Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 }cd-BW
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 =g<Y[Fi2
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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 f@H>by
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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 CooOBk
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分页支持类: TykY> cl
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java代码: >+F +"NAN
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package com.javaeye.common.util; H':0
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import java.util.List; C`b)}dY
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publicclass PaginationSupport { :8l#jU`y
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publicfinalstaticint PAGESIZE = 30; mL3 Q
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privateint pageSize = PAGESIZE; ?7Skk
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privateList items; ]Ag{#GJ5D
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privateint totalCount; xG|n7w*
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privateint[] indexes = newint[0]; O+PRP"$g"
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privateint startIndex = 0; yYPFk
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public PaginationSupport(List items, int 4S*7*ak{
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totalCount){ !y7w~UVs
setPageSize(PAGESIZE); LT6VZ,S
setTotalCount(totalCount); v0,&wdi
setItems(items); e|Mw9DIW
setStartIndex(0); $X]Z-RCK3
} R*>EbOuI
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public PaginationSupport(List items, int 7U`8W\-
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totalCount, int startIndex){ Ujfs!ikh&F
setPageSize(PAGESIZE); -< }#ImTN
setTotalCount(totalCount); M =6
setItems(items); %nT &
setStartIndex(startIndex); _[8sL^
} >|_B=<!99W
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public PaginationSupport(List items, int Fu"@)xw/-q
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totalCount, int pageSize, int startIndex){ AS]jJc^
setPageSize(pageSize); D}L4uz?
setTotalCount(totalCount); \!!1o+#1j
setItems(items);
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setStartIndex(startIndex); zJT,Hv .
} P(Z\y^S
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publicList getItems(){ A]AM|2 D
return items; ^5~)m6=2
} 9Lqo^+0)\
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publicvoid setItems(List items){ K])|
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this.items = items; X2to](\%X
} -`d(>ok
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publicint getPageSize(){ O`FuXB(t
return pageSize; AW/)R"+
} ]]lM)
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publicvoid setPageSize(int pageSize){ hsHtLH+@
this.pageSize = pageSize; n8 e4`-cY
} .9KW|(uW
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publicint getTotalCount(){
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return totalCount; O:Ob{k
} bZi;jl
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publicvoid setTotalCount(int totalCount){ iYl$25k/1
if(totalCount > 0){ @d_;p<\l
this.totalCount = totalCount; V9<CeTl'
int count = totalCount / (]*!`(_b
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pageSize; u}BN)%`B
if(totalCount % pageSize > 0) hP26 Bb1
count++; atWB*kqI
indexes = newint[count]; 6Rc%P)6
for(int i = 0; i < count; i++){ Z'|A>4\
indexes = pageSize * QE%|8UFY
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} AAld2"r
}else{ IX
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this.totalCount = 0; qD/FxR-!
} a@U0s+V&a0
} v}-j ls
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publicint[] getIndexes(){ lp%i%*EQ*
return indexes; +Y|HO[
} *r]Mn~3
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publicvoid setIndexes(int[] indexes){ h2#S ?
this.indexes = indexes; W(&9S[2
} PbN"+q M
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publicint getStartIndex(){ ]z_C7Y"4BR
return startIndex; {_5PN^J
} DC8,ns]!y
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publicvoid setStartIndex(int startIndex){ ,Jh('r7
if(totalCount <= 0) HRZ3}8Qj
this.startIndex = 0; I\peO/w
elseif(startIndex >= totalCount) |?
