Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 =cRJtn
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 TR:D
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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 4H1s"mP<
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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 6Ajiz_~U
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分页支持类: o'D6lkf0
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java代码: TH6g:YP`7
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package com.javaeye.common.util; a(BC(^1!
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import java.util.List; wetkmd
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publicclass PaginationSupport { pK$^@~DE
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publicfinalstaticint PAGESIZE = 30; 0BVMLRB
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privateint pageSize = PAGESIZE; !_V*VD
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privateList items; ZC0F:=/K
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privateint totalCount; d~[>%&
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privateint[] indexes = newint[0]; Ye(0'*-jyc
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privateint startIndex = 0; D;:lw]
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public PaginationSupport(List items, int \6@}HFH
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totalCount){ X\YeO>C
setPageSize(PAGESIZE); ]`UJwq
setTotalCount(totalCount); Iem* 'r
setItems(items); N 4,w
setStartIndex(0); u2U@Qrs2
} o*dhks[
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public PaginationSupport(List items, int rU'&o) a^
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totalCount, int startIndex){ cJH7zumM)
setPageSize(PAGESIZE); (cA=~Bw[=
setTotalCount(totalCount); ;l?>+m@H
setItems(items); v8wN2[fC
setStartIndex(startIndex); I#9K/[
} =#>P!
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public PaginationSupport(List items, int l kl#AH
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totalCount, int pageSize, int startIndex){ 1lx\Pz@ol
setPageSize(pageSize); _
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setTotalCount(totalCount); l sUQ7%f
setItems(items); 1 bv L
setStartIndex(startIndex); 9`vse>,-hg
} Cf%)W:Q9
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publicList getItems(){ =zbrXtp,
return items; X|.X4fs
} U(i2j)|^I3
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publicvoid setItems(List items){ $v>- @
this.items = items; T`vj6F
} Xv'64Nc!;
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publicint getPageSize(){ r4_ c~\jH
return pageSize; ~%GUc
~
} 5a_K|(~3I
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publicvoid setPageSize(int pageSize){ A}oR,$D-
this.pageSize = pageSize; cvc.-7IO
} B|!YGfL
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publicint getTotalCount(){ 9N-mIGJ
return totalCount; [.6uw=;o
} jPbL3"0A&
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publicvoid setTotalCount(int totalCount){ ;Hm\?n)a
if(totalCount > 0){ 0ED(e1K#B
this.totalCount = totalCount; f#5mX&j
int count = totalCount / sg9ZYWcL
s[Njk@y,
pageSize; ^
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if(totalCount % pageSize > 0) 8
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count++; 6i&WF<%D
indexes = newint[count]; w+ _'BU1#
for(int i = 0; i < count; i++){ rKR<R(=!=
indexes = pageSize * 2M|jWy _
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i; >\VZ9bP<
} +n%WmRf6!
}else{ qt3\*U7x
this.totalCount = 0; 3
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} uT;9xV%ch
} \N;s@j W
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publicint[] getIndexes(){ eaCEZHr$
return indexes; hp[8.Z$7
} "*TnkFTR
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publicvoid setIndexes(int[] indexes){ Y}F+4
this.indexes = indexes; ==|//:: \
} JqFFI:Q5a
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publicint getStartIndex(){ ,wnF]K2D0
return startIndex; Ak|jJ
} jQ`cfE$sV
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publicvoid setStartIndex(int startIndex){ S* <:He&1
if(totalCount <= 0) oBIKtS*L
this.startIndex = 0; ~9x$tb x-
elseif(startIndex >= totalCount) (8{h I
this.startIndex = indexes
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[indexes.length - 1]; o3%+FWrVTS
elseif(startIndex < 0) 'p{>zQ\5
this.startIndex = 0; 3D%I=p(
else{ Z=wLNm H
this.startIndex = indexes "rkP@ja9n
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[startIndex / pageSize]; "y5c)l(Rg
} MbjH\XRB
} x+^iEj`gk
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publicint getNextIndex(){ dZ;csc@xv
int nextIndex = getStartIndex() + 5a4;d+
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pageSize; E[e ''
if(nextIndex >= totalCount) .!=2#<
return getStartIndex(); wVw3YIN#
else _`ot||J
return nextIndex; ~
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} o- GHAQ
@u$4{sjgf\
publicint getPreviousIndex(){ #O `nQ
int previousIndex = getStartIndex() - b+3{ bE
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pageSize; ar>S_VW*
if(previousIndex < 0) g6r3V.X'
return0; / 1E6U6
else rN_\tulOF
return previousIndex; =j}]-!
