Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 $,/E"G`
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 H?Sv6W.~
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 ;P ju O
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 WFk%nO/
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。 ]ke9ipj]:
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分页支持类: Bnk<e
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java代码: L?|}!
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package com.javaeye.common.util; O9?.J,,mVh
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import java.util.List; e&T-GL
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publicclass PaginationSupport { P/WGB~NH
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publicfinalstaticint PAGESIZE = 30; 03zt^<
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privateint pageSize = PAGESIZE; !Z\Gv1
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privateList items; J|
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privateint totalCount; wM7Iu86
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privateint[] indexes = newint[0]; iQ2}*:Jc$
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privateint startIndex = 0; J[Mj8ee#
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public PaginationSupport(List items, int {t!
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totalCount){ 4t%Lo2v!X%
setPageSize(PAGESIZE); I;wxgWOP
setTotalCount(totalCount); DQ/rx`BG
setItems(items); u$5.GmKm
setStartIndex(0); 8Ara^Xh}q
} p8-$MF]]6
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public PaginationSupport(List items, int eE
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totalCount, int startIndex){ 1oiSmW\
setPageSize(PAGESIZE); I Ij:3HP
setTotalCount(totalCount); :XAyMK7
setItems(items); ,ZY\})`p
setStartIndex(startIndex); w<h8`K`3
} LfW:G5@-
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public PaginationSupport(List items, int b~ *iL!<
$ `\qY ^.(
totalCount, int pageSize, int startIndex){ ^["D>@yIR
setPageSize(pageSize); s.;'-oA
setTotalCount(totalCount); r|u R!=*|?
setItems(items); K+ M\E[1W
setStartIndex(startIndex); N\. g+ W
} "'Gq4<&y
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publicList getItems(){ \/SOpC
return items; #l-zY}&
} q\jq9)
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publicvoid setItems(List items){ 'CJ_&HR
this.items = items; GoX<d{
} <1lB[:@%U
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publicint getPageSize(){
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return pageSize; >jTiYJI_M
} rc>}3?o
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publicvoid setPageSize(int pageSize){ reYIF*
this.pageSize = pageSize; hMS:t(N{
} !@P{s'<:
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publicint getTotalCount(){ ?G!p4u?C
return totalCount; +T*??OW@
} j p~Tlomp
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publicvoid setTotalCount(int totalCount){ nB :i G
if(totalCount > 0){ {hf_Xro&
this.totalCount = totalCount; p^w)@^f
int count = totalCount / rbv
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pageSize; ir\)Hz2P
if(totalCount % pageSize > 0) /GJL&RMx
count++; r+#g
indexes = newint[count]; ]Y->EME:W
for(int i = 0; i < count; i++){ KdZ=g ZSH
indexes = pageSize * GeB-4img
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i; +G!#
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} !J {[XT
}else{ vg X7B4
this.totalCount = 0; z$g__q-
} y!S:d
} = 4|"<8'
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publicint[] getIndexes(){ 4y5Q5)j
return indexes;
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} b 5K"lPr
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publicvoid setIndexes(int[] indexes){ :~s*yznf
this.indexes = indexes; /']`}*d
} &ns??:\+T
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publicint getStartIndex(){ ih75C"
return startIndex; 5BLBcw\;
} ?l
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publicvoid setStartIndex(int startIndex){ e iH&<AH
if(totalCount <= 0) l`X?C~JhJ
this.startIndex = 0; r~,3
elseif(startIndex >= totalCount) =)iAU/*N
this.startIndex = indexes n
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*N{k#d/
[indexes.length - 1]; u!It';j
elseif(startIndex < 0) {Ngut
this.startIndex = 0; pxyFM@Z](
else{ YReI|{O$c
this.startIndex = indexes ?TW? 2+
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[startIndex / pageSize]; uz3 ?c6b
} , :KJ({wM
} %|R]nB
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publicint getNextIndex(){ r@'~cF]m
int nextIndex = getStartIndex() + KNP^k$=)3c
q/@r#
pageSize; W_/$H_04+
if(nextIndex >= totalCount) hQL@q7tUr
return getStartIndex(); YF;2jl Nm
else 4@ny%_/
return nextIndex; J=O_nup6C
} [V;u7Z\r-
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publicint getPreviousIndex(){ fv*
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int previousIndex = getStartIndex() - hS%oQ)zvE
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pageSize; q!5`9u6
if(previousIndex < 0) @K#}nKN'
return0; 6*|EB|%n
else {Rxb_9
return previousIndex; 7fT_]H8
} 8 r0;054
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} !{g>g%2!