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this.startIndex = indexes n*U+jc
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[indexes.length - 1]; >!|(n@
elseif(startIndex < 0) Hxzdxwz%$
this.startIndex = 0; hg=BXe4:
else{ 1O]27"9
this.startIndex = indexes uSi/|
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[startIndex / pageSize]; *,=WaODO %
} MX#MDA-4
} Z`lCS
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publicint getNextIndex(){ s(Tgv
int nextIndex = getStartIndex() + 4yu ^cix(
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pageSize; |xQq+e}l<
if(nextIndex >= totalCount) M`kR2NCi
return getStartIndex(); "3Z<V8xB
else Q&Ox\*sMK
return nextIndex; *|DIG{
} ooPH [p
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publicint getPreviousIndex(){ N}2xt)JZz
int previousIndex = getStartIndex() - Fl^}tC
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pageSize; !.ot&EbE
if(previousIndex < 0) KU}HVM{
return0; Kzd`|+?'`M
else h7H#sL[^
return previousIndex; 'of5v6:8
} v|v^(P,o
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} 044*@a5f
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抽象业务类 gB?~!J?
java代码: ~CB6+t>
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/** }Rc8\,
* Created on 2005-7-12 SEc3`y;j%
*/ S6sw)
package com.javaeye.common.business; \KaWR
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import java.io.Serializable; &)p/cOiV
import java.util.List; Y+#e| x
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import org.hibernate.Criteria; *QF3l0&
import org.hibernate.HibernateException; <k^P>Irb3t
import org.hibernate.Session; $MmCh&V
import org.hibernate.criterion.DetachedCriteria; .qioEqK8!y
import org.hibernate.criterion.Projections; ReCmv/AE
import d&p]O
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j
org.springframework.orm.hibernate3.HibernateCallback; kxg]sr"
import a9q68
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org.springframework.orm.hibernate3.support.HibernateDaoS y^ gazr"
k]Y#-Q1p~
upport; `1NxS35u
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import com.javaeye.common.util.PaginationSupport; OT9\K_
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public abstract class AbstractManager extends S4]xxc
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HibernateDaoSupport { [Pdm1]":(
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privateboolean cacheQueries = false; ,0#5kc*X
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privateString queryCacheRegion; .d5|Fs~B
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publicvoid setCacheQueries(boolean W.ud<OKP90
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cacheQueries){ zJ#e3o .
this.cacheQueries = cacheQueries; 7"r7F#D=G
} -P 5VE0
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publicvoid setQueryCacheRegion(String 2oAPJUPOJ
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queryCacheRegion){ QY2!.a^q
this.queryCacheRegion = sa`7_KB
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queryCacheRegion; ih?_ fW
} +0=u]
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publicvoid save(finalObject entity){ w.cQ|_
getHibernateTemplate().save(entity); vL13~q*F
} }}?L'Vby
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publicvoid persist(finalObject entity){ :YB:)wV,P
getHibernateTemplate().save(entity); ML0o:8Bd\
} e:V(kzAY;
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publicvoid update(finalObject entity){ r +;C}[E
getHibernateTemplate().update(entity); jz|zq\Eek
} \qAMs^1-
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publicvoid delete(finalObject entity){ O!zH5
getHibernateTemplate().delete(entity); e+=Oj o#
} kRskeMr:Rd
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publicObject load(finalClass entity, T IPb ]
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finalSerializable id){ d'Z|+lq:
return getHibernateTemplate().load Z\xR+3
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(entity, id); /MSz{ %v
} uj&^W[s
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publicObject get(finalClass entity, !a3cEzs3
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finalSerializable id){ Tn/
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{
return getHibernateTemplate().get K3?7Hndf2
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(entity, id); Qg?^%O'
} E'$r#k:o
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publicList findAll(finalClass entity){ !5 %c`4
return getHibernateTemplate().find("from _p7c<$;
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" + entity.getName()); IQdiVj
} GFx>xQk
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publicList findByNamedQuery(finalString Gw3|"14
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namedQuery){ Rs8`M8(4%
return getHibernateTemplate D(}v`q{Y
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().findByNamedQuery(namedQuery); suaTXKjyk+
} J}KATpHs
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publicList findByNamedQuery(finalString query, 1I KDp]SN
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finalObject parameter){ 'HkV_d[li
return getHibernateTemplate cy?u
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().findByNamedQuery(query, parameter); M'HmVg4'
} hp,bfcM
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publicList findByNamedQuery(finalString query, G(|ki9^@"9
{DBgW},
finalObject[] parameters){ .5|wy<
return getHibernateTemplate E@R7b(:*
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().findByNamedQuery(query, parameters); N(]6pG=
} LwkZ (Tt
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publicList find(finalString query){ MH`f!%c
return getHibernateTemplate().find
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(query); qWtvo';3
} 5>"$95D
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publicList find(finalString query, finalObject @1gX>!
