Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ?!U[~Gq
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 zTw"5N
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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 TB!I
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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 mOsp~|d
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分页支持类: d}[cX9U/
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java代码: 0
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package com.javaeye.common.util; =Xh)34q
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import java.util.List; W-=6:y#A
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publicclass PaginationSupport { U%nkPIFm
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publicfinalstaticint PAGESIZE = 30; =1l6(pJ
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privateint pageSize = PAGESIZE; ixdsz\<
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privateList items; :CyHo6o9
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privateint totalCount; (jM0YtrD
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privateint[] indexes = newint[0]; o8bd L<
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privateint startIndex = 0; a[-!X7,IU
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public PaginationSupport(List items, int 0@
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totalCount){ %c }V/v_h
setPageSize(PAGESIZE); tJ\
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setTotalCount(totalCount); ysW})#7X
setItems(items); {{?g%mQ6
setStartIndex(0); lK0ny>RB
} 7zb^Z]
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public PaginationSupport(List items, int zR" cj
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totalCount, int startIndex){ 2%W;#oi?
setPageSize(PAGESIZE); m9 h '!X<
setTotalCount(totalCount); VfX^iG r
setItems(items); m@td[^O-
setStartIndex(startIndex); $9)os7H7
} 4b8G 1fm
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public PaginationSupport(List items, int 'NEl`v*<P
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totalCount, int pageSize, int startIndex){ vrnvv?HPrR
setPageSize(pageSize); Hr|f(9xA
setTotalCount(totalCount); oP&/>GmXL
setItems(items); ?b
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setStartIndex(startIndex); X0lPRk53(
} A~?M`L>B
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publicList getItems(){ hsC T:1i
return items;
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} Pq;OShU_
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publicvoid setItems(List items){ 2HE@!*z9H
this.items = items; AkhG~L
} Bn}woyJdx
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publicint getPageSize(){ 3Z!%td5n
return pageSize; ov6xa*'a
} ul~ux$a
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publicvoid setPageSize(int pageSize){ z$~x 2<
this.pageSize = pageSize; 3_(_yEKx
} SyWZOE%p
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publicint getTotalCount(){ LP2~UVq
return totalCount; GEc6;uz<
} Q+:y
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publicvoid setTotalCount(int totalCount){ pSs*Z6c)@
if(totalCount > 0){ ]3KeAJ
this.totalCount = totalCount; eV9U+]C`
int count = totalCount / O)'CU1vMb
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pageSize; ~tDYo)hH8
if(totalCount % pageSize > 0) FuhmLm'p
count++; g'"~'
indexes = newint[count]; Qb536RpcTY
for(int i = 0; i < count; i++){
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indexes = pageSize * Q:}]-lJg
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} -F 5BJk
}else{ b8mH.g&l
this.totalCount = 0; 9vI~vl l
} $7x2TiAL
} Cf%
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publicint[] getIndexes(){ :eN&wQ5q
return indexes; .u-a+ac<
} VkQ@c;C
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publicvoid setIndexes(int[] indexes){ '{&Q&3J_
this.indexes = indexes; qZ1'uln=C-
} eqx }]#
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publicint getStartIndex(){ 2W AeSUX
return startIndex; FI.te3i?7
} H$![]Ujq
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publicvoid setStartIndex(int startIndex){ 7;>|9k
if(totalCount <= 0) \8vP"Kr
this.startIndex = 0; Q\Ek U.[I
elseif(startIndex >= totalCount) Ailq,c
this.startIndex = indexes zsL@0]e&
'I[?R&j$G
[indexes.length - 1]; P9v(5Z00|d
elseif(startIndex < 0) lY%I("2=
this.startIndex = 0; MAh1tYs4D
else{ dN8Mfa)
this.startIndex = indexes @G5T8qwN
> 0^<<=m
[startIndex / pageSize]; hD6BP
} C'6I< YX
} ;[ <(4v$
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publicint getNextIndex(){ )Sn0Y B
int nextIndex = getStartIndex() + =uP?
