Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 {X_I>)Wg
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 d+ZXi'
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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 xdz 6[8d8
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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
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分页支持类: ~t$ng l$
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java代码: /eXiWa sQ
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package com.javaeye.common.util; F;kKn:X L
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import java.util.List; C@zG(?X
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publicclass PaginationSupport { @$;8k }
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publicfinalstaticint PAGESIZE = 30; Qnt9x,1m_
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privateint pageSize = PAGESIZE; \Y8 sIs
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privateList items; piuM#+Y\'S
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privateint totalCount; Iu5 9W>
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privateint[] indexes = newint[0]; 1w7XM0SHcn
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privateint startIndex = 0; "M\rO!f:
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public PaginationSupport(List items, int ^e;9_(
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totalCount){ HvKdV`bz
setPageSize(PAGESIZE);
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setTotalCount(totalCount); . &`YlK
setItems(items); >}2
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setStartIndex(0); /lPnf7
} =PNkzFUo
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public PaginationSupport(List items, int ~Z*7:bPN!^
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totalCount, int startIndex){ _5(1T%K)
setPageSize(PAGESIZE); +xsGa{`
setTotalCount(totalCount); "USzk7=&.
setItems(items); j72mm!
setStartIndex(startIndex); VlSM/y5
} ^6F, lS _t
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public PaginationSupport(List items, int )PYh./_2
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totalCount, int pageSize, int startIndex){ 9ZatlI,
setPageSize(pageSize); v6[VdWOx5
setTotalCount(totalCount); G51-CLM,
setItems(items); 7/k7V)
setStartIndex(startIndex); /"m#mhL
} ?z6K/'?
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publicList getItems(){ a#[gNT~[
return items; LpSF*xm
} }|N88PN
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publicvoid setItems(List items){ L+T7Ge
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this.items = items; "L1LL
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} ?TIi0;h
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publicint getPageSize(){ K :+q9;g
return pageSize; #w \x-i|
} >9i>A:
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publicvoid setPageSize(int pageSize){ }LQV2 hKTG
this.pageSize = pageSize; &)JoB
} \*qradgx$
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E
publicint getTotalCount(){ WS(m#WFQr
return totalCount; f8=qnY2j
} G(Hr*T%
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publicvoid setTotalCount(int totalCount){ 7+@-mJMP$D
if(totalCount > 0){ m .(\u?J
this.totalCount = totalCount; 1OMaY5F
int count = totalCount / XeY[;}9
9) $[W
pageSize; ,/TmTX--d
if(totalCount % pageSize > 0) IR:{ { (
count++; I@O9bxR?
indexes = newint[count]; P?c V d2Y
for(int i = 0; i < count; i++){ <1m`
indexes = pageSize * o"L8n(\
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i; %6^nb'l'C
} Qb%;
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}else{ hNkv lk'Ui
this.totalCount = 0; Vm8dX?
} "oFi+']*
} y;4g>ma0
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publicint[] getIndexes(){ H.C*IL9
return indexes; ]q[(z
} gW4fwE^
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publicvoid setIndexes(int[] indexes){ 4}cxSl]jf!
this.indexes = indexes; E4Ez)IaKyi
} n5BD0q
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publicint getStartIndex(){ 7r)]9_[(
return startIndex; +/kOUz/]
} B B'qbX3xK
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publicvoid setStartIndex(int startIndex){ 3fXrwmBT8
if(totalCount <= 0) c+T`X?.j
this.startIndex = 0; YRf$?xa
elseif(startIndex >= totalCount) vdB2T2F
this.startIndex = indexes i^Jw`eAmT
F^%\AA]8
[indexes.length - 1]; PO0Od z
elseif(startIndex < 0) m$(OQ,E
this.startIndex = 0; Mw-L?j0o[k
else{ W?P4oKsql*
this.startIndex = indexes M.Tp)ig\#
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[startIndex / pageSize]; wL>*WLfR
} +%KkzdS'
} #Z
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publicint getNextIndex(){ iyr8*L\
int nextIndex = getStartIndex() + 99By.+~pX
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pageSize; /38I(0
if(nextIndex >= totalCount) 77aUuP7Iw
return getStartIndex(); n_LK8
else TvT>UBqj=
return nextIndex; 3B,dL|q(@J
} Bz>f
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publicint getPreviousIndex(){ COw!a\Jl
int previousIndex = getStartIndex() - 0Bkz)4R
Cc`-34/%
pageSize; a MFUj+^
if(previousIndex < 0) tQUKw@@Q
return0; upZc~k!1\
else *&_cp]3-WF
return previousIndex; 5=p<"*zJ
} *3@8,~_tp
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} gM]E8%;{
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抽象业务类 Z02EE-A
java代码: )8}k.t>'s
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/** wTZ(vX*mK
* Created on 2005-7-12 %Ny1H/@Q1+
*/ sMUpkU-
package com.javaeye.common.business; 7F~g A74h
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import java.io.Serializable; /k RCCs8t}
import java.util.List; 52Dgul
