Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 w]nt_xj
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 RN|Bk
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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 7r^Cs#b+I
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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 IaQm)"Z
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分页支持类: L>mM6$l
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java代码: d3
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package com.javaeye.common.util; ,|A6l?iV
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import java.util.List; }EYmz/nN
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publicclass PaginationSupport { ITg:OOQ
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publicfinalstaticint PAGESIZE = 30; ~(-1mB,
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privateint pageSize = PAGESIZE; GyMN;|
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privateList items; i /I
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privateint totalCount; Lq
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privateint[] indexes = newint[0]; }h1LH4
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privateint startIndex = 0; VcXr!4M
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public PaginationSupport(List items, int oV;sd5'LG
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totalCount){ \At~94
setPageSize(PAGESIZE); .ahY 1CO
setTotalCount(totalCount); $y,KDR7^
setItems(items); QH4m7M@ni
setStartIndex(0); #pgD-0_
} 4M> pHz4
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public PaginationSupport(List items, int 1LSJy*yY
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totalCount, int startIndex){ (gPB@hAv
setPageSize(PAGESIZE); B~k{f}
setTotalCount(totalCount); XR9kxTuk
setItems(items); )B+o
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setStartIndex(startIndex); ZMZWO$"K1
} r7>FH!=:
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public PaginationSupport(List items, int DBHHJD/q
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totalCount, int pageSize, int startIndex){ AzF*4x
setPageSize(pageSize); 74:( -vS
setTotalCount(totalCount); Te~jYkCd
setItems(items); |f$ws R`&
setStartIndex(startIndex); N\&VJc
} 2;*G!rE&*`
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publicList getItems(){ ks("(
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return items; 5de1r B|
} =liyd74%`
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publicvoid setItems(List items){ +X+R8
this.items = items; h*D -Vo
} $*$4DG1gaR
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publicint getPageSize(){ XUh&an$
return pageSize; ^ H2TSaJ;
} xu"-Uj1
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publicvoid setPageSize(int pageSize){ r}e(MT:R'
this.pageSize = pageSize; Q?LzL(OioN
} K3h];F!^
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publicint getTotalCount(){ "Dk@-Ac
return totalCount; ^Ss<<
} PPrvVGP
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publicvoid setTotalCount(int totalCount){ T"3LO[j+
if(totalCount > 0){ bv(+$YR
this.totalCount = totalCount; E&z^E2
int count = totalCount / FZ<6 kk4
ib
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pageSize; BR?DW~7J j
if(totalCount % pageSize > 0) v(JjvN21
count++; fV7
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indexes = newint[count]; 2?Ryk`2i)
for(int i = 0; i < count; i++){ U?|A3;,xh
indexes = pageSize * "k
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i; e@vZg8Ie
} |}e"6e%
}else{ uEr.LCAS
this.totalCount = 0; ~H?v L c;>
} #P z'-lo
} CE
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publicint[] getIndexes(){
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return indexes; fj(WHL
} r/0#D+A
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publicvoid setIndexes(int[] indexes){ N;P/$
this.indexes = indexes; y
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} k5bv57@
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publicint getStartIndex(){ {Fyw<0 [@
return startIndex; s2QgR37s>
} \8a014
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publicvoid setStartIndex(int startIndex){ imwn)]L R
if(totalCount <= 0) o](ORS$~
this.startIndex = 0; !IC
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elseif(startIndex >= totalCount) ^iWGGnGS
this.startIndex = indexes bzZdj6>kX
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[indexes.length - 1]; Bs`='w%7
elseif(startIndex < 0) WTt
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this.startIndex = 0; K^GvU 0\
else{ iH]0
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this.startIndex = indexes 1
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[startIndex / pageSize]; -~\7ZRP8
} 54TWFDmGi
} ;YQ6X>
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publicint getNextIndex(){ >tL"8@z9
int nextIndex = getStartIndex() + X,o ]tgg=
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pageSize; iK'A m.o+
if(nextIndex >= totalCount) 9S'\&mRl
return getStartIndex(); #&S<{75A
else B}p.fE
return nextIndex; 6OPNP0@r
} yfFe%8w_vw
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publicint getPreviousIndex(){ +U<Ae^V
int previousIndex = getStartIndex() - n],cs
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pageSize; 7|"G
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if(previousIndex < 0) aa!1w93?i
return0;
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else V)`Q0}
return previousIndex; +&_n[;
} YWi Y[
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} :t+LuH g
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抽象业务类 !g>mjD
java代码: <bv9X?U
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/** GBd
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* Created on 2005-7-12 B]7QOf"
*/ &\/}.rF
package com.javaeye.common.business; rHjR 4q
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import java.io.Serializable; .J5or
import java.util.List; NH1|_2
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import org.hibernate.Criteria; V+*1?5w
import org.hibernate.HibernateException; )OGO
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import org.hibernate.Session; &j{IG`Trl
import org.hibernate.criterion.DetachedCriteria; F20%r 0
