Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 n#jBqr&!M
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 3j'A.S
,EkzBVgo
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 W[pOLc-
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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 .hBq1p
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分页支持类: N_dHPa
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java代码: XRZj+muTZ
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package com.javaeye.common.util; Q5[x2 s_ d
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import java.util.List; bve_*7CEM
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publicclass PaginationSupport { ~UrKyA
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publicfinalstaticint PAGESIZE = 30; #[|~m;K(w
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privateint pageSize = PAGESIZE; j7(sYo@x7
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privateList items; kF%EJuu
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privateint totalCount; [i[*xf-B
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privateint[] indexes = newint[0]; a`c#-
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privateint startIndex = 0; 26SXuFJ@
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public PaginationSupport(List items, int `SFA`B)[5@
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totalCount){ A
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setPageSize(PAGESIZE); ew13qpt)<L
setTotalCount(totalCount); -L4fp
setItems(items);
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setStartIndex(0); $|kq{@<
} ^Rr!YnEN
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public PaginationSupport(List items, int 2C6o?*RjyY
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totalCount, int startIndex){ v'Y0|9c
setPageSize(PAGESIZE); &a;{ed1B
setTotalCount(totalCount); Ro}7ERA
setItems(items); ~]sj.>P
setStartIndex(startIndex); nt 9LBea
} zd%n)jlwR
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public PaginationSupport(List items, int X;e=d+pw
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totalCount, int pageSize, int startIndex){ 7aF'E1e'3
setPageSize(pageSize); ZmLA4<
setTotalCount(totalCount); ,/fB~On-
setItems(items); FUt{-H!<
setStartIndex(startIndex); \d'>Ky;GD
} x;^DlyyYU
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publicList getItems(){ |IcA8[
return items; 0oNNEC
} L3/SIoqd
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publicvoid setItems(List items){ %bN+Y'
this.items = items; :d AC:h
} }3825
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publicint getPageSize(){ JXx[e
return pageSize; Mb!b0
} w3n6md
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publicvoid setPageSize(int pageSize){ }WowgY
this.pageSize = pageSize; c-jE1y<
} {PGiNY%q
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publicint getTotalCount(){ \m xi8Z
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return totalCount;
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} {"dvU"y)\
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publicvoid setTotalCount(int totalCount){ >='y+68
if(totalCount > 0){ 0?$jC-@k:
this.totalCount = totalCount; /` ;rlH*
int count = totalCount / ;L*Ku'6Mt
+$uQ_ve
pageSize; .4[\%r\i
if(totalCount % pageSize > 0) _J,lF-,
count++; #\zC|%2+z
indexes = newint[count]; }'KHF0
for(int i = 0; i < count; i++){
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indexes = pageSize * #+"1">l
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i; r!N> FE
} C8Oh]JF4d
}else{ YigDrW
this.totalCount = 0; E%b*MU
} wbpz,
} W>_K+:t
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publicint[] getIndexes(){ ixvF`S9
return indexes; W"
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} `
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publicvoid setIndexes(int[] indexes){ 0Yk$f1g
this.indexes = indexes; yC:C
} qNuBK6E#4
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publicint getStartIndex(){ ,
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return startIndex; Q)/oU\
} WvoJ^{\4N*
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publicvoid setStartIndex(int startIndex){ 1F'x$~ZI
if(totalCount <= 0) 8C=8Wjm
this.startIndex = 0; gq7l>vT.