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抽象业务类 )7E7K%:b,
java代码: (CYQ>)a
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/** 3Dj>U*fP
* Created on 2005-7-12 :F"NF
*/ cvtn,Ml6
package com.javaeye.common.business; Z)u_2e
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import java.io.Serializable; x;STt3M~
import java.util.List; !\Xrl) $j{
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import org.hibernate.Criteria; wwa)VgoS[
import org.hibernate.HibernateException; 1dy"
import org.hibernate.Session; l?^}n(_.
import org.hibernate.criterion.DetachedCriteria; LTb#1JC
import org.hibernate.criterion.Projections; iWe'|Br
import ue!4By8T
f/,8sGkX;
org.springframework.orm.hibernate3.HibernateCallback; qyY/:&E, Z
import w(y
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org.springframework.orm.hibernate3.support.HibernateDaoS 9!Fg1h=
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upport; iE
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import com.javaeye.common.util.PaginationSupport; QbWeQ[V{
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public abstract class AbstractManager extends j4#S/:Q<7
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HibernateDaoSupport { "1Y DT-I"
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privateboolean cacheQueries = false; W{]r_`=:6S
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privateString queryCacheRegion; )@.0ai
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publicvoid setCacheQueries(boolean !]z4'* )W
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cacheQueries){ [bBPs&7u
this.cacheQueries = cacheQueries; ?,eq86-M
} (S&D
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publicvoid setQueryCacheRegion(String ORIXcj]
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queryCacheRegion){ &?9~e>.OS
this.queryCacheRegion = {^R"V ,)
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queryCacheRegion; PiNf;b^9
} =cx_3gCr{
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publicvoid save(finalObject entity){ TSRl@QVy
getHibernateTemplate().save(entity);
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} CL!s #w1I\
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publicvoid persist(finalObject entity){ S\2@~*{-8
getHibernateTemplate().save(entity); z&.F YGq}
} XpT~]q}
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publicvoid update(finalObject entity){ ]L\]Ll;
getHibernateTemplate().update(entity); #BI Z|
} ^8g<>,$
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publicvoid delete(finalObject entity){ iis}=i7|
getHibernateTemplate().delete(entity); 94[8~_{fG
} OI^qX;#Kd
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publicObject load(finalClass entity, <EuS6Pg
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finalSerializable id){ ]_! .xx>
return getHibernateTemplate().load hx}X=7w
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(entity, id); Tnnj8I1v
} ,Q+.kAh !G
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publicObject get(finalClass entity, 2)|G%f_lS
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finalSerializable id){ *UdP1?Y
return getHibernateTemplate().get gt(!I^LHYc
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(entity, id); .fNLhyd
} Ot~buf'|
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publicList findAll(finalClass entity){ TA"gU8YQ
return getHibernateTemplate().find("from x\Kt}/9 7e
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" + entity.getName()); "Q1oSpF
} W`jKe-jF
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publicList findByNamedQuery(finalString =n_>7@9l
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namedQuery){ z3|5E#m
return getHibernateTemplate `t]8 [P5
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().findByNamedQuery(namedQuery); %07vH&<C.
