Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Y[alOJ
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 g h&,U`
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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 Jg%jmI;Y
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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 Qw/H7fvh&
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。 >[gNQJ6
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分页支持类: g
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java代码: z]
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package com.javaeye.common.util; c{K[bppJ*
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import java.util.List; %C(^v)"
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publicclass PaginationSupport { I>z0)pB
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publicfinalstaticint PAGESIZE = 30; 5KDN8pJN
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privateint pageSize = PAGESIZE; kG$U
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privateList items; H~r":A'"*
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privateint totalCount; $23dcC*hI
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privateint[] indexes = newint[0];
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privateint startIndex = 0; Q !G^CG
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public PaginationSupport(List items, int XhG3Of-6
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totalCount){ uu+)r
setPageSize(PAGESIZE); *.F4?i2D
setTotalCount(totalCount); T:(c/>
setItems(items); 'Q F@@ 48
setStartIndex(0); #Vi:-zyY
} `E2HQA@
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public PaginationSupport(List items, int /L? ia
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totalCount, int startIndex){ OtFGo8
setPageSize(PAGESIZE); &i?>mt
setTotalCount(totalCount); ,$<="kJk
setItems(items); wW+@3bPl
setStartIndex(startIndex); Dk`(Wgk2
} r:Rk!z*
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public PaginationSupport(List items, int 8[xl3=
@Lf-=9
totalCount, int pageSize, int startIndex){ Pmj%QhOYE
setPageSize(pageSize); +1=]93gP
setTotalCount(totalCount); -{rUE +
setItems(items); D>efr8Qd@
setStartIndex(startIndex); s'JbG&T[J
} yRv4,{B}X>
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publicList getItems(){ hO] vy>i;
return items; H$={i$*,Y
} M"Q{lR
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publicvoid setItems(List items){ 1'"TO5
this.items = items; _[t:Vme}v
} 7@uhw">mX
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publicint getPageSize(){ *$yU|,
return pageSize; 's_[#a;Vp
} qaZQ1<e
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publicvoid setPageSize(int pageSize){ |g,99YIv>
this.pageSize = pageSize; Js}1_K
} Usz O--.C
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publicint getTotalCount(){ 1E]TH/JK
return totalCount; * faG0le
} <Po$|$_~
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publicvoid setTotalCount(int totalCount){ f )Ef-o
if(totalCount > 0){ KO3X)D<3
this.totalCount = totalCount; urK~]68
int count = totalCount / AMf{E
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pageSize; j9^V)\6)
if(totalCount % pageSize > 0) N83c+vs%c
count++; ;G|#i?JJ
indexes = newint[count]; yeqHeZ
for(int i = 0; i < count; i++){ !
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indexes = pageSize * xka&,`z
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i; ]m<z
} >&%#`PKT
}else{ ^LAnR>mz^r
this.totalCount = 0; &Xh_`*]ox
} :^H2D=z@
} $QB/n63
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publicint[] getIndexes(){ @
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return indexes; &5d~ODO
} It:,8
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publicvoid setIndexes(int[] indexes){ !j%MN{#a
this.indexes = indexes; ^bk:g}o
} Fv$oXg/
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publicint getStartIndex(){ V
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return startIndex; 7 F> a&r
} K;j0cxl
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publicvoid setStartIndex(int startIndex){ GW,RE\Q:
if(totalCount <= 0) <\`qRz0/
this.startIndex = 0; "el}9OitC
elseif(startIndex >= totalCount) F_ -}GN%
this.startIndex = indexes Xb2.t^
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[indexes.length - 1]; Tnoy#w}Ve
elseif(startIndex < 0) 7&&3@96<*#
this.startIndex = 0; %Hu?syo
else{ AjD?_DPc
this.startIndex = indexes ,s`4k?y
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[startIndex / pageSize]; #Oi{7~
} -an~&C5\
}
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publicint getNextIndex(){ 9 iV_
int nextIndex = getStartIndex() + t$z 5m<8
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pageSize; [P*zm 8b
if(nextIndex >= totalCount) crQ_@@X?<
return getStartIndex(); wA\a ]X.