elseif(startIndex >= totalCount) ;u?L>(b
this.startIndex = indexes A4tb>OM
(|2:^T+
[indexes.length - 1]; oWLv-{08
elseif(startIndex < 0) ^Q#g-"b
this.startIndex = 0; B9:
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else{ 0woLB#v9
this.startIndex = indexes uj~(r=%
["H2H rI2
[startIndex / pageSize]; )i^S:2
} adn2&7H
} `'E(L&
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publicint getNextIndex(){ 0: Nw8J
int nextIndex = getStartIndex() + "oT&KW
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pageSize; adtgNwg
if(nextIndex >= totalCount) %BwvA_T'Q
return getStartIndex(); M,vCAZ
else L2Fi/UWM
return nextIndex; 4*&2D-8<K
} fyF8RTm{
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publicint getPreviousIndex(){ r'<!wp@
int previousIndex = getStartIndex() - ,UNnz&H+f
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pageSize; ++!'6!l
if(previousIndex < 0) 0i>>CvAl}
return0; <xlyk/
else Tl
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return previousIndex; FL[,?RU?2
} >aAsUL5W
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} 9>6?tb"f*H
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抽象业务类 YJF|J2u
java代码: .k"unclT0
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/** 97pfMk1_
* Created on 2005-7-12 f<;eNN
*/ Oh3A?!y#
package com.javaeye.common.business; x3l~k Z(
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import java.io.Serializable; KjK-#F,@
import java.util.List; iBk1QRdn
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import org.hibernate.Criteria; 629ogJo8
import org.hibernate.HibernateException; &3|l4R\
import org.hibernate.Session; (z:qj/|
import org.hibernate.criterion.DetachedCriteria; wln"g,ct
import org.hibernate.criterion.Projections; /], 9N
import +yxL}=4s
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org.springframework.orm.hibernate3.HibernateCallback; BUUc9&f3o
import =@P]eK/
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org.springframework.orm.hibernate3.support.HibernateDaoS Eih6?Lpu
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upport; !
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import com.javaeye.common.util.PaginationSupport; AEd9H
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public abstract class AbstractManager extends y9~:[ jB
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HibernateDaoSupport { _ZE&W
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privateboolean cacheQueries = false; A"6&
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privateString queryCacheRegion; GO3KKuQ=
qS?^(Vt|R
publicvoid setCacheQueries(boolean !
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cacheQueries){ V6&6I
this.cacheQueries = cacheQueries; J;N\q
} ~!P&LZ
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publicvoid setQueryCacheRegion(String j9R+;u/!
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queryCacheRegion){ Bo;{ QoB
this.queryCacheRegion =
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queryCacheRegion; -d[Gy-
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}
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publicvoid save(finalObject entity){ rQ(u@u;
getHibernateTemplate().save(entity); C[CNJ66
} $ve*j=p
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publicvoid persist(finalObject entity){ A]MX^eY
getHibernateTemplate().save(entity); M4e8PRlI
} ,4r 4 <
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publicvoid update(finalObject entity){ W$J@|i
getHibernateTemplate().update(entity); h>A~yDT[
} sC_doh_M
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publicvoid delete(finalObject entity){ zh5ovA%
getHibernateTemplate().delete(entity); F.AP)`6+*
} P:UR:y([
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publicObject load(finalClass entity, C8 y[B1Y
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finalSerializable id){ 7*r!-$
return getHibernateTemplate().load 0GQKM~|H
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(entity, id); or(P?Ro
} -HRa6
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publicObject get(finalClass entity, 2]E i4%jo
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finalSerializable id){ VuuF _y;
return getHibernateTemplate().get oGL2uQXX
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(entity, id); 'OU`$K7n
} S_;m+Ytg
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publicList findAll(finalClass entity){ 5k;}I|rg %
return getHibernateTemplate().find("from NYeL1h)l
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" + entity.getName()); =00sB
} _Nf%x1m5s
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publicList findByNamedQuery(finalString C|RC9b
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namedQuery){ mcWN.
