Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 p+{*&Hm5
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 f\vg<lca
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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 E#M4{a1
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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 /q6
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分页支持类: jb!15Vlt"
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java代码: !XrnD#
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package com.javaeye.common.util;
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import java.util.List; /Es&~Fn
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publicclass PaginationSupport { c *]6>50
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publicfinalstaticint PAGESIZE = 30; uSn<]OrZo`
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privateint pageSize = PAGESIZE; $_&gT.>
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privateList items; -JB~yO?0
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privateint totalCount; 5oR/Q|^
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privateint[] indexes = newint[0]; D= LLm$y
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privateint startIndex = 0; *u`[2xmuYf
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public PaginationSupport(List items, int >z1q\cz
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totalCount){ x$
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setPageSize(PAGESIZE); dw
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setTotalCount(totalCount); r1QLSD]i6
setItems(items); eZ[O:W vk:
setStartIndex(0); A +J&(7N
} d%='W|i\p&
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public PaginationSupport(List items, int 982n G-"
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totalCount, int startIndex){ q_|YLs`
setPageSize(PAGESIZE); {E+o+2L
setTotalCount(totalCount); E[N3`"
setItems(items); ct#3*]
setStartIndex(startIndex); v*k}{M
} ES&"zjr$
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public PaginationSupport(List items, int %uWq)D4r
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totalCount, int pageSize, int startIndex){ pN
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setPageSize(pageSize); =u#xPI0:
setTotalCount(totalCount); G`1FD
setItems(items); ^dF?MQA<@
setStartIndex(startIndex); ggn:DE"
} 6!GO{2d"
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publicList getItems(){ xJ18M@"j
return items; ui\yY3?
} Y={_o!9
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publicvoid setItems(List items){ g~i%*u,Y<
this.items = items; -U"h3Ye^
} `x0GT\O2-
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publicint getPageSize(){ utDjN"
return pageSize; );zLy?n
} *$eMM*4
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publicvoid setPageSize(int pageSize){ gLyE,1Z}u
this.pageSize = pageSize; lSu\VCG
} A*r6
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publicint getTotalCount(){ I#m0n%-[
return totalCount; \q0wY7w
} Xj^Hy"HC^~
Y%B:IeF}
publicvoid setTotalCount(int totalCount){ XsVp7zk\
if(totalCount > 0){ G2A^+R0\
this.totalCount = totalCount; LR5X=&k
int count = totalCount / )S;pYVVAl
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pageSize; <oc"!c;T
if(totalCount % pageSize > 0) ,'E+f%
count++; {|;5P.,l
indexes = newint[count]; Kn!n}GtR
for(int i = 0; i < count; i++){ GjmPpKIu\
indexes = pageSize * *C(/2
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i; /R2K3E#
} }5 2]
}else{ xTy[X"sJ
this.totalCount = 0; wstH&^
} H1alf_(_
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} +EtL+Y(U
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publicint[] getIndexes(){ \
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return indexes; Od?M4Ed(
} I(cy<ey+e
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publicvoid setIndexes(int[] indexes){ Y'75DE<BC
this.indexes = indexes; X/5\L.g2
} rM
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publicint getStartIndex(){ $[p<}o/6v]
return startIndex; yK$.wd2,
}
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publicvoid setStartIndex(int startIndex){ L=7U#Q/DE
if(totalCount <= 0) m_
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this.startIndex = 0; cZ!%#Az
elseif(startIndex >= totalCount) dW32O2@-
this.startIndex = indexes E!~Ok
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[indexes.length - 1]; Qj?qWVapA
elseif(startIndex < 0) U_ -9rkUa
this.startIndex = 0; "|2|Vju%
else{ "kE$2Kg
this.startIndex = indexes j2UiZLuV
1@ e22\
[startIndex / pageSize]; vS! TnmF
} i.|zKjF'
} bJ[{[|yEd
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publicint getNextIndex(){ f{b$Y3
int nextIndex = getStartIndex() + 'Xl_,;W]
/EN3>25"#
pageSize; D!K){E
if(nextIndex >= totalCount) zL1*w@6
return getStartIndex(); ileqI/40f
else sXD.*D
return nextIndex; Mw0Kg9M
} {^r8uKo:~
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publicint getPreviousIndex(){ xKilTh_.6
int previousIndex = getStartIndex() - y>:-6)pv
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pageSize; %R18
if(previousIndex < 0) F,t
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return0; ,a:!"Z^f
else j k%MP6
return previousIndex; *5SOXrvhu6
} H5L~[\
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} [k"@n+%
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抽象业务类 6`KAl rH
java代码: TRQ@=.
