Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 7QsD"rL
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 +"?+Be
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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 V"4Z9Qg}
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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 H-kX-7C
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分页支持类: /5ZX6YkeH
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java代码: 8 t5kou]h
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package com.javaeye.common.util; bHwEd%f
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import java.util.List; kU<t~+
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publicclass PaginationSupport { T D_@0Rd
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publicfinalstaticint PAGESIZE = 30; BN_h3|)
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privateint pageSize = PAGESIZE; ix3LB!k<
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privateList items; )%7P?^>
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privateint totalCount; 4yl{:!la
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privateint[] indexes = newint[0]; "D(Lp*3hj&
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privateint startIndex = 0; @UD:zUT)F
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public PaginationSupport(List items, int Z3`EXs
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totalCount){ ]O@$}B];)
setPageSize(PAGESIZE); qLN\%}69/
setTotalCount(totalCount); &R94xh%@(
setItems(items); &|hK79D
setStartIndex(0); :?t~|7O:
} *T5;dh (
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public PaginationSupport(List items, int $]2)r[eA)
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totalCount, int startIndex){ 1+x"
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setPageSize(PAGESIZE); 7GgZ: $d
setTotalCount(totalCount); N^Re
setItems(items); '/W$9jm
setStartIndex(startIndex); g68p9#G
} )[Y B&
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public PaginationSupport(List items, int &k}f"TX2
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totalCount, int pageSize, int startIndex){ AJPvwu}D
setPageSize(pageSize); ~6 6xO9s
setTotalCount(totalCount); %Y^J''
setItems(items); oUv26t~
setStartIndex(startIndex); pCIzpEsRs
} >L7s[vKn
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publicList getItems(){ / ;]5X
return items; 8H!QekQZ]\
} rpR${%jc
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publicvoid setItems(List items){ "/W[gP[y%
this.items = items; 3N7H7(IR
} uDF;_bli)H
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publicint getPageSize(){ AU{"G
return pageSize; %Sr+D{B
} x$Dq0FX!%_
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publicvoid setPageSize(int pageSize){ hx;f/EPx
this.pageSize = pageSize; y>^a~}Zq
} G95,J/w
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publicint getTotalCount(){ ^t;z;.g
return totalCount; ks'>?Dw
} 0'QWa{dS\
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publicvoid setTotalCount(int totalCount){ CD|[PkjW
if(totalCount > 0){ T<AT&4
this.totalCount = totalCount; 4=zs&
int count = totalCount / dAo;y.3
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pageSize;
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if(totalCount % pageSize > 0) *XVwTW[a
count++; A4K.,bZ
indexes = newint[count]; {$*N1$(%
for(int i = 0; i < count; i++){ ).k DY?s
indexes = pageSize * jc}G+|`
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i; vF$i"^;tJ;
} 2-&EkF4p'
}else{ .KsR48g8
this.totalCount = 0; wj|Zn+{"nF
} Vz{+3vfra6
} ]Bw0Qq F#
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publicint[] getIndexes(){ sp9gz~Kq
return indexes; QLA.;`HIE
} i!wU8@
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publicvoid setIndexes(int[] indexes){ }pc9uvmIJ
this.indexes = indexes; APQq F/
} 6b|?@
8)i""OD@I
publicint getStartIndex(){ |{ jT+
return startIndex; sV^:u^
} VFHd2Ea(
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publicvoid setStartIndex(int startIndex){ ,Kit@`P%
if(totalCount <= 0) 8`Ya7c>
this.startIndex = 0; eim +oms
elseif(startIndex >= totalCount) G
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this.startIndex = indexes FMfpjuHk
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[indexes.length - 1]; taQE
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elseif(startIndex < 0) k4TWfl^}9
this.startIndex = 0; D:)Wr, 26
else{ I`>U#x*
this.startIndex = indexes v9$!v^U"D
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[startIndex / pageSize]; >ZA=9v
} {7o#Ve
} ab0Sx
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publicint getNextIndex(){ enoj4g7em^
int nextIndex = getStartIndex() + i;[y!U
a QH6akH
pageSize; gr=h!'m
if(nextIndex >= totalCount) %x)bZ=An
return getStartIndex(); M[uWX=
else z\YIwrq3*
return nextIndex; +^)v"@,VP
} oFY!NMq}:
ON ?Y
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publicint getPreviousIndex(){ [U\?+@E*
int previousIndex = getStartIndex() - sdu?#O+c1
}`"`VLh
pageSize; 1^iBS
if(previousIndex < 0) kc,"w\ ai
return0; ?b7\m":'
else L'e_?`!:
return previousIndex; `i7r]
} U=>S|>daR
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} p!.~hw9
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抽象业务类 DwD$T%kF
java代码: b7Y g~Lw
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/** R1jl <=
* Created on 2005-7-12 pYO =pL^Q
