Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 OTvROJP
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 I d8wS!W`7
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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*n==Nb5L
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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 JV"NZvjN7d
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分页支持类: PB'0?b}fab
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java代码: mL L$|
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package com.javaeye.common.util; _uH9XGm
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import java.util.List; 7|YrdK<
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publicclass PaginationSupport { _j#SpL'P
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publicfinalstaticint PAGESIZE = 30; $N+6h#
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privateint pageSize = PAGESIZE; Rph%*~'
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privateList items; _+QwREP
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privateint totalCount; W^g'}}]T
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privateint[] indexes = newint[0]; M=!i>(yG
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privateint startIndex = 0; 4I~i)EKy6
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public PaginationSupport(List items, int jp<VK<s]
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totalCount){ lglYJ,
setPageSize(PAGESIZE); -f>'RI95>
setTotalCount(totalCount); I lG:X)V%
setItems(items); \P?ToTTV
setStartIndex(0); @ RR\lZ
} R9dP ,<2
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public PaginationSupport(List items, int L'kq>1QWf
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totalCount, int startIndex){ hY8#b)l~lu
setPageSize(PAGESIZE);
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setTotalCount(totalCount); D[Iqn
setItems(items); u}jrfKdE
setStartIndex(startIndex); n.$(}A
} g'lT
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public PaginationSupport(List items, int H~9=&p[Q
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totalCount, int pageSize, int startIndex){ xfHyC'?
setPageSize(pageSize); !Tfij(91
setTotalCount(totalCount); oh\,OW
setItems(items); -CBD|fo[h
setStartIndex(startIndex); !oMt_k X
} RsSXhPk?
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publicList getItems(){ I6dm@{/:>
return items; d79N-O-
} s44iEh=V(I
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publicvoid setItems(List items){ k/`i6%F#m
this.items = items; lizTRVBE
} !IAKVQ
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publicint getPageSize(){ ki4f*Ej
return pageSize; B=zMYi
} Q=+8/b
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publicvoid setPageSize(int pageSize){ hZuYdV{'h
this.pageSize = pageSize; -V=arm\#z
} M\UWWb&%\
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publicint getTotalCount(){ :C%47qv
return totalCount; 9*p G?3*I
} 3%IWGmye4
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publicvoid setTotalCount(int totalCount){ zqGYOm$r
if(totalCount > 0){ |=3 *;}
this.totalCount = totalCount; ;nk@XFJ
int count = totalCount / Y><(?
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pageSize; (!n-Age
if(totalCount % pageSize > 0) Kym:J \}9B
count++; *i?.y*g
indexes = newint[count]; lIq~~cv)
for(int i = 0; i < count; i++){ Nmf#`+7gCI
indexes = pageSize * oQvFrSz
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i; V_]-`?S
} Yq;&F0paK
}else{ MVAc8d S
this.totalCount = 0; ,k%8yK
} nHU3%%%cU
} y h-9u
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publicint[] getIndexes(){ VRhRwdC
return indexes; A_Gp&acs$
} =g2\CIlVU6
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publicvoid setIndexes(int[] indexes){ h544dNo&
this.indexes = indexes; Kq6qXc\x
} b-b;7a\N
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publicint getStartIndex(){ +~:0Dxv W
return startIndex; N7B}O*;
} AzX(~Qc
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publicvoid setStartIndex(int startIndex){ s=j O;K$
if(totalCount <= 0) `w=!o.1
this.startIndex = 0; p;ZDpR
elseif(startIndex >= totalCount) f[M"EMy
this.startIndex = indexes Ap,q
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[indexes.length - 1]; 6cZ C
elseif(startIndex < 0) UJs?9]x>
this.startIndex = 0; j)@oRWL<
else{ 0C7" 3l
this.startIndex = indexes EQ~I'#m7
8 )`5P\
[startIndex / pageSize]; qid1b
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} "2K|#,%N
} _Fvsi3d/
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publicint getNextIndex(){ %>]#vQ|
int nextIndex = getStartIndex() + =z%s8D2
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pageSize; P#9-bYNU
if(nextIndex >= totalCount) JgZdS-~
return getStartIndex(); "U{mMd!9L
else +{bh
return nextIndex; gU*I;s>
} > hesxC!