else D6,Ol4d
return nextIndex; J_ 7#UjGA,
} /tj_WO_
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publicint getPreviousIndex(){ 8_/,`}9
int previousIndex = getStartIndex() - @Nn'G{8OG
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pageSize; H5Bh?mw2
if(previousIndex < 0) RA1K$D ?A
return0; RQYD#4|
else o1R:1!"2
return previousIndex; c2Wp 8l
} sB8v:
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} r;_*.|AH
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抽象业务类 mO2u9?N
java代码: _%G;^ b
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/** y({lE3P
* Created on 2005-7-12 pi5DDK
*/ [<WoXS1LX
package com.javaeye.common.business; [ J4n%
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import java.io.Serializable; A|YiSwyy
import java.util.List; RTr"#[
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import org.hibernate.Criteria; o.(Gja4
import org.hibernate.HibernateException; -"rANP-UI
import org.hibernate.Session; 3
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import org.hibernate.criterion.DetachedCriteria; 7%Ou6P$^fr
import org.hibernate.criterion.Projections; ?x/Lb*a^
import Va[t'%~&zR
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org.springframework.orm.hibernate3.HibernateCallback; N}nE?|N=5
import o)n=n!A
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org.springframework.orm.hibernate3.support.HibernateDaoS pS2u&Y"u|
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upport; Pkv+^[(4
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import com.javaeye.common.util.PaginationSupport; Ibg~.>.u{
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public abstract class AbstractManager extends "U/yq
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HibernateDaoSupport { iJ`zWpj+{Q
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privateboolean cacheQueries = false; gC(@]%
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privateString queryCacheRegion; 0BH-kr
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publicvoid setCacheQueries(boolean ]=PkgOJD
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cacheQueries){ C3'?E<F
this.cacheQueries = cacheQueries; izzX$O[=:
} Tgl >
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publicvoid setQueryCacheRegion(String @}2EEo#
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queryCacheRegion){ |{JI=$
this.queryCacheRegion = |w+
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queryCacheRegion; V"B/4v>
} )2Bb,p<Wr
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publicvoid save(finalObject entity){ xIwILY|W=
getHibernateTemplate().save(entity); SLRF\mh!L
} +cM~|
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publicvoid persist(finalObject entity){ = WHI/|&
getHibernateTemplate().save(entity); f[
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} o/ 7[
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publicvoid update(finalObject entity){ IJVzF1vC
getHibernateTemplate().update(entity); [] el4.J,
} [.}Uzx
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publicvoid delete(finalObject entity){ m>RtKCtP
getHibernateTemplate().delete(entity); 10)RLh|+
} {T-^xwc
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publicObject load(finalClass entity, qzEv!?)a
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finalSerializable id){ i[ >U#5
return getHibernateTemplate().load ^C92R"*Qu
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(entity, id); y` {|D*
} bDm7$ (
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publicObject get(finalClass entity, *tv\5KW G
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finalSerializable id){ Ud7Z7?Ym
return getHibernateTemplate().get PT
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(entity, id); !8D>Bczq)
} 7&9w_iCkV
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publicList findAll(finalClass entity){ ?rA3<j
return getHibernateTemplate().find("from Eg8b|!-')8
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" + entity.getName()); Zd88+GS,#
} d3Y;BxEz
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publicList findByNamedQuery(finalString ve:Oe{Ie{
)8oN$20
namedQuery){ d!4TwpIgx
return getHibernateTemplate *l;S"}b*,_
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().findByNamedQuery(namedQuery); ,iY:#E
} ;9~
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publicList findByNamedQuery(finalString query, \<\H1;=.@'
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finalObject parameter){ *X{7m]5
return getHibernateTemplate 9X,iQ
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().findByNamedQuery(query, parameter); ,k=8|=aF
} seRf q&
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publicList findByNamedQuery(finalString query, @56*r@4:q
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finalObject[] parameters){ ~( 0bqt3c
return getHibernateTemplate .6LRg
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().findByNamedQuery(query, parameters); 5gII|8>rQ
} >*opE I+
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publicList find(finalString query){ (wu ciKQ
return getHibernateTemplate().find p*)I QM<B
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(query); w%plK6:6
} Tl'wA^~H
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publicList find(finalString query, finalObject LnKgT1
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parameter){ wu><a!3`=o
return getHibernateTemplate().find H(tC4'tA
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(query, parameter); !icI Rqcf=
} idGn{f((f
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public PaginationSupport findPageByCriteria "(vK.-T
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(final DetachedCriteria detachedCriteria){ UP$>,05z6
return findPageByCriteria L6DYunh}^N
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); lS#:u-k
} &M@c50&%
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public PaginationSupport findPageByCriteria ?|/K(}
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(final DetachedCriteria detachedCriteria, finalint 9<&M~(dwT4
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startIndex){ CLk,]kA'r
return findPageByCriteria \Vroz=IT:
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(detachedCriteria, PaginationSupport.PAGESIZE, !02y'JS1
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startIndex); %OB>FY:|
} 6W{Nw<
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public PaginationSupport findPageByCriteria 8>W52~^fU
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(final DetachedCriteria detachedCriteria, finalint 8h }a:/
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pageSize, {?Y\T
finalint startIndex){ r5ldK?=k+*
return(PaginationSupport) "uT2 DY[
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getHibernateTemplate().execute(new HibernateCallback(){ h@\-]zN{
publicObject doInHibernate {:*G/*1[.