import org.hibernate.criterion.Projections; f%YD+Dt_V
import <lPHeO<^]
)=,;-&AR
org.springframework.orm.hibernate3.HibernateCallback; +#'QP#
import Xd~li fF
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org.springframework.orm.hibernate3.support.HibernateDaoS zq#gf
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upport; O,I7M?dRf
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import com.javaeye.common.util.PaginationSupport; .M\0+,%/
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public abstract class AbstractManager extends )7rMevF(xJ
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HibernateDaoSupport { R*O6Z"h
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privateboolean cacheQueries = false; uC`)?f*I
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privateString queryCacheRegion; z]i/hU
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publicvoid setCacheQueries(boolean KR4 RIJZ_t
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cacheQueries){ ]b&qC
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this.cacheQueries = cacheQueries; e=Kr>~q=
} 'BEM:1)
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publicvoid setQueryCacheRegion(String UFa 00t^5
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queryCacheRegion){ <{1 3Nd'o
this.queryCacheRegion = n] n3/wpO
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queryCacheRegion; `&/ zOMp
} FkoN+\d
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publicvoid save(finalObject entity){ jZ69sDhE
getHibernateTemplate().save(entity); qjvIp-
} B;L^!sLP
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publicvoid persist(finalObject entity){ VoUAFEcs
getHibernateTemplate().save(entity); C?b_E
} g\,HiKBXd
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publicvoid update(finalObject entity){ Hn(L0#Oqy
getHibernateTemplate().update(entity); }*0*8~Q'5
} =CO#Q$
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publicvoid delete(finalObject entity){ af7\2g3*
getHibernateTemplate().delete(entity); ~E7=c3:"
} r+Y]S-o:
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publicObject load(finalClass entity, !O8vr4=
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finalSerializable id){ q|ZQsFZ
return getHibernateTemplate().load ^S`c-N
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(entity, id); =
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} R:DW>LB
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publicObject get(finalClass entity, })r[qsv
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finalSerializable id){ utwqP~
return getHibernateTemplate().get 9Fxz9_ i
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(entity, id); !.k
} ~x}=lK N
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publicList findAll(finalClass entity){ X*C4NF0
return getHibernateTemplate().find("from F%QVn.
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" + entity.getName()); %S4pkFR
} -T-h~5
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publicList findByNamedQuery(finalString )<jT;cT!&
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namedQuery){ kQm\;[R
return getHibernateTemplate enJE#4Z5&s
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().findByNamedQuery(namedQuery); 47XQZ-}4
} #r)c@?T@j
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publicList findByNamedQuery(finalString query, P/FO, S-V
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finalObject parameter){ 6*2z^P9FRj
return getHibernateTemplate I6FglVQ6
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().findByNamedQuery(query, parameter); } Pc6_#
} &wZ:$lK#o
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publicList findByNamedQuery(finalString query, fXYg %
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finalObject[] parameters){ TNV#
return getHibernateTemplate Si]8*>}-B
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().findByNamedQuery(query, parameters); asI:J/%+2
} u37@9
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publicList find(finalString query){ ghiFI<)VY
return getHibernateTemplate().find wLC|mByq
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(query); .HG0%Vp
} @[S\ FjI
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publicList find(finalString query, finalObject dDy9yw%f?
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parameter){ #3u;Ox
return getHibernateTemplate().find o^},L?
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(query, parameter); |L7
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} P Z;O
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public PaginationSupport findPageByCriteria S-:l
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(final DetachedCriteria detachedCriteria){ *Ta*0Fr=9|
return findPageByCriteria 0BIH.ZV#
X(#G6KeZFZ
(detachedCriteria, PaginationSupport.PAGESIZE, 0); @$;"nVZ4v
} M(S:&GOU
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public PaginationSupport findPageByCriteria mY3x
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(final DetachedCriteria detachedCriteria, finalint j4Cad
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startIndex){ $3%EKi
return findPageByCriteria l23#"gGb
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(detachedCriteria, PaginationSupport.PAGESIZE, Zcv1%hI
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startIndex); ?+b )=Z
} g(MeCoCc
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public PaginationSupport findPageByCriteria dM 7-,9Vc
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(final DetachedCriteria detachedCriteria, finalint f|_iHY
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pageSize, }dE0WJcO
finalint startIndex){ FbHk6(/)
return(PaginationSupport)
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getHibernateTemplate().execute(new HibernateCallback(){ %Sfew/"R0
publicObject doInHibernate -mG3#88*
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(Session session)throws HibernateException { rRL:]%POT
Criteria criteria = qI"@ PI!s
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detachedCriteria.getExecutableCriteria(session); a!P?RbW
int totalCount = s&!g )
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((Integer) criteria.setProjection(Projections.rowCount O%y.
