Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 D^s0EW-E
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Px7g\[]
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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 T{H#]BF<E
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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 #8f"}>U9.,
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分页支持类: lzy$.H"W
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java代码: VtzmY
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package com.javaeye.common.util; 9poEUjBI
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import java.util.List; "p~]m~g
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publicclass PaginationSupport { t6%xit+
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publicfinalstaticint PAGESIZE = 30; J ]Gc
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privateint pageSize = PAGESIZE; Xq^y<[
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privateList items; }M9DqZ;I
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privateint totalCount; [5p7@6:$u
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privateint[] indexes = newint[0]; ;vv!qBl|@
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privateint startIndex = 0; QVG0>,+}$
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public PaginationSupport(List items, int @maZlw1q
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totalCount){ _KM $u>B8
setPageSize(PAGESIZE); hKH$AEHEU}
setTotalCount(totalCount); Ss<_K>wk
setItems(items); d1uG[
setStartIndex(0); IGK_1@tq
} }Uwkef.Q
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public PaginationSupport(List items, int 1Oca@E\Z.
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totalCount, int startIndex){ [zh4W*K_cq
setPageSize(PAGESIZE); "\zj][sL
setTotalCount(totalCount); _Xk03\n6
setItems(items); csFJ5
setStartIndex(startIndex); 1IF'>*
} C DnR
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public PaginationSupport(List items, int }KD7 Y
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totalCount, int pageSize, int startIndex){ V6z@"+
setPageSize(pageSize); wHt#'`5
setTotalCount(totalCount); KT
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setItems(items); *m| t=9E
setStartIndex(startIndex); D*XZT{1g
} |>IUtUg\
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publicList getItems(){ Ukh$`q}
return items; ER;lkF`RF
} nqurY62Ip
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publicvoid setItems(List items){ N
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this.items = items; ~`~%(DA=
} .o\;,l2
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publicint getPageSize(){ clq~ ;hx
return pageSize; DYT@BiW{
} yBPt%EF
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publicvoid setPageSize(int pageSize){ \8>
this.pageSize = pageSize; 0\EpH[m}-
} bRK CY6
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publicint getTotalCount(){ R8=I)I-8
return totalCount; ?ae[dif
} 4]DAh
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publicvoid setTotalCount(int totalCount){ rR,+G%[(=4
if(totalCount > 0){ F=-uDtQ<N
this.totalCount = totalCount; TbKP8zw{
int count = totalCount / O?nPxa<
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pageSize; |<j,Tr1[
if(totalCount % pageSize > 0) !"`@sd~
count++; 7x[LF ^o
indexes = newint[count]; 7d|*postv
for(int i = 0; i < count; i++){ x9x#'H3
indexes = pageSize * .])>A')r
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i; .%x"t>]
} `2B*CMW{
}else{ i\kTm?BQZ
this.totalCount = 0; F,p`-m[q
} DEUd[
} `G=ztL!gq
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publicint[] getIndexes(){ toS(UM n
return indexes; ;Pol#0_(
} E3~,+68U
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publicvoid setIndexes(int[] indexes){ Kcscz,
this.indexes = indexes; %sO Wg.0_
} 5u2{n rc
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publicint getStartIndex(){ )z2|"Lp
return startIndex; 5y1or
} kq) +@p
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publicvoid setStartIndex(int startIndex){ u @{E{
if(totalCount <= 0) pY+.SuM
this.startIndex = 0; 7ei>L]gm%
elseif(startIndex >= totalCount) Q!4i_)rM
this.startIndex = indexes Qqd6.F
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[indexes.length - 1]; {l&Ltruhz
elseif(startIndex < 0) l^DINZU@
this.startIndex = 0; (Oxz'#TX
else{ A[u)wX^`f^
this.startIndex = indexes Vk MinE
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[startIndex / pageSize]; v-P8WFjca
} 9
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} !MZ+- dpK
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publicint getNextIndex(){ G{@C"H[$<
int nextIndex = getStartIndex() + :7 qqjs
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pageSize; zq,iLoY[R
if(nextIndex >= totalCount) iP<k1#k
return getStartIndex(); BQyvj\uJ
else j y7
return nextIndex; 'M~BE\
} Ze-MAt
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publicint getPreviousIndex(){ aQ(`6DQv
int previousIndex = getStartIndex() - Z} c'Bm(
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pageSize;
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if(previousIndex < 0) EoKC8/
return0; z7-`Y9Ypd
else +O)]^"TG
return previousIndex; .