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parameter){ Cz
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return getHibernateTemplate().find me$7\B;wy
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(query, parameter); jUZ84Gm{
} _*9eAeJ
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public PaginationSupport findPageByCriteria PR{?l
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(final DetachedCriteria detachedCriteria){ wvcG <sj
return findPageByCriteria ; @-7'%(C
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); #)hM]=,e
} |JSj<~1ki
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public PaginationSupport findPageByCriteria ; a XcGa
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(final DetachedCriteria detachedCriteria, finalint &2Q4{i
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startIndex){ I/<aY*R4
return findPageByCriteria 55Y BO$
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(detachedCriteria, PaginationSupport.PAGESIZE, uYhm
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startIndex); c#
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} ^|Of
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public PaginationSupport findPageByCriteria cMsm[D{b
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(final DetachedCriteria detachedCriteria, finalint V"#ie
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pageSize, +tkDT@ `
finalint startIndex){ ,sn
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return(PaginationSupport) BEx?
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getHibernateTemplate().execute(new HibernateCallback(){ H.hF`n
publicObject doInHibernate >> Z.]
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(Session session)throws HibernateException { fDNiU"
Criteria criteria = vtK Qv Q
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detachedCriteria.getExecutableCriteria(session); _)yn6M'Dt
int totalCount = vXAO#'4tm%
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((Integer) criteria.setProjection(Projections.rowCount 7MZBU~,r
[DC8X P5<
()).uniqueResult()).intValue(); ?V4?r2$c
criteria.setProjection (q59cA w~X
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(null); >_jT.d
List items = JZNRMxu
7$b!-I+a2
criteria.setFirstResult(startIndex).setMaxResults BRPvBs?Q,{
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(pageSize).list(); IKMkpX!]
PaginationSupport ps = R7r` (c!
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new PaginationSupport(items, totalCount, pageSize, :$~)i?ge<5
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startIndex); "9jt2@<
return ps; aJ}y|+Cj
} k(pI5N}pJZ
}, true); X+z!?W*a
} P
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public List findAllByCriteria(final @#hd8_)A.
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DetachedCriteria detachedCriteria){ 'c*Q/C;
return(List) getHibernateTemplate ~,WG284
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().execute(new HibernateCallback(){ N_rz~$|@9
publicObject doInHibernate o|YY,G=C
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(Session session)throws HibernateException { Hm!ffqO_
Criteria criteria = :hr% 6K7
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detachedCriteria.getExecutableCriteria(session); % 4|*
return criteria.list(); gHpA@jdC*
} 0}C> e`<'
}, true); [nZf4KN
}
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public int getCountByCriteria(final zP$0B!9
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DetachedCriteria detachedCriteria){ kU{+@MA;
Integer count = (Integer) j*+[=X/
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getHibernateTemplate().execute(new HibernateCallback(){ I(tMw6C$:
publicObject doInHibernate OJ^kESrm8
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(Session session)throws HibernateException { d7waBsf
Criteria criteria = &*}`uJt
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detachedCriteria.getExecutableCriteria(session); vik A
return ;rXkU9
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criteria.setProjection(Projections.rowCount Q#w mS&$f
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()).uniqueResult(); h_#x@p
} }%Mj`Bh
}, true); W^#HR
return count.intValue(); <qJI]P
} B3|h$aKC
} O{b<UP'85
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用户在web层构造查询条件detachedCriteria,和可选的 ko<u0SjF)u
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ere h!