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/** E%R^
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* Created on 2005-7-12 8\z5* IPGs
*/ \DP*?D_}?
package com.javaeye.common.business; @yBg)1AL
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import java.io.Serializable; /H_,1Fu|
import java.util.List; 8hx4s(1!
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import org.hibernate.Criteria; M;BDo(1
import org.hibernate.HibernateException; 0KW@j>=jK
import org.hibernate.Session; ?\GILB,
import org.hibernate.criterion.DetachedCriteria; _JlbVe[<
import org.hibernate.criterion.Projections; '@Zau\xC
import `rt
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org.springframework.orm.hibernate3.HibernateCallback; 5r=xhOe`
import k7rFbrLZ
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org.springframework.orm.hibernate3.support.HibernateDaoS v/n4Lp$W^
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upport; P\;L#2n
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import com.javaeye.common.util.PaginationSupport; gy|L!_1Z8
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public abstract class AbstractManager extends 1Sk=;Bic
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HibernateDaoSupport { pwg$% lv
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privateboolean cacheQueries = false; !.(Kpcrg
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privateString queryCacheRegion; =oZHN,
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publicvoid setCacheQueries(boolean #6< X
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cacheQueries){ i/ED_<_Vg
this.cacheQueries = cacheQueries; >s
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} l)V!0eW
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publicvoid setQueryCacheRegion(String 8(yZX4OH>
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queryCacheRegion){ ]V|rOt xb
this.queryCacheRegion = ~vqVASUc,
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queryCacheRegion; UKYQ @m
} \!!qzrq
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publicvoid save(finalObject entity){ l;*/F`>c
getHibernateTemplate().save(entity); -6 WjYJx
} HGuU6@~hu
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publicvoid persist(finalObject entity){ Ttr)e:
getHibernateTemplate().save(entity); AYhWeI+
} ;kSRv=S
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publicvoid update(finalObject entity){ =NHE_4/p
getHibernateTemplate().update(entity); f`ro{p
} UL9]LEGG
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publicvoid delete(finalObject entity){ $w,?%i97
getHibernateTemplate().delete(entity); n$2IaE;v
} 0c2O'&$au
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publicObject load(finalClass entity, 9v\x&h
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finalSerializable id){ 1M1|Wp
return getHibernateTemplate().load $|kq{@<
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(entity, id); NCW<~
} qPI\Y3ZU
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publicObject get(finalClass entity, cTC -cgp
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finalSerializable id){ Lud[.>i
return getHibernateTemplate().get ?*oBevUnCY
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(entity, id); Tu!2lHK;
} QN4{xf:}S
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publicList findAll(finalClass entity){ _GhP{C$
return getHibernateTemplate().find("from 7 XNZEi9o
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" + entity.getName()); X!aC6gujOH
} O]-)?y/
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publicList findByNamedQuery(finalString {[|je]3v
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namedQuery){ ?|i
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return getHibernateTemplate ;JuBybJb
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().findByNamedQuery(namedQuery); 539fB,
} w"Q/ 6#!K
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publicList findByNamedQuery(finalString query, D'8xP %P
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finalObject parameter){ AjYvYMA&
return getHibernateTemplate .](~dVp%~
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().findByNamedQuery(query, parameter); [ML|,kq!
