Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 i&{%}==7
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 XSGBC:U)l
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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 V>D}z8w7
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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 V[n,fEPBr
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分页支持类: zbgGK7
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java代码: f~7V< v
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package com.javaeye.common.util; Hbn78,~.
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import java.util.List; i! gS]?*DH
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publicclass PaginationSupport { XlnSh<e
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publicfinalstaticint PAGESIZE = 30; BGHZL~
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privateint pageSize = PAGESIZE; nLCaik_,m
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privateList items; q@tym5
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privateint totalCount; =3!o_
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privateint[] indexes = newint[0]; |(AFU3~
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privateint startIndex = 0; VJ?>o
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public PaginationSupport(List items, int T#wG]DH;
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totalCount){ vPc*x5w-
setPageSize(PAGESIZE); $HtGB]
setTotalCount(totalCount); "YWZ&_n**
setItems(items); Ay PtbrO
setStartIndex(0); @DF7j|]tV
} ZCViZWo
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public PaginationSupport(List items, int @BG].UJo
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totalCount, int startIndex){ dFA1nn6{
setPageSize(PAGESIZE); uB#U(
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setTotalCount(totalCount); [ D.%v~j
setItems(items); C!ch
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setStartIndex(startIndex); k/sfak{Q
} LNyrIk/1
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public PaginationSupport(List items, int %M))Ak4~a
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totalCount, int pageSize, int startIndex){ >239SyC-,
setPageSize(pageSize); boHbiE
setTotalCount(totalCount); fx>U2
setItems(items); )W InPW
setStartIndex(startIndex); x/wgD'?
} lfre-pS+
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publicList getItems(){ *ra>Kl0
return items; Ga-cto1Y
} cpALs1j:
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j
publicvoid setItems(List items){ \P")Eh =d
this.items = items; =,h'}(z_
} [`s0 L#
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publicint getPageSize(){ a(=lQ(v/?
return pageSize; @0]WMI9B"B
} _>rM[\|X
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publicvoid setPageSize(int pageSize){ 9[;da
this.pageSize = pageSize; }WaZ+Mdg\
} 9t6c*|60#n
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publicint getTotalCount(){ k!}(a0h
return totalCount; 8A.7q
} M=lU`Sm
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publicvoid setTotalCount(int totalCount){ &$
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if(totalCount > 0){ <U1T_fiBoc
this.totalCount = totalCount; 1dw{:X=j
int count = totalCount / mC$y*G
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pageSize; p)ig~kk`
if(totalCount % pageSize > 0) q6w)zTpJGJ
count++; ~J&-~<%P}
indexes = newint[count]; E #B$.K
for(int i = 0; i < count; i++){ J-<_e??
indexes = pageSize * Tjq1[Wq
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i; n6+h;+8;]
} T!ZjgCY}
}else{ JJ%@m;~
this.totalCount = 0; CbC[aVA=
} 1[8^JVC>6
} d}':7Np
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publicint[] getIndexes(){ F8"J<VJ7
return indexes; Q?1J<(oq9
} 1*2ycfa
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publicvoid setIndexes(int[] indexes){ *1{A'`.=\
this.indexes = indexes; v/9ZTd
} GWWg3z.o"W
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publicint getStartIndex(){ :PW"7|c!
return startIndex; $!MP0f\q
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} 8=TC 3]
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publicvoid setStartIndex(int startIndex){ /51$o\4S
if(totalCount <= 0) OKlR`Vaty
this.startIndex = 0; D
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elseif(startIndex >= totalCount) dk
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this.startIndex = indexes A,~KrRd
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[indexes.length - 1]; boGdZ2$h4
elseif(startIndex < 0) |1(x2x%}D^
this.startIndex = 0; 6XF Ufi+
else{ )9_W"'V
this.startIndex = indexes I9qFXvqL
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[startIndex / pageSize]; 3*~`z9-z
} SsTBjIX
} v_EgY2l(
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publicint getNextIndex(){ @Kz,TP!%A
int nextIndex = getStartIndex() + ">CRFee0
; F'IS/ttX
pageSize; gv>DOez/
if(nextIndex >= totalCount) jVd`J
return getStartIndex(); F:T(-,
else el*|@#k}
return nextIndex; Tp?IK_
} Mf#@8"l
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publicint getPreviousIndex(){ oo\^}jb
int previousIndex = getStartIndex() - %%}l[W
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pageSize; BInSS*L
if(previousIndex < 0) Lv['/!DJ|
return0; dN3^PK
else 1C{0 R.