} C\
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} Z>M0[DJ_
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抽象业务类 8"RX~Igf
java代码: APy&~`
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/** E}4R[6YD
* Created on 2005-7-12 o3j4XrK
*/ * UBU?
package com.javaeye.common.business; *7DQ#bD
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import java.io.Serializable; dN;C-XF3s
import java.util.List; 1;g>?18@
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import org.hibernate.Criteria; qKZ~)B j
import org.hibernate.HibernateException; Bo)w#X
import org.hibernate.Session; O`Nzn~),x
import org.hibernate.criterion.DetachedCriteria; JKXs/r;:
import org.hibernate.criterion.Projections; \JN?3}_J
import zTm&m#){3A
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org.springframework.orm.hibernate3.HibernateCallback; s#-`,jqD
import ~b\bpu
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org.springframework.orm.hibernate3.support.HibernateDaoS .k Gg}
<.+hV4,3
upport; lc#su$xR>
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import com.javaeye.common.util.PaginationSupport; "J3@Z,qW
;NBJ@E,
public abstract class AbstractManager extends jQ(qaX&
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HibernateDaoSupport { r1JKTuuo
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privateboolean cacheQueries = false; !fZ{=
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privateString queryCacheRegion; .@.O*n#K
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publicvoid setCacheQueries(boolean Gpo(Zf?
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cacheQueries){ &mp=j GR
this.cacheQueries = cacheQueries; ebp18_a|
} ixp(^>ZN
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publicvoid setQueryCacheRegion(String )lBke*j~
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queryCacheRegion){ DXsp 2
this.queryCacheRegion = 349W0>eOT
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queryCacheRegion; GUJx?V/[
} MG<F.u
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publicvoid save(finalObject entity){ yM=%a3
getHibernateTemplate().save(entity); ,J!G-?:@n
} 5@F1E8T
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publicvoid persist(finalObject entity){ &X
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getHibernateTemplate().save(entity); )zf&`T
} h/mmV:v
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publicvoid update(finalObject entity){ _.KKh62CN
getHibernateTemplate().update(entity); Uf1i"VY
} iQ~;to;Y
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publicvoid delete(finalObject entity){ .|G([O^H
getHibernateTemplate().delete(entity); vB
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} ~$Xz~#~
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publicObject load(finalClass entity, XFUlV;ek
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finalSerializable id){ T;-&3
return getHibernateTemplate().load eR$qw#%c*
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(entity, id); jhr:QS/9
} >\+c@o[
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publicObject get(finalClass entity, g+bc4eU
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finalSerializable id){ \L($;8`\
return getHibernateTemplate().get 9nu!|reS
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(entity, id); :*4b,P
} om@GH0o+
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publicList findAll(finalClass entity){ ,qz$6oxh\
return getHibernateTemplate().find("from ...|S]a
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" + entity.getName()); IlJ!jq
} nYhI0q
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publicList findByNamedQuery(finalString H$bu*o-Z
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namedQuery){ outAZy=R;
return getHibernateTemplate Q`j!$r
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().findByNamedQuery(namedQuery); jNd."[IrO
} cv})^E$x
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publicList findByNamedQuery(finalString query, !YYI{BJ7:N
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finalObject parameter){ #&u9z5ywM
return getHibernateTemplate :08b&myx
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().findByNamedQuery(query, parameter); 6jyS]($q
} [CTE"@A
+ :4
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publicList findByNamedQuery(finalString query, DyhW_PH2J
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finalObject[] parameters){ t@m!k+0
return getHibernateTemplate OMgFp |^
<Ih)h$8`
().findByNamedQuery(query, parameters); r{R879
} n] {sBI3
sl?> X)}
publicList find(finalString query){ rWsUWA T*
return getHibernateTemplate().find v/gxQy+l
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(query); &m<:&h& b
} di$\\ Ah
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publicList find(finalString query, finalObject "V|&s/9
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parameter){ as%@dUK?
return getHibernateTemplate().find 1fajTT?
