Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 7+hF1eoI
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 p> >H$t
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 ) c\Y!vS
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 @WS77d~S
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。 ^M6lF5
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分页支持类: 1J/'R37lP
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java代码: =hFY-~U
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package com.javaeye.common.util; MkoK(m{7
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import java.util.List; fxPg"R!1i
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publicclass PaginationSupport { :M6v<Kg{;
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publicfinalstaticint PAGESIZE = 30; `}#rcDK
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privateint pageSize = PAGESIZE; \8QOZjy
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privateList items; _8u TK%|
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privateint totalCount; *YeQCt-l
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privateint[] indexes = newint[0]; S\8v)|Pr
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privateint startIndex = 0; zU~ Ff"<
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public PaginationSupport(List items, int ?#=xx.cF
. waw=C
totalCount){ 'Tjvq%ks
setPageSize(PAGESIZE); "nu]3zcd
setTotalCount(totalCount); sb{K%xi%
setItems(items); KoNu{TJ
setStartIndex(0); >bf.T7wy
} /ki-Tha
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public PaginationSupport(List items, int ^%9oeT{
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totalCount, int startIndex){ "x=\mA#`
setPageSize(PAGESIZE); '?veMX
setTotalCount(totalCount); w/nohZF6H
setItems(items); %o%V4K*
setStartIndex(startIndex); ?<!qF:r:
} W^L^7
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public PaginationSupport(List items, int bKCE;Wu:G
;F"!$Z/
totalCount, int pageSize, int startIndex){ MIIl+
setPageSize(pageSize); ,7&\jET5^0
setTotalCount(totalCount); p!YK~cH[
setItems(items); Ldz]FB|
setStartIndex(startIndex); !2Nk
} xjo`u:BH
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publicList getItems(){ <3B^5p\/
return items; kPs?
} 80@\e
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publicvoid setItems(List items){ a(A~S u97
this.items = items; W|>jj$/o
} QLO;D)fC
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publicint getPageSize(){ FFcCoPX_
return pageSize; Z2$_9.
} R|\eBnfI
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publicvoid setPageSize(int pageSize){ -`k>(\Q<d
this.pageSize = pageSize; J.1c,@
} 0#J~@1Gf
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publicint getTotalCount(){ y 9]d{:9
return totalCount; NlEyT9
} Qjj }k)
.A< HM}
publicvoid setTotalCount(int totalCount){ ['}|#3*w
if(totalCount > 0){ _h-agn4[i
this.totalCount = totalCount; #Zm`*s`
int count = totalCount / {:gx*4}q8
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pageSize; crIF5^3Yby
if(totalCount % pageSize > 0) w"9h_;'C_
count++; h.vy SwF"j
indexes = newint[count]; f 3H uT=n
for(int i = 0; i < count; i++){ %1A8m-u]M
indexes = pageSize * 89&9VX^A
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i; #,#_"
} ;O hQBAC
}else{ |D)CAQn,
this.totalCount = 0; MF"*xr v
} Cb+sE"x]
} XS&Pc
*U1*/Q.
publicint[] getIndexes(){ (10t,n$
return indexes; nnPT08$
} b/UXO$_~-
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publicvoid setIndexes(int[] indexes){ m=6?%'
H}
this.indexes = indexes; v"1&xe^4
} E"E(<a
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publicint getStartIndex(){ |Gz<I
return startIndex; ([q>.[WbH]
} 7I[[S!((s
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publicvoid setStartIndex(int startIndex){ $=plAi
if(totalCount <= 0) `?$-T5Rr
this.startIndex = 0; 6n2RT H
elseif(startIndex >= totalCount) 2`]c&k;]
this.startIndex = indexes .vKgiIC:
c/K#W$ l
[indexes.length - 1]; hFA |(l6
elseif(startIndex < 0) DLbP$&o
this.startIndex = 0; !6|_`l>G,
else{ cY!Y?O
this.startIndex = indexes R WY>`.su
)2).kL>
[startIndex / pageSize]; ^IiA(?8
} \xS X'/G
} |gA@$1+}
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publicint getNextIndex(){ 'n7|fjX?Y
int nextIndex = getStartIndex() + YTTy6*\,_
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pageSize; qE2<vjRg
if(nextIndex >= totalCount)
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return getStartIndex(); c= 2E/x?
else
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return nextIndex; LeN }Q
} `{YOl\d_
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publicint getPreviousIndex(){ FiQ&g*=|
int previousIndex = getStartIndex() - uvl91~&G
g s1
pageSize; `GqF/?i
if(previousIndex < 0) 1N _"Mm{
return0; n2*Ua/J-8
else E7h@c>IK
return previousIndex; 7V=deYt_p
} tz65Tn_M
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} (1S9+H>g
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抽象业务类 W9gQho%9b
java代码: ;Uch
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@B{
/** fPN/Mxu
* Created on 2005-7-12 r|Uz?
