Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 tM;cvc`/
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 m~*qS4
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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 $kxP5q%9
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 x?V^l*
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分页支持类: 0RtZTCGO
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java代码: g*My1+J!
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package com.javaeye.common.util; ']eN4H&=?}
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import java.util.List; jvsSP?]n
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publicclass PaginationSupport { 3))CD,|
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publicfinalstaticint PAGESIZE = 30; ~EY)c~H
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privateint pageSize = PAGESIZE; T@.+bD
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privateList items; 8tR6.09'
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privateint totalCount; o.NU"$\?
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privateint[] indexes = newint[0]; <Tjhj*
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privateint startIndex = 0; eA2*}"W
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public PaginationSupport(List items, int zeQ~'ao<
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totalCount){ 9C,gJp}P
setPageSize(PAGESIZE); {$[0YRNk
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setTotalCount(totalCount); 4y+hr
setItems(items); (*\&xRY|C
setStartIndex(0); Lf^
7|
} r+[g.`
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public PaginationSupport(List items, int D9NRM;v
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totalCount, int startIndex){ > `eo 0
setPageSize(PAGESIZE); rU"AO}6\@
setTotalCount(totalCount); u c!6?+0h
setItems(items); 4`#%<G
setStartIndex(startIndex); ,Aq, f$5V
} B^dMYFelJ
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public PaginationSupport(List items, int ?^!J:D?
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totalCount, int pageSize, int startIndex){ E{JTy{z-
setPageSize(pageSize); Th%w-19,8
setTotalCount(totalCount); 7YTO{E6]d\
setItems(items); n~`jUML2d
setStartIndex(startIndex); >^9j>< Z
} 7eM6 B#rI
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publicList getItems(){ !$iwU3~<
return items; md{1Jn"
} ?P7QAolrr
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publicvoid setItems(List items){ SP2";,%/9
this.items = items; u{WI 4n?
} e
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publicint getPageSize(){ l3MA&&++KF
return pageSize; E?K(MT&@
} mrE>o!
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publicvoid setPageSize(int pageSize){ <4?(|Vh[m]
this.pageSize = pageSize; ;2BPEo>z9
} YL;*%XmAG
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publicint getTotalCount(){ q,Nqv[va
return totalCount; !C' Y
7
} f]Z9=
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publicvoid setTotalCount(int totalCount){ K)`l >o1
if(totalCount > 0){ `a7b,d
this.totalCount = totalCount; W7V#G(cpU
int count = totalCount / QE;,mC>
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pageSize; ~ebm,3?
if(totalCount % pageSize > 0) J(,gLl
count++; S^e e<%-
indexes = newint[count]; z*^vdi0
for(int i = 0; i < count; i++){ Z79Y$d>G<E
indexes = pageSize * Q?m= a0g
pi*?fUg!W
i; Z
+}#
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} ~|wh/]{b9
}else{ ]mO7O+
this.totalCount = 0; P'5Q}7
} :bp8S@
} l=&Va+K
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publicint[] getIndexes(){ 60p*4>^v
return indexes; pEGHW;
} 7tT L,Nxe
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publicvoid setIndexes(int[] indexes){ 6CWm;%B#G
this.indexes = indexes; ;&RHc#1F
} :?gk=JH:
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publicint getStartIndex(){
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return startIndex; u@[JX1&3"n
} 0_map z
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publicvoid setStartIndex(int startIndex){ QW@`4W0F
if(totalCount <= 0) 3)py|W%X$
this.startIndex = 0; ATU] KL!{
elseif(startIndex >= totalCount) <Dp[F|r
this.startIndex = indexes v/7iu*u
o{
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[indexes.length - 1]; ApAHa]Ccp
elseif(startIndex < 0) F1zsGlObu}
this.startIndex = 0; O>L
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else{ Y)v_O_`
this.startIndex = indexes 1|\/2
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[startIndex / pageSize]; .3T#:Hl
} m3K .\3
} _NJq%-,'
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publicint getNextIndex(){ 7j L.\O
int nextIndex = getStartIndex() + ?wS/KEl=O
HOAgRhzE
pageSize; , 8F(R%v
if(nextIndex >= totalCount) 41`&/9:"_M
return getStartIndex(); q--;5"=S
else js\|xfDxP
return nextIndex; t1tZ:4
} 4 '6HX#J
R k).D6
publicint getPreviousIndex(){ RBzBR)@5
int previousIndex = getStartIndex() - [8Zvs=1
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pageSize; eE-@dU?
if(previousIndex < 0) {m+(j (6-
return0; =m?x|Zc_v
else :Vf :_;
return previousIndex; %7~~*_G
} ]RJcY1
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} x:)8+Rn}
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抽象业务类 nZ 0rxx[V?