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publicint getPreviousIndex(){ vev8l\
int previousIndex = getStartIndex() - :if5z2PE/
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pageSize; l?N`V2SuR
if(previousIndex < 0) o}W7.7^2
return0; L/%xbm~
else ;WPI+`-
return previousIndex; E<P*QZ-C3
} 4t(QvIydA
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} |O^V)bZmx
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抽象业务类 UvoG<;
java代码: K
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/** gB'`I(q5.
* Created on 2005-7-12 ;vZ*,q6
*/ $Jt8d|UP
package com.javaeye.common.business; K T"h74@
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import java.io.Serializable; gS0,')w
import java.util.List; H==X0
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import org.hibernate.Criteria; HXz iDnj
import org.hibernate.HibernateException; -1dIZy
import org.hibernate.Session; zbdOCfA;
import org.hibernate.criterion.DetachedCriteria; qrOB_Nz
import org.hibernate.criterion.Projections; ([E#zrz%
import 4_Tb)?L+:
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org.springframework.orm.hibernate3.HibernateCallback; A89Y;_4y
import 4{uJ||!
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org.springframework.orm.hibernate3.support.HibernateDaoS 30:HRF(:
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upport; lb=2*dFJ1
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import com.javaeye.common.util.PaginationSupport; 6B4hSqjh
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public abstract class AbstractManager extends D]3bwoFo&u
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HibernateDaoSupport { )I^)*(}
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privateboolean cacheQueries = false; w?*'vF_2:#
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privateString queryCacheRegion; $v2S;UB v*
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publicvoid setCacheQueries(boolean \Or]5ogT'
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cacheQueries){ })Ix.!p
this.cacheQueries = cacheQueries; C8O7i[uc
} "@F*$JGT y
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publicvoid setQueryCacheRegion(String KI^ q 5D ?
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queryCacheRegion){ B`t)rBy
this.queryCacheRegion = R
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queryCacheRegion; *=r@vQ
} d{(s-
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publicvoid save(finalObject entity){ ^*j[&:d
getHibernateTemplate().save(entity); j58Dki->.
} PkZf(=-X
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publicvoid persist(finalObject entity){ {3_F fsg`
getHibernateTemplate().save(entity); Wl@0TUK
} S S7D1
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publicvoid update(finalObject entity){ 96^1Ivd
getHibernateTemplate().update(entity); `*.r'k2R
} w%!k?t,*]
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publicvoid delete(finalObject entity){ A@fshWrl%
getHibernateTemplate().delete(entity); U/v"?pg[
} Lk$Je
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publicObject load(finalClass entity, OdtbVF~
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finalSerializable id){ rVc
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return getHibernateTemplate().load NG4eEnic!a
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(entity, id); 4rGO8R
} Hj-<{#,
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publicObject get(finalClass entity, 0|qx/xo|-
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finalSerializable id){ w7.?zb !N
return getHibernateTemplate().get bRY4yT
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(entity, id); Eusf gU:
} ),W(TL
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publicList findAll(finalClass entity){ E:LQ!
return getHibernateTemplate().find("from 9|?(GG
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" + entity.getName()); nATfmUN
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} \I`=JKYT
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publicList findByNamedQuery(finalString 8{U]ATx'(
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namedQuery){ C$]%1<-Iv]
return getHibernateTemplate ,sQ0atk7ma
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().findByNamedQuery(namedQuery); o 0cc+
} (,)vak&t
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publicList findByNamedQuery(finalString query, e-duZ o
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finalObject parameter){ 0wa!pE"
return getHibernateTemplate Ot8S'cB1,$
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().findByNamedQuery(query, parameter); 0ga1Yr]
} GhfUCW%
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publicList findByNamedQuery(finalString query, Q,`2DHhK
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finalObject[] parameters){ 6{,K7FL
return getHibernateTemplate }G:uzud10
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().findByNamedQuery(query, parameters); h(N9RJ}
} J=Y( *D7Q
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publicList find(finalString query){ ]oWZ{#r2
return getHibernateTemplate().find H--*[3".