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PaginationSupport的实例ps。 7[z^0?Pygf
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ps.getItems()得到已分页好的结果集 qaJ$0,]H+
ps.getIndexes()得到分页索引的数组 O&BNhuW2
ps.getTotalCount()得到总结果数 " kp+1sG8
ps.getStartIndex()当前分页索引 }
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ps.getNextIndex()下一页索引 ?+Gc.lU
ps.getPreviousIndex()上一页索引 1<|\df.
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ^97u0K3$
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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 wHx@&Tp
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一下代码重构了。 oKyl2jg+,
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我把原本我的做法也提供出来供大家讨论吧: S
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首先,为了实现分页查询,我封装了一个Page类: %!P^se
java代码: D+4oV6}~
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/*Created on 2005-4-14*/ 10tlD<eYb
package org.flyware.util.page; 7x>\/l(
#/N;ScyUJT
/** t =LIkwD
* @author Joa .X1xpi%
* {ovt
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*/ b'AA*v,b
publicclass Page { /UWv}f
0
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/** imply if the page has previous page */ `L~gERW#
privateboolean hasPrePage; lZ,w#sqbY
3R|UbG`
/** imply if the page has next page */ n[[2<s*YJ
privateboolean hasNextPage; M=rH*w{^
N>V\
/** the number of every page */ @kstG3@
privateint everyPage; V2B@Lq"9`
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/** the total page number */ 9U]3B)h%m
privateint totalPage; r..&6-%:N
m!Y4+KTwD`
/** the number of current page */ 3A&:
c/
privateint currentPage; DXF>#2E^+
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/** the begin index of the records by the current .gQYN2#zb
aU\R!Y$/"
query */ f]sc[_n]
privateint beginIndex; \wR;N/tg
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/** The default constructor */ 3g79/w
public Page(){
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} R6cd;| fan
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/** construct the page by everyPage } *:H\GL
* @param everyPage tUGnp'r
* */ m'n<.1;1{j
public Page(int everyPage){ V$Zl]f$S
this.everyPage = everyPage; Kcu*Z
} F+<e9[
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/** The whole constructor */ 99GK6}~TGm
public Page(boolean hasPrePage, boolean hasNextPage, S1I# qb
GI5#{-)
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int everyPage, int totalPage, |S6L[Uo
int currentPage, int beginIndex){ :pJKZ2B,
this.hasPrePage = hasPrePage; T)#e=WcP]
this.hasNextPage = hasNextPage; b3 NEYn
this.everyPage = everyPage; >PS`;S!(
this.totalPage = totalPage; 0n/+X[%Ti
this.currentPage = currentPage; ;$Pjl8\
this.beginIndex = beginIndex; d~abWBgC`
} r91b]m3xL
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/** j&-<e7O=
* @return )NLjv=ql
* Returns the beginIndex. P.
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*/ Oh=E!
publicint getBeginIndex(){ *<ILSZ
return beginIndex; ?Gnx!3Q
} Ud:;kI%Vj
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/** U[O7}Nsb"
* @param beginIndex o_C]O"
* The beginIndex to set. (z.4er}o
*/ eWGaGRem
publicvoid setBeginIndex(int beginIndex){ ET0^_yk
this.beginIndex = beginIndex; AfT;IG%Gt
} ) :VF^"
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/** 5~FXy{ZIH
* @return #z#`EBXV$6
* Returns the currentPage. v"YaMbu
*/ Gd Vrl[
publicint getCurrentPage(){ YH,u*.I^/
return currentPage; g1{2E<b5
} rM0Idc.$&&
nV/;yl4e{
/** m;cgX#k5
* @param currentPage *@eZt*_
* The currentPage to set. yvCX
is
*/ \AOHZ r
publicvoid setCurrentPage(int currentPage){ \R[f< K%
this.currentPage = currentPage; ,1
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} K3^2;j1F Q
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/** DQ.; 2W
* @return 2-dEie/{'
* Returns the everyPage. ja&S^B^@
*/ /5Tp)h|
publicint getEveryPage(){ PiJ>gDx
return everyPage; \C kb:
} M@ =VIrX,m
_/z3QG{Ea^
/** Hrg -5_
* @param everyPage R4%}IT^%P
* The everyPage to set. )mu[ye"p
*/ BIxjY!!"
