Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 =l43RawAmu
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 F9j@KC(yg
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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 =6dAF"b)
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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 )%@7tx
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分页支持类: IrL%0&*hS
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java代码: g9" wX?*
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package com.javaeye.common.util; vWoppt
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import java.util.List; Q[#}Oh6$
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publicclass PaginationSupport { XZKlE
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publicfinalstaticint PAGESIZE = 30; P'qBqx[
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privateint pageSize = PAGESIZE; xZ`z+)
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privateList items; t\ oud{Cv
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privateint totalCount; .3C::~:
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privateint[] indexes = newint[0]; ,kJ7c;:i
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privateint startIndex = 0; CK n2ZL
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public PaginationSupport(List items, int R0INpF';
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totalCount){ |`:cB
setPageSize(PAGESIZE); 62HA[cr&)
setTotalCount(totalCount); 06]3+s{{
setItems(items); E'aOHSAg
setStartIndex(0); X\Bl?
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} .hmeP
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public PaginationSupport(List items, int "6'",
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totalCount, int startIndex){ !s-A`}
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setPageSize(PAGESIZE); tG$O[f@U6
setTotalCount(totalCount); [gBf1,bK
setItems(items); A6=Z2i0w>X
setStartIndex(startIndex); |,,#DSe
} Z2M(euzfi3
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public PaginationSupport(List items, int k";dK*hD,
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totalCount, int pageSize, int startIndex){ H*N <7#
setPageSize(pageSize); P6GTgQ<'BA
setTotalCount(totalCount); ooJxE\L
setItems(items); `'s_5Ek
setStartIndex(startIndex); D Yf2V6'
} >;4q
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publicList getItems(){ 68z#9}
return items; Sqn>L`Lz
} mvjx
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publicvoid setItems(List items){ 9Do75S{(
this.items = items; $^fF}y6N
} 1TQ?Fxj
x 4v:67_^
publicint getPageSize(){ &)k=ccm
return pageSize; #`3Q4
} J-<P~9m~I
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publicvoid setPageSize(int pageSize){ KhWy
this.pageSize = pageSize; hn2:@^=f
} g*b`o87PI
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publicint getTotalCount(){ r:V
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return totalCount; L!xFhVA<
} Q (f0S
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publicvoid setTotalCount(int totalCount){ H"/J R
if(totalCount > 0){ aaU4Jl?L
this.totalCount = totalCount; ]z'L1vQl7
int count = totalCount / :Ob4WU
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pageSize; T@ESMPeU:X
if(totalCount % pageSize > 0) k4$zM/ob
count++; q+9^rQ
indexes = newint[count]; x,^-a
for(int i = 0; i < count; i++){ =Lkn
indexes = pageSize * AHs%?5YTY;
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i; !LH;K
} lx2#C9L_
}else{ /4Wf\
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this.totalCount = 0; $EY[CA
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} R8[VD iM6E
} 0 8L;u7u
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publicint[] getIndexes(){ qWW\d', .
return indexes; P WS8Dpb
} H'3
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publicvoid setIndexes(int[] indexes){ _:\rB
this.indexes = indexes; Q(<A Yu
} 'G65zz
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publicint getStartIndex(){ E&J<qTH9
return startIndex; RTVU3fw
} 4Vi*Qa_,y
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publicvoid setStartIndex(int startIndex){ 2j4202
if(totalCount <= 0) &PPnI(s^K
this.startIndex = 0; lB _9b_|2
elseif(startIndex >= totalCount) ?H8w;Csq-
this.startIndex = indexes 4e>f}u5
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[indexes.length - 1]; >A D!)&c
elseif(startIndex < 0) #8t=vb3
this.startIndex = 0; XwEMF5[
else{ D>jtz2y=D
this.startIndex = indexes Ch?yk^cY
iyCH)MA
[startIndex / pageSize]; KLM6#6`
} z#RwgSPw6
} MX~h>v3_R4
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publicint getNextIndex(){ 'KmM%tN
int nextIndex = getStartIndex() + 7|=SZ+g
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}
pageSize; $xW9))
if(nextIndex >= totalCount) 0(c,J$I]Z!
return getStartIndex(); &kdW(;`
else G$YF0Nc
return nextIndex; NUnwf
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} qDGx(d
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publicint getPreviousIndex(){ 8Q/cJ+&
int previousIndex = getStartIndex() - 4?@5JpC9VA
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pageSize; 2Ax(q&`9
if(previousIndex < 0) )xc1Lsrr9
return0; axnVAh|}S
else ]NaH *\q
return previousIndex; JT}"CuC
} x!I@cP#O
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} ,hNs{-*
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抽象业务类 =^M Q 4
java代码: ?_{{iil
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/** Se??E+aX
* Created on 2005-7-12 85"Szc-#
*/ |C./gdq
package com.javaeye.common.business; 7h/Mkim$5
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import java.io.Serializable; um PN=0u6
import java.util.List; nUq@`G
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import org.hibernate.Criteria; 'O ~_g5kC
import org.hibernate.HibernateException; Q%'4jn?H
import org.hibernate.Session; w'i+WEU>l
import org.hibernate.criterion.DetachedCriteria; agoMsxI9
import org.hibernate.criterion.Projections; g>ke;SH%KY
import KxmB$x5-=8
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org.springframework.orm.hibernate3.HibernateCallback; )@B!