return getHibernateTemplate b@B\2BT
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().findByNamedQuery(namedQuery); /5~j"|
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} G1:"Gxja
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publicList findByNamedQuery(finalString query, T+>W(w
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finalObject parameter){ juMHc$d17
return getHibernateTemplate "5"{~3Gw^
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().findByNamedQuery(query, parameter); ?>mpUH
} cK75Chsu
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publicList findByNamedQuery(finalString query, 5s<.qDc
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finalObject[] parameters){ C\*0621
return getHibernateTemplate OKnpG*)u=g
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().findByNamedQuery(query, parameters); jWK>=|)=c
} 54Vb[;`Kkb
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publicList find(finalString query){ UW&K\P
return getHibernateTemplate().find ~I@ %ysR
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(query); ootkf=
} 1$ENNq#0
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publicList find(finalString query, finalObject K*5Ij]j&
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parameter){ S^r[%l<'n
return getHibernateTemplate().find .]/k#Hv
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(query, parameter); c#a>> V
} (]$&.gE.F
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public PaginationSupport findPageByCriteria `eKFs0M.
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(final DetachedCriteria detachedCriteria){ uExYgI`<%&
return findPageByCriteria [pz1f!Wn
v"dl6%D"
(detachedCriteria, PaginationSupport.PAGESIZE, 0); jsq|K=x,
} lN7YU-ygz
}sM_^&e4X
public PaginationSupport findPageByCriteria >~uKkQ_p
! ~+mf^D
(final DetachedCriteria detachedCriteria, finalint O>IG7Ujl
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startIndex){ LHs^Xo18
return findPageByCriteria _!k\~4U
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(detachedCriteria, PaginationSupport.PAGESIZE, DS7Pioa86
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startIndex); SA~oGgk=P
} L/,M@1@R
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public PaginationSupport findPageByCriteria #^w8Y'{?
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to =
(final DetachedCriteria detachedCriteria, finalint @Z89cTO
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pageSize, 87hU#nVYh
finalint startIndex){ Xliw(B'\a4
return(PaginationSupport) u9{Z*w3L7
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getHibernateTemplate().execute(new HibernateCallback(){ =64Ju Wvo
publicObject doInHibernate avd`7eH2
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(Session session)throws HibernateException { !~]'&9
Criteria criteria = _J0(GuG=~
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detachedCriteria.getExecutableCriteria(session); #3YYE5cB
int totalCount = S>R40T=e
Zc=#Y
((Integer) criteria.setProjection(Projections.rowCount z"Wyf6H0T
>"D0vj
()).uniqueResult()).intValue(); V""3#Tw
criteria.setProjection SKJ'6*6
20 )8e!jP
(null); "Wy!,RH
List items = K?=g
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criteria.setFirstResult(startIndex).setMaxResults oi%IHX(`
xgWVxX^)
(pageSize).list(); D}?JX5.
PaginationSupport ps = t=n@<1d
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new PaginationSupport(items, totalCount, pageSize, _j]vR
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startIndex); V/J-zH&
return ps; A~8-{F 31
} R'aA\k-
}, true); 8-)@q|
} }QJ6"s
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public List findAllByCriteria(final D#11
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DetachedCriteria detachedCriteria){ 78E<_UgcB
return(List) getHibernateTemplate }nWW`:t kx
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().execute(new HibernateCallback(){ #a!qJeWm0
publicObject doInHibernate K}Lu1:~
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(Session session)throws HibernateException { S~{}jvc
Criteria criteria = /?:q9Wy
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detachedCriteria.getExecutableCriteria(session); 2bTM0-
return criteria.list(); 3NrWt2?