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import org.hibernate.Criteria; wmXI8'~F&
import org.hibernate.HibernateException;
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import org.hibernate.Session; ;1nXJ{jKw
import org.hibernate.criterion.DetachedCriteria; +|pYu<OY
import org.hibernate.criterion.Projections; gae=+@z
import 5T( cy
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org.springframework.orm.hibernate3.HibernateCallback; gV\Y>y4v
import p8YOow7)
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org.springframework.orm.hibernate3.support.HibernateDaoS ohJDu{V
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upport; g=qaq
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import com.javaeye.common.util.PaginationSupport; h>cjRH?e
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public abstract class AbstractManager extends 3$5E1*ed
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HibernateDaoSupport { C|w<mryx
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privateboolean cacheQueries = false; %VR{<{3f
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privateString queryCacheRegion; g`C8ouy
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publicvoid setCacheQueries(boolean 7w8UnPuM
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cacheQueries){ s] ;P<
this.cacheQueries = cacheQueries; D2gyn-]\
} um_J%v6ER
" Qyi/r41
publicvoid setQueryCacheRegion(String *f>\X[wN
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queryCacheRegion){ W$;qhB
this.queryCacheRegion = ,2 W=/,5A
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queryCacheRegion; _j0xL{&&
} rbIYLVA+V
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publicvoid save(finalObject entity){ 3k(tv U+eC
getHibernateTemplate().save(entity); ?K2}<H-
} cTRtMk%^
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publicvoid persist(finalObject entity){ g"Ueo'd*
getHibernateTemplate().save(entity); c$BH`" <*
} K`<HZK
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publicvoid update(finalObject entity){ XD0a :T)
getHibernateTemplate().update(entity); P6ktA-Hv>
} LayK&RwL
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publicvoid delete(finalObject entity){ e<a*@
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getHibernateTemplate().delete(entity); :&:P4Y1
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}
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publicObject load(finalClass entity, *!*%~h8V
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finalSerializable id){ G{>PYLxOb
return getHibernateTemplate().load e"bzZ!c&~V
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(entity, id); ^ACrWk~UY
} J-uQF|
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publicObject get(finalClass entity, 2]5Li/
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finalSerializable id){ -{9mctt/gE
return getHibernateTemplate().get ;bg]H >$U7
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(entity, id); wQd8/&mmk
} dPf7o
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publicList findAll(finalClass entity){ 2cIKph
return getHibernateTemplate().find("from h*!oHS~/l
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" + entity.getName()); oJ3(7Sz
} +r;t]
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publicList findByNamedQuery(finalString 3"v>y]$U
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namedQuery){ K{`R`SXD
return getHibernateTemplate q+*\'H>
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().findByNamedQuery(namedQuery); xfI0P0+
} yE,qLiH
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publicList findByNamedQuery(finalString query, >$-YNZA
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finalObject parameter){ q165S
return getHibernateTemplate tK/,U
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().findByNamedQuery(query, parameter); Ok{1{EmP
} |:x,|>/
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publicList findByNamedQuery(finalString query, yZ)9Hd
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finalObject[] parameters){ Ev7v,7`z
return getHibernateTemplate bolG3Tf|
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().findByNamedQuery(query, parameters); E"S#d&9
} WG\
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publicList find(finalString query){ 2@
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return getHibernateTemplate().find G/(,,T}eG
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(query); _Y]Oloo('
} 4Otq3s34FT
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publicList find(finalString query, finalObject ^dhx/e%s
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parameter){ MMpId
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return getHibernateTemplate().find '7oCWHq[
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(query, parameter); GK1nGdT]
} Y*\h?p[,
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public PaginationSupport findPageByCriteria & /T}
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(final DetachedCriteria detachedCriteria){ "!AtS
return findPageByCriteria =SeQ- H#
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); Xa#.GrH6
} ^--R#$X
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public PaginationSupport findPageByCriteria Y%0rji
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(final DetachedCriteria detachedCriteria, finalint Kb{&a
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startIndex){ 0#8, (6
return findPageByCriteria 5Ww,vSCV)
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(detachedCriteria, PaginationSupport.PAGESIZE, \<T7EV.
