Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ;7P'>j1?U
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 3=.YQE0!dx
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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 Z A(u"T~
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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 s * (a
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分页支持类: M`cxxDj&j
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java代码: 5s[nE\oaG
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package com.javaeye.common.util; O-(V`BZe
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import java.util.List; "#~>q(4^
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publicclass PaginationSupport { "
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publicfinalstaticint PAGESIZE = 30; e(t}$Q=
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privateint pageSize = PAGESIZE; zS%XmS\
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privateList items; *BsK6iVb
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privateint totalCount; q^aDZzx,z
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privateint[] indexes = newint[0]; 0fOhCxtL@
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privateint startIndex = 0; gA2Wo+\^bq
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public PaginationSupport(List items, int {srP3ll
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totalCount){ f!'i5I]
setPageSize(PAGESIZE); fp [gKRSF
setTotalCount(totalCount); 4'O,xC
setItems(items); ?9~^QRLT
setStartIndex(0); (7R?T}
} y#GHmHeh
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public PaginationSupport(List items, int OH
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totalCount, int startIndex){ >bW=oTFz
setPageSize(PAGESIZE); T-] {gc
setTotalCount(totalCount); ?Lg(,-:
setItems(items); )]P(!hW.
setStartIndex(startIndex); :F:1(FDP
} h1_Z&VJ
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public PaginationSupport(List items, int \|,| )
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totalCount, int pageSize, int startIndex){ P{o)Ir8Tt
setPageSize(pageSize); ^QS`H@+Z
setTotalCount(totalCount); ]E/0iM5
setItems(items); zZ%[SW&vC
setStartIndex(startIndex); '7?Y+R@|L
} x%EGxs;>^
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publicList getItems(){ Fl`U{03
return items; %YR&>j
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} KsKE#])&l
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publicvoid setItems(List items){ \Bo$
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this.items = items; !6(3Y
} qZd*'ki<
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publicint getPageSize(){ '[#y|
return pageSize; u9"=t
} 7P<VtS
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publicvoid setPageSize(int pageSize){ l'"nU6B&
this.pageSize = pageSize;
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} P73GH
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publicint getTotalCount(){ 99=~vNn
return totalCount; NH/A`Wm
} Tx.N#,T|
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publicvoid setTotalCount(int totalCount){ u$d[&|`>_
if(totalCount > 0){ <\#'o}
this.totalCount = totalCount; UePkSz9EU
int count = totalCount / '-v:"%s|
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pageSize; [^"*I.Z_
if(totalCount % pageSize > 0) ^C'S-2nGH
count++; KqGb+N-@
indexes = newint[count]; ~[Tcl
for(int i = 0; i < count; i++){ GQbr}xX.#
indexes = pageSize * On*I.~
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} "-&K!Vfs
}else{ y RxrfAdS
this.totalCount = 0; jSp&\Wj b
} Qf~>5(,h
} M{jXo%C
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publicint[] getIndexes(){ dL0Q8d\^T
return indexes; 6&$.E! z
} $'V^_|EL7
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publicvoid setIndexes(int[] indexes){ <odi>!ViH
this.indexes = indexes; XM:BMd|
} "L~Oj&AN[
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publicint getStartIndex(){ cpOt?XYR~
return startIndex; hL3up] pZ
} __g?xw
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publicvoid setStartIndex(int startIndex){ )-4c@
if(totalCount <= 0) SMZ*30i
this.startIndex = 0; b=EI?XwJ
elseif(startIndex >= totalCount) !P{ /;Q
this.startIndex = indexes |Y!^E %*
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[indexes.length - 1]; +Csb8
elseif(startIndex < 0) ZN}`A7
this.startIndex = 0; l!,tssQ
else{ ZD&F ,2v
this.startIndex = indexes $V87=_}
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[startIndex / pageSize]; 6(QfD](2}
} p(RF
} B!+c74
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publicint getNextIndex(){ y[i}iT/~
int nextIndex = getStartIndex() + c[-N A
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pageSize; Nr*l3Z>LD
if(nextIndex >= totalCount)
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return getStartIndex(); QP'sS*saJ
else ?6_]^:s
return nextIndex; b:S$oE
} @|:fm()
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publicint getPreviousIndex(){ ('7?"npd
int previousIndex = getStartIndex() - )x!q;^Js9A
5, ;\zSz
pageSize; 8[@,i|kgg0
if(previousIndex < 0) +'m9b7+v
return0; zLl-{Kk
else }5fd:B m;
return previousIndex; f6I)c$]Q
} 5X^\AW
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} ~3s?.[}d
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抽象业务类 HB )+.e
java代码: "[
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/** _`SDG5
* Created on 2005-7-12 CNRSc4Le
*/ XgxO:"B
package com.javaeye.common.business; W<q<}RSn
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import java.io.Serializable; G+=Gc(J
import java.util.List; bg|$1ue
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import org.hibernate.Criteria; S5JMt;O
import org.hibernate.HibernateException; )Cdw_Yx
import org.hibernate.Session; L!JC)p.