*/ 'CLZ7pV
package com.javaeye.common.business; qnm_#!&uHT
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import java.io.Serializable; h}b:-a
import java.util.List; 8hRcB[F~S
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import org.hibernate.Criteria; v=`yfCX-qX
import org.hibernate.HibernateException; Iv`IJQH>
import org.hibernate.Session; 8:cbr/F<
import org.hibernate.criterion.DetachedCriteria;
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import org.hibernate.criterion.Projections; \l+v,ELX=
import 6&3,fSP
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org.springframework.orm.hibernate3.HibernateCallback; V0ze7tSG[f
import 8^mE<
$KHm5*;nd
org.springframework.orm.hibernate3.support.HibernateDaoS kmB!NxF>)F
p [ O6
upport; !iXRt" )
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import com.javaeye.common.util.PaginationSupport; lU
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public abstract class AbstractManager extends -@TY8#O#-
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HibernateDaoSupport { ZbnAAbfKH
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privateboolean cacheQueries = false; +`y(S}Z
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privateString queryCacheRegion; TS<d?:
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publicvoid setCacheQueries(boolean lFBdiIw
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cacheQueries){ +X?ErQm
this.cacheQueries = cacheQueries; ju~$FNt8R
} Gvb2>ZN
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publicvoid setQueryCacheRegion(String x`CjFaE~F
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queryCacheRegion){ Hq@+m!
this.queryCacheRegion = !oLn=
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queryCacheRegion; ;m/e|_4;y
} _k84#E0
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publicvoid save(finalObject entity){ r924!zdbR
getHibernateTemplate().save(entity); %L|fTndKH
} HR>Y?B{
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publicvoid persist(finalObject entity){ fHt \KP
getHibernateTemplate().save(entity); =C %)(|
} bQ<qdGa
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publicvoid update(finalObject entity){ }\4yU=JPK
getHibernateTemplate().update(entity); AGhenDNV
} *X5)9dq
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publicvoid delete(finalObject entity){ 6F\ 6,E
getHibernateTemplate().delete(entity); V&mkS
} ]lWqV
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publicObject load(finalClass entity, I8H3*DE
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finalSerializable id){ kR]P/4r
return getHibernateTemplate().load *_V+K
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(entity, id); N:j7J
} l{By]S
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publicObject get(finalClass entity, !V|{(>+<
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finalSerializable id){ 8P I%Z6
return getHibernateTemplate().get G|i0n
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(entity, id); zAgX{$/Fg
} Z0gtliJ@
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publicList findAll(finalClass entity){ D
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return getHibernateTemplate().find("from p1N}2]e
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" + entity.getName()); *>fr'jj1$
} *^>"
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publicList findByNamedQuery(finalString y6(PG:L
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namedQuery){ E@}F^0c
return getHibernateTemplate E'iE#He
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().findByNamedQuery(namedQuery); qs4jUm
} r@G*Fx8Z
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publicList findByNamedQuery(finalString query, r$jWjb
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finalObject parameter){ WfPb7T
return getHibernateTemplate =m.Nm -g
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().findByNamedQuery(query, parameter); ;zCUx*{
} S-t#d7'B
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publicList findByNamedQuery(finalString query, O'4G'H)
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finalObject[] parameters){ )JMqC+J3*t
return getHibernateTemplate }#z1>y!#
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().findByNamedQuery(query, parameters); ==Gc%
} 4uF.kz-cg
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publicList find(finalString query){ ^ h=QpH
return getHibernateTemplate().find 2D 4,#X
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(query); SYJO3cY
} 9QQ XB-
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publicList find(finalString query, finalObject m*^)#
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parameter){ 7# AIX],
return getHibernateTemplate().find d$IROZK-D
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(query, parameter); Xhe& "rM
} Emlj,c<?j
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public PaginationSupport findPageByCriteria GRZz@bAO?$
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(final DetachedCriteria detachedCriteria){ sn"((BsO<
return findPageByCriteria Ny^ 1#R
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); c5]Xqq,
} ~${~To8$CW
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public PaginationSupport findPageByCriteria Q2
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(final DetachedCriteria detachedCriteria, finalint 4`O[U#?