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startIndex); hE`d@
} !z4I-a
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public PaginationSupport findPageByCriteria }[UH1+`L
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(final DetachedCriteria detachedCriteria, finalint Wex2Fd?DO
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pageSize, 4^:dmeMZ`
finalint startIndex){ -.MJ3
return(PaginationSupport) oi,KA
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getHibernateTemplate().execute(new HibernateCallback(){ glU9A39qx?
publicObject doInHibernate ^AJ
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(Session session)throws HibernateException { <a
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Criteria criteria = (GL'm[V
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detachedCriteria.getExecutableCriteria(session); C R?}*
int totalCount = RHNAHw9
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((Integer) criteria.setProjection(Projections.rowCount ftPhE)i
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()).uniqueResult()).intValue(); $!9/s S?
criteria.setProjection XXA'B{@Y)
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(null); ^w``(-[*
List items = Vq`/]&
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criteria.setFirstResult(startIndex).setMaxResults cl&?'`
)
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(pageSize).list(); _xi&%F/
PaginationSupport ps = t g-(e=S4P
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new PaginationSupport(items, totalCount, pageSize, 047PlS
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startIndex); M!!vr8}
return ps; !]A/ID0K
} N5=}0s]e
}, true); ^mFsrw
} w_@{v wM$A
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public List findAllByCriteria(final iM:-750n/
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DetachedCriteria detachedCriteria){ .6
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return(List) getHibernateTemplate L[*cbjt[
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().execute(new HibernateCallback(){ Vraz}JV
publicObject doInHibernate nFG X2|d
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(Session session)throws HibernateException { W|rAn2H
Criteria criteria = 4f8XO"k7t=
@g;DA)!(
detachedCriteria.getExecutableCriteria(session); iWr
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return criteria.list(); lV4TFt,
} \eQPvkx2
}, true); =+T0[|gc(r
} ,98 F
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public int getCountByCriteria(final VZ`YbY
tS3&&t
DetachedCriteria detachedCriteria){ AT3HHQD
Integer count = (Integer) DaHbOs_<
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getHibernateTemplate().execute(new HibernateCallback(){ U*sQ5uq
publicObject doInHibernate [kr-gV
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(Session session)throws HibernateException { #EE<MKka
Criteria criteria = /@&o%I3h
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detachedCriteria.getExecutableCriteria(session); =B;qy7?
return P~:^bU^F7
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criteria.setProjection(Projections.rowCount u R5h0Fi
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()).uniqueResult(); iY2q^z/S
} q^wSM
}, true); Hi~)C \
return count.intValue(); G^K;+& T
} 4K`b?{){+a
} 4s_5>r4
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用户在web层构造查询条件detachedCriteria,和可选的 lcReRcjm
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 &vN!>bR
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PaginationSupport的实例ps。 #X$s5H
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ps.getItems()得到已分页好的结果集 8JR&s
ps.getIndexes()得到分页索引的数组 Da6l=M
ps.getTotalCount()得到总结果数 |)%H_TXTy
ps.getStartIndex()当前分页索引 46 \!W(O~y
ps.getNextIndex()下一页索引 '4~I%Z7L
ps.getPreviousIndex()上一页索引 a"g\f{v0AR
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 3bo
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 z/QYy)_j
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一下代码重构了。 OR|Jc+LT
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我把原本我的做法也提供出来供大家讨论吧: E|_8#xvb
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首先,为了实现分页查询,我封装了一个Page类: Q/j#Pst
java代码: I*cb\eU8Y
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/*Created on 2005-4-14*/ DOkuT/+
package org.flyware.util.page; v6L]3O1
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/** 5K$<Ad4$b
* @author Joa ).e}.Z6[i`
* ^4\0,>
*/ e(b$LUV
publicclass Page { r6aIW8
2*
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/** imply if the page has previous page */ D88IU9V&n
privateboolean hasPrePage; r[7*1'.p
,->5 sJ{U
/** imply if the page has next page */ TMsCl6dB
privateboolean hasNextPage; tBl(E
^x^(Rk}|
/** the number of every page */ l)jP!k
privateint everyPage; f$dIPt(
fWs*u[S
/** the total page number */ s+&0Z3+
privateint totalPage; sP%b?6
TA:#K
/** the number of current page */ -3b_}by
privateint currentPage; j:2F97
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/** the begin index of the records by the current }rs>B,=*k
RVs=s}|>*
query */ Clap3E|a
privateint beginIndex; >+!Ef
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/** The default constructor */ e$`hRZ%
public Page(){ WW^+X~Y
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} I};*O6D`
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/** construct the page by everyPage TK~KM
* @param everyPage @" umY-1f
* */ ,69547#o
public Page(int everyPage){ Q+QD,
this.everyPage = everyPage; -m
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} 08%Bx~88_%
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/** The whole constructor */ 37jrWe6xwp
public Page(boolean hasPrePage, boolean hasNextPage, })J}7@VPO
# Oq.}x?i
|*-<G3@
int everyPage, int totalPage, <viC~=k;
int currentPage, int beginIndex){ H(M{hfa|
this.hasPrePage = hasPrePage; m"'`$ /_
this.hasNextPage = hasNextPage; +~y>22Zfg
this.everyPage = everyPage; ,LmP >Q.