import org.hibernate.criterion.DetachedCriteria; Pjh;;k|V
import org.hibernate.criterion.Projections; BZ\="N#f
import Ihf>FMl:
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org.springframework.orm.hibernate3.HibernateCallback; vL _yM
import "vk]y
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org.springframework.orm.hibernate3.support.HibernateDaoS B6F!"
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upport; x6K_!L*Fx]
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import com.javaeye.common.util.PaginationSupport; \L>XF'o
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public abstract class AbstractManager extends 6KGT?d
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HibernateDaoSupport { ubB1a_7
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privateboolean cacheQueries = false; MZ%J
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privateString queryCacheRegion; OX.5olb
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publicvoid setCacheQueries(boolean | K|AUI
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cacheQueries){ lfBCzxifC
this.cacheQueries = cacheQueries; `0ZH=*P
} PoZ$3V$(Lz
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publicvoid setQueryCacheRegion(String G!`%.tH
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queryCacheRegion){ eLT3b6'"?
this.queryCacheRegion = ~V(>L=\V;
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queryCacheRegion; UK
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} F$>#P7ph\a
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publicvoid save(finalObject entity){ t[k ['<G
getHibernateTemplate().save(entity); h<3bv&oI .
} Rm3W&hQ
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publicvoid persist(finalObject entity){ YQ+8lANC
getHibernateTemplate().save(entity); X%-"b`
} jA8Bmwt;w
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publicvoid update(finalObject entity){ 1<h@^s ;
getHibernateTemplate().update(entity); &5jc
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} I!F&8B+|
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publicvoid delete(finalObject entity){ R:P),
getHibernateTemplate().delete(entity); 4qDa:D"5
} g&RhPrtl
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publicObject load(finalClass entity, (M;d*gNr
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finalSerializable id){ atZNX1LD[/
return getHibernateTemplate().load 3q'nO-KJ
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(entity, id); [*K9V/
} y=8KNseW|
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publicObject get(finalClass entity, B$c'^
)
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finalSerializable id){ L?N:4/0;!
return getHibernateTemplate().get *#p}FB2H#
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(entity, id); 7.{+8#~nV
} F6{
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publicList findAll(finalClass entity){ /W>?p@j+K
return getHibernateTemplate().find("from aIT0t0.
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" + entity.getName()); r
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} 6I~M8Lo;
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publicList findByNamedQuery(finalString `-s]dq
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namedQuery){ .4 NcaMj
return getHibernateTemplate 1OY
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().findByNamedQuery(namedQuery); &B8x0 yi
} 0I)eYksh
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publicList findByNamedQuery(finalString query, iMM9a;G+
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finalObject parameter){ Q&$2F:4f&
return getHibernateTemplate xE_~.EoB
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().findByNamedQuery(query, parameter); BDL[C<d(
} |I]G=.*E
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publicList findByNamedQuery(finalString query, &6GW9pl[
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finalObject[] parameters){ (<`>B
return getHibernateTemplate M;g"rpM
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().findByNamedQuery(query, parameters); }uD*\.