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startIndex){ ?(ORk|)kU
return findPageByCriteria Zue3Z{31T
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(detachedCriteria, PaginationSupport.PAGESIZE, <Gpji5f2
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startIndex); }M4dze
} s|C[{n<_
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public PaginationSupport findPageByCriteria ,gV#x7IW
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(final DetachedCriteria detachedCriteria, finalint 0/HFLz'
M9)4ihK
pageSize, /@:X0}L
finalint startIndex){ >n7h%c
return(PaginationSupport) 0CzQel)L:
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getHibernateTemplate().execute(new HibernateCallback(){ *\ii+f-
publicObject doInHibernate I`_2Q:r
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(Session session)throws HibernateException { l";Yw]:^
Criteria criteria =
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detachedCriteria.getExecutableCriteria(session); yD"]:ts3
int totalCount = ^4=#,K
2 "&GH1
((Integer) criteria.setProjection(Projections.rowCount \,S|>CPQ
9'MGv*Ho
()).uniqueResult()).intValue(); N~/'EaO
criteria.setProjection z;JV3)E
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(null); kf@JEcKV
List items = 1PY]Q{r
)kep:-wm
criteria.setFirstResult(startIndex).setMaxResults ^ZMbJe%L
rrL.Y&DTK
(pageSize).list(); =g+}4P
PaginationSupport ps = LR=Ji7
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new PaginationSupport(items, totalCount, pageSize, UJO3Yn
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startIndex); ,Zmjw@w
return ps; )N 3^r>(e<
} TcZ.5Oe6h#
}, true); >pu4 G+M
} k4Q>J,k
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public List findAllByCriteria(final O)jD2X?
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DetachedCriteria detachedCriteria){ *}2L4]
return(List) getHibernateTemplate ]i
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().execute(new HibernateCallback(){ kZe<<iv
publicObject doInHibernate |]-Zz7N)
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(Session session)throws HibernateException { mZ71_4X#
Criteria criteria = 36.,:!%p
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detachedCriteria.getExecutableCriteria(session); WW:G(
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return criteria.list(); Avw=*ZW
} ///Lg{ie
}, true); 96w2qgc2
} MpOU>\
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public int getCountByCriteria(final $udhTI#,
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DetachedCriteria detachedCriteria){ N3"Jo uP
Integer count = (Integer) &
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getHibernateTemplate().execute(new HibernateCallback(){ qyM/p.mP
publicObject doInHibernate tWn
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(Session session)throws HibernateException { QIiy\E%
Criteria criteria = h0<PQZJ
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detachedCriteria.getExecutableCriteria(session); d,GOP_N8I
return "3^tVX%$\[
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criteria.setProjection(Projections.rowCount 6f +aGz
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()).uniqueResult(); lpG%rN!
