Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 mH5[(?
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 LRKl3"M
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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 6/l{e)rX2o
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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 N^xk.O_TO
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分页支持类: ^^{7`X
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java代码: CK#SD|~:
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package com.javaeye.common.util; M\)(_I)V=
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import java.util.List; (#5TM1/A
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publicclass PaginationSupport { I'a&n}jx
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publicfinalstaticint PAGESIZE = 30; jb0LMl}/A
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privateint pageSize = PAGESIZE; ~-K<gT/
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privateList items; #xe-Yw1!
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privateint totalCount; @&}~r
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privateint[] indexes = newint[0]; Fa^I 1fk
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privateint startIndex = 0; _0
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public PaginationSupport(List items, int Ph/!a6y
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totalCount){ 3{R7y
setPageSize(PAGESIZE); U7le> d;L
setTotalCount(totalCount); 7B8.;0X$W
setItems(items); }S}9Pm,:
setStartIndex(0); /Lt Lu
} >do3*koA
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public PaginationSupport(List items, int o}VW%G"
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totalCount, int startIndex){ qTi%].F"G
setPageSize(PAGESIZE); SVj4K\F
setTotalCount(totalCount); @o4n!Ip2x/
setItems(items); VKb'!Ystl
setStartIndex(startIndex); 8V(-S,
} $<v{$UOh
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public PaginationSupport(List items, int SED_^
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totalCount, int pageSize, int startIndex){ iIO_d4Z
setPageSize(pageSize); &HIG776
setTotalCount(totalCount); GK\`8xWE
setItems(items); gaa;PX
setStartIndex(startIndex); #(f- cK
} V/CZcMY_
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publicList getItems(){ 5"o)^8!>
return items; usz H1@g'
} siK:?A@4D
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publicvoid setItems(List items){ JtGBNz!"
this.items = items; z4iZE*ZS
} RY9h^q*
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publicint getPageSize(){ aK4ZH}XHE"
return pageSize; h Lv_ER?
} Gp5[H}8K
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publicvoid setPageSize(int pageSize){ [|E|(@J
this.pageSize = pageSize; ?K/N{GK%{
} ITf,
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publicint getTotalCount(){ %.`<ud
return totalCount; sUTh}.[5
} |T;NoWO+
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publicvoid setTotalCount(int totalCount){ ts=KAdcJ
if(totalCount > 0){ I@9[
this.totalCount = totalCount; "5@k\?x"
int count = totalCount / ._5"FUg
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pageSize; &R~)/y0]
if(totalCount % pageSize > 0) IolKe:'>@
count++; :HTV 8;yc
indexes = newint[count]; ^DWhIxBh
for(int i = 0; i < count; i++){ :jUu_s}
indexes = pageSize * _q/UDf1
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i; 3I%F,-r
} @ - _lw
}else{ A:5B6Z
this.totalCount = 0; #mvOhu
} cW*p}hD
} DgB]y6~KXl
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publicint[] getIndexes(){ \]gUX-
return indexes; sUEvL(%nY
} XEvDtDR
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publicvoid setIndexes(int[] indexes){ syR
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this.indexes = indexes; 4kqgZtg.
} ]f<H?
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publicint getStartIndex(){ Y]-7T-*+t
return startIndex; hfQx$cv6
} \yNe5
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publicvoid setStartIndex(int startIndex){ Z;4pI@u
if(totalCount <= 0) ->29Tns
this.startIndex = 0; sn6:\X<[
elseif(startIndex >= totalCount) A(dWAe,
this.startIndex = indexes lX*IEAc
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[indexes.length - 1];
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elseif(startIndex < 0) pk5W!K
this.startIndex = 0; M);@XcS
else{ U6M3,"?
