Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ;b[% L&
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 `]^JOw5o
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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 Os?`!1-
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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 3B(6^iS
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分页支持类: zkdyfl5
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java代码: 9:bC{n
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package com.javaeye.common.util; Xi'y-cV
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import java.util.List; "28b&pm
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publicclass PaginationSupport { bBkF,`/f$
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publicfinalstaticint PAGESIZE = 30; "lo:"y(u
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privateint pageSize = PAGESIZE; Uk u~"OGC
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privateList items; a;Q6S
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privateint totalCount; A0SEzX({[
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privateint[] indexes = newint[0]; :XK.A
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privateint startIndex = 0; V`V
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public PaginationSupport(List items, int "-Lbz)k
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totalCount){ !3{>
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setPageSize(PAGESIZE); C>q,c3s5
setTotalCount(totalCount); V:rq}F}
setItems(items); 2*6b{}yJH
setStartIndex(0); /jQW4eW0
} ZqQJFyV*
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public PaginationSupport(List items, int /wB<1b"
)+c4n]
totalCount, int startIndex){ K@P5]}'#
setPageSize(PAGESIZE); !HM|~G7
setTotalCount(totalCount); )miY>7K
setItems(items); 9 veq
setStartIndex(startIndex); H/>86GG
} ;E/:_DWPD
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m
public PaginationSupport(List items, int <@9p|[!
=PiDZS^"
totalCount, int pageSize, int startIndex){ 12*'rU;*
setPageSize(pageSize); AvdxDN
setTotalCount(totalCount); P
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setItems(items); ] Cpd`}'
setStartIndex(startIndex); MP\$_;&xB
} I"4j152P|
" d3pkY
publicList getItems(){ G\S\Qe{P~
return items; ngoo4}
} Paz
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publicvoid setItems(List items){ jk2h"):B>
this.items = items; L+7j4:$B8
} l@Vl^f~ P
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publicint getPageSize(){ UXVjRY`M.\
return pageSize; 6LRI~*F=3
} m!3L/UZ
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publicvoid setPageSize(int pageSize){ |ahleu
this.pageSize = pageSize; [#>ji+%=
} LuQ4TT
=.,]}
publicint getTotalCount(){ >cEc##:5
return totalCount; (i^3Lw :
} [L 0`B9TD~
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publicvoid setTotalCount(int totalCount){ B5>h@p-UV
if(totalCount > 0){ oR>o/$z$)g
this.totalCount = totalCount; U7d%*g
int count = totalCount / |e@9YDZ
@O#4duM4Qz
pageSize; CZ*c["x2
if(totalCount % pageSize > 0) jy`jxOoG~Z
count++; A-e#&pJ
indexes = newint[count]; 2mAXBqdm
for(int i = 0; i < count; i++){ i|PQNhUe
indexes = pageSize * AK\X{>$a!
jZu">Eh,
i; |><hdBQXX<
} = R|?LOEK+
}else{ )=TD}Xb
this.totalCount = 0; /NCEZ@2BN,
} xg~q'>
} _ETG.SYq
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publicint[] getIndexes(){ Mp*")N,
return indexes; kRs(A~ngc
} ,@ A1eX}
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publicvoid setIndexes(int[] indexes){ }:C4T*|
this.indexes = indexes; ri&B%AAc
} !={Z]J
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publicint getStartIndex(){ BX&bhWYGFX
return startIndex; [uP_F,Y/
} yC ZV:R;
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publicvoid setStartIndex(int startIndex){ M7BCBA
if(totalCount <= 0) `2\vDy1,j
this.startIndex = 0; kxt@t#
elseif(startIndex >= totalCount) |i'V\"
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this.startIndex = indexes Z- ;<R$
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[indexes.length - 1]; 1a4HThDXP
elseif(startIndex < 0) ?ihkV?;)
this.startIndex = 0;
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else{ +h^>?U,
this.startIndex = indexes |
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[startIndex / pageSize]; S(Md
} <U`lh
} u5^fiw]C
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publicint getNextIndex(){ Ijq1ns_tx8
int nextIndex = getStartIndex() + UR6.zE4=_
,<n >g;
pageSize; xlG/$`Ab
if(nextIndex >= totalCount) YIo$
return getStartIndex(); z><=F,W
else =zBcfFii`w
return nextIndex; o
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} q
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publicint getPreviousIndex(){
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int previousIndex = getStartIndex() - |SC^H56+
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pageSize; KCd}N
if(previousIndex < 0) %cMX]U
return0; ?WE#%W7U
else n[ip'*2L
return previousIndex; E>f+ E8?
