Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 OJ?U."Lxm$
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 $&Lw 2 c0
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 .VXadgM
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分页支持类: R+r;V ]-/
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java代码: 9s4>hw@u
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package com.javaeye.common.util; -J":'xCP!
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import java.util.List; bt=z6*C>A
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publicclass PaginationSupport { Qa#Em1co
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publicfinalstaticint PAGESIZE = 30; `gvd8^
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privateint pageSize = PAGESIZE; s{uSU1lQn
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privateList items; JuDadIrd{
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privateint totalCount; EG!Nsb^,
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privateint[] indexes = newint[0]; tS3!cO\
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privateint startIndex = 0; n#PXMD*
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public PaginationSupport(List items, int yk0^m/=C(
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totalCount){ '$h0l-mQ
setPageSize(PAGESIZE); q|_Cj]{
setTotalCount(totalCount); o0kKf+[
setItems(items); +2#pP
setStartIndex(0); &ox5eX(
} SoHw9FtS
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public PaginationSupport(List items, int <YAs0
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totalCount, int startIndex){ ,a3M*}Y~3
setPageSize(PAGESIZE); @NYlVk2
setTotalCount(totalCount); .h-k*F0Ga)
setItems(items); goZw![4l
setStartIndex(startIndex); >p29|TFbV
} ]#;u]
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public PaginationSupport(List items, int N)EJP~0
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totalCount, int pageSize, int startIndex){ PTpGZ2FZ
setPageSize(pageSize); ~pw%p77)
setTotalCount(totalCount); {#N,&?[
setItems(items); H<Zs2DP`
setStartIndex(startIndex); r!c7{6N
} GrA}T` ]
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publicList getItems(){ %'MR;hQsd8
return items; .*Axr\x3
} wKE}BO >
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publicvoid setItems(List items){ eC='[W<a.
this.items = items; $-uMWJ)l
} &4m;9<8\
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publicint getPageSize(){ rT'<6]`
return pageSize; Ubv_a
} \|7Y"WEQ
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publicvoid setPageSize(int pageSize){ Y'?{yx{
this.pageSize = pageSize; K7},X01^
} ub-vtRpm
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publicint getTotalCount(){ =c#;c+a
return totalCount; )2?A|f8
} vPsf{[Kr
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publicvoid setTotalCount(int totalCount){ g7r0U6Y
if(totalCount > 0){ b`^mpB*6R
this.totalCount = totalCount; |DUOyQ
int count = totalCount / Es&'c1$^s
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pageSize; 9R N ge;*
if(totalCount % pageSize > 0) KV|ywcGhT
count++; xHaoSs*C9
indexes = newint[count]; yb-/_{Y
for(int i = 0; i < count; i++){ (!koz'f
indexes = pageSize * `cqZ;(^
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i; {%8=qJ3@
} E#`JH
}else{ {\5-b:#_
this.totalCount = 0; IWnyqt(k
} k(wJ6pc
} Dl_SEf6b
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publicint[] getIndexes(){ s/OXZ<C|
return indexes; *Edr\P
} 9S{?@*V
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publicvoid setIndexes(int[] indexes){ A5YS
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this.indexes = indexes; <Q?_],ip
} fVxRK\a\\
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publicint getStartIndex(){ =ve, !
return startIndex; C<hb{$@
} \2AXW@xE
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publicvoid setStartIndex(int startIndex){ `bEum3l\6]
if(totalCount <= 0) -P$E)5?^
this.startIndex = 0; Yd$64d7,h
elseif(startIndex >= totalCount) DZ&AwF
this.startIndex = indexes nXxSv~r
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[indexes.length - 1]; z<s4-GJ)?
elseif(startIndex < 0) vQL)I
this.startIndex = 0; #mbl4a
else{ !'
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this.startIndex = indexes ybVdWOqv
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[startIndex / pageSize]; bn8?-
} ` L?9-)m<f
} (1}"I
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publicint getNextIndex(){ {y7,n
int nextIndex = getStartIndex() + ii]'XBSVd
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pageSize; p>
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if(nextIndex >= totalCount) {bPcr hB
return getStartIndex(); \ /6m
else Ia>>b #h
return nextIndex; t+BLO<
} JulxFjC
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publicint getPreviousIndex(){ Abf=b<bu
int previousIndex = getStartIndex() - a3oSSkT
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pageSize; {>=#7e-]
if(previousIndex < 0) c}g:vh
return0; Is !DiB
else xn)r6
return previousIndex; &_y+hV{
} [EV}P&U
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} R7!^ M
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抽象业务类 hy|X(m
java代码: 7&9'=G
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/** `)R@\@jt
* Created on 2005-7-12 )SYZ*=ezl.