java代码: 8E|
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/** 5L}qL?S`x|
* Created on 2005-7-12 _# /zH~V%
*/ hkq[xgX
package com.javaeye.common.business; P+~{q.|._c
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import java.io.Serializable; }G#TYF}
import java.util.List; _8CE|<Cn
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import org.hibernate.Criteria; ?p8(Uc#73
import org.hibernate.HibernateException; ,5_Hen=PI
import org.hibernate.Session; #;32(II
import org.hibernate.criterion.DetachedCriteria; *L3>:],7
import org.hibernate.criterion.Projections; zMkjdjb
import -&u2C}4s
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org.springframework.orm.hibernate3.HibernateCallback; <"g ^V
import m|)Mc VV
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org.springframework.orm.hibernate3.support.HibernateDaoS 4_E{
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upport; 9oK#n'hjb
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import com.javaeye.common.util.PaginationSupport; |[tlR`A $
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public abstract class AbstractManager extends y^#jM
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HibernateDaoSupport { 5{Xld,zw
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privateboolean cacheQueries = false; ~@x@uY$5
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privateString queryCacheRegion; )pS1yYLj
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publicvoid setCacheQueries(boolean Qo!/]\
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cacheQueries){ 5JE8/CbH
this.cacheQueries = cacheQueries; >g]S"ku|
} _y q"F#,*
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publicvoid setQueryCacheRegion(String 5TqT`XTzm
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queryCacheRegion){ <n iq*
this.queryCacheRegion = %t&5o>1C
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queryCacheRegion; jlV~-}QKb7
} !\Y85o>JU
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publicvoid save(finalObject entity){ 85rXm*Df
getHibernateTemplate().save(entity); PK#; \Zw
} NGD?.^ (G
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publicvoid persist(finalObject entity){ 1us-ootsjP
getHibernateTemplate().save(entity); G 2]/g
} 3%?01$k
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publicvoid update(finalObject entity){ NJfI9 L
getHibernateTemplate().update(entity); q<L>r?T[
} nYJ)M
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publicvoid delete(finalObject entity){ o+sb2:x
getHibernateTemplate().delete(entity); 'u }|~u?m
} <StyO[
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publicObject load(finalClass entity, -4|\,=j
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finalSerializable id){ P9~7GFas|
return getHibernateTemplate().load 0FrmZ$
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(entity, id); pqmS
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} '!*,JG5_
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publicObject get(finalClass entity, vA rM.Bu>b
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finalSerializable id){ rPVz!(;k
return getHibernateTemplate().get 6-U+<[,x
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(entity, id); 8W$uw~|dw
} uGIA4CUm
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publicList findAll(finalClass entity){ {&,9Zy]"S
return getHibernateTemplate().find("from QiB^U^f
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" + entity.getName()); iaAVGgA9+
} %~`8F\Hiu
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publicList findByNamedQuery(finalString 2GNtO!B.
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namedQuery){
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return getHibernateTemplate Ws"eF0,'Z
7`;55Se
().findByNamedQuery(namedQuery); Jh2eo+/%
} *-~B{2b<
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publicList findByNamedQuery(finalString query, a+!#cQl
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finalObject parameter){ !=j\pu}
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return getHibernateTemplate DC4,*a~
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().findByNamedQuery(query, parameter); .#zmX\a
} OQ&?^S`8',
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publicList findByNamedQuery(finalString query, //63?s+
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finalObject[] parameters){ c e`3&
return getHibernateTemplate `6:;*#jO,
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().findByNamedQuery(query, parameters); ]m}<0-0
} 44T>Yp09
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publicList find(finalString query){ .a._WZF
return getHibernateTemplate().find E-,/@4k
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(query); bp G`,[
} xE(VyyR
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publicList find(finalString query, finalObject pE{ZWW[@+
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parameter){ ]O
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return getHibernateTemplate().find =Q985)Y&
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(query, parameter); n(^{s5 Rr
} )-$Od2u2c
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public PaginationSupport findPageByCriteria GtcY){7
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(final DetachedCriteria detachedCriteria){ @QiuCB
return findPageByCriteria 1U[8OM{$
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); ud]O'@G<
} dL%?k@R
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public PaginationSupport findPageByCriteria UFnz3vc
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(final DetachedCriteria detachedCriteria, finalint 7PG&G5
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startIndex){ w?^qAj(*d
return findPageByCriteria *FoH'\=
*Dx&} "
(detachedCriteria, PaginationSupport.PAGESIZE, JWhi*je
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startIndex); wc7gOrPpm
} M0[7>N_
* SH5p
public PaginationSupport findPageByCriteria <GoUth.#
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(final DetachedCriteria detachedCriteria, finalint )cnH %6X
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pageSize, (V2~txMh
finalint startIndex){ !{'C.sb?~
return(PaginationSupport) E.V#Bk=
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getHibernateTemplate().execute(new HibernateCallback(){ m\QUt ;
publicObject doInHibernate )}QtK+Rq
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(Session session)throws HibernateException { YlfzHeN1
Criteria criteria = X|!VtO
}7p`8?