} IMLk{y%6
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} d;O16xcM/
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抽象业务类 ogQY"c8
java代码: ei)ljvvmHP
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/** s>(OK.o
* Created on 2005-7-12 }eh<F^
*/ 7K3S\oPej
package com.javaeye.common.business; -b+VzVJZ
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import java.io.Serializable; Q!8AFLff4
import java.util.List; \}Fx''
r'xZF~}k"~
import org.hibernate.Criteria; QPf*!E
import org.hibernate.HibernateException; xo2PxUO
import org.hibernate.Session; heJ I5t,
import org.hibernate.criterion.DetachedCriteria; nN1\
import org.hibernate.criterion.Projections; Yy`\??,
import gV@FT|j!i
- &u]B$
org.springframework.orm.hibernate3.HibernateCallback; ! iuDmL
import Qa@b-v'by
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org.springframework.orm.hibernate3.support.HibernateDaoS U_ n1QU
=W'a6)WE
upport; %PozxF:
N>##}i
import com.javaeye.common.util.PaginationSupport; Zg1=g_xY
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public abstract class AbstractManager extends 0dxEV]
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HibernateDaoSupport { |?k3I/;
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privateboolean cacheQueries = false; ZHT_o\
o?(({HH
privateString queryCacheRegion; x01 n
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publicvoid setCacheQueries(boolean B M5+;h !
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cacheQueries){ S}6Ty2.\
this.cacheQueries = cacheQueries; )
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} t}L kl(
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publicvoid setQueryCacheRegion(String ;hb;%<xqT
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queryCacheRegion){ h>\T1PM
this.queryCacheRegion = \d$fi*{
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queryCacheRegion; C+ar]Vi
} C(-w A
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publicvoid save(finalObject entity){ {I'8+~|pZL
getHibernateTemplate().save(entity); FG/". dU
} KZoIjK]
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publicvoid persist(finalObject entity){ R-8>,
getHibernateTemplate().save(entity); \]RPxM:_>
} 6;s.%W
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publicvoid update(finalObject entity){
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getHibernateTemplate().update(entity); xgoG>~F
} | 4/'~cYV
!9A6DWA E$
publicvoid delete(finalObject entity){ `-@8IZ7
getHibernateTemplate().delete(entity); -PX Rd)~
} {*utke]}*
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publicObject load(finalClass entity, BUcPMF%\y:
vbEAd)*S
finalSerializable id){ )!SA]>-
return getHibernateTemplate().load 'fpm] *ig
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(entity, id); OsI>gX>
} oz3N
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publicObject get(finalClass entity, )CgKZ"
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finalSerializable id){ x\(@v
return getHibernateTemplate().get iF]G$@rbU
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(entity, id); ;75m 9yGo
} %siBCjvo=
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publicList findAll(finalClass entity){ 38ac~1HjE
return getHibernateTemplate().find("from Gy}WZ9{
dy/\>hu
" + entity.getName()); 5cahbx1"
} r'bctFsD
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publicList findByNamedQuery(finalString \"=4)Huv
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namedQuery){ oDz%K?29%
return getHibernateTemplate K"Vo'9R[_
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().findByNamedQuery(namedQuery); bloe|o!
} 2gP^+.
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publicList findByNamedQuery(finalString query, k;EG28
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finalObject parameter){ K4w %XVaH
return getHibernateTemplate C8ss6+k&
kyV!ATL1F
().findByNamedQuery(query, parameter); vh+ '
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} %3p~5jhm1
}
@r|o:I
publicList findByNamedQuery(finalString query, nV`n=x
*xHj*
finalObject[] parameters){ =AaTn::e/
return getHibernateTemplate }ACWSk WK
(!'=?B "
().findByNamedQuery(query, parameters); KWuc*!
