Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ~@"H\):/
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 id>2G
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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 1#|qT7
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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 'lOpoWDL
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。 :{aiw?1
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分页支持类: <#)Q.P
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java代码: c+
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package com.javaeye.common.util; H^jcWwy:
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import java.util.List; ~b6c:db3
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publicclass PaginationSupport { </2Cn@
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publicfinalstaticint PAGESIZE = 30; R3*{"!O
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privateint pageSize = PAGESIZE; jN/snU2\0
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privateList items; e[db?f2!
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privateint totalCount; <jh=W9.N_
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privateint[] indexes = newint[0]; ;S'1fci6
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privateint startIndex = 0; NOl/y@#
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public PaginationSupport(List items, int Xc<Hm
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totalCount){ ;Ao`yC2(v
setPageSize(PAGESIZE); l=<},_]{
setTotalCount(totalCount); u&e?3qKX(
setItems(items); w3"%d~/[x
setStartIndex(0); n9V8A[QJ
} Tz7|OV_W$
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public PaginationSupport(List items, int FaKZ|~Y
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totalCount, int startIndex){ )g ?'Nz
setPageSize(PAGESIZE); O:#/To'
setTotalCount(totalCount); Z OqD.=O(
setItems(items); LRSt >;
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setStartIndex(startIndex); }synU]^7\
} *56q4\1
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public PaginationSupport(List items, int {z@a{L:SC
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totalCount, int pageSize, int startIndex){
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setPageSize(pageSize); Mz;KXP
setTotalCount(totalCount); k>:\4uI|<\
setItems(items); &x/Z{ut
setStartIndex(startIndex); ,E2c9V'
} zT'(I6S:)
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publicList getItems(){ ;33SUgX
return items; J>fq5
} 5L,q,kVS
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publicvoid setItems(List items){ '^tC |)
this.items = items; )+f"J$ah
} sc z8`%
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publicint getPageSize(){ )O>M~
return pageSize; Q!h+1fb
} *nwH1FjH
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publicvoid setPageSize(int pageSize){ s^/2sjoL
this.pageSize = pageSize; 5oo6d4[
} nQG<OVRClS
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publicint getTotalCount(){ ?&POVf>
return totalCount; 22 `e7
} f+2mX"Z[F
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publicvoid setTotalCount(int totalCount){ `*cJc6
if(totalCount > 0){ 1vCVTuRF
this.totalCount = totalCount; Z.N9e
int count = totalCount / k-sBf Jy\
9} ]C
pageSize; _OB^ywHn.
if(totalCount % pageSize > 0) n%6=w9.%c
count++; H^g&e$d0
indexes = newint[count]; Vr #o]v
for(int i = 0; i < count; i++){ <SRo2rjRa
indexes = pageSize * ^CB@4$!
PrF('PH7i
i; ucUuhS5
} 5?TX.h9B4
}else{ )9+H[
this.totalCount = 0; E>F6!qYm
} peVzF'F
} UFeQ%oRa8
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publicint[] getIndexes(){ ^j<2s"S
return indexes; }p*WH$!~
} M+7jJ?n
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publicvoid setIndexes(int[] indexes){ ZC)m&V1
this.indexes = indexes; +>:[irf
} x/%/MFK)>8
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publicint getStartIndex(){ q[c^`5
return startIndex; W&2r{kCsQ
} Qi|k,1A0
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publicvoid setStartIndex(int startIndex){
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if(totalCount <= 0) D+7[2$:z
this.startIndex = 0; gY_AO1
elseif(startIndex >= totalCount) 'acCnn'
this.startIndex = indexes la`f@~Bbr1
vh^?M#\
[indexes.length - 1]; 'fY29Xr^
elseif(startIndex < 0) H
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this.startIndex = 0; ;Ehv1{;
else{ m4G))||9Q
this.startIndex = indexes K^%ONultv
*+ +}ll6
[startIndex / pageSize]; svMu85z
} 'Kd-A:K2g
} dRBWJ/ 1T
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publicint getNextIndex(){ 8/-hODoT_
int nextIndex = getStartIndex() + 5B;;{GR
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pageSize; _] us1
if(nextIndex >= totalCount) (_fovV=
return getStartIndex(); aQ0pYk~(
else ](z*t+">
return nextIndex; ,6x>gcR
} RF'&.RtVa
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publicint getPreviousIndex(){ l2kUa'O-
int previousIndex = getStartIndex() - 5PE}3he:
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pageSize; RIFTF
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if(previousIndex < 0) LPkl16yZ
return0; |^gnT`+
else Bm&6
return previousIndex; ;t4YI7E*
} `?SLp
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} ccy q~
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抽象业务类 Z5[g[Q
java代码: VBK |*Tl
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/** Bx|h)e9
* Created on 2005-7-12 rf]x5%ij
*/ rg I Z
package com.javaeye.common.business; 0+KSD{
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import java.io.Serializable; >*$Xbj*
import java.util.List; )<.y{_QUN
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import org.hibernate.Criteria; dAi.^! !