this.startIndex = indexes k~+(X|!5w
}'.k
[startIndex / pageSize]; pcl'!8&7
} nm.~~h+8M
} h..D1(M
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publicint getNextIndex(){ ?.%'[n>P
int nextIndex = getStartIndex() + 4EtP|
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pageSize; Pk6l*+"r<
if(nextIndex >= totalCount) B[Gl}(E
return getStartIndex(); knU=#
else ;[}<xw3):
return nextIndex; .o?"=Epo
} \gE6KE<?p
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publicint getPreviousIndex(){ :6}y gL*i
int previousIndex = getStartIndex() - Pm*N!:u
q;{# ~<"+
pageSize; Kf!8PR$
if(previousIndex < 0) ~=xS\@UY =
return0; ?!$uMKyt
else >lg-j-pV
return previousIndex; O?I~XM'S
} ">V.nao
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} bw\a\/Dw
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抽象业务类 =5QP'Qt{O
java代码: 6JYVC>i
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/** 3TS(il9A
* Created on 2005-7-12 &&\HE7*
*/ O=Cz*j
package com.javaeye.common.business; |re>YQ!zd
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import java.io.Serializable; zYW+Goz/C
import java.util.List; r6#It$NU
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import org.hibernate.Criteria; Eoo[)V#x{
import org.hibernate.HibernateException; v|r=}`k=
import org.hibernate.Session; viP.G/(\]
import org.hibernate.criterion.DetachedCriteria; t"]+}]O
import org.hibernate.criterion.Projections; t|ih{0
import _ 3l ci
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org.springframework.orm.hibernate3.HibernateCallback; nn0`A3
import ygA~d9"
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org.springframework.orm.hibernate3.support.HibernateDaoS N7b+GqYpF>
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upport; +v7mw<6s
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import com.javaeye.common.util.PaginationSupport; #_b
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public abstract class AbstractManager extends j
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HibernateDaoSupport { \UF/_'=K
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privateboolean cacheQueries = false; Z"T#"FDIr
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privateString queryCacheRegion; `<z"BGQ
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publicvoid setCacheQueries(boolean ^D=1%@l?#
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cacheQueries){ el;ey Ga
this.cacheQueries = cacheQueries; 0"vI6Lm
} 2;z~xR
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publicvoid setQueryCacheRegion(String ~rN:4Q]/
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queryCacheRegion){ \.`;p
this.queryCacheRegion = Pr%Y!|
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queryCacheRegion; ^4\hZ
} 8-2e4^
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publicvoid save(finalObject entity){ w4m)lQM
getHibernateTemplate().save(entity); {7%W/C#A
} DLWG0$#!
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publicvoid persist(finalObject entity){ nI_43rG:Uf
getHibernateTemplate().save(entity); sr=~Uq{g
} gNsas:iGM
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publicvoid update(finalObject entity){ ( 2oP=9m
getHibernateTemplate().update(entity); Ju"*;/
} ;_HG
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publicvoid delete(finalObject entity){ R8*z}xy{
getHibernateTemplate().delete(entity); "
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} G=.vo3
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publicObject load(finalClass entity, 3($ cBC
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finalSerializable id){ .]0u#fz0y
return getHibernateTemplate().load 5 +Ei!E89
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(entity, id); oV(|51(f
} X4c|*U=4
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publicObject get(finalClass entity, _5nS!CN
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finalSerializable id){ ?nLlZpZ2v
return getHibernateTemplate().get LR:v$3 G(
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(entity, id); *CIR$sS
} V+A9.KoI
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publicList findAll(finalClass entity){ S[2uez`
return getHibernateTemplate().find("from g?e$B}%
&$1ifG
" + entity.getName()); &^v5 x"
} !R;NV|.eI6
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publicList findByNamedQuery(finalString ``zgw\f[%
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namedQuery){ ?YeUA =[MC
return getHibernateTemplate &!xePKvO6k
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().findByNamedQuery(namedQuery); W7F1o[
} $j+RUelFY
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publicList findByNamedQuery(finalString query, BrHw02G
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finalObject parameter){ )2t DX=D
return getHibernateTemplate #K:!s<_"
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().findByNamedQuery(query, parameter); AqdQiZ^9
} K-a~Kr
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publicList findByNamedQuery(finalString query, R">-h;#
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finalObject[] parameters){ va`/Dp)M
return getHibernateTemplate M/O
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().findByNamedQuery(query, parameters); %OIJ.
} 7CK3t/3D
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publicList find(finalString query){ isG8S(}IW&
return getHibernateTemplate().find Q1b<=,
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(query); 1I=>0c
} ^5MPK@)c,/
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publicList find(finalString query, finalObject yGxAur=dE
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parameter){ kK,Ne%}a2K
return getHibernateTemplate().find V!{}%;f
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(query, parameter); K+s@.D9J
} SU,#:s(
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public PaginationSupport findPageByCriteria c\J?J>xz
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(final DetachedCriteria detachedCriteria){ !Lu noC>B
return findPageByCriteria +E7Os|m
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ]T?Py)
} 8JFns-5
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public PaginationSupport findPageByCriteria ]52.nxs~
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(final DetachedCriteria detachedCriteria, finalint x$:P;#
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startIndex){ jDV;tEY#^
return findPageByCriteria m\0Xh*
tbH`VD"u
(detachedCriteria, PaginationSupport.PAGESIZE, zc`gm~@
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startIndex); #Ns]l<
} ]UMt
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public PaginationSupport findPageByCriteria |h7 d#V>
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(final DetachedCriteria detachedCriteria, finalint M3 TsalF
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pageSize, }%T8?d]
finalint startIndex){ C-}@.wr(
return(PaginationSupport) &P0jRT3e#Y
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getHibernateTemplate().execute(new HibernateCallback(){ w
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publicObject doInHibernate t)i{=8rq
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(Session session)throws HibernateException { (\I9eBm
Criteria criteria = pef)c,U$
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detachedCriteria.getExecutableCriteria(session); *3Vic
int totalCount = #B^A"?*S
"KiTjl`M,
((Integer) criteria.setProjection(Projections.rowCount )Z=S'm
k4_
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()).uniqueResult()).intValue(); 1^HmM"DD
criteria.setProjection u alpm#GU
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(null); 7~ I*u6zY
List items = L,+m5wKj[
}Z,x F`
criteria.setFirstResult(startIndex).setMaxResults 0p31C7!