} ZDK+>^A)
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publicList find(finalString query){ q.hpnE~#lh
return getHibernateTemplate().find sz7<u|
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(query); 6C_H0a/h&
} j%S}
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publicList find(finalString query, finalObject ZV/g_i#
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parameter){ Ta8lc %0w3
return getHibernateTemplate().find %Q93n {?
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(query, parameter); yBqKldl
} >U:.5Tch'V
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public PaginationSupport findPageByCriteria R,hwn2@B
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(final DetachedCriteria detachedCriteria){ i1qmFvksl
return findPageByCriteria b5
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); =VSUE
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} CrGDo9JdvT
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public PaginationSupport findPageByCriteria w`Cs,
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(final DetachedCriteria detachedCriteria, finalint n7#}i2:
Cj)*JZVG
startIndex){ -C*UB
return findPageByCriteria .A6Jj4`-
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(detachedCriteria, PaginationSupport.PAGESIZE, uw&p)
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startIndex); Coe%R(x5
} G{'`L)~3N
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public PaginationSupport findPageByCriteria R5cpmCs@R
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(final DetachedCriteria detachedCriteria, finalint l5Q-M{w0x
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pageSize, %vWh1-
finalint startIndex){ #"JtH"pF
return(PaginationSupport) !y;xt?
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getHibernateTemplate().execute(new HibernateCallback(){ l !R >I7
publicObject doInHibernate 78zwu<ET
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(Session session)throws HibernateException { PAjH*5IA
Criteria criteria = 0e~4(2xK
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detachedCriteria.getExecutableCriteria(session); RZ9chTX/
int totalCount = Z&Z=24q_
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((Integer) criteria.setProjection(Projections.rowCount !X{>?.@~
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()).uniqueResult()).intValue(); )cRP6 =
criteria.setProjection 1NU@k6UHl
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(null); li)shp)
List items = :}~B;s0M\
}FAO.
criteria.setFirstResult(startIndex).setMaxResults D]5cijO6
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(pageSize).list(); II}3w#r4
PaginationSupport ps = ujoJ6UOG
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new PaginationSupport(items, totalCount, pageSize, IaYy5Rw
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startIndex); ;fKFmY41
return ps; /: }"Z b
} ~`CWpc:
}, true); 4wx_@8
} k9oLJ<.k
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public List findAllByCriteria(final af;~<oa
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DetachedCriteria detachedCriteria){ QR{pph*zn-
return(List) getHibernateTemplate p V`)
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().execute(new HibernateCallback(){ 2mPU /
publicObject doInHibernate [f@[gE
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(Session session)throws HibernateException { -x0u}I
Criteria criteria = S5xum_Dq
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detachedCriteria.getExecutableCriteria(session);
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return criteria.list(); @xPWR=Lb
} ~V!gHJ5M
}, true); <(dg^;
} L[.RV*sL
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public int getCountByCriteria(final l]__!X
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DetachedCriteria detachedCriteria){ bZzB\FB~
Integer count = (Integer) _(J/$D
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getHibernateTemplate().execute(new HibernateCallback(){ 9/I|oh_
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publicObject doInHibernate w4\g]\
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(Session session)throws HibernateException { .Fn7yTQ%
Criteria criteria = ;UDd4@3`S"
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detachedCriteria.getExecutableCriteria(session); s&~i S[
return -}Q^A_xK
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criteria.setProjection(Projections.rowCount <gbm
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`_5{:
9N$
()).uniqueResult(); 9w( Wtw'
} gOKF%Ej31T
}, true); T9O3$1eqfo
return count.intValue(); L<MH:
} A&/YnJ"
} u:s[6T0
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用户在web层构造查询条件detachedCriteria,和可选的 z ,q1TU9