} ^/BGOBK
}, true); ",,# q
return count.intValue(); Mj;V.Y
} H,} &=SCk
} W6<oy
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用户在web层构造查询条件detachedCriteria,和可选的 +gd5&
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 b`X''6
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PaginationSupport的实例ps。 z>W:+W"o
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ps.getItems()得到已分页好的结果集 IV,4BQ$
ps.getIndexes()得到分页索引的数组 Uxjc&o
ps.getTotalCount()得到总结果数 -leX|U}k
ps.getStartIndex()当前分页索引 Q]9$dr=Kk0
ps.getNextIndex()下一页索引 r *K
ps.getPreviousIndex()上一页索引 !JA;0[;l=
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 s#Dj>Fej
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 ZR!8hw8
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一下代码重构了。 )'kpO> _G
tLu&3<%
我把原本我的做法也提供出来供大家讨论吧: E7$&:xqx
[[|#}D:L
首先,为了实现分页查询,我封装了一个Page类: V}V->j*
java代码: 9w-\K]
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/*Created on 2005-4-14*/ ,)`_?^\$f
package org.flyware.util.page; %}@iz(*}>
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/** ?W'z5'|
* @author Joa `O6#-<>
* F;Q,cg M
*/ s!(R
publicclass Page { L3{(Bu
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/** imply if the page has previous page */ HTh?&u\QG
privateboolean hasPrePage; >W> rhxU
}r,M(Zr
/** imply if the page has next page */ h:fiUCw
privateboolean hasNextPage; [e><^R*u
9d"*Z%!j
/** the number of every page */ JX0M3|I=
privateint everyPage; ox&5}&\
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/** the total page number */ z 3aGK
privateint totalPage; 5Od%Jhtt
PIH\*2\/
/** the number of current page */ 7.29'
privateint currentPage; 7wj2-BWa
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/** the begin index of the records by the current :$D*ab^^P
ehW [LRtq
query */ r(r(&NU
privateint beginIndex; 7 z
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/** The default constructor */ b^HDN(v
public Page(){ 9\ "\7S/Z
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} `%Fp'`ZM$8
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/** construct the page by everyPage U =J5lo
* @param everyPage (m3hD)!+y
* */ ]+:yfDtZd
public Page(int everyPage){ 4.,EKw3
this.everyPage = everyPage; :-{"9cgFR
} Lip#uuuXXN
%gmx47
/** The whole constructor */ Bj7*2}
public Page(boolean hasPrePage, boolean hasNextPage, XH%pV
0~U0s3
o(ow{S@=4
int everyPage, int totalPage, s*GZOz
int currentPage, int beginIndex){ \kQ)fk]^
this.hasPrePage = hasPrePage; ]~;*9`:
this.hasNextPage = hasNextPage; LtB5;ByeQ0
this.everyPage = everyPage; _ &, A
this.totalPage = totalPage; |!(8c>]Bo
this.currentPage = currentPage; l`\L@~l n
this.beginIndex = beginIndex; d.f0OhQ
} =b%f@x_U1
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/** b%lB&}uw}
* @return HwFg;r
* Returns the beginIndex. TFkG"ev
*/ PzPNvV/o
publicint getBeginIndex(){ 437Wy+Q|e
return beginIndex; + nR("Il
} eP2Q2C8g
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/** \udB4O
* @param beginIndex P8c_GEna
* The beginIndex to set. QjLU@?&
*/ 0'd@8]|H
publicvoid setBeginIndex(int beginIndex){ Vs5 &X+k
this.beginIndex = beginIndex; [6TI_U~
} $tu
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/** Vu(NP\Wm
* @return 6 :4GI
* Returns the currentPage. ; Pk"mC
*/ DG;u_6;JR
publicint getCurrentPage(){ :kHk'.V1(
return currentPage; lH3.q4D
5
} -=lm`X<:
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/** .!~ysy
* @param currentPage a >fA-@
* The currentPage to set. .45wwouZkc
*/
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publicvoid setCurrentPage(int currentPage){ c&T5C,]
this.currentPage = currentPage; DAq
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} ai;!Q%B#Q
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/** bpsyO>lx/
* @return G5qsnTxUJ
* Returns the everyPage. Lx-%y'P
*/ :fmV||Q
publicint getEveryPage(){ MLr L"I"
return everyPage; .g/!u(iy
} VQ!4(
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/** o2(w
* @param everyPage AkW,Fp1e
* The everyPage to set. -v9 (43
*/ IG0_
publicvoid setEveryPage(int everyPage){ Y#lAG@$
this.everyPage = everyPage; X)SUFhP\
} pW ~;B*hF
87[o^) 8
/** w'}s'gGE
* @return TJNE2
* Returns the hasNextPage. ~^.,Ftkb@7
*/ {Q/@ Y.~<
publicboolean getHasNextPage(){ 08:K9zr
return hasNextPage; yHM29fEZk
} x/1FQ>n:9
cMi9 Z]
/** `T[yyOL/
* @param hasNextPage [vtDtwL
* The hasNextPage to set. ?bd!JW bg`
*/ <;i&-,
publicvoid setHasNextPage(boolean hasNextPage){ Z2{$FN
this.hasNextPage = hasNextPage; 5%S5*c6BD
} NZ`6iK-V_
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/** _`Kh8G
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* @return &h[)nD
* Returns the hasPrePage. z*nztvY@e
*/ rREev
publicboolean getHasPrePage(){ ~(m6dPm$}m
return hasPrePage; WL%T nux
} BCExhp
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/** *QW.#y>"j
* @param hasPrePage dY?l
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* The hasPrePage to set. A f?&VD4K
*/ XF{2'x_R
publicvoid setHasPrePage(boolean hasPrePage){ LzXIqj'H7T
this.hasPrePage = hasPrePage; 9F,XjPK=
} yMNOjs'c {
j+<!4 0#
/** 1slt[&4N
* @return Returns the totalPage. Y\!:/h]E&
* m$Tt y[0
*/ /XRgsF
publicint getTotalPage(){ ^umHuAAE
return totalPage; Ahd{f!
