Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 XWQ `]m)
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 P:N>#G~z
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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 DR:DXJc
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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 QKB+mjMH#x
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分页支持类: :KA)4[#;W
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java代码: 9H/R@i[E
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package com.javaeye.common.util; YG8V\4
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import java.util.List; ge.>#1f}
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publicclass PaginationSupport { bhIShk[
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publicfinalstaticint PAGESIZE = 30; <FBBR2
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privateint pageSize = PAGESIZE; $p4e8j[EJ
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privateList items; *fIn<Cc
: [328X2
privateint totalCount; o{fYoBgr
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privateint[] indexes = newint[0]; f$kbb6juL
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privateint startIndex = 0;
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public PaginationSupport(List items, int f^lcw
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totalCount){ jX8)Ov5Mv
setPageSize(PAGESIZE); SO(BkxV@
setTotalCount(totalCount); w9VwZow
setItems(items); M!Ao!D[
setStartIndex(0); h
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} Nr `R3(X
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public PaginationSupport(List items, int x[0hY0 ?[M
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totalCount, int startIndex){ N<a%l J
setPageSize(PAGESIZE); d94k
setTotalCount(totalCount); sL~4~178
setItems(items); =RD>#' sUK
setStartIndex(startIndex); 6)*fr'P
} Wq<oP
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public PaginationSupport(List items, int *->*p35
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totalCount, int pageSize, int startIndex){ K;sC#9m
setPageSize(pageSize); z{\tn.67
setTotalCount(totalCount); ;5[OS8
setItems(items); { m~)~/z?
setStartIndex(startIndex); W-#DEU 7_
} Q~Mkf&s
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publicList getItems(){ jIe
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return items; &T0]tzk*,
} I@6+AU~,6
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publicvoid setItems(List items){ "q M
this.items = items; 2DFsMT>X
} WVpx
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publicint getPageSize(){ )M+po-6$1
return pageSize; V.*M;T\i
} &(Fm@ksh\
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publicvoid setPageSize(int pageSize){ l9Ol|Cb&
this.pageSize = pageSize; 4Xa]yA =
} DoQ^caa@
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publicint getTotalCount(){ c:0n/DC
return totalCount; 7,p.M)t)
} f|w;u!U(
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publicvoid setTotalCount(int totalCount){ e_Hpai<b
if(totalCount > 0){ [>a3` 0M
this.totalCount = totalCount; 96~y\X@x
int count = totalCount / j#2Xw25
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pageSize; %?].(
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if(totalCount % pageSize > 0) P8X9bW~GQ
count++; BT8)t.+pv
indexes = newint[count]; ;.sYE/ZVi
for(int i = 0; i < count; i++){ H%Vf$1/TF
indexes = pageSize * z;oia!9z
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i; hGV_K" ~I0
} B2]52Fg-"
}else{ p
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this.totalCount = 0; t{iRCj
} iZfZF
} 1T|")D
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publicint[] getIndexes(){ V~ KWy@7
return indexes; X:Wd%CHP
} lmHQ"z 3G
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publicvoid setIndexes(int[] indexes){ 2qE_SSXn
this.indexes = indexes; 'J} ?'{.
} t27UlFX
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publicint getStartIndex(){ zuN(~>YH
return startIndex; ._tEDY/1m
} | 8mWR=9fs
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publicvoid setStartIndex(int startIndex){ +8Q @R)3
if(totalCount <= 0) }(u:K}8
this.startIndex = 0; &PV%=/-J
elseif(startIndex >= totalCount) e.MyJ:eL
this.startIndex = indexes !5De?OXe
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[indexes.length - 1]; };rp25i
elseif(startIndex < 0) x1g-@{8]j
this.startIndex = 0; =dNE1rdzNa
else{ aE)1LP
this.startIndex = indexes #A4WFZ
($<&H>j0
[startIndex / pageSize]; `+< ^Svou
} "AjC2P],
} "ADI.