*/ J-=fy^S5
package com.javaeye.common.business; 7oLl RU
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import java.io.Serializable; 8u[.s`^
import java.util.List; 1;./e&%%
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import org.hibernate.Criteria; vyc<RjS_x
import org.hibernate.HibernateException; d<?Zaehe\
import org.hibernate.Session; :OU(fz]
import org.hibernate.criterion.DetachedCriteria; aU +uPP
import org.hibernate.criterion.Projections; \zVp8MMf
import xg%{p``
vIi&D;
org.springframework.orm.hibernate3.HibernateCallback; i{:?Iw 'ay
import lKQjG+YF
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org.springframework.orm.hibernate3.support.HibernateDaoS #/(L.5d[
mMZ=9 ?m
upport; ]Gm&Kn>
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import com.javaeye.common.util.PaginationSupport; '#K~hep
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public abstract class AbstractManager extends K~&3etQF
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HibernateDaoSupport { C>l (4*S
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privateboolean cacheQueries = false; oPAc6ObOV~
`ER#S_}
privateString queryCacheRegion; >hnhV6ss
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publicvoid setCacheQueries(boolean ojWf]$^y}
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cacheQueries){ 1{xkAy0
this.cacheQueries = cacheQueries; |<YF.7r;
} g[{rX4~|
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publicvoid setQueryCacheRegion(String '~6l
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queryCacheRegion){ .}tpEvAw}
this.queryCacheRegion = w/0;N`YB
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queryCacheRegion; j~ qm5}
} FZ%
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publicvoid save(finalObject entity){ |R Qa.^.
getHibernateTemplate().save(entity); xiQd[[(sM
} 3t ]0
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publicvoid persist(finalObject entity){ TsRbIq[
getHibernateTemplate().save(entity); n22OPvp
} <,'^dR7,
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publicvoid update(finalObject entity){ .V^h< d{
getHibernateTemplate().update(entity); Eid~4a
} 6[1lK8o
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publicvoid delete(finalObject entity){ /%^^hr
getHibernateTemplate().delete(entity); ]O68~+6
}
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publicObject load(finalClass entity, V_Y2 @4
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finalSerializable id){ C'0=eel[
return getHibernateTemplate().load {[FJkP2l
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(entity, id); *&yt;|y
} P0szY"}
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publicObject get(finalClass entity, =Cr
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finalSerializable id){ K"ytE2:3
return getHibernateTemplate().get h]okY49hY
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(entity, id); /H[ !v:U
} ,n+~S^r
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publicList findAll(finalClass entity){ -qndBS
return getHibernateTemplate().find("from <D M:YWNa
Q|J$R
" + entity.getName()); l7=WO#Pb
} H;eOrX{GT
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publicList findByNamedQuery(finalString mq~L1<f
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namedQuery){ ZYX(Cf
return getHibernateTemplate .9;wJ9Bw[
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().findByNamedQuery(namedQuery); u~a@:D/F{G
} qy|si4IU8,
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publicList findByNamedQuery(finalString query, ;X3bgA']
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finalObject parameter){ DR6 OR B7
return getHibernateTemplate pI|H9
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().findByNamedQuery(query, parameter); *6e 5T
} Xz, sL
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publicList findByNamedQuery(finalString query, RI%ZT
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finalObject[] parameters){ h0fbc;l
return getHibernateTemplate c}>p"
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().findByNamedQuery(query, parameters); hVcV_
} ( nH3
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publicList find(finalString query){ yr
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return getHibernateTemplate().find Ag`:!*
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(query); {
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} `n!<h,S'2
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publicList find(finalString query, finalObject GUyc1{6
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parameter){ zV }-_u.