detachedCriteria.getExecutableCriteria(session); eUP.:(E
int totalCount = d:08@~#
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((Integer) criteria.setProjection(Projections.rowCount \;&WF1d`ac
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()).uniqueResult()).intValue(); u#9 H
criteria.setProjection AE`z~L,
5>z`==N)
(null); e}%~S9\UL5
List items = >bQ'*!
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criteria.setFirstResult(startIndex).setMaxResults /)6+I(H
IM-O<T6r[N
(pageSize).list(); NP
}b
PaginationSupport ps = X2CpA;#;7l
~z;G$jd
new PaginationSupport(items, totalCount, pageSize, U^aMh-
}N@8zB~X
startIndex); -U&k%X
return ps; a=m4)tjk
} )4h4ql W
}, true); Er@'X0n
} [ PXv8K%]p
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public List findAllByCriteria(final PfF5@W;E;
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DetachedCriteria detachedCriteria){ -^C^3pms
return(List) getHibernateTemplate .W;,~.l
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().execute(new HibernateCallback(){ KK-}&N8
publicObject doInHibernate IR_&dWHyc
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(Session session)throws HibernateException { PBkTI2 v
Criteria criteria = `i~kW
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detachedCriteria.getExecutableCriteria(session); =Oyn<
return criteria.list(); 2~ [
} Q)mYy
}, true); Hl"^E*9x
} nF"NXYa
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public int getCountByCriteria(final $p(
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DetachedCriteria detachedCriteria){ g
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Integer count = (Integer)
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getHibernateTemplate().execute(new HibernateCallback(){ xLN$!9t
publicObject doInHibernate dbe\ YE
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(Session session)throws HibernateException { rq(9w*MW:
Criteria criteria = Zb&5)&'X
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detachedCriteria.getExecutableCriteria(session); c^F@9{I
return m#Y[EPF=|
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criteria.setProjection(Projections.rowCount bJ!(co6t
(fqU73
()).uniqueResult(); qh~$AJ9sB
} 9EFQo^
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}, true); *8% nbR
return count.intValue(); NG+%H1!$_
} prw% )#,
} #Fkn-/nL
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用户在web层构造查询条件detachedCriteria,和可选的 "2_nN]%u-
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 p!/ *(TT
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PaginationSupport的实例ps。 jJ7 "9
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ps.getItems()得到已分页好的结果集 os[i
ps.getIndexes()得到分页索引的数组 `st^i$A
ps.getTotalCount()得到总结果数 :G4)edwe
ps.getStartIndex()当前分页索引 WR zIK09@
ps.getNextIndex()下一页索引 0f;`Zj0l8
ps.getPreviousIndex()上一页索引 ' JAcN@q~z
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 g{e@I;F
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 7J|eL
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一下代码重构了。 l0BYv&tu
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我把原本我的做法也提供出来供大家讨论吧: '/GZ/$a_l
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首先,为了实现分页查询,我封装了一个Page类: =SK{|fBB
java代码: +GlG.6
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/*Created on 2005-4-14*/ PS/00F/Ak
package org.flyware.util.page; t@+z r3
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/** ;|D8"D6]
* @author Joa yL"pzD`[H
* ZJ'FZ8Sx
*/ /rzZU} 3[
publicclass Page { ^2eH0O!
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/** imply if the page has previous page */ E-b3#\^:
privateboolean hasPrePage; T?EFY}f
#TD0)C/
/** imply if the page has next page */ oF=UjA
privateboolean hasNextPage; o]WG8Mo-
T`K4n U#
/** the number of every page */ JAS!eF
privateint everyPage; t4FaU7
89l{h8R
/** the total page number */ *K=Yrisz
privateint totalPage; >-4kO7.V
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/** the number of current page */ $|H7fn(r
privateint currentPage; )" H r3
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/** the begin index of the records by the current vF.Ml
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query */ hgI;^ia
privateint beginIndex; hG
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/** The default constructor */ ALl0(<u67
public Page(){ @1tv/W
vw/X
} &&sCaNb
>
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/** construct the page by everyPage #NR9\
* @param everyPage Q??nw^8Hi
* */ pb=yQ}.
