setStartIndex(startIndex); 6}[I2F_^
} :cem,#(=
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public PaginationSupport(List items, int ([T>.s
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totalCount, int pageSize, int startIndex){ ;c-(ObSm
setPageSize(pageSize); K6v6ynp/
setTotalCount(totalCount); Wuc S:8#|
setItems(items); ZM!CaR
setStartIndex(startIndex); 9kN}c<o
} X0bN3N
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publicList getItems(){ S;3R S;
return items; GK)?YM
} BP'36?=Zo
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publicvoid setItems(List items){ NO "xL,
this.items = items; F\JM\{&F
} #>b3"[ |
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publicint getPageSize(){ I5 o)_nc
return pageSize; TJ_$vI
} &=Ar
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publicvoid setPageSize(int pageSize){ m4hX 'F
this.pageSize = pageSize; X@+{5%
} L-jJg,eY
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publicint getTotalCount(){ u)X=Qm)
return totalCount; ,&]S(|2%>t
} 3}TaF~
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publicvoid setTotalCount(int totalCount){ AK,J 7
if(totalCount > 0){ 4IB9,?p
this.totalCount = totalCount; p `8s
int count = totalCount / 0bceI
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pageSize; 8'r2D+Vwm
if(totalCount % pageSize > 0) 1n >X[!
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count++; AF;)#T<
indexes = newint[count]; rn/ /%
for(int i = 0; i < count; i++){ <r.)hT"0
indexes = pageSize * bR*-Ht+wd
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i; Y}t \4 di
} 1tEgl\u\
}else{ wKtl+}}
this.totalCount = 0; kw>v:F<M
} mq aHwID
} rHC>z7+z.
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publicint[] getIndexes(){ c(3~0Yr
return indexes; ]e"=$2d$
} 9TgIB
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publicvoid setIndexes(int[] indexes){ CY
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this.indexes = indexes; KSbKEA
} y6ECdVF
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publicint getStartIndex(){ prC;L*~8
return startIndex; %q/62f7?
} V/%>4GYnC
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publicvoid setStartIndex(int startIndex){ ,0~^>K
if(totalCount <= 0) G"-?&)M#a
this.startIndex = 0; (7mAt3n
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elseif(startIndex >= totalCount) (|[2J3ZET
this.startIndex = indexes %824Cqdc
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[indexes.length - 1]; B8nf,dj?X
elseif(startIndex < 0) 4^p5&5F
this.startIndex = 0; JmF l|n/H
else{ iQ tNAj
this.startIndex = indexes dT`D:)*:
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[startIndex / pageSize]; |jQ:~2U|
} =}lh_
} 8ZM?)#`@{
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publicint getNextIndex(){ WQ~;;.v#
int nextIndex = getStartIndex() + <Y*+|T+&d
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pageSize; Upc+Ukw
if(nextIndex >= totalCount) j>*R]mr6
return getStartIndex(); wg7V-+@i
else zcel|oz)
return nextIndex; @GBxL*e
} u8gS<\
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publicint getPreviousIndex(){ bV(Y`g
int previousIndex = getStartIndex() - ujDd1Bxf?
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pageSize; T_i:}ul
if(previousIndex < 0) $*SW8'],`
return0; AJf4_+He
else whmdcVh.