return getHibernateTemplate().find X>#!s Lt
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(query, parameter); rtz%(4aS
} J8"Cw<=O
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public PaginationSupport findPageByCriteria F:CqB|
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(final DetachedCriteria detachedCriteria){ .TURS
return findPageByCriteria `q
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q
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ,!f*OWnZ
} TWC^M{e
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public PaginationSupport findPageByCriteria 5s>$
@^vVou_
(final DetachedCriteria detachedCriteria, finalint XY5I5H_U
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startIndex){ <8Qa"<4f;
return findPageByCriteria ;&|ja]r
DiAPs_@
(detachedCriteria, PaginationSupport.PAGESIZE, 1X/
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startIndex); /0 ,#c2aq
} ?Ee HeN_
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public PaginationSupport findPageByCriteria 5w`v
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(final DetachedCriteria detachedCriteria, finalint 8KD7t&H
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pageSize, Z^AACKME
finalint startIndex){ Rtn.cSd
return(PaginationSupport) [t
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getHibernateTemplate().execute(new HibernateCallback(){ Xb42R1
publicObject doInHibernate -lyT8qZ:(
5-}4jwk
(Session session)throws HibernateException { RaAi9b[/S
Criteria criteria = `I<*R0Qe
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detachedCriteria.getExecutableCriteria(session); `7Ni bZX0
int totalCount = 3a_S-&?X
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((Integer) criteria.setProjection(Projections.rowCount AFl]w'=
)k3zOKZ;
()).uniqueResult()).intValue(); pSASMc@
criteria.setProjection 8|?$KLz?F>
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(null); \<~[uv'
List items = Q5iuK#/
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criteria.setFirstResult(startIndex).setMaxResults &M~*w~w`
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(pageSize).list(); F`U%xn,
PaginationSupport ps = uU6+cDp
7[:9vY
new PaginationSupport(items, totalCount, pageSize, DPi%[CRH
;]MHU/
startIndex); $r9Sn
return ps; H(!)]dO
} ,~gY'Ql
}, true); o8RagSIo8
} '>Y"s|
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public List findAllByCriteria(final ;&P%A<[`
eM+]KG)}
DetachedCriteria detachedCriteria){ N9Yc\?_NU_
return(List) getHibernateTemplate {Os$Uui37\
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().execute(new HibernateCallback(){ $TL~SVHj;{
publicObject doInHibernate _{KQQ5k\
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(Session session)throws HibernateException { "Q#/J)N
Criteria criteria = 93[c^sc9*a
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detachedCriteria.getExecutableCriteria(session); 8,#v7ns}#
return criteria.list(); KDuM;
} 2md1GWyP
}, true); 1Qtojph
}
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//\ORJd
public int getCountByCriteria(final iQZgs@
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DetachedCriteria detachedCriteria){ S>aN#
Integer count = (Integer) "CB*
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getHibernateTemplate().execute(new HibernateCallback(){ !!b5vzyve
publicObject doInHibernate $xyG0Q.
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(Session session)throws HibernateException { f:G Zb?Wyd
Criteria criteria = Ajr]&H4
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detachedCriteria.getExecutableCriteria(session); H ZIJKk(
return SgHLs
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criteria.setProjection(Projections.rowCount AiykIER/
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()).uniqueResult(); 07DpvhDQ
} p}hOkx4R\
}, true); ><viJ$i
return count.intValue(); D%N^iJC,9
} ~(aQ!!H6
} E5UI
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用户在web层构造查询条件detachedCriteria,和可选的 _$s9o$8$
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ]vMr@JM-G
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PaginationSupport的实例ps。 }+h/2D
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ps.getItems()得到已分页好的结果集 lOt3^`
ps.getIndexes()得到分页索引的数组 %g{m12
ps.getTotalCount()得到总结果数 o"->RC
ps.getStartIndex()当前分页索引 3xWeN#T0
ps.getNextIndex()下一页索引 %<CahzYc6
ps.getPreviousIndex()上一页索引 Wp`wIe6
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 I$9^i#O'3
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 ME7jF9d
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一下代码重构了。 rn #FmM
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cf
我把原本我的做法也提供出来供大家讨论吧: <RS@,
:^tw!U%y1
首先,为了实现分页查询,我封装了一个Page类: 6e3s
|
java代码: wN\%b}pp
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/*Created on 2005-4-14*/ `[p*qsp_
package org.flyware.util.page;
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[,Q(~Qb
/** ?Y7'OlO
* @author Joa XW
w=3$
* w?)v#]<-
*/ &4Q(>"iL4
publicclass Page { 3o&PVU?Q
s+&Ts|c#
/** imply if the page has previous page */ e>vV8a\
privateboolean hasPrePage; +e?mKLw14
3e4; '5q;
/** imply if the page has next page */ e6f:@ O?
