Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 @^$Xy<x
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .^S#h
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 JYB<};,
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 6 ztM(2[
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分页支持类:
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java代码: n^;:V8k
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package com.javaeye.common.util; (:>:tcE
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import java.util.List; E,nC}f
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publicclass PaginationSupport { :*"0o{
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publicfinalstaticint PAGESIZE = 30; nJ`JF5tI
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privateint pageSize = PAGESIZE; 8qfg=mu+%
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privateList items; MeqW/!72$L
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privateint totalCount; 6Uk[_)1
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privateint[] indexes = newint[0]; f#a ~av9rC
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privateint startIndex = 0; 1Ig@gdmz
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public PaginationSupport(List items, int "|S \J5-%
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totalCount){ ; 9pOtr
setPageSize(PAGESIZE); ~B%=g)w
setTotalCount(totalCount); VrA9}"1x~*
setItems(items); \ qc8;"@
setStartIndex(0); 33_YZOy^j
} 6<+R55
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public PaginationSupport(List items, int gd6We)&
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totalCount, int startIndex){ sY=fS2b#)
setPageSize(PAGESIZE); QW.VAF\6*
setTotalCount(totalCount); =~% B}T
setItems(items); 7CzZHkTg
setStartIndex(startIndex); h5G>FPM-=
} xQa[bvW
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public PaginationSupport(List items, int Cyxt EzPp
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totalCount, int pageSize, int startIndex){ cy)gN
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setPageSize(pageSize); 93yJAao9
setTotalCount(totalCount); +.Kmpw4
setItems(items); q79)nhC F
setStartIndex(startIndex); Z<Rz}8s
} xQC.ap
ysfR@ sH7
publicList getItems(){ <D4.kM
return items; ?w1_.m|8u
} m&DDz+g
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publicvoid setItems(List items){ Ud0%O
this.items = items;
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} >A|6kzC
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publicint getPageSize(){ %b2.JGBqJ
return pageSize; SI3ek9|XU
} .!Kdi| a)
h[%`'(
publicvoid setPageSize(int pageSize){ *usfJ-
this.pageSize = pageSize; P@:#NU[
} +I#5?
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publicint getTotalCount(){ 2 As 4}
return totalCount; W|3XD-v@
} J4h7]
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publicvoid setTotalCount(int totalCount){ .
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if(totalCount > 0){ HH3WZ^0>
this.totalCount = totalCount; B2%)G$B
int count = totalCount / dRyK'Xr
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pageSize; u4NMJnX
if(totalCount % pageSize > 0) PIn' tV
count++; A5tY4?|
indexes = newint[count]; n8Jx;j
for(int i = 0; i < count; i++){ bp:WN
indexes = pageSize * FGBPhH% (8
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i; V^=z\wBZ
} U?d1
}else{ za'Eom-<u
this.totalCount = 0; 7rc^-!k
} D{h1"q
} dC_L~ }=
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publicint[] getIndexes(){ Rk56H
return indexes; f.rz2)o
} _wKFT>
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publicvoid setIndexes(int[] indexes){ g1L$+xD^
this.indexes = indexes;
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} tt,MO)8VD
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publicint getStartIndex(){ fQlR;4QX]
return startIndex; RG[3LX/
} ~d ~$fR
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publicvoid setStartIndex(int startIndex){ m>$+sMZE
if(totalCount <= 0) dl@
this.startIndex = 0; 3k5OYUk
elseif(startIndex >= totalCount) "8J$7g@n@
this.startIndex = indexes
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[indexes.length - 1]; afv?z
elseif(startIndex < 0) q i}HJkOq
this.startIndex = 0; R{5Qb?&wOp
else{ Miqu
this.startIndex = indexes -<sn+-uE:
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[startIndex / pageSize]; AYd7qx:~
} 0tm%Kd
} :S0r)CNP
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publicint getNextIndex(){ 6 DD^h:*>
int nextIndex = getStartIndex() + 2BBGJE
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pageSize; *Eu
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if(nextIndex >= totalCount) ,<%Y.x%4z[
return getStartIndex(); `#A&v
else W *0XV
return nextIndex; `UMv#-Y8
} g4&zBn
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publicint getPreviousIndex(){ Am%zEt$c
int previousIndex = getStartIndex() - ~d^+yR-
BHOxwW{
pageSize; YQ
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if(previousIndex < 0) ;#P@(ZVT
return0; "X g@X5BG
else NQ !t `
return previousIndex; ;#I(ucB<
} -RVwPY
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} .6+j&{WNo!
