Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 6dH> 0l
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 D+nKQ4
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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 ;h f{B7
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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 ES4[@RX
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分页支持类: 0:1[F!]'b
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java代码: EDDld6O,
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package com.javaeye.common.util; q PveG1+25
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import java.util.List; Ii.0Bul
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publicclass PaginationSupport { &UFj
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publicfinalstaticint PAGESIZE = 30; r(ZMZ^
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privateint pageSize = PAGESIZE; 6L/`
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privateList items; RJ+["[k
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privateint totalCount; M#u~]?hS
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privateint[] indexes = newint[0]; ZZ? KD\S5
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privateint startIndex = 0; }J ^+66{
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public PaginationSupport(List items, int >)j`Q1Qc\
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totalCount){ up;^,I
setPageSize(PAGESIZE); _{C
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setTotalCount(totalCount); Pb]EpyAW
setItems(items); { qJ(55
setStartIndex(0); x :? EL)(
} pba`FC4R
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public PaginationSupport(List items, int `
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totalCount, int startIndex){ o>l/*i0I
setPageSize(PAGESIZE); "\~d!"n|2
setTotalCount(totalCount); I1)t1%6"vJ
setItems(items); F*4zC@;
setStartIndex(startIndex); Ivx]DXR|
} }2]m]D@%7
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public PaginationSupport(List items, int GlOSCJZ
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totalCount, int pageSize, int startIndex){ Q3'L\_1L
setPageSize(pageSize); BCI[jfd 7
setTotalCount(totalCount); F@l d#O
setItems(items); A|`mIma#
setStartIndex(startIndex); 6
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} L;i(@tp|v
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publicList getItems(){ 2uzy]faM
return items; >$:_M*5
} nJ|M
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publicvoid setItems(List items){ M\D25=(
this.items = items; x>GxyVE
} le150;7
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publicint getPageSize(){ pmuT7*<19
return pageSize; DmiZ"A
} =`OnFdI
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publicvoid setPageSize(int pageSize){ `9&~fWu
this.pageSize = pageSize; y[DS$>E
} QIC? `hk1
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publicint getTotalCount(){ ^u+#x2$Mg
return totalCount; pC/13|I
} mO0}Go8
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publicvoid setTotalCount(int totalCount){ _W
if(totalCount > 0){ oqa8v6yG'
this.totalCount = totalCount; 0]Qk *u<
int count = totalCount / y7T<Auue`
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pageSize; HXb_k1n
if(totalCount % pageSize > 0) k9!euj&
count++; t8f:?
indexes = newint[count]; >9Z7l63+}
for(int i = 0; i < count; i++){ zI$'D|A
indexes = pageSize * YZZog 6%
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} lQqP4-E?
}else{ 5I&Dk4v
this.totalCount = 0; E[Bj+mX9
} $Ned1@%[
} c@x6<S%*
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publicint[] getIndexes(){ $QnsP#ePN
return indexes; 6 2LLfD
} Vtv1{/@+c
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publicvoid setIndexes(int[] indexes){ jk{m8YP)E
this.indexes = indexes; C#@-uo2
} B)BR
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publicint getStartIndex(){ }$` PZUw>
return startIndex; cuh Z_l
} jP\5bg-}
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publicvoid setStartIndex(int startIndex){ A-l[f\
if(totalCount <= 0) 4"s/T0C
this.startIndex = 0; 9.wZhcqqU
elseif(startIndex >= totalCount) FyqsFTh_
this.startIndex = indexes P-\65]`C
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[indexes.length - 1]; N6BEl55 &
elseif(startIndex < 0) I.- I4F)D
this.startIndex = 0; S{nBQB<
else{ Qov*xRO6
this.startIndex = indexes 4k)0OQeW6
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[startIndex / pageSize]; ;umbld0
} 4ah5}9{g
} P\%aJ'f~
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publicint getNextIndex(){ 5l]qhi3f
int nextIndex = getStartIndex() + [tkP2%1
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pageSize; =%d.wH?dZ/
if(nextIndex >= totalCount) 9>/:c\q+
return getStartIndex(); 'H(khS
else :8U@KABH@h
return nextIndex; $pajE^d4V
} TTJj=KPA
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publicint getPreviousIndex(){ 1"No~/_
int previousIndex = getStartIndex() - $9ys!