} unL1/JY z
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/** &m(eMX0lU
* @param totalPage 5NSXSR9c
* The totalPage to set. Rpcnpo
*/ 2b
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publicvoid setTotalPage(int totalPage){ EI9Yv>7 d{
this.totalPage = totalPage; \l6mXIn=>
} AO$aW yI
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} +&AU&2As
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Fo"'[`
/C<} :R
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 jP@t!=
Rx<[bohio
个PageUtil,负责对Page对象进行构造: $AFiPH9
java代码: e ]>{?Z
RmN\;G?}
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/*Created on 2005-4-14*/ )fZ5.W8UE]
package org.flyware.util.page; @7PE&3
`0ju=FP'u5
import org.apache.commons.logging.Log; BJ/#V)
import org.apache.commons.logging.LogFactory; 9.goO|~B~
DA4!-\bt@
/** `~t$k7wm=
* @author Joa Pb D|7IM
* qj|B #dU
*/ ;rta#pRn
publicclass PageUtil { A%M&{S'+|X
QQjMC'
privatestaticfinal Log logger = LogFactory.getLog 6ud<B
EVmE{XlD;
(PageUtil.class); ~w%Z Bp
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/** _jb"@TY
* Use the origin page to create a new page J2#=`|t"
* @param page 13{"sY:PT#
* @param totalRecords o9HDxS$~^
* @return Ll&5#q
*/ +ACV,GG
publicstatic Page createPage(Page page, int ;v+CQx
e;}5~dSi
totalRecords){ >Q\H1|?
return createPage(page.getEveryPage(), ELNA-ZKp
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page.getCurrentPage(), totalRecords); Zr2QeLQC(
} FkECY
B
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/** !r!Mq~X<=
* the basic page utils not including exception { K0T%.G
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handler g9"_ BG
* @param everyPage 1y8:tri>N
* @param currentPage 7#|NQ=yd
* @param totalRecords Sdt2D
* @return page &FvNz
*/ lB\j>.c
publicstatic Page createPage(int everyPage, int Y.*lO
Q}Vho.N@=
currentPage, int totalRecords){ !%M-w0vC9
everyPage = getEveryPage(everyPage); :U[_V4?7
currentPage = getCurrentPage(currentPage); E 0pF; P5
int beginIndex = getBeginIndex(everyPage, C X'E+
s9GPDfZ
currentPage); 01q7n`o#zf
int totalPage = getTotalPage(everyPage, @%cJjZ5y
"RX?"pB
totalRecords); UZX)1?U
boolean hasNextPage = hasNextPage(currentPage, Tx_(^K
Iq}h}Wd
totalPage); |~CnELF)
boolean hasPrePage = hasPrePage(currentPage); ng<`2XgU
gS|xicq!
returnnew Page(hasPrePage, hasNextPage, }EIwkz8
everyPage, totalPage, )LhO}zQ
currentPage, =<_5gR
1k%ko?