import org.hibernate.HibernateException; (SByN7[gb
import org.hibernate.Session; J#\oc@
import org.hibernate.criterion.DetachedCriteria; W4)bEWO+q
import org.hibernate.criterion.Projections; yn.[-
import cuL/y$+EY
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org.springframework.orm.hibernate3.HibernateCallback; l6.&<0pLT
import ?3<Y/Vg%c
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org.springframework.orm.hibernate3.support.HibernateDaoS LXf|n
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upport; c, }VC-
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import com.javaeye.common.util.PaginationSupport; 7nZ3u_~
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public abstract class AbstractManager extends c~!ETwpHQ
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HibernateDaoSupport { 877Kv);
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privateboolean cacheQueries = false; ;&MnPFmq
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privateString queryCacheRegion; kv<(N
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publicvoid setCacheQueries(boolean j? Vs"d|
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cacheQueries){ o+Q2lO5
this.cacheQueries = cacheQueries; aTs9lr:
} )*aAkM
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publicvoid setQueryCacheRegion(String Yh{5O3(;
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queryCacheRegion){ uFFC.w
this.queryCacheRegion = 2%)~E50U
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queryCacheRegion; ){KrBaGa4
} tMyMA}`
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publicvoid save(finalObject entity){ :bXTV?#0
getHibernateTemplate().save(entity); t|*UlTLm
} G^#?~
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publicvoid persist(finalObject entity){ 3V<c4'O\W
getHibernateTemplate().save(entity); 2m9qg-W
} VOT9cP^6
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publicvoid update(finalObject entity){ nPH\Lra
getHibernateTemplate().update(entity); $9Gra#
} <eZrb6a'
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publicvoid delete(finalObject entity){ F1p|^hYDW
getHibernateTemplate().delete(entity); L+0:'p=
} 97pnq1b
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publicObject load(finalClass entity, +^*b]"[
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finalSerializable id){ 5[~C!t;
return getHibernateTemplate().load V@K^9R,|
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(entity, id); n;y[%H!g
} #z}0]GJKj
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publicObject get(finalClass entity, EF;B)y=
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finalSerializable id){ pqe%tRH{
return getHibernateTemplate().get FA;B:O@:'
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(entity, id); kRH
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} ,<[x9 "3\
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publicList findAll(finalClass entity){ >E
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return getHibernateTemplate().find("from 3M>y.MS
rw75(Lp{
" + entity.getName()); |C>\ku*
} -o57"r^x
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publicList findByNamedQuery(finalString ^UyN)eX
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namedQuery){ ;|f]e/El
return getHibernateTemplate }MtORqK
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().findByNamedQuery(namedQuery); 4thPR}DH}
} `R*!GHro
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publicList findByNamedQuery(finalString query, 2
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finalObject parameter){ OOYdrv,
return getHibernateTemplate Vc+~yh.)
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().findByNamedQuery(query, parameter); M->#WGl\B
} ZL9|/
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publicList findByNamedQuery(finalString query, o@YEd d
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finalObject[] parameters){ mOFp!(
return getHibernateTemplate 5"D\n B%
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().findByNamedQuery(query, parameters); f?"909&
} Dc] J3r
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publicList find(finalString query){ <g, 21(bc
return getHibernateTemplate().find 51'V[tI;8
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(query); EpENhC0
} vb`:
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publicList find(finalString query, finalObject '(8}
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parameter){ :kXxxS
return getHibernateTemplate().find zF&_9VNk=c
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(query, parameter); %@%~<U)W
} ;!EEzR.
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public PaginationSupport findPageByCriteria p&HkR^.S
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(final DetachedCriteria detachedCriteria){ %}{.U
return findPageByCriteria U)1hC^[!
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); (dym*_J
} ^L'<%_#.