return previousIndex; Vr )<\h
} b=g8eMm
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} d:ARf
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抽象业务类 M}`B{]lLz
java代码: bt"W(m&f
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/** qOe+ZAJ{%N
* Created on 2005-7-12 H;?{BV
*/ '{a/2
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package com.javaeye.common.business; j.C`U(n}`
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import java.io.Serializable; {E
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import java.util.List; 7R`M,u~f2^
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import org.hibernate.Criteria; t0/p]=+.p/
import org.hibernate.HibernateException; W}--p fG
import org.hibernate.Session; '= _/ 1F*q
import org.hibernate.criterion.DetachedCriteria; *}]Nf
import org.hibernate.criterion.Projections; jq-p;-i
import DQNnNsP:M-
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org.springframework.orm.hibernate3.HibernateCallback; ?{\nf7Y
import ^$%S &W
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org.springframework.orm.hibernate3.support.HibernateDaoS 8I-u2Y$Sr
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upport; :j5n7s?&=y
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import com.javaeye.common.util.PaginationSupport; ST2.:v;lb
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public abstract class AbstractManager extends 6FUw"|\u{
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HibernateDaoSupport { ~Fe${2
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privateboolean cacheQueries = false; +1Vjw'P
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privateString queryCacheRegion; *meZ8DV2DH
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publicvoid setCacheQueries(boolean wmk
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cacheQueries){ N/]o4o
this.cacheQueries = cacheQueries; ;KOLNi-B&
} RSr
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publicvoid setQueryCacheRegion(String @|Fg,N<Y]
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queryCacheRegion){ f_wvZ&
this.queryCacheRegion = a#^B2
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queryCacheRegion; * 1T&
} ;>506jZ
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publicvoid save(finalObject entity){ e`@ # *}A
getHibernateTemplate().save(entity); T:t]"d}}
} 4FEk5D
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publicvoid persist(finalObject entity){ 7q?9Tj3
getHibernateTemplate().save(entity); F|F]970
} AcS|c:3MUy
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publicvoid update(finalObject entity){ 3Dg,GaRk
getHibernateTemplate().update(entity); WzAb|&?
} JCz@s~f\y
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publicvoid delete(finalObject entity){ .EpV;xq}
getHibernateTemplate().delete(entity); P#pn*L*"T
} E>&n.%
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publicObject load(finalClass entity, 7x#Ckep:I
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finalSerializable id){ 4Yxo~ m(
return getHibernateTemplate().load ML:Q5 ^`
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(entity, id); W [Of|?
} /rg*p
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publicObject get(finalClass entity, zBo1P(kek
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finalSerializable id){ q:l>O5
return getHibernateTemplate().get t/ +=|*
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(entity, id); 7P"| J\
} c#a@n 4
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publicList findAll(finalClass entity){ H:!7:
return getHibernateTemplate().find("from >G);j@Q
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" + entity.getName()); S7=Bd[4
} pV.Av
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publicList findByNamedQuery(finalString >fe-d#!{
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namedQuery){ Fp@TCPe#
return getHibernateTemplate 6^uq?
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().findByNamedQuery(namedQuery); eyefW n&
} NZ;{t\
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publicList findByNamedQuery(finalString query, D|@/yDQ
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finalObject parameter){ xm%Um\Pb7
return getHibernateTemplate =jlt5 z
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().findByNamedQuery(query, parameter); &Ts-a$Z7?S
} eK.e|z|
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publicList findByNamedQuery(finalString query, Xua+cVc\y
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finalObject[] parameters){ a-l;vDs
return getHibernateTemplate $"0M U
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().findByNamedQuery(query, parameters); K/A*<<r
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} 8d?g]DEN)6
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publicList find(finalString query){ ?z}=B
return getHibernateTemplate().find jZh';M8"
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(query); $wmvKQc{lx
} uIcn{RZ_z
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publicList find(finalString query, finalObject n3}!p'-CC
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parameter){ U"q/rcA
return getHibernateTemplate().find )E6;-rD0^+
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(query, parameter); (rkyW z
} O<96/a'
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public PaginationSupport findPageByCriteria T?:glp[4I
d@ Y}SWTB
(final DetachedCriteria detachedCriteria){ ]04e1F1J
return findPageByCriteria QA2borfy
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); I?"q/Ub~h
} Vl%^H[]
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public PaginationSupport findPageByCriteria la( <8
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(final DetachedCriteria detachedCriteria, finalint gN24M3{C
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startIndex){ f@8>HCI
return findPageByCriteria Vl_:c75"
a["2VY6Eq@
(detachedCriteria, PaginationSupport.PAGESIZE, &krwf
]|
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startIndex); a;QMAd!
} rA2g&
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public PaginationSupport findPageByCriteria BhM'@g*
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(final DetachedCriteria detachedCriteria, finalint g)s{IAVx
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pageSize, c7tfRq
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finalint startIndex){ p!sWYui
return(PaginationSupport) `!Ds6
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getHibernateTemplate().execute(new HibernateCallback(){ *c%oN
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publicObject doInHibernate o&`<+4
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(Session session)throws HibernateException { F#5B<I
Criteria criteria = >Y_*%QGH_
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detachedCriteria.getExecutableCriteria(session); A,\6nO67
int totalCount = ?CC"Yij
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((Integer) criteria.setProjection(Projections.rowCount %^I88,$&L
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()).uniqueResult()).intValue(); G
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criteria.setProjection 6&bY} i^K
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(null); %Eb%V ($
List items = i/~1F_
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criteria.setFirstResult(startIndex).setMaxResults 9:`(Q3Ei
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(pageSize).list(); (T!9SU
PaginationSupport ps = .C2TQ:B, .