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()).uniqueResult()).intValue(); FU~ Ip
criteria.setProjection izow=}
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(null); S!k cC-7
List items = o6ec\v!l-
d?*=<w!A
criteria.setFirstResult(startIndex).setMaxResults \:\rkc9LI
sUcx;<|BC
(pageSize).list(); 9dr\=e6) C
PaginationSupport ps = z'MOuz~Y
x(&o=Pu
new PaginationSupport(items, totalCount, pageSize, ZPY#<^WOzr
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startIndex); p0UR5A>p
return ps; Edc< 8-
} J O`S
}, true); : }v&TQ
} ">*PH}b
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public List findAllByCriteria(final kc\^xq~
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DetachedCriteria detachedCriteria){ [GX5jD#
return(List) getHibernateTemplate _1f!9ghT\
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().execute(new HibernateCallback(){ egxh
publicObject doInHibernate sME3s-
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(Session session)throws HibernateException { U|={LU
Criteria criteria = #)2'I`_E
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detachedCriteria.getExecutableCriteria(session); fn(KmuNA
return criteria.list(); |[;9$Vn
} +HQX]t:Y
}, true); lO9ML-8C1
} 5\V>Sj(
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public int getCountByCriteria(final Tf)qd\
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DetachedCriteria detachedCriteria){ )'KkO$^&
Integer count = (Integer) \m~?mg"#
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getHibernateTemplate().execute(new HibernateCallback(){ r1yz ?Y_P
publicObject doInHibernate M3c-/7
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(Session session)throws HibernateException { /\V-1 7-
Criteria criteria = (PE x<r1
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detachedCriteria.getExecutableCriteria(session); @-Tt<pl'L
return 6Lr G+p`
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criteria.setProjection(Projections.rowCount 'kf]l=i[n
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()).uniqueResult(); Cb5;l~}L
} {M96jjiInf
}, true); /qa{*"2Qo
return count.intValue(); YD_hg#=n
} lO! Yl:;m%
} ]*|+06
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用户在web层构造查询条件detachedCriteria,和可选的 I !=ew |
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 U1}-]^\
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PaginationSupport的实例ps。 ?55t0
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ps.getItems()得到已分页好的结果集 gQMcQV]C$
ps.getIndexes()得到分页索引的数组 ^<49NUB>
ps.getTotalCount()得到总结果数 FD:3;nUY7
ps.getStartIndex()当前分页索引 GX?R# cf
ps.getNextIndex()下一页索引 z{Z4{&M
ps.getPreviousIndex()上一页索引 \ :To\6\Ri
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 $`,10uw
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 :}'5'oVG
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一下代码重构了。 KT$Za
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我把原本我的做法也提供出来供大家讨论吧: ovm109fTx
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首先,为了实现分页查询,我封装了一个Page类: 4eH:eCZze
java代码: @h7)M:l
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/*Created on 2005-4-14*/ oGt,^!V1
package org.flyware.util.page; 1T&NU
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/** Y;2WY0eq
* @author Joa $eHYy,,
* }C-K0ba7
*/ rlxZ,]ul
publicclass Page { FM$$0}X
#uTNf78X
/** imply if the page has previous page */ _L?MYkD
privateboolean hasPrePage; (D2G.R\pr
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/** imply if the page has next page */ #gW"k;7P
privateboolean hasNextPage; 8/W(jVO(-
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/** the number of every page */ DO*rVs3'p[
privateint everyPage; %Q,6 sH#
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/** the total page number */ [B~*88T
privateint totalPage; Wo)$*?
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/** the number of current page */ x[u4>f
privateint currentPage; 7R5m|h`M
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/** the begin index of the records by the current ob3)bI oM
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query */ Hk&op P9)
privateint beginIndex; e= { ?d6
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/** The default constructor */ UHyGW$B
public Page(){ qa-%j +
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} jVlXB6[-
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/** construct the page by everyPage aH/8&.JLi
* @param everyPage ;Mw<{X-
* */ Ms<v81z5T
public Page(int everyPage){ 79&=MTM
this.everyPage = everyPage; C#qF&n
} i.Rxx, *?