*/ ;j/-ndd&&
package com.javaeye.common.business; jZ>'q/
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import java.io.Serializable; ';?b99
import java.util.List; R0*+GIRA(
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import org.hibernate.Criteria; ]]Da/^K=Z
import org.hibernate.HibernateException; eX>X=Ku
import org.hibernate.Session; JSQ*8wDcl
import org.hibernate.criterion.DetachedCriteria; 84*Fal~Som
import org.hibernate.criterion.Projections; tr\Vr;zd
import Wy%F
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org.springframework.orm.hibernate3.HibernateCallback; g$*VA} s
import =7`0hS<@F
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org.springframework.orm.hibernate3.support.HibernateDaoS Cz_chK4
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upport; `-N&cc
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import com.javaeye.common.util.PaginationSupport; WwDxZ>9jw
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public abstract class AbstractManager extends jsvD[ \P
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HibernateDaoSupport { E$[\Fk}S
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privateboolean cacheQueries = false; %.R_[.W
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privateString queryCacheRegion; eMvb*X6
; (+r)r_
publicvoid setCacheQueries(boolean b\w88=|
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cacheQueries){ [y T4n.f
this.cacheQueries = cacheQueries; bMD'teJ
} VQvl,'z
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publicvoid setQueryCacheRegion(String 8D:{05
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queryCacheRegion){ A2"xCJ0`
this.queryCacheRegion = 0ZV)Y<DJ
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queryCacheRegion; 5Ffz^;i
} Al`[Iu&
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publicvoid save(finalObject entity){ %zyMWC
getHibernateTemplate().save(entity); Mf&W<n^j
} <8At= U
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publicvoid persist(finalObject entity){ >1tGQ
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getHibernateTemplate().save(entity); 3Fn26Rij
} 7
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publicvoid update(finalObject entity){ y=\jQ6Fc
getHibernateTemplate().update(entity);
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} BifA&o%
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publicvoid delete(finalObject entity){ %1]2+_6
getHibernateTemplate().delete(entity); <5(8LMF
} .>?["e #,
= sIR[V'(
publicObject load(finalClass entity, 9hT^Y,c0
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finalSerializable id){ IR%a+;Xs
return getHibernateTemplate().load 9kP!O_
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(entity, id); 9VN@M
} bYdC.AE
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publicObject get(finalClass entity, KF'H|)!K
);z}T0C
finalSerializable id){ %MP s}B
return getHibernateTemplate().get ;?2vW8{p<
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(entity, id); J6 [x(T
} Xt=&
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publicList findAll(finalClass entity){ J5Fg]O*
return getHibernateTemplate().find("from 0 $e;#}
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" + entity.getName()); Ai->,<Ig]
} ;^DUtr
;
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publicList findByNamedQuery(finalString |-_5ouN.
*!9/`zW
namedQuery){ :/vB,JC
return getHibernateTemplate U&3*c+B4
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().findByNamedQuery(namedQuery); RC (v#G
} AD?DIE(v
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publicList findByNamedQuery(finalString query, 6ddkUPTF
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finalObject parameter){ m4Wn$Z
return getHibernateTemplate E}@8sY L
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().findByNamedQuery(query, parameter); :
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} faO8
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publicList findByNamedQuery(finalString query, mZ;yk(
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finalObject[] parameters){
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return getHibernateTemplate 38q@4U=aiw
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().findByNamedQuery(query, parameters); j|`{
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} -;P<Q`{I
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publicList find(finalString query){ Xb^\{s?b
return getHibernateTemplate().find BE"nyTQ
k) v[/#I
(query); Msd!4TrBJ
} m]-8?B1`Y
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publicList find(finalString query, finalObject l IFt/
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parameter){ Bd
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return getHibernateTemplate().find i9!Urq-
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(query, parameter); R^B2J+O
} =(n'#mV
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public PaginationSupport findPageByCriteria mzT} C&hfP
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(final DetachedCriteria detachedCriteria){ "{x~j\<
return findPageByCriteria K%pmE?%,8
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); q5vs;,_
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} /2@%:b)
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public PaginationSupport findPageByCriteria ;n;^f&;sJ
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(final DetachedCriteria detachedCriteria, finalint d(@A
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startIndex){ 9wq%Fnt
return findPageByCriteria ZM#WdP
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(detachedCriteria, PaginationSupport.PAGESIZE, %C3cdy_c
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startIndex); m|]^f;7z
} D+SpSO7yg
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public PaginationSupport findPageByCriteria \OU+Kl<
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(final DetachedCriteria detachedCriteria, finalint &16bZw
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pageSize,
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finalint startIndex){ *[SsvlFt
return(PaginationSupport) Un/fP1
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getHibernateTemplate().execute(new HibernateCallback(){ Iv<9})2K
publicObject doInHibernate z;/'OJ[.