this.totalPage = totalPage; Ra
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this.currentPage = currentPage; :l iDoGDi
this.beginIndex = beginIndex; &rX#A@=
} C[#C/@
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>Sz}
/** ;mwnAO
* @return %p&y/^=0I
* Returns the beginIndex. iY&I?o!Ch
*/ E8p,l>6(f
publicint getBeginIndex(){ Mk+G(4p
return beginIndex; +#< Z/
} M1*bT@6
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n
/** QH,(iX6RY
* @param beginIndex o?a3hD
* The beginIndex to set. "QiLu=Rq
*/ [9NrPm3d
publicvoid setBeginIndex(int beginIndex){ CHD.b%_|
this.beginIndex = beginIndex; A&WC})H5
} `c-omNu
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/** \[*q~95$v
* @return /Bh*MH
* Returns the currentPage. ?k;htJcGv
*/ &CN(PZv
publicint getCurrentPage(){ h@(+(fVHrp
return currentPage; n}(A4^=4KQ
} K1]3zLnS
*-Vr=e<8
/** %yk_(3a
* @param currentPage o[+t}hC[
* The currentPage to set. wArfnB&
*/ 6f
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publicvoid setCurrentPage(int currentPage){ Vry_X2
this.currentPage = currentPage; HSAr6h
} 6h %rt]g
wp>
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/** @>V;guJC%
* @return DZ`m{l3H
* Returns the everyPage. YgS,5::SU
*/ >'.: Acn
publicint getEveryPage(){ rzLW@k
return everyPage; zEukEA^9`
} {s*2d P)
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/** \^RKb-6n
* @param everyPage UF*R1{
* The everyPage to set. P~iZae
*/ ',LC!^:~Nw
publicvoid setEveryPage(int everyPage){ ?#z<<FR
this.everyPage = everyPage; <1<xSr
} 6DgdS5GhT_
oVPr`]
/** 4neO$^i8J
* @return Ek6g?rj_
* Returns the hasNextPage. c/v|e&q
*/ CA5`uh
publicboolean getHasNextPage(){ `+>K)5hrR
return hasNextPage; 2+~gZxHq
} :Q@/F;Z?
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/** 5/7(>ivn
* @param hasNextPage mw;4/
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* The hasNextPage to set. 0(:SEiz6s
*/ FOMJRq
publicvoid setHasNextPage(boolean hasNextPage){ |\G^:V[.
this.hasNextPage = hasNextPage; 1+XM1(|c`
} cGdYfi
(}.MB3`#C
/** /@\R
* @return DZ\K7-
* Returns the hasPrePage. N@}h
*/ ?2dI8bG
publicboolean getHasPrePage(){ |g!d[ct]
return hasPrePage; N2duhI6
} V %D1Q}X
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/** Qr4 D
* @param hasPrePage bcpsjUiy#
* The hasPrePage to set. 5I^;v;F
*/ `M 'tuQ
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publicvoid setHasPrePage(boolean hasPrePage){ ~ A=Gra
this.hasPrePage = hasPrePage; @7C.0>W_A
} N~l*//Ep
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/** 4nh=Dq[
* @return Returns the totalPage. fFr9]
* k{N!}%*2
*/ NX.5u8Pf
publicint getTotalPage(){ .8!\6=iJB
return totalPage; "* F`,I3
} ~QxW^DGa7]
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/** pq&[cA_w
* @param totalPage K%x]:|,>M
* The totalPage to set. IM/xBP
*/ x-X~'p'f
publicvoid setTotalPage(int totalPage){ W{tZX^|
this.totalPage = totalPage; u;c
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} i$PO#}
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} ljOY;WV3
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 qxu3y+po]
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个PageUtil,负责对Page对象进行构造: VwPoQ9pIS
java代码: "NGfT:HV
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/*Created on 2005-4-14*/ NjOUe?BQ
package org.flyware.util.page; R]&Csr#~
e(|Z<6
import org.apache.commons.logging.Log; #fns3=/H
import org.apache.commons.logging.LogFactory; W&%,XwkQ
[X!w@d= i
/** PS+~JwD Uc
* @author Joa 7H< IO`
* *URT-+'
*/ tzIP4CR~F&
publicclass PageUtil { 111A e*U
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privatestaticfinal Log logger = LogFactory.getLog L6{gwoZf3
F=1 #qo<?