return previousIndex; C/Tk`C&
} N=C t3
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} %xCL&}bY
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抽象业务类 PiM(QR
java代码: i@nRZ$ K
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/** N^$q;%
* Created on 2005-7-12 bWp:!w#K
*/ W,6q1
package com.javaeye.common.business; ^3$U[u%q/{
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import java.io.Serializable; f&4+-w.:V|
import java.util.List; f}(4v1T
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import org.hibernate.Criteria; m_oUl(pk
import org.hibernate.HibernateException; _Sfu8k>):
import org.hibernate.Session; /C Xg$%\
import org.hibernate.criterion.DetachedCriteria; n'^`;-
import org.hibernate.criterion.Projections; |.$B,cEd
import F$tzsz,9n
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org.springframework.orm.hibernate3.HibernateCallback; H!]&"V77
import -%MXt
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org.springframework.orm.hibernate3.support.HibernateDaoS r4/b~n+*
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upport; "[~yu*
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import com.javaeye.common.util.PaginationSupport; %<nGm\
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public abstract class AbstractManager extends &?bsBqpN
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HibernateDaoSupport { #rX^)2
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privateboolean cacheQueries = false; pP":,8Q{
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privateString queryCacheRegion; KJoa^e;~
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publicvoid setCacheQueries(boolean 'uL$j=vB
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cacheQueries){ W`9{RZ'
this.cacheQueries = cacheQueries; C;HEvq7
} $7Hwu^c(
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publicvoid setQueryCacheRegion(String ##Pzc~xSn
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queryCacheRegion){ jy.L/s
this.queryCacheRegion = 'XKfKv >;
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queryCacheRegion; _0rt.NRD
} qzxWv5UH
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publicvoid save(finalObject entity){ k8}fKVU;
getHibernateTemplate().save(entity); ASoBa&vX
} p1niS:}j
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publicvoid persist(finalObject entity){ j:1N&7<FU
getHibernateTemplate().save(entity); 02;'"EmP$
} Tdh.U{Nz
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publicvoid update(finalObject entity){ 33lh~+C
getHibernateTemplate().update(entity); ,^c-}`!K
} Uz_ob9l<#H
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publicvoid delete(finalObject entity){ qbq2Bi'a
getHibernateTemplate().delete(entity); HLDv{G'7
} N*Q*>q
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publicObject load(finalClass entity, npkT>dB+
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finalSerializable id){ k8stXW-w
return getHibernateTemplate().load hk5!$#^
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(entity, id); n
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} Vbp@n
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publicObject get(finalClass entity, n%36a(]
t
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finalSerializable id){ "6%{#TZ
return getHibernateTemplate().get wS|k3^OV%
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(entity, id); l^bak]9 1
} Pl'lmUR
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publicList findAll(finalClass entity){ o<48' >[
return getHibernateTemplate().find("from J#wf`VR%
,|$1(z*a{c
" + entity.getName()); 9s5s;ntz"
} dRzeHuF92
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publicList findByNamedQuery(finalString \PN*gDmX
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namedQuery){ /V+7:WDj
return getHibernateTemplate k}g4?