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抽象业务类 U")~bU
java代码: N?U;G*G
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/** PQ<""_S||
* Created on 2005-7-12 jn>3(GRGC$
*/ E< "aUnI
package com.javaeye.common.business; k'&BAC.K,
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import java.io.Serializable; t8\F7F P
import java.util.List; +'2Mj|d@p
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import org.hibernate.Criteria; @zB {Ig
import org.hibernate.HibernateException; *4Y1((1k
import org.hibernate.Session; Dr$k6kZ}'U
import org.hibernate.criterion.DetachedCriteria; uDay||7^g
import org.hibernate.criterion.Projections; 28C/^4
import 6E{HNPMb>
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org.springframework.orm.hibernate3.HibernateCallback; iKN~fGRc
import Mi,yg=V
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org.springframework.orm.hibernate3.support.HibernateDaoS 2aX|E4F
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upport; OGh9^,v
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import com.javaeye.common.util.PaginationSupport; W~aVwO'(
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public abstract class AbstractManager extends w<<>XIL
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HibernateDaoSupport { I!dA{INN
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privateboolean cacheQueries = false; GL_YT.(!
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privateString queryCacheRegion; UX;?~X
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publicvoid setCacheQueries(boolean Xa=oryDt
tq H7M0Ry
cacheQueries){ 8{#WF#
this.cacheQueries = cacheQueries; NE,2jeZQ .
} <iuESeDG
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publicvoid setQueryCacheRegion(String vP`Sz}FU
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queryCacheRegion){ aTuD|s
this.queryCacheRegion = e)
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queryCacheRegion; u\ro9l
} G|Rsj{2'
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publicvoid save(finalObject entity){ ^[,Q2MHCT(
getHibernateTemplate().save(entity); g(B &A
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} M(KsLu1
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publicvoid persist(finalObject entity){ =,$*-<p=3
getHibernateTemplate().save(entity); R8I%Cyc
} f_Ma~'3
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publicvoid update(finalObject entity){ V
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getHibernateTemplate().update(entity); :m]~o3KRy
} <k!M+}a 9V
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publicvoid delete(finalObject entity){ 2-728
getHibernateTemplate().delete(entity); W@`2+}
} {^=T&aCYdS
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publicObject load(finalClass entity, aUa.!,_dh
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finalSerializable id){ $nF|n+m
return getHibernateTemplate().load .A<G$ db
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(entity, id); Z8E-(@`q5Q
} EudX^L5U<d
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publicObject get(finalClass entity, r*HbglB
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finalSerializable id){ M<^]Ywq*p
return getHibernateTemplate().get 7aRtw:PQn
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(entity, id); V
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} fI"sdzu^
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publicList findAll(finalClass entity){ <}t~^E,
return getHibernateTemplate().find("from O42`Z9oK
">cLPXX
" + entity.getName()); H
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} w^z5O6
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publicList findByNamedQuery(finalString 3.+TM]RYN
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namedQuery){ U{i xok
return getHibernateTemplate IR;l{q&`
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().findByNamedQuery(namedQuery); q\s"B.(G"
} NIgqdEu1
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publicList findByNamedQuery(finalString query, DmU,}]#:
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finalObject parameter){ */c4b:s
return getHibernateTemplate |y9(qcKn$