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(query); O+UV\
} Eg-Mm4o
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publicList find(finalString query, finalObject Kr}M>hF+|
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parameter){ PU/Br;2A
return getHibernateTemplate().find "3KSmb
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(query, parameter); R4rm>zisVX
} O|7{%5h
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public PaginationSupport findPageByCriteria &4Iqm(
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(final DetachedCriteria detachedCriteria){ i[BR(D&l_p
return findPageByCriteria i4n%EDQ
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); BC0c c[x
} 6/WK((Fd
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public PaginationSupport findPageByCriteria G*wW&R)
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(final DetachedCriteria detachedCriteria, finalint $rQFM[
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startIndex){ bCx1g/
return findPageByCriteria +]~w ?^h
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(detachedCriteria, PaginationSupport.PAGESIZE, H*
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startIndex); kI[O {<kQ
} SAxa7B/U2
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public PaginationSupport findPageByCriteria g KmRjK
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(final DetachedCriteria detachedCriteria, finalint i,b7Ft:F&
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pageSize, !7a^8
finalint startIndex){ &)f++(i
return(PaginationSupport) 6Cv2>'{S
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getHibernateTemplate().execute(new HibernateCallback(){ u$@I/q,ou
publicObject doInHibernate g!)LhE
@7Rt[2"e
(Session session)throws HibernateException { kpreTeA]
Criteria criteria = `6/Yf@b
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detachedCriteria.getExecutableCriteria(session); pZJQKTCG
int totalCount = C.e|VzQa
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((Integer) criteria.setProjection(Projections.rowCount D>#v 6XI
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()).uniqueResult()).intValue(); YU0HySP:
criteria.setProjection \t(r@qq
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(null); 0}7Rm>
List items = 7te!>gUW
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criteria.setFirstResult(startIndex).setMaxResults WUK.>eM0
96E7hp !:
(pageSize).list(); o/[yA3^
PaginationSupport ps =
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new PaginationSupport(items, totalCount, pageSize, h/bYtE
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startIndex); |iJZC
return ps; }/}`onRZ
} eHyuO)(xH1
}, true); h+u|MdOY\
} ez:o9)N4
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public List findAllByCriteria(final j%y+W{Q[
l
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DetachedCriteria detachedCriteria){ vc{]c
}
return(List) getHibernateTemplate f I-"8f0_
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().execute(new HibernateCallback(){ #_L&
publicObject doInHibernate #cF8)GC
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(Session session)throws HibernateException { G]DN!7]@g
Criteria criteria = eV=sDx
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detachedCriteria.getExecutableCriteria(session);
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return criteria.list(); T:~W.3
}
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}, true); PL_wa(}y]D
} eKti+n.
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public int getCountByCriteria(final 5$Q`P',*Ua
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DetachedCriteria detachedCriteria){ 4qcIoO
Integer count = (Integer) x[@3;_'K
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getHibernateTemplate().execute(new HibernateCallback(){ }`FC__
publicObject doInHibernate {Qmb!`F
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(Session session)throws HibernateException { N6
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Criteria criteria = &r%^wfp
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detachedCriteria.getExecutableCriteria(session); 92_H!m/
return ^X'7>{7Io
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criteria.setProjection(Projections.rowCount G.ARu-2's
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()).uniqueResult(); yf^gU*
} eV+wnE?SB5
}, true); g)6 k?Y
return count.intValue(); mBkQ
8e
} |Qm%G\oB?