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().findByNamedQuery(namedQuery); \bF<f02P
} R$u1\r1I
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publicList findByNamedQuery(finalString query, uYlyU~M:D
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finalObject parameter){
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return getHibernateTemplate 3<)][<Ud
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().findByNamedQuery(query, parameter); Fg
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} RRyD<7s1
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publicList findByNamedQuery(finalString query, VgbT/v
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finalObject[] parameters){ oc-&}R4=
return getHibernateTemplate e@O]c"
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().findByNamedQuery(query, parameters); N\]-/$ z
} 9UteD@*
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publicList find(finalString query){ R!"`Po
return getHibernateTemplate().find I+Yq",{%
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(query); L^CB#5uG
} Y<Ae_yLa
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publicList find(finalString query, finalObject \ 6taC
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parameter){ ODRy
return getHibernateTemplate().find S/eplz;
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(query, parameter); H0B=X l[
} dhP")@3K;p
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public PaginationSupport findPageByCriteria aEa.g.SZ
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(final DetachedCriteria detachedCriteria){ =s.0 f:(
return findPageByCriteria #$U/*~m $
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 0RSzDgX
} ,qB@agjvo<
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public PaginationSupport findPageByCriteria 2V; Dn$q
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(final DetachedCriteria detachedCriteria, finalint [q0^Bn}h
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startIndex){ hDg"?{
return findPageByCriteria `DGI|3
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(detachedCriteria, PaginationSupport.PAGESIZE, /i_FA]Go
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startIndex); XLYGhM
} ]NW_oRH
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public PaginationSupport findPageByCriteria #_3ZF"[zq
/={N^8^=x
(final DetachedCriteria detachedCriteria, finalint 7z\#"~(.
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pageSize, }[c.OJ:
finalint startIndex){ ;2?fz@KZ
return(PaginationSupport) g^po$%I '
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getHibernateTemplate().execute(new HibernateCallback(){ fV6ddh
publicObject doInHibernate 'F/uD1;
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(Session session)throws HibernateException { p,(W?.ZDN?
Criteria criteria = c*R\fQd
S5H}
detachedCriteria.getExecutableCriteria(session); h~._R6y
int totalCount = I;?PDhDb
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((Integer) criteria.setProjection(Projections.rowCount hVFZQJ?cv
;1_3E2E$
()).uniqueResult()).intValue(); Fwvc+ a
criteria.setProjection Tk 'Pv
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(null); Bz%wV-
List items = m9c`"!
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criteria.setFirstResult(startIndex).setMaxResults ^rY18?XC+:
OYmutq
(pageSize).list(); ]70ZerQ~L
PaginationSupport ps = ^,f^YL;
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new PaginationSupport(items, totalCount, pageSize, v/v PU
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startIndex); V`c,U7[/
return ps; Ut/%+r"s
} .>}Z3jUrf
}, true); 8y[Rwa
} #l9sQ-1Q
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public List findAllByCriteria(final `q | )_
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DetachedCriteria detachedCriteria){ 4OAR ["f
return(List) getHibernateTemplate Pv)^L
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().execute(new HibernateCallback(){ BT3yrq9
publicObject doInHibernate "|,KXv')
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(Session session)throws HibernateException { /74h+.amg
Criteria criteria = ru1^.(W2
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detachedCriteria.getExecutableCriteria(session); v7hw% 9(=
return criteria.list(); m9DTz$S.
} VT~%);.#
}, true); dd
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} k#/cdK!K
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public int getCountByCriteria(final ])?h~
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DetachedCriteria detachedCriteria){ GlC (uhCpV
Integer count = (Integer) 1IT(5Mleb
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getHibernateTemplate().execute(new HibernateCallback(){ *p\fb7Pu_3
publicObject doInHibernate !4Sd ^"
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(Session session)throws HibernateException { i]@k'2N
Criteria criteria = LZ&I<ID`-
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detachedCriteria.getExecutableCriteria(session); QOPh3+.5
return qM2m !