} Eo
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publicList find(finalString query){ j&6O1
return getHibernateTemplate().find {7EnM1]
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(query); T2EQQFs
} =;tDYuFc!
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publicList find(finalString query, finalObject |76G#K~<X
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parameter){ ~HW8mly'
return getHibernateTemplate().find dP[vXhc
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(query, parameter); 6Bv!t2
} XFj\H(D
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public PaginationSupport findPageByCriteria o`tOnwt
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(final DetachedCriteria detachedCriteria){ aC!e#(q
return findPageByCriteria BH`%3Mw
4k$i:st;
(detachedCriteria, PaginationSupport.PAGESIZE, 0); ;dC>$_P?
} 0cGO*G2Xr
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public PaginationSupport findPageByCriteria =`&7pYd,
:A,g :B
(final DetachedCriteria detachedCriteria, finalint LgG7|\(-
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startIndex){ -_%8Q#"
return findPageByCriteria
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(detachedCriteria, PaginationSupport.PAGESIZE, 30BFwNE
s)dL^lj;
startIndex); !'
}
} cA,`!dG2,
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public PaginationSupport findPageByCriteria &XvSAw+D@
@%FLT6MY
(final DetachedCriteria detachedCriteria, finalint Q4;%[7LU
T
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pageSize, OV~]-5gau
finalint startIndex){ tVUC@M>'
return(PaginationSupport) <bvbfS
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getHibernateTemplate().execute(new HibernateCallback(){ 6H]rO3[8
publicObject doInHibernate {zckY
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(Session session)throws HibernateException { bUcEQGHcZ=
Criteria criteria = bU3P;a(
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detachedCriteria.getExecutableCriteria(session); crwui 8
int totalCount = sY-
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Q
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((Integer) criteria.setProjection(Projections.rowCount :m&cm%W]ts
6@rebe!&=
()).uniqueResult()).intValue();
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criteria.setProjection og?>Q i Tr
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(null); $.5f-vQp
List items = c4Leh"ry
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criteria.setFirstResult(startIndex).setMaxResults )qID<j#
D4G*Wz8
(pageSize).list(); hx.ln6=4
PaginationSupport ps = `GpOS_;
On`T
pz/
new PaginationSupport(items, totalCount, pageSize, 1(YEOZ
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startIndex); ?'8(']/
return ps; JmP[ 9"
} 7u=R5
}, true); fO UW{s
} -qJ%31Mr#
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public List findAllByCriteria(final mVs<XnA47
&i5MRw_]]
DetachedCriteria detachedCriteria){ sw\O\%^
return(List) getHibernateTemplate W5SCm(QS5
vyA
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().execute(new HibernateCallback(){ hI#1Ybl
publicObject doInHibernate }x~1w:zHd
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(Session session)throws HibernateException { wCitQ0?
Criteria criteria = AY(z9&;6
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detachedCriteria.getExecutableCriteria(session); o,q47W=7$
return criteria.list(); yQ03&{#
} 2uEvu
}, true); l ~C=yP(~
} w=Yc(Y:h
uE=pq<
public int getCountByCriteria(final `zP{E T_Y
Chs#}=gzi
DetachedCriteria detachedCriteria){ w9aLTLv-
Integer count = (Integer) B)`@E4i
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getHibernateTemplate().execute(new HibernateCallback(){ AzZb0wW6p
publicObject doInHibernate q(XO_1W0V
oro^'#ki
(Session session)throws HibernateException { DkA@KS1Dq
Criteria criteria = ,7/F?!G!J
s#*
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detachedCriteria.getExecutableCriteria(session); %+bw2;a6
return ytyX:e"
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criteria.setProjection(Projections.rowCount isR)^fI|
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()).uniqueResult(); %2ZWSQD
} [dIlt"2fV
}, true); *RllKP Y)
return count.intValue(); KB5<)[bs
} KmX?W/%R
} 3$n O@rOS
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用户在web层构造查询条件detachedCriteria,和可选的 {x\lK;
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 *1b1phh0/
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PaginationSupport的实例ps。 \(4kEB2s$
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ps.getItems()得到已分页好的结果集 ;Ob`B@!=b
ps.getIndexes()得到分页索引的数组 qZB}}pM#
ps.getTotalCount()得到总结果数 grZ?F~P8
ps.getStartIndex()当前分页索引 Ch0t'
ps.getNextIndex()下一页索引 :(TOtrK@
ps.getPreviousIndex()上一页索引 =C4!h'hz
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)+dd
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 )Rj,PF-9Z[
Y q(CD!