} zVLi
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用户在web层构造查询条件detachedCriteria,和可选的 /[dAgxL
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 <rmV$_
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PaginationSupport的实例ps。 <Py/uF|
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ps.getItems()得到已分页好的结果集 RtQfE+
ps.getIndexes()得到分页索引的数组 .u3W]5M|
ps.getTotalCount()得到总结果数 n:)Y'52}
ps.getStartIndex()当前分页索引 {X"]92+
ps.getNextIndex()下一页索引 dg8\(G
ps.getPreviousIndex()上一页索引 E?o8'r
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 7)wq9];w
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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 D+PUi!
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一下代码重构了。 XKIJ6M~5k
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我把原本我的做法也提供出来供大家讨论吧: >maz t=,
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首先,为了实现分页查询,我封装了一个Page类: BEx^IQ2
java代码: - & r{%7
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/*Created on 2005-4-14*/ Bn:sN_N
package org.flyware.util.page; pz =Wq4l
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/** Rx2|VD
* @author Joa PyE<`E
* dBn.DU*B
*/ `d#_66TLr
publicclass Page { Xxw.{2Ji!q
:\RB ^3;
/** imply if the page has previous page */ V@f#/"u'
privateboolean hasPrePage; }1 ^.A84a
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/** imply if the page has next page */ IW*.B6Hw8
privateboolean hasNextPage; j
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/** the number of every page */ 1!#ZEI C
privateint everyPage; Pw.+DA
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/** the total page number */ 3|3lUU\I
privateint totalPage; }"tYb6*
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/** the number of current page */ +N:%`9}2V
privateint currentPage; Zv7)+Q
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/** the begin index of the records by the current SBt:
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query */ %)V3QnBO
privateint beginIndex; aH~"hB^e
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/** The default constructor */ ?OFvGd
public Page(){ <'33!8
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} \ S R
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/** construct the page by everyPage dx}!]_mlZ
* @param everyPage THVF@@q
* */ V"73^
public Page(int everyPage){ *^ BE1-
this.everyPage = everyPage; yD"sYT
} Mk;j"ZDF
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/** The whole constructor */ e#^by(1@}
public Page(boolean hasPrePage, boolean hasNextPage, >sq9c/}X
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IK);BN2<L
int everyPage, int totalPage, {]]I4a
int currentPage, int beginIndex){ ~gD]JiiA
this.hasPrePage = hasPrePage; HY:n{=o
this.hasNextPage = hasNextPage; 0Jr<>7Q1
this.everyPage = everyPage; lhU# /}Z
this.totalPage = totalPage; &D#v0!e~x
this.currentPage = currentPage; `x{gF8GV
this.beginIndex = beginIndex; KNhH4K2iP8
} DGnswN%n1
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/** {[+gM?
* @return cAS5&T<
* Returns the beginIndex. HS7!O
*/ EC0auB7G
publicint getBeginIndex(){ r{_'2Z_i
return beginIndex; Kkm7L-
} Khl7Ez
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/** YX(%jcj*
* @param beginIndex W%o){+,
* The beginIndex to set. x4K5
*/ FKP^f\!M
publicvoid setBeginIndex(int beginIndex){ j&9~OXYv
this.beginIndex = beginIndex; )d~Mag+
} *?S\0a'W@
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/** gFH_^~7i8p
* @return N>_7Ltw/
* Returns the currentPage. ia[wVxd
*/ ]F~5l?4u#
publicint getCurrentPage(){ Gmb57z&:
return currentPage; t
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} 6~s,j({^
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/** {mDaK&]Oh
* @param currentPage 5V0=-K
* The currentPage to set. ~oI49Q&{
*/ /zWWUl`:
publicvoid setCurrentPage(int currentPage){ +-"#GL~cC
this.currentPage = currentPage; HFazqQ[
} j.K yPWO
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/** k1<Py$9"
* @return 7)T+!>
* Returns the everyPage. m:t$&
*/
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publicint getEveryPage(){ ,rKN/{M!