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publicint getNextIndex(){ Sd^I>;
int nextIndex = getStartIndex() + Cx~;oWZ
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pageSize; Dom]w.W5
if(nextIndex >= totalCount) 3s%DF,
return getStartIndex(); ^`lD w
else &8i$`6wY
return nextIndex; )=gU~UV
} .zdaY,
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publicint getPreviousIndex(){ vde!k_,wZ
int previousIndex = getStartIndex() - [[T6X9
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pageSize; -!7Z
if(previousIndex < 0) \Cq4r4'
return0; ;|XX^
else 1mtYap4
return previousIndex; e}{#VB<
} NGi)Lh|
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} a8)2I~j
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抽象业务类 AfO.D?4x
java代码: 5V(#nz
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/** -a|b.p
* Created on 2005-7-12 #w5%^HwO
*/ *"_W1}^
package com.javaeye.common.business; PtQ[({d3R
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import java.io.Serializable; =pmG.>Si
import java.util.List; g*FHZM*N9
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import org.hibernate.Criteria; }@
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import org.hibernate.HibernateException; f-i5tnh
import org.hibernate.Session; rIB./,
import org.hibernate.criterion.DetachedCriteria; T; [T`
import org.hibernate.criterion.Projections; QhTn9S:D
import 5ad@}7&
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org.springframework.orm.hibernate3.HibernateCallback; 6||%T$_;}
import ;m|N9'
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org.springframework.orm.hibernate3.support.HibernateDaoS v h)CB8
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upport; ^FNju/b
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import com.javaeye.common.util.PaginationSupport; D` cy.},L
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public abstract class AbstractManager extends # ^,8JRA
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HibernateDaoSupport { Kn1u1@&Xd
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privateboolean cacheQueries = false; elKp?YN
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privateString queryCacheRegion; |Om][z
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publicvoid setCacheQueries(boolean s^)(.e_
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cacheQueries){ 6 AY~>p
this.cacheQueries = cacheQueries; `\ nKPj
} (?T{^Hg
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publicvoid setQueryCacheRegion(String QDK }e:4q
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queryCacheRegion){ +WR'\15u
this.queryCacheRegion = 8c%N+E]
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queryCacheRegion; 0iMfyW:
} $K\;sn; |:
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publicvoid save(finalObject entity){ F2n4#b
getHibernateTemplate().save(entity); #{)mr [c|
} Qe9}%k6@E
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publicvoid persist(finalObject entity){ n0':6*oGW
getHibernateTemplate().save(entity); `'(@"-L:7
} fgo3Gy*#
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publicvoid update(finalObject entity){ CX{M@x3m
getHibernateTemplate().update(entity); `J{{E,y
@
} axXR-5c
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publicvoid delete(finalObject entity){ ^#w9!I{4.
getHibernateTemplate().delete(entity); 54s90
} 7=wQ#bq"1P
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publicObject load(finalClass entity, 3Dh{#"88
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finalSerializable id){ oO;<$wx2t
return getHibernateTemplate().load $qoal
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(entity, id); #Oa`P
} ,mD$h?g
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publicObject get(finalClass entity, z3 fU|*_c
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finalSerializable id){ Yka>r9wr
return getHibernateTemplate().get %we! J%'Y]
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(entity, id); PXDJ[Oj7(0
} &b19s=Z,
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publicList findAll(finalClass entity){ #
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return getHibernateTemplate().find("from 7'{Y7]+z+
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" + entity.getName()); ~~,#<g[
} g*%o%Lv
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publicList findByNamedQuery(finalString 3"6-X_
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namedQuery){ Wb{8WPS
return getHibernateTemplate <+`}:
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().findByNamedQuery(namedQuery); niCq`!
} W TC/mcS
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publicList findByNamedQuery(finalString query, qd
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finalObject parameter){ 04#r'UIF
return getHibernateTemplate ZV:0:k.x
*3y:Wv T>
().findByNamedQuery(query, parameter); h{VGhkU9f
} EMS$?"K
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publicList findByNamedQuery(finalString query, Ktf lbI!