} E
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publicList findByNamedQuery(finalString query, Q\*zF,ek
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finalObject parameter){ Q.l3F3;
return getHibernateTemplate <s (o?U
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().findByNamedQuery(query, parameter); A 1aN<!ehB
} rCdTn+O2
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publicList findByNamedQuery(finalString query, G~zP&9N|
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finalObject[] parameters){ Vx=tP.BO]
return getHibernateTemplate qfgw^2aUa
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().findByNamedQuery(query, parameters); 7vB6IF
} vF'Y; M
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publicList find(finalString query){ Ak@y"!wnM
return getHibernateTemplate().find i$XT Qr0K=
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(query); 2;ac&j1
} $8NM[R.8^4
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publicList find(finalString query, finalObject #} `pj}tQ
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parameter){ Lz`_&&6
return getHibernateTemplate().find "V<7X%LIX
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(query, parameter); {[r}gS%
} ZE6W"pbjU
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public PaginationSupport findPageByCriteria O7zj8
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(final DetachedCriteria detachedCriteria){ }_9yemP
return findPageByCriteria vH>s2\V"
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); p 8lm1;
} `&FfGftc
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public PaginationSupport findPageByCriteria Q^Q6|
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(final DetachedCriteria detachedCriteria, finalint H:,Hr_;nC
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startIndex){ 7y=1\KW(
return findPageByCriteria CjmF2[|
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(detachedCriteria, PaginationSupport.PAGESIZE, uB+:sX-L
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startIndex); ]?0]K!7Ea
} n<DZb`/uHZ
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public PaginationSupport findPageByCriteria !'kr:r}gg
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(final DetachedCriteria detachedCriteria, finalint u'Z^|IVfo
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pageSize, {6HgKI
finalint startIndex){ 7J5Yzu)D
return(PaginationSupport) } v3w-
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getHibernateTemplate().execute(new HibernateCallback(){ w)"F=33}5
publicObject doInHibernate 9mB] \{^
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(Session session)throws HibernateException { T&]IPOH9
Criteria criteria = 9PJnKzQ4
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detachedCriteria.getExecutableCriteria(session); Rh{`#dI~=
int totalCount = w,;ox2
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((Integer) criteria.setProjection(Projections.rowCount ]1|OQYG
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()).uniqueResult()).intValue(); 9Q&]5|x
criteria.setProjection 6'jgjWEe3&
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(null); M8f[ ck
List items = \};
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criteria.setFirstResult(startIndex).setMaxResults !s[gv1
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(pageSize).list(); 9oj0X>| 1
PaginationSupport ps = nSq$,tk(
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new PaginationSupport(items, totalCount, pageSize, !r9~K^EI
*!`bC@E
startIndex); y+$a}=cb0
return ps; Ba9"IXKH
} +D M,+{}
}, true); %=i/MFGX
} P&AaD!Qn
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public List findAllByCriteria(final <E7y:%L[Go
){4$oXQ
DetachedCriteria detachedCriteria){ jN!sLW
return(List) getHibernateTemplate ``Rg0o
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().execute(new HibernateCallback(){ hGo/Ve+@
publicObject doInHibernate FES0lw{G#
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(Session session)throws HibernateException { o>yo9n%t
Criteria criteria = xm> y3WC
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detachedCriteria.getExecutableCriteria(session); MG3xX;
return criteria.list(); -
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} VaTA|=[;
}, true); A2I\T,Z
} +jj] tJ$[
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public int getCountByCriteria(final A 1x
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DetachedCriteria detachedCriteria){ J|e3
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Integer count = (Integer) XknbcA|
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getHibernateTemplate().execute(new HibernateCallback(){ 1N +ju"2R
publicObject doInHibernate 9oVprd>%@
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(Session session)throws HibernateException { 6V-JyTcxGI
Criteria criteria = j +Ro?
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detachedCriteria.getExecutableCriteria(session); UZu.B!4
return u\=yY.