,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 5~H}%W,P
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一下代码重构了。 UC*\3:>'n
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我把原本我的做法也提供出来供大家讨论吧: {Q/_I@m].
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首先,为了实现分页查询,我封装了一个Page类: X775j"<d
java代码: i"GCm`
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/*Created on 2005-4-14*/ BW{&A&j
package org.flyware.util.page; Uy;e5<<
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/** 586lN22xM
* @author Joa q6AL}9]9
* t +h}hL
*/ <d]
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publicclass Page { m-AW}1:\f
i7|sVz=
/** imply if the page has previous page */ >,A&(\rO
privateboolean hasPrePage; e;r?g67
D&/~lhyNZ
/** imply if the page has next page */ 4&_|myO&
privateboolean hasNextPage; X{-901J1
IRY/0v
/** the number of every page */
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privateint everyPage; F&)(G\
~7O.}RP0
/** the total page number */ g"|/^G_6S
privateint totalPage; Bnu5\P
)^[PW&=W|x
/** the number of current page */ =q"o%dc`R
privateint currentPage; _d*QA{
jrLV \(p
/** the begin index of the records by the current ^#p+#_*V
K<~J*k<v
query */ O]-s(8Oo3
privateint beginIndex; x!;;;iS
$Y=xu2u)
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/** The default constructor */ z8*{i]j
public Page(){ 4u+4LB*
D\ kd6
} 2y#[uSqB
z3C@0v=u>
/** construct the page by everyPage }e8u p*#me
* @param everyPage l<dtc[
* */ JzZ@Z8%a;
public Page(int everyPage){ {-.ZFUZmT
this.everyPage = everyPage; &!0%"4
} wpV)y Q^
v i~NfD@s
/** The whole constructor */ Cy2)M(RW
public Page(boolean hasPrePage, boolean hasNextPage, .e1Yd8
k^e;V`(
lL6W:Fq@(
int everyPage, int totalPage, Y9ipy_@_?
int currentPage, int beginIndex){ bO6LBSZx]
this.hasPrePage = hasPrePage; <NlL,
this.hasNextPage = hasNextPage; MwO`DrV
this.everyPage = everyPage; zwJK|S k
this.totalPage = totalPage; NsUP0B}.
this.currentPage = currentPage; Uk<2XGj
this.beginIndex = beginIndex; zOsk'ZE&
} _6Qb 3tl
(\*+HZ`(Uu
/** hVf;{p
&
* @return P`]p&:
* Returns the beginIndex. q-R'5p\C?|
*/ (^9dp[2
publicint getBeginIndex(){ +A%"_7L}
return beginIndex; dH_g:ocA
} -YJ4-]Z
b1Fd]4H3P
/** U_61y;Q"
* @param beginIndex Z?j4WJy-[
* The beginIndex to set. 2YhtD A
*/ :WHbwu,L$
publicvoid setBeginIndex(int beginIndex){
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this.beginIndex = beginIndex; =+"=|cQ
} K3-Cuku
8XhGo2zf
/** y_}jf,b4
* @return <MzXTy3\
* Returns the currentPage. /& wA$h
*/ /@feY?glc
publicint getCurrentPage(){ &)GlLpaT
return currentPage; P)rz%,VF+
} _t.Ub:
M~LYq
/** T%[!m5
* @param currentPage Z<W`5sop^
* The currentPage to set. o*Kl`3=]
*/ .XPPd?R
publicvoid setCurrentPage(int currentPage){ c(r8
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this.currentPage = currentPage; zelM}/d
} ;|AyP
B~7]x;8h
/** WeE1 \
* @return 141XnAb)I
* Returns the everyPage. q~G@S2=}0}
*/ 1rGi"kdf
publicint getEveryPage(){ %IHra6
return everyPage; 3U&rK)F
} Bl*.N9*
kJK:1;CM?.