} i",oPz7
}, true); (Uk\O`)m
} zmU>
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public int getCountByCriteria(final ^ ]SU (kY
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DetachedCriteria detachedCriteria){ ]dnB,
Integer count = (Integer) I(+%`{Wv
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getHibernateTemplate().execute(new HibernateCallback(){ %F] :nk`
publicObject doInHibernate g#[,4o;
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(Session session)throws HibernateException { ^j7]> I
Criteria criteria = "=*
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detachedCriteria.getExecutableCriteria(session); E1>zKENN;
return j6BFh=?D
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criteria.setProjection(Projections.rowCount vtXZ`[D,l)
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()).uniqueResult(); mA6Nmq%{ F
} incUa;
}, true); ASaNac-3
return count.intValue(); tN&X1
} ;h7O_|<%
} E^t}p[s
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用户在web层构造查询条件detachedCriteria,和可选的 pAc "Wo(Q
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 x: 2 o$+v3
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PaginationSupport的实例ps。 \rmge4`4
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ps.getItems()得到已分页好的结果集 TRQH{O\O
ps.getIndexes()得到分页索引的数组 &y.6Hiy&
ps.getTotalCount()得到总结果数 )[5 .*g@
ps.getStartIndex()当前分页索引 k_7agW
ps.getNextIndex()下一页索引 q@Sj$
ps.getPreviousIndex()上一页索引 yx/.4DW1Ua
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 aKC3vR0
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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 ~bLhI
`r.
一下代码重构了。 Mt+ggF.
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我把原本我的做法也提供出来供大家讨论吧: ;.b^A
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首先,为了实现分页查询,我封装了一个Page类: rqYx\i?
java代码: !!UQ,yU
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/*Created on 2005-4-14*/ \k*h& :$
package org.flyware.util.page; lcEin*Oc
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/**
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* @author Joa Zcxj.F(,
* KZ/2#`
*/ 1IV
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publicclass Page { }
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/** imply if the page has previous page */ ,SSq4
privateboolean hasPrePage; o|7
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/** imply if the page has next page */ }A'Ro/n
privateboolean hasNextPage;
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{Aq:Kh`&
/** the number of every page */ dE|luN~
privateint everyPage; ,5t h D
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/** the total page number */ +
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privateint totalPage; 6T{SRN{
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/** the number of current page */ 2Jc9}|,
privateint currentPage; dX5|A_Ex
Rz!! ;<ye8
/** the begin index of the records by the current ~F=,)GE
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query */ cp<jwcc!
privateint beginIndex; 9aZ^m$tAt
}uk]1M2=
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/** The default constructor */ !0
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public Page(){ yaKw/vV
X"3Za[9j
} h5.AM?*TNd
c9)5G+
/** construct the page by everyPage lM-*{<B
* @param everyPage 2@#`x"0
* */ _=RK
public Page(int everyPage){ 1#
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this.everyPage = everyPage; c-hhA%@Wq
} Jl(G4h V'\
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/** The whole constructor */ :T# "bY
public Page(boolean hasPrePage, boolean hasNextPage, ;#Pc^Yzc1
ZMI
vzQYI
N"rZK/@}
int everyPage, int totalPage, dt|f4XWF
int currentPage, int beginIndex){ ~6-6aYhe
this.hasPrePage = hasPrePage; h`b[c.%
this.hasNextPage = hasNextPage; *]RCfHo\=
this.everyPage = everyPage; zCdzxb_h"
this.totalPage = totalPage; >gLLr1L\
this.currentPage = currentPage; f6zS_y9gn
this.beginIndex = beginIndex; JW-!m8
} 5D%gDw+"
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/** qmM%MPv
* @return wx%TQ!
* Returns the beginIndex. -C<Ni
*/ bem-T`>'
publicint getBeginIndex(){ 7JHS8C<]
return beginIndex; Kk_h&by?
