Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Sd},_Kh
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .K IVf8)"
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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 z[fB!O
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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 \6sqyWI
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分页支持类: 4j>fI)FUW
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java代码: >':5?\C+-
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package com.javaeye.common.util; WwuZ(>|
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import java.util.List; JqEW=5
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publicclass PaginationSupport { OifvUTl9b
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publicfinalstaticint PAGESIZE = 30; ?Gd sOg^
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privateint pageSize = PAGESIZE; k#O,j pbB
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privateList items; oid[syPB
$;2)s}ci
privateint totalCount; o(*F])d;
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privateint[] indexes = newint[0]; ,CciTXf
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privateint startIndex = 0; c<wavvfUo
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public PaginationSupport(List items, int e+'%!w"B
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totalCount){ 3HZ~.
setPageSize(PAGESIZE); J~KX|QY.S
setTotalCount(totalCount); -gS"pE^1
setItems(items); =m7H)z)i*J
setStartIndex(0); _%y4q%#
} k[\a)WcY8
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public PaginationSupport(List items, int B**Nn!}0
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totalCount, int startIndex){ DG(%-w8p"
setPageSize(PAGESIZE); 2j&v;dmh<
setTotalCount(totalCount); %r%So_^
setItems(items); .2.qR,"j
setStartIndex(startIndex); u-JpI-8h
} #)s!}X^
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public PaginationSupport(List items, int ~i ,"87$[
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totalCount, int pageSize, int startIndex){ lCJ6Ur;
setPageSize(pageSize); %@?A_jS
setTotalCount(totalCount); TVaA>]Fv
setItems(items); {$d <1y^
setStartIndex(startIndex); y6-XHeU
} X32C}4-B
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publicList getItems(){ a 7#J2 r
return items; }#1/fok
} wN97_Y=`n
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publicvoid setItems(List items){ 4zjs!AK%
this.items = items; 5G[x }4U
} LY 0]l$
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publicint getPageSize(){ Z^yNLF *&V
return pageSize; qnChM;)
} `zA#z />
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publicvoid setPageSize(int pageSize){ ,
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this.pageSize = pageSize; thc <xxRP
} _Mk7U@j+9
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publicint getTotalCount(){ [Wi1|]X"G
return totalCount; ?Q0I'RC
} KkcXNjPVS
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publicvoid setTotalCount(int totalCount){ j+rG7z){K
if(totalCount > 0){ VwyVEZt
this.totalCount = totalCount; yVX8e I
int count = totalCount / D:"{g|nW}
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pageSize; s?2$ue&-f
if(totalCount % pageSize > 0) \?**2{9&)
count++; Kcy@$uF{2
indexes = newint[count]; ;"kaF!
for(int i = 0; i < count; i++){
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indexes = pageSize * XJ1=m
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} dY(;]sxFr
}else{ H1/?+N}(
this.totalCount = 0; B07v^!Z>
} YJ_\Ns+Ow
} zmI] cD@G
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publicint[] getIndexes(){ z//VlB
return indexes; ?'s6Xmd
} +s++7<C
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publicvoid setIndexes(int[] indexes){ x79Ha,
this.indexes = indexes; ]QVNn?PA8
} :9|\Z|S(I
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publicint getStartIndex(){ gNYqAUG5
return startIndex; nKoiG*PI
} :,B7-kBw
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publicvoid setStartIndex(int startIndex){ H+E$:)gN
if(totalCount <= 0) #|[
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this.startIndex = 0; ?e[lr>-
elseif(startIndex >= totalCount) QnQOm""
this.startIndex = indexes U8.7>ENnP&
/D!;u]
[indexes.length - 1]; +{<#(}
elseif(startIndex < 0) #@HF<'H}mu
this.startIndex = 0; a2IgC25
else{ eI45PMP
this.startIndex = indexes rf~Y6U?7
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[startIndex / pageSize]; 7%f&M>/
} Xpe)PXb
} %D$]VSP;
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publicint getNextIndex(){ eET&pP3Rp
int nextIndex = getStartIndex() + AIMSX]m
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pageSize; 2c6g>?
if(nextIndex >= totalCount) #Cpd9|
return getStartIndex(); Od f[*
else 7xRl9
return nextIndex; &xRo^iV?