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().findByNamedQuery(query, parameter); $`j%z@[g
} ,1/O2aQ%\0
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publicList findByNamedQuery(finalString query, oC
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} I>6 8dS[
finalObject[] parameters){ !C\$=\$
return getHibernateTemplate TOapq9B]
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().findByNamedQuery(query, parameters); 6&|hpp#[
} Y`F) UwKK
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publicList find(finalString query){ QO2@K1Y
return getHibernateTemplate().find ,ZGU\t
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(query); A0hKzj
} YTpiOPf
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publicList find(finalString query, finalObject 8tfM,.]_i
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parameter){ n(I,pF
return getHibernateTemplate().find "DaE(S&
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(query, parameter); 1lo.X_
} Q$+6f,m#W
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public PaginationSupport findPageByCriteria 8\WV.+
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(final DetachedCriteria detachedCriteria){ mtU{d^B
return findPageByCriteria {zX]41T
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); nQGl]2
} Ft
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public PaginationSupport findPageByCriteria '9{`Czc(Gb
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(final DetachedCriteria detachedCriteria, finalint /!Ay12lKE}
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startIndex){ K|pg'VT"
return findPageByCriteria [ Y+Ta,
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(detachedCriteria, PaginationSupport.PAGESIZE, Su/8P[q_
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startIndex); 6VUs:iO1j5
} KH$|wv
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public PaginationSupport findPageByCriteria JBhM*-t(M1
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(final DetachedCriteria detachedCriteria, finalint vtq$@#?~ b
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pageSize, kEgpF{"%n
finalint startIndex){ clG@]<a`_
return(PaginationSupport) 7|5X> yt
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getHibernateTemplate().execute(new HibernateCallback(){ nw4I<Q
publicObject doInHibernate <%o9*)F
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(Session session)throws HibernateException { K| dI'TnW
Criteria criteria = H*j!_>W
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detachedCriteria.getExecutableCriteria(session); <Y]e
int totalCount = "uli~ {IU
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((Integer) criteria.setProjection(Projections.rowCount =cpUc]~
},n?
()).uniqueResult()).intValue(); Xh}S_/9}5
criteria.setProjection lZAXDxhnT
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(null); /#WvC;B
List items = V7b;qC'
]_BH"ng}
criteria.setFirstResult(startIndex).setMaxResults Q,K$)bM
({ O~O5k
(pageSize).list(); O8OAXRt/Y
PaginationSupport ps = (xfh 9=.
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new PaginationSupport(items, totalCount, pageSize, NbC2N)L4
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startIndex); @XJ#oxM^
return ps; C}#$wge
} ~NZL~p
}, true); ;j.-6#n
} F\, vIS
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public List findAllByCriteria(final z&cM8w:
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DetachedCriteria detachedCriteria){ k#bG&BF
return(List) getHibernateTemplate FDFwx|
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().execute(new HibernateCallback(){ MuJP.]5>`
publicObject doInHibernate %s497'
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(Session session)throws HibernateException { ;4U"y8PVTh
Criteria criteria = l?QA;9_R'
X% )~i[_DV
detachedCriteria.getExecutableCriteria(session); 8>@JW]
return criteria.list(); jST4O"DjM
} #dKy{Q3he
}, true); Vm8@LA
} eF]8Ar1
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public int getCountByCriteria(final
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DetachedCriteria detachedCriteria){ 06O_!"GD}
Integer count = (Integer) >23$_'2
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getHibernateTemplate().execute(new HibernateCallback(){ )Gavjj&uJ