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finalObject[] parameters){ [V,f@}m
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return getHibernateTemplate r1xhplHH@
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().findByNamedQuery(query, parameters); AkV8}>G?#A
} v6KF0mqA&
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publicList find(finalString query){ 'uF"O"*
return getHibernateTemplate().find 2NqO,B|R
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(query); 6y)NH 8l7
} GMoE,L
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publicList find(finalString query, finalObject JXF@b-c
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parameter){ ]s:%joj%^
return getHibernateTemplate().find W&0KO-}ot
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(query, parameter); p EbyQ[
} <>6 DPHg~
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public PaginationSupport findPageByCriteria ,hXhcfFl
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(final DetachedCriteria detachedCriteria){ qCgoB 0
return findPageByCriteria :/'oh]T|
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); "~/O>.p
} JQ]A"xTIa*
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public PaginationSupport findPageByCriteria Q !G^CG
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(final DetachedCriteria detachedCriteria, finalint $[DSe~
*.F4?i2D
startIndex){ $fl+l5?9
return findPageByCriteria "Z*u2_ H
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(detachedCriteria, PaginationSupport.PAGESIZE, 80;^]l
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startIndex); &F#K=R| .j
} &)v}oHy,m
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public PaginationSupport findPageByCriteria E+e:UBeUV
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(final DetachedCriteria detachedCriteria, finalint \t^h|<`
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pageSize, Y]6kA5
finalint startIndex){ C4^o=
6{
return(PaginationSupport) /[RO>Z9
H$={i$*,Y
getHibernateTemplate().execute(new HibernateCallback(){ ErXzKf
publicObject doInHibernate _?QVc0S!
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(Session session)throws HibernateException { *'jI>^o
Criteria criteria = wY6m^g$h3
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detachedCriteria.getExecutableCriteria(session); dcbE<W#ss
int totalCount = {kNV|E
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((Integer) criteria.setProjection(Projections.rowCount H^r;,Q$9
@\s*f7
()).uniqueResult()).intValue(); -b$m<\0*
criteria.setProjection 5l[&-:(Lh
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(null); Q.Xs%{B
List items = e-Ma8+X\
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criteria.setFirstResult(startIndex).setMaxResults K|sk]2.
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(pageSize).list(); "cD MFu
PaginationSupport ps = 7w51UmO
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new PaginationSupport(items, totalCount, pageSize, :^H2D=z@
5-?*Boi>i
startIndex); Q"F" 13
return ps; &5d~ODO
} ve f9*u`
}, true); z,xGjSP
} hh7unHt-
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public List findAllByCriteria(final oF L7dL
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DetachedCriteria detachedCriteria){ n4InZ!)
return(List) getHibernateTemplate <\`qRz0/
jT=fq'RK
().execute(new HibernateCallback(){ x,M8NTb*
publicObject doInHibernate Tnoy#w}Ve
s
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(Session session)throws HibernateException { >["X(%&w
Criteria criteria = B]u !BBjC
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detachedCriteria.getExecutableCriteria(session); _qa9wK/
return criteria.list(); 9%Qlg4~<s
} W$xW9u8@+(
}, true); YHzP/&0
} $O_{cSKg7
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public int getCountByCriteria(final i5cK5MaD
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DetachedCriteria detachedCriteria){ %>-?oor
Integer count = (Integer) 7:e5l19 uI
@%BsQm
getHibernateTemplate().execute(new HibernateCallback(){ c2Wp 8l
publicObject doInHibernate uj:1_&g
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(Session session)throws HibernateException { MO%+rf0~w
Criteria criteria = \+j:d9?
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detachedCriteria.getExecutableCriteria(session); ~9Qd83`UH
return N\anjG
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criteria.setProjection(Projections.rowCount SZvp%hS0
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()).uniqueResult(); *Hz]<b?