publicvoid setEveryPage(int everyPage){ LMRq.wxbbB
this.everyPage = everyPage; PUEEfq!%
} L2IY$+=M
p5Wz.n.<'
/** ?wVq5^ e
* @return wBz5_ OFVw
* Returns the hasNextPage. m't8\fo^w
*/ rm%MQmF
publicboolean getHasNextPage(){ 534DAhpD=.
return hasNextPage; ZC97Z sE
} cD'|zH]
8,L)=3m-
/** 2CRgOFR
* @param hasNextPage 7OD2/{]5
* The hasNextPage to set. &?*H`5#?G
*/ i#I7ncX
publicvoid setHasNextPage(boolean hasNextPage){ hQ}y(2A.XI
this.hasNextPage = hasNextPage; TG6E^3a P
} Qe;R3D=T;
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/** !'(QF9%Q
* @return -eFq^KP2
* Returns the hasPrePage. ebiOR1)sN
*/ R6`,}<A]@
publicboolean getHasPrePage(){ 4tlLh`-8
return hasPrePage; $bF3v=u`
} )sLXtV)nm6
lpnPd{kE
/** BM[jF=0
* @param hasPrePage o)+Uyl
* The hasPrePage to set. Q tl!f
*/ 'RpX&g
publicvoid setHasPrePage(boolean hasPrePage){ y eWB.M~X
this.hasPrePage = hasPrePage; zt2#6v
} H{g&yo
qa,i:T(w
/** #@:GLmD%
* @return Returns the totalPage. j4+kL4M@H
* xeW}`i5_w
*/ evlz R/
publicint getTotalPage(){ uF\ ;m.
return totalPage; XXy&1C
} m^KK
#Hw/`
2`pg0ciX (
/** MXs]3M
* @param totalPage I`q"
* The totalPage to set. 6]fz;\DgP
*/ .&rL>A2U
publicvoid setTotalPage(int totalPage){ N4u-tlA
this.totalPage = totalPage; h 6juX'V
} ;oWak`]f
C!^[d
} Y\j5{;V
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/=g$_m@yWI
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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 :|N(:W>=$Y
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个PageUtil,负责对Page对象进行构造: ]L_h3Xz\X
java代码: oT*qMLdn
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c}mWAZ=wF
/*Created on 2005-4-14*/ 1Wb_>`;
package org.flyware.util.page; h[oI/X
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@m
import org.apache.commons.logging.Log; jbTsrj"g
import org.apache.commons.logging.LogFactory; o,_R;'\E[a
fvr|<3ojo
/** sJ7ZE-v]h
* @author Joa CDT3&N1'R
* en-HX3'
*/ .NT9dX
publicclass PageUtil { -$o4WSd~
5?-@}PL!Y
privatestaticfinal Log logger = LogFactory.getLog {xCqz0
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(PageUtil.class); HBcL1wfS
~ ":}Rs
/** %Iv*u sXP
* Use the origin page to create a new page ,o sM|!,
* @param page DgKe!w$
* @param totalRecords 6Jd.Eg ~A7
* @return 17+2`@vJgM
*/ \pVWYx
publicstatic Page createPage(Page page, int yc.9CTxx
18o5Gs;yx
totalRecords){ 'L8B"5|>
return createPage(page.getEveryPage(), /7uAf{
a
G\
page.getCurrentPage(), totalRecords); 2)(ynrCe
} r;8X6C
q1,jDJglZ
/** XG01g3
* the basic page utils not including exception %OAvhutS
>%c7|\q[ R
handler >M^4p
* @param everyPage .{4U]a;[
* @param currentPage R3@luT]
* @param totalRecords VTJxVYE
* @return page Q$8K-5U%
*/ hv#|dI=kZR
publicstatic Page createPage(int everyPage, int HB,
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G$-[(eu-
currentPage, int totalRecords){ ;CLOZ{
everyPage = getEveryPage(everyPage); @aUQy;
currentPage = getCurrentPage(currentPage); E{xcu9
int beginIndex = getBeginIndex(everyPage, /eY}0q%
h9I vuv'
currentPage); v6KRE3:V
int totalPage = getTotalPage(everyPage, L<0eIw
s|IC;C|
totalRecords); Ms14]M[\
boolean hasNextPage = hasNextPage(currentPage, 4Bk9d\z
C(}N*e1
totalPage); w=QW8q?