return everyPage; DCm;dh
} Z7v~;JzC#
ocMf}"
/** ,#A,+!4
* @param everyPage ) E\pQ5&
* The everyPage to set. @l8?\^N
*/ g 0L 4
publicvoid setEveryPage(int everyPage){ UpITx]y?"m
this.everyPage = everyPage; [|YMnV<B
} ">o/\sXeH
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/** E_OLf%um
* @return x[X.// :
* Returns the hasNextPage. D7@10;F}[
*/ ^V:YNUqp#
publicboolean getHasNextPage(){ &Fi8@0Fh
return hasNextPage; La!PGZ{
} p4[W@JV
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/** 5FMKJ7sC9
* @param hasNextPage -H
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* The hasNextPage to set. H`P )
*/ L81"W`?
publicvoid setHasNextPage(boolean hasNextPage){ O
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this.hasNextPage = hasNextPage; 75F&s,4+
} 3"".kf,O5e
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/** _eF*8 /z
* @return Rm
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* Returns the hasPrePage. 8WH>
*/ KQqlM
publicboolean getHasPrePage(){ G`n-WP
return hasPrePage; zt8ZJlNK
} C"sa.#}
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/** [Yv5Sw
* @param hasPrePage U+ 8[Ia(t
* The hasPrePage to set. g N[r*:B
*/ #wo_
publicvoid setHasPrePage(boolean hasPrePage){ 4eKJ\Q=nX5
this.hasPrePage = hasPrePage; ;#+#W+0
} [kXe)dMX8
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/** ]Cj&C/(
* @return Returns the totalPage. aZ'p:9e
* xnLf R6B
*/ 8177x7UG2[
publicint getTotalPage(){ ?1d_E meG2
return totalPage; T:-Uy&pBEN
} R[Rs2eS_
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/** Mk?9`?g.
* @param totalPage
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* The totalPage to set. ~q/`Z)(yc
*/ 6B 8!2
publicvoid setTotalPage(int totalPage){ 8_uDxd
this.totalPage = totalPage; ;8A_-$
} H$;\TG@,
*-n$n
} <Z5prunov
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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 ^O?$}sr
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个PageUtil,负责对Page对象进行构造: D H/1 :H
java代码: ~5|a9HV:
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/*Created on 2005-4-14*/ H1w;Wb1se
package org.flyware.util.page; +V) (,f1
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import org.apache.commons.logging.Log; }A#FGH+
import org.apache.commons.logging.LogFactory; >?kt3.IQ!X
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/** ^8 z*f&g
* @author Joa *)w
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* J:>TV.TP
*/ xS.0u"[
publicclass PageUtil { u/MIB`@,
* T-XslI
privatestaticfinal Log logger = LogFactory.getLog 4uv }6&R
&O'yhAP] j
(PageUtil.class); 7fVVU+y
l})uYae/
/** d<whb2l
* Use the origin page to create a new page Ft]sTA+C
* @param page tpVtbh1)u
* @param totalRecords `R^)<v*
* @return $q+7,,"
*/ [fb -G5x
publicstatic Page createPage(Page page, int =#W{&Te;
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totalRecords){ 7(oxmv}#Q
return createPage(page.getEveryPage(), Lt*H|9
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page.getCurrentPage(), totalRecords); )S`A+M K]
} wCdUYgsPT"
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/** ?{FxbDp>
* the basic page utils not including exception M--6oR7
B}3s=+L@8
handler ,7'l$-r l
* @param everyPage s_]rje8`
* @param currentPage 2^juLXc|R
* @param totalRecords z*R"917
* @return page <uAqb Wu
*/ i#C?&
publicstatic Page createPage(int everyPage, int 6=zme6D
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currentPage, int totalRecords){ gU8'7H2
everyPage = getEveryPage(everyPage); &r_:n t
currentPage = getCurrentPage(currentPage); is6JS^Q
int beginIndex = getBeginIndex(everyPage, ZJx:?*0a
#)\KV7f!;
currentPage); "c}bqoN
int totalPage = getTotalPage(everyPage, Zw }7vD0
ld3,)ZY
totalRecords); oc15!M3$
boolean hasNextPage = hasNextPage(currentPage, D3jP hPy.
