Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 %8r/oS
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 !{Z~<Ky
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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 obo&1Uv,/
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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 Vrkf(E3_V
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分页支持类: :O-1rD
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java代码: wtH~-xSB|
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package com.javaeye.common.util; nxo+?:**
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import java.util.List; 1m@^E:w
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publicclass PaginationSupport { igC_)C^i>
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publicfinalstaticint PAGESIZE = 30; 'V&Y[7Aeq
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privateint pageSize = PAGESIZE; W?Ww2Lo%Y
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privateList items; v=?2S
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privateint totalCount; {38bv.3'
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privateint[] indexes = newint[0]; 3tAU?sV!
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privateint startIndex = 0; r ?m6$
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public PaginationSupport(List items, int ?cy4&]s
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totalCount){ }q[Bd
setPageSize(PAGESIZE); v]VWDT
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setTotalCount(totalCount); k cuzB+
setItems(items); vbG]mMJ
setStartIndex(0); k G0Yh2;#
} 5&!c7$K0
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public PaginationSupport(List items, int >3.X?
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totalCount, int startIndex){ t^tmz PWA
setPageSize(PAGESIZE);
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setTotalCount(totalCount); f 2YLk
setItems(items); S<wj*"|.s
setStartIndex(startIndex); j2 %^qL
} j+IrqPKC^
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public PaginationSupport(List items, int +9;2xya2
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totalCount, int pageSize, int startIndex){ ??&<k
setPageSize(pageSize); ti @kKz
setTotalCount(totalCount); 5Wx~ZQZ
setItems(items); BMyzjteS+
setStartIndex(startIndex); /RnTQ4
} /e@H^Cgo
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publicList getItems(){ RP4Ku9hk
return items; d^E [|w;
} 2{|$T2?e
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publicvoid setItems(List items){ cC{"<fYF
this.items = items; qoMfSz"(
} Di.3113t
w?Ju5 5
publicint getPageSize(){ 0E`1HP"b
return pageSize; #U
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} *iA4:EIP
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publicvoid setPageSize(int pageSize){ _QOZsEe
this.pageSize = pageSize; EbNd=Z'J
} !^c@shLN4
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publicint getTotalCount(){ i]{1^pKq
return totalCount; ;E^K.6
} X;F8_+Np
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publicvoid setTotalCount(int totalCount){ =@x`?oe v
if(totalCount > 0){ ,MPB/j^o5!
this.totalCount = totalCount; ~Heb1tl;
int count = totalCount / rh*sbZ68>E
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pageSize; "UFs~S|e
if(totalCount % pageSize > 0) HeGYu?&
count++; qy1F*kY
indexes = newint[count]; I?#85l{>
for(int i = 0; i < count; i++){ bBcp9C)iY
indexes = pageSize * Elj_,z
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} [(kB
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}else{ . 5y"38e
this.totalCount = 0; Bh`N[\r
} PQmq5N6
} ?4H#G)F
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publicint[] getIndexes(){ m0w;8uF2UV
return indexes; y;cUl, :v
} UB`ToE|Ii
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publicvoid setIndexes(int[] indexes){ WUc#)EEM)
this.indexes = indexes; \2-@' ^i
} Xr63?N
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publicint getStartIndex(){ T VmH
return startIndex; /'2O.d0}.
} o Pci66
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publicvoid setStartIndex(int startIndex){ g1E~+@
if(totalCount <= 0) Jq.lT(E8D
this.startIndex = 0; N{SQ(%V
elseif(startIndex >= totalCount) /PBaIoJE
this.startIndex = indexes @!N-RQ&A
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[indexes.length - 1]; \`V$
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elseif(startIndex < 0) 'nQVj
this.startIndex = 0; 5wao1sd#
else{ gF=jf2{YX
this.startIndex = indexes WF&[HKOy/
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[startIndex / pageSize]; sxKf&p;
} dCe4u<so\
} x&Vm!,%:1
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publicint getNextIndex(){ G0 J4O!3
int nextIndex = getStartIndex() + \6?A!w~6
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pageSize; Snly UP~P
if(nextIndex >= totalCount) qW:)!z3\
return getStartIndex(); =\#%j|9N9
else yH 9!GS#
return nextIndex; &;,,H< p
} z{"2S="
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publicint getPreviousIndex(){ HjqB^|z
int previousIndex = getStartIndex() - &c(WE
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pageSize; 9j]sD/L5q
if(previousIndex < 0) f %lD08Sl
return0; 87%*+n:?*
else H7Uli]e3
return previousIndex; )Au6Nf
} iqQUtE]E_
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} )D'^3)FF
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抽象业务类 `~eX55W
java代码: ;=j@,
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/** oRKEJNps
* Created on 2005-7-12 5(W"-A}
*/ ML-)I&>tT
package com.javaeye.common.business; G2LK]
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import java.io.Serializable; M<SdPC(+
import java.util.List; 50TA:7
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import org.hibernate.Criteria; L@75-T
import org.hibernate.HibernateException; QIN."&qC^
import org.hibernate.Session; SvN9aD1
import org.hibernate.criterion.DetachedCriteria; +_v$!@L8
import org.hibernate.criterion.Projections; ZvYLL{>}w
import /(.6bv
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org.springframework.orm.hibernate3.HibernateCallback; nzjkX4KV
import n9pN6,o+
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org.springframework.orm.hibernate3.support.HibernateDaoS {7cX#1
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upport; Uie?9&3
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import com.javaeye.common.util.PaginationSupport; 6{[pou&
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public abstract class AbstractManager extends 'Y$R~e^Y?