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(Session session)throws HibernateException { ?bt;i>O\
Criteria criteria = YY :{/0?
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detachedCriteria.getExecutableCriteria(session); "igA^^?X1N
int totalCount = R9 Ab.t
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((Integer) criteria.setProjection(Projections.rowCount \8!CKnfs
{U$XHG
()).uniqueResult()).intValue(); R]e&JoY
criteria.setProjection Z37Dv;&ZD
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(null); |;xEKnF
List items = JbL3/h]
&9)/"
criteria.setFirstResult(startIndex).setMaxResults v%AepK&
YTZ :D/
(pageSize).list(); Zi+F IQ(
PaginationSupport ps = Gf3-%s xA
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new PaginationSupport(items, totalCount, pageSize, #::+# G
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startIndex); ,b -
return ps; Anu:
} BYMdX J
}, true); *#b
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} @vyEN.K%mm
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public List findAllByCriteria(final d/j?.\
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DetachedCriteria detachedCriteria){ %(p9AE
return(List) getHibernateTemplate `ovMfL.u
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().execute(new HibernateCallback(){ VgIk '.
publicObject doInHibernate H`fJ<So?
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(Session session)throws HibernateException { PN?;\k)"
Criteria criteria = 9x!kvB6
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detachedCriteria.getExecutableCriteria(session); )1B?<4
return criteria.list(); J&fIWZ
} 4-SU\_
}, true); Pg:xC9w4
} 6'kQ(r>
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public int getCountByCriteria(final e
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DetachedCriteria detachedCriteria){ Nv.
Integer count = (Integer) (wq8[1Wzup
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getHibernateTemplate().execute(new HibernateCallback(){ d]E={}qo&
publicObject doInHibernate xok
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(Session session)throws HibernateException { jY%.t)>)
Criteria criteria = TMY. z
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detachedCriteria.getExecutableCriteria(session); y3b"'-%
return m4oj1h_4
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criteria.setProjection(Projections.rowCount y[85eM
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()).uniqueResult(); =|aZNHqH
} `<d.I%}
}, true); G^nG^HTo5
return count.intValue(); G!sfp}qW
} ,LxZbo!