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pageSize; 3?Pg
;
if(nextIndex >= totalCount) o'2eSm0H
return getStartIndex(); !%>RHh[
else =p5DT
return nextIndex; p-4$)w~6i
} c^}y9% 4c
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publicint getPreviousIndex(){ ]!/
int previousIndex = getStartIndex() - .}IW!$
dq
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pageSize; +x]/W|5
if(previousIndex < 0) 3$?6rMl@y
return0; $*q|}Tvl#
else dq93P%X24
return previousIndex; t2[/eM.G
} 4'QX1p
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} 7^dr[.Q[*
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抽象业务类 /U;j-m&
java代码: ifDWN*k6
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/** \.L jA_
* Created on 2005-7-12 :nx+(xgw
*/ >@vu;j\*E5
package com.javaeye.common.business; J(]|)?x2
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import java.io.Serializable; E)-;sFz
import java.util.List; q?!HzZ
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import org.hibernate.Criteria; 2!#g\"
import org.hibernate.HibernateException; q T6y&
import org.hibernate.Session; /4x\}qvU
import org.hibernate.criterion.DetachedCriteria; C19N0=
import org.hibernate.criterion.Projections; 0qS/>u*
import D ,kxB~
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org.springframework.orm.hibernate3.HibernateCallback; 5r5on#O&
import | 6{JINW
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org.springframework.orm.hibernate3.support.HibernateDaoS p%DU1+SA
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upport; !v8R(
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import com.javaeye.common.util.PaginationSupport; u@Hz7Q}
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public abstract class AbstractManager extends 0YiTv;mq;
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HibernateDaoSupport { )Rn\6ka
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privateboolean cacheQueries = false; o;@~uU
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privateString queryCacheRegion; O>L,G)g
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publicvoid setCacheQueries(boolean }H
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cacheQueries){ p{,#H/+J
this.cacheQueries = cacheQueries; <tvLKx
} Ar<5UnT
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publicvoid setQueryCacheRegion(String r^5%0_F]
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queryCacheRegion){ F^GNOD3J
this.queryCacheRegion = [xiqlb,8
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queryCacheRegion; lTC0kh
} '~Y@HRVL@|
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publicvoid save(finalObject entity){ `df!-\#
getHibernateTemplate().save(entity); 26p[x'W
}
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publicvoid persist(finalObject entity){ 1^|#QMT
getHibernateTemplate().save(entity); 0si1:+t-[+
} d.?}>jl
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publicvoid update(finalObject entity){ pg%(6dqK4
getHibernateTemplate().update(entity); =mXC,<]
} G QYR`;>
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publicvoid delete(finalObject entity){ ^=eC1bQA
getHibernateTemplate().delete(entity); b-
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} OKh0m_ )7
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publicObject load(finalClass entity, %T]$kF++&
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finalSerializable id){ Ry>y
return getHibernateTemplate().load F` 7v
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(entity, id); WO.u{vW]'
} bL
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publicObject get(finalClass entity, 7?yS>(VmT
#][i!9$
finalSerializable id){ *b>RUESF
return getHibernateTemplate().get p{5m5x
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(entity, id); O q$_ q
} Tc(=J7*r&
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publicList findAll(finalClass entity){ JwbZ`Z*w
return getHibernateTemplate().find("from Hk*1Wrs*
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" + entity.getName()); cTGd<
} fk,Vry
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publicList findByNamedQuery(finalString $A?9U}V#^
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namedQuery){ \'Ae,q|w
return getHibernateTemplate U,P>P+\@
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().findByNamedQuery(namedQuery); 9" q-Bb
} AY5iTbL1
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publicList findByNamedQuery(finalString query, KFbB}oId
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finalObject parameter){ |BFzTz,o
return getHibernateTemplate x.-d)]a!
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().findByNamedQuery(query, parameter); y2I7Zd .
