Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 kDJ5x8Q#
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 '+NmHu:q
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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 4^VY
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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 g6$X {
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。 BclZsU=xn
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分页支持类: N\Byg jw|
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java代码: Zgo^M,g
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package com.javaeye.common.util; 0 ]U
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import java.util.List; b#R3=TQS8
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publicclass PaginationSupport { A5tY4?|
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publicfinalstaticint PAGESIZE = 30; J[;c}
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privateint pageSize = PAGESIZE; _CPe
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privateList items; Z$Ynar
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privateint totalCount; D{h1"q
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privateint[] indexes = newint[0]; 'Zf_/y
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privateint startIndex = 0; ;Aiuy{<
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public PaginationSupport(List items, int R>Fie5?
@"-<m|lM
totalCount){ 8HdmG{7.
setPageSize(PAGESIZE); Ooz+V;#Q
setTotalCount(totalCount); uh%%MhTjv
setItems(items); q"'^W<i
setStartIndex(0); C',D"
} m>$+sMZE
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public PaginationSupport(List items, int ,2DKp hh
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totalCount, int startIndex){ ?UoA'~=
setPageSize(PAGESIZE); 1?`,h6d*=
setTotalCount(totalCount); q*TH),)J
setItems(items); "0+_P{w+
setStartIndex(startIndex); @P6K`'.0
} U^?/nRZ
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public PaginationSupport(List items, int Z&@X4X"q
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totalCount, int pageSize, int startIndex){ MFaK=1
setPageSize(pageSize); ]<A|GY0q1
setTotalCount(totalCount); Z,qo
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setItems(items); QS,IM>Nr
setStartIndex(startIndex); R:x4j#(
} *Eu
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publicList getItems(){ "wmQ,=
return items; RO=[Rr!
} GptJQ=pV
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publicvoid setItems(List items){ #QQ\xj
this.items = items; QQ!%lbMK]
} 'N)&;ADx-G
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publicint getPageSize(){ z9U<Z^4z+
return pageSize; Vc$x?=
} _+N*4
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publicvoid setPageSize(int pageSize){ nM34zVy
this.pageSize = pageSize; OljUK,I]
} ;FQAL@"Yj
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publicint getTotalCount(){ 4Z"DF)+}
return totalCount; *TVr|
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} '0 GCaL*Sd
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publicvoid setTotalCount(int totalCount){ u1/4WYJeJ
if(totalCount > 0){ :h=];^/E
this.totalCount = totalCount; 2)h
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int count = totalCount / I1BVqIt1i
*L%HH@] %_
pageSize; F(^vD_G
if(totalCount % pageSize > 0) cP`f\\c
count++; o"R[#E&Yx
indexes = newint[count]; $`.7XD}
for(int i = 0; i < count; i++){ DbP!wU lqR
indexes = pageSize * mEv<r6qDT
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i; +^Eruv+F
} ?P,z^
}else{ ;RB]awE
this.totalCount = 0; )7Gm<r
} 3_~V(a
} Ovv~ymj
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publicint[] getIndexes(){ r@f8-!{s2h
return indexes; >y"W(
} q|b#=Af]g
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publicvoid setIndexes(int[] indexes){ [0El z@.C
this.indexes = indexes; 6C4c.+S
} C$SuFL(pb
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publicint getStartIndex(){ {3@f(H m
return startIndex; v{$X2z_$w
} )~v`dwKj;
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publicvoid setStartIndex(int startIndex){ K>l$Y#x}k
if(totalCount <= 0) F?\XhoJ3G
this.startIndex = 0; 4Pe%*WTX
elseif(startIndex >= totalCount) x5YW6R.<t
this.startIndex = indexes 0#<q]M?hW
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[indexes.length - 1]; " JFx
elseif(startIndex < 0) O
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this.startIndex = 0; 9cp-Rw<tI
else{ Urj8v2k
this.startIndex = indexes Xt^ldW
%%)"W
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[startIndex / pageSize]; >0DQ<@ot:
} t, #7F$t
} I'HPy.PV
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publicint getNextIndex(){ So{/V%
int nextIndex = getStartIndex() + N9tH0
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pageSize; }pdn-#
if(nextIndex >= totalCount) H<#M)8
return getStartIndex(); bGOOC?[UX
else /W1!mih
return nextIndex; <qT[
} ?1*Ka
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publicint getPreviousIndex(){ .T
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int previousIndex = getStartIndex() - =e](eA;
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pageSize; QMLz