} 9uWg4U
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用户在web层构造查询条件detachedCriteria,和可选的 "GZ}+K*GG
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 sV2D:%\K:
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PaginationSupport的实例ps。 5PZ7-WJ/
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ps.getItems()得到已分页好的结果集 t !6sU]{
ps.getIndexes()得到分页索引的数组 $Ugc:L<h+
ps.getTotalCount()得到总结果数 #~/9cVm$
ps.getStartIndex()当前分页索引 (0Br`%!F
ps.getNextIndex()下一页索引 )#M$ov
ps.getPreviousIndex()上一页索引 )#i"hnYpQ
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ~<<32t'S:
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 :Bt,.uNC
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一下代码重构了。 1aS:bFi`
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我把原本我的做法也提供出来供大家讨论吧: WgR%mm^
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首先,为了实现分页查询,我封装了一个Page类: >Tl/3{V
java代码: @d~]3T
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/*Created on 2005-4-14*/ GqsV6kH
package org.flyware.util.page; Z7pX%nj_
5EQ)pH+
/** aWRi`poZT
* @author Joa @0PWbs$
* ?'a>?al%>
*/ u(8{5"C
publicclass Page { <)a$5"AP
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/** imply if the page has previous page */ /KC^x=Xv:
privateboolean hasPrePage; BNE:,I*&
kZG;\
/** imply if the page has next page */ C4ktCN
privateboolean hasNextPage; qonStIP
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/** the number of every page */ 6c(b*o
privateint everyPage; *rw6?u9I
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/** the total page number */ qzO Rv
privateint totalPage; PPV T2;9
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/** the number of current page */
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privateint currentPage; x?B`p"ifS
rp<~=X
/** the begin index of the records by the current )K]p^lO
wAW{{ p
query */ 8r"-3<*
privateint beginIndex; @8m%*pBg
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/** The default constructor */ "{E%Y*
public Page(){ ~"\v(\P e
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} Z]{=Jy!F
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/** construct the page by everyPage U&
* @param everyPage ._j?1Fw`
* */ |P&
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public Page(int everyPage){ G#`
this.everyPage = everyPage; <>$CYTb
} gV9bt~
cy?#LS
/** The whole constructor */ =2(52#pT
public Page(boolean hasPrePage, boolean hasNextPage, GY@:[u.&
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int everyPage, int totalPage, ( 1
int currentPage, int beginIndex){ 5c}loOq
this.hasPrePage = hasPrePage; o-&0_Zq_
this.hasNextPage = hasNextPage; YR/I<m`]}
this.everyPage = everyPage; bM?29cs
this.totalPage = totalPage; 2{BS `f
this.currentPage = currentPage; )sK53O$
this.beginIndex = beginIndex; x;:jF_
} &+k*+
/3hY[#e
/** ?-2s}IJO
* @return XefmC6X
* Returns the beginIndex. guf&V}&
*/ ;<T,W[3J
publicint getBeginIndex(){ u.n'dF-
return beginIndex; S?JGg.)
} vN_ 8qzWk
*fj]L?,
/** 60ciI,_`
* @param beginIndex Hq gg*4#
* The beginIndex to set. RS&BS;
*/ - e0[$v
publicvoid setBeginIndex(int beginIndex){ -~(d_
this.beginIndex = beginIndex; 8BZ&-j{
} <2<2[F5Q%
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/** [r Nd7-j <
* @return t~4Cf])
* Returns the currentPage. aY.cx1"
*/ w8$>
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publicint getCurrentPage(){ `bV&n!Y_
return currentPage; .)WEg|D0Ku
} @T L|\T
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/** `jOk6;Z[
* @param currentPage \JR^uJ{Y
* The currentPage to set. 4:**d[|1
*/ kmu`sk"
publicvoid setCurrentPage(int currentPage){ 0!0o[3*
this.currentPage = currentPage; }!Pty25j
} umnQ$y
0
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/** CSW+UaE
* @return Gl|n }wo$
* Returns the everyPage. B6Ajcfy
*/ 0J466H_d{
publicint getEveryPage(){ S#y GqN0i
return everyPage; XHJ`C\xR
} YIgHLM(
\ %MsG
/** [YODyf}M>\
* @param everyPage :O&jm.2m
* The everyPage to set. [iO8R-N8d
*/ eGpKoq7a
publicvoid setEveryPage(int everyPage){ [\h?mlG?
this.everyPage = everyPage; 1$C?+H
} zv/dj04>
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/** UA~ 4O Q]
* @return :Ru8Nm
* Returns the hasNextPage. xqY'-Hom
*/ 3>MILEY^
publicboolean getHasNextPage(){ -z-yk~F
return hasNextPage; Os9EMU$
} C'gv#!Q
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/** uHmvHA~/c8
* @param hasNextPage &!WRa@x0I
* The hasNextPage to set. [dFcxzM-N
*/ $%31Gk[I
publicvoid setHasNextPage(boolean hasNextPage){ b.?;I7r
this.hasNextPage = hasNextPage; {m{nCl)y
} {dRZ2U3
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/** mPQT%%MF
* @return wWf_d jd
* Returns the hasPrePage. j[w=pF,o
*/ ?Y8hy|`
publicboolean getHasPrePage(){
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return hasPrePage; Jn|i!