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totalPage); Z(V4"x7F
boolean hasPrePage = hasPrePage(currentPage); pIh@!C
} wiq?dr
returnnew Page(hasPrePage, hasNextPage, BKGwi2]Ry
everyPage, totalPage, ){6;o&CC:
currentPage, Z{e5 OJ
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beginIndex); 7`P(LQAr!
} J${wU@_%
*<9p88FpDU
privatestaticint getEveryPage(int everyPage){ \Oc3rJ(
return everyPage == 0 ? 10 : everyPage; 4u /?..L.
} Y#Hf\8r,d
> sUk6Z~
privatestaticint getCurrentPage(int currentPage){ al^ yCoB
return currentPage == 0 ? 1 : currentPage; _)p%
} f'}23\>
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privatestaticint getBeginIndex(int everyPage, int lD{9o2
)`L!eN
currentPage){ Z3I<
return(currentPage - 1) * everyPage; &3AGj,
} /at#[Pw~01
}U8H4B~UtY
privatestaticint getTotalPage(int everyPage, int +pDuRr
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totalRecords){ {gJOc,U4b
int totalPage = 0; ny#7iz/
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if(totalRecords % everyPage == 0) 8(ZQD+U(9F
totalPage = totalRecords / everyPage; KC
else ^^v\ T
totalPage = totalRecords / everyPage + 1 ; "F0,S~tZZ
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return totalPage; H1q>UU:
} AN^;~m ^
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privatestaticboolean hasPrePage(int currentPage){ [t0gX dU6
return currentPage == 1 ? false : true; 5~ jGF
} ^D\#*pIO
~(FyGB}
privatestaticboolean hasNextPage(int currentPage,
l_$~~z ~
(/Nw
int totalPage){ ]T+{]t
return currentPage == totalPage || totalPage == f^ nogw<z!
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0 ? false : true; Mq6"7L
} ~uV.jh
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} _<xU"8b"5
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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。 $S6AqUk$
?-*_v//g
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 )=8X[<^i
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做法如下: j#o0y5S
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 I2D<~xP~2+
]W]Vkkg]
的信息,和一个结果集List: w!tQU9+*
java代码: 5q"
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/*Created on 2005-6-13*/ aQkgkV;~
package com.adt.bo; CkIICx
KeY)%{
import java.util.List; Nqy',N
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import org.flyware.util.page.Page; :Bda]]Y=
QIGMP=!j
/** YpXUYNy
* @author Joa .~C*7_
*/ )7:2v1Xr]
publicclass Result { nB"q
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private Page page; %Wn/)#T|
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private List content; 9fyk7~V
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/** O Y /QA
* The default constructor ss
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*/ omY%sQ{)
public Result(){ <(;"L<?D<C
super(); s+^YGB
} mJ[LmQ<:
'V .4Nhd
/** $d4eGL2S
* The constructor using fields ^[lg1uMW
* _qM'm^z5
* @param page N%n#mV;
* @param content if
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*/ Nmns3D
public Result(Page page, List content){ YtE V8w_$
this.page = page; i$$\}2m{L
this.content = content; >\[sNCkf
} ^o65sM
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/** @C7#xGD
* @return Returns the content. ,NPU0IDG>
*/ 2r<UYB
publicList getContent(){ K4snpuhC
return content; GAEz
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} vNHMe{,u
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/** v`bX#\It
* @return Returns the page. )%f]`<