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new PaginationSupport(items, totalCount, pageSize, iXjo[Rz^C
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startIndex); M7ers|&{
return ps; 0PU8#2pR
} UlAzJO6"
}, true); qZ}P*+`Q
} deM7fN4lTi
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public List findAllByCriteria(final " R-!(9k^`
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DetachedCriteria detachedCriteria){ TjHwjRa
return(List) getHibernateTemplate ,0E{h}(
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().execute(new HibernateCallback(){ 3}@_hS"^8
publicObject doInHibernate H^.IY_I`U*
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(Session session)throws HibernateException { <Q?a=4
Criteria criteria = yaG= j
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detachedCriteria.getExecutableCriteria(session); dbOdq
return criteria.list(); FXzFHU/dP
} :6zG7qES3
}, true); %{/%mJoX
} xdf82)
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public int getCountByCriteria(final qf=1?=l291
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DetachedCriteria detachedCriteria){ V5GW:QT
Integer count = (Integer) Tszp3,]f
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getHibernateTemplate().execute(new HibernateCallback(){ {dL?rQ>5L
publicObject doInHibernate MXzVgy
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(Session session)throws HibernateException { %H]lGN)
Criteria criteria = A |3tI
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detachedCriteria.getExecutableCriteria(session); p=C%Hmd5E
return 6_d.Yfbq
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criteria.setProjection(Projections.rowCount jS+AGE?5e
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()).uniqueResult(); d3W0-INL
} 9*E7}b,
}, true); txcf=)@>V
return count.intValue(); g8w2Vz2/
} ?V}j`r8|\4
} _UT$,0u_i
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用户在web层构造查询条件detachedCriteria,和可选的 Pt&(npjN,
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 o99pHW(E
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PaginationSupport的实例ps。 #7ov#_2Jd
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ps.getItems()得到已分页好的结果集 ^{xeij/
ps.getIndexes()得到分页索引的数组 .[Ap=UYI>
ps.getTotalCount()得到总结果数 +=]!P#
ps.getStartIndex()当前分页索引 M)+$wp
ps.getNextIndex()下一页索引 Ndo a4L)$
ps.getPreviousIndex()上一页索引 hUD7_arKF
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 2-"0 ^n{
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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 Iw<j T|y)
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一下代码重构了。 N? 5x9duK
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我把原本我的做法也提供出来供大家讨论吧: Q 2A7mGN
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首先,为了实现分页查询,我封装了一个Page类: N<QjdD&
java代码: DhX#E&
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/*Created on 2005-4-14*/ 52.>+GC
package org.flyware.util.page; fZxIY,
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/** fM #7 y [
* @author Joa UG'bOF4
* Wm H~m k"
*/ F q!fWl
publicclass Page { y!5$/`AF
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/** imply if the page has previous page */ kPQtQh]y%
privateboolean hasPrePage; }U
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/** imply if the page has next page */ Oky**B[D'
privateboolean hasNextPage; FSRm|
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/** the number of every page */ `;YU.*
privateint everyPage; (ZL sB{r^
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/** the total page number */ a6:x"Tv
privateint totalPage; 7@6g<"I
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/** the number of current page */ >XOiu#kC
privateint currentPage; U|HB=BP
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/** the begin index of the records by the current ~V/?H!r'{}
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query */ (_4;') 9
privateint beginIndex; H"Klj_<dH0
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/** The default constructor */ .))v0
public Page(){ +525{Tj
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} hLDA]s
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/** construct the page by everyPage >HPdzLY?