} Q></`QWpoB
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publicint getPreviousIndex(){ X+UJzR90
int previousIndex = getStartIndex() - *na?n2Yzt
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pageSize; V |(H|9
if(previousIndex < 0) 8J$|NYv_b
return0; 9mA{K
else .X# `k
return previousIndex; vz.>~HBP
} Po%LE]v,
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} F*"}aP$
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抽象业务类 .o) `m9/
java代码: C74a(Bk}H
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/**
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* Created on 2005-7-12 Fu!RhsW5j
*/ J8mdoVt
package com.javaeye.common.business; SkmT`*v@
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import java.io.Serializable; `BlI@6th
import java.util.List; x)( |[
ep)>X@t
import org.hibernate.Criteria; bv&;R
import org.hibernate.HibernateException; t+9][Adf
import org.hibernate.Session; v`M3eh@$A
import org.hibernate.criterion.DetachedCriteria; dKdj`wB
import org.hibernate.criterion.Projections; d_IAs
import &mb{.=
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org.springframework.orm.hibernate3.HibernateCallback; ~ 4kc/a
import #B4%|v;`E?
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org.springframework.orm.hibernate3.support.HibernateDaoS 6i1LjLB
#Y$hNQQ$F
upport; ?Y@N`S
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import com.javaeye.common.util.PaginationSupport; zux{S;:?
iyg*Xbmi~.
public abstract class AbstractManager extends %}%Qc6.H
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HibernateDaoSupport { |UX(+;n
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privateboolean cacheQueries = false; {WYX~Mvvj
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privateString queryCacheRegion; *s:(jDlv
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publicvoid setCacheQueries(boolean H '
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cacheQueries){ /pT=0=
this.cacheQueries = cacheQueries; B]Thn
} Q\ 0cvmU
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publicvoid setQueryCacheRegion(String 1,% R;7J=g
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queryCacheRegion){ INJEsz
this.queryCacheRegion = cLLbZ=`
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queryCacheRegion; `hQ5VJo
} Fvbh\m
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publicvoid save(finalObject entity){ v_DedVhe
getHibernateTemplate().save(entity); t+!$[K0/
} hpD!2 K3>
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publicvoid persist(finalObject entity){ NA ~Vg8
getHibernateTemplate().save(entity); tP$<UKtU
} R}!:'^
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publicvoid update(finalObject entity){ UWd=!h^dt
getHibernateTemplate().update(entity); ui/a|Q
} LGw$v[wb
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publicvoid delete(finalObject entity){ 7t0er'VC
getHibernateTemplate().delete(entity); :g Wu9Y|{
} 9-fLz?J
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publicObject load(finalClass entity, KV0]m^@x
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finalSerializable id){ \D*KGd]M0
return getHibernateTemplate().load Na]:_K5Dp
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(entity, id); `T5W}p[6
} ]1#e#M]#
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publicObject get(finalClass entity, ~E2KZm
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finalSerializable id){ Ng~FEl
return getHibernateTemplate().get 7%x[q}
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(entity, id); Ws|j#X<
} m8d!<
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publicList findAll(finalClass entity){ i#vYyVr[
return getHibernateTemplate().find("from EVsC >rz
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1
" + entity.getName()); Lh!J >
} VJ]JjB
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publicList findByNamedQuery(finalString T[UN@^DP(
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namedQuery){ F%@aB<Nu
return getHibernateTemplate
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().findByNamedQuery(namedQuery); i:Y^{\Z?V
} uKUiV%p!
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publicList findByNamedQuery(finalString query, O;:mCt _H
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finalObject parameter){ !Prg_6
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return getHibernateTemplate v$?+MNks
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().findByNamedQuery(query, parameter); 1WxK#c-)
} $P/~rZ@M@
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publicList findByNamedQuery(finalString query, lrlgz[
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finalObject[] parameters){ 1\
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return getHibernateTemplate Yg%I?