} gAudL)X
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publicList findByNamedQuery(finalString query, [PIh^DhK
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finalObject[] parameters){ *Cj<Vy
return getHibernateTemplate rq#\x{l
*^3&Y@
().findByNamedQuery(query, parameters); <"hq}B
} 0Yk$f1g
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publicList find(finalString query){ uFUVcWt
return getHibernateTemplate().find 8C=8Wjm
?mp}_x#=
(query); :!QT ,
} ;%Zu[G`C
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publicList find(finalString query, finalObject LOEiV
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parameter){ 3P *[!KI
return getHibernateTemplate().find D & Bdl5g
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(query, parameter); e9;5.m
} X/f?=U
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public PaginationSupport findPageByCriteria ce<88dL
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(final DetachedCriteria detachedCriteria){ GUps\:ss
return findPageByCriteria W|L#Q/
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); zi_0*znw
} q\G7T{t$.
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public PaginationSupport findPageByCriteria S=a>rnF
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(final DetachedCriteria detachedCriteria, finalint c=f;3N
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startIndex){ Xd@ d$
return findPageByCriteria QKI g5I-
ckkm}|&m
(detachedCriteria, PaginationSupport.PAGESIZE, 5
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startIndex); &9EcgazV
} N (0%C?
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public PaginationSupport findPageByCriteria Z_4|L+i<{
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(final DetachedCriteria detachedCriteria, finalint r8Z.}<j
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pageSize, r<[G~n
finalint startIndex){ "..I$R
return(PaginationSupport) I`nC\%g
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getHibernateTemplate().execute(new HibernateCallback(){ q4SEvP}fLx
publicObject doInHibernate |qf ef&
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(Session session)throws HibernateException { hm0MO,i"
Criteria criteria = Y+DVwz$
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detachedCriteria.getExecutableCriteria(session); H`4KhdqR
int totalCount = 4t 0p!IxG
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((Integer) criteria.setProjection(Projections.rowCount 'yR\%#s6
?>NX}~2cf
()).uniqueResult()).intValue(); SNC)cq+{
criteria.setProjection L0qL\>#ejr
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(null); qG3MyK%O\
List items = IM_SZs
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criteria.setFirstResult(startIndex).setMaxResults 13A~."b
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(pageSize).list(); )O8w'4P5
PaginationSupport ps = >]x%+@{|
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new PaginationSupport(items, totalCount, pageSize, z8j7K'vV1
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startIndex); ri49r*_1
return ps; sC_doh_M
} jxZ_-1
}, true); ,WE2MAjhT
} zd=N.
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public List findAllByCriteria(final 7*r!-$
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DetachedCriteria detachedCriteria){ or(P?Ro
return(List) getHibernateTemplate t\O#5mo
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().execute(new HibernateCallback(){ 2tS,q_-=
publicObject doInHibernate 8peK[sz
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(Session session)throws HibernateException { j2oU1' b
Criteria criteria = !.7m4mKzo
#'I<q
detachedCriteria.getExecutableCriteria(session); gRwRhA/
return criteria.list(); rnC<(f22
} {5(M
}, true); p+CK+m
} #<vzQ\~Y
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public int getCountByCriteria(final o4,9jk$
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DetachedCriteria detachedCriteria){ 6%&DJBU!
Integer count = (Integer) HBZtg
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getHibernateTemplate().execute(new HibernateCallback(){ $Zj3#l:rK
publicObject doInHibernate N~DO_^
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(Session session)throws HibernateException { fz rH}^
Criteria criteria = 54Vb[;`Kkb
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detachedCriteria.getExecutableCriteria(session); )Mh5q&ow
return Er|j\(jM
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criteria.setProjection(Projections.rowCount w +HKvOs5c
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()).uniqueResult(); _r`(P#Hy
} x) R4_3
}, true); Fyc":{Jd
return count.intValue(); 3u'@anre
} RA}Y$ }^#'
} q5.5%W
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用户在web层构造查询条件detachedCriteria,和可选的 "MDy0Tj8EN
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 fjHd"!)3
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PaginationSupport的实例ps。 WB" 90!