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public PaginationSupport findPageByCriteria IOl0=+p
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(final DetachedCriteria detachedCriteria, finalint d)0 hAdh
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startIndex){ ^{-Z3Yxd
return findPageByCriteria &p=(0$0&-
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(detachedCriteria, PaginationSupport.PAGESIZE, +^a@U^V
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startIndex); ShOB"J-
} %i&\X[
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public PaginationSupport findPageByCriteria :Y)G- :S+
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(final DetachedCriteria detachedCriteria, finalint UDb
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pageSize, Rz33_ qA
finalint startIndex){ Fh.ZsPn,m
return(PaginationSupport) `>`{DEDx{5
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getHibernateTemplate().execute(new HibernateCallback(){ &y ~GTEP
publicObject doInHibernate S|_lbMZM
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(Session session)throws HibernateException { |tO.@+[uqP
Criteria criteria = 7gt%[r M
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detachedCriteria.getExecutableCriteria(session); gn[h:+H&
int totalCount = N0fmC*1-
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((Integer) criteria.setProjection(Projections.rowCount 6!RKZj)
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()).uniqueResult()).intValue(); Na`vw
criteria.setProjection q?#w%0}
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(null); T2 V(P>E
List items = kk
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criteria.setFirstResult(startIndex).setMaxResults cA`X(Am6]g
_u;34H&/
(pageSize).list(); ~-NlTx
PaginationSupport ps = d C6t+
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new PaginationSupport(items, totalCount, pageSize, E D_J8+
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startIndex); J8hH#7WMS
return ps; 1@Rl^ey
} 5Veybchy "
}, true); =UFmN"
} QkY;O<Y_
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public List findAllByCriteria(final 200Fd8Ju
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DetachedCriteria detachedCriteria){ '>UQsAvm
return(List) getHibernateTemplate PL7_j
)7iYx {n
().execute(new HibernateCallback(){ @.KFWAm
publicObject doInHibernate fMZc_dsW9
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(Session session)throws HibernateException { }_cX" s
Criteria criteria = .T7S1C $HP
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detachedCriteria.getExecutableCriteria(session); +p &$`(
return criteria.list(); {IQCA-AI
} WSV% Oy3V
}, true); @ {8xL
} v ce1'aW
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public int getCountByCriteria(final MJ`BlE,Fmb
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DetachedCriteria detachedCriteria){ (k>I!Z/&2
Integer count = (Integer) YnX6U1/^
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getHibernateTemplate().execute(new HibernateCallback(){ O%busM$P)/
publicObject doInHibernate 'U4@Sax,
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(Session session)throws HibernateException { c`!8!R
Criteria criteria = /PtmJ2[
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detachedCriteria.getExecutableCriteria(session); yyuf
return X:gE
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criteria.setProjection(Projections.rowCount ZbLN:g}
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()).uniqueResult(); O.wk*m!9
} =VDtZSa!$^
}, true);
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return count.intValue(); H iDL:14
} YBY!!qjPx
} .k:Uj-&
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用户在web层构造查询条件detachedCriteria,和可选的 ;PG,0R`Z;
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 j?9fb
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PaginationSupport的实例ps。 ^1w*$5YI
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ps.getItems()得到已分页好的结果集 rJ_fg$.<
ps.getIndexes()得到分页索引的数组 '5m`[S-IU
ps.getTotalCount()得到总结果数 'Lv>!s 7
ps.getStartIndex()当前分页索引 "r.eN_d
ps.getNextIndex()下一页索引 ao.v]6a
ps.getPreviousIndex()上一页索引 nXcOFU
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 <MoKTP-<
@mrGG F
,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 LzJNQd'
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一下代码重构了。 :p,DAt}
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我把原本我的做法也提供出来供大家讨论吧: F
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首先,为了实现分页查询,我封装了一个Page类: ^J$?[@qD
java代码: q<*UeyE
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# ~T
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/*Created on 2005-4-14*/ G u P1
package org.flyware.util.page; 60&4?<lR4
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/** )rFcfS+/
* @author Joa ;NeN2 |I]
* q2KWSh5
*/ $mp'/]
publicclass Page { Ik74%x7G`
I4"U/iL51
/** imply if the page has previous page */ QnNddCiu=
privateboolean hasPrePage; p6e9mSs
X:Z*7P/
/** imply if the page has next page */ 6t(I.>-
privateboolean hasNextPage; dY%>C75O
>,. x'{
/** the number of every page */ 2Sg,b8
privateint everyPage; xnm!$ $W
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/** the total page number */ kan4P@XVS
privateint totalPage; m6=Jp<
^-i<TJ
/** the number of current page */ ;+h-o
privateint currentPage; '
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3m9ab"
/** the begin index of the records by the current )dgooq
-^%YrWgd?