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(query, parameter); >8%<ML
} CCx_|>
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public PaginationSupport findPageByCriteria Fq>tl 64A
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(final DetachedCriteria detachedCriteria){ <Cv6wC=
return findPageByCriteria p8gm=
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); \MhSIlM#
} ,,
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public PaginationSupport findPageByCriteria PiQsVk
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(final DetachedCriteria detachedCriteria, finalint f0!i<9<
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startIndex){ [{@0/5i
return findPageByCriteria B L^?1x
5=cS5q@
(detachedCriteria, PaginationSupport.PAGESIZE, L F<{/c9,
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startIndex); oJ4OVfknD
} gs/ i%O
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public PaginationSupport findPageByCriteria e 97Ll=>
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(final DetachedCriteria detachedCriteria, finalint 5ub|r0&M
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pageSize, cl,\N\
finalint startIndex){ +q<G%PwbV
return(PaginationSupport) E]@$,)nC
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getHibernateTemplate().execute(new HibernateCallback(){ ,76xa%k(U|
publicObject doInHibernate L'A9TW2
- 2DvKW$
(Session session)throws HibernateException { +wPXDN#R
Criteria criteria = ;zF3e&e(
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detachedCriteria.getExecutableCriteria(session); <A~a|A-QFR
int totalCount = r3OR7f[
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((Integer) criteria.setProjection(Projections.rowCount "/ 9EUbca
rg5ZxN|g
()).uniqueResult()).intValue(); =(aA`:Nl
criteria.setProjection qz_'v{uAj
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(null); "O (N=|b
List items = sd
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),!1B%
criteria.setFirstResult(startIndex).setMaxResults Nv[MU@Tv
L|hoA9/]
(pageSize).list(); bfV&z+Rv-5
PaginationSupport ps = i$?$X,
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new PaginationSupport(items, totalCount, pageSize, or<n[<D-C
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startIndex); 3bU(ea^e$
return ps; W[VbFsI&b
} }w_r(g?\
}, true); dilom#2l
} <@448,9&
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public List findAllByCriteria(final ovXU +8
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DetachedCriteria detachedCriteria){ d94Le/E
return(List) getHibernateTemplate tg~@(IT}j
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().execute(new HibernateCallback(){ /}kG$~
publicObject doInHibernate qdCcMcGt
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(Session session)throws HibernateException { w,)O*1't
Criteria criteria = VZ3{$0
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detachedCriteria.getExecutableCriteria(session); 1-=ZIHW
return criteria.list(); KkJrh@lk
} 93[&'
}, true); *DUP$@}k
} =:"wU
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public int getCountByCriteria(final :w,#RcW
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DetachedCriteria detachedCriteria){ my]t[%Q{
Integer count = (Integer) WeiDg,]e$b
,
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getHibernateTemplate().execute(new HibernateCallback(){ E;MelK<8(
publicObject doInHibernate ABaK60.O[O
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(Session session)throws HibernateException { CM`B0[B
Criteria criteria = =bHS@h8N<
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detachedCriteria.getExecutableCriteria(session); \9!hg(-F
return - _?U/k(Hi
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criteria.setProjection(Projections.rowCount '>:c:Tewy
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()).uniqueResult(); pf8M0,AY
} (ebC80M
}, true); `EdZ
return count.intValue(); q).["fSV
} A)%!9i)
} MBn ZO
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用户在web层构造查询条件detachedCriteria,和可选的 F%ffnEJg
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 j;yKL-ycB
p>=i'~lQ6
PaginationSupport的实例ps。 v$)ZoM6E
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ps.getItems()得到已分页好的结果集 L/c`t7
ps.getIndexes()得到分页索引的数组 /6{P
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ps.getTotalCount()得到总结果数 aN?^vW<
ps.getStartIndex()当前分页索引 ?RPVd8PUhN