privateboolean hasNextPage; /4J2F9:f
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/** the number of every page */ GO{o #}
privateint everyPage; "| 0g 1rd
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/** the total page number */ /` 891(f,
privateint totalPage; 20750G
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/** the number of current page */ F(c~D0
privateint currentPage; Dnn$-W|NC
gKy@$at&
/** the begin index of the records by the current VU3xP2c:
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query */ [,[;'::=o4
privateint beginIndex; _Mq0QQ42
vH/z|<
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/** The default constructor */ iU3)4(R
public Page(){ wv0d"PKTS
jiQJ{yY
} ,_;+H*H>"
8}9|hT;
/** construct the page by everyPage r2A%.bL#
* @param everyPage 3Z=OUhn9
* */ EV{kd.=f
public Page(int everyPage){ '{=dEEi
this.everyPage = everyPage; 4np,"^c
} ,0+%ji^V
w@RVg*`%7D
/** The whole constructor */ KNT(lA0s
public Page(boolean hasPrePage, boolean hasNextPage, #eSVFD5ZU
+p6cG\Gp
.BN~9w
int everyPage, int totalPage, [<SM*fQ>t
int currentPage, int beginIndex){ ^9*FYV
this.hasPrePage = hasPrePage; tYV%izE
this.hasNextPage = hasNextPage; LDlj4>%pW^
this.everyPage = everyPage; #?%akQ+w
this.totalPage = totalPage; '}\{4Qst
this.currentPage = currentPage; vzD3_
?D
this.beginIndex = beginIndex; l{oAqTN
} BDoL)}bRE
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/** `H+~LVH
* @return 8BZTHlUB
* Returns the beginIndex. Uw R,U#d
*/ Eq$Q%'5*ua
publicint getBeginIndex(){ |jB]5ciT
return beginIndex; U-.?+`
} p&1IK8i"
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/** 4T#B7wVoM
* @param beginIndex hKq <e%oVH
* The beginIndex to set. W\09hZ6
*/ j" wX7
publicvoid setBeginIndex(int beginIndex){ tln*Baq
this.beginIndex = beginIndex; {
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} Q*wub9
;)Rvk&J5
/** NJJsg^'
* @return .#n1p:}[
* Returns the currentPage. O8BxXa@5
*/ zt/p'khP3
publicint getCurrentPage(){ cU}j
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return currentPage; #PYTFB%
} A#9@OWV5f
f:5(M@iO.
/** 9/Q_Jv-Q
* @param currentPage bni :B?#
* The currentPage to set. hDc,#~!
*/ `q Sfo`
publicvoid setCurrentPage(int currentPage){ I}oxwc
this.currentPage = currentPage; mo%9UL,#W
} p"^^9'`=
uS :3Yo
/** > o{(f
* @return U85t !U
* Returns the everyPage. $-""=O|"
*/ X$,#OR
publicint getEveryPage(){ 4xLU15C
return everyPage; iN%\wkx*N
}
`o(PcX3/}
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/** Zyqh
* @param everyPage 2%g)0[1
* The everyPage to set. }vBk,ED
*/ .Ajs0 T2
publicvoid setEveryPage(int everyPage){ ^T\JFzV
this.everyPage = everyPage; Ikiv+Fq(
} ,2u-<8
{UT>>
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/** |YjuaXd7N
* @return RW
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* Returns the hasNextPage. jYKs| J)[
*/ LL Oe
publicboolean getHasNextPage(){ k!E`Xeob
return hasNextPage; MNip;S_j
} C/dqCUX:
2GECcx53
/** \2i4]V
* @param hasNextPage 7SYU^GD
* The hasNextPage to set. .(Q3M0.D
*/ 7]a6dMh
publicvoid setHasNextPage(boolean hasNextPage){ " ^~f.N
this.hasNextPage = hasNextPage; OI B~W
} Vea>T^
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/** p"ht|x
* @return 4A0R07"
* Returns the hasPrePage. sAS\-c'6
*/ R(@7$
publicboolean getHasPrePage(){ bnLvJ]i)
return hasPrePage; w'ZL'/d
} +g ovnx
I"*g-ji0
/** ~d_Z?Z
* @param hasPrePage s&Y~48{
* The hasPrePage to set. ;hNnF&l
*/ &!JX
publicvoid setHasPrePage(boolean hasPrePage){ {6'5K
U*RH
this.hasPrePage = hasPrePage; =3lUr<Ze
} ?,NZ/n
6d"dJV.\
/** KZeRbq2jJ
* @return Returns the totalPage. f33'2PYl
* 95^w" [}4Q
*/ \^SL Zhe
publicint getTotalPage(){ YTxUKE:
return totalPage; "?lirOD
} vjaIFyj
F6Z l#eL
/** T=:&W3
* @param totalPage =K{$?%"
* The totalPage to set. 5gZ0a4
*/ <=n$oMO
publicvoid setTotalPage(int totalPage){ sLzcTGa2:z
this.totalPage = totalPage; hJ#U;GL
} j(6:
r]Da4G^
} U#1T
HO`
^CI.F.#X|
u*{hXR-"
u].=b$wHHM
R+8+L|\wHv
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 )mxY]W+
o %A4wEye
个PageUtil,负责对Page对象进行构造: 6G7B&"&
java代码: `rW{zQYM
6tI7vLmG
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/*Created on 2005-4-14*/ l@4hBq
package org.flyware.util.page; )-|A|1Uo
Mkko1T=6
import org.apache.commons.logging.Log; \`jFy[(Pa'
import org.apache.commons.logging.LogFactory; e<YC=67n)
!V$nU8p|
/** m7z/@b[
* @author Joa >BMJA:j
* 6(B0gBCId
*/ 7xB#) o53
publicclass PageUtil { IJx dbuKg
c)#b*k,lw<
privatestaticfinal Log logger = LogFactory.getLog -]~U_J]
?`AzgM[I
(PageUtil.class); EK_NN<So#
*58<.L|
/** 9 }|Bs=q
* Use the origin page to create a new page FoWE<
* @param page R+P,kD?