if(previousIndex < 0) 1"YN{Ut;G
return0; n/6#rj^$
else NY
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return previousIndex; Atc9[<~WG
} <K;
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} *`Swv`
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抽象业务类 CuC1s>
java代码: p4GhT~)l:
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/** ?g^42IYG
* Created on 2005-7-12 =!)Ye:\Q
*/ O2;FaASF
package com.javaeye.common.business; _; !7:'J
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import java.io.Serializable; iGB1f*K%x
import java.util.List; *;t\!XDgp
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import org.hibernate.Criteria; J|,Uu^7`
import org.hibernate.HibernateException; V[ju7\>$Z
import org.hibernate.Session; 86Hg?!<i.
import org.hibernate.criterion.DetachedCriteria; dp#JvZb
import org.hibernate.criterion.Projections; 7f|8SB
import ?lq
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org.springframework.orm.hibernate3.HibernateCallback; 5;'(^z-bL
import VzfaUAIZl
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org.springframework.orm.hibernate3.support.HibernateDaoS 0t*e#,y
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upport; K8#MQR2@
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import com.javaeye.common.util.PaginationSupport; xfoQx_]$Im
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public abstract class AbstractManager extends scX'>\w&c
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HibernateDaoSupport { _PT5
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privateboolean cacheQueries = false; 94^)Ar~O
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privateString queryCacheRegion; aItQ(+y
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publicvoid setCacheQueries(boolean B@cC'F#G
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cacheQueries){ V=^B7a.;>
this.cacheQueries = cacheQueries; ICck 0S!
} A0hKzj
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publicvoid setQueryCacheRegion(String (P!r^87
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queryCacheRegion){ fg$#ZCi
this.queryCacheRegion = fi%)520
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queryCacheRegion; 4>^LEp
} `%QXaKO-
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publicvoid save(finalObject entity){ Hjhgu=
getHibernateTemplate().save(entity); &~mJ
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} '8J!(+
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publicvoid persist(finalObject entity){ ;~D$rT
getHibernateTemplate().save(entity); yFoPCA86y
} Hlhd6be
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publicvoid update(finalObject entity){ IiU\}<O
getHibernateTemplate().update(entity); EfX\" y
} e!W U
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publicvoid delete(finalObject entity){ Y5c,O>T5Y
getHibernateTemplate().delete(entity); R
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} mR|L'[l
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publicObject load(finalClass entity, CbGfVdw/c
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finalSerializable id){ d|#&j."
return getHibernateTemplate().load |d$4Fu(M~
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(entity, id); 1aI&jdJk
} JBhM*-t(M1
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publicObject get(finalClass entity, vtq$@#?~ b
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finalSerializable id){ |kY}G3/
return getHibernateTemplate().get clG@]<a`_
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(entity, id); Ii9[[I
} nw4I<Q
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publicList findAll(finalClass entity){ dGyrzuPJ
return getHibernateTemplate().find("from K| dI'TnW
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" + entity.getName()); ]d67 HOyK
} 1rx,qfCq
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publicList findByNamedQuery(finalString xi51,y+(5
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namedQuery){ ?g\emhG
return getHibernateTemplate y2W|,=Vd
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().findByNamedQuery(namedQuery); T;G<62`.h
} wz'=
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publicList findByNamedQuery(finalString query, Ul_5"3ze
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finalObject parameter){ TZ63=m
return getHibernateTemplate &szYa-K*
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().findByNamedQuery(query, parameter); ]]0Yh
} ^Q6?T(%$
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publicList findByNamedQuery(finalString query, He,,bq
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finalObject[] parameters){ Sn
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return getHibernateTemplate b'``0OB )
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().findByNamedQuery(query, parameters); |
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} k#bG&BF
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publicList find(finalString query){ <UF0Xc&X'
return getHibernateTemplate().find MuJP.]5>`
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(query); o$eo\X?J?