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(Session session)throws HibernateException { 4 P;O8KA5y
Criteria criteria = b{I`$E<[
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detachedCriteria.getExecutableCriteria(session); 1}BNG ,n
int totalCount = 4jz]c"p-
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((Integer) criteria.setProjection(Projections.rowCount epbp9[`
=a!6EkX
*
()).uniqueResult()).intValue(); pMquu&Td
criteria.setProjection `e9uSF:9C
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(null); |f:d72{Qr
List items = q8h{-^"
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criteria.setFirstResult(startIndex).setMaxResults ?8, N4T0)
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(pageSize).list(); Dgm%Ng
PaginationSupport ps = 84!4Vz^
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new PaginationSupport(items, totalCount, pageSize, AY;+Ws
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startIndex); O<h#|g1
return ps; `az`?`i7
} cA%U
}, true); Zd(d]M_x
} ^d9raYE`'
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public List findAllByCriteria(final LgNNtZ&F
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DetachedCriteria detachedCriteria){ "r
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return(List) getHibernateTemplate 0w['jh|,
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().execute(new HibernateCallback(){ 4LjSDgA
publicObject doInHibernate oPy zk7{
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(Session session)throws HibernateException { \Ep/'Tj&
Criteria criteria =
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detachedCriteria.getExecutableCriteria(session); \z`d}\3(R
return criteria.list(); b(q&}60
} J\so8uT:
}, true); qE72(#:R*
} -HsBV>C
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public int getCountByCriteria(final <PN;D#2bh
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DetachedCriteria detachedCriteria){ 4) iEj
Integer count = (Integer) ijqdZ+
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getHibernateTemplate().execute(new HibernateCallback(){ i`aG
publicObject doInHibernate YB{E=\~
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(Session session)throws HibernateException { JX)z<Dz$
Criteria criteria = Cj1UD;
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detachedCriteria.getExecutableCriteria(session); $l;tP
return DiQkT R
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criteria.setProjection(Projections.rowCount W79A4l<
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()).uniqueResult(); ;]M67ma7C
} 'D"K`Vw
}, true); R[9PFMn
return count.intValue(); (MoTG^MrBY
} '%!M>rY,
} =Xjuz:9D~
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用户在web层构造查询条件detachedCriteria,和可选的 x\hn;i<
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 WQLL[{mhS
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PaginationSupport的实例ps。 0*;9CH=BE
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ps.getItems()得到已分页好的结果集 f76|
ps.getIndexes()得到分页索引的数组 6>BDA?
ps.getTotalCount()得到总结果数 kw^Dp[8X
ps.getStartIndex()当前分页索引 @!a]qAt
ps.getNextIndex()下一页索引 T7,Gf({
ps.getPreviousIndex()上一页索引 D'[P,v;Q
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ]<;i}n|
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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 Pv-V7`{
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一下代码重构了。 DET!br'z5
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我把原本我的做法也提供出来供大家讨论吧: !+45=d 5
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首先,为了实现分页查询,我封装了一个Page类: YTjuSV
java代码: CAFE}|
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/*Created on 2005-4-14*/ YV3TxvXMR
package org.flyware.util.page; h,'mN\6t
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/** h
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* @author Joa &8_f'+i0
* d+m6-4[_k
*/ VVQ74b
publicclass Page { Y\g90
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/** imply if the page has previous page */ p-yOiG8b}
privateboolean hasPrePage; n|mJE,N
!Ir1qt8T
/** imply if the page has next page */ enbN0
privateboolean hasNextPage; (LT\
IJSM
;vv!qBl|@
/** the number of every page */ \,%o>M'
privateint everyPage; }u3H4S<o
L >Ez-
/** the total page number */ "'}v 0*[
privateint totalPage; f0mH|tI`
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/** the number of current page */ ;+ Co!L
privateint currentPage; ^0-e,d
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/** the begin index of the records by the current emkMR{MY
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query */ =wlm
privateint beginIndex; o9T@uWh+
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/** The default constructor */ cJHABdK-
public Page(){ }* B qi7E>
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} / 8WpX
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/** construct the page by everyPage C{`^9J-
* @param everyPage 2iR:*}5
* */ tJh3$K\
public Page(int everyPage){ v/aPiFlw
this.everyPage = everyPage; KT
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} *m| t=9E
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/** The whole constructor */ |>IUtUg\
public Page(boolean hasPrePage, boolean hasNextPage, 0?6If+AC
:?$Sb8OuIL
){:q;E]^fB
int everyPage, int totalPage, /H%<oAjp6
int currentPage, int beginIndex){ 0V>ESyae5
this.hasPrePage = hasPrePage; a* W_fxb
this.hasNextPage = hasNextPage; %<=w [*i
this.everyPage = everyPage; .o\;,l2
this.totalPage = totalPage; \`P2Yq
this.currentPage = currentPage; clq~ ;hx
this.beginIndex = beginIndex; DYT@BiW{
} M}=s3[d(,
#7-kL7 MK]
/** \8>
* @return 0\EpH[m}-
* Returns the beginIndex. bRK CY6
*/ wuBlFUSg
publicint getBeginIndex(){ z<yNG/M1>U
return beginIndex; e>?_)B4
} v9t47>V
^)9MzD^_nV
/** "RV`L[(P*k
* @param beginIndex }&Wp3EWw
* The beginIndex to set. |8DH4*y!