query */ $"G=r(MW
privateint beginIndex; t&99ZdE
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/** The default constructor */ P<WCW3!JZ
public Page(){ p +>vX
X
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} K9(Su`zr
^sA"&Vdr^
/** construct the page by everyPage R8<'m
* @param everyPage f~NGIlgR
* */ p:n.:GZ=y
public Page(int everyPage){ EsR$H2"
this.everyPage = everyPage; 0cBk/x^s
} X}s}E
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/** The whole constructor */ &^4 E )F
public Page(boolean hasPrePage, boolean hasNextPage, +P?^Yx0d
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int everyPage, int totalPage, \h}a?T6
int currentPage, int beginIndex){ 2'6:fr=R
this.hasPrePage = hasPrePage; )HN,A z"
this.hasNextPage = hasNextPage; ] oh.w
this.everyPage = everyPage;
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this.totalPage = totalPage; TQ\\/e:
this.currentPage = currentPage; <CnTiS#
this.beginIndex = beginIndex; lZa L=HS#L
} C_JDQByfL
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/** uqg#(ADy?R
* @return Px<*n '~}
* Returns the beginIndex. L~])?d
*/ 3\Ma)\>R\-
publicint getBeginIndex(){ [Q=NGHB1/
return beginIndex; K !MIA
} N$i|[>`j
`>mT/Rmb@
/** v3vQfcxR
* @param beginIndex ^Q'^9M2)
* The beginIndex to set. A=5A8B1
*/ jK{)gO
publicvoid setBeginIndex(int beginIndex){ %w YGI
this.beginIndex = beginIndex; .s)z?31
} jml
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5|E_ ,d!v
/** c5t],P
* @return >pV|c\
* Returns the currentPage. JWuF ?<+k
*/ !VJ5(b
publicint getCurrentPage(){ 9<ev]XaSl
return currentPage; rprtp5C g
} xxN=,p
wwtk6;8@
/** mz~aSbb|
* @param currentPage i9FHEu_
* The currentPage to set. 0WjPo
*/ m:1f7Z>
publicvoid setCurrentPage(int currentPage){ ??!+2G#%!
this.currentPage = currentPage; _m+64qG_8'
} BrQXSN$i
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/** X~ AE??
* @return '<35XjW
* Returns the everyPage. c8'!>#$
*/ )OAd[u<
publicint getEveryPage(){ M@n9i@UsO
return everyPage; AJ*FQo.U
} AIR\>.~"i*
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/** xgi/,Nk '
* @param everyPage !\0UEC
* The everyPage to set. nM)q;9-ni
*/ _FET$$>z N
publicvoid setEveryPage(int everyPage){ ;c-J)Ky
this.everyPage = everyPage; Q@in?};
} 1Ue;hu'q:
V*m@Rs!)2
/** G@O~*k1v
* @return <L1;aNN
* Returns the hasNextPage. 0pSqk/
*/ |G5Me
publicboolean getHasNextPage(){ %b
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return hasNextPage; KKz{a{ePY%
} j5,vSh~q;'
AC$:.KLI
/** uH}cvshv
* @param hasNextPage o0nKgq'w|x
* The hasNextPage to set. J8T?=%?=
*/ EMDsi2
publicvoid setHasNextPage(boolean hasNextPage){ /idQfff
this.hasNextPage = hasNextPage; ="$9
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} MMMuT^X
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#;><
/** i U^tv_1
* @return <4gT8kQ$x
* Returns the hasPrePage. .."=
*/ D=w5Lks
publicboolean getHasPrePage(){ _oB!-#
return hasPrePage; O;u&>BMk
} ~"E@do("
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/** }4!R2c
* @param hasPrePage 8u,f<XHi"a
* The hasPrePage to set. E6{|zF/3'
*/ 5AWIk,[
publicvoid setHasPrePage(boolean hasPrePage){ 0$ -N
this.hasPrePage = hasPrePage; <Ct b^4$
} p?mQ\O8F
ohHKZZ
/** 3aL8 gE
* @return Returns the totalPage. zqaz1rt[
* =kp-[7
*/ io[$QTY
publicint getTotalPage(){ iUv#oX
H
return totalPage; T9@W,0#
} 1N#KVvK
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/** bp06xHMu
* @param totalPage uY,(3x
* The totalPage to set. TNA?fm
*/ 1rr\l`
publicvoid setTotalPage(int totalPage){ f\W1u#;u)
this.totalPage = totalPage; D0(%{S^
} _E[zYSo`
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} w&eX)!