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ps.getItems()得到已分页好的结果集 Obc wmL
ps.getIndexes()得到分页索引的数组 -IL' (vx
ps.getTotalCount()得到总结果数 /?S,u,R
ps.getStartIndex()当前分页索引 }LX.gm
ps.getNextIndex()下一页索引
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ps.getPreviousIndex()上一页索引 YGZa##i
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 T>m|C}yy
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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 D`PA@t
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一下代码重构了。 BsYJIKfW
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我把原本我的做法也提供出来供大家讨论吧: mnM$#%q;%
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首先,为了实现分页查询,我封装了一个Page类: KvlLcE~`o
java代码: .;37 e
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/*Created on 2005-4-14*/ cN|
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package org.flyware.util.page; Sp@{5
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/** ?YnB:z*eV
* @author Joa <#e!kWGR?
* }?Tz=hP
*/ 4M>E QF&
publicclass Page { ^ ]SU (kY
yu=(m~KX
/** imply if the page has previous page */ BtKbX)R$J
privateboolean hasPrePage; %F] :nk`
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/** imply if the page has next page */ zG~nRt{4
privateboolean hasNextPage; nPjN\Es6
,/..f!bp
/** the number of every page */ vFsl]|<;8
privateint everyPage; Cx
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/** the total page number */ TuzH'F
privateint totalPage; $%5!CD1)
>('Z9<|r:
/** the number of current page */ 'h;x>r
privateint currentPage; O+o_{t\R
8#15*'Y
/** the begin index of the records by the current >FReGiK$T
GD
}i=TK
query */ -\}Ix>
privateint beginIndex; xMo'SpVz:
jLreN#:9
@'FO M
/** The default constructor */ i
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public Page(){ yx/.4DW1Ua
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} |1Pi`^
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/** construct the page by everyPage 4GqE%n+ta~
* @param everyPage f}+8m .g2
* */ ^|=3sJ4[U
public Page(int everyPage){ Mt+ggF.
this.everyPage = everyPage; Q#*Pjl
} M7SVD[7~HM
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/** The whole constructor */ 2f.4P]s`T
public Page(boolean hasPrePage, boolean hasNextPage, 3(>NS ?lX
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int everyPage, int totalPage, w1
tg7^(@
int currentPage, int beginIndex){ =bB7$#al
this.hasPrePage = hasPrePage; N!^5<2z@eT
this.hasNextPage = hasNextPage; ?$AWY\
this.everyPage = everyPage; /S&8%fb
this.totalPage = totalPage; f)!7/+9>
this.currentPage = currentPage; Y!lc/[8
this.beginIndex = beginIndex; J1{ucFa
} Af7&;8pM
+
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/** wv_<be[?*
* @return dLy-J1h\
* Returns the beginIndex. 5mB'\xGO2
*/ /V)4B4
publicint getBeginIndex(){ Gu@Znh-D
return beginIndex; hZNAI
} gVI2{\a
mY,t]#^m7
/** 9!|+GIjn
* @param beginIndex Ld3!2g2y7&
* The beginIndex to set. UIi`bbJ
*/ D'3. T{*rH
publicvoid setBeginIndex(int beginIndex){ +2S#3m?1
this.beginIndex = beginIndex; YUsMq3^&
} :T# "bY
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/** MJ0UZxnl
* @return *;yn_zg
* Returns the currentPage. f!aE/e\
*/ zCdzxb_h"
publicint getCurrentPage(){ ![a~y`<K,
return currentPage; 26<Wg7/,
} zaoC
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/** 1I -LGe[Q
* @param currentPage "[BDa}Il
* The currentPage to set. 0/P-> n~
*/ QGv:h[b_
publicvoid setCurrentPage(int currentPage){ renmz,dJ,
this.currentPage = currentPage; e4YfTr
} $
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/** z?uQlm*We
* @return $F@L$&~
* Returns the everyPage. w4fJ`,
*/ "o# )vA`
publicint getEveryPage(){ />^`*e_
return everyPage; E}b>7L&w
} .`Old{<
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/** .)^3t~
* @param everyPage v>y8s&/
* The everyPage to set. Y6<0%
*/ kk_9G-M
publicvoid setEveryPage(int everyPage){ 1|~#028
this.everyPage = everyPage; ksOANLRN
} IJ_'w[k
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/** \/'#=q1
* @return ;sck+FP7w
* Returns the hasNextPage. x)#<.DX
*/ *@G(3 n
publicboolean getHasNextPage(){ 4-d99|mv
return hasNextPage; CdzkMVH
} U8WHE=Kk\h
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/** B=q)}aWc
* @param hasNextPage 8!&ds~?