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} g d z
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} lkV6qIj
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抽象业务类 VBu8}}Ql
java代码: z)5S^{(
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/** Hl4\M]]/&
* Created on 2005-7-12 ddoST``G
*/ M(qxq(#{U
package com.javaeye.common.business; PKi_Zh.D
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import java.io.Serializable; Z`rK\Bc
import java.util.List; >4,{6<|
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import org.hibernate.Criteria; 'nMApPl
import org.hibernate.HibernateException; A^pu
import org.hibernate.Session; p?;-!TUv
import org.hibernate.criterion.DetachedCriteria; ;_iPm?Y8
import org.hibernate.criterion.Projections; -<_7\09
import ue@8voZhS/
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org.springframework.orm.hibernate3.HibernateCallback; ,*7H|de7
import Am=wEu[b
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org.springframework.orm.hibernate3.support.HibernateDaoS WNhbXyp_
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upport; w TlGJ$D0
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import com.javaeye.common.util.PaginationSupport; 'V&2Xvl%
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public abstract class AbstractManager extends \yM-O- {
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HibernateDaoSupport {
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privateboolean cacheQueries = false; K'NcTw#f
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privateString queryCacheRegion; Yb}w;F8(
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publicvoid setCacheQueries(boolean 6_*!|g
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cacheQueries){ N=#4L$@-
this.cacheQueries = cacheQueries; Id%_{),HX
} }&1Iyb
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publicvoid setQueryCacheRegion(String yLW/ -%I#u
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queryCacheRegion){ va5FxF*%
this.queryCacheRegion = _Fizgs
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queryCacheRegion;
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} =O,JAR"ug
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publicvoid save(finalObject entity){ Z v4<b
getHibernateTemplate().save(entity); !h>D;k6 e
} R uLvG+
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publicvoid persist(finalObject entity){ J='W+=N
getHibernateTemplate().save(entity); 0N{+y}/G
} i&A%"lOI9
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publicvoid update(finalObject entity){ .|uLt J
getHibernateTemplate().update(entity); 5@ foxI
} :M j_2
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publicvoid delete(finalObject entity){ ?>V6P_r>
getHibernateTemplate().delete(entity); Tr&E4e
} o'Pu'y
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publicObject load(finalClass entity, 6Nt$ZYS
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finalSerializable id){ #.<V^
return getHibernateTemplate().load 6^;^rUlm
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(entity, id); <qhBc:kc
} .Pw%DZ'
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publicObject get(finalClass entity, nLy#|C
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finalSerializable id){ se!mb _!
return getHibernateTemplate().get }>&KUl
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(entity, id); ;LRW
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} M$A#I51
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publicList findAll(finalClass entity){ %jEY3q
return getHibernateTemplate().find("from <tbZj=*O/o
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" + entity.getName()); 9cd 8=][
} aV>aiR=
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publicList findByNamedQuery(finalString Q>8pP \ho
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namedQuery){ 5j{Np,K
return getHibernateTemplate r7 VXeoX
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().findByNamedQuery(namedQuery); s
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} n|i"S`
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publicList findByNamedQuery(finalString query, ++8_fgM
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finalObject parameter){ +;q.Y?