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/** The whole constructor */ @LSfP
public Page(boolean hasPrePage, boolean hasNextPage, B:)PUBb
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int everyPage, int totalPage, SI`ems{1>c
int currentPage, int beginIndex){ H0(.p'eN
this.hasPrePage = hasPrePage; ^O0trM>h-
this.hasNextPage = hasNextPage; @`mr|-Rp@
this.everyPage = everyPage; pk8`suZ
this.totalPage = totalPage; hZIbN9)8A
this.currentPage = currentPage; L;\f^v(
this.beginIndex = beginIndex; ]ZR}Pm/CA
} dzk1 !yy
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/** t
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* @return `}:pUf
* Returns the beginIndex.
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*/ cqYMzS
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publicint getBeginIndex(){ P(oGNKAS
return beginIndex; 4V<.:.k
} 9y'To JZ6
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/** Y sDai<
* @param beginIndex %y)]Q|
* The beginIndex to set. sWyx_
*/ F4NMq&_
publicvoid setBeginIndex(int beginIndex){ 'QSj-
this.beginIndex = beginIndex; 7Y?59
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} _U|rTil
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/** xLdkeuL[%
* @return %MCJ%Ph
* Returns the currentPage. &8;Fi2}(L
*/ /z
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publicint getCurrentPage(){ g-pEt#
return currentPage; h e=A%s
} [jz@d\k$_
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/** }0[<xo>K
* @param currentPage P^aNAa
* The currentPage to set. j];#=+
*/ (fYYcpd,k
publicvoid setCurrentPage(int currentPage){ q*K[?
this.currentPage = currentPage; ,\-4X
} 18^K!:Of
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/** ug_c}Nv=Y
* @return i,zZJ=a$
* Returns the everyPage. a8YFH$Xh
*/ CZ!gu Y=
publicint getEveryPage(){ naiQ$uq0
return everyPage; m2%n:
} %!7A" >ai
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/** zh{I;~syh
* @param everyPage (M?VB*sm0
* The everyPage to set. ov5g`uud
*/ \#v(f2jPF
publicvoid setEveryPage(int everyPage){ *:%I|5
this.everyPage = everyPage; Z,-J
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} UGxF}Q
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/** ai<K6)
* @return e6>[Z C
* Returns the hasNextPage. ;Kh[6{ W
*/ 8%`h:fE
publicboolean getHasNextPage(){ %J+ w9Z
return hasNextPage; F0wW3+G
} -k
}LW4
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/** I^)_rOgM
* @param hasNextPage Rzyaicj^c
* The hasNextPage to set. .NJ Ne
*/ cSBS38>
publicvoid setHasNextPage(boolean hasNextPage){ B1j^qoC.5
this.hasNextPage = hasNextPage; IrIW>r} -
} l*Q OM
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p
/** iA|n\a~ny,
* @return B~E>=85z
* Returns the hasPrePage. Nx zAlu
*/ 24po}nrO
publicboolean getHasPrePage(){ sDvy(5
return hasPrePage; cJ>^@pd{
} tiy#b8
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/** /g1;`F(MS/
* @param hasPrePage I-Q(kWc
* The hasPrePage to set. L<G6)'5W
*/ i)/#u+Y1P
publicvoid setHasPrePage(boolean hasPrePage){ (S?qxW?
this.hasPrePage = hasPrePage; aI;fNy/K
} t]{, 7.S
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/** a# Uk:O!
* @return Returns the totalPage. C,8@V`
* #^_7i)=~
*/ F ~e}=Nb
publicint getTotalPage(){ *l@T
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return totalPage; (SCZ.G(>
} @.=2*e.z|b
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/** bo??91B^7
* @param totalPage "HLh3L~
* The totalPage to set. 5>:p'zI
*/ Va4AE)[/*
publicvoid setTotalPage(int totalPage){ -j^G4J
this.totalPage = totalPage; _QtW)\)5\
} V0bKtg1f?-
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} >J,IxRGi
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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 CX 7eCo
=T$2Qo8
个PageUtil,负责对Page对象进行构造: BOl*. t
java代码: P#/s5D8
sDwE,f0h
IFXn GDG$
/*Created on 2005-4-14*/ 'h>l_A
package org.flyware.util.page; i7?OZh*f
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import org.apache.commons.logging.Log; ?#:!!.I:
import org.apache.commons.logging.LogFactory; L(/wsw~y*
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/** "^t;V+Io
* @author Joa R?] S<Z
* ?' $}k
*/ Ut(BQM>U+$
publicclass PageUtil { b:&=W>r
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privatestaticfinal Log logger = LogFactory.getLog hAB:;r XlI
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(PageUtil.class); I^O`#SA (
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/** !/"y
* Use the origin page to create a new page +7t: /_b~
* @param page S3dcE"hg
* @param totalRecords Egl1$,e
* @return i;#AW($+a
*/ UvGX+M,z'
publicstatic Page createPage(Page page, int CasFj9,
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totalRecords){ tY?evsVgz
return createPage(page.getEveryPage(), 6}_J;g\|
}
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page.getCurrentPage(), totalRecords); af/;D r@
} >;X^+JH!)
