Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 UGgo;e
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 dV'^K%#
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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 \Zx&J.D
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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 F]>+pU
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分页支持类: ed_+bCNy
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java代码: Lr6C@pI
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package com.javaeye.common.util; !?+0O]`}
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import java.util.List; `Eu,SvkF w
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publicclass PaginationSupport { %0}}Qt
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publicfinalstaticint PAGESIZE = 30; d=uGB"
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privateint pageSize = PAGESIZE; 0_+
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privateList items; (0`w.n
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privateint totalCount; 7w8UnPuM
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privateint[] indexes = newint[0]; D2gyn-]\
;
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privateint startIndex = 0; *f>\X[wN
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public PaginationSupport(List items, int Wc!]X.|9*
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totalCount){ $G }9iV7
setPageSize(PAGESIZE); k4u/vn`&r
setTotalCount(totalCount); P{_%p<:V
setItems(items); m8R=wb
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setStartIndex(0); :?FHqfN?_
} Ij =NcP
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public PaginationSupport(List items, int `VUJW]wGu
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totalCount, int startIndex){ .7 LQ l?
setPageSize(PAGESIZE); .\ya
setTotalCount(totalCount); EEK!'[<,sE
setItems(items); g"m9[R=]6
setStartIndex(startIndex); .sM,U
} dKU:\y
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public PaginationSupport(List items, int -vY5h%7kf
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totalCount, int pageSize, int startIndex){ =>evkaj
setPageSize(pageSize); In1n.oRFn^
setTotalCount(totalCount); 3RvDX p
setItems(items); +TaxH;
setStartIndex(startIndex); Qo^(r$BD
} ^?sP[;8S!
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publicList getItems(){ *mJ#|3I<
return items; 5$Kj#9g-#
} CxJ3u
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publicvoid setItems(List items){ .QZjJ9pvK
this.items = items; 9Oq(` 4
} IvY3iRq6
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publicint getPageSize(){ EU|IzUjFj|
return pageSize; 5p:BHw;%;
} JN` $Fq+
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publicvoid setPageSize(int pageSize){ -Q
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this.pageSize = pageSize; @H4]Gp ]
} 9\WtcLx
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publicint getTotalCount(){ vyJ8"
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return totalCount; X;UEq]kcmn
} G/(,,T}eG
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publicvoid setTotalCount(int totalCount){ _Z9d.-
if(totalCount > 0){ j3`YaWw
this.totalCount = totalCount; x0ipk}
int count = totalCount / wuYak"KX
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pageSize; y {Bajil
if(totalCount % pageSize > 0) E0fMFG^P
count++; =SeQ- H#
indexes = newint[count]; 9*K-d'm
for(int i = 0; i < count; i++){ An0N'yo"Z
indexes = pageSize * Y%0rji
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} ;]m;p,$
}else{ r4K9W90
this.totalCount = 0; F!u)8>s+z{
} )8#-IXxp
} *n&Sd~Mg
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publicint[] getIndexes(){ &I8DK).M+
return indexes; )uo".n|n~B
} Y,}h{*9Kd
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publicvoid setIndexes(int[] indexes){ u pUJF`3
this.indexes = indexes; pt3)yj&XE
} .$W}
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publicint getStartIndex(){ KA{QGaZ/
return startIndex; ]S@T|08b
} \ctzv``/n
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publicvoid setStartIndex(int startIndex){ h?OSmzRLd
if(totalCount <= 0) 3gVU#T[[
this.startIndex = 0; N}7b^0k
elseif(startIndex >= totalCount)
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this.startIndex = indexes <D)@;A
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[indexes.length - 1]; \#w8~+`Gq
elseif(startIndex < 0) u1u;aG
this.startIndex = 0; !]A/ID0K
else{ W?E,"z
this.startIndex = indexes bf2n%-&9g
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[startIndex / pageSize]; 8$47Y2r@
} z2,NWmP|w
} K8BlEF`
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publicint getNextIndex(){ :R:@V#Y
int nextIndex = getStartIndex() + P{`fav
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pageSize; t5K#nRd Z:
if(nextIndex >= totalCount) 2h*aWBLk
return getStartIndex(); ,98 F
else G,Eh8HboK
return nextIndex; 4Y1^ U{A+
} DaHbOs_<
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publicint getPreviousIndex(){ <im}R9eJ1
int previousIndex = getStartIndex() - %_p]6doF
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pageSize; P~:^bU^F7
if(previousIndex < 0) $J)`Ru6.