return getHibernateTemplate H9`
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().findByNamedQuery(query, parameter); )ofm_R'q*
} #tjmWGo,
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publicList findByNamedQuery(finalString query, :eOR-}p'
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finalObject[] parameters){ M3pjXc<O
return getHibernateTemplate f vLC_'M
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().findByNamedQuery(query, parameters); }Qrab#v
} WM,i:P)b
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publicList find(finalString query){ ~p*1:ij
return getHibernateTemplate().find ],lV}Mlg*
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(query); },c,30V'
} IfV
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publicList find(finalString query, finalObject 4;KWG}~[o
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parameter){ :\yc*OtX
return getHibernateTemplate().find u3ZCT" !
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(query, parameter); pCU*@c!
} I^3:YVR&
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public PaginationSupport findPageByCriteria 61_f3S(u
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(final DetachedCriteria detachedCriteria){ ~`eHHgX
return findPageByCriteria }/e`v6
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 9z ?7{2C
} ;(6P6@+o
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public PaginationSupport findPageByCriteria |n6Eg9
*'R#4@wmP
(final DetachedCriteria detachedCriteria, finalint A0xC,V~z
~
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startIndex){ &L4
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return findPageByCriteria J]pa4C`
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(detachedCriteria, PaginationSupport.PAGESIZE, ULBg{e?l8
)`HA::
startIndex); Vhg1/EgUr
} $Ui&D
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public PaginationSupport findPageByCriteria jo98
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(final DetachedCriteria detachedCriteria, finalint qpqokK
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pageSize, Q M1F?F
finalint startIndex){ +S~.c;EK
return(PaginationSupport) {G*QY%j^
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getHibernateTemplate().execute(new HibernateCallback(){ M{N(~ql
publicObject doInHibernate 6Nh0
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]
(Session session)throws HibernateException { i$UQbd
Criteria criteria = HJhH-\{@
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detachedCriteria.getExecutableCriteria(session); .~klG&>aV
int totalCount = ;D2E_!N
dt
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((Integer) criteria.setProjection(Projections.rowCount uS5o?fg\e
j9y3hQ+q
()).uniqueResult()).intValue(); ?IYY'fS"
criteria.setProjection #a9_~\s
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(null); OX hAha`R
List items = TbhH&kG)1
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criteria.setFirstResult(startIndex).setMaxResults MagMZR
7_\Mwy{P
(pageSize).list(); g+[kde;(^
PaginationSupport ps = kv?|'DN
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new PaginationSupport(items, totalCount, pageSize, 9$l>\.6
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startIndex); n2ndjE$
return ps; 0SV \{]2
} `
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}, true); ,x_Z JL
} JW+*d`8Z[
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public List findAllByCriteria(final rVryt<2:@r
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DetachedCriteria detachedCriteria){ XZph%j0o
return(List) getHibernateTemplate sbsu(Sz+
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().execute(new HibernateCallback(){ $Ua56Y
publicObject doInHibernate s#-eN)1R
t#~?{i@m
(Session session)throws HibernateException { F@vbSFv)/
Criteria criteria = 3 <SqoJSp
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detachedCriteria.getExecutableCriteria(session); 'K@0Wp
return criteria.list(); _sMs}?^
} ,4@|1z{bfm
}, true); LAs7>hM
} E5G{B'%j
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public int getCountByCriteria(final /iM$Tb5