} .b<W*4{j0H
:wg=H
/** *
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* @param hasPrePage QZ;DZMP
* The hasPrePage to set. #l:
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*/ ErJ@$&7
publicvoid setHasPrePage(boolean hasPrePage){ BV7P_!vt
this.hasPrePage = hasPrePage; X2%(=B
} ohe[rV>EX
W+"^! p|
/** 0MxK+8\y
* @return Returns the totalPage. SVd@-
'-K
* >35w"a7S
*/ OQ
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publicint getTotalPage(){ O_.!qk1R
return totalPage; qAbmQ{|w
} eu_ZsseZ
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/** I"lzOD; eI
* @param totalPage aTeW#:m
* The totalPage to set. @0t[7Nv-1
*/ X?< L<:.
publicvoid setTotalPage(int totalPage){ Qyx~={.C~
this.totalPage = totalPage; @b^$h:H
} 4L{]!dox
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} x@bqPZ t
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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 Pz:,de~5Qm
9Sd?,z
个PageUtil,负责对Page对象进行构造: G![4K#~NM
java代码: ~a`xI
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/*Created on 2005-4-14*/ VzHrKI
package org.flyware.util.page; H6jt[
G?XA",AC
import org.apache.commons.logging.Log; Mb\(52`)Q
import org.apache.commons.logging.LogFactory; ,>kVVpu
GtZ.'?-
/** cYC^;,C &|
* @author Joa } -;)G~h/"
* 4Nt4(3Kf
*/ es#6/
publicclass PageUtil { 7'i{JPm
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privatestaticfinal Log logger = LogFactory.getLog 2;
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(PageUtil.class); >,3 uu}s
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/** {!qnHv\S
* Use the origin page to create a new page Ma$~B0!;s
* @param page l*&N<Yu
* @param totalRecords "qR, V9\
* @return S!z3$@o
*/ J+
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publicstatic Page createPage(Page page, int Q25VG5G
u)o-H!a
totalRecords){ QQV8Vlv"
return createPage(page.getEveryPage(), =MJB:
vBF9!6X .
page.getCurrentPage(), totalRecords); e_KfnPY
} M_ %-A
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/** K#X/j'$^
* the basic page utils not including exception ?(d1;/0v>
u?dPCgs;h
handler U887@-!3
* @param everyPage 'xkl|P>=],
* @param currentPage 7f ub^'_
* @param totalRecords =IQ}Y_xr
* @return page <Ohi+a%6
*/ m=^]93+
publicstatic Page createPage(int everyPage, int <n#X~}i)
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[
currentPage, int totalRecords){ 5~IdWwG*w
everyPage = getEveryPage(everyPage); 8Ala31
currentPage = getCurrentPage(currentPage); @$%GszyQ'
int beginIndex = getBeginIndex(everyPage, y<Xu65
fDqT7}L
currentPage); x:!s+q`
s
int totalPage = getTotalPage(everyPage, 1@KiP`DA
zEW+1-=)+7
totalRecords); F/>\uzu
boolean hasNextPage = hasNextPage(currentPage, |%XTy7^a
~).D\Q\
totalPage); Q35\wQ#
boolean hasPrePage = hasPrePage(currentPage); p2t04p!
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returnnew Page(hasPrePage, hasNextPage, 8^j~uH
everyPage, totalPage, msfE;
currentPage, \2a;z<(
8/dMvAB1So
beginIndex); s[0`
} o&%v"#H2
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privatestaticint getEveryPage(int everyPage){ wv{ Qx^
return everyPage == 0 ? 10 : everyPage; Z*mbhod
}
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privatestaticint getCurrentPage(int currentPage){ ~YCH5,
return currentPage == 0 ? 1 : currentPage; o68i0aFW
} T
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DWKQ>X6
privatestaticint getBeginIndex(int everyPage, int xLoQ0rt
6
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currentPage){ [I4MK%YQ
return(currentPage - 1) * everyPage; ~d]v{<3
} SU~.baP?