boolean hasPrePage = hasPrePage(currentPage); KYR64[1
:Hq#co
returnnew Page(hasPrePage, hasNextPage, _7b' i6-
everyPage, totalPage, \&b1%Asyz
currentPage, P;
9{;
1i/&t[
beginIndex); `
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} l9#@4Os
4N8(WI"4S
privatestaticint getEveryPage(int everyPage){ N'~l,{
return everyPage == 0 ? 10 : everyPage; uc]`^,`2/
} B;c2gu
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privatestaticint getCurrentPage(int currentPage){ k%%0"+y#a
return currentPage == 0 ? 1 : currentPage; yhh\?qqy
} z~Is
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privatestaticint getBeginIndex(int everyPage, int $$e"[g
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currentPage){ ]4eIhj?
return(currentPage - 1) * everyPage; Eh&-b6:
} ~zhP[qA})
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privatestaticint getTotalPage(int everyPage, int #TPS?+(
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totalRecords){ Z~v-@
int totalPage = 0; jW;g{5X
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if(totalRecords % everyPage == 0) )<[)7`
totalPage = totalRecords / everyPage; [^0 S#,L
else pYz\GSd
totalPage = totalRecords / everyPage + 1 ; N;R I
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return totalPage; 9y?)Ga
} odhcU5
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privatestaticboolean hasPrePage(int currentPage){ &NH[b1NMr
return currentPage == 1 ? false : true; u#nM_UJe
} uUJH^pW
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privatestaticboolean hasNextPage(int currentPage, nR8r$2B+t
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int totalPage){ x};sti R
return currentPage == totalPage || totalPage == qyL!>kZr@
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0 ? false : true; Z7dyPR
} Q/`W[Et
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} RX?y}BDo0
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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。 7'.]fs:
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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 Iad&Z8E
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做法如下: N2.Ym;^
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 xjh(;S'
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的信息,和一个结果集List: /~3kkM(Ty
java代码: gN.n_!
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/*Created on 2005-6-13*/ ffR<G&"n~b
package com.adt.bo; pvhN.z
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import java.util.List; s'/ZtH6>C
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import org.flyware.util.page.Page; (?1/\r
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/** x9\]C'*sO
* @author Joa h^'+y1
*/ @ \*Zq
publicclass Result { ?*&5`Xh
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private Page page; 1F R
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private List content; `JcWH_[
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/** t8.^Y TI
* The default constructor C(n_*8{
*/ cUr5x8<W).
public Result(){ _ ( $U\FW
super(); 7{p6&xXx
} ~p
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/** y.gjs<y
* The constructor using fields bMGXx>x
* yH0vESgv
* @param page S]?I7_
* @param content gwDVWhq
*/ jD?*sd
public Result(Page page, List content){ {R?VB!dR
this.page = page; )i<Qg.@MX
this.content = content; %7
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*
} byPqPSY
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/** 4VhKV JX
* @return Returns the content. kOQ!]-;
*/ nw0Tg= P
publicList getContent(){ V W( +sSQ
return content; U% OlYP$g
} Q-KBQc
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/** ^bECX<,H
* @return Returns the page. '#>(JN5\
*/ uQg&