} f4Ob4ah!(
}, true); o.(Gja4
return count.intValue(); dU-nE5
} {r%T_BfY
} 7%Ou6P$^fr
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用户在web层构造查询条件detachedCriteria,和可选的 k$GtzjN
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 "U/yq
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PaginationSupport的实例ps。 <G'M/IR a
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ps.getItems()得到已分页好的结果集 3$S~!fh
ps.getIndexes()得到分页索引的数组 9/_~YY=/h
ps.getTotalCount()得到总结果数 EQ.K+d*K][
ps.getStartIndex()当前分页索引 l#~pK6@W
ps.getNextIndex()下一页索引 nok-![
ps.getPreviousIndex()上一页索引 ICiGZ'k
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Ahc9HA2
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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 zI\+]U'
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一下代码重构了。 ?C- ju8]|
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我把原本我的做法也提供出来供大家讨论吧: `:C2Cj
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首先,为了实现分页查询,我封装了一个Page类: T$<yl#FY
java代码: b
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/*Created on 2005-4-14*/ 4j8$&~/
package org.flyware.util.page; hiEYIx
1wm`a
/** xkU8(=
* @author Joa slhMvHOk-
* 7t1as.
*/ i"xV=.
publicclass Page { jgS3#
K|l}+:k
/** imply if the page has previous page */ VN(*m(b
privateboolean hasPrePage; C"$~w3A k
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/** imply if the page has next page */ ; O(M l }z
privateboolean hasNextPage; jD%|@ux
g"k4Z
/** the number of every page */ w/"vf3}(9
privateint everyPage; TZ `Ypi7r
5423Ky<
/** the total page number */ ^G2M4+W|
privateint totalPage; !tcz_%
5Zd oem
/** the number of current page */ o"FR%%
privateint currentPage; cTS.yN({G
>*opE I+
/** the begin index of the records by the current e&*b{>1*
5!cp^[rGL
query */ TUz4-Pd
privateint beginIndex; RwYFBc
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/** The default constructor */ FRajo~H
public Page(){ ^,mN-.W
4(VV@:_%
} "(vK.-T
qp/1tC`
/** construct the page by everyPage [z ]P5
* @param everyPage U#]J5'i
* */ &M@c50&%
public Page(int everyPage){ WJu(,zM?G
this.everyPage = everyPage; *9uNM@7&0
} ~*"ZF-c,
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/** The whole constructor */ L\UGC%]9
public Page(boolean hasPrePage, boolean hasNextPage, bmK
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int everyPage, int totalPage, *4NY"EwjN
int currentPage, int beginIndex){ `e~i<Pi
this.hasPrePage = hasPrePage; Bpm COA
this.hasNextPage = hasNextPage; qg=`=]j
this.everyPage = everyPage; cTzR<Yr
this.totalPage = totalPage; uR{)%udu
this.currentPage = currentPage; i{TPf1OY`M
this.beginIndex = beginIndex; /*{'p!?
} 88,hza`#V
c0o Z7)*}
/** HR"clD\{Di
* @return D_0sXIbg
* Returns the beginIndex. ]'[:QGr
*/ DbLo{mFEIj
publicint getBeginIndex(){ L.yM"
return beginIndex; iu(obmh/o
} X-fWdoN @-
utuWFAGn A
/** }2LWDQ;po
* @param beginIndex 1fMV$T==K
* The beginIndex to set. `^[Tu 1
*/ kP+,x H)1
publicvoid setBeginIndex(int beginIndex){ q[W6I9
this.beginIndex = beginIndex; $Wj{B@k
} &V$cwB
>'W,8F
/** u&uFXOc'
* @return z9 Ch %A{
* Returns the currentPage. {l!{b1KJ
*/ ?%$O7_ThvA
publicint getCurrentPage(){ 6xtgnl#T
return currentPage; 3IQI={:k|D
} K$,<<hl
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/** Pg:xC9w4
* @param currentPage f3G:J<cL
* The currentPage to set. gBhX=2%
*/ HVoPJ!K3
publicvoid setCurrentPage(int currentPage){ poW%F zj
this.currentPage = currentPage; \By_mw
} i6k6l%
TMY. z
/**
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* @return =TNFAt
* Returns the everyPage. J/K~8sc
*/ XZ]ji9'
publicint getEveryPage(){ `<d.I%}
return everyPage; ru2M"]T
} C.:S@{sK
"Y L^j~A
/** $Z]@N
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* @param everyPage ,)*[Xa_n
* The everyPage to set. \3^V-/SJf
*/ sV2D:%\K:
publicvoid setEveryPage(int everyPage){ !9NF@e'&!
this.everyPage = everyPage; frPQi{u$
} y[.lfW?)