} XT0:$0F
t?:Q
/** V_-{TGKX
* @param beginIndex $(U}#[Vie
* The beginIndex to set. 7f\@3r
*/ A T'P=)F@
publicvoid setBeginIndex(int beginIndex){ 2>!?EIE7
this.beginIndex = beginIndex; '4}c1F1T_
} O FCA~sR
v5N2$Sqp*
/** jwd{CN%
* @return c/\$AJV.H
* Returns the currentPage. #\)tz z
*/ yL>wCD,L
publicint getCurrentPage(){ t=Um@;wh
return currentPage; ,t=12R]>
} ,dO$R.h
)mb RG9P
/** XU19+mW=P
* @param currentPage J%n{R60b
* The currentPage to set. SS/t8Y4W
*/ SJdi*>
publicvoid setCurrentPage(int currentPage){ %">
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this.currentPage = currentPage; R1=ir# U|D
} mv+K!T6
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/** [M{EO)
* @return 3!V$fl0
* Returns the everyPage. p/f!\
*/ b-XC\
publicint getEveryPage(){ :xP$iEA`G
return everyPage; w(xRL#%
} 5Si\hk:o
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/** ,$qqHSd1M
* @param everyPage qm&Z_6Pw
* The everyPage to set. 7berkU0P
*/ 5h4E>LB.B
publicvoid setEveryPage(int everyPage){ %Fg}"=f1
this.everyPage = everyPage; g}]EIv{
} XN=Cq*3}
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/** t9Nu4yl
* @return *(4TasQu
* Returns the hasNextPage. Y/1,%8n
*/ 2iM8V
publicboolean getHasNextPage(){ n_Ka+Y<
return hasNextPage; ?98]\pI
} Dxwv\+7]
0y3<Ho,+$
/** !tNJLOYf
* @param hasNextPage Fc"&lk4e
* The hasNextPage to set. 7q] @Jx9
*/ k9^Vw+$m
publicvoid setHasNextPage(boolean hasNextPage){ #Rkld v'
this.hasNextPage = hasNextPage; )
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} XI*_ti
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/** Q#i^<WUpg
* @return XFg.Z+ #
* Returns the hasPrePage. 0kD8w j%
*/ Yv`8{_8L
publicboolean getHasPrePage(){ $qx&\@O
return hasPrePage; Sl{nS1q
} -*K!JC-
5w#*JK
/** '%m0@5|hCD
* @param hasPrePage 7(<49bb.V
* The hasPrePage to set. =!#iC?I
*/ 4#qjRmt
publicvoid setHasPrePage(boolean hasPrePage){ $pT%7jV}
this.hasPrePage = hasPrePage; Vd{h|=J
} #NVqS5
WR*|kh
/** Hhbf9)
* @return Returns the totalPage. ikGH:{
* yMNLsR~ rh
*/ LxGE<xj|V%
publicint getTotalPage(){ #c0
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return totalPage; l}DCK
} e<>Lr
@J~y_J{
/** G@)I
* @param totalPage )6?.; B
* The totalPage to set. !_`T8pJ`
*/ toipEp<ci
publicvoid setTotalPage(int totalPage){ !j(KbAhWZ
this.totalPage = totalPage; MGO.dRy_
} c#G]3vTdE
s'^zudx
} ;!@\|E
t#y
xX'Uq_Jv
ndm19M8Y|
I_yIVw;
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 !40t:+I
v`hv5wQ
个PageUtil,负责对Page对象进行构造: \ooqa<_
java代码: Gc9^Z=
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6,xoxNoPP3
/*Created on 2005-4-14*/ g)'tr
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package org.flyware.util.page; K.2M=Q
g[;iVX^1&
import org.apache.commons.logging.Log; \2<2&=h?
import org.apache.commons.logging.LogFactory; ISr~JQr
r1FE$R~C=
/** F.=uJdl.!
* @author Joa LeW.uh3.
* &,Q{l$`X
*/ fBH&AO$Q
publicclass PageUtil { skcMGEB
x
0
privatestaticfinal Log logger = LogFactory.getLog bIm$7a`T
ZW2#'$b
(PageUtil.class); K74oRKv
JMOP/]%D
/** 7/vr!tbL`p
* Use the origin page to create a new page ?E2k]y6<
* @param page ^BM/K&7^
* @param totalRecords %:o@IRTRU
* @return v%<_Mh
*/ fC3IxlG
publicstatic Page createPage(Page page, int s/[i>`g/9
ud:?~?j&w
totalRecords){ U30)r+&
return createPage(page.getEveryPage(), BHmA*3?