* @param totalRecords 1Ls@|
* @return LTS3[=AB
*/ c~ l$_A
publicstatic Page createPage(Page page, int n7
4?W
3ypB~bNw
totalRecords){ Y<:%_]]
return createPage(page.getEveryPage(), i|Lir{vW
k<ku5U1|
page.getCurrentPage(), totalRecords); D(Zux8l
} ]2QZ47
RR{]^g51
/** }C"EkT!F
* the basic page utils not including exception SEr\ u#
=bded(3Z
handler 5aL0N
* @param everyPage ;T/W7=4CZ
* @param currentPage yC
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* @param totalRecords g}{Rk>k
* @return page S"CsY2;
*/ 6aK'%K
publicstatic Page createPage(int everyPage, int :(} {uG
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currentPage, int totalRecords){ 3lMmSKN
everyPage = getEveryPage(everyPage); tQ5gmj
currentPage = getCurrentPage(currentPage); S-gL]r3G8
int beginIndex = getBeginIndex(everyPage, ,aV89"}
Cj"k
Fq4
currentPage); %N|7<n<S
int totalPage = getTotalPage(everyPage, v#IW;Rj8
/(BQzCP9O;
totalRecords); *oY59Yf
boolean hasNextPage = hasNextPage(currentPage, (=CV")tF
wHWd~K_q
totalPage); L,[0*h
boolean hasPrePage = hasPrePage(currentPage); E$ q/4
<6mXlK3N0
returnnew Page(hasPrePage, hasNextPage, x/~V
ZO
everyPage, totalPage, kR%CSLOVy
currentPage, ]r$S{<
Nj %!N
beginIndex); w)&] k#r
} |D$U{5}Mv
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privatestaticint getEveryPage(int everyPage){ N1\u~%AT"
return everyPage == 0 ? 10 : everyPage; \x(J vDt
} d5T0#ue/e
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privatestaticint getCurrentPage(int currentPage){ @8DBLn w
return currentPage == 0 ? 1 : currentPage; 4M i*bN,
} # h/-
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privatestaticint getBeginIndex(int everyPage, int pHsp]a
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currentPage){ S!#7]wtbP
return(currentPage - 1) * everyPage; }{ pNasAU
} |5F]y"Nb
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privatestaticint getTotalPage(int everyPage, int Al$"k[-Uin
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totalRecords){ x|U]x
int totalPage = 0; _Eq:Qbw#
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if(totalRecords % everyPage == 0) 7eQ7\,^H
totalPage = totalRecords / everyPage; R{8nR00|1
else ,`P,))
totalPage = totalRecords / everyPage + 1 ; 00%$?Fyk
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return totalPage; Mn7 y@/1
} 6@wnF>'/\
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privatestaticboolean hasPrePage(int currentPage){ y:iE'SRRK6
return currentPage == 1 ? false : true; &%fy
} t<|=-
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privatestaticboolean hasNextPage(int currentPage, [k@D}p
x
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int totalPage){ {h&*H[Z z
return currentPage == totalPage || totalPage == _S,2j_R9
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0 ? false : true; 8$v17 3
} BtBy.bR
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} \
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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。 wjq f u /
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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 ~bigaY
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做法如下:
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1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 7#MBT-ih
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的信息,和一个结果集List: :&6QKTX
java代码: &5(|a"5+G
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/*Created on 2005-6-13*/ e1~C>
package com.adt.bo; wy&