e!B>M{
(pageSize).list(); >x3$Ld
PaginationSupport ps = Od,P,t9
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new PaginationSupport(items, totalCount, pageSize, - _KO}_
9'5`0$,|^
startIndex); 9*<=K
return ps; FB>^1B]]
} *M]@}'N
}, true); jR_o!n~5
} D^30R*gV
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public List findAllByCriteria(final yU{Q`6u T
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DetachedCriteria detachedCriteria){ v]?zG&Jh
return(List) getHibernateTemplate y!kU0
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().execute(new HibernateCallback(){ ]Uu :t
publicObject doInHibernate 6/=0RTd
b)(rlX
(Session session)throws HibernateException { d$gT,+|vu
Criteria criteria = #GbfFoE
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detachedCriteria.getExecutableCriteria(session); "8#EA<lsS
return criteria.list(); JnY.]:
} |nMg.t`8
}, true); yP^C)
} Pe,:FIp,
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public int getCountByCriteria(final `:Bm@eN
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DetachedCriteria detachedCriteria){ SmUj8?6"
Integer count = (Integer) !LX)
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getHibernateTemplate().execute(new HibernateCallback(){ r1A<XP|1?I
publicObject doInHibernate 49Q
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(Session session)throws HibernateException { Yf?hl
Criteria criteria = 51Q m2,P1^
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detachedCriteria.getExecutableCriteria(session); ?lPyapA]
return {u(( y D
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criteria.setProjection(Projections.rowCount Pea2ENe3
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()).uniqueResult(); 1va~.;/rG
} lvd`_+P$
}, true); m 5_
return count.intValue(); ^B!cL~S*I
} crbph.0
} X? l5}
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用户在web层构造查询条件detachedCriteria,和可选的 53<.Knw5a
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 /_[?i"GW
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PaginationSupport的实例ps。 35KRJY#
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ps.getItems()得到已分页好的结果集 )C>8B`^S
ps.getIndexes()得到分页索引的数组 #;])/8R%
ps.getTotalCount()得到总结果数 B(1WI_}~
ps.getStartIndex()当前分页索引 cfC}"As
ps.getNextIndex()下一页索引 V)Sw\tS6g
ps.getPreviousIndex()上一页索引 7SJbrOL4Q-
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 HJ+Q7)
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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 ' +f(9/
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一下代码重构了。 H{4_,2h=m
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我把原本我的做法也提供出来供大家讨论吧: =eyPo(B
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首先,为了实现分页查询,我封装了一个Page类: 5q;c=oRUj
java代码: z)ndj
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/*Created on 2005-4-14*/ ;Sl%I+?
package org.flyware.util.page; KsSIX
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/** x8o/m$[,=u
* @author Joa +n>p"+c
* QmC#1%@a
*/ c+upoM
publicclass Page { MG,)|XpyWJ
ZV;~IaBL
/** imply if the page has previous page */ qH4+iSTnV
privateboolean hasPrePage; t"nxny9&
7nPjeh
/** imply if the page has next page */ va2FgW`Bd+
privateboolean hasNextPage; ,*.qa0E#W
&,tj.?NCn
/** the number of every page */ DEW;0ic
privateint everyPage; 3Dx@rW\
-
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/** the total page number */ AfpC >>=@
privateint totalPage; NXMZTZpB7
O$7cN\Z
/** the number of current page */ >zfFvx_q
privateint currentPage; *Ksk1T+>
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/** the begin index of the records by the current pv,z$3Q
*RmD%[f
query */ K SJ Ko
privateint beginIndex; Z# %s/TL
+`7!4gxwK!