publicObject doInHibernate DuNindo8
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(Session session)throws HibernateException { d<+hQ\BF,
Criteria criteria = w
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detachedCriteria.getExecutableCriteria(session); obE8iG@H
return }zks@7kf
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criteria.setProjection(Projections.rowCount |_+#&x
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()).uniqueResult(); OLPY<ax
} $[}EV(#y
}, true); PW|=IPS
return count.intValue(); k_{?{:X;y
} JO`r)_
} J$sBfOD
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用户在web层构造查询条件detachedCriteria,和可选的 (8aj`> y
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 4d%0a%Z
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PaginationSupport的实例ps。 ,cL;,YN
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ps.getItems()得到已分页好的结果集 h}!9?:E
ps.getIndexes()得到分页索引的数组 x&*f5Y9hCi
ps.getTotalCount()得到总结果数 =w}JAEE|(i
ps.getStartIndex()当前分页索引 g0bYO!gCr
ps.getNextIndex()下一页索引 z~X/.>
ps.getPreviousIndex()上一页索引 ymyzbE
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 'prHXzi(h
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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 ]VxC]a2
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一下代码重构了。 z4:<?K
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我把原本我的做法也提供出来供大家讨论吧: (T0MWp 0
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首先,为了实现分页查询,我封装了一个Page类: /ZD 6pF
java代码: =$Mf:F@
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/*Created on 2005-4-14*/ *Q^z4UY
package org.flyware.util.page; ) jH`lY) 1
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/** k`Ifl)
* @author Joa -1Dq_!i
* pd#Sn+&rf
*/
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publicclass Page { g&c ~grD
{='Bd6_=
/** imply if the page has previous page */ eFG(2OVg}M
privateboolean hasPrePage; e~'lWJD
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/** imply if the page has next page */ \$ipnQv
privateboolean hasNextPage; t$z[ja=
^\AeX-q2v'
/** the number of every page */ #'q7 x
privateint everyPage; Inv`C,$7Q#
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/** the total page number */ m<hP"j
privateint totalPage; E{&MmrlL,
.a]#AFX
/** the number of current page */ -1,0hmn=+
privateint currentPage; /V:9*C
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/** the begin index of the records by the current ?}Z t&(#
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query */ Q0Ft.b
privateint beginIndex; LXK!4(xa W
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/** The default constructor */ d(o=)!p
public Page(){ A}SGw.3
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} ve
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/** construct the page by everyPage 0SQr%:zG
* @param everyPage >Ua'*
* */ ^sD
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public Page(int everyPage){ Mg.%&vH\
this.everyPage = everyPage; Ctz#9[|
} B={_}f
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/** The whole constructor */ tO8\} u4c
public Page(boolean hasPrePage, boolean hasNextPage, *z?Uh$I4
3$nK
o,`"*][wd
int everyPage, int totalPage, z~pp7
int currentPage, int beginIndex){ V_gl#e#
this.hasPrePage = hasPrePage; b<00 %Z
this.hasNextPage = hasNextPage; Bzrnmz5S
this.everyPage = everyPage; :J`@@H
this.totalPage = totalPage; Wr%ov6:
this.currentPage = currentPage; f\<r1
this.beginIndex = beginIndex; RJ{$`d
} ixu*@{<Z(
y|}~"^+T
/** !k)6r6
* @return yov~'S9
* Returns the beginIndex. ^
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*/ F'Y ad
publicint getBeginIndex(){ cRVL1ne
return beginIndex; . ,^WCyvq
} y4Jc|)
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/** IC0L&;En
* @param beginIndex dT|f<E/P
* The beginIndex to set. CaJ-oy8
*/ Ai<
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publicvoid setBeginIndex(int beginIndex){ |6*Bu1
this.beginIndex = beginIndex; Tu#;Y."T
} X
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= ^NvUrK
/** bV8+Eu
* @return B`B=bn+4
* Returns the currentPage. XMuZ}u[U
*/ eBrNhE-[G]
publicint getCurrentPage(){ D*%am|QL
return currentPage; eWcqf/4?"