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DetachedCriteria detachedCriteria){ ?y7w} W
Integer count = (Integer) 3<(q }
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getHibernateTemplate().execute(new HibernateCallback(){ \8b6\qF/\
publicObject doInHibernate ;e s^R?z
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(Session session)throws HibernateException { Ex(3D[WmMW
Criteria criteria = \M+L3*W
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detachedCriteria.getExecutableCriteria(session); Ka-p& Uv1<
return `~F5wh~
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criteria.setProjection(Projections.rowCount r6.N4eW.L
4\2V9F{s
()).uniqueResult(); |!*Xl)
]
} ^PqF<d6
}, true); +V8b
return count.intValue(); 2VgP
} j
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} (.X]F_*sc
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用户在web层构造查询条件detachedCriteria,和可选的 "^rNr_
wyY*:{lZ
startIndex,调用业务bean的相应findByCriteria方法,返回一个 o'=VZT9
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PaginationSupport的实例ps。 isK;mU?<
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ps.getItems()得到已分页好的结果集 pB01J<@m
ps.getIndexes()得到分页索引的数组 +"!aM?o
ps.getTotalCount()得到总结果数 B;t=B_oK
ps.getStartIndex()当前分页索引 E_:QSy5G
ps.getNextIndex()下一页索引 ]T<^{jG
ps.getPreviousIndex()上一页索引 Dn;p4T@
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- r#K#v3
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Y7Gs7
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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 XD%wj
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一下代码重构了。 284zmZZ
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我把原本我的做法也提供出来供大家讨论吧: <y=ovkM3
PZOKrW
首先,为了实现分页查询,我封装了一个Page类: a(x?fa[D
java代码: v3^|"}\q5
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/*Created on 2005-4-14*/ ^eh/HnJs
package org.flyware.util.page; HnZPw&*
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/** <^><3U`
* @author Joa bLS&H[fK
* m_lrPY-
*/ v'ay.oVzw
publicclass Page { =>LZm+P
RU_L<Lpi
/** imply if the page has previous page */ ME+em1ZH
privateboolean hasPrePage; S+I^!gT
AV4~U:vU
/** imply if the page has next page */ dHII.=lT
privateboolean hasNextPage; ycpE=fso'
l4T:d^Eb
/** the number of every page */ |E^|X!+9
privateint everyPage; WZ~> BM
fI:H8
/** the total page number */ b9("DZW;
privateint totalPage; \
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; B$*)X9
/** the number of current page */ L.)yXuo4
privateint currentPage; >)c9|e=8
d-$_|G+
/** the begin index of the records by the current ]+%=@mWYs
77aX-e*=E
query */ +{-]P\oc
privateint beginIndex; >FFVY{F
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/** The default constructor */ ^.HWkS`e
public Page(){ c> ~:dcy
P. V\ov7m2
} JAP(|
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/** construct the page by everyPage |uUuFm
* @param everyPage |]ucHV
* */ )f*Iomp]@
public Page(int everyPage){ }76.6=~
this.everyPage = everyPage; kk_zVrQ<
} ,wK 1=7
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/** The whole constructor */ !J^tg2M8:
public Page(boolean hasPrePage, boolean hasNextPage, *cNk>y
7),*3c ')
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int everyPage, int totalPage, O
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int currentPage, int beginIndex){ B,y3]
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this.hasPrePage = hasPrePage; -!R
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this.hasNextPage = hasNextPage; &?T ${*~
this.everyPage = everyPage; /hci\-8N~
this.totalPage = totalPage; ?5~!i9pY
this.currentPage = currentPage; JDhwN<0R
this.beginIndex = beginIndex; 9d\N[[Vu]R
} L82NP)St
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/** h48 bb.p2
* @return E .;io*0
* Returns the beginIndex. F#1kZ@nq
*/ {B^pnLc
publicint getBeginIndex(){ [%~NM/xu<
return beginIndex; shK&2Noan
} \=g!$
%ck`0JZAP
/** wAz,vq=x
* @param beginIndex 78w4IICk
* The beginIndex to set. -\,VGudM}
*/ ^[TOZXL`:
publicvoid setBeginIndex(int beginIndex){ *k6$
this.beginIndex = beginIndex; (Y;'[.