} mxqD'^n#
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publicList findByNamedQuery(finalString query, Sy VGm@
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finalObject[] parameters){ ! $$>D"
return getHibernateTemplate s A,bR|
m}'_Poc
().findByNamedQuery(query, parameters); hiS|&5#
} nq{/fD(2
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publicList find(finalString query){ g[G/If
return getHibernateTemplate().find 2#7|zhgb
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(query); W q<t+E[
} nW)+-Wxq
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publicList find(finalString query, finalObject ]B3](TH"
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parameter){ =#u4^%i)
return getHibernateTemplate().find :gV~L3YW5
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(query, parameter); Y$L`
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} B2[f1IMI
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public PaginationSupport findPageByCriteria 57q=
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(final DetachedCriteria detachedCriteria){ NTt4sWP!I
return findPageByCriteria 4"2%mx:
Be|! S_Y P
(detachedCriteria, PaginationSupport.PAGESIZE, 0); Gk~aTO
} kD#n/RBgf
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public PaginationSupport findPageByCriteria WPRk>j
q8$t4_pF
(final DetachedCriteria detachedCriteria, finalint "\@J0|ppb
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startIndex){ B!Wp=9)G
return findPageByCriteria Ixn|BCi60A
CC=I|/mBM
(detachedCriteria, PaginationSupport.PAGESIZE, ^# $IoW
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startIndex); Yd3lL:M
} o:#jvi84F
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public PaginationSupport findPageByCriteria &MpLm&
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(final DetachedCriteria detachedCriteria, finalint c
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pageSize, 0Ye/
finalint startIndex){
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return(PaginationSupport) us.[wp'Sh
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getHibernateTemplate().execute(new HibernateCallback(){ 0cG[<\qT
publicObject doInHibernate `e ZDG
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(Session session)throws HibernateException { c$1u
Criteria criteria = 9C \}bT
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detachedCriteria.getExecutableCriteria(session); YA,.C4=s
int totalCount = s#5#WNzP
m u9,vH
((Integer) criteria.setProjection(Projections.rowCount gR!hN.I
8(n>99VVK
()).uniqueResult()).intValue(); }m<+tn3m
criteria.setProjection M;XU"8
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(null); Y"t|0dO%b
List items = oPs asa
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criteria.setFirstResult(startIndex).setMaxResults =A5i84y.2u
VJ#ys_W
(pageSize).list(); Lf9s'o}.R
PaginationSupport ps = ozsd6&z5l
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new PaginationSupport(items, totalCount, pageSize, (;g/wb:
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startIndex); c*#$sZ@YA
return ps; roZn{+f
} `%|3c
}, true); b6;MTz*k>
} j(I(0Yyh
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public List findAllByCriteria(final MX*4d{ l
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DetachedCriteria detachedCriteria){ ug}u>vQ>
return(List) getHibernateTemplate Eva&FHRTY
@[FO;4w
().execute(new HibernateCallback(){ wy|b Hkr_
publicObject doInHibernate O\q6T7bfRW
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(Session session)throws HibernateException { @=g{4(zR^
Criteria criteria = KD\%B5Jy
Y A+R!t:F{
detachedCriteria.getExecutableCriteria(session); kb$Yc)+R4
return criteria.list(); ~Q^.7.-T
} ~2[kCuu
}, true); BSkmFd(*
} I7h v'3u
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public int getCountByCriteria(final - ]/=WAOK
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DetachedCriteria detachedCriteria){ ?Z!R
Integer count = (Integer) ?W dY{;&
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getHibernateTemplate().execute(new HibernateCallback(){ eF0FQlMe[
publicObject doInHibernate D
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(Session session)throws HibernateException { e~he#o[%a
Criteria criteria = Y ajAz5N
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detachedCriteria.getExecutableCriteria(session); u>] )q7s
return @G>eCj
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criteria.setProjection(Projections.rowCount b5~p:f-&4B
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()).uniqueResult(); `uDOIl
} mq}uq9<
}, true); .2|(!a9W
return count.intValue(); _/ 5
} ~4#D
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} 6c>:h)?