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criteria.setProjection(Projections.rowCount }1CvbB%,A
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()).uniqueResult(); !\Cu J5U
} 0pH$MkQ
}, true); utn,`v
return count.intValue(); 3rJ LLYR
} MJH>rsTQ
} ^Q+z^zlC
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用户在web层构造查询条件detachedCriteria,和可选的 W+4Bx=Mj
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 V pY,@qh
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PaginationSupport的实例ps。 XgeUS;qtta
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ps.getItems()得到已分页好的结果集 `fG<iBD
ps.getIndexes()得到分页索引的数组 :2wT)w z
ps.getTotalCount()得到总结果数 *1:kIi7_
ps.getStartIndex()当前分页索引 7;r3Bxa
Q
ps.getNextIndex()下一页索引 DFRgn
ps.getPreviousIndex()上一页索引 id`RscV]
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 &wu1Zz[qcz
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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 ^\\9B-MvY
,KPrUM}
一下代码重构了。 Yg 2P(
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我把原本我的做法也提供出来供大家讨论吧: *;F<Q!i&v
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首先,为了实现分页查询,我封装了一个Page类: GyFA1%(o
java代码: \~U:k4
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/*Created on 2005-4-14*/ MFWkJbZV
package org.flyware.util.page; y;P%=MP
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/** #P!M"_z
* @author Joa xsS;<uCD
* a`eb9o#
*/ Li 9$N"2
publicclass Page { Tn\{*A
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/** imply if the page has previous page */ ?UeV5<TewS
privateboolean hasPrePage; i`iR7UmHeR
j*GS')Cm
/** imply if the page has next page */ |}X[Yg=FG
privateboolean hasNextPage; ;.R)
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/** the number of every page */ /{I-gjovy
privateint everyPage; L(1} PZ
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/** the total page number */ 45jImCm
privateint totalPage; :n%&
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/** the number of current page */ \E05qk_;K
privateint currentPage; ]<Q&
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/** the begin index of the records by the current #nZPnc:
M}=>~TA@
query */ !g#y$
privateint beginIndex; KhL%ov
l=$?#^^ /
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/** The default constructor */ ?@6Zv$vZ
public Page(){ xv%]g=Q
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} =&FaMR2
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/** construct the page by everyPage MvaX>n!o
* @param everyPage :6o|6MC!
* */ :$P1ps3B
public Page(int everyPage){ cXYE!(
this.everyPage = everyPage; 6C
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} <;1M!.)5
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/** The whole constructor */ t2m7Yh5B
public Page(boolean hasPrePage, boolean hasNextPage, K<pZ*l
J*Cf1 D5!
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int everyPage, int totalPage, IaO&f<^#o
int currentPage, int beginIndex){ BV}sN{
this.hasPrePage = hasPrePage; TWfkr
this.hasNextPage = hasNextPage; Ya!PV&"Z
this.everyPage = everyPage; 'tX}6wurf
this.totalPage = totalPage; mSk";UCn
this.currentPage = currentPage; 8-@HzS%
this.beginIndex = beginIndex; QDKY7"H
} 4<f^/!9w
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/** Lnq CHe
* @return )FfS7 C\.
* Returns the beginIndex.
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*/ W"A3$/nq^
publicint getBeginIndex(){ 6X4r2Vq
return beginIndex; BD]o+96qP
} 6k{gI.SG
Pw6%,?lQ
/** 38:5g_
* @param beginIndex {7_C|z:'p&
* The beginIndex to set. &78lep
*/ -uhVw_qq#
publicvoid setBeginIndex(int beginIndex){ ^7=h%{>=
this.beginIndex = beginIndex; >Dz8+y
} +NeoGnj
,F "P/`i'
/** Wo,93]
* @return 0 ;4 YU%u
* Returns the currentPage. nu2m5RYx
*/ >q ,Z*s>?
publicint getCurrentPage(){ "x
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return currentPage; *,=8x\Shp
} 9j5-/
3[ xHY@c
/** /R>YDout}
* @param currentPage BE54L+$p
* The currentPage to set. ' hdLQ\J
*/ Ua~8DdW
publicvoid setCurrentPage(int currentPage){ 7d+0'3%
this.currentPage = currentPage; /1Ss |.
} v0T?c53?