} ;4U"y8PVTh
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publicList find(finalString query, finalObject Y[l<fbh(}
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parameter){ ue^HhZ9
return getHibernateTemplate().find GE`1j'^-
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(query, parameter); 3&>0'h
} wVqp')e
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public PaginationSupport findPageByCriteria [UXN=
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(final DetachedCriteria detachedCriteria){ xP_/5N=f
return findPageByCriteria *Y?oAVkz
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); r;xy/*%Mtj
} &<x.D]FA]
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public PaginationSupport findPageByCriteria D2g/P8.<A
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(final DetachedCriteria detachedCriteria, finalint w
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startIndex){ pHuR_U5*?
return findPageByCriteria ^B0Qk:%P^N
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(detachedCriteria, PaginationSupport.PAGESIZE, }toe'6
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startIndex); ;DSH$'1i
} 7Q]c=i cg
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public PaginationSupport findPageByCriteria "w$,`M?2
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(final DetachedCriteria detachedCriteria, finalint
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pageSize, zz[fkH3
finalint startIndex){ B2oKvgw
return(PaginationSupport) ywl=@
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getHibernateTemplate().execute(new HibernateCallback(){ ^GAJ9AF@(
publicObject doInHibernate d&CpaOSu
&&m3E=K!^
(Session session)throws HibernateException { rrr_{d/
Criteria criteria = d|oO2yzWv
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detachedCriteria.getExecutableCriteria(session); ]iGeqwT
int totalCount = ;1[Z&Uv8
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((Integer) criteria.setProjection(Projections.rowCount 1cv~_jFh
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()).uniqueResult()).intValue(); r8@]|`j
criteria.setProjection g9q}D-
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(null); ^ZO! (
List items = w6Nnx5Ay
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criteria.setFirstResult(startIndex).setMaxResults n8F~!|lQ0
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(pageSize).list(); 4")`}T
PaginationSupport ps = }rI:pp^KS
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new PaginationSupport(items, totalCount, pageSize, =V]0G,,\
>>
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startIndex); pd#Sn+&rf
return ps; A
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} 5gtf`ebs/
}, true); '{UKO7
} ] re=8s6
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public List findAllByCriteria(final $GFR7YC 7
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DetachedCriteria detachedCriteria){ 7Vsp<s9bj
return(List) getHibernateTemplate <M@-|K"Eb
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().execute(new HibernateCallback(){ c%C6d97q
publicObject doInHibernate /3,Lp-kp
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(Session session)throws HibernateException { /O}<e TR
Criteria criteria = UMR ?q0J
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detachedCriteria.getExecutableCriteria(session); 8Rwk
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return criteria.list(); u*G<?