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().findByNamedQuery(query, parameters); ;-~B)M_S`
} tE<H|_{L
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publicList find(finalString query){ `T@i. 'X
return getHibernateTemplate().find u8&Z!p\
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(query); E7j(QOf
} SJb&m-
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publicList find(finalString query, finalObject }YGV\Nu
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parameter){ &^ 1$^=
return getHibernateTemplate().find ;K:zmH
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(query, parameter); Y!-M_v /
} 46_xyz3+
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public PaginationSupport findPageByCriteria PUT=C1,OFR
#+ 0M2Sa
(final DetachedCriteria detachedCriteria){ <J<{l
return findPageByCriteria _S<3\%(0
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ,w<S|#W~+
} e$<0
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public PaginationSupport findPageByCriteria 4tRYw0f47
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(final DetachedCriteria detachedCriteria, finalint h\fjBDU^
^ Edfv5
startIndex){ +\d56j+D
return findPageByCriteria I8hz(2jI
Aza /6OL
(detachedCriteria, PaginationSupport.PAGESIZE, dk[!V1x4\
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startIndex); 5d Eh7XL
} T*Y~\~Jhu
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public PaginationSupport findPageByCriteria PxWT1 !
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(final DetachedCriteria detachedCriteria, finalint \ub7`01
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pageSize, _<n~n]%
finalint startIndex){ ZCMw3]*
return(PaginationSupport) w1EXh
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getHibernateTemplate().execute(new HibernateCallback(){ q6McG HT
publicObject doInHibernate &N2N6&Ta/
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(Session session)throws HibernateException { (9''MlGd%
Criteria criteria = Q|S.R1L^
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detachedCriteria.getExecutableCriteria(session); PS)4 I&;U
int totalCount = pnl{&<$C%C
jwc)Lj}
((Integer) criteria.setProjection(Projections.rowCount k^3>Y%^1
[A+
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()).uniqueResult()).intValue(); orzZ{87
criteria.setProjection >,V9H$n
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(null); ?AK(|
List items = I5k$H$
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criteria.setFirstResult(startIndex).setMaxResults
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(pageSize).list(); I:R[;TB?y
PaginationSupport ps = ?ZV/U!y
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new PaginationSupport(items, totalCount, pageSize, a@_4PWzF:
~8'sBT
startIndex); -^&<Z
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return ps; Zi *2nv'
} 2%DSUv:H%
}, true); vv72x]
} x,=&JtKVc
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public List findAllByCriteria(final i?p$H0bn
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DetachedCriteria detachedCriteria){ ~8q)^vm>f?
return(List) getHibernateTemplate [+rfAW>p}
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().execute(new HibernateCallback(){ dPW#C5dm
publicObject doInHibernate wT6"U$cV
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(Session session)throws HibernateException { du<tGsy
Criteria criteria = CuaVb1r
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detachedCriteria.getExecutableCriteria(session); Mo|;'+
return criteria.list(); k0OYJ/
} Y+kfBvxyf
}, true); r<9Iof4
} j@n)kPo,1
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public int getCountByCriteria(final f}o\*|k_|
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DetachedCriteria detachedCriteria){ >~''&vdsk\
Integer count = (Integer) AHD=<7Rs
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getHibernateTemplate().execute(new HibernateCallback(){ ,82S=N5V!
publicObject doInHibernate A!od9W6
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(Session session)throws HibernateException { /K+r?