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pageSize; kudXwj
if(previousIndex < 0) hR,5U=+M7
return0; |XJ|vQGU
else 2XrYm"6w
return previousIndex; zKQXmyO
} a"8H(HAlNn
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} Ebp=du
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抽象业务类 _f@nUv*
java代码: ddEV@2F
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/** Dyh|F\T
* Created on 2005-7-12 S'=}eeG
*/ yUvn h
package com.javaeye.common.business; RP%FMb}nt
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import java.io.Serializable; _*n
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import java.util.List; J#?z/ 3v(
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import org.hibernate.Criteria; WNF#eM?[a
import org.hibernate.HibernateException; Zn6u6<O=
import org.hibernate.Session; < mp_[-c
import org.hibernate.criterion.DetachedCriteria; !"dAwG?S
import org.hibernate.criterion.Projections; u_6x{",5I
import t>eeOWk3
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org.springframework.orm.hibernate3.HibernateCallback; Xn%O .yM6
import r tH
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org.springframework.orm.hibernate3.support.HibernateDaoS KdC'#$
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upport; {11xjvAD
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import com.javaeye.common.util.PaginationSupport; nc;iJ/\4
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public abstract class AbstractManager extends VTK +aI
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HibernateDaoSupport { #1Iev7w
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privateboolean cacheQueries = false;
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privateString queryCacheRegion; H.&"~eH
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publicvoid setCacheQueries(boolean fiW2m=h_
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cacheQueries){ 4c@_u8
this.cacheQueries = cacheQueries; x2tcr+o
} &+ UnPE(
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publicvoid setQueryCacheRegion(String K?*p|&Fi?8
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queryCacheRegion){ *z)+'D*+
this.queryCacheRegion = N[kl3h%q
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queryCacheRegion; (= Wu5H
} =,Z5F`d4
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publicvoid save(finalObject entity){ Wcki=ac\v!
getHibernateTemplate().save(entity); x| r#
} .qrS[ w
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publicvoid persist(finalObject entity){ na_Wp^;
getHibernateTemplate().save(entity); t""d^a#Dp
} yQ| V7G
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publicvoid update(finalObject entity){ yHn8t]{
getHibernateTemplate().update(entity); qE M,~:lTn
} G!7A]s>C
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publicvoid delete(finalObject entity){ fkD-mRKw
getHibernateTemplate().delete(entity); ';I(#J6
} CIAKXYM
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publicObject load(finalClass entity, + {WZpP},v
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finalSerializable id){ :b<<
return getHibernateTemplate().load 0iVeM!bM
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(entity, id); U,Th-oU
} /~P4<1
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publicObject get(finalClass entity, r=<1*u
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finalSerializable id){ .B{:<;sa
return getHibernateTemplate().get f9^MLb6)
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(entity, id); Aq_?8 Cd
} @m9dB P
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publicList findAll(finalClass entity){ IY}{1[<N
return getHibernateTemplate().find("from _vUId?9@+e
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" + entity.getName()); @[~j|YH}
} >[4CQK`U
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publicList findByNamedQuery(finalString q5~"8]Dls
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namedQuery){ QPKY9.Rvv
return getHibernateTemplate *OHaqe(*
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().findByNamedQuery(namedQuery); '[Bok=$B)
} h&x;#.SYK
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publicList findByNamedQuery(finalString query, IQ5'4zQg=
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finalObject parameter){ )V9wU1.
return getHibernateTemplate nS]Ih 0(K
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().findByNamedQuery(query, parameter); +7j7zpw
} WTwura,
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publicList findByNamedQuery(finalString query, 3($tD*!o
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finalObject[] parameters){ _p0G8
return getHibernateTemplate 3mT6HGSKR
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().findByNamedQuery(query, parameters); 4AYW'j C
} sNsWz.DLT#
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publicList find(finalString query){ &o7"L;
return getHibernateTemplate().find X"S")BQ
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(query); bjql<x5d
} aR}I l&
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publicList find(finalString query, finalObject j9*5Kj
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parameter){ "T~A*a^
return getHibernateTemplate().find 2(25IYMS8
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(query, parameter); =[YjIWr#o
} /8LTM|(
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public PaginationSupport findPageByCriteria `bjPOA(g
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(final DetachedCriteria detachedCriteria){ "\rR0V!wA
return findPageByCriteria E6clVa
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 9zlhJ7i
} [cw>; \J
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public PaginationSupport findPageByCriteria oe{,-<yck