&&te(DC\
criteria.setProjection(Projections.rowCount \|$GB U
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()).uniqueResult(); (_eM:H=e>
} ^1X
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}, true); gA&`vnNP
return count.intValue(); (o1o);AO
} D^A#C<Gs
} C40W@*6S2
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用户在web层构造查询条件detachedCriteria,和可选的 cfPQcB>A
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ]u"x=S93
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PaginationSupport的实例ps。 g3\13<
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ps.getItems()得到已分页好的结果集 )h/Qxf
ps.getIndexes()得到分页索引的数组 LO)p2[5#R
ps.getTotalCount()得到总结果数 DC*6=m_
ps.getStartIndex()当前分页索引 Lg+cHaA
ps.getNextIndex()下一页索引 >!#or- C
ps.getPreviousIndex()上一页索引 Fj1'z5$
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 &u~%5;
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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 n;~6'fxe
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一下代码重构了。 Z+Ppd=||,
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我把原本我的做法也提供出来供大家讨论吧: A7TV-eWG
sKDL=c;?j
首先,为了实现分页查询,我封装了一个Page类: JO\KTWtjO
java代码: 5} 1qo7;
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/*Created on 2005-4-14*/ ;ZR^9%+y9
package org.flyware.util.page; |}<!O@<|
n)R[T.E)+
/** HkyN$1s
* @author Joa ;f2<vp;U
* CV*
*/ 2yndna-
publicclass Page { $ZnVs@:S
G/V0Yn""
/** imply if the page has previous page */ | @p
privateboolean hasPrePage; pe-%`1iC0>
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/** imply if the page has next page */ RzqU`<//
privateboolean hasNextPage; 6('xIE(R
x!A5j
$k0
/** the number of every page */ ;`FR1KIg
privateint everyPage; n$3w=9EX*
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/** the total page number */ B[[1=
privateint totalPage; !tuK.?q|l
vXibg
/** the number of current page */ wKAxUPzm
privateint currentPage; s7:w>,v/
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/** the begin index of the records by the current xO;Qr.3PX
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query */ Rlx
privateint beginIndex; KL8WT6!RZ
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/** The default constructor */ @D@'S:3
public Page(){ =B
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} :c0 |w
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/** construct the page by everyPage :w:ql/?X
* @param everyPage aN~x3G
* */ anFl:=
public Page(int everyPage){ ;Yn_*M/*
this.everyPage = everyPage; 8YkCTJfBGu
} *AA78G|
fDZnC Fa
/** The whole constructor */ fh@/fd
public Page(boolean hasPrePage, boolean hasNextPage, u&$1XZ!es
B \>W
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int everyPage, int totalPage, `-<m#HF:)d
int currentPage, int beginIndex){ 8:}$L)[V
this.hasPrePage = hasPrePage;
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this.hasNextPage = hasNextPage; "
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this.everyPage = everyPage; S{qn^\0
this.totalPage = totalPage; "gq_^&
this.currentPage = currentPage; L&qY709
this.beginIndex = beginIndex; _<l 9j;6
} @wW)#!Mou
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/** }3y Q*<
* @return Ui;PmwQc&
* Returns the beginIndex. ,\E5et4
*/ UJGmaE
publicint getBeginIndex(){ a8r+G]Z
return beginIndex; StM)lVeF
}
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/** 0/?=FM>
* @param beginIndex k{pn~)xg
* The beginIndex to set. nokMS
*/ %{^kmlO
publicvoid setBeginIndex(int beginIndex){ d15E$?ZLH
this.beginIndex = beginIndex; BG2Z'WOH
} @!s(Zkpev
BZ@v8y _TA
/** Wx-rW
* @return ,ikn%l#cm
* Returns the currentPage. /BfCh(B
*/ 7\JA8mm
publicint getCurrentPage(){ s&Qil07Vl
return currentPage; !8Q9RnGn
} (1?k_!)T
CiC@Z,ud`
/** ,v*<yz/
* @param currentPage ED
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* The currentPage to set. d)jX%Z$LC
*/ o$bD?Zn
publicvoid setCurrentPage(int currentPage){ xm}`6B^f
this.currentPage = currentPage; QzA/HP a
} 8rgNG7d
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/** b. oA}XP
* @return 9A1w5|X
* Returns the everyPage. O,!4
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*/ 6'vt
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publicint getEveryPage(){ ?kM53zbT#
return everyPage; `PvGfmYOl
} T1pMe{
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/** O8S"B6?$~'
* @param everyPage j8#B
* The everyPage to set. >l|dLyiae
*/ YfOO]{x,X
publicvoid setEveryPage(int everyPage){ O{`r.H1',
this.everyPage = everyPage; CF+:9PG
} .=-K7.X.)