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/** t{`krs``
* @return / neY2D6
* Returns the everyPage. 6
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*/ ~Qf\DTM&
publicint getEveryPage(){ E[BM0.#bZ
return everyPage; Q~KzcB<
} }
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/** iI &z5Q2
* @param everyPage XdnpL$0
* The everyPage to set. 3/]~#y%2
*/ _p^Wc.[~M
publicvoid setEveryPage(int everyPage){ 8m[o*E.4F
this.everyPage = everyPage; ]]y,FQ,r
} _G2)=yj]
xP27j_*m>
/** $-s8tc(
* @return /wkrfYRs
* Returns the hasNextPage. MIN}5kc<
*/ O:imX>|u
publicboolean getHasNextPage(){ a^Q
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return hasNextPage; sI{?4k
} :%+9y @%
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/** gN*b~&G
* @param hasNextPage {xICR ~,*
* The hasNextPage to set. l j+p}dt
*/ k"m+i
publicvoid setHasNextPage(boolean hasNextPage){ @3~Wukc
this.hasNextPage = hasNextPage; 6^2='y~e
} %:sP #BQM
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/** bXqTc2>=
* @return 7`^=Ie%(K
* Returns the hasPrePage. KUUZN
*/ 8>xd
publicboolean getHasPrePage(){ Tl+PRR6D*
return hasPrePage; +6^hp-G7
} 0<^Qj.(9
Vo|[Z)MO`
/** ~ftR:F|9
* @param hasPrePage ]3Jb$Q@
* The hasPrePage to set. 7loWqZ
*/ V6k Dyl(
publicvoid setHasPrePage(boolean hasPrePage){ ID<[=es6
this.hasPrePage = hasPrePage; KTeR;6oZn"
} k`s_31<
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/** Z>dvth
* @return Returns the totalPage. r"t,/@`n
* bw!*=<
*/ `(6cRT`Wp
publicint getTotalPage(){ h8;H<Y;yQ
return totalPage; 7|o}m}yVx
} %zhSSB=BJ
ih|&q
/** ,vBB". LY'
* @param totalPage zz8NBO
* The totalPage to set. z(#dL>d$'
*/ :8N{;aui
publicvoid setTotalPage(int totalPage){ IYr}%:P)
this.totalPage = totalPage; s{42_O?,c
} nB/`~_9
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} i@ 86Ez
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k7(lwEgNG
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 Qv)DSl
+
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个PageUtil,负责对Page对象进行构造: ?=HoU3
java代码: J0o,ZH9
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/*Created on 2005-4-14*/ zy|h1.gd
package org.flyware.util.page; qa4j>;
aY DM)b}
import org.apache.commons.logging.Log; =4OV
}z=I
import org.apache.commons.logging.LogFactory; }C$D-fH8sW
nj-LG!"a
/** 1KjzKFnb
* @author Joa Q@"!uB.e
* zQ(`pld
*/ lg{M\
+
publicclass PageUtil { u)%/df qzZ
L D%SLJ:
privatestaticfinal Log logger = LogFactory.getLog Pj5:=d8z(
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(PageUtil.class); `trcYmR=k
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/** Hr \vu`p$
* Use the origin page to create a new page :!FGvR6
* @param page w8#ji 1gX
* @param totalRecords i8#:y`ai
* @return n1b^o~agwC
*/ Ql,WKoj*
publicstatic Page createPage(Page page, int <@y(ikp>
`X B$t?xi
totalRecords){ /4upw`35]
return createPage(page.getEveryPage(), }|nEbM]#
Jn9{@??
page.getCurrentPage(), totalRecords); 6.a|w}C`
} z+^9)wg9
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/** r&~]6
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* the basic page utils not including exception <)"2rxX&5
*z dUCX
handler n-1
* @param everyPage P!{J28dj
* @param currentPage |\)Y,~;P
* @param totalRecords u]]mbER*t#
* @return page u_b6u@r7
*/ n;>r
publicstatic Page createPage(int everyPage, int FS*J8)
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currentPage, int totalRecords){ F3x*dq2
everyPage = getEveryPage(everyPage); cb/$P!j7
currentPage = getCurrentPage(currentPage); qV-1aaA
int beginIndex = getBeginIndex(everyPage, uX6rCokr
&
sXMB
currentPage); sXY{g0%
int totalPage = getTotalPage(everyPage, o?aF
wBEBj7(y
totalRecords); 4Vd[cRh2
boolean hasNextPage = hasNextPage(currentPage, t&IWKu#
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totalPage); Dj3,SJ*x
boolean hasPrePage = hasPrePage(currentPage); nk;+L
j|b$b,rF\
returnnew Page(hasPrePage, hasNextPage, \)2'+R
everyPage, totalPage, Z}3;Ych
currentPage, GY"c1KE$
:J+ANIRI
beginIndex); LCb0Kq}*/(
} }s8xr>
R?J8#JPXD
privatestaticint getEveryPage(int everyPage){ {@PZlQg
return everyPage == 0 ? 10 : everyPage; Ij9=J1c4
} sGa "
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privatestaticint getCurrentPage(int currentPage){ yP34h*0B
return currentPage == 0 ? 1 : currentPage; v7@*dg
} %Siw>
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privatestaticint getBeginIndex(int everyPage, int OK
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currentPage){ }$* z:E
return(currentPage - 1) * everyPage; Q_*.1L
} &0{&4,
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privatestaticint getTotalPage(int everyPage, int Hdjp^O!