WHBGhU
/** syg{qtBz^
* @return |3E|VGm~
* Returns the hasNextPage. X$\CC18
*/ )e'F[
publicboolean getHasNextPage(){ [<U=)!Swg
return hasNextPage; <";1[A%7<
} [Z2[Iy
CSoVB[vS
/** @OT$* Qh
* @param hasNextPage fi>.X99(G
* The hasNextPage to set. Io JI|lP
*/ +JC"@
publicvoid setHasNextPage(boolean hasNextPage){ ]5QXiF8`
this.hasNextPage = hasNextPage; $$.q6
} $mKExW
^.)0O3oC
/** |-{e!&
* @return ktynIN
* Returns the hasPrePage. C4ktCN
*/ ;%
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publicboolean getHasPrePage(){ u? >x
return hasPrePage; D:j5/ *
} m%})H"5
"O9n|B
/** *2-b&PQR{
* @param hasPrePage ^
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* The hasPrePage to set. rp<~=X
*/ %hBwc#^
publicvoid setHasPrePage(boolean hasPrePage){ 8r"-3<*
this.hasPrePage = hasPrePage; }z/%b<o_
} %7`eT^
U_'M9g{,<
/** q%q+2P>
* @return Returns the totalPage. n+&8Uk
* U&
*/ =&k[qqxg
publicint getTotalPage(){ `5oXf
return totalPage; >)NS U
} Q6URaw#Yt`
A7#nBHwxZ
/** LU8[$.P
* @param totalPage j~.tyxOq#
* The totalPage to set. }BT0dKx
*/ QX}JQ<8
publicvoid setTotalPage(int totalPage){ rrE f<A}
this.totalPage = totalPage; N$t<&5+
} Tr}XG
A2L"&dl
} c+z [4"rYL
l+&DBw[
Mr4,?Z&`-d
' e!WZvr
N8kNi4$mp=
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 9a+Y )?z
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个PageUtil,负责对Page对象进行构造: cVMRSp
java代码: UEx<;P8rP
xj8z*fC;
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/*Created on 2005-4-14*/ noz1W ]
package org.flyware.util.page; T4}Wg=UKg
/+`%u&<
import org.apache.commons.logging.Log; (xTGt",_Jo
import org.apache.commons.logging.LogFactory; %LmsywPPp
!"RRw&0M
/** e9/Mjq\
* @author Joa :/$_eg0A
* umnQ$y
0
*/ 1k)pJzsc
publicclass PageUtil { `J03t\
#l- 0$
privatestaticfinal Log logger = LogFactory.getLog t54?<-
I][&*V1
(PageUtil.class); R)SY#*Y
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/** >O
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* Use the origin page to create a new page [\h?mlG?
* @param page yVXVH CB
* @param totalRecords [~\]<;;\
* @return L{r 4hL [
*/ / bH2Z
publicstatic Page createPage(Page page, int v)gMNzt
0&Ftx%6%
totalRecords){ ;&}z
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return createPage(page.getEveryPage(), /~;!Ew|q
$-t@=N@vO?