return0; yW7>5r
else G^SJhdO(Q
return previousIndex; hH;i_("i(h
} 9yTkZ`M28
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} f8r7SFwUv
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抽象业务类 &LB`
java代码: xpuTh"ED
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/** 5i'?oXL
* Created on 2005-7-12 46 \!W(O~y
*/ 9X33{
package com.javaeye.common.business; 0Db=/sJ>
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import java.io.Serializable; !e
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import java.util.List;
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import org.hibernate.Criteria; HP<a'| r
import org.hibernate.HibernateException; p*@t$0i
import org.hibernate.Session; -T+'3</T
import org.hibernate.criterion.DetachedCriteria; yn(bW\
import org.hibernate.criterion.Projections; 7u:kR;wk
import 3N2d@R
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org.springframework.orm.hibernate3.HibernateCallback; ta x:9j|~
import ).e}.Z6[i`
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org.springframework.orm.hibernate3.support.HibernateDaoS (47la$CR
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upport; i=P}i8,^=
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import com.javaeye.common.util.PaginationSupport; /f+BeQ3#/
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public abstract class AbstractManager extends {36N=A
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HibernateDaoSupport { akCCpnX_d
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privateboolean cacheQueries = false; F1M:"-bda
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privateString queryCacheRegion; Q6
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publicvoid setCacheQueries(boolean TpYh)=;k
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cacheQueries){ 4mX?PKvbn
this.cacheQueries = cacheQueries; 9GTp};Kg
} %AWc`D
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publicvoid setQueryCacheRegion(String _nX8f
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queryCacheRegion){ @+y,E-YTdV
this.queryCacheRegion = 0&2`)W?9
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queryCacheRegion; uNw9g<g:V[
} >XM]UdP
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publicvoid save(finalObject entity){ =1
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getHibernateTemplate().save(entity); PQh s^D
} Jm< uE]9
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publicvoid persist(finalObject entity){ 7~k=t!gTY
getHibernateTemplate().save(entity); |pq9i)e&
} 0bIgOLP
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publicvoid update(finalObject entity){ M1*bT@6
getHibernateTemplate().update(entity); cKoW5e|u
} MQ0rln?
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publicvoid delete(finalObject entity){ BIe:7cR%
getHibernateTemplate().delete(entity); 'ShK7j$
} ]bpgsW:Xu
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publicObject load(finalClass entity, (-&d0a9N
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finalSerializable id){ <l5m\A
return getHibernateTemplate().load %yk_(3a
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(entity, id); 6f
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} ?N!kYTR%}
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publicObject get(finalClass entity, K(d+t\ca
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finalSerializable id){ jh`[Y7RJO
return getHibernateTemplate().get ~{vB2
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(entity, id); ^M;#x$Y?
} _5x]BH6f
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publicList findAll(finalClass entity){ +"=ydF.9
return getHibernateTemplate().find("from 7\R"RH-
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" + entity.getName()); EUQtl_h/H
} RgQs`aI
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publicList findByNamedQuery(finalString :XG~AR/
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namedQuery){ >TBXT+
return getHibernateTemplate C_8_sbZ/
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().findByNamedQuery(namedQuery); Y#~A":A
} nbf/WOCk
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publicList findByNamedQuery(finalString query, ?2dI8bG
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finalObject parameter){ V %D1Q}X
return getHibernateTemplate
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().findByNamedQuery(query, parameter); NVsaV;u
} !U1
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publicList findByNamedQuery(finalString query, N)R5#JX
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finalObject[] parameters){ ubOXEkZ8N
return getHibernateTemplate >][D"
} e+`Kxy
().findByNamedQuery(query, parameters); OHsA]7S
} JTm'fo[
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publicList find(finalString query){ WulyMcJ
return getHibernateTemplate().find QeuM',6R
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(query); ?6`B;_m
} 4"(rZWv
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publicList find(finalString query, finalObject [WG\wj.
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parameter){ ~"SQwE|
return getHibernateTemplate().find |l+5E
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(query, parameter); h@G~'\8t
} /(51\RYkir
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public PaginationSupport findPageByCriteria 7H< IO`
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(final DetachedCriteria detachedCriteria){ 5:f!EMb
return findPageByCriteria /]!2k9u\
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); EGQgrwY5
} ob;|%_
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public PaginationSupport findPageByCriteria UgS`{&b36
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(final DetachedCriteria detachedCriteria, finalint rpm \!O
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startIndex){ Q'Osw"
return findPageByCriteria k)S1Z s~G
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(detachedCriteria, PaginationSupport.PAGESIZE, _r{H)}9
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startIndex); Jl`^`Yv
} $$1t4=Pz
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public PaginationSupport findPageByCriteria YxJQ^D`
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(final DetachedCriteria detachedCriteria, finalint j2_j5Hgo
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finalint startIndex){
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return(PaginationSupport) kP&I}RY
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getHibernateTemplate().execute(new HibernateCallback(){ aM;SE9/U
publicObject doInHibernate <Q9l'u]3$c
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(Session session)throws HibernateException { \j`0f=z_
Criteria criteria = $ItmYj.m
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detachedCriteria.getExecutableCriteria(session); P|$n
int totalCount = l1DJ<I2
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((Integer) criteria.setProjection(Projections.rowCount :
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()).uniqueResult()).intValue(); 4@{cK|
criteria.setProjection rC^5Z
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(null); =6Ok4Z
List items = Jq&Hz$L|
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criteria.setFirstResult(startIndex).setMaxResults ?pW1}:z
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(pageSize).list(); *HR
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PaginationSupport ps = -a)1L'R
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new PaginationSupport(items, totalCount, pageSize, Ur
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startIndex); LVB wWlJ
return ps;
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} #MA6eE'R
}, true); ~-A"j\gi"
} (NLw#)?