public Page(int everyPage){ ~JSa]6:_+
this.everyPage = everyPage; W6L}T,epX
} ^laf!kIP
d ~3GEK
/** The whole constructor */ hwB>@r2
public Page(boolean hasPrePage, boolean hasNextPage, DgRA\[c
V;>u()
)Qixde>]p
int everyPage, int totalPage, wwh)B92Y5
int currentPage, int beginIndex){ A Z& ]@Ao
this.hasPrePage = hasPrePage; N
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this.hasNextPage = hasNextPage; O*y@4AR"S
this.everyPage = everyPage; z\r|5Z
this.totalPage = totalPage; 6/&aBE=
this.currentPage = currentPage; c&u~M=EW
this.beginIndex = beginIndex; m9m]q&hx
} kK il]L
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/** P},d`4Ty@
* @return d@0&
* Returns the beginIndex. 'k9dN
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*/ (v$$`zh
publicint getBeginIndex(){ {ehAF=C
return beginIndex; #E#.`/4
} Y~ ( <H e?
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/** yHt
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* @param beginIndex 990sE
t?
* The beginIndex to set. zMW[Xx!
*/ ^lCQHz
publicvoid setBeginIndex(int beginIndex){ )Y:9sd8g7
this.beginIndex = beginIndex; T{Rhn V1
} b+3QqbJ[F
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/** XI*cu\7sy
* @return qH-':|h7
* Returns the currentPage. #pm0T1+jW
*/ h.D*Y3=<
publicint getCurrentPage(){ Lavm
return currentPage; 5\|u]
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} e-.s63hm
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/** @5y ~A}Vd
* @param currentPage c _faW
* The currentPage to set. 9X6l`bo'
*/ P-c<[DSM'I
publicvoid setCurrentPage(int currentPage){ gkN
)`/`*
this.currentPage = currentPage; XK7$Xbd
} [J71aH
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/** K)d]3V!
* @return $7bl,~Z
* Returns the everyPage. I||4.YT
*/ lImg+r T{
publicint getEveryPage(){ 5Sm)+FC:
return everyPage; E0Neo _7
} y Ddi+
bn8`$FA^
/** KL}o%wfLy
* @param everyPage }co*%F{1
* The everyPage to set. PfKF!/c
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*/ <#r/4a"V
publicvoid setEveryPage(int everyPage){ B}YpIb]d
this.everyPage = everyPage; t/4&=]n\u
} ' QrvkQ
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/** (,5,}
* @return !u;r<:g!
* Returns the hasNextPage. :J{| /"==
*/ w6 x{<d
publicboolean getHasNextPage(){ rL=_z^.P
return hasNextPage; ">pt,QV
} @Pt,N
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/** 7kZ-`V|\.
* @param hasNextPage 8'Y7lOXS
* The hasNextPage to set. AKbrXKx
*/ }>|M6.n "
publicvoid setHasNextPage(boolean hasNextPage){ U(jZf{`Mz
this.hasNextPage = hasNextPage; \~:Uj~
} :+m8~n$/
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/** 2unaK<1s
* @return B)bq@jM
* Returns the hasPrePage. HaUfTQ8
*/ \ tK{!v+
publicboolean getHasPrePage(){ APC,p,"
return hasPrePage; Y8^pgv
} 79?%g=#=
-or^mNB_z
/** b&l/)DU
* @param hasPrePage Q--VZqn
* The hasPrePage to set. .=nx5yz
*/ .Kn)sD1
publicvoid setHasPrePage(boolean hasPrePage){ :RH0.5)
this.hasPrePage = hasPrePage; z`^DQ8+\j
} ygvX}q
c~1X/,biA
/** l|O)B #
* @return Returns the totalPage. 1%;o-F@
* 99\;jz7
*/ JE<zQf( &
publicint getTotalPage(){ ;m;a"j5
return totalPage; 4|Wglri
} Kc>C$}/}$
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/** 4r&S&^
* @param totalPage Q bg,q
* The totalPage to set. }[[
*/ Gl1Qbd0
publicvoid setTotalPage(int totalPage){ P?y3YxS
this.totalPage = totalPage; : *~}\M*
} lR^OS*v
M%3 \]&
} fcuU,A
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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 @wy&Z
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个PageUtil,负责对Page对象进行构造: H9x,C/r,
java代码: ha;Xali ]
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/*Created on 2005-4-14*/ N(%%bHi#V
package org.flyware.util.page; \WDL?(G<
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import org.apache.commons.logging.Log; =aWj+ggd@
import org.apache.commons.logging.LogFactory; $#cZJ@;]
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/** >t[beRcR6
* @author Joa JJ50(h)U
* [3yzVcr~4
*/ MWsjkI`
publicclass PageUtil { :QndeUw
p)t1]<,Of
privatestaticfinal Log logger = LogFactory.getLog K/2k/\Jk[_
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(PageUtil.class); `]Uu` b
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/** +<G |Ru-
* Use the origin page to create a new page (1
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* @param page B? Vr9H 7n
* @param totalRecords B8jSdlvz
* @return ~wMdk9RQ
*/ 'IorjR@40
publicstatic Page createPage(Page page, int L[]*vj
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%
totalRecords){ ;XJK*QDN
return createPage(page.getEveryPage(), !)jw o=l}J
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page.getCurrentPage(), totalRecords); Qy)+YhE
} IL:d`Kbqf
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/** ZP@or2No%
* the basic page utils not including exception 4G:I VK9
$Hx00
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handler j\^0BTZ
* @param everyPage yIab3/#`
* @param currentPage a@|/D\C
* @param totalRecords |-WoR u
* @return page L<kIzB !