*/ Z^'?|qFj!
publicvoid setBeginIndex(int beginIndex){ )KaLSL>
this.beginIndex = beginIndex; wVvqw/j*f
} P7'oXtW{o
k9^+9P^L
/** _C< 6349w
* @return QD.zU/F~>
* Returns the currentPage. dN]Zs9]
*/ .])>A')r
publicint getCurrentPage(){ z`emKFbv
return currentPage; zp7V\W;
&
} Sc;iAi
(
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/** ,2 zt.aqB
* @param currentPage <&qpl0U)Y
* The currentPage to set. laUu"cS
*/ 3bbp>7V!
publicvoid setCurrentPage(int currentPage){ ;Pol#0_(
this.currentPage = currentPage; E3~,+68U
} N_u&3CG
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/** %sO Wg.0_
* @return 5u2{n rc
* Returns the everyPage. XKz;o^1a^
*/ 1A7 %0/K-]
publicint getEveryPage(){ lv<iJH\
return everyPage; .-SDo"K.h
} g
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/** F[>7z3I
* @param everyPage
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* The everyPage to set. :r1;}hIA9
*/ u-AWJc+F .
publicvoid setEveryPage(int everyPage){ V,>+G6e
this.everyPage = everyPage; *'UhlFed
} 0K=Qf69Y
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/** W4)kkJ
* @return 0Y2\n-`z
* Returns the hasNextPage. g\ErJ+i
*/ ^=eq .(>
publicboolean getHasNextPage(){ LYd}w(}
return hasNextPage; xN#bzma
} vOos*&
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/** G{@C"H[$<
* @param hasNextPage :7 qqjs
* The hasNextPage to set. Jt##rVN
*/ zq,iLoY[R
publicvoid setHasNextPage(boolean hasNextPage){ ayV6m
this.hasNextPage = hasNextPage; >;&Gz-lm
} |HrM_h<X
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/** 6OfdD.y
* @return
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* Returns the hasPrePage. u9TzZ
*/ HG2N-<$
publicboolean getHasPrePage(){ -'I _*fu
return hasPrePage; k4S} #!
} o .l;:
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/** uz ]E_&2
* @param hasPrePage :|Z$3q
* The hasPrePage to set. .
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*/ g d z
publicvoid setHasPrePage(boolean hasPrePage){ aRbx
this.hasPrePage = hasPrePage; lkV6qIj
} ,VPbUo@
+p13xc?#j
/** 'I&|1I^
* @return Returns the totalPage. ,`;jvY~Ec
* ./#e1m?.
*/ 'dkXYtKCB
publicint getTotalPage(){ #2h+dk$1
return totalPage; y)6,0K {k
} NA+&jV
XR|"dbZW.0
/** 3rxo,pX94
* @param totalPage u FMIY(vB
* The totalPage to set. DC&A1I&
*/ /@Ez" ?V2
publicvoid setTotalPage(int totalPage){ >Z *iE"9"
this.totalPage = totalPage; b& V`<'{
} 3DH.4@7P
p ss6Oz8
} _)Qy4[S=d
,
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bFSlf5*H
pFpZbU^
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 (Up'$J}
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个PageUtil,负责对Page对象进行构造: Ejq=*UOP
java代码: lj)f4zu
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2A*/C7
/*Created on 2005-4-14*/ G-arnu)
package org.flyware.util.page; (B&h;U$HAH
$'^&\U~?
import org.apache.commons.logging.Log; 3@G;'|z
import org.apache.commons.logging.LogFactory; DR6]-j!FK
qh-[L
/** ):krJ+-/y
* @author Joa cqEHYJ;B
* Xem 05%,
*/ 6_*!|g
publicclass PageUtil { Sr&T[ex,.