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yw|O,V<4N
3x=f}SO&
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 3|=9aM^ x^
n+Ia@$|m
个PageUtil,负责对Page对象进行构造: nM+(
java代码: wic&
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6]=$c<.&
/*Created on 2005-4-14*/ vO85h
package org.flyware.util.page; : Gp,d*M
f$G{7%9*
import org.apache.commons.logging.Log; jl;%?bx
import org.apache.commons.logging.LogFactory; iRo/ ~(
" "GeO%J8
/** 9o|=n'o
* @author Joa 9sQ4
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* kKU,|>3h
*/ \/3Xb
publicclass PageUtil { VP|ga}(
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privatestaticfinal Log logger = LogFactory.getLog #K8kz
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(PageUtil.class); wI!>IV(5
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/** <P)vx
* Use the origin page to create a new page K,7IBv,B[
* @param page /8\gT(@
* @param totalRecords F;Q8^C0e*c
* @return tta\.ic
*/ O1+2Z\F
publicstatic Page createPage(Page page, int [b-wak})aD
>[]@Df,p
totalRecords){ l$ABOtM@
return createPage(page.getEveryPage(), ,J|8P{ZO
VTOZ#*f
page.getCurrentPage(), totalRecords); W0n/B&C
} o ]UG*2
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/**
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* the basic page utils not including exception P8lx\DA
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handler ZXP9{Hh
* @param everyPage 3g!tk9InG
* @param currentPage
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* @param totalRecords oe<9CK:?>
* @return page $Hr
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*/ o`hVI*D
publicstatic Page createPage(int everyPage, int iElE-g@Ws
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currentPage, int totalRecords){ ?lg
everyPage = getEveryPage(everyPage); w)A@
currentPage = getCurrentPage(currentPage); fiuF!<#;6
int beginIndex = getBeginIndex(everyPage, $q_e~+SXT
{H
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currentPage); O?<R.W<QI
int totalPage = getTotalPage(everyPage, oxN~(H)/ #
xh$1Rwa
totalRecords); FdR!jt
boolean hasNextPage = hasNextPage(currentPage, \ W3\P=
gxry?':
totalPage); U$;FOl
boolean hasPrePage = hasPrePage(currentPage); AV"fOK;#A
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returnnew Page(hasPrePage, hasNextPage, L*TPLS[lh
everyPage, totalPage, xz1jRI$
currentPage, kPt9(E]
yi7m!+D3
beginIndex); Z x9oj
} dd+[FU
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privatestaticint getEveryPage(int everyPage){ ?}y{tav=
return everyPage == 0 ? 10 : everyPage; y:6&P6`dx
} N*~G ]
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privatestaticint getCurrentPage(int currentPage){ qDR`)hle
return currentPage == 0 ? 1 : currentPage; *>x~`
} g<,kV(_7
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privatestaticint getBeginIndex(int everyPage, int Ij +
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currentPage){ "I"(yiKD
return(currentPage - 1) * everyPage; V2< 4~J2:9
} m_{?py@tZ
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privatestaticint getTotalPage(int everyPage, int OGgP~hd
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totalRecords){ K)m\xzT/
int totalPage = 0; *82f{t]
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if(totalRecords % everyPage == 0) p~ `f.q$'
totalPage = totalRecords / everyPage; cVrses^yE
else 9cJzL"yi
totalPage = totalRecords / everyPage + 1 ; ]s3U +t?
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return totalPage; h{ s- e.
} j7&57'
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privatestaticboolean hasPrePage(int currentPage){ ^rz8c+ly
return currentPage == 1 ? false : true; ![ &
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} bERYC|
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privatestaticboolean hasNextPage(int currentPage, jD@KG
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int totalPage){ |Qq_;x]
return currentPage == totalPage || totalPage == ,j{$SuZM
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0 ? false : true; jOuz-1x,&
} |Gc2w]\3
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} 9~8UG (
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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。 }@-4*5P3
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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 ekB!d
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做法如下: P4vW.|@
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 [[{y?-U
tx=~bm"*?
的信息,和一个结果集List: wO6`Ap
t1:
java代码: xngK_n
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/*Created on 2005-6-13*/ F\1{b N|3
package com.adt.bo; E|!rapa
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import java.util.List; n !ty\E
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import org.flyware.util.page.Page; 'Wv=mBEfZ
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/** -\mbrbG9H
* @author Joa 3c<).aC0f
*/ Y|bCbaF
publicclass Result { :-x F=Y(;
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private Page page; ]|cL+|':y
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private List content; b[<Q_7~2
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/** =i jGB~
* The default constructor :cv_G;?
*/ C^]y
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public Result(){ 5;=,BWU
super(); I 2JE@?
} ?(Dk{-:T'
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