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HibernateDaoSupport { ;fw1
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privateboolean cacheQueries = false; ze_{=Cv&Y
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privateString queryCacheRegion; \;VhYvEH
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publicvoid setCacheQueries(boolean ]
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cacheQueries){ 2^t#6XBk/
this.cacheQueries = cacheQueries; d=,%=@
} < B_Vc:Q
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publicvoid setQueryCacheRegion(String Cv$
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queryCacheRegion){ w ;daC(:
this.queryCacheRegion = T081G`li
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queryCacheRegion; QDpEb=|S
} o7B[R) 4
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publicvoid save(finalObject entity){ zkTp`>9R
getHibernateTemplate().save(entity); U yw-2]!n
} V{|}}b?w?
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publicvoid persist(finalObject entity){ Rwr 2gMt7
getHibernateTemplate().save(entity); <Sz52Suh>
} 5XuT={o
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publicvoid update(finalObject entity){ 0-LpqX
getHibernateTemplate().update(entity); C^QtSha
} ,!V]jP)
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publicvoid delete(finalObject entity){ |uW:r17
getHibernateTemplate().delete(entity); [1 Ydo`
} 1!pa;$L
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publicObject load(finalClass entity, >3awn*N
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finalSerializable id){ j)t+jcMUI
return getHibernateTemplate().load {0! ~C=P
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(entity, id); CG'.:`t
} Ro2d,'
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publicObject get(finalClass entity, 1 T130L
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finalSerializable id){
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return getHibernateTemplate().get bCZ gcN
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(entity, id); ++L?+^h
} kE
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publicList findAll(finalClass entity){ " P)*FT
return getHibernateTemplate().find("from TO2c"7td
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" + entity.getName()); X-Wz:NA
} 6<0n *&
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publicList findByNamedQuery(finalString r_EcMIuk
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namedQuery){ :';L/x>
return getHibernateTemplate [FUjnI
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().findByNamedQuery(namedQuery); >;z<j$;F<
} 3:%QB9qc]'
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publicList findByNamedQuery(finalString query, 10#oG{9
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finalObject parameter){ a?yMHb{F
return getHibernateTemplate RtG}h[k/X
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().findByNamedQuery(query, parameter); &D%(~|'
} V|)>{Xdn
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publicList findByNamedQuery(finalString query, 'WHHc 9rG,
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finalObject[] parameters){ @pGZLq
return getHibernateTemplate iut`7
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().findByNamedQuery(query, parameters); 0?WcoPU
} v){ .Z^_C
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publicList find(finalString query){ W)(^m},*8D
return getHibernateTemplate().find E{HY!L[
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(query); J/7R\;q`~o
} M8k"je7`s
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publicList find(finalString query, finalObject ]CU]pK?nq
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parameter){ vaf&X]p
return getHibernateTemplate().find _WX#a|4h{
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(query, parameter); nS()u}c;r
} EL3|u64GO
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public PaginationSupport findPageByCriteria OdMO=Hy6d
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(final DetachedCriteria detachedCriteria){ reo{*)%
return findPageByCriteria co_oMc
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 5q@LxDy,b
} !h&g7do]Z
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public PaginationSupport findPageByCriteria Bh&Ew
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(final DetachedCriteria detachedCriteria, finalint :hGPTf
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startIndex){ MH|]\
return findPageByCriteria @{h?+
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(detachedCriteria, PaginationSupport.PAGESIZE, >]'yK!a?