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/** L~xzfO
* @return bLi>jE.%.
* Returns the hasNextPage. p3(&9~s
*/ (_O_zu8_
publicboolean getHasNextPage(){ 9:jZ3U
return hasNextPage; cE0Kvqe`
} Ok2>%e
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/** wXxk+DV@
* @param hasNextPage ~",,&>#[K
* The hasNextPage to set. aj*%$!SU+
*/ zMQ|j_l9E
publicvoid setHasNextPage(boolean hasNextPage){ Qr
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this.hasNextPage = hasNextPage; _w>9Z>PR
} cYMlcwS
:N([s(}!$2
/** obhq2sK
* @return 0q
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* Returns the hasPrePage. ,l_n:H+"F
*/ zSFqy'b.M-
publicboolean getHasPrePage(){ ="*8ja-K
return hasPrePage; 3xnu SOdh
} y-c2tF@'v
sS|N.2*
/** \aG:l.IM0
* @param hasPrePage *T'>-nm]
* The hasPrePage to set. L'Fy\K\
*/ 0jN?5j
publicvoid setHasPrePage(boolean hasPrePage){ Kq0!.455
this.hasPrePage = hasPrePage; c0%%X!!$
} W!BIz&SY:-
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/** 9
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* @return Returns the totalPage. yy6?16@
*
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*/ vc_ 5!K%[
publicint getTotalPage(){ 2!35Tj"RFE
return totalPage; $xf{m9 8
} cSSrMYX2
Z{ A)
/** *OQr:e<}
* @param totalPage G:2m)0bW
* The totalPage to set. ;9hi2_luV
*/ -v(.]`Wo&;
publicvoid setTotalPage(int totalPage){ z@0*QZ.y1
this.totalPage = totalPage; {~"6/L
} +L86w7
058+_xX
} Ibd
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iZ3%'~K<3J
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 zU'\r~c
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个PageUtil,负责对Page对象进行构造: .hxcx>%
java代码: |E)Es!dr
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/*Created on 2005-4-14*/ dik+BBu5z
package org.flyware.util.page; N@>,gm@UU
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import org.apache.commons.logging.Log; ^vjN$JB
import org.apache.commons.logging.LogFactory; R;_U BQ)
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/** YEWHr>&Z
* @author Joa w-%H\+J
* :_q
*/ <z*SO
a
publicclass PageUtil { DVNGV
#Pulbk8
privatestaticfinal Log logger = LogFactory.getLog @]#0jiS
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(PageUtil.class); @JWoF^U
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/** [*j
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* Use the origin page to create a new page 6N&S3<c4JO
* @param page $GyO+xF
* @param totalRecords "bRg_]\q6
* @return >Udb*76
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*/ onM ~*E
publicstatic Page createPage(Page page, int Ne<"o]_M
DG x9 \8^
totalRecords){ kN4nRW9z
return createPage(page.getEveryPage(), n7"e 79
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page.getCurrentPage(), totalRecords); av( d0E}}b
} D@yg)$;z
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/** XB)e;R
* the basic page utils not including exception gOI#$-L
*=1;HN3
handler &t+
* @param everyPage \guZc}V]:\
* @param currentPage .[hQ#3)W
* @param totalRecords %:n1S]Vr
* @return page 6rEt!v #K[
*/ {6v|d{V+e
publicstatic Page createPage(int everyPage, int /vl]Oa&U
!<!sB)
currentPage, int totalRecords){ kSH3)CC P
everyPage = getEveryPage(everyPage); b'^OW
currentPage = getCurrentPage(currentPage); 2sjP":
int beginIndex = getBeginIndex(everyPage, ,P ?TYk
-L4AM%(9
currentPage); N7%+n*Z
int totalPage = getTotalPage(everyPage, 5r<%xanXW/
:".:Wd
totalRecords); 2,O-/A;tW*
boolean hasNextPage = hasNextPage(currentPage, Wiqy".YY
dhN[\Z%
totalPage); }(AUe5aw`G
boolean hasPrePage = hasPrePage(currentPage); >w jWX{&?