*/ s6#@S4^=\
publicstatic Page createPage(int everyPage, int D;f[7Cac
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currentPage, int totalRecords){ HT]v S}s
everyPage = getEveryPage(everyPage); 0p8Z l
currentPage = getCurrentPage(currentPage); ,BK6a'1J
int beginIndex = getBeginIndex(everyPage, p^2"g~
p*11aaIbp~
currentPage); :NB,Dz+i
int totalPage = getTotalPage(everyPage, CaX0Jlk*
Gj[+{
totalRecords); OH.Re6Rr
boolean hasNextPage = hasNextPage(currentPage, 0-)D`s%
q<Zdf
totalPage); -ff|Xxar{
boolean hasPrePage = hasPrePage(currentPage); Mo+mO&B
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returnnew Page(hasPrePage, hasNextPage, T5mdC
everyPage, totalPage, / 38b:,
currentPage, o8!gV/oy
!J34yro+s
beginIndex); M`W%nvEDE
} NF&
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privatestaticint getEveryPage(int everyPage){ Yp8~wdm
return everyPage == 0 ? 10 : everyPage; S.;>:Dd[K
} #!IezvWf
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privatestaticint getCurrentPage(int currentPage){ ^wL
n
return currentPage == 0 ? 1 : currentPage; +k!Y]_&(:f
} \]y4e^FZZ
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privatestaticint getBeginIndex(int everyPage, int '4PAH2&n
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currentPage){ ;4jRsirx9
return(currentPage - 1) * everyPage; ?Rc+H;x=f
} ^*7~ Wxk5
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privatestaticint getTotalPage(int everyPage, int ;T0Y=yC
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totalRecords){ dzYB0vut@
int totalPage = 0; c65_E<5Z
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if(totalRecords % everyPage == 0) c5uT'P"
totalPage = totalRecords / everyPage; b\zRwp
else Z+!3m.q
totalPage = totalRecords / everyPage + 1 ; BX[92~Bq
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return totalPage; "ei*iUBN:
} _=c>>X
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privatestaticboolean hasPrePage(int currentPage){ iST r;>A
return currentPage == 1 ? false : true; Jji~MiMn
} sQ65QJtt0A
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privatestaticboolean hasNextPage(int currentPage, |irqv< r
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int totalPage){ 7@g8nv(p
return currentPage == totalPage || totalPage == GS |sx
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0 ? false : true; DPvM|n`TW
} .xT8@]
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} `nccRy<l
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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。 [h 8j0Q@Q
37)Dx
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 hd~X c
~je#gVoUR
做法如下: l-"c-2-!
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 @sly-2{e1
7s_#X|A$
的信息,和一个结果集List: :8}QKp
java代码: .op:
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/*Created on 2005-6-13*/ *>!O2c
package com.adt.bo; JicAz1P1W
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import java.util.List; HlqvXt\
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import org.flyware.util.page.Page; $: "r$7
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/** I*R[8|
* @author Joa 3*$A;%q
*/ <=8REA?
publicclass Result { ZSq7>}
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private Page page; }}XYV eI
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private List content; -x2/y:q `
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/** 7
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* The default constructor 6>v`6
*/ lk{
public Result(){ ";38vjIV
super(); G?!b00H
} v5l)T}Nb
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/** tVd\ r"0k
* The constructor using fields zu&5[XL
* SCE5|3j
* @param page /]_T
* @param content 8<M'~G%CEq
*/ Ar4E $\W
public Result(Page page, List content){ ;T~]|#T\6
this.page = page; VO3&