* The hasNextPage to set. ,p*ntj{
*/ ^Z-.[Y
publicvoid setHasNextPage(boolean hasNextPage){ /UaNYv/
this.hasNextPage = hasNextPage; :rTKqX&"j
} 9&XV}I,~?|
#.MIW*==
/** XMeL^|D
* @return i^yH?bH @~
* Returns the hasPrePage. -VreBKn
*/ 8tT&BmT
publicboolean getHasPrePage(){ G%j/eTTf
return hasPrePage; u"#6_-0y
} hyk|+z`B
W>q*.9}Y"
/** z,}c?BP
* @param hasPrePage Pghva*&
* The hasPrePage to set. cYq']$]
*/ oRT
publicvoid setHasPrePage(boolean hasPrePage){ H IPcZ!p
this.hasPrePage = hasPrePage; as\<nPT{Fj
} {.aK{
V
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/** NRHr6!f>
* @return Returns the totalPage. L)kb (TH
* Q*09E
*/ S{^6iR
publicint getTotalPage(){ >+Sv9S
return totalPage; PS_3Oq)
} ibZt2@GB)I
_S9rF-9G]
/** pW*{Mx
* @param totalPage "t(1tWO1o
* The totalPage to set. aW`:)y&f
*/ )XmCy"xx
publicvoid setTotalPage(int totalPage){ njy~
this.totalPage = totalPage; _dYf
} Lf,CxZL5
O3^98n2
} G*P[z'K=
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qy7hkq.uX
9]]!8_0=r
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 x !#Ma
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个PageUtil,负责对Page对象进行构造: .DgoOo%?"
java代码: 8Zcol$XS'
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/*Created on 2005-4-14*/ c8^+^.=pX
package org.flyware.util.page; d u.HSXK
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import org.apache.commons.logging.Log; l?3vNa FeR
import org.apache.commons.logging.LogFactory; %/{IssCR7
g8%MOhg
/** <MPeh&_3#
* @author Joa aqcFY8b
'
* tP}Xhn`
*/ @MNl*~'$.[
publicclass PageUtil { KotPV
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privatestaticfinal Log logger = LogFactory.getLog r/UYC"K3
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(PageUtil.class); n?y'c^
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/** lr9=OlH
* Use the origin page to create a new page >pgQb9
T+_
* @param page 8# 6\+R
* @param totalRecords Kg4QT/0VA
* @return Q{H17]W
*/ LiiK3!^i
publicstatic Page createPage(Page page, int eeZIa`.sX
i?ZA x4D
totalRecords){ 6{5q@9F
return createPage(page.getEveryPage(), IM@"AD52a
zx
ct(
page.getCurrentPage(), totalRecords); '
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} }16&1@8
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!