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public List findAllByCriteria(final =;0-t\w!
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DetachedCriteria detachedCriteria){ _gqqPny4$
return(List) getHibernateTemplate MT~^wI0a
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().execute(new HibernateCallback(){ #]jl{K\f#X
publicObject doInHibernate ~6t!)QATnp
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(Session session)throws HibernateException { -orRmn6}
Criteria criteria = `#ruZM066
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detachedCriteria.getExecutableCriteria(session); uM`i!7}
return criteria.list(); P_A@`eU0
} N4+Cg t(
}, true); v
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} H}kZ;8
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public int getCountByCriteria(final dB_0B.
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DetachedCriteria detachedCriteria){ zfKO)Itd
Integer count = (Integer) &K0b3AWc
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getHibernateTemplate().execute(new HibernateCallback(){ P'qBqx[
publicObject doInHibernate jvB[bS`<H
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(Session session)throws HibernateException { YYn8!FIe
Criteria criteria = p Run5 )7
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detachedCriteria.getExecutableCriteria(session); "HJ^>%ia
return u$R5Q{H_
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criteria.setProjection(Projections.rowCount B$2b=\
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()).uniqueResult(); -E?:W`!
} F~6]II
}, true); U/enq,-F^
return count.intValue(); CnB[ImMs(A
} T]wI)
} ,7j8+p|},
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用户在web层构造查询条件detachedCriteria,和可选的 A6=Z2i0w>X
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 +H3~Infr4f
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PaginationSupport的实例ps。 z)C}}NH*!@
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ps.getItems()得到已分页好的结果集 D Yf2V6'
ps.getIndexes()得到分页索引的数组 iXm&\.%
ps.getTotalCount()得到总结果数 16/ V5
ps.getStartIndex()当前分页索引 ?IAu,s*u
ps.getNextIndex()下一页索引 /= ;,lC
ps.getPreviousIndex()上一页索引 .rk5u4yK
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 t}R!i-D|HB
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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 ^)9/Wz _x
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一下代码重构了。 aaU4Jl?L
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我把原本我的做法也提供出来供大家讨论吧: T@ESMPeU:X
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首先,为了实现分页查询,我封装了一个Page类: >!1]G"U
java代码: m~Pk]~j
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/*Created on 2005-4-14*/ u;9iuc`*
package org.flyware.util.page; R8[VD iM6E
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/** K{_~W yRF
* @author Joa YMu#<ZG
* Kq")|9=d
*/ C2R"96M7q
publicclass Page { !X7z y9
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/** imply if the page has previous page */ I7Kgi3
privateboolean hasPrePage; g"sb0d9
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/** imply if the page has next page */ &]a(5
privateboolean hasNextPage; s;P _LaIp)
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/** the number of every page */ 8*8Y\"
privateint everyPage; TkTGYh
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/** the total page number */ -}TP)/!,*
privateint totalPage; {G=> WAXo
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/** the number of current page */ fV4eGIR&
privateint currentPage; 0>j0L8#^p
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/** the begin index of the records by the current 4;~xRg;u&*
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query */ 4?@5JpC9VA
privateint beginIndex; )Mq4p'*A[
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/** The default constructor */ ]z7pa^
public Page(){ t@lTA>;U@
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} MA tF,
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/** construct the page by everyPage b/.EA'/
* @param everyPage }c8e t'HYf
* */ *9KT@"v
public Page(int everyPage){ te;bn4~
this.everyPage = everyPage; ~yN>9f U
} nUq@`G
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/** The whole constructor */ 0@'-g^PS
public Page(boolean hasPrePage, boolean hasNextPage, M&Q&be84
)sIzBC
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int everyPage, int totalPage, 4%v-)HGh
int currentPage, int beginIndex){ D@w&[IF
this.hasPrePage = hasPrePage; y1Br4K5C
this.hasNextPage = hasNextPage; BThrv$D}
this.everyPage = everyPage; q=cnY+p>
this.totalPage = totalPage; l}S96B
this.currentPage = currentPage; Or/YEt}
this.beginIndex = beginIndex; SPTx-b[
} 1N]-WCxQ
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/** Xhyc2DKa_
* @return 2MXg)GBcU>
* Returns the beginIndex. ,uO?f1
*/ gvjy'Rm
publicint getBeginIndex(){ 4.%/u@rAi
return beginIndex; sN[<{;K4
} q 3,p=ijJ
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/** }i;!p
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* @param beginIndex ,mp^t2
* The beginIndex to set. Kv5 !cll5
*/ !M6Km(>
publicvoid setBeginIndex(int beginIndex){ a$11u.\q+
this.beginIndex = beginIndex; mk-L3H1@J3
} %E":Wv
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/** 5n2}|V$VqP
* @return 8
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* Returns the currentPage. QUdF`_U7
*/ ui*CA^ Y
publicint getCurrentPage(){ }WNgKw
return currentPage; y9GaxW*&