/** ZDTp/5=?K/
* @param everyPage ]B=2r^fn
* The everyPage to set. .$N8cYu0
*/ 3 Q~zli:
publicvoid setEveryPage(int everyPage){ p}d+L{"V
this.everyPage = everyPage; JxLSQ-"
} p$1y8Zbor
H0?Vq8I?
/** BX-fV|
* @return >%i]p
* Returns the hasNextPage. |tdsg
*/ H#FH'@J
publicboolean getHasNextPage(){ 7xoq:oP-}N
return hasNextPage; K}TSwY
} xF])NZy|
}e0>Uk`[
/** U2kl-E:
* @param hasNextPage thrv_^A
* The hasNextPage to set. XG;Dj<Dm
*/ @@} ]qT*
publicvoid setHasNextPage(boolean hasNextPage){ f&88N<)
this.hasNextPage = hasNextPage; <)VNEy'
} vCsJnKqK
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/** 08F~6e6a8
* @return I6RF;m:Jw
* Returns the hasPrePage. r
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*/ RE.t<VasP
publicboolean getHasPrePage(){ C[Nh>V7=
return hasPrePage; \3 M%vJ
} =sh3&8
~xU\%@I\
/** m`6=6(_p
* @param hasPrePage 3"p'WZ>
* The hasPrePage to set. ]=?.LMjnH
*/ mWX{I2
publicvoid setHasPrePage(boolean hasPrePage){ qz&?zzz;
this.hasPrePage = hasPrePage; u?lbC9}$
} 5 ]l8l+
TpAso[r
/** bguTWI8bk
* @return Returns the totalPage. f/UIpswrZ'
* F@rx/3
[
*/ $J!WuOz4^i
publicint getTotalPage(){ lOu&4Kq{g
return totalPage; )POU58$
} Uo=_=.GQ
/nz J`d
/** )UN_,'H/V
* @param totalPage R-OQ(]<*
* The totalPage to set. xY<*:&
*/ \CVrLn;}
publicvoid setTotalPage(int totalPage){ G}#p4\/
this.totalPage = totalPage; :[!b";pR
} ]Ia}H+ &
C1po]Ott*
} [J
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OXD*ZKi8
BT*{&'\/
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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 J{e`P;ND
6h{>U*N"&d
个PageUtil,负责对Page对象进行构造: gX;)A|9e
java代码: 8&c:73=?X
buA/G-<e
IyoitIbLl
/*Created on 2005-4-14*/ " mB
/"
package org.flyware.util.page; K-4o_:F
J>Bc-%.Q
import org.apache.commons.logging.Log; *IIuGtS
import org.apache.commons.logging.LogFactory; &2,^CG
Hd?#^X
/** %z"n}|%!