7 v(<<>
/** wHErF
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* the basic page utils not including exception z6OJT6<'
!Mk]%
handler peU1
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* @param everyPage l 4cTN
@E
* @param currentPage 6
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* @param totalRecords oX-h7;SD
* @return page {Yti
*/ 3
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publicstatic Page createPage(int everyPage, int 1c $iW>0K
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currentPage, int totalRecords){ gjy:o5{vA*
everyPage = getEveryPage(everyPage); q%FXox~b
currentPage = getCurrentPage(currentPage); 7=4V1FS6i
int beginIndex = getBeginIndex(everyPage, j,g.Eo
E"%G@,|3*
currentPage); -\~x^5K
int totalPage = getTotalPage(everyPage, YfH+kDT
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totalRecords); -GL-&^3IjH
boolean hasNextPage = hasNextPage(currentPage, f>+:UGmP
oz?6$oE(bt
totalPage); M+\LH
boolean hasPrePage = hasPrePage(currentPage); 5?MKx!%
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returnnew Page(hasPrePage, hasNextPage, :;Wh!8+j
everyPage, totalPage, G6j9,#2@
currentPage, UyOoyyd.
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beginIndex); YRP$tz+
_
} j*1O(p+
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privatestaticint getEveryPage(int everyPage){ b %I2ig
return everyPage == 0 ? 10 : everyPage; .sbV<ulbc
} M{~KT3c
a.g:yWL\
privatestaticint getCurrentPage(int currentPage){ -\fn \n
return currentPage == 0 ? 1 : currentPage; }MV=t7x9+
} T8J[B( )L
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privatestaticint getBeginIndex(int everyPage, int ,xIWyI.
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currentPage){ s&WHKCb
return(currentPage - 1) * everyPage; 9@z"~H
} TWJ%? /d
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privatestaticint getTotalPage(int everyPage, int v]BMET[w
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totalRecords){ u:&Lf
int totalPage = 0; G |vG5$Nf
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if(totalRecords % everyPage == 0)
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totalPage = totalRecords / everyPage; T=->~@5
else FG5t\!dt<
totalPage = totalRecords / everyPage + 1 ; )3~):+
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return totalPage; 2M+'9+k~
} v/WvT!6V`
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privatestaticboolean hasPrePage(int currentPage){ E14Dq#L
return currentPage == 1 ? false : true; ~uz 4
} 2:l8RH!Y
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privatestaticboolean hasNextPage(int currentPage, [ !#<nY/C
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int totalPage){ 4&([<gyR<
return currentPage == totalPage || totalPage == !5K9L(gqb
9;u&,R
0 ? false : true; }e* OprF
} X,h"%S<c#H
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} m`Ver:{
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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。 /^<Uy3F[p
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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 \P|PAU@,
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做法如下: B#K{Y$!v
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 qKg*/)sD(
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的信息,和一个结果集List: 3KW4 ]qo~
java代码: gK8{ =A0c
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/*Created on 2005-6-13*/ &{c.JDO
package com.adt.bo; hf~'EdU
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import java.util.List; P[E5e+A)
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import org.flyware.util.page.Page; 3,<$z1Jm
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/** $Dm2>:Dmt
* @author Joa j!:^+F/
*/ &6`h%;a/&
publicclass Result { 58@YWvAk
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private Page page; >qBQfz:U>
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private List content; Io81zA
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/** #DI%l`B
* The default constructor U- UD27
*/ S_VZ^1X]
public Result(){ u2G{I?
super(); :mwJJIjUW
} y7quKv7L}
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/** Xv%1W?
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* The constructor using fields ,MxTT!9Su
* uoM;p'
* @param page 8i=c|k,GL.
* @param content >vP DF+ u
*/ *?a rEYc8
public Result(Page page, List content){ b!7*bFTt
this.page = page; 69{BJ]q
this.content = content; x"9e eB,
} oK5"RW
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/** 8tR(i[L
* @return Returns the content. <