import
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org.springframework.orm.hibernate3.support.HibernateDaoS @(/$;I,
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upport; N}z]OvnZH
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import com.javaeye.common.util.PaginationSupport; (Gzq 1+B
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public abstract class AbstractManager extends t P'._0n0
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HibernateDaoSupport { H5FWk
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privateboolean cacheQueries = false; V-%jSe<
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privateString queryCacheRegion; nm|"9|/
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publicvoid setCacheQueries(boolean s?sr0HZ
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cacheQueries){ ,mp^t2
this.cacheQueries = cacheQueries; eZpi+BRS6
} 0*OK]`9
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publicvoid setQueryCacheRegion(String l>Zp#+I-
@MH/efW.
queryCacheRegion){ '}Jq(ah(
this.queryCacheRegion = ;M#D*<ucI:
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queryCacheRegion; gU@.IOg
} ~:="o/wo
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publicvoid save(finalObject entity){ a,t]> z95
getHibernateTemplate().save(entity); t(^Lh.<a
} 7BgA+Fz
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publicvoid persist(finalObject entity){ :n}t7+(>U
getHibernateTemplate().save(entity); UD'e%IVw
} lt l(SIi
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publicvoid update(finalObject entity){ <~5$<L4
getHibernateTemplate().update(entity); fJ-8$w\uL
} 6:bvq?5a5
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publicvoid delete(finalObject entity){ Zg;Ht
getHibernateTemplate().delete(entity); bu\D*-
} g;nPF*(
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publicObject load(finalClass entity, `t#Ie*
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finalSerializable id){ @aoHz8K
return getHibernateTemplate().load D7N` %A8
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(entity, id); '6>nXp?)r
} 4d]T`
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publicObject get(finalClass entity, rI1;>/Ir
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finalSerializable id){ JA?P jo
return getHibernateTemplate().get WB|SXto%4D
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(entity, id); w5&,AL:
} "j+=py`
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publicList findAll(finalClass entity){ *j|BSd
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return getHibernateTemplate().find("from 8:UV; 5@
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" + entity.getName()); ]?2&d[
} S|v-lJ/I
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publicList findByNamedQuery(finalString ki_Py5
}~ o>H a;
namedQuery){ W-U[7n
return getHibernateTemplate H!{Cr#=
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().findByNamedQuery(namedQuery); 3Q(#2tL=
} rsvGf7C
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publicList findByNamedQuery(finalString query, WAbt8{$D
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finalObject parameter){ }q@Jh*
return getHibernateTemplate ,`< [ej
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().findByNamedQuery(query, parameter); >sE{c>R%
} )0Lv-Gs
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publicList findByNamedQuery(finalString query, fDY#&EO: %
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finalObject[] parameters){ hAp<$7
return getHibernateTemplate KGb3n;]
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().findByNamedQuery(query, parameters); H23-%+*J
} -^LEGKN
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publicList find(finalString query){ }<kpvd+ps=
return getHibernateTemplate().find m-No 8)2yA
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(query); "S@%d(lg
} ~nG?>
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publicList find(finalString query, finalObject ]`Y;4XR
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parameter){ K%A:W
return getHibernateTemplate().find hK&/A+*
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(query, parameter); ]\<^rEU
} ?-0>Wbg
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public PaginationSupport findPageByCriteria f#UT~/~bL2
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(final DetachedCriteria detachedCriteria){ cvvba 60
return findPageByCriteria lf\]^yM #
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); aJ1<X8
} n089tt=TE
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public PaginationSupport findPageByCriteria />zE$)'M
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(final DetachedCriteria detachedCriteria, finalint jn9KQe\3
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startIndex){ V'4sOn
return findPageByCriteria Q}M%
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(detachedCriteria, PaginationSupport.PAGESIZE, \j]i"LpWb
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startIndex); gUB%6v G\I
} Gt^Fj&^
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public PaginationSupport findPageByCriteria q8{)27f,
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(final DetachedCriteria detachedCriteria, finalint UmSy p\i
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pageSize, g9`z]qGWS:
finalint startIndex){ 4~3 N;]X
return(PaginationSupport) J
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getHibernateTemplate().execute(new HibernateCallback(){ /MB3w m
publicObject doInHibernate ['~B&
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