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(final DetachedCriteria detachedCriteria, finalint (XQ:f|(
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startIndex){ /N=M9i\;
return findPageByCriteria SD]rYIu+
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(detachedCriteria, PaginationSupport.PAGESIZE, q uiX"lV(
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startIndex); Z6_fI
} d5qGTT ~a
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public PaginationSupport findPageByCriteria ""x>-j4
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(final DetachedCriteria detachedCriteria, finalint ^2"3h$DJfS
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pageSize, ]I(<hDuRp
finalint startIndex){ vec4R )S
return(PaginationSupport) 4/Xu,pT
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getHibernateTemplate().execute(new HibernateCallback(){ ONm-zRx|
publicObject doInHibernate 6U%F
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(Session session)throws HibernateException { ETrL3W<
Criteria criteria = %)P)Xb
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detachedCriteria.getExecutableCriteria(session); mEq>{l:
int totalCount = UiH5iZ<r;
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((Integer) criteria.setProjection(Projections.rowCount .pPtBqp
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()).uniqueResult()).intValue(); (\CH;c-@
criteria.setProjection jF|LPWl
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(null); 0hCUr]cZ,
List items = /H :Bu
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criteria.setFirstResult(startIndex).setMaxResults RW^e#z>m"E
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(pageSize).list(); c<imqDf
PaginationSupport ps = z?.XVk-
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new PaginationSupport(items, totalCount, pageSize, bipA{VU
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startIndex); xH{V.n&v
return ps;
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} KBwY _
}, true); ]RTK:%
} z_A34@a
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public List findAllByCriteria(final o;'-^ LJ
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DetachedCriteria detachedCriteria){ oE$zOS&2
return(List) getHibernateTemplate :}[D;cx
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().execute(new HibernateCallback(){ aIklAj)=
publicObject doInHibernate Rj~y#m
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(Session session)throws HibernateException { 7WEoyd
Criteria criteria = t[X,m]SX
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detachedCriteria.getExecutableCriteria(session); fP;2qho
return criteria.list(); ZG1 {"J/z
} 2GJp`2(%dA
}, true); Ls{]ohP
} y.?Q
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public int getCountByCriteria(final K"g`,G6S
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DetachedCriteria detachedCriteria){ d?>pcT)G_
Integer count = (Integer) .
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getHibernateTemplate().execute(new HibernateCallback(){ )/uCdSDIc
publicObject doInHibernate {z7kW@c
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(Session session)throws HibernateException { ./Wi(p{F
Criteria criteria = ?oQAxb&
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detachedCriteria.getExecutableCriteria(session); 7hfa?Mcz
return R1C2d +L
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criteria.setProjection(Projections.rowCount I8LoXY
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()).uniqueResult(); m9Hdg^L
} 77~l~EX
}, true); K]yUPx
return count.intValue(); KhPDkD-
} KAm$^N5
} x*0mmlCb
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用户在web层构造查询条件detachedCriteria,和可选的 SAGECK[Ix
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 U$T
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PaginationSupport的实例ps。 e7JZk6GP#9
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ps.getItems()得到已分页好的结果集 E]%&)3O[
ps.getIndexes()得到分页索引的数组 q%c"`u/v/
ps.getTotalCount()得到总结果数 3k5F$wf
ps.getStartIndex()当前分页索引 GM>Ms!Y
ps.getNextIndex()下一页索引 e%.|PZ)
ps.getPreviousIndex()上一页索引 HD9+4~8
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 _dynqF8*
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 hwdZP=X
KfMaVU=4P
一下代码重构了。 j!hdi-aTU
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我把原本我的做法也提供出来供大家讨论吧: ,P$Crs[
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首先,为了实现分页查询,我封装了一个Page类: `~ {0
java代码: L*Q#!_K0P
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/*Created on 2005-4-14*/ _33YgO
package org.flyware.util.page; _chX
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/** .GNl31f0
* @author Joa _U/C G<n
* rc)vVv
*/ J-+p]xG
publicclass Page { /d]{ #,k
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/** imply if the page has previous page */ _4MT,kN
privateboolean hasPrePage; :h60
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/** imply if the page has next page */ Yeb-u+23
privateboolean hasNextPage; 0@*EwI
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/** the number of every page */ fN{JLp
privateint everyPage; l/o
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R7-+@
/** the total page number */ FV W&)-I
privateint totalPage; O^yDb
}wR&0<HA
/** the number of current page */ lpHz*NZ0
privateint currentPage; u&s>UkR
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/** the begin index of the records by the current b_xGCBC
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query */ nPo YjQi
privateint beginIndex; E<
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/** The default constructor */ ums*EKjs97
public Page(){ j,i>
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} #{oGmzG!