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privatestaticint getTotalPage(int everyPage, int QWfSm^
t
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totalRecords){ d8jH?P-"
int totalPage = 0; -9= DDoO
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if(totalRecords % everyPage == 0) f2IH2^)P
totalPage = totalRecords / everyPage; #vV]nI<MF.
else _(h=@cv
totalPage = totalRecords / everyPage + 1 ; A[;deHg=
MYy58N
return totalPage; 4mo/MK&M:
} 0 N>K4ho6{
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privatestaticboolean hasPrePage(int currentPage){ 1;=L]
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return currentPage == 1 ? false : true; %mT/y%&:
} <L qJg
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privatestaticboolean hasNextPage(int currentPage, Dbn344s
#'s$6gT=
int totalPage){ ~KS@Ulrox
return currentPage == totalPage || totalPage == Zhfg
fIQ,}>
0 ? false : true; a&b/C*R_
} NLL"~
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} "E2 0Y"[h
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u)r/#fUZ
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 "V]*ov&[
z fSE7i0
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 mk1R~4v
m1%rm-M
做法如下: Yt(FSb31H
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 E! NtD).=S
hp'oiR;~w
的信息,和一个结果集List: d|NW&PG
java代码: Ie^Ed`
> U?\WgE$
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/*Created on 2005-6-13*/ 6J,h}S
package com.adt.bo; apa&'%7
:Pdh##k
import java.util.List; I8J>>H'#A
+S(# 7
import org.flyware.util.page.Page; 3/n?g7B
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/** Y`ip.Nx
* @author Joa Bzwll
*/ /C!~v!;e
publicclass Result { kb2C9<
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private Page page; ^vd$j-kjTP
LvG$J*
private List content; % E1r{`p
Ly2,*\7
/** Y0,{fw<
* The default constructor PDD2ouv4
*/ `S|F\mI~
public Result(){ $GRw k>N
super(); 9abUh3
} a[~[lk=7
GCN-T1HvA2
/** Vp]7n!g4l
* The constructor using fields +-'F]?DN'
* R|qrK
* @param page [m:cO6DM,
* @param content _1gNU]"
*/ WMtFXkf6"
public Result(Page page, List content){ C:Rs~@tl
this.page = page; I20~bW
this.content = content; 1M??@@X
} G)<B7-72;
c.]QIIdK
/** 0<`qz |_h
* @return Returns the content. G^d3$7
*/ /P,1KVQPh
publicList getContent(){ 7/<~s]D[%
return content; TzaeE
} p+=zl`\=|
k(H]ILL
/** md{nHX&
* @return Returns the page. K@1gK<,a
*/ -rcEG!
public Page getPage(){ _oc6=Z
return page; }~@/r5Zl
} Lf%3-P
n^[a}DX0
/** a%`Yz"<lQ
* @param content }V]b4t
* The content to set. rwj+N%N
*/ H[KX xNYZ_
public void setContent(List content){ NHyUHFY
this.content = content; Jp"29
)w
} Z]b;%:>=
.c]>*/(+
/** )Q`Ycz-
* @param page =a,qRO
* The page to set. x] wi&
*/ `e'wWV
publicvoid setPage(Page page){ FA,n>
this.page = page; o$L%t@
} |E6_TZ#=
} e:
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xwD` R*
ir.RO7f
cL#-vW<s3
2. 编写业务逻辑接口,并实现它(UserManager, *RS/`a;,
Fya*[)HBo
UserManagerImpl) }F{s\qUt
java代码: +&u/R')?6r
vcQl0+&
?QffSSj[s
/*Created on 2005-7-15*/ =A,B'n\R
package com.adt.service; !~C%0{9+u@
o
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import net.sf.hibernate.HibernateException; >+7{PF+sB
>U*p[ FGW
import org.flyware.util.page.Page; ,TWlg
e4=FO;%
import com.adt.bo.Result; P0>2}/;o
.:&`PaMt
/**
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* @author Joa '/qy_7O
*/ :8OT
publicinterface UserManager { L<=Dl
fWJpy#/^*K
public Result listUser(Page page)throws ?u:`?(\
u_NLgM7*
HibernateException; HUjX[w8
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} A"pQOtrm\k
/v9qrZ$$
RdD>&D$I
}kQ{T:q4
j=T8b
java代码: %`k [xz
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A{;"e^a-^l
/*Created on 2005-7-15*/ &C