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/** The default constructor */ >mj WC) U
public Page(){ d*dPi^JjC
vDIsawbHD
} QIfP%,LT
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/** construct the page by everyPage /*(&Dmt>
* @param everyPage D67z6jep(
* */ Md&K#)9,(
public Page(int everyPage){ %6la@i
this.everyPage = everyPage; u
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} \olY)b[
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/** The whole constructor */ 0|kH0c,T-
public Page(boolean hasPrePage, boolean hasNextPage, 8p#V4liE
$ I
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int everyPage, int totalPage, KMx
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int currentPage, int beginIndex){ uNca@xl'
this.hasPrePage = hasPrePage; -^JPY)\R
this.hasNextPage = hasNextPage; A{Qo}F<*
this.everyPage = everyPage; a-lF}P\
this.totalPage = totalPage;
Wf~PP;
this.currentPage = currentPage; YIF|8b\
this.beginIndex = beginIndex; 3G'cDemc
} ^iWJqpLe
g"N&*V2
/** +LlAGg]Z
* @return I#'yy7J
* Returns the beginIndex. Dis kGq@T
*/ c`/kx
publicint getBeginIndex(){ !AGoI7W}
return beginIndex; Q$Rp?o&
} :o:Z
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/** :jJ0 +Q
* @param beginIndex iI3,q-LA
* The beginIndex to set. Z`#XB2,
*/ <B'PB"R3y
publicvoid setBeginIndex(int beginIndex){ +UiJWO
this.beginIndex = beginIndex; 8\G"I
} U,lO{J[T
+1r><do;
/** ts;^,|h
* @return B%5"B} nG
* Returns the currentPage. `~D{]'j
*/ 2Z ?l,M~
publicint getCurrentPage(){ $&Z<4:Flc
return currentPage; j8%Y[:~D
} y,K> Wb9e
gYloY=.Z$'
/** gX|\O']6
* @param currentPage >vXS6`;
* The currentPage to set. ^a$L9p(
*/ 8tO.o\)h
publicvoid setCurrentPage(int currentPage){ q{+}0!o
this.currentPage = currentPage; L\R(//V
} 4>/i,_&K K
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/** DPCQqV |7
* @return iba8G]2
* Returns the everyPage. z/nW;ow
*/ gGx<k3W^
publicint getEveryPage(){ ND/oKM+?
return everyPage; h
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} 6!8uZ>u%Vg
)@<HG$#
/** |{RCvm
* @param everyPage 9v1 Snr
* The everyPage to set. {;Oj
*/ 9m<%+S5&
publicvoid setEveryPage(int everyPage){ U;*O7K=P
this.everyPage = everyPage; ce*?crOV
} Kw2]J)TO
L* ScSxw
/** p.H`lbVY
* @return IJC]Al,df
* Returns the hasNextPage. etQS&YzC
*/ bP,Ka
publicboolean getHasNextPage(){ [[xnp;-;
return hasNextPage; g?K? Fn.}
} Gyrc~m[$
PR*EyM[T
/** 9<
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* @param hasNextPage F"QJ)F
* The hasNextPage to set. ;,7m
*/ u68ic1
publicvoid setHasNextPage(boolean hasNextPage){ c~}FYO$
this.hasNextPage = hasNextPage; BqM[{Kv
} =dmxE*C
@H^\PH?pp
/** x=X&b%09
* @return r?dkE=B
* Returns the hasPrePage. bR$5G
*/ J%
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publicboolean getHasPrePage(){ FC
return hasPrePage; N34bB>_
} d[*NDMO
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/** "ZA`Lp;%w
* @param hasPrePage _ q
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* The hasPrePage to set. Q.\vN-(
*/ "!uS!BI?
publicvoid setHasPrePage(boolean hasPrePage){ T5}5uk9
this.hasPrePage = hasPrePage; g|h;*
} Z_7TD)
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/** 1lJ^$U
* @return Returns the totalPage. 02)Ybp6y
* +UX}
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*/ vl?fCO
publicint getTotalPage(){ = )4bf"~8
return totalPage; 8#9OSupp
} "{3MXAFe
;Wsl 'e/
/** ]\]mwvLT
* @param totalPage ymT]ow6C
* The totalPage to set. prB:E[1
*/ 8#4Gs Q"
publicvoid setTotalPage(int totalPage){ um\A
this.totalPage = totalPage; L`fT;2
} }WF6w+
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} 9>ZX@1]m_
t}MT<Jj
CK_\K,xVT
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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 XhN?E-WywQ
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个PageUtil,负责对Page对象进行构造: r 5+ MjR
java代码: %o`Cp64`Q
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/*Created on 2005-4-14*/ =#wE*6T9
package org.flyware.util.page; T+FlN-iy)
dEo r+5}
import org.apache.commons.logging.Log; V#c=O}
import org.apache.commons.logging.LogFactory; 5bsv05=e
i98PlAq)B
/** Ct:c%D(L
* @author Joa y+izC+
* A2Iqn5
*/ g91xUG
publicclass PageUtil { ZS@R ?