} [CI&4) #
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/** Sf*)Z3f
* @param currentPage ]nhh|q9r{
* The currentPage to set. NUFz'MPv
*/ dH^6K0J
publicvoid setCurrentPage(int currentPage){ by@KdQow
this.currentPage = currentPage; ST*h{:u&A
} );gY8UL^
}csA|cC
/** S/'0czDMW
* @return a;HAuy`M x
* Returns the everyPage. E5&Z={
*/ 7Jf~Bn
publicint getEveryPage(){ j,M$l mR')
return everyPage; *): |WDR
} |h]V9=
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/** ZRagM'K
* @param everyPage
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* The everyPage to set. pLB2! +
*/ UCLM*`M
publicvoid setEveryPage(int everyPage){ 1INX#qTZ
this.everyPage = everyPage; z'q~%1t
} Zhq_ pus"a
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/**
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* @return X.fVbePxUU
* Returns the hasNextPage. 4XN
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*/ PftK>,+,
publicboolean getHasNextPage(){ -+*h'zZ[<w
return hasNextPage; F^yW3|Sb
} l_^OdQ9D
=0)|psCsM
/** mTE(JZt
* @param hasNextPage (C!p2f
* The hasNextPage to set. V?u#WJy/
*/ d &#_t@%
publicvoid setHasNextPage(boolean hasNextPage){ v~nKO?{
this.hasNextPage = hasNextPage; E\[B E<y
} 3oCI1>k
o1.~g'!^
/** 4D?h}U /
* @return g3tE.!a5-
* Returns the hasPrePage. w]wZJ/U`
*/ {"ST
hTZ
publicboolean getHasPrePage(){ )eyzHB,H
return hasPrePage; yLa@27T\A
} Y
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/** &6x(%o|
* @param hasPrePage 5)#j }`6
* The hasPrePage to set. pR
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*/ o:d7IL
publicvoid setHasPrePage(boolean hasPrePage){ ppAbG,7
this.hasPrePage = hasPrePage; 0?7yM:!l
} PIri|ZS
V\L;EHtc$
/** is<:}z
* @return Returns the totalPage. .vu7$~7
* \o>-L\`O
*/ C]ss'
publicint getTotalPage(){ b"I#\;Ym
return totalPage; 2 2v"?*
} V! Wy[u
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/** Tv ``\<
* @param totalPage !nBbt?*
* The totalPage to set. c!Hz'W
*/ Bz]tKJ
publicvoid setTotalPage(int totalPage){ )4g_S?l=
this.totalPage = totalPage; ^j<v~GTx+
} fd)8lK[KJ"
R]"Zv'M(AM
} qed_ PsI
7
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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 ;8]HCC@:
s%jBIeh
个PageUtil,负责对Page对象进行构造: EG{+Sz
java代码: n`5Nf
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/*Created on 2005-4-14*/ AzU:Dxr>.G
package org.flyware.util.page; j\uZo.Ot+
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import org.apache.commons.logging.Log; L ]')=J+
import org.apache.commons.logging.LogFactory; KXPCkNIN!
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/** [c?0Q3F
* @author Joa ;As~TGiT
* \RDN_Z
*/ u3h(EAH>
publicclass PageUtil { g0,~|.
, cxqr3
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privatestaticfinal Log logger = LogFactory.getLog $[T~<I
$JFjR@j
(PageUtil.class); 2Io|?
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/** (TeH)j!
* Use the origin page to create a new page (PpY*jKR
* @param page x?Sx cQP
* @param totalRecords SgU@`Pb
* @return +Y?Tr i
*/ -h8mJ D%Oi
publicstatic Page createPage(Page page, int ^*P?gG
eXl?f_9
totalRecords){ @fd<
return createPage(page.getEveryPage(), cj>@Jx}]M
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page.getCurrentPage(), totalRecords); h[(YH ;Y
} ^A ]4
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/** O@$>'Z
* the basic page utils not including exception 2-F7tcya|
xU\!UVQ/
handler Ec7xwPk
* @param everyPage A+/Lt>+AS
* @param currentPage Q4mtfpiDx
* @param totalRecords "5JMk
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* @return page %`~4rf"7
*/ >\JPX
publicstatic Page createPage(int everyPage, int oIrc))j,$
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currentPage, int totalRecords){ L91(|gQP
everyPage = getEveryPage(everyPage); ,88B@a
currentPage = getCurrentPage(currentPage); dz#"9i5b
int beginIndex = getBeginIndex(everyPage, oCo~,~kTR
.\bJ,of9
currentPage); dOD(<
int totalPage = getTotalPage(everyPage, wU%uO/sU9
Md6u4c
totalRecords); tN{0C/B9
boolean hasNextPage = hasNextPage(currentPage, l&H-<Z.8m
{A}T^q!m]
totalPage); <(E)M@2
boolean hasPrePage = hasPrePage(currentPage); (s'xO~p
P0UR{tK
returnnew Page(hasPrePage, hasNextPage, caEIE0H~
everyPage, totalPage, n^'d8Y(
currentPage, #o&T$D5
P.(UbF d'
beginIndex); m#h`iW