} /7 Tm2Vj8
}, true); PQkw)D<n]_
} ve
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public int getCountByCriteria(final s:}? rSI
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DetachedCriteria detachedCriteria){ }I&.xzJ
Integer count = (Integer) ZrTB%
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getHibernateTemplate().execute(new HibernateCallback(){ = 'NV3by
publicObject doInHibernate hr}f5Z)^v
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(Session session)throws HibernateException { _ \6v@
Criteria criteria = &
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detachedCriteria.getExecutableCriteria(session); &bW,N
return uqC#h,~
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criteria.setProjection(Projections.rowCount yx5e
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()).uniqueResult(); E7fQ9]
} I_<XL<
}, true); ixu*@{<Z(
return count.intValue(); #y83tNev
} G kjfDY:
} 172 G
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用户在web层构造查询条件detachedCriteria,和可选的 dT|f<E/P
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 P35DVK S
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PaginationSupport的实例ps。 T;/GHC`{Y
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ps.getItems()得到已分页好的结果集 U =.PL\
ps.getIndexes()得到分页索引的数组 G;l7,1;MU:
ps.getTotalCount()得到总结果数 v_!6S|
ps.getStartIndex()当前分页索引 %+(AKZu:
ps.getNextIndex()下一页索引 t]LiFpy2IC
ps.getPreviousIndex()上一页索引 a:)FWdp?9
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 @f-X/q]P
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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 `I5^zi8
/ I`TN5~
一下代码重构了。 qH}8TC
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我把原本我的做法也提供出来供大家讨论吧: 1ML L
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首先,为了实现分页查询,我封装了一个Page类: +
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java代码: tK%ie\
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/*Created on 2005-4-14*/ !g|O.mt
package org.flyware.util.page;
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d05xn7%!{
/** ,Xn2xOP
* @author Joa }%_|k^t
* Zhq_ pus"a
*/ $D^\[^S
publicclass Page {
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/** imply if the page has previous page */ n[3z_QI
privateboolean hasPrePage; Qg*\aa94
0\dmp'j]
/** imply if the page has next page */ .EKlw##
privateboolean hasNextPage; m-AF&( ;K
M~:_^B
/** the number of every page */ +Q5O$8i
privateint everyPage; *-T.xo
cE]z Tu?!
/** the total page number */ =}`d
privateint totalPage; E3uu vQ#|
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/** the number of current page */ 2Vx4"fHP#N
privateint currentPage; y(COB6r
Pd91<L
/** the begin index of the records by the current UM7@c7B?
{[H_Vl@
query */ C*Vm}|)
privateint beginIndex; 9{u8fDm!
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/** The default constructor */ 3( BL
public Page(){ F9r.DG$}
&6x(%o|
} '}Fe&%
yfG;OnkZ
/** construct the page by everyPage 46:<[0Psl/
* @param everyPage o:d7IL
* */ ppAbG,7
public Page(int everyPage){ 0?7yM:!l
this.everyPage = everyPage; PIri|ZS
} C >*z^6Gz
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/** The whole constructor */ .vu7$~7
public Page(boolean hasPrePage, boolean hasNextPage, \o>-L\`O
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int everyPage, int totalPage, 2 2v"?*
int currentPage, int beginIndex){ V! Wy[u
this.hasPrePage = hasPrePage;
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this.hasNextPage = hasNextPage; $BwWQ?lp
this.everyPage = everyPage; hi8q?4jE
this.totalPage = totalPage; c!Hz'W
this.currentPage = currentPage; Bz]tKJ
this.beginIndex = beginIndex; )4g_S?l=
} t<!m4Yd|#
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/** R]"Zv'M(AM
* @return qed_ PsI
* Returns the beginIndex. 7
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*/ HMq}){=S
publicint getBeginIndex(){ [DaAvN^0A
return beginIndex; Q0J1"*P0
} kF|$oBQ
PL:(Se%
/** z9o]);dZ
* @param beginIndex >dAl *T
* The beginIndex to set. IK -vcG
*/ {<-s&%/r
publicvoid setBeginIndex(int beginIndex){ :\;9y3
this.beginIndex = beginIndex; &f.5:u%{b
} F-;J N
O/~T+T%
/** DsdM:u*s
* @return fQoAdw
* Returns the currentPage. V;SfW2`)
*/ l#0zHBc
publicint getCurrentPage(){ v`S5[{6
return currentPage; i/X3k&
} k\OZ'dS
xg p)G!
/** 4&*lpl*N
* @param currentPage ~>:JwTy
* The currentPage to set. 3!P^?[p3
*/ 7F"ljkN1S
publicvoid setCurrentPage(int currentPage){ RZz?_1'
this.currentPage = currentPage; 4phCn5
} @fd<
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/** / 4Q=%n
* @return A[P7hMn
* Returns the everyPage. wX] _Abk
*/ *"^X)Y{c+l
publicint getEveryPage(){ uI,*&bP
return everyPage; =]@Bc
7@
} Zr}>>aIJ]k
amsl>wc!