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用户在web层构造查询条件detachedCriteria,和可选的 [Ak0kH>
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 @tRDKPh
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PaginationSupport的实例ps。 z t
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ps.getItems()得到已分页好的结果集 Q4L7{^[X
ps.getIndexes()得到分页索引的数组 EIpz-"S
ps.getTotalCount()得到总结果数 YJDJj
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ps.getStartIndex()当前分页索引 mTL`8hv?
ps.getNextIndex()下一页索引 JCB3 BZg7&
ps.getPreviousIndex()上一页索引 g^#,!e
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 }:s.m8LC5n
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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 3/c%4b.Z
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一下代码重构了。 x lsAct:
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我把原本我的做法也提供出来供大家讨论吧: B oiS
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首先,为了实现分页查询,我封装了一个Page类: HqyAo]{GN
java代码: wT,=C'
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/*Created on 2005-4-14*/ ]1[:fQF7/L
package org.flyware.util.page; P*ZMbAf.
*
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/** >$a;+v
* @author Joa X]W(
* ]$-<< N{}'
*/ "kVzN22
publicclass Page { #D ]CuSi
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/** imply if the page has previous page */ m !i`|]m
privateboolean hasPrePage; bFH`wLW
-I;\9r+
/** imply if the page has next page */ 5e?<x>e
privateboolean hasNextPage; `9T5Dem|#
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/** the number of every page */ Nz;\PS
privateint everyPage; VZ
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/** the total page number */ &zP>pQr`#
privateint totalPage; $Fy>N>,E(
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/** the number of current page */ EP+LK?{%
privateint currentPage; _w'_l>I
9}4~3_gv;M
/** the begin index of the records by the current ":GC}VIS
*{\))Zmhd
query */ Y zmMF
privateint beginIndex; uotW[L9
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dt"&
/** The default constructor */ <num!@2D
public Page(){ ~mMTfC~9
ojA !!Ru
} ]M'~uTf
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/** construct the page by everyPage 33&\E- Q>
* @param everyPage j5]ul!ji
* */ j9vK~_?;
public Page(int everyPage){ Mq'm
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this.everyPage = everyPage; hr hj4
} TNK1E
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/** The whole constructor */ :3b02}b7
public Page(boolean hasPrePage, boolean hasNextPage, (vvD<S*
9QL%q;
#
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int everyPage, int totalPage, :M<] 6o
int currentPage, int beginIndex){ 1uB$@a\
this.hasPrePage = hasPrePage; MX.?tN#F|H
this.hasNextPage = hasNextPage; S2nX{=
this.everyPage = everyPage; "^;h'
this.totalPage = totalPage; 5K)_w:U
X
this.currentPage = currentPage; LIQ].VxIs
this.beginIndex = beginIndex; ;K%/sIIke
} <^_crJONom
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/** ='m%Iq7X
* @return ?)(-_N&T
* Returns the beginIndex. %H,s~IU
*/ n=AcN
publicint getBeginIndex(){ jIVD i~Ld
return beginIndex; 3wcFR0f
} VxARJ*4=Y
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/** R^P>yk8
* @param beginIndex As`=K$^Il.
* The beginIndex to set. 4l68+
*/ Id>4fF:o
publicvoid setBeginIndex(int beginIndex){ Ym!e}`A\F
this.beginIndex = beginIndex; zNdkwj p+
} j0V/\Ep)T<
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/** ela^L_N hF
* @return G -+!h4p
* Returns the currentPage. 85;bJfY
*/ ( }Bb=~
publicint getCurrentPage(){ x\f~Gtt7Y
return currentPage; w>=N~0@t
} P)J-'2{
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/** hpPacN
* @param currentPage WvSm!W
* The currentPage to set. y_=y%
*/ aekke//y
publicvoid setCurrentPage(int currentPage){ 0<NS1y
this.currentPage = currentPage; g$?^bu dxv
} g= Vu'p 3u
UeLO `Ug0;
/** EwA*
* @return wK#*|
* Returns the everyPage. [H>u'fy:C
*/ m m`#v
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publicint getEveryPage(){ \y]K]iv
return everyPage; :Ev
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} >RAg63!`
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/** L-C^7[48=
* @param everyPage j&'6|s{
* The everyPage to set. o,dp{+({
*/ X )tH23
publicvoid setEveryPage(int everyPage){ f!w/zC .