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Criteria criteria = rJ`!: f
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detachedCriteria.getExecutableCriteria(session); 1h^:[[!c
return m]'#t)B_m
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criteria.setProjection(Projections.rowCount :vmH]{R
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()).uniqueResult(); NxkGOAOE
} ..IfP@
}, true); VpE*(i$
return count.intValue(); ~8PZ5;g
} u}#(.)a:
} 1vS#K=sb
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216 RiSr*
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用户在web层构造查询条件detachedCriteria,和可选的 y%&q/tk
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 bHY=x}Hv
}fp-pe69z
PaginationSupport的实例ps。 (o 5s"b
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ps.getItems()得到已分页好的结果集 i[O& )N,c
ps.getIndexes()得到分页索引的数组 ts,ZvY]
ps.getTotalCount()得到总结果数 F8nYV
ps.getStartIndex()当前分页索引 4)S,3G
ps.getNextIndex()下一页索引 .UQzPnK
ps.getPreviousIndex()上一页索引 ;0Q4<F
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 .6ylZ
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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 3$jT*OyG#
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一下代码重构了。 +vw\y
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我把原本我的做法也提供出来供大家讨论吧: .r|tSfm6
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首先,为了实现分页查询,我封装了一个Page类: =Z{O<xw'
java代码: |T<_ 5Ik
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/*Created on 2005-4-14*/ /74QMx?
package org.flyware.util.page; ;nI] !g:
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/** S50k>_a;
* @author Joa s,"]aew
* ?so=;gh
*/ mu\6z_e
publicclass Page { ]V[q(-Jk
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/** imply if the page has previous page */ 7z%L*z8V
privateboolean hasPrePage; =%BSKSG.
a]$1D!Anc
/** imply if the page has next page */ jrCfWa}z
privateboolean hasNextPage; yjO1 Ol
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/** the number of every page */ Rm2yPuOU}A
privateint everyPage; _jvxc'6
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/** the total page number */ ;d@#XIS&-(
privateint totalPage; 'S20\hwt-
<kfnpB=
/** the number of current page */ ({ +!`}GY
privateint currentPage; %Si6]3-^@
To\QjP-
/** the begin index of the records by the current OstQqV%@
GiJ *Wp
query */ Ozw.siD
privateint beginIndex; I!ED?n
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ud63f`W]4
/** The default constructor */ JL`-0P<M
public Page(){ L,HhbTRca
`A,-@`p
} #{6{TFx\
l?\jB\,
/** construct the page by everyPage pg6cF
* @param everyPage S~<$Hy*kh
* */ aJSO4W)P
public Page(int everyPage){ cA&9e<
this.everyPage = everyPage; L s
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} Ij 79~pn
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/** The whole constructor */ -fM1nH&
public Page(boolean hasPrePage, boolean hasNextPage, b\ X@gq
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int everyPage, int totalPage, bc*X/).
int currentPage, int beginIndex){ <NHH^M\N
this.hasPrePage = hasPrePage; R$EW4]j
this.hasNextPage = hasNextPage; XP`Nf)3{Yd
this.everyPage = everyPage; 9,c(ysv"
this.totalPage = totalPage; I^* Nqqq
this.currentPage = currentPage; 0!D4pvlt
this.beginIndex = beginIndex; u6J8"<
-W
} c\/=iVw,
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/** E}%B;"b/Tj
* @return {Je[ZQ$
* Returns the beginIndex. ?)/#+[xa
*/ W= ig.-
publicint getBeginIndex(){ <'}YyU=
return beginIndex; *HU &4E\a
} #`~C)=-
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/** 2"COP>
* @param beginIndex T!uM+6|Y
* The beginIndex to set. ]yV!
*/ H
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publicvoid setBeginIndex(int beginIndex){ at @G/?
this.beginIndex = beginIndex; *$#W]bO
} <g-9T -Ky
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/** "x%Htq@
* @return nz%DM<0$
* Returns the currentPage. UJ%R
*/ SP@ >vl+;
publicint getCurrentPage(){ pD(j'[
return currentPage; Fzm*Pz3
} FOb0uj=(v
c7 ?_46J
/** -Mip,EO
* @param currentPage ,yC-+VL
* The currentPage to set. #OZ>V3k
*/ CZ8KEBl
publicvoid setCurrentPage(int currentPage){ rDl*d`He!