N=#4L$@-
privatestaticfinal Log logger = LogFactory.getLog Id%_{),HX
jPnO@H1
(PageUtil.class); z!:'V]
y?>#t^
/** 27>a#vCT
* Use the origin page to create a new page co/7l sW
* @param page =N_,l'U\^
* @param totalRecords 9RxO7K
* @return *xcP`
*/ ;W0]66&
publicstatic Page createPage(Page page, int +vz`go
2/@D7>F&g
totalRecords){ >\ZR*CS
return createPage(page.getEveryPage(), R uLvG+
}kE87x'
page.getCurrentPage(), totalRecords); J='W+=N
} 0N{+y}/G
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/** Ib1e#M3
* the basic page utils not including exception O6iCZ
~s#e,Kav"
handler azo0{`S?
* @param everyPage < A?<N?%o
* @param currentPage snYr9O[E6
* @param totalRecords Q2eXK[?*
* @return page |) Pi6Y
*/ t8&q9$
publicstatic Page createPage(int everyPage, int Jf)3< ~G
: tM?%=Q
currentPage, int totalRecords){ b{RqwV5P
everyPage = getEveryPage(everyPage); fYBH)E
currentPage = getCurrentPage(currentPage); ~GG?GB
int beginIndex = getBeginIndex(everyPage, Gy!P,a)z
55-D\n<
currentPage); 9cQ_mgch
int totalPage = getTotalPage(everyPage, G;TsMq
wVqd$nsY"
totalRecords); :
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boolean hasNextPage = hasNextPage(currentPage, bC~~5Cm
Q2/.6O8
totalPage); JDv-O&]
boolean hasPrePage = hasPrePage(currentPage); ?+r!z
$b>}C= gt
returnnew Page(hasPrePage, hasNextPage, HM&1yubh#
everyPage, totalPage, MdC<4^|
currentPage, K;U39ofW
/APcL5:=
beginIndex); wGJjA=C
} knT.l"
5j eO"jB
privatestaticint getEveryPage(int everyPage){ ]` ]g@v
return everyPage == 0 ? 10 : everyPage; =Ikg.jYq&F
} kq-6HDR
Km3&N
privatestaticint getCurrentPage(int currentPage){ DA"}A`HfI
return currentPage == 0 ? 1 : currentPage; @T&t.|`
} -[R!O'N9
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privatestaticint getBeginIndex(int everyPage, int Y-p<qL|_
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currentPage){ +;q.Y?
return(currentPage - 1) * everyPage; H9`
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} xd8
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privatestaticint getTotalPage(int everyPage, int \t3qS
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*
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totalRecords){ o>c^aRZ{
int totalPage = 0; #SkX@sl@
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if(totalRecords % everyPage == 0) ^Y04qeRd
totalPage = totalRecords / everyPage; Ht[{ryTxu
else :?CQuEv-
totalPage = totalRecords / everyPage + 1 ; ?_q+&)4-o
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return totalPage; ~]WVG@-
} ,P6=~q3k
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privatestaticboolean hasPrePage(int currentPage){ V5"HwN+`
return currentPage == 1 ? false : true; dqe7s Zl!
} X=~V6m
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privatestaticboolean hasNextPage(int currentPage, [VSU"AJY
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int totalPage){ iOqk*EL_r\
return currentPage == totalPage || totalPage == 7Kf}O6nE
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0 ? false : true; f9TV%fG?
} Cca0](R*&
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} O~@fXMthh
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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。 $%2H6Eg0
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 #cKqnk
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做法如下: fgF;&(b
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 \cuS>G
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的信息,和一个结果集List: *'ZN:5%H
java代码: x5Zrz<Y$w
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/*Created on 2005-6-13*/ 2KI!af[I
package com.adt.bo; ]hTb@.
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import java.util.List; RL}KAGK
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import org.flyware.util.page.Page; 2t1I3yA'{z
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/** Lz4ehWntO
* @author Joa Bw<rp-
*/ ZR3nK0
publicclass Result { 7}B
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private Page page;
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private List content; z?ucIsbR
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/** @q8an
* The default constructor ,&]MOe4@>
*/ '2^
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public Result(){ w+AuMc
super(); Hs?zq
} c^.l2Q!
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/** N$ alUx*
* The constructor using fields O/OiQ^T
* py<_HyJ
* @param page \2X$C#8E
* @param content F 3RB
*/ s&
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public Result(Page page, List content){ =mt?Cn}
this.page = page;
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