this.everyPage = everyPage; 5)lcgvp
} k'#3fz\
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x:
/** C9sU^]#F
* @return ]Z8u0YtM)
* Returns the hasNextPage. pTwzVz~
*/ &um++
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publicboolean getHasNextPage(){ e8^/S^ =&d
return hasNextPage; vf{$2rC
} 8TT#b?d
u@ #%SX
/** phjM(lmCo
* @param hasNextPage LkS tU)
* The hasNextPage to set. {/,(F^T>2
*/
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publicvoid setHasNextPage(boolean hasNextPage){ f/UU{vX(
this.hasNextPage = hasNextPage; j;]I
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} W6NhJ#M7
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/** yj4"eDg]
* @return @gK`RmhGE5
* Returns the hasPrePage. =JzzrM|V*
*/ w+
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publicboolean getHasPrePage(){ -EP1Rl`\
return hasPrePage; 92<+ug =
} Za|iU`e\
]?@ [Ny=0
/** 20|_wAA5
* @param hasPrePage AYfOETz
* The hasPrePage to set. cLf90|YFp
*/ s_NY#MPz[
publicvoid setHasPrePage(boolean hasPrePage){ h@$SJe(hl
this.hasPrePage = hasPrePage; M> WWP3
} [S,$E6&j$"
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/** O~V^]
* @return Returns the totalPage. ~Yk^(hl2
* %"mI["{
*/ )
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publicint getTotalPage(){ w gS'/
return totalPage; $\J5l$tU
} NgyEy n
\
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/** Ip{R'HG/
* @param totalPage d9v66mpJM
* The totalPage to set. u>lt}0
*/ jSE)&K4nI
publicvoid setTotalPage(int totalPage){ D}y W:Pi'
this.totalPage = totalPage; -fA =&$V
} pV ^+X}
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} vlkwWm
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 '/8/M{`s
rk1,LsZVS
个PageUtil,负责对Page对象进行构造: iuY,E
java代码: GO"|^W
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/*Created on 2005-4-14*/ L3Y,z3/
package org.flyware.util.page; <)T| HKx
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import org.apache.commons.logging.Log; 2QaE&8vW
import org.apache.commons.logging.LogFactory; I9qZE=i
6a,8t
/** (%L/|F_
* @author Joa BQPmo1B
* gDU!dT
*/ _|M8xI
publicclass PageUtil { HZ'rM5Kq
^.LB(GZ,
privatestaticfinal Log logger = LogFactory.getLog BZW03e8|
V _~lME
(PageUtil.class); ?]D&D:Z?I
j ^j"w(a
/** v>`Fo[c
* Use the origin page to create a new page t~ {O)tt
* @param page y5eEEG6
* @param totalRecords Ds(Z.
* @return bSw^a{~)
*/ ir}z^+
publicstatic Page createPage(Page page, int D{JjSky
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totalRecords){ Q O =5Q
return createPage(page.getEveryPage(), n{TWdC
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page.getCurrentPage(), totalRecords); O;RBK&P
} 4ekwmw(ox
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/** Xsa8YP9
* the basic page utils not including exception 'EIe5Op
b_ TI_
handler f\oW<2k]~
* @param everyPage 60%nQhb
* @param currentPage a9e0lW:=c
* @param totalRecords :8@)W<>%
* @return page E&cC2(w
*/ 9jI muSZ
publicstatic Page createPage(int everyPage, int bX2BEa8<"
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currentPage, int totalRecords){ .Qrpz^wdt
everyPage = getEveryPage(everyPage); nV8'QDQ:Al
currentPage = getCurrentPage(currentPage); mBwz.KEm<
int beginIndex = getBeginIndex(everyPage, sf2%WPK
EY"of[p
currentPage); V$hL\`e
int totalPage = getTotalPage(everyPage, "mBM<rEn*
mQ`atFz:Z
totalRecords); S'HA]
boolean hasNextPage = hasNextPage(currentPage, DRm`y>.