aTs5^Kh')
returnnew Page(hasPrePage, hasNextPage, aC>r5b#:
everyPage, totalPage, TR rO-
currentPage, .9Bimhc6K
e0HG"z4
beginIndex); PKR0y%Ar
} "_ b
Sy
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privatestaticint getEveryPage(int everyPage){ >\K<q>*
return everyPage == 0 ? 10 : everyPage; /d5_-AB(v
} !Y-MUZ$f
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privatestaticint getCurrentPage(int currentPage){ ^ 3LM%B
return currentPage == 0 ? 1 : currentPage; $=$I^hV
} PG9won5_
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privatestaticint getBeginIndex(int everyPage, int PGMu6$
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currentPage){ D5)qmu
return(currentPage - 1) * everyPage; 6g!#"=ls;
} R:B-4
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privatestaticint getTotalPage(int everyPage, int 8Uvf9,I'
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totalRecords){ k+44ud.j
int totalPage = 0; sMli! u
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if(totalRecords % everyPage == 0) .9> er
totalPage = totalRecords / everyPage; YL&$cT]1
else it\{#rb=4
totalPage = totalRecords / everyPage + 1 ; a=k+:=%y
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return totalPage; a=gTGG"9
} z-uJ+SA
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privatestaticboolean hasPrePage(int currentPage){ B4R!V!Z*
return currentPage == 1 ? false : true; <\?ySto
} -:m;ePK
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privatestaticboolean hasNextPage(int currentPage, [9a0J):w{
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int totalPage){ oo3ZYA
return currentPage == totalPage || totalPage == x2/|i?ZO
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0 ? false : true; TclZdk]%T
} g8mVjM\B;
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} e}f!zA
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 \,[Qg#W$u
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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 1[J&^@t[h6
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做法如下: kJ>l,AD/
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 X6!u(plVQ
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的信息,和一个结果集List: ;%]Q%7
java代码: \Yz>=rY
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/*Created on 2005-6-13*/ Lh"Je-x<<
package com.adt.bo; @= 6}w_
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import java.util.List; c>!>D7:7
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import org.flyware.util.page.Page; &B#HgWud
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/** w@X<</`
* @author Joa ]XJpy-U
*/ rcq(p(!
publicclass Result { tn6\0_5n
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private Page page; DuZ51[3_L
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private List content; `9s5 *;Z
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/** fa/
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* The default constructor J@H9nw+Q
*/ D._q'v<
public Result(){ 8G1Tpn
super(); K`j#'`/KC
} Yj/S(4(h?
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/** KZ`d3ad
* The constructor using fields {_ww1'|A
* EHcqj;@m
* @param page X;v/$=-mz
* @param content =:1f
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*/ "xa<Q%hk
public Result(Page page, List content){ j?+FS`a!
this.page = page; 4bhm1Q
this.content = content; *r?g&Vw$m
} 4NQS'*%D
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/** b3H~a2"d
* @return Returns the content. t=~al8
*/ JQ%e'
publicList getContent(){ V(=~p[
return content; N/8qd_:8
} 2
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/** 5sM-E>8G^{
* @return Returns the page. W.-[ceM
*/ yps7MM-r
public Page getPage(){ [O&2!x
return page; pxM^|?Hxc
} +yVz)
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/** VDx=Tsu-
* @param content nDkyo>t.
* The content to set. %QVX1\>]
*/ -G(z!ed
public void setContent(List content){ +su>0'a
this.content = content; giyKEnP
} ul?'kuYk
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/** sn+i[
* @param page H-nk\ K<|
* The page to set. <)uUAh
*/ j7xoe9;TxI
publicvoid setPage(Page page){ ch 4z{7
this.page = page; {Lk~O)E
} ,6}HAC $
} >+7+ gSD#:
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2. 编写业务逻辑接口,并实现它(UserManager, 62PtR`b>
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UserManagerImpl) eq<xO28z
java代码: "k)( ,
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