this.currentPage = currentPage; qjwxhabc
} /{Is0+)
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/** qjc8fP2
* @return O3;u G.:1
* Returns the everyPage. y+Ra4G#/}
*/ Yy5h"r
publicint getEveryPage(){ }~2LW" 1'
return everyPage; \1d( 9jR
} ~W*FCG#E
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/** Q[Z8ok
* @param everyPage }I2wjO
* The everyPage to set. T
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*/ oVnvO iAc
publicvoid setEveryPage(int everyPage){ 60P<4
this.everyPage = everyPage; "33Fv9C#bK
} 0Vj4+2?L5;
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/** phQUD
* @return EJj.1/]|r
* Returns the hasNextPage. 5]~'_V
*/ -M~8{buxv
publicboolean getHasNextPage(){ ,aOl_o -&
return hasNextPage; czA5n
} R$v[!A+:'
>~#yu&*D
/** B`YTl~4
* @param hasNextPage s kvGU(G}
* The hasNextPage to set. dW)B1iUo!
*/ 2$9odD<r
publicvoid setHasNextPage(boolean hasNextPage){ Ac96
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this.hasNextPage = hasNextPage; ZLc -RM
} tI]Q%S,
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/** 9"NF/)_
* @return yZ
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* Returns the hasPrePage. m];]7uB5=
*/ ,ly\Ka?zO
publicboolean getHasPrePage(){ =FlDb
5t{
return hasPrePage; Z|%_&M
} r~E=4oB7
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/** Gp1?iX?ml
* @param hasPrePage >c1!p]&V
* The hasPrePage to set. C\\~E9+
*/ z[LNf.)}
publicvoid setHasPrePage(boolean hasPrePage){ .@2m07*1
this.hasPrePage = hasPrePage; XQ#;Zs/l
} v;BV@E0}x
Ld\R:{M"
/** aL*&r~`&e'
* @return Returns the totalPage. Mh~q//
* Olt`:;j-
*/ ) dn(G@5
publicint getTotalPage(){ T m,b,hi$
return totalPage; 2-&k^Gl!:
} nx@=>E+a
YO#M/%^j
/** =w;F<M|Y
* @param totalPage :Uz| 3gq
* The totalPage to set. \O}E7-
*/ g=39C>
publicvoid setTotalPage(int totalPage){ X]'{(?Ch
this.totalPage = totalPage; b $'FvZbk
} "&%I)e^
LE&RY[
} W_||6LbZy
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 ;ZH3{
yaD~1"GA'O
个PageUtil,负责对Page对象进行构造: ,C
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java代码: <_h~w}
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/*Created on 2005-4-14*/ f) zn TJL
package org.flyware.util.page; VkvB<3
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import org.apache.commons.logging.Log; |P[w==AAf
import org.apache.commons.logging.LogFactory; ,eOB(?Ku
C+'/>=>a.
/** ~{d$!`|a
* @author Joa %Da8{%{`Pc
* Mx&&0#;r
*/ 6tB+J F
publicclass PageUtil { E;,u2[3
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privatestaticfinal Log logger = LogFactory.getLog .}&`TU
}
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(PageUtil.class); e7@ojOQ%
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/** FQm`~rA~zt
* Use the origin page to create a new page >go,K{cK6
* @param page 7"aN#;&
* @param totalRecords `2' #!-
* @return SFO({w(
*/ D'7SAFOM
publicstatic Page createPage(Page page, int E7NV ^4h
}0eF~>Df
totalRecords){ esHg'8?U
return createPage(page.getEveryPage(), 0F]>Jby
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page.getCurrentPage(), totalRecords); ?$vCW|f
} [OM7g'?S0
rv&<{@AS~
/** _hN\10ydY
* the basic page utils not including exception G.rrv
XR+Y=R
handler Kw-gojZ
* @param everyPage p qfUW+>
* @param currentPage os,* 3WO
* @param totalRecords }#.L7SIJ<J
* @return page y603$Cv
*/ kB3H="3[[
publicstatic Page createPage(int everyPage, int m4aB*6<lq
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currentPage, int totalRecords){ >{N9kWY
everyPage = getEveryPage(everyPage); Kh,V.+7k
currentPage = getCurrentPage(currentPage); J]v%q,"
int beginIndex = getBeginIndex(everyPage, aIJt0;
~5_Ad\n9
currentPage); pv*,gSS
int totalPage = getTotalPage(everyPage, 18~>ZR
(}a8"]Z
totalRecords); 9bP^`\K[N
boolean hasNextPage = hasNextPage(currentPage, q-.,nMUF
SNfr"2c'h~
totalPage); Px$/ _`H
boolean hasPrePage = hasPrePage(currentPage); ?,p;O
+,2:g}5
returnnew Page(hasPrePage, hasNextPage, plUZ"Tr
everyPage, totalPage, M\sN@+
currentPage, ]+(6,ct&.