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startIndex); pIWI
} [NnauItI
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public PaginationSupport findPageByCriteria =TR,~8Z|
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(final DetachedCriteria detachedCriteria, finalint 5>9Y|UU
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pageSize,
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finalint startIndex){ -#-p1^v}
return(PaginationSupport) OPpjuIRv
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getHibernateTemplate().execute(new HibernateCallback(){ %/kyT%1
publicObject doInHibernate Z?MoJ{.!?R
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(Session session)throws HibernateException { r%Rs0)$yj
Criteria criteria = _eLWQ|6Fx
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detachedCriteria.getExecutableCriteria(session); fpM#XFj
int totalCount = HEK-L)S.
*
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((Integer) criteria.setProjection(Projections.rowCount -6Tk<W
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()).uniqueResult()).intValue(); \^*<
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criteria.setProjection j:5%ppIY
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(null); '%v#v 3'
List items = N132sN2
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criteria.setFirstResult(startIndex).setMaxResults ~
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(pageSize).list(); I
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PaginationSupport ps = NGjdG=,
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new PaginationSupport(items, totalCount, pageSize, 4{9d#[KW
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startIndex); s(ROgCO
return ps; 8F;>5i
} ,KW;2t*IQ@
}, true); zH)_vW
} D)='8jV7
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public List findAllByCriteria(final pw>m.=9|y
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DetachedCriteria detachedCriteria){ B7NtkMK
return(List) getHibernateTemplate mkvvNm3
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().execute(new HibernateCallback(){ tP
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publicObject doInHibernate 9-h.|T2il
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(Session session)throws HibernateException { Mjpo1dw
Criteria criteria = ~QG?k
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detachedCriteria.getExecutableCriteria(session); \hk/1/siyF
return criteria.list(); QHf$f@bjI
} <v]9lw'
}, true); .I?@o8'x
} M\/XP| 7
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public int getCountByCriteria(final 5#:pT
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DetachedCriteria detachedCriteria){ SVP:D3)
Integer count = (Integer) ph30'"[Z}
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getHibernateTemplate().execute(new HibernateCallback(){ H;_yRUY9
publicObject doInHibernate wV<7pi
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(Session session)throws HibernateException { +Al>2 ~
Criteria criteria = Iur9I>8h
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detachedCriteria.getExecutableCriteria(session); dK?);*w]
return o sdOw8
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criteria.setProjection(Projections.rowCount I{.HO<$7D}
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()).uniqueResult(); H;vZm[\0N-
} Z-Wfcnk
}, true); OS7RQw1
return count.intValue(); 6o}V@UzqV
} go|>o5!g
} SPy3~Db-o
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用户在web层构造查询条件detachedCriteria,和可选的 5rN_jC*U
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 to3?$-L
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PaginationSupport的实例ps。 4\Di,PPu
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ps.getItems()得到已分页好的结果集 W}gVIfe
ps.getIndexes()得到分页索引的数组 X\2_;zwf
ps.getTotalCount()得到总结果数 {Bs+G/?o/
ps.getStartIndex()当前分页索引 XCPb9<L
ps.getNextIndex()下一页索引 r%MyR8'k]
ps.getPreviousIndex()上一页索引 F?*k}]Gi
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 wa?+qiWnrl
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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 JLUms
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一下代码重构了。 Cg6;I.K
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我把原本我的做法也提供出来供大家讨论吧: 70`M,``
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首先,为了实现分页查询,我封装了一个Page类: Y^eX@dEFR
java代码: ?[SVqj2-
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/*Created on 2005-4-14*/ kkfCAM
package org.flyware.util.page; }u^:MI
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/** Uz>Yn&{y6
* @author Joa ~= 9Vv
* ZQLB`n@
*/ Y@:3 B:m#
publicclass Page { XARSGAuw
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/** imply if the page has previous page */ vahf]2jEB
privateboolean hasPrePage; aJQXJ,>Lv
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/** imply if the page has next page */ \]a uSO
privateboolean hasNextPage; WB;J1TpM7
#_p
/** the number of every page */ jEE_D +K
privateint everyPage; ^Ezcy?