/** VMaS;)0f@
* the basic page utils not including exception +c-6#7hh
\|v `l{
handler Bk&-1>cY
* @param everyPage ]PeLcB
* @param currentPage /rqqC(1
* @param totalRecords 66/Z\H^d
* @return page [6O04"6K
*/ h8em\<;
publicstatic Page createPage(int everyPage, int zT$0xj8
cZ^wQ5=
currentPage, int totalRecords){ Kl2}o|b
everyPage = getEveryPage(everyPage); ~D*b3K8X
currentPage = getCurrentPage(currentPage); pfR"s:#
int beginIndex = getBeginIndex(everyPage, o1e4.-xI
h5x*NM1Ih
currentPage); n;%y
int totalPage = getTotalPage(everyPage, {z=j_;<]
xsYE=^uv
totalRecords); \$j^_C>
boolean hasNextPage = hasNextPage(currentPage, ZOp^`c9~
Jth=.9mrM
totalPage); r)Or\HL
boolean hasPrePage = hasPrePage(currentPage); =PV/`I_h
Rl1$?l6Rf
returnnew Page(hasPrePage, hasNextPage, n|6?J_{<b>
everyPage, totalPage, [$^A@bqk
currentPage, `N$!s7M
6nc0=~='$
beginIndex); n"iNKR>nW
} UkZ\cc}aC/
h!v/s=8c
privatestaticint getEveryPage(int everyPage){ bQ<b[
return everyPage == 0 ? 10 : everyPage; \<X2ns@Tf
} GYd]5`ri
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privatestaticint getCurrentPage(int currentPage){ w(Gz({l+
return currentPage == 0 ? 1 : currentPage; 7RD$=?o O'
} 3^XVQS***
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privatestaticint getBeginIndex(int everyPage, int <~N%W#z/
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currentPage){ U,'EF[t
return(currentPage - 1) * everyPage; 4#_$@ r
} :&9TW]*g
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privatestaticint getTotalPage(int everyPage, int x~EKGoz3
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totalRecords){ Ssf+b!e]
int totalPage = 0; +RS$5NLH
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if(totalRecords % everyPage == 0) 9_UN.]
totalPage = totalRecords / everyPage; IM=+3W;ak
else wd wp9 r
totalPage = totalRecords / everyPage + 1 ; 5}XvL'
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return totalPage; Ig9d#c
} +xZQJeKb
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privatestaticboolean hasPrePage(int currentPage){ x,\!DLq:p
return currentPage == 1 ? false : true; hg8Be6G<
} 3$_*N(e
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privatestaticboolean hasNextPage(int currentPage, t8/%Dgu
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int totalPage){ SO3cY#i
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return currentPage == totalPage || totalPage == "r. .
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0 ? false : true; \I:.<2i
} \ha-"Aqze3
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} @5E,:)T*wR
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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。 XYAmJ
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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 Qqq
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做法如下: g5Td("&n
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 8r^ ~0nm
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的信息,和一个结果集List: !h: Q
java代码: {Uq:Xw
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/*Created on 2005-6-13*/ H~o <AmE0!
package com.adt.bo; 2f,2rW^i
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import java.util.List; Lgi[u"Du
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import org.flyware.util.page.Page; .:9s}%Zr
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/** X3B{8qx_>
* @author Joa fdv`7u+}a
*/ Y7SacRO
publicclass Result { ][7p+IsB
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private Page page; 79BaDB`{a
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private List content; ~uj;qq
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/** >oJkJ$|wU
* The default constructor Uyx&E?SlEq
*/ y%cO#P@
public Result(){ YnTB&GPxl
super(); 9[Qd)%MO
} )/|6'L-2
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/** L*JPe"N-e
* The constructor using fields mT.e>/pa
* G>z,#Xt
* @param page z"
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* @param content Qa`hR
*/ )=^w3y
public Result(Page page, List content){ =?
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this.page = page; la^
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this.content = content; 23ze/;6%A
} pq!%?m]
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/** )S@jDaU<