} P>W8V+l![
i'HST|!j
/** uI9lK
* @return +Ag#B*
* Returns the currentPage. k2uBaj]
*/ t>oM%/H
publicint getCurrentPage(){ 0UjyMEiK
return currentPage; Q)dT(Td9~
} %kW3hQ<$
qKs7WBRJy
/** Q9q9<J7j$
* @param currentPage FB!z#Eim
* The currentPage to set. va+m9R0
*/ =n)#!i
publicvoid setCurrentPage(int currentPage){ rgn|24x
this.currentPage = currentPage; h7RD`k:mF
} P^;WB*V
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/** n}5x-SxS0
* @return _w%s(dzk
* Returns the everyPage. B>aEHb
*/ !vrnoFVu
publicint getEveryPage(){ VY{,x;O`
return everyPage; nOr"K;C
} v1K4 $&{F
.m'N7`VB
/** c8\g"T
* @param everyPage L]NYYP-
* The everyPage to set. 3H <`Z4;
*/ gQCC>8
publicvoid setEveryPage(int everyPage){ C=EhY+5
this.everyPage = everyPage; Oo$%Yh51~
} eo]a'J9(
x"!#_0TT}
/** %9.bu|`KK
* @return :n`0)g[(
* Returns the hasNextPage. b@F_7P%
*/ <H_LFrB$W
publicboolean getHasNextPage(){ WMA*.$Zi
return hasNextPage; wEv*1y4
} rl41#6
a6 * Y%?
/** {cX7<7N
* @param hasNextPage B8>FCF&}E
* The hasNextPage to set. 2nYiG)tg
*/ roL]v\tr
publicvoid setHasNextPage(boolean hasNextPage){ s'2y%E#
this.hasNextPage = hasNextPage; &U854
} ur`}v|ZY
"SDsISWd
/** AF
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* @return B1HQz@^
* Returns the hasPrePage. ),)Q{~&`
*/ {<~s&EPd
publicboolean getHasPrePage(){ W *|OOa'
return hasPrePage; Je@p5(f
} _i#@t7
Mj,2\ijNM
/** s+Cl
* @param hasPrePage n9w j[t1/
* The hasPrePage to set. FBE @pd
*/ ?|gGsm+
publicvoid setHasPrePage(boolean hasPrePage){ WMRYT"J?N]
this.hasPrePage = hasPrePage; 8UlB~fVg
} uk`d,xF
/XbY<pj
/** EgCp:L{
* @return Returns the totalPage. hE9'F(87a
* b^@`uDb6
*/ R^F7a0"
publicint getTotalPage(){ ?Of{c,2 .
return totalPage; W[@"H1bVH
} ?BXP}]
t>m8iS>
/** #r-j.f}yx
* @param totalPage 0 [*nAo
* The totalPage to set. )sMAhk|
*/ AW]("pt
publicvoid setTotalPage(int totalPage){ IZzhJK M1V
this.totalPage = totalPage; wV]sGHu F}
} 2OA8
R}
^ON-#
} ]i9H_K
CvgPIrl
HFpjNR
k
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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 LS*{]@8q
Z5{*? 2
个PageUtil,负责对Page对象进行构造: |F8;+nAVF#
java代码: $@lq}FQ%
~Q3WBOjn
}6yxt9
/*Created on 2005-4-14*/ q{jk.:;'
package org.flyware.util.page; oC^z_AtZ
|% la
import org.apache.commons.logging.Log; eYnLZ&H5O
import org.apache.commons.logging.LogFactory; k4]R]=Fh.