ps.getNextIndex()下一页索引 csjCXT=Ve
ps.getPreviousIndex()上一页索引 ,CxIA^
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 d=C&b]
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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 *!r"+?0gN
KXf(v4
一下代码重构了。 _Kwp8_kTr
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我把原本我的做法也提供出来供大家讨论吧: kyH0J[/n
t2LX@Q"
首先,为了实现分页查询,我封装了一个Page类: cH:9@> '$a
java代码: Ay@/{RZz
83!{?EPE
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/*Created on 2005-4-14*/ ;DgQ8"f
package org.flyware.util.page; =Cc]ugl7-
(91 YHhk{
/** "lRxatM
* @author Joa e'|IRhr
* zQ#2BOx1
*/ 6L<QKE=
publicclass Page { %Y-5L;MI
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/** imply if the page has previous page */ #h}a
privateboolean hasPrePage; ;_S
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/** imply if the page has next page */ hem>@Bp'V
privateboolean hasNextPage; n{I1ZlEeh
,L=lg,lH^
/** the number of every page */ Yb\d(k$h
privateint everyPage; :/R>0 n,
t{-*@8Ke
/** the total page number */ : G'a"%x
privateint totalPage; LeV";=_n
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/** the number of current page */ Bn{i+8I
privateint currentPage; wx8Qz,Z
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/** the begin index of the records by the current WH_
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query */ watTV\b
privateint beginIndex; Vg~10Q
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k=4C"
/** The default constructor */ l5nm.i<M
public Page(){ "*LQr~k~}
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} '#a;n
&$heW,
/** construct the page by everyPage E[Q2ZqhgbP
* @param everyPage wGw<z[:f
* */ op($+Q
public Page(int everyPage){ O7oq1JI]Y
this.everyPage = everyPage; uD\rmO{
} MZ?+I~@
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/** The whole constructor */ Vn65:" O
public Page(boolean hasPrePage, boolean hasNextPage, M(1cf(<+
n_(f"Uv
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int everyPage, int totalPage, $DdC|gMK
int currentPage, int beginIndex){ R|92T*h
this.hasPrePage = hasPrePage; ;`h$xB(
this.hasNextPage = hasNextPage; i&q_h>ZTg
this.everyPage = everyPage; 8g {;o7
this.totalPage = totalPage; 'p[*2J"K4
this.currentPage = currentPage; <v!jS=T
this.beginIndex = beginIndex; 7LB%7~{<
} @KRia{
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/** 0oe2X1.%
* @return j;I(w [@P
* Returns the beginIndex. fohZ&f|>
*/ DzIV5FG
publicint getBeginIndex(){ 1)3'Y2N*
return beginIndex; Wuk!\<T{
} $Wu|4]o>9
EE*|#
/** A;k#8&;
* @param beginIndex r4ljA@L
* The beginIndex to set. u2OrH3E4E3
*/ 26p_fKY
publicvoid setBeginIndex(int beginIndex){ y@SI )&D
this.beginIndex = beginIndex; "xNP"S
} i91k0q*di
TR%8O;
/** 7m %[$X`
* @return BMtk/r/
* Returns the currentPage. shEAr*u
*/ N8DouDq
publicint getCurrentPage(){ d@tf+_Ih
return currentPage;
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} }~p%e2<
dsOt(yNo
/** ?zf3AZ9
* @param currentPage uPC(|U%
* The currentPage to set. A-, hm=?
*/ Fkg%_v$
publicvoid setCurrentPage(int currentPage){ ^Rtxef
this.currentPage = currentPage; IBUFXzl
}
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@yj~5Gf(j
/** SW5n?Qj3-
* @return >[&ser
* Returns the everyPage. d)0|Q
*/ )%<,JD
publicint getEveryPage(){ gD;T"^S+
return everyPage; 4|4 *rhwp
} e jR_3K^
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/** }=B~n0
* @param everyPage u08j9)
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* The everyPage to set. [E+J=L.l
*/ &-!$qUli
publicvoid setEveryPage(int everyPage){ l](!2a=[
this.everyPage = everyPage; Dbb=d8utE
} e}n(mq
mmG]|Cl@
/** F8#MI
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* @return i(ZzE
* Returns the hasNextPage. HCx0'|J
*/ 8Zy*#[-
publicboolean getHasNextPage(){ hgbf"J6V8
return hasNextPage; G`/4n@
} *^Ro I
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/** ~YenH
* @param hasNextPage TRJTJM_k
* The hasNextPage to set. M`7[hr
*/ n]7rHV}G
publicvoid setHasNextPage(boolean hasNextPage){ DMTc{
this.hasNextPage = hasNextPage; q#1G4l.
} |
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/** R;fe v
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* @return hL&7D@
* Returns the hasPrePage. Vk*XiEfKm>
*/ s>1\bio*I
publicboolean getHasPrePage(){ `GlOl-
return hasPrePage; !? H:?
} !1K.HdK
Ov4=!o=
/** @$Yk#N;&(
* @param hasPrePage {NcJL< ;tS
* The hasPrePage to set. VbTX;?