} 1XS~b-St
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privatestaticint getEveryPage(int everyPage){ 51}C`j|V3{
return everyPage == 0 ? 10 : everyPage; *42KLns
} `_ ^I 2
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privatestaticint getCurrentPage(int currentPage){ ^(Gl$GC$Mu
return currentPage == 0 ? 1 : currentPage; HtN:v
} @Hj]yb5
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privatestaticint getBeginIndex(int everyPage, int r%: :q^b3
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currentPage){ T:j41`g%s
return(currentPage - 1) * everyPage; i(A`'V8GY
} <,Gjo]z
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privatestaticint getTotalPage(int everyPage, int u9_?c
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totalRecords){ 1mV
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int totalPage = 0; X'd\b}Bm
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if(totalRecords % everyPage == 0) pTAm}
totalPage = totalRecords / everyPage; ?r;F'%N=
else K*~xy bA
totalPage = totalRecords / everyPage + 1 ; 8\il~IFyi
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return totalPage; SP0ueAa}
} ^C,rN;mX'
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privatestaticboolean hasPrePage(int currentPage){ Q8TR@0d
return currentPage == 1 ? false : true; .t^1e
} Fkv284,LM
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privatestaticboolean hasNextPage(int currentPage, +fvVora
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int totalPage){ 89[/UxM)
return currentPage == totalPage || totalPage == i{g~u<DH)Q
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0 ? false : true; k8Dk;N
} QKk7"2t|
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} :4:U\k;QwA
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 wKW.sZ!S1
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 UXa%$gwFw
B_!S\?}$
做法如下: Xk^<}Ep)c
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 "97sH_
,
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的信息,和一个结果集List: R]Fa?uQW
java代码: QIwO _[Q
USE!
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/*Created on 2005-6-13*/ eT F s9$
package com.adt.bo; H1evW
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import java.util.List; MNfc1I_#
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import org.flyware.util.page.Page; j1JdG<n
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/** 2%l(qfN9
* @author Joa SM}&
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*/ H2_6m5[&,
publicclass Result { j"0TAYmXwu
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private Page page; N,)rrBD
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private List content; ZU:c[`
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/** 2 $Z4 >!
* The default constructor R<T5lkJ\/
*/ (Q"s;g
public Result(){ 3qfQlqJ&3
super(); 7n#Mh-vq
} ipiS=
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/** CwF=@:*d
* The constructor using fields o>M&C
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* `yXHb
* @param page $nthMx$
* @param content 1
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*/ m]++
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public Result(Page page, List content){ e<{Ani0
this.page = page; 9@(V!G
this.content = content; #1>c)_H
} ?cr^.LV|h^
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/** U,9=&"e b
* @return Returns the content. Jpe\
*/ ECOzquvM
publicList getContent(){ 4!+IsT
return content; jW|M)[KJN
} oFJx8XU
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/** orF8%
* @return Returns the page. |>p?Cm
*/ q-0(
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public Page getPage(){ &ZPyZj
return page; |A
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} j|WN!!7
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/** p\|*ff0
* @param content LwCf}4u"
* The content to set. b;e*`f8T3c
*/ _K>YB>W}7
public void setContent(List content){ cr{f*U6`
this.content = content; SR'u*u!
} Y&b JKX
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/** i\P)P!
* @param page rcMSso2
* The page to set. f,Dj@?3+
*/ _$qH\>se
publicvoid setPage(Page page){ LT '2446
this.page = page; ?F%,d{^
} #.W<[KZf
} 8<g9 ~L
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2. 编写业务逻辑接口,并实现它(UserManager, Oc?]L&a