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/** construct the page by everyPage dqo&3^px
* @param everyPage A%dI8Z,
* */ #Mmr{4m
public Page(int everyPage){ v$i[dZSN[
this.everyPage = everyPage; "I`g(q#Uo
} wUBug
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/** The whole constructor */ <764|q
public Page(boolean hasPrePage, boolean hasNextPage, yM-3nwk
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int everyPage, int totalPage, )>~d`_$dt
int currentPage, int beginIndex){ ( [m[<
this.hasPrePage = hasPrePage; )/2J|LxS
this.hasNextPage = hasNextPage; Fi!XaO
this.everyPage = everyPage; ss>p
this.totalPage = totalPage; |g}~7*+i
this.currentPage = currentPage; #X?#v7i",D
this.beginIndex = beginIndex; m? #J`?E
} ?IHa>f:
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/** V]I+>Zn| 7
* @return (D5.NB%@
* Returns the beginIndex. _pS!sY~d
*/ 7y2-8eL
publicint getBeginIndex(){ (<:mCPk(~
return beginIndex; k%S;N{Qh@
} b`Agb<x"
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/** AD/7k3:
* @param beginIndex ~56F<=#,
* The beginIndex to set. jWL;ElM'
*/ a="\?L5
publicvoid setBeginIndex(int beginIndex){ q
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this.beginIndex = beginIndex; L=9w
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} Ivue"_i;!
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/** _YM]U`*
* @return P:8P>#L
* Returns the currentPage. HD&Ag
*/ d|c>Y(
publicint getCurrentPage(){ @rT}V>2I
return currentPage; vx&jI$t8
} A(#4$}!n5
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/** wmf#3"n
* @param currentPage ?()$imb*
* The currentPage to set. M~/R1\'&j
*/ ,\cO>y@
publicvoid setCurrentPage(int currentPage){ 5QoU&Hv
this.currentPage = currentPage; GE0,d
} etHkyF
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/** NtnKS@Ht
* @return yA#-}Y|]b
* Returns the everyPage. >
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*/ wK[Xm'QTPJ
publicint getEveryPage(){ xf?6_=
return everyPage; t:h~p-&QB
} B1C"F-2d
$sX X6K),
/** H#+?)<UQ
* @param everyPage (i*;V0
* The everyPage to set. c8
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*/ d].(x)|st
publicvoid setEveryPage(int everyPage){ Gap\~Z@L
this.everyPage = everyPage; ' Oe}Ja
} "ccP,#Y
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/** +UTs2*H/^
* @return u3>Dvl@
* Returns the hasNextPage. s{]2~Z^2od
*/ a#qC.,$A
publicboolean getHasNextPage(){ edW:(19}
return hasNextPage; Z}
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} 0f<$S$~h
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/** D\H)uV`
* @param hasNextPage a &89K
* The hasNextPage to set. &74*CO9B9
*/ l$s8O0-'T
publicvoid setHasNextPage(boolean hasNextPage){ 'n)]"G|
this.hasNextPage = hasNextPage; ]_ON\v1
} :$#";t|
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/** I>jDM
* @return ?\l@k(w4[x
* Returns the hasPrePage. @6roW\'$
*/ HP
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publicboolean getHasPrePage(){ A]FjV~PB
return hasPrePage; #q5
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} @zHTKi`
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/** o1"-x
* @param hasPrePage v_zVhEtY
* The hasPrePage to set. +$YluGEJ
*/ #(5hV7i
publicvoid setHasPrePage(boolean hasPrePage){ u\JYxNj1
this.hasPrePage = hasPrePage; MJ)aY2
} Po=@
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/** h xCt[G@
* @return Returns the totalPage. H#LlxD)q
* $ 4&
)
*/ laQM*FLg
publicint getTotalPage(){ X8Xw'
return totalPage; 5V^+;eO
} \Q5Jg
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/** $g?`yE(K
* @param totalPage 3%JPJuNVw
* The totalPage to set. m R3km1T
*/ n;eK2+}]
publicvoid setTotalPage(int totalPage){ wV9[Jl\Z
this.totalPage = totalPage; Q0}Sju+HX
} YMSA[hm
wd/"! A4(
} 5 GP,J,J
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 tyH*epanw
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个PageUtil,负责对Page对象进行构造: Ny.s
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java代码: F`3J=AJOJ
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/*Created on 2005-4-14*/ V=@M!;'<
package org.flyware.util.page; )T=cd
;34 m!\N5
import org.apache.commons.logging.Log; vB :_|B
import org.apache.commons.logging.LogFactory; ,DHiM-v
4;*o}E
/** {hr+ENgV
* @author Joa R9/(z\'}
* `xO9xo#
*/ ?W %9H\;
publicclass PageUtil { %U.aRSf/
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privatestaticfinal Log logger = LogFactory.getLog oWZbfR9R
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(PageUtil.class); k-v@sb24_
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/** *uLlf'qU]
* Use the origin page to create a new page i_? S#L]h
* @param page G|Du/XYh
* @param totalRecords M``I5r*cg
* @return CywQ
*/ 6NO_S
publicstatic Page createPage(Page page, int Zz\e:/
fR=B/`
totalRecords){ 6o_t;cpT
return createPage(page.getEveryPage(), TZT1nj"n
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page.getCurrentPage(), totalRecords); |kHPk)}I]
} _$+lyea
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/** FM c9oyU~
* the basic page utils not including exception 50:$km\
-! dL
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handler a!1\,.