W7A'5
page.getCurrentPage(), totalRecords); 4Sg!NPuu7&
}
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/** ^qbX9.\
* the basic page utils not including exception +$>ut
r
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handler 5 J|;RtcR
* @param everyPage ~v>w%]
* @param currentPage e(
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* @param totalRecords (&MSP
* @return page :e@JESlLf
*/ 8VcAtrx_
publicstatic Page createPage(int everyPage, int W? UCo6<m
0h shHv-
currentPage, int totalRecords){ \N#)e1.0P
everyPage = getEveryPage(everyPage); xN"KSQpu
currentPage = getCurrentPage(currentPage); H[N&Wiq/|
int beginIndex = getBeginIndex(everyPage, ^z&xy41#B
iL 4SL}P
currentPage); J+*rjdI
int totalPage = getTotalPage(everyPage, !CBx$1z
\>=YxB q
totalRecords); J#V`W&\,6
boolean hasNextPage = hasNextPage(currentPage, w78Ius,
lIjHd#q-C
totalPage); Aq'%a)Y2
boolean hasPrePage = hasPrePage(currentPage); =cC]8Pz?
cn\& ;55v
returnnew Page(hasPrePage, hasNextPage, deTbvl
everyPage, totalPage, RO.(k!J .
currentPage, vWkKNB
"(efd~.]
beginIndex); x#8=drh.:C
} ,t+ATaOF
r3j8[&B"
privatestaticint getEveryPage(int everyPage){ A[ iPs9
return everyPage == 0 ? 10 : everyPage; 6vaxp|D
} $g$`fR)
3+|6])Hi1
privatestaticint getCurrentPage(int currentPage){ uBE,z>/,;
return currentPage == 0 ? 1 : currentPage; <Ab:yD`K!
} (Z"Xp{u
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privatestaticint getBeginIndex(int everyPage, int ONjc},_
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currentPage){ '6 'XBL?
return(currentPage - 1) * everyPage; {hg$?4IyQ
} k(qQvn
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privatestaticint getTotalPage(int everyPage, int ?^ErrlI_
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totalRecords){ !F<?h e<U
int totalPage = 0; ;%Da {
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if(totalRecords % everyPage == 0) YqJIp. Z
totalPage = totalRecords / everyPage; yX~[yH+Pn
else H0(zE*c~
totalPage = totalRecords / everyPage + 1 ; ;ZqFrHI M`
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return totalPage; E7h}0DX
} wKeqR$
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privatestaticboolean hasPrePage(int currentPage){ 3QHZC0AY
return currentPage == 1 ? false : true; {PVu3W
} Ksp;bfe
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privatestaticboolean hasNextPage(int currentPage, !>:tF,fcB
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int totalPage){ j>b OnCp~
return currentPage == totalPage || totalPage == r#Fu<so,
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0 ? false : true; >Qx#2x+
} 2>!ykUw^O
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} L,D>E
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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。 &rd(q'Vi
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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 P8VU&b\
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做法如下: LX fiSM{o
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Ww(_EW
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的信息,和一个结果集List: i`SF<)M(
java代码: 9>#|~P&FE
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/*Created on 2005-6-13*/ 0hkuBQb\
package com.adt.bo; 3PA'Uk"5Z
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import java.util.List; m%V[&"5%e
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import org.flyware.util.page.Page; dc>y7$2
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/** ?W
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* @author Joa :65HMWy.
*/ f$>orVm%.
publicclass Result { *e6|SZ &3
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private Page page; 1pb;A;F,A
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private List content; '/H(,TM
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/** jVINc=o
* The default constructor K*Jtyy}r
*/ I5L7BTe
public Result(){ #I?iR3u
super();
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} '| }}og
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/** jEsTw_
* The constructor using fields MQ*#oVqv
* DH
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* @param page S
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* @param content 0'hx w3#
*/ \Wc/kY3&
public Result(Page page, List content){ >y9o&D