F&>T-u-dog
/** 6~>^pkV
* @author Joa 4Ub?*
* weTK#O0@v
*/ z{7,.S
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publicclass PageUtil { tr#)iZ\
?Xy w<fMQ
privatestaticfinal Log logger = LogFactory.getLog oxxE'cx{g
:*^(OnIe
(PageUtil.class); i2`.#YJ&v
g: H[#I
/** znGZULa#
* Use the origin page to create a new page CfazD??x
* @param page h7Shl<f
* @param totalRecords N9fUlXhR
* @return QySca(1tN
*/ <S:,`v&Z
publicstatic Page createPage(Page page, int hO:)=}+H
>@q2FSMf
totalRecords){ VO\S>kw
return createPage(page.getEveryPage(), #!K~_DL
jn5=N[hd
page.getCurrentPage(), totalRecords); uL qpbn
} oj,Vi-T Z
* wQZ'
/** q/aL8V<"z
* the basic page utils not including exception {HE.mHy
_KT]l./
handler >Gw%r1)
* @param everyPage bUZ&}(/
* @param currentPage z[<pi:
* @param totalRecords : .UX[!^
* @return page k;AV;KWI'
*/ U)T/.L{0i
publicstatic Page createPage(int everyPage, int 7csl1|U
/3"e3{uy
currentPage, int totalRecords){ @$N*lrM2
everyPage = getEveryPage(everyPage); 2={K-s20
currentPage = getCurrentPage(currentPage); q%)*,I<
int beginIndex = getBeginIndex(everyPage, =~(L JPo6
SIyS.!k>
currentPage); HY%6eUhj
int totalPage = getTotalPage(everyPage, 'J&@jp
>cU*D:
totalRecords); iNaC ZC
boolean hasNextPage = hasNextPage(currentPage, %WXVfkD
AQ_#uxI'oa
totalPage); JOL Z2
boolean hasPrePage = hasPrePage(currentPage); d}^:E
5p(t")
returnnew Page(hasPrePage, hasNextPage, P(W\aLp
everyPage, totalPage, BLYk
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currentPage, V< 9em7
O!@KM;
beginIndex); ;d'O. i=
} R4K eUn"
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privatestaticint getEveryPage(int everyPage){ nd*!`P
return everyPage == 0 ? 10 : everyPage; n"`SL<K1
} Y/Gswcz
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privatestaticint getCurrentPage(int currentPage){ _dRn0<#1(k
return currentPage == 0 ? 1 : currentPage; Lqf#,J
} FKvO7? K
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privatestaticint getBeginIndex(int everyPage, int N]P*6sf-6
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currentPage){ EJSgTtp2
return(currentPage - 1) * everyPage; E6KBpQcd[
} 5{x[EXE'
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privatestaticint getTotalPage(int everyPage, int #Z3I%bkw H
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totalRecords){ L-oPb)
int totalPage = 0; |^&2zyUj/
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if(totalRecords % everyPage == 0) 2
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totalPage = totalRecords / everyPage; B?zS_Ue
else kgI.kT(=
totalPage = totalRecords / everyPage + 1 ; 1(\I9L&J
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return totalPage; Ee?K|_\${
} OM&\Mo
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privatestaticboolean hasPrePage(int currentPage){ 5|B(K @<
return currentPage == 1 ? false : true; ]t!}D6p
} '-1jWw:8
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privatestaticboolean hasNextPage(int currentPage, 2K7:gd8Ru
aN);P>
int totalPage){ ]oZ,{Q5~
return currentPage == totalPage || totalPage == CSg5i&A=
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0 ? false : true; ( ;S]{z%
} C
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} :?of./Df|
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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%KW[v<G<
UBk
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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 U3R`mHr0
:|6D@
做法如下: d'@H@
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 #(wzl
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的信息,和一个结果集List: ?+JxQlVDt-
java代码: NBR'^6
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/*Created on 2005-6-13*/ ,IX4Zo"a
package com.adt.bo; FO)nW:8]
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import java.util.List; ^V;lZtZ
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import org.flyware.util.page.Page; Spw=+z<<Ub
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/** /r 2.j3:l
* @author Joa Env}g CX
*/ a9q?9X
publicclass Result {
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private Page page; ra#)*fG,~
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private List content; sn-+F%[
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/** i{RS/,h4
* The default constructor q9Opa2
*/ Fm+)mmJP
public Result(){ 9%'HB\A
super(); }[R@HmN
} t;PnjCD<`
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/** H"
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