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privatestaticfinal Log logger = LogFactory.getLog 8^R~qpg%
`_"?$ v2F
(PageUtil.class); C\|HN=2eh
zE7)4!
/** qQS&K%F
* Use the origin page to create a new page .
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* @param page 1KJ[&jS ]
* @param totalRecords M?kXzb\O
* @return 5RY rAzQo
*/ 1 -R4A7+3
publicstatic Page createPage(Page page, int
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"IWL& cH3
totalRecords){ w"A>mEex<
return createPage(page.getEveryPage(), "c![s%
$]?M[sL\N7
page.getCurrentPage(), totalRecords); W=2]!%3#
} ;)sC{ "Jb
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/** zCu+Oi6
* the basic page utils not including exception 6']WOM#
n.o_._mu2
handler 9$%S<v
* @param everyPage cO-^#di
* @param currentPage 0_t9;;y :
* @param totalRecords aDE}'d1qo
* @return page ^HHT>K-m
*/ SW Hi iF@
publicstatic Page createPage(int everyPage, int :;Npk9P(N
nrM-\'
currentPage, int totalRecords){ 'ztY>KV j
everyPage = getEveryPage(everyPage); yPH5/5;,
currentPage = getCurrentPage(currentPage); `|:` yl
int beginIndex = getBeginIndex(everyPage, uFOYyrESc
={{q_G\WD
currentPage); 4=|oOIhgb
int totalPage = getTotalPage(everyPage, yW i?2
$tK/3
totalRecords); |]?7r?=J9v
boolean hasNextPage = hasNextPage(currentPage, xDmwiVy
)=0@4
totalPage); VxU{ZD~<Z"
boolean hasPrePage = hasPrePage(currentPage); kQrby\F(<
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returnnew Page(hasPrePage, hasNextPage, i^rHZmT
everyPage, totalPage, 5[^Rf'wy
currentPage, BIT<J5>
x![ut
beginIndex);
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} jfZ)
_~!c%_
privatestaticint getEveryPage(int everyPage){ @rr\Jf""z
return everyPage == 0 ? 10 : everyPage; hr
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} BqOMg$<\[
al4X}
privatestaticint getCurrentPage(int currentPage){ kB-<17
return currentPage == 0 ? 1 : currentPage; m\K1Ex
} Jz-RMX=
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privatestaticint getBeginIndex(int everyPage, int ~e+pa|lO
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currentPage){ VJtRL')
return(currentPage - 1) * everyPage; <"LA70Hkk
} B>
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privatestaticint getTotalPage(int everyPage, int OL623jQX
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totalRecords){ XZ|\|(6Cc
int totalPage = 0; {.r9l
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if(totalRecords % everyPage == 0) H7Pw>Ta ;
totalPage = totalRecords / everyPage; Wk]E6yz6
else /? Bu^KX
totalPage = totalRecords / everyPage + 1 ; A&Cs
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return totalPage; i6E~]&~.v
}
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privatestaticboolean hasPrePage(int currentPage){ =%+xNOdN7?
return currentPage == 1 ? false : true; L#/<y{
} ,*;g+[Bhpl
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privatestaticboolean hasNextPage(int currentPage, 4TaHS!9
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int totalPage){ Kp/l2?J"
return currentPage == totalPage || totalPage == 'Y>@t6E4
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0 ? false : true; N\zUQ
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} sQT<I]e
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} wPpern05
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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。 !]#;'
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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 r5uX?^mJ0
. Kk'N
做法如下: DcZ,a E]
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 UFr5'T
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的信息,和一个结果集List: <*djtO
java代码: wUmcA~3D
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/*Created on 2005-6-13*/ m?`$NJST
package com.adt.bo; r7*'s
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import java.util.List; 6$p6dmV|
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import org.flyware.util.page.Page; v?S3G-r
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/** _MUSXB'
* @author Joa Qx77%L4
*/ vi0nJ -Xg
publicclass Result { N`5
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private Page page; x]|-2t
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private List content; t8"yAYj
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/** fb|lWEw5h.
* The default constructor _U%2J4T2
*/ nnMRp7LQ-
public Result(){ ((]Sy,rdk
super(); lhJZPnx~
} &y:SK)
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/** e}W|wJ):j@
* The constructor using fields MrpT5|t
* 76EMS?e
* @param page >3y:cPTM5
* @param content GP=&S|hi
*/ "A&