page.getCurrentPage(), totalRecords); FAM:; F30
} d2gYBqag
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/** i_r708ep6
* the basic page utils not including exception
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u=]*,,5<
handler !=*8*?@
* @param everyPage ;Sg.E8
* @param currentPage ]yqE6Lf9
* @param totalRecords 9c,/490Q
* @return page _
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%
*/ gCG#?f
publicstatic Page createPage(int everyPage, int 5=#d#dDc
W+"^! p|
currentPage, int totalRecords){ 6~W@$SP,F
everyPage = getEveryPage(everyPage); QE)zH)(
currentPage = getCurrentPage(currentPage); h.ftl2>
int beginIndex = getBeginIndex(everyPage, -D=Sj@G
+'olC^?5 }
currentPage); aTeW#:m
int totalPage = getTotalPage(everyPage, +> !nqp
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totalRecords); ?jlz:Z4
boolean hasNextPage = hasNextPage(currentPage, 4E=v)C'
=dKjTBR S'
totalPage); {en'8kS
boolean hasPrePage = hasPrePage(currentPage); $,, PF/N8c
>JS^yVk
returnnew Page(hasPrePage, hasNextPage, W~D_+[P|_
everyPage, totalPage, 457{9k
currentPage, y<Xu65
LFHJj-nk
beginIndex); j"h/v7~
} -XCs?@8EQ
6V JudNA
privatestaticint getEveryPage(int everyPage){ ug2W{D
return everyPage == 0 ? 10 : everyPage; N\|z{vn
} t&{;6MiE
j+ -r(lZ
privatestaticint getCurrentPage(int currentPage){ N=2T~M 1
return currentPage == 0 ? 1 : currentPage; 2y^:T'p
} [tfB*m5
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privatestaticint getBeginIndex(int everyPage, int
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currentPage){ Ta?}n^V?;
return(currentPage - 1) * everyPage; DWKQ>X6
} HFy9b|pjy
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privatestaticint getTotalPage(int everyPage, int jD9u(qAlH
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totalRecords){ JJ?rVq1g
int totalPage = 0; naf ~#==vc
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if(totalRecords % everyPage == 0) Fk 3(( n=
totalPage = totalRecords / everyPage; /v5A)A$7
else 3[fm|aU
totalPage = totalRecords / everyPage + 1 ; LPt9+sauf1
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return totalPage; ")uKDq
} $ -1ajSVJ
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privatestaticboolean hasPrePage(int currentPage){ 9Tt%~m^
return currentPage == 1 ? false : true; <5z!0m-G
} m#RJRuZ|2V
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privatestaticboolean hasNextPage(int currentPage, 96V8R<
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int totalPage){ BkXv4|UE
return currentPage == totalPage || totalPage == )x/#sW%)
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0 ? false : true; *2a" 2o
}
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} X13+n2^8]
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=figat
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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。 ]z^jz#>um&
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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 o-RZwufZ`
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做法如下: F-|DZ?)k5
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 .2JZ7
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的信息,和一个结果集List: G^)]FwTs
java代码: }5vKQf
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/*Created on 2005-6-13*/ Vp]7n!g4l
package com.adt.bo; 1iz =i^}
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import java.util.List; \UK}B
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import org.flyware.util.page.Page; #1J,!seJ
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/** *x2!N$b
* @author Joa j67a?0<C2U
*/ 7/<~s]D[%
publicclass Result { ,byc!P
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private Page page; K@1gK<,a
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private List content; P
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/** $||WI}k3V
* The default constructor n+=qT$w)
*/ tP|/Q5s
public Result(){ M(+Pd_c6
super(); "7%jv[
} O"~[njwkE
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/** m^L !_~
* The constructor using fields |E6_TZ#=
* V6dq8Z"h
* @param page K9xvog
* @param content cL#-vW<s3
*/ 2EM6k|l5
public Result(Page page, List content){ <1I4JPh>x
this.page = page; Fvk=6$d2
this.content = content; vcQl0+&
} 3mU~G}ig
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/** 4$VDJ
* @return Returns the content. X9?)P5h=
*/ %(
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publicList getContent(){ 5;KJ0N*-
return content; Rnwm6nu
} <Mvniz
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/** \ejHM}w3,
* @return Returns the page. i;{lY1
*/ V.
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public Page getPage(){ h9 DUS,G9,
return page; &