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/** the total page number */ *^6k[3VY
privateint totalPage; t'Htx1#Zc[
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/** the number of current page */ rG5i-'
privateint currentPage; =F[lg?g
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/** the begin index of the records by the current +9~ZA3DiP
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query */ z (#Xca
privateint beginIndex; 5:_~mlfi
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G4);/#
/** The default constructor */ C&oxi$J:p+
public Page(){ :+1bg&wQ
jDp]R_i
} hgif]?:C<
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/** construct the page by everyPage jqqaw
* @param everyPage ;$[VX/A`f
* */ `x< 0A
public Page(int everyPage){ [BE:+ ID3
this.everyPage = everyPage; F]Pul|.l
} q"l>`KCG`
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/** The whole constructor */ 'iGMn_&
public Page(boolean hasPrePage, boolean hasNextPage, jiOf')d5
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int everyPage, int totalPage, Ta,u-!/I
int currentPage, int beginIndex){ ew/KZE
this.hasPrePage = hasPrePage; Do(PdF6A
this.hasNextPage = hasNextPage; (OQi%/Oy
this.everyPage = everyPage; QZ:v
this.totalPage = totalPage; %!D_q~"H
this.currentPage = currentPage; I}1fEw>8
this.beginIndex = beginIndex; =^ gvZ|]
} AwA1&mh
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/** QM7[ O]@
* @return 3l.Nz@a*
* Returns the beginIndex. |zg=+
*/ y K=S!7p\
publicint getBeginIndex(){ N.k+AQb
return beginIndex; %oMWcgsdJi
} ho(5r5SNE
~ }Kp
/** <)=3XEcb
* @param beginIndex `s#sE.=o
* The beginIndex to set. \;'_|bu3.
*/ 1+VY><=n
publicvoid setBeginIndex(int beginIndex){ ,K`E&hS
this.beginIndex = beginIndex; #IbS
} Bd/}
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/** Q>##hG:m
* @return i#Ne'q;T
* Returns the currentPage. t@l(xns V
*/ PjiNu.>2(
publicint getCurrentPage(){ ;*n_N!v
return currentPage; S a(yjF1
} C+ZQB)gn
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/**
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* @param currentPage XPGL3[w\V
* The currentPage to set. cH+h=E=
*/ (R9QBZP5
publicvoid setCurrentPage(int currentPage){ "``W6W-(
this.currentPage = currentPage; /h1dm,
} bEoB;]
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/** 0\8*S3,q
* @return !hwzKm=%N
* Returns the everyPage. -[i40
1
*/ f)p>nW?Z
publicint getEveryPage(){ a3b2nAI l
return everyPage; >DPds~k
} '-$))AdD
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/** *%P>x}6w3
* @param everyPage YlZYS'_
* The everyPage to set. "#_)G7W+e
*/ Gp?ToS2^d
publicvoid setEveryPage(int everyPage){ 8@9hU`H8l
this.everyPage = everyPage; i}v}K'`
} sBeP;ox
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/** (= S"Kvb~#
* @return .(TQ5/
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* Returns the hasNextPage. CVyx lc>
*/ X|lElN
publicboolean getHasNextPage(){ SH@
return hasNextPage; yv6Zo0s<J
} Q#yu(
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/** ,(;p(#F>
* @param hasNextPage lp37irI:
* The hasNextPage to set. N (:E K
*/ 7 K;'7
publicvoid setHasNextPage(boolean hasNextPage){ 1B9Fb.i
this.hasNextPage = hasNextPage; !q7;{/QM6
} X]3l| D
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/** kuKnJWv
* @return _rWM]
* Returns the hasPrePage. +l[Z2mW
*/ <wd4^Vr!2
publicboolean getHasPrePage(){ Z>>gXh<e[
return hasPrePage; XudH
} $ g1wK}B3
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/** !%Z)eO~Z
* @param hasPrePage gLXvw]
* The hasPrePage to set. v;N1'
*/ iECC@g@a
publicvoid setHasPrePage(boolean hasPrePage){ {|7OmslC@
this.hasPrePage = hasPrePage; ,N))=/
} |2t7G9[n
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/** ?:{0
* @return Returns the totalPage. p ?Ij-uo"o
* QXIbFv
*/ (d5vH)+A
publicint getTotalPage(){ d
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return totalPage; LoV*YSDAY
} 3H\b N4
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/** 8zWBXV
* @param totalPage Y7b,td1
* The totalPage to set. N$ qNe'b
*/ K8yyxJ
publicvoid setTotalPage(int totalPage){ Y_Z
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this.totalPage = totalPage; ^Q43)H0
} L_.xr
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} )LMBxyS
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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 3
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个PageUtil,负责对Page对象进行构造: x jP" 'yU
java代码: @LkW_
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/*Created on 2005-4-14*/ 'wT./&Z
package org.flyware.util.page; "ojD f3@{
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import org.apache.commons.logging.Log; a dz;N;rIY
import org.apache.commons.logging.LogFactory; @$b+~X)7
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/** v @I^:I