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totalRecords){ -tp3qi
int totalPage = 0; T7 (d
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if(totalRecords % everyPage == 0) r/QI-Cf&
totalPage = totalRecords / everyPage; I}awembw g
else v(,YqT>q@U
totalPage = totalRecords / everyPage + 1 ; {RD9j1
f3<2531/}
return totalPage; vJ;0%;eu[!
} }hXmK.['
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privatestaticboolean hasPrePage(int currentPage){ VY@`)
return currentPage == 1 ? false : true; m=w #l>!
} 'a~F'FN$
w!}kcn<
privatestaticboolean hasNextPage(int currentPage, hzh3p[
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int totalPage){ &C#?&AQ
return currentPage == totalPage || totalPage == C @P$RVS
-y/Y%]%0
0 ? false : true; T6\d]
} w~n+hhMF
p#>,{
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} H<qz
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)?(_vrc<
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 ,5x9o"N!
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1
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 _gpf9ad
v}@Uc-(
做法如下: HYNp vK
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ~SwGZ
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的信息,和一个结果集List: xk^`4;
java代码: /8/N
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/*Created on 2005-6-13*/ 0Q]{r )
package com.adt.bo; 'Xasd3*Py
t;y@;?~
import java.util.List; >Hd!o"I
u!McPM8Yk
import org.flyware.util.page.Page; <JW%h :\t
7&Ie3[Rm_3
/** -r[O_[g w
* @author Joa :GM3n$
*/ $wk(4W8E
publicclass Result { R l)g[s
Y*S(uqM
private Page page; :S+Bu*OyH
0.B'Bvn=s2
private List content; m4R:KjN*
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/** c7R6.T
* The default constructor !]&+g'aC3
*/ ] B>.}
public Result(){ ~hT(uxU/
super(); BD mF+
} P[H 4Yp
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/** YIHGXi<"n
* The constructor using fields bq{eu#rQJ
* X$_z"t
* @param page 0 R>!jw
* @param content O#)YbaE
*/ .gCun_td#
public Result(Page page, List content){ hh-sm8
this.page = page; 'Ojxzz*tT
this.content = content; r$,Xv+}
} Ubh)}G,Mg
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/** fD2 N}
* @return Returns the content. Na+3aM%%
*/ Qgq VbJP"
publicList getContent(){ |sAl k,8s
return content; pwNF\ ={
} Z5"5Ge-M
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/** RZ?abE8
* @return Returns the page. =V:Al
*/ <
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public Page getPage(){ ?p>m;Aq
return page; "l B%"}
} uFfk!
N \woFrG
/** I@(3~ Ab
* @param content xqv&^,ic
* The content to set. #eKH'fE
*/ "?'9\<>
public void setContent(List content){ M|UCV_omN
this.content = content; :{aiw?1
} +O7GgySx
HzAw
rC
/** _DYe<f.
* @param page Pt/F$A{Cj
* The page to set. b\UE+\a&
*/ )vGxF}I3
publicvoid setPage(Page page){ O*>`md?MH
this.page = page; ~8)l/I=`);
} I-W,C&J>
} D*g
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:bqUA(k
HHT8_c'CC#
,9$| "e&
2. 编写业务逻辑接口,并实现它(UserManager, ?',GR aD
!fJy7Y
UserManagerImpl) , Q )
java代码: GGsAisF"N
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4G j
/*Created on 2005-7-15*/ Fh}GJE
package com.adt.service; !_-Uwg
H@sM$8
import net.sf.hibernate.HibernateException; MwaRwk;
FW3uq^
import org.flyware.util.page.Page; D=M'g}l
(bD#PQXzm
import com.adt.bo.Result; ?BU?c:"f
oKPG0iM:
/** @u:q#b
* @author Joa &pHXSU
*/ 8(}cbW
publicinterface UserManager { b .cBg.a
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public Result listUser(Page page)throws P}he}k&IR
C-&s$5MzGb
HibernateException; \cHFV
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} D&D-