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 S{F'k;x/5
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PaginationSupport的实例ps。 SK G!DKQ
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ps.getItems()得到已分页好的结果集 qD<\U
ps.getIndexes()得到分页索引的数组 wj#A#[e
ps.getTotalCount()得到总结果数 S[5e,Ew
ps.getStartIndex()当前分页索引 ^
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ps.getNextIndex()下一页索引 wwD?i.3
ps.getPreviousIndex()上一页索引 X4Y!Z/b
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ?kKr/f4N
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 Z_}[hz$
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一下代码重构了。 #Qnl,lf
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我把原本我的做法也提供出来供大家讨论吧: )=@SA`J
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首先,为了实现分页查询,我封装了一个Page类: 65||]l
java代码: rf]'VJg#3
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/*Created on 2005-4-14*/ qxW^\u!<
package org.flyware.util.page; "0]s|ys6<
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/** HH3Ln+AWg_
* @author Joa 7ajkp+E6
* .`Rju|l
*/ nYbI =_-
publicclass Page { <Gkmk?x`A
z)&ZoSXWc
/** imply if the page has previous page */ ^7>k:|7-t
privateboolean hasPrePage; IMtfi(Y%F
"D1u2>(
/** imply if the page has next page */ i]M:ntB"
privateboolean hasNextPage; *
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2GC{+*
/** the number of every page */ 9qXKHro
privateint everyPage; }Z Nyd
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/** the total page number */ E[2>je
privateint totalPage; 5w$\x+no
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/** the number of current page */ dAkJ5\=*
privateint currentPage; 052ezh_
0JS#{EDh+
/** the begin index of the records by the current O{w'i|
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query */ ?vr9l7VOi
privateint beginIndex; hX&Jq%{oa
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/** The default constructor */ YR/%0^M'0
public Page(){ 6h%_\I.Z[[
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} ?f'iS#XL
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/** construct the page by everyPage vS'l@`Eg]
* @param everyPage t`oH7)nut
* */ q@0g KC&U
public Page(int everyPage){ *j"u~ NF
this.everyPage = everyPage; FQW{c3%qZ
} |fhYft
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f*
/** The whole constructor */ d:SLyFD$q
public Page(boolean hasPrePage, boolean hasNextPage, h}SP`
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int everyPage, int totalPage, bHf>EU
int currentPage, int beginIndex){ Tw+V$:$$
this.hasPrePage = hasPrePage; nXFPoR)T
this.hasNextPage = hasNextPage; (`me}8
this.everyPage = everyPage; xq-TT2}<L
this.totalPage = totalPage; pf[m"t6G~
this.currentPage = currentPage; %Z]c[V.
this.beginIndex = beginIndex; b"7L
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} PRQEk.C
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/** yHNx,ra
* @return )g
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* Returns the beginIndex. o`+$h:zm@
*/ @r=v*hu
publicint getBeginIndex(){ ;VW->ia6
return beginIndex; ;V)jC
} FBGe s[,
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/** 2vh@KnNU
* @param beginIndex K2
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* The beginIndex to set. B57MzIZi]
*/ #WqpU.
publicvoid setBeginIndex(int beginIndex){ c]1\88
this.beginIndex = beginIndex; YQ$EN>.eO
}
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/** <TQ,7M4X
* @return b<E+5;u
* Returns the currentPage. ^<OcbOn;O
*/ .4O~a
publicint getCurrentPage(){ "HwSW4a]
return currentPage; 5 ^867
} -XNawpl`
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/** s9aa _Th
* @param currentPage u/ZV35z
* The currentPage to set. 4];<`
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*/ iRK&-wn
publicvoid setCurrentPage(int currentPage){ KJ#SE|
this.currentPage = currentPage; oGvk,mh"(
} e~P4>3
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/** hSgH;k
* @return
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* Returns the everyPage. VqL#w<A%
*/ "J"RH:$v
publicint getEveryPage(){ H9%[!
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return everyPage; GJ Takhj3
} P1qQ)-J
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/** !))!!{
* @param everyPage HnsPXF'8g
* The everyPage to set. K=N8O8R$y
*/ t/B4?A@C
publicvoid setEveryPage(int everyPage){ Vf#g~IOI
this.everyPage = everyPage; o*sss
} [!ilcHE)
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/** ,,=VF(@G
* @return F!7\Za,
* Returns the hasNextPage. ?A]/
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*/ $w+()iI
publicboolean getHasNextPage(){ ?XllPnuKt%
return hasNextPage; M.3ULt8
} JA2oy09G
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/** ^@HWw@GA
* @param hasNextPage 31&;3?3>
* The hasNextPage to set.