* @author Joa -I.BQ
* @H61^K<
*/
7;$[s6$
publicclass PageUtil { %&pd`A/
y_{fc$_&
privatestaticfinal Log logger = LogFactory.getLog M=#g_*d
SshjUNx
(PageUtil.class); Q(/F7"m
@|d+T"f
/** PXo^SHJ+gt
* Use the origin page to create a new page xaNM?]%
* @param page 2c%b
* @param totalRecords m*'87a9q0
* @return &FY7
D<
*/ Nc:0opPM
publicstatic Page createPage(Page page, int n |Q'>
2aJ_[3p/h]
totalRecords){ v?s%qb= T
return createPage(page.getEveryPage(), !n|4w$t"V
wPl9%
page.getCurrentPage(), totalRecords); Tno 0Q
+
} B~47mw&b
A+ LX37B
/** h]DzX8r}
* the basic page utils not including exception -~ H?R
{C5-M! D{<
handler =PYS5\k
* @param everyPage CSlPrx2\
* @param currentPage |Pq z0n=v
* @param totalRecords ]:svR@E
* @return page O7z5,-
*/ {9XQ~t"m^
publicstatic Page createPage(int everyPage, int H&uh$y@
FZx.Yuv
currentPage, int totalRecords){ q" @%W K
everyPage = getEveryPage(everyPage); SY$%)(c8kL
currentPage = getCurrentPage(currentPage); %OJq( }
int beginIndex = getBeginIndex(everyPage, MQq!<?/
Esdw^MGL2
currentPage); %nhE588xf
int totalPage = getTotalPage(everyPage, <F?UdMT4y
Jp-6]uW
totalRecords); C^7M>i
boolean hasNextPage = hasNextPage(currentPage, csj4?]gI
)}1S
`*J/O
totalPage); b_']S0$c\
boolean hasPrePage = hasPrePage(currentPage); 1;JH0~403
jS4fANG
returnnew Page(hasPrePage, hasNextPage, J=Hyoz+9
everyPage, totalPage, ^b6yN\,S
currentPage, *}=z^;_oq
RuWu#tk
beginIndex); V-x/lo]Co
} x,UP7=6
_zDf8hy
privatestaticint getEveryPage(int everyPage){ Xk }\-&C7
return everyPage == 0 ? 10 : everyPage; Y@limkN:
} lK3{~\J-
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privatestaticint getCurrentPage(int currentPage){ M?QX'fia
return currentPage == 0 ? 1 : currentPage; wW|[Im&
} ZiC~8p_f
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privatestaticint getBeginIndex(int everyPage, int cBQ+`DXn5c
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currentPage){ b=XHE1^rM
return(currentPage - 1) * everyPage; ?xw0kXK4
} v)<|@TD)
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privatestaticint getTotalPage(int everyPage, int (lt{$0
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totalRecords){ o ^""=Z
int totalPage = 0; V;uFYt;E
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if(totalRecords % everyPage == 0) .~fov8
totalPage = totalRecords / everyPage; t4<+]]
else *H~&hs>k
totalPage = totalRecords / everyPage + 1 ; 3M5wF6nY[[
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return totalPage; qv3% v3\4
} <\oD4EE_
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privatestaticboolean hasPrePage(int currentPage){ 3o`c`;H%p
return currentPage == 1 ? false : true; 4P^CqD&i
} v0KJKrliGO
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privatestaticboolean hasNextPage(int currentPage, J*t_r-z
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int totalPage){ sE! $3|Q
return currentPage == totalPage || totalPage == HM &"2c
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0 ? false : true; c+501's
} ,AwX7gx22
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 5=/j
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 iC~ll!FA!
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做法如下: .p(%gmOp#
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ~8U 0(n:^
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的信息,和一个结果集List: q_Z6s5O
java代码: Z6 E_Y?
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/*Created on 2005-6-13*/ 2b&Fu\2Dmv
package com.adt.bo; dP=,<H#]m
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import java.util.List; >DR$}{IV
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import org.flyware.util.page.Page; j[Gg[7q{y
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/** fT{%zJU
* @author Joa a(lmm@;V<
*/ X=V2^zrt
publicclass Result { 8=OpX,t(
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private Page page; }J $\<ZT
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private List content; wY3|5kbDj
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/** ^w_\D?
* The default constructor =3EjD;2
*/ 'oF
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public Result(){ }#6~/
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super(); }WHq?
} iw{^nSD
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/** ef2)k4)"
* The constructor using fields eIQ@){lJ-]
* eU\XAN#@
* @param page *z&hXYm
* @param content +*wr=9>
*/ t&~*!w!+jH
public Result(Page page, List content){ yz=aJ
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this.page = page; 5]zH!>-F
this.content = content; J~AmRo0!k
} KBa0
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/** & l0LW,Bx
* @return Returns the content. $hy0U_}6
*/ Q9i[?=F:z
publicList getContent(){ _gw paAJ
return content; Qh+zs^-?
} i5gNk)D
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