/** 11PL1zzH
* @param everyPage Vz mlKVE
* The everyPage to set. ]yOM
*/ 2^XmtT
publicvoid setEveryPage(int everyPage){ NZGO8u
this.everyPage = everyPage; h%j4(v}r{C
} BFNO yv
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/** dz#"9i5b
* @return oCo~,~kTR
* Returns the hasNextPage. .\bJ,of9
*/ dOD(<
publicboolean getHasNextPage(){ lr&2,p<
return hasNextPage; 4W>DW`{
} LsR<r1KDJ
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/** H [+'>Id:
* @param hasNextPage @;EQ{d
* The hasNextPage to set. ;8H&FsR
*/ C?. ;3 h
publicvoid setHasNextPage(boolean hasNextPage){ =o@}~G&HA
this.hasNextPage = hasNextPage; wo9R:kQ
} 3r%v@8)!b
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/** n[/D>Pi
* @return Yte*$cJ=
* Returns the hasPrePage. (
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*/ t(}Y /'
publicboolean getHasPrePage(){ 9ERdjS
return hasPrePage; 5T/+pC$e=
} XzAXcxC6G
3\2&?VAjR
/** >(:3H+
* @param hasPrePage 55v=Ij?M
* The hasPrePage to set. TrDTay
*/ J#d,?
publicvoid setHasPrePage(boolean hasPrePage){ .UxkTads
this.hasPrePage = hasPrePage; y1`%3\
} T3b0"o27
}5E H67
/** 9Zx| L/\
* @return Returns the totalPage. A7QT4h&6
* F]OWqUV
*/ `@Z$+
publicint getTotalPage(){ }r04*P(
return totalPage; R1*&rjB
} ~&/Nl_#
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/** =YM
* @param totalPage ,>6mc=p
* The totalPage to set. UXSwd#I&
*/ 8?~>FLWTXZ
publicvoid setTotalPage(int totalPage){ SP0ueAa}
this.totalPage = totalPage; ^C,rN;mX'
} FUI/ A>
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} C4E* q3[Y
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 uToi4]w"y
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个PageUtil,负责对Page对象进行构造: 9Eh*r@>
java代码: r 8N<<^
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/*Created on 2005-4-14*/ 1%@i4
package org.flyware.util.page; ,*$Y[UT
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import org.apache.commons.logging.Log; o &b\bK%E
import org.apache.commons.logging.LogFactory; '<"%>-^Gn
i[/1AI
/** *<9M|H~
* @author Joa SOD3MsAK
* 1\TkI=N3
*/ B
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publicclass PageUtil { c3fd6Je5
x}C$/ 7^
privatestaticfinal Log logger = LogFactory.getLog (>Sy,
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(PageUtil.class); JpQV7}$
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Z
/** 8yr-X!eF
* Use the origin page to create a new page Mt4`~`6
* @param page wC1)\ld
* @param totalRecords Qz"@<qgQy
* @return zPvTRW~H\
*/
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publicstatic Page createPage(Page page, int 0s4]eEXH
b^Do[o}5
totalRecords){ DUf. F
return createPage(page.getEveryPage(), %z1hXh#+
|$T?P*pI.
page.getCurrentPage(), totalRecords); f]+.
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} LNgFk%EH
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/** *@
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* the basic page utils not including exception Ob'[W;p)[w
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handler ?.I1"C,#VJ
* @param everyPage Y
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* @param currentPage \a:-xwUu<
* @param totalRecords u_=>r_J[b
* @return page t-FrF </0
*/ \n0Gr\:
publicstatic Page createPage(int everyPage, int ZYl*-i&~?