* @author Joa S#0|#Z5qD
* 9bzYADLI
*/ u%gm+NneK
publicclass PageUtil { *`pec3"
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privatestaticfinal Log logger = LogFactory.getLog EDa08+Y
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(PageUtil.class); r/s&ee
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/** O7<V@GL+
* Use the origin page to create a new page /O(;~1B
* @param page x1hs19s
* @param totalRecords 8HH.P`Vk#
* @return 9>$%F;JP44
*/ <g|nmu)o$
publicstatic Page createPage(Page page, int aD2CDu
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totalRecords){ N:gstp
return createPage(page.getEveryPage(), 9T0wdK]
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page.getCurrentPage(), totalRecords); dn.c#,Y
} s$nfY.C
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/** L+0N@`nRF
* the basic page utils not including exception dv4r\ R^
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handler ][$$
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* @param everyPage aY1#K6(y
* @param currentPage ~E:/oV:4 >
* @param totalRecords )V+Dqh,-g
* @return page UXdC<(vK
*/ dE9aE# o
publicstatic Page createPage(int everyPage, int C>K"ZJ
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currentPage, int totalRecords){ 0 *Yivx6
everyPage = getEveryPage(everyPage); 0\ytBxL
currentPage = getCurrentPage(currentPage); )mo|.L0
int beginIndex = getBeginIndex(everyPage, ~pBxFA
7zkm
currentPage); EpoQV ^Ey
int totalPage = getTotalPage(everyPage, xzf)_ <
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totalRecords); Y @ ,e
boolean hasNextPage = hasNextPage(currentPage, CPCB!8-5
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totalPage); Rx"VscB6z
boolean hasPrePage = hasPrePage(currentPage); 9787uj]Y}H
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returnnew Page(hasPrePage, hasNextPage, <wGTs6
everyPage, totalPage, $MVeMgPa
currentPage, XuAc3~HAd
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beginIndex); wCE fR!i
} kU9AfAe
[.#$hOsNR
privatestaticint getEveryPage(int everyPage){ !\|@{UJk/
return everyPage == 0 ? 10 : everyPage; &)'kX
} w7ABnX
8w@jUGsc
privatestaticint getCurrentPage(int currentPage){ GMp'KEQQ
return currentPage == 0 ? 1 : currentPage; %$-3fj7
} [`nyq )
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privatestaticint getBeginIndex(int everyPage, int Z.Y8 z#[xg
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currentPage){ 'A@Oia1;{
return(currentPage - 1) * everyPage; i~PZvxt
} )da8Ru
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privatestaticint getTotalPage(int everyPage, int WRyv
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totalRecords){ KqIe8bi^G
int totalPage = 0; / z>8XM&
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if(totalRecords % everyPage == 0) 2OOj8JS
totalPage = totalRecords / everyPage; O#Ax P}
else :QY 9p T
totalPage = totalRecords / everyPage + 1 ; p.7p,CyB
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return totalPage; o+23?A~+
} ;."{0gq
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privatestaticboolean hasPrePage(int currentPage){ ]tV{#iIJ*
return currentPage == 1 ? false : true; leqSS}KU+
} )$.9WlQ
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privatestaticboolean hasNextPage(int currentPage, L7'X7WYf&
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int totalPage){ W$ {sD|d-
return currentPage == totalPage || totalPage == Xpz-@fqKdf
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0 ? false : true; 6*oTT(0<p
} 9jFDBy+
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} jtC ob'n8
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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。 ?4dd|n
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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 d`*vJ#$>2
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做法如下: \}(-9dr
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 8#3cmpx4
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的信息,和一个结果集List: T>?1+mruM
java代码: Xq$0% WjG
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/*Created on 2005-6-13*/ PU\q.y0R
package com.adt.bo; #.K&]OV/88
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import java.util.List; l1j
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import org.flyware.util.page.Page; $9b6,Y_-
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/** sMo%Ayes
* @author Joa l )eaIOyk
*/ dz DssAHy
publicclass Result { z>q_]U0
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private Page page; XX+rf
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private List content; <AXYqH7%A
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/** B9 {DO
* The default constructor iTyApLV
*/ $a]dxRkz
public Result(){ D{}\7qe
super(); 4iPg_+
} T{Q&