mFg<dTx0c8
beginIndex); `!XY]PI+e
} iJ~Zkd
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privatestaticint getEveryPage(int everyPage){ G"\`r* O
return everyPage == 0 ? 10 : everyPage; I Y2)?"A
} 4xk|F'6K
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privatestaticint getCurrentPage(int currentPage){ UF?H>Y&
return currentPage == 0 ? 1 : currentPage; iTFdN}U
} )0ea+ib
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privatestaticint getBeginIndex(int everyPage, int NPCs('cd>?
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currentPage){ fF?z|
return(currentPage - 1) * everyPage; N"8_S0=pw
} )^m%i]L_
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privatestaticint getTotalPage(int everyPage, int bu
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totalRecords){ CsTF
int totalPage = 0; 9;_sC
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if(totalRecords % everyPage == 0) \Kl+ 5%L
totalPage = totalRecords / everyPage; %<E$,w>
else e<=cdze
totalPage = totalRecords / everyPage + 1 ; [onGNq?#
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return totalPage; Av"R[)
} "$N#p5
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privatestaticboolean hasPrePage(int currentPage){ qR(\5}
return currentPage == 1 ? false : true; (IC]?n}
} <<(wa
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privatestaticboolean hasNextPage(int currentPage, o=21|z
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int totalPage){ BnCbon)
return currentPage == totalPage || totalPage == Q,p}:e
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0 ? false : true; Kz>3
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} gUxP>hB
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} :X.b}^ Z(
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 hvA^n@nr
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 c/zJv*}x?
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做法如下: pcYG~pZ9
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 IkBei&4F`
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的信息,和一个结果集List: _acE:H
java代码: I
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/*Created on 2005-6-13*/ I 4,K43|
package com.adt.bo; NbC@z9Q
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import java.util.List; c:-!'l$ !
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import org.flyware.util.page.Page; kB'Fkqwm
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/** U}MXT<6
* @author Joa ^;/b+ /B0
*/ sB^<6W!`(
publicclass Result { TYJ:!
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private Page page; T{Sb^-H#X
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private List content; /[Z,MG
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/** )=AHf?hn
* The default constructor b!sRk@LGZ
*/ :lB=Lr)
public Result(){ 6
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super(); LM7$}#$R
} (xVsDAp=@
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/** E_8\f_%wK
* The constructor using fields blTo5NLX
* 1E73i_L
* @param page 9[m6Li
* @param content :E>HE,1b+
*/ 8"dv _`ym
public Result(Page page, List content){ q~3,yyu
this.page = page; |4T!&[r
this.content = content; E-I-0h2
} 6`]$qSTS
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/** D9FJ 1~
* @return Returns the content. vgUb{D
*/ 5m9*85Ib
publicList getContent(){ =dII- L=`
return content; )yTm.F
} QNARkYY~|
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/** hRty [
* @return Returns the page. WHjUR0NZ
*/ R}lsnX<
public Page getPage(){ [P 06lIO
return page; w9,iq@
} `FsH}UPu
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/** D3)zk@N
* @param content .h9l7
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* The content to set. " )V130<
*/ <