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*/ )K!!Zq3;|
publicvoid setHasNextPage(boolean hasNextPage){ iiLDl
this.hasNextPage = hasNextPage; {M
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} Bg.
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/** \5P 5N]]
* @return x T1MW
* Returns the hasPrePage. X4CiVV
*/ j.kv!;Rj=
publicboolean getHasPrePage(){ nq
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return hasPrePage; k7kPeq
} L};P*{q2Z
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/** a[=;6!
* @param hasPrePage 5$ &',v(
* The hasPrePage to set. utU;M*
*/ 5Zuk`%O
publicvoid setHasPrePage(boolean hasPrePage){ ^;'FC vd
this.hasPrePage = hasPrePage; Xmw%f[Xl
} Jp"[` m
Vy 7 )_D
/** 45Lzq6
* @return Returns the totalPage. oq9gFJG(
* FBeo@
*/ N nq r{ub
publicint getTotalPage(){ _%KRZx}
return totalPage; rEwd76?
} p]rV\,Yss
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/** I<qG{PA
* @param totalPage 6
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* The totalPage to set. ${{[g16X
*/ WI1DL&*B@<
publicvoid setTotalPage(int totalPage){ snP]&l+
this.totalPage = totalPage; 2(km]H^
} I#/"6%e
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} <9]J/w+
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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 +zf`_1+)U
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个PageUtil,负责对Page对象进行构造: C:.>*;?7
java代码: 4mvnFY}
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7U:{=+oLR
/*Created on 2005-4-14*/ v >cPr(
package org.flyware.util.page; L),r\#Y(v
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import org.apache.commons.logging.Log; }b^x#HC
import org.apache.commons.logging.LogFactory; vG:S(/\>
V ;"Rp-`^
/** !b?cY{
* @author Joa K!(hj '0.
* U#`2~Qv/1
*/ ^qLesP#
publicclass PageUtil { " ~q~)T1Z
iL|5}x5\
privatestaticfinal Log logger = LogFactory.getLog ujf7r`;u.
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(PageUtil.class); N!./u(b
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/** p\Fxt1Y@X
* Use the origin page to create a new page 3Xm>
3
* @param page a5 pXn v]A
* @param totalRecords gOr%N!5
* @return M7{_"9X{
*/ 8On MtP
publicstatic Page createPage(Page page, int ?8FJMFv;4%
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totalRecords){ '4}8WYKQ
return createPage(page.getEveryPage(), : . PRM+
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page.getCurrentPage(), totalRecords);
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} ~-UO^$M-
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/** &t6:1 T
* the basic page utils not including exception h-\Ov{~
vlFq-W!
handler N]-skz<v
* @param everyPage >z73uKA(
* @param currentPage R&Ss ET.
* @param totalRecords <{i1/"k?X
* @return page Js^(mRv=
*/ Zr(eH2}0D
publicstatic Page createPage(int everyPage, int eQ*zi9na
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currentPage, int totalRecords){ 3R%yKa#
everyPage = getEveryPage(everyPage); i:Gyi([C
currentPage = getCurrentPage(currentPage); ~=9S AJr]
int beginIndex = getBeginIndex(everyPage, Qe_C^(P
rONz*ly|i
currentPage); WLiF D.
int totalPage = getTotalPage(everyPage, ^fE8|/]nG9
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totalRecords); `VF_rC[?
boolean hasNextPage = hasNextPage(currentPage, yb,$UT"]
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totalPage); <o/l K\>
boolean hasPrePage = hasPrePage(currentPage);
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returnnew Page(hasPrePage, hasNextPage, \jb62Jp
everyPage, totalPage, aq\Fh7
currentPage, ibLx'<
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beginIndex); DVf}='en8
} 5n1`$T.WG
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privatestaticint getEveryPage(int everyPage){ VQ8Fs/Zt!
return everyPage == 0 ? 10 : everyPage; xVRxKM5 {
} *P|~vCnr
P9 y+rF.