beginIndex); Yh%wf3
UEO
} *wF:Q;_<z
g4$%)0x%
privatestaticint getEveryPage(int everyPage){ Zz&i0r
return everyPage == 0 ? 10 : everyPage; &s;%(c04A
}
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privatestaticint getCurrentPage(int currentPage){ 9FLn7Y
return currentPage == 0 ? 1 : currentPage; gX _BJ6
} J+|ohA
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privatestaticint getBeginIndex(int everyPage, int 7VXeu+-P
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currentPage){ l?1!h2z%
return(currentPage - 1) * everyPage; p+7BsW.l
} !^fJAtCN]
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privatestaticint getTotalPage(int everyPage, int lqCn5|S]
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totalRecords){ rYS D-Kq
int totalPage = 0; *f#4S_ws`
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if(totalRecords % everyPage == 0) jrl6):x
totalPage = totalRecords / everyPage; @YB\PVhW
else +e:ZN
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totalPage = totalRecords / everyPage + 1 ; 2!3&Ub#FO
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return totalPage; l>(G3lIw
} `pMI[pLZe
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privatestaticboolean hasPrePage(int currentPage){ fBOPd=
return currentPage == 1 ? false : true; ge oN4
} 6qJB"_.
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privatestaticboolean hasNextPage(int currentPage,
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int totalPage){ ?^vZ{B)&0E
return currentPage == totalPage || totalPage == f,a %@WT
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0 ? false : true; y&Hh8|'mC
} ZtLn*M
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} Xh/av[Q
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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。 r?I(me,
nu<!/O
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 tp^'W7E
_D4}[`
做法如下: S%fBt?-Cm
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 z.^
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的信息,和一个结果集List: ~QcKW<bz
java代码: {@$3bQ
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8u,
j[`?`RyU
/*Created on 2005-6-13*/ -*M:OF"Zh
package com.adt.bo; P[K=']c
fNJ;{
import java.util.List; %4Zy1{yKs_
jf/9]`Hf
import org.flyware.util.page.Page; k#) .E X
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/** wcf_5T
* @author Joa ACYn87tq
*/ ;alFK*K6
publicclass Result { bVHi3=0{
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private Page page; OP}p;(
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private List content; AyO|9!F@A
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/** Ig KAD#2a
* The default constructor I}IW!K
*/ 2QRn
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public Result(){ |=T<WU1$
super(); q*nz4QTOE
} "%t`I)
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/** 8Jj0-4]
* The constructor using fields 3]es$ Jy
* ]?`p_G3O
* @param page x 4</\o
* @param content F5MPy[
*/ 9 lJj/
public Result(Page page, List content){ [B @j@&
this.page = page; ug"<\"
this.content = content; H;|:r[d!
} |uBC0f
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/** H`lD@q'S
* @return Returns the content. "@w%TcA
*/ E}9ldM=]s
publicList getContent(){ ](:FW '-
return content; c| ( ?
} =>\-ma+
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/** {taVAcb
* @return Returns the page. 8G] m7Z
*/ h)^A3;2F
public Page getPage(){ eI rmD
return page; yWi0tE{
} :qTcxzV
(<ZkmIXN
/** 1DtMY|wP
* @param content ko2j|*D6@~
* The content to set. ]=VS~azZ5
*/ .4FcZJvy
public void setContent(List content){ XuoEAu8]
this.content = content; |;m`874
} 0DVZRB
l)*,18n
/** cievC,3*
* @param page CN~NyJL H
* The page to set. 1 3`0d
*/ e)dWa'2<
publicvoid setPage(Page page){ D8AIVK]
this.page = page; !LOors za
} )z235}P
} {a8^6dm*E
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uE#,c\[8
g)?g7{&?>?
zZ"U9!T
2. 编写业务逻辑接口,并实现它(UserManager, ~uR6z//%
n,a5LR
UserManagerImpl) Evq Ai/(g
java代码: |EV\a[
!FO^:V<|5
#lsh N,CPm
/*Created on 2005-7-15*/ O& %"F8B
package com.adt.service; pNE\@U|4E
@PoFxv
import net.sf.hibernate.HibernateException; fCf#zV[
AYA&&