*/ |`pBI0Sjo
publicvoid setHasPrePage(boolean hasPrePage){ <WnIJum
this.hasPrePage = hasPrePage; I[b{*g2Zw
} F/,6Jh
"kC6G%
/** &ld<fa(w+2
* @return Returns the totalPage. :5'hd^Q
* n*i&o;5
*/ TtnJ
u*
publicint getTotalPage(){ Qmb+%z
return totalPage; ;JgSA&'e
} EQk omjv
-0BxZ AW=
/** Q&lb]U+\u
* @param totalPage )A6=P%;}>I
* The totalPage to set. &/:c?F?l
*/ .t9`e=%
publicvoid setTotalPage(int totalPage){ -ik=P]?
this.totalPage = totalPage; ^hr# 1
} Ui-Y`
4=`1C-v?q
} X$G:3uoN
r\}?HS06
etUfdZ
TXT<6(
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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 VKfpk^rU
w`r%_o-I
个PageUtil,负责对Page对象进行构造: g/WDAO?d
java代码: e>6W ^ )
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Mn3j6a
/*Created on 2005-4-14*/ Bn%?{z)
package org.flyware.util.page; *_mER`
Q[%G`;e #
import org.apache.commons.logging.Log; eu8a<
import org.apache.commons.logging.LogFactory; st~l||
^ UhqV"[7k
/** $FDGHFM
* @author Joa B.smQt
* >|gXE>
*/ 8r:T&)v
publicclass PageUtil { smn(q)tt
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privatestaticfinal Log logger = LogFactory.getLog VKw.g@BY
XR p60i6f
(PageUtil.class); lqgR4 !
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/** TKbfZw
* Use the origin page to create a new page Tr4\ `a-i
* @param page Yt{Z+.;9OI
* @param totalRecords 5\O&pz@D
* @return 6i~<,;Cn
*/ UUM:*X
publicstatic Page createPage(Page page, int ydRS\l
!,{N>{I
totalRecords){ Oiqc]4TL
return createPage(page.getEveryPage(), <0m^b#hdG
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page.getCurrentPage(), totalRecords); }6 u)wF5
} "vkM*HP
uZ@qlq8
/** !>wu7u-
* the basic page utils not including exception a+CJJ3T-
#7sxb
handler +W$uHQq
* @param everyPage -UAMHd}4
* @param currentPage <Wj/A/
* @param totalRecords TEGg)\+D>
* @return page Im};wJ&
*/ (lq%4h
publicstatic Page createPage(int everyPage, int j~=<O<P
sFvYCRw
/
currentPage, int totalRecords){ n=0^8QQ
everyPage = getEveryPage(everyPage); u-bgk(u
currentPage = getCurrentPage(currentPage); ar'VoL}
int beginIndex = getBeginIndex(everyPage, m;IKV,
{j<?+o5A
currentPage); SMU8U
int totalPage = getTotalPage(everyPage, > PL}7f&:
M1k_ldP
totalRecords); xF YHv@g
boolean hasNextPage = hasNextPage(currentPage, Xk:3w,
q$s)(D
totalPage); \f VX<L
boolean hasPrePage = hasPrePage(currentPage); ^JY:$)4["
6/p9ag]
returnnew Page(hasPrePage, hasNextPage, M?<iQxtyb}
everyPage, totalPage, .:B0(4Mj
currentPage, a3z_o)"
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beginIndex); X4Uy3 TV>
} m(5LXHJnv
MCIuP`sC|
privatestaticint getEveryPage(int everyPage){ sYSq >M
return everyPage == 0 ? 10 : everyPage; gdh|X[d
} muBl~6_mb2
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privatestaticint getCurrentPage(int currentPage){ f'7/Wj
return currentPage == 0 ? 1 : currentPage; /Tw $}8
} 74(bo\
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privatestaticint getBeginIndex(int everyPage, int z,@R jaX
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currentPage){ -- IewW
return(currentPage - 1) * everyPage; lQt,(@7]
} !:uh? RW
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privatestaticint getTotalPage(int everyPage, int B4c;/W-
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totalRecords){ Wh"xt:
int totalPage = 0; ~H[_=
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if(totalRecords % everyPage == 0) %+#l{\z
totalPage = totalRecords / everyPage; O`PQ4Q*F
else #"H<k(-Cz
totalPage = totalRecords / everyPage + 1 ; Pp4Q)2X
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return totalPage; 41rS0QAM
} &`-e; Xt
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privatestaticboolean hasPrePage(int currentPage){ })q8{Qj!
return currentPage == 1 ? false : true; S3QX{5t\
} BHNJH
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privatestaticboolean hasNextPage(int currentPage, UD5hk
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int totalPage){ u)/i$N
return currentPage == totalPage || totalPage == 'g}Q@@b
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0 ? false : true; K!-iDaVI
} z_y@4B6>}
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} ?fpI,WFu
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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。 /de~+I5AB~
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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 =;?Maexp3$
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做法如下: H4M`^r@)'
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 92*"3)
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的信息,和一个结果集List: uL~.#Y_jQ
java代码: SuBUhzR
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/*Created on 2005-6-13*/ COH>B1W@
package com.adt.bo; &