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totalPage); Ew0)MZ.#
boolean hasPrePage = hasPrePage(currentPage); 3}\ z&|
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returnnew Page(hasPrePage, hasNextPage, h.R46 :
everyPage, totalPage, 5!A:xV]6]
currentPage, K@=u F1?
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beginIndex); c!\T0XtT
} !k%
PP
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privatestaticint getEveryPage(int everyPage){ *e [*
return everyPage == 0 ? 10 : everyPage; h^rG5Q
} yL
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v CsE|eMP
privatestaticint getCurrentPage(int currentPage){ U<&=pv
return currentPage == 0 ? 1 : currentPage; \h'7[vkr
} S}rEQGGR{
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privatestaticint getBeginIndex(int everyPage, int =LLpJ+
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currentPage){ mRAt5a#is
return(currentPage - 1) * everyPage; 1p~ORQ
} E8av/O
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privatestaticint getTotalPage(int everyPage, int G.O;[(3ab
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totalRecords){ 6t7FklM%
int totalPage = 0; l4$ sku-
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if(totalRecords % everyPage == 0) %|+aI?
totalPage = totalRecords / everyPage; Dn<3#V
else bK }ZR*)
totalPage = totalRecords / everyPage + 1 ; T\Xf0|y
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return totalPage; (t3gNin
} *PlKl_nP6
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privatestaticboolean hasPrePage(int currentPage){ 6I(Y<LZ5
return currentPage == 1 ? false : true; xKBi".wA
} o% Q7 el$f
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privatestaticboolean hasNextPage(int currentPage, 4P?`<K'
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int totalPage){ }>AA[ba"'
return currentPage == totalPage || totalPage == +cXi|Zf
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0 ? false : true; n}Eu^^d
} =#4>c8MM
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} !oi
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 zk3\v
"
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 ~Fo2M wE2~
:''Swi<H
做法如下: #ZP F&u"
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ?`Mk$Y%my
}vx
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的信息,和一个结果集List: 4`o0?_.'
java代码: 7gOu|t
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/*Created on 2005-6-13*/ si~zg\uY
package com.adt.bo; :{S@KsPqE
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import java.util.List; IDF0nx]
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import org.flyware.util.page.Page; 5cM%PYU4:v
rFt+Y})
/** =Gj~:|;$
* @author Joa DfGq m-c
*/ jC:D>
publicclass Result { w(S&X"~
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private Page page; -f:PgBj
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private List content; m=COF$<
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/** mW[w4J+7P
* The default constructor Ed;!A(64r
*/ yXtQfR
public Result(){ dKXzFyW
super(); 45Zh8 k
} ]RadwH"0!
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/** =D?HL?
* The constructor using fields hWn-[w/l_
* RxPD44jVA
* @param page ,G?Kb#
* @param content D'D IC
*/ is%ef
public Result(Page page, List content){ Ps0<CUyI
this.page = page; j~+(#|
this.content = content; N`X|z
} )VG>6x
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/**
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* @return Returns the content. +#UawYLJ
*/ RMs8aZCa
publicList getContent(){ I+^iOa
return content; U? U3?Y-k`
} *[jq&
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/** J5f}-W@
* @return Returns the page. tk 5p@l
*/ D#Mz#\4o
public Page getPage(){ \SgBI/L^
return page; wYS r.T8Q
} I&^hG\D
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/** BOdlz#&s
* @param content *|6vCR
* The content to set. nI73E
*/ 2>CR]
public void setContent(List content){ NSzTl-eS
this.content = content; 0}:Wh&g
} ka`}lR
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/** 6 pQo_l}
* @param page vMJ_n=Vf
* The page to set. ][ 8`}ki 1
*/ FId,/la
publicvoid setPage(Page page){ ME5M;bz(
this.page = page; xj]^<oi<
} &g8