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currentPage, int totalRecords){ uCFpH5>
everyPage = getEveryPage(everyPage); 'kCr1t
currentPage = getCurrentPage(currentPage); *xKY>E+
int beginIndex = getBeginIndex(everyPage, R*"zLJP
&'5j!
currentPage); }e1]Ib!
int totalPage = getTotalPage(everyPage, Oi!uJofW
^O5PcV 3Eg
totalRecords); EU7mP
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boolean hasNextPage = hasNextPage(currentPage, w3Qil[rg
n\scOM)3
totalPage); XQ k,xQ
boolean hasPrePage = hasPrePage(currentPage); B?XqH_=0L
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returnnew Page(hasPrePage, hasNextPage, G{s
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everyPage, totalPage, _'r&'s;<z
currentPage, xirZ.wj W
M-f; ,>
beginIndex); x8rp Z
} }!vJ+
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privatestaticint getEveryPage(int everyPage){ _`]YWvh
return everyPage == 0 ? 10 : everyPage; /vPcg
} sr$JFMTO11
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privatestaticint getCurrentPage(int currentPage){ ADZU?7)
return currentPage == 0 ? 1 : currentPage; w#$Q?u ,G
} =
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privatestaticint getBeginIndex(int everyPage, int SQBe}FlktK
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currentPage){ oGZ%w4T
return(currentPage - 1) * everyPage; lGN{1djT
} [)p>pA2GZj
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privatestaticint getTotalPage(int everyPage, int }W"/h)q
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totalRecords){ %,5_]bGvb
int totalPage = 0; *p%=u>?&
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if(totalRecords % everyPage == 0) pj'[
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totalPage = totalRecords / everyPage; v+`gQXJ"G
else .37Jrh0Iv
totalPage = totalRecords / everyPage + 1 ; zC\L-i>G
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return totalPage; F| O
} I.}E#f/A'
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privatestaticboolean hasPrePage(int currentPage){ LZ*ZXFIg
return currentPage == 1 ? false : true; 64-;| k4F
} Xkb\fR6<K
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privatestaticboolean hasNextPage(int currentPage, ZC:7N{a
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int totalPage){ kC-OZ VoO
return currentPage == totalPage || totalPage == >a2i%j/T
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0 ? false : true; 5"9!kZ(<
} [E|%
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} t5WW3$Nf
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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。 \B~}s }
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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 6` @4i'.
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做法如下: r5g:#mF"
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 #Rcb
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的信息,和一个结果集List: 5ki<1{aVtZ
java代码: KI{B<S3*Z
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/*Created on 2005-6-13*/ u3ns-e
package com.adt.bo; o79EDPX
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import java.util.List; -9z!fCu3
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import org.flyware.util.page.Page; /KH,11)yc
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/** '9d]
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* @author Joa Sr?2~R0&
*/ {:0TiOP5x
publicclass Result { NvqIYW
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private Page page; a8laPN
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private List content; ;HbAk`\1A
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/** @is !VzE
* The default constructor [=q&5'FY0
*/ ^J-\s_)"
public Result(){ NhYce>
super(); B78e*nNS#2
} _)?59
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/** MYVgi{
* The constructor using fields )tW0iFY
* =9AX\2w*H;
* @param page soXIPf
* @param content gkw/Rd1oG
*/ hYS}PE
public Result(Page page, List content){ (B:+md\Q
this.page = page; ^>ICycJ
this.content = content; yTb#V"eR
} JcDcYB
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/** Yy3g7!K5E
* @return Returns the content. osdl dS
*/ :7[20n}w
publicList getContent(){ q71~Y:7f
return content; i~0x/wSl_
} 5.3=2/
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/** H%z9VJ*!0
* @return Returns the page. waI:w,
*/ 'Wz`P#/
public Page getPage(){ 6=o'.03\f
return page; zt|DHVy
} g ONybz6]
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/** |`,AAa
* @param content .ZK^kcyA
* The content to set. /\0g)B;]
*/ }lP'bu
public void setContent(List content){ he\ pW5p
this.content = content; LX2Re
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} o3OtG#g2
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/** _aj,tz
* @param page yT<