(PageUtil.class); yxp,)os:
P@vUQ
/** L-D4>+
* Use the origin page to create a new page ob;|%_
* @param page z06,$OYz
* @param totalRecords /YHO"4Z
* @return d-+jb<C&
*/ o9"?z
publicstatic Page createPage(Page page, int U{M3QOF
@=dv[P"jn
totalRecords){ x0(bM g>7
return createPage(page.getEveryPage(), 2(@2z[eKr
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page.getCurrentPage(), totalRecords); |`#fX(=
} 0
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L#byYB;E{
/** T[k$ [
* the basic page utils not including exception |y eQz
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handler 6` TwP\!$/
* @param everyPage Z}uY%]
* @param currentPage )-Hs]D:
* @param totalRecords i:0v6d
* @return page {eaR,d~X
*/ k!0O[U
publicstatic Page createPage(int everyPage, int g}D)MlXRq
nco.j:
currentPage, int totalRecords){ hoqZb<:
everyPage = getEveryPage(everyPage); 9>S)*lU&s
currentPage = getCurrentPage(currentPage); bN zb#P#hP
int beginIndex = getBeginIndex(everyPage, iiIns.V
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currentPage); bAZoi0LR
int totalPage = getTotalPage(everyPage, kP&I}RY
^py=]7[I
totalRecords); ya8p
4N{_
boolean hasNextPage = hasNextPage(currentPage, Mp|Jt
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totalPage); e,e(t7c?d
boolean hasPrePage = hasPrePage(currentPage); 'QT~o-U
?`Yu~a{
returnnew Page(hasPrePage, hasNextPage, .k]`z>uv
everyPage, totalPage, )0exGx+:
currentPage, Gd%i?(U,R
_)
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beginIndex); xyk%\&"7
} ?IHt T3'Rt
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privatestaticint getEveryPage(int everyPage){ ;kk[x8$
return everyPage == 0 ? 10 : everyPage; & mO n]
} rAu%bF
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privatestaticint getCurrentPage(int currentPage){ uNyN[U
return currentPage == 0 ? 1 : currentPage; 5cIZ_#
} rC^5Z
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privatestaticint getBeginIndex(int everyPage, int c#{lXS^
=6Ok4Z
currentPage){ H}F
UgA;
return(currentPage - 1) * everyPage; \+R %KA/F
} :$b` n
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privatestaticint getTotalPage(int everyPage, int l'EO@D/M
]i.N'O<p
totalRecords){ QX<n^W
int totalPage = 0; A,<5W }
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if(totalRecords % everyPage == 0) ,^?g\&f(
totalPage = totalRecords / everyPage; qhxMO[f
else hi!A9T3%}M
totalPage = totalRecords / everyPage + 1 ; >fXtu:C-!J
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return totalPage; eavn.I8J
} Ra|P5
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privatestaticboolean hasPrePage(int currentPage){ ):G%o
return currentPage == 1 ? false : true; U*=E(l
} SPb+H19;
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privatestaticboolean hasNextPage(int currentPage, f
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E,Rj;?
int totalPage){ :lB`K>)iB}
return currentPage == totalPage || totalPage == M/p9 I
gp
?0/$RpFEM#
0 ? false : true; x!_5/
} $UH:r
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} (Ut8pa+yX
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 ^\ x'4!W
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 #!F>cez
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Ez1
做法如下: S<i1t[E@W
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 n/5T{ NfG
,<%uG6/",g
的信息,和一个结果集List: EN2t}rua
java代码: 4C3_gm
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/*Created on 2005-6-13*/ ~ZVz
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package com.adt.bo; (BLxK)0<"
vd lss|
import java.util.List; DSwb8q
X=whZ\EZ
import org.flyware.util.page.Page; Q[#}Oh6$
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/** L=#NUNiXr
* @author Joa zfKO)Itd
*/ &K0b3AWc
publicclass Result { `CVkjLiy
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private Page page; z='%NZY
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private List content; /X_L>or
#Q!Xz2z2
/** m:h6J''<Z*
* The default constructor o+Jnn"8
*/ \+V"JIStUj
public Result(){ nv_v FK
super(); !4a fU:
} v]( Y n)#
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/** <9,h!
* The constructor using fields MG vz-E1e
* s9+):,dKP
* @param page ^ 4<