* @param everyPage kp~@Ub
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* @param currentPage 5z8!Nmb/
* @param totalRecords BPoY32d"_
* @return page F+Qp
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*/ >g+ogwZ
publicstatic Page createPage(int everyPage, int xwwy9:ze*l
J~0_
currentPage, int totalRecords){ >-s\$8En'
everyPage = getEveryPage(everyPage); *Ge2P3
currentPage = getCurrentPage(currentPage); D(MolsKc?
int beginIndex = getBeginIndex(everyPage, ?lh
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currentPage); L}bS"=B[&W
int totalPage = getTotalPage(everyPage, ,qj
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totalRecords); ,FvBZ.4c3=
boolean hasNextPage = hasNextPage(currentPage, :
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totalPage); : -@o3Syg
boolean hasPrePage = hasPrePage(currentPage); ^K4#_H#"
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returnnew Page(hasPrePage, hasNextPage, aj1o
everyPage, totalPage, >Lh+(M;+F
currentPage, F[Dhj,C"
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beginIndex); ,[To)x5o
} a *n^(
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privatestaticint getEveryPage(int everyPage){ L{K:XiPn
return everyPage == 0 ? 10 : everyPage; {2`:7U~|
} 1M|DaAI
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privatestaticint getCurrentPage(int currentPage){ -r9G5Z!|n
return currentPage == 0 ? 1 : currentPage; x0ZEVa0`4
} p{knQ],
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privatestaticint getBeginIndex(int everyPage, int RO-ABFEi(
i-(^t1c
currentPage){ qB`zyd8yu
return(currentPage - 1) * everyPage; #`tn:cP
} g?qh
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privatestaticint getTotalPage(int everyPage, int [vuqH:Ln
K)|#FRPM u
totalRecords){ 6{rH|Z
int totalPage = 0; $?^#G8J
?@"B:#l
if(totalRecords % everyPage == 0) #GBe=tm\K
totalPage = totalRecords / everyPage; 8~QEJW$
else #P,mZ}G\
totalPage = totalRecords / everyPage + 1 ; *R17 KMS
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return totalPage; eGrC0[SH
} -G<$wh9~3
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privatestaticboolean hasPrePage(int currentPage){ @\,WJmW
return currentPage == 1 ? false : true; V j\1HQ
} .6Swc?
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privatestaticboolean hasNextPage(int currentPage, g{&a|NU^
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int totalPage){ B_w;2ZuA
return currentPage == totalPage || totalPage == m^dKww
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0 ? false : true; bP%0T++vo
} Hcw@24ic
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} wv>uT{g#
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30 VvZb
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 g:/l5~b
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面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 k>
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' bio:1
做法如下: \ /C-e
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 .@#i
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的信息,和一个结果集List: WDr'w'
java代码: ^Z7])arA
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/*Created on 2005-6-13*/ ?pdvFM
package com.adt.bo; 7bioLE
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import java.util.List; t?p[w&@M2
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import org.flyware.util.page.Page; b?-Ep?G'\
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/** 7_ g}t!b`
* @author Joa hv
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*/ yyJ4r}TE
publicclass Result { _K{hq<g
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private Page page; JF]HkH_u
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private List content; YC\~PVG
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/** <7TE[M'
* The default constructor 5KJN](x+
*/ Rt{qbM|b&
public Result(){ 0}]k>ndT
super(); p{7"a
} \;x+KD
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/**
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* The constructor using fields ckRWVw
* %RgCU$s[>
* @param page c;l
d
* @param content ?#^(QR|/
*/ :`6E{yfM
public Result(Page page, List content){ w^09|k
this.page = page; WZaOw w
this.content = content; uUb[Dqn
} v|~ yIywf
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/** s
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* @return Returns the content. I3o6ym-i
*/ Oa=0d;_
publicList getContent(){ o|G.tBpKg
return content; 5!,`LM9
} w@Ut[
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/** ?g2Wu0<
* @return Returns the page. Gc}d#oo*k
*/ aloP@U/\Sn
public Page getPage(){ D^P_3
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return page; w~sr2;rp<
} <