* @param everyPage /)xlJUq
* */ QZX~T|Ckv
public Page(int everyPage){ N$xtHtz8"
this.everyPage = everyPage; Cda!Mk:
} \uME+NF
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/** The whole constructor */ vA)O{W\o
public Page(boolean hasPrePage, boolean hasNextPage, q~L^au8
s/:Fwr4q#a
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int everyPage, int totalPage, @$"L:1_
int currentPage, int beginIndex){ )HD`O~M>
this.hasPrePage = hasPrePage; `:O\dN>ON
this.hasNextPage = hasNextPage; J(#mtj>v_
this.everyPage = everyPage; @\w,otT
this.totalPage = totalPage; n6(i`{i
this.currentPage = currentPage;
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this.beginIndex = beginIndex; M(d6Z2ibh
} (~)%Fo9X"
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/** c9j*n;Q
* @return z4@k$
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* Returns the beginIndex. 9'x)M?{8
*/ {k5X*W
publicint getBeginIndex(){ f'q 28lVf
return beginIndex; rdnRBFt
} CSV;+,Vv
+,50qN:%[
/** {B*W\[ns
* @param beginIndex 0F#>CmD
* The beginIndex to set. 4f~["[*ea
*/ F?m?UQS'u
publicvoid setBeginIndex(int beginIndex){ zq1mmFIO
this.beginIndex = beginIndex; hh~n#7w~IR
} FuX 8v
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/** ~|wos-nM
* @return i)Lp7m z
* Returns the currentPage. [!^-J}^g~\
*/ V@d)?T
publicint getCurrentPage(){ T\VNqs@
return currentPage; x90jw$\%7
} *?yJkJ"
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/** yMLOUUWa8x
* @param currentPage 'SLE;_TD
* The currentPage to set. o5\b'hR*#
*/ Aa?I8sbc
publicvoid setCurrentPage(int currentPage){
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this.currentPage = currentPage; )'Wb&A'
} M}DH5H"s
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/** 0aR,H[r[?
* @return JK#vkCkyM
* Returns the everyPage. Ufo>|A6;$
*/ 5FC4@Ms`
publicint getEveryPage(){ qQ7w&9r.M
return everyPage; 1\dn1Hh
} 4gdY`}8b^}
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/** k:A|'NK~
* @param everyPage I\\QS.2
* The everyPage to set. FVF-:C
*/ 8*g ^o\M
publicvoid setEveryPage(int everyPage){ t ]c{c#N/
this.everyPage = everyPage; Io2mWvu?5
} E?PGu!&u
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/** ql5x2n
* @return OMihXt[
* Returns the hasNextPage. Uz%Z&K
*/ $R8w+ Id
publicboolean getHasNextPage(){ ^TXf sQs
return hasNextPage; o@lWBfB*%e
} DhI>p0* T
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/** <Wl(9$
* @param hasNextPage ,/&Zw01dGN
* The hasNextPage to set. }tST)=M`
*/ ^T4Ay=~{
publicvoid setHasNextPage(boolean hasNextPage){ 2
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this.hasNextPage = hasNextPage; h5|.Et
} 2aNT#J"_
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/** Jx-wO/
* @return FM^9}*
* Returns the hasPrePage. <c,~aq#W'
*/
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publicboolean getHasPrePage(){ (L6Cy%KgV
return hasPrePage; y[0`hSQ)~
} j<tq1?? [b
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/** !- ~X?s~L
* @param hasPrePage \tJFAc
* The hasPrePage to set. ;n#%G^!H
*/ Aj"7q
publicvoid setHasPrePage(boolean hasPrePage){ $%c{06Oq(
this.hasPrePage = hasPrePage; ,<ya@Fi{
} h.
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/** FQeYx-7
* @return Returns the totalPage. XOb}<y)r~
* /jD-\,:L}
*/ E\)eu1Hw4B
publicint getTotalPage(){ Mxz,wfaH>
return totalPage; L x|',6S
} d-!<C7O}
8zQfY^/{M
/** !ZtSbOC '
* @param totalPage V*jsq[q=
* The totalPage to set. h.tY 'F
*/ Q]JX`HgPaU
publicvoid setTotalPage(int totalPage){ &hZwZgV+3
this.totalPage = totalPage; B(HT.%r^A
} <"&'>?8j
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} oJ;rc{n-
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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 KI&:9j+M)
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个PageUtil,负责对Page对象进行构造: CyM}Hc&w
java代码: Ya4?{2h@+
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/*Created on 2005-4-14*/ ~I_owCVZ
package org.flyware.util.page; 8<PKKDgbfd
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import org.apache.commons.logging.Log; k&s; {|!