privatestaticint getCurrentPage(int currentPage){ 9@}5FoX"
return currentPage == 0 ? 1 : currentPage; P=7X+}@
} ^^< C9
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privatestaticint getBeginIndex(int everyPage, int Y#+Ws0wN
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currentPage){ +VL:O]`DJ
return(currentPage - 1) * everyPage; )l.AsfW%
} O8Z+g{
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privatestaticint getTotalPage(int everyPage, int .hUlI3z9
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totalRecords){ ""Oir!4
int totalPage = 0; PXML1.r$Q
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if(totalRecords % everyPage == 0) @|s$:;(=
totalPage = totalRecords / everyPage; HU$]o N
else F'CJN$6Mw/
totalPage = totalRecords / everyPage + 1 ; uG/'9C6Z
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return totalPage; brG!TJ
} KT+{-"4-
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privatestaticboolean hasPrePage(int currentPage){ d c/^
return currentPage == 1 ? false : true; RJKi98xwJ
} rITA-W O
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privatestaticboolean hasNextPage(int currentPage, `jyyRwSoe
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int totalPage){ w`fbUh6/
return currentPage == totalPage || totalPage == g<7Aln}Nl\
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0 ? false : true; :4\%a4{Ie
} ";7/8(LBZ
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} 6uKP
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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。 O#p_rfQ
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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 Ep:hObWG)
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做法如下: %yd(=%)fMB
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 y4$$*oai&
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的信息,和一个结果集List: B/o8r4[80
java代码: C+"c^9[
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/*Created on 2005-6-13*/ o7WAH@g
package com.adt.bo; ijvDFyN>
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import java.util.List; >P:U9
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import org.flyware.util.page.Page; fE_%,DJE(
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/** #9Fk&Lx
* @author Joa m )rVzL
*/ !m%'aQHH(
publicclass Result { ef_H*e
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private Page page; E'98JZ5ga
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private List content; :U=3*f.{
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/** Q1ayd$W@<
* The default constructor <mj/P|P@
*/ U OGjil{.
public Result(){ v*FbvrY
super(); vLBuE
} OU}eTc(FeC
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/** _0FMwC#DY
* The constructor using fields 6\jbSe
* D$>&K&
* @param page *wY+yoj
* @param content #:P$a%V
*/ ngmC~l*,
public Result(Page page, List content){ d:>'c=y
this.page = page; uK`gveY
this.content = content; >d &0a:
} D_[NzCv<-
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/** "\T-r 2
* @return Returns the content. RgJbM\`}?
*/ q5JQx**g
publicList getContent(){ fA]sPh4Uag
return content; Q672iR\#)
} Bha("kG
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/** I8% -ii
* @return Returns the page. e$WAf`*
*/ 6({)O1Z
public Page getPage(){ []aw;\7}Y
return page; pZlt4
} ]z8/S!?
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/** 8y
* @param content rx 74v!
* The content to set. 'DNxc
*/ IVZUB*wv)b
public void setContent(List content){ @$ Nti>
this.content = content; jkta]#O
} 6<>1,wbq
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/** Mis B&Ok`k
* @param page i$$h6P#
* The page to set. }9W[7V?
*/ 9N{?J"ido
publicvoid setPage(Page page){ = Ul"{T<
this.page = page; 7I#C[:7x
} ?e4H{Y/M
} @: =vK?8L
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2. 编写业务逻辑接口,并实现它(UserManager, qyFeq])
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UserManagerImpl) ]0 = |?n$7
java代码: GnUD<P=I
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/*Created on 2005-7-15*/ "crp/Bj?
package com.adt.service; OFmHj]I7=
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import net.sf.hibernate.HibernateException; 9`
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@t1pB]O:
import org.flyware.util.page.Page; q5hE S
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import com.adt.bo.Result; ?Js4\X!uJ
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/** B8"c+<b
* @author Joa V*fv>f:Yv
*/ .w@B )f*
publicinterface UserManager { +Ek1~i.
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public Result listUser(Page page)throws |<,0*2
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HibernateException; ,Eh]Zv1AE
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} "*j8G8
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