import org.apache.commons.logging.LogFactory; XQ;I,\m
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/** <O857j
* @author Joa `6w#8}
* (6xDu.u?A
*/ [e"RTTRfZ
publicclass PageUtil {
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z-u?s`k**
privatestaticfinal Log logger = LogFactory.getLog *{/@uO
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(PageUtil.class); ]A:( L9
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/** m/${8
* Use the origin page to create a new page 6}&^=^-
* @param page i2F(GH?p[
* @param totalRecords aw$Y`6,S
* @return xks?y.wA
*/ zNtq"T [
publicstatic Page createPage(Page page, int Lx+`<<_dJ
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totalRecords){ W,N L*($^
return createPage(page.getEveryPage(), E/O5e(h
E 5kF^P
page.getCurrentPage(), totalRecords); P W[6/7
} ju{%'D!d9
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/**
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* the basic page utils not including exception W);W.:F
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handler eqFvrESN~=
* @param everyPage ePA;:8)_j
* @param currentPage G(OFr2M
* @param totalRecords z\Ui8jo:;
* @return page c f*zejbw
*/ H-&3}
publicstatic Page createPage(int everyPage, int zl)&U=4l
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currentPage, int totalRecords){ sv=^k(d3
everyPage = getEveryPage(everyPage); WN0c%kz=
currentPage = getCurrentPage(currentPage); ;QPy:x3
int beginIndex = getBeginIndex(everyPage, nPf'ee
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currentPage); ^
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int totalPage = getTotalPage(everyPage, ?`. XK}
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totalRecords); VD;j[~/Z
boolean hasNextPage = hasNextPage(currentPage, #]zhZW4
W8*
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totalPage); P6HGs?
*
boolean hasPrePage = hasPrePage(currentPage); "L_-}BK
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returnnew Page(hasPrePage, hasNextPage, oyQ0V94j
everyPage, totalPage, Ruj.J,
currentPage, uC[d% v`
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beginIndex); 3]S`|#J
} l\aUresm
d pn3 (
privatestaticint getEveryPage(int everyPage){ .eTk=i[N-
return everyPage == 0 ? 10 : everyPage; okDJ(AIV+
} wP`sXPSmIu
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privatestaticint getCurrentPage(int currentPage){ PW^ 8;[\QP
return currentPage == 0 ? 1 : currentPage; Z3`2-r_=
} }xJR.]).KW
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privatestaticint getBeginIndex(int everyPage, int o*;2mFP
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currentPage){ =c]a
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return(currentPage - 1) * everyPage; H5p5S\g-)
} QK7e|M
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privatestaticint getTotalPage(int everyPage, int @YB85p"]J.
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totalRecords){ ,RN|d0dE
int totalPage = 0; ^H'kHl'F
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if(totalRecords % everyPage == 0) u\w 2S4c
totalPage = totalRecords / everyPage; J!<#Nc
else "OJr*B
totalPage = totalRecords / everyPage + 1 ; =M7PvH'"
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return totalPage; #^;s<YZ`
} MLeX;He
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privatestaticboolean hasPrePage(int currentPage){ {g@A>
return currentPage == 1 ? false : true; C2.W[T
} jMqx
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privatestaticboolean hasNextPage(int currentPage, *I/A,#4r
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int totalPage){ /.)2d8,
return currentPage == totalPage || totalPage == )-)pYRlO
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0 ? false : true; ' 3VqkQ4
} PC0HH
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} <vLdBfw&N
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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。 } bCK
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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 ex=)H%_|
QA! #s\
做法如下: ~}9Bn)@
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 c-`37. J
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的信息,和一个结果集List: h-,?a_
java代码: *@~`d*d
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/*Created on 2005-6-13*/ _r[r8MB
package com.adt.bo; ;9vIa7L&
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import java.util.List; k_BSY=$e*D
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import org.flyware.util.page.Page; q>P[n z%
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/** -Sp/fjlq/
* @author Joa !6{Jq]
*/ j7,13,t1-
publicclass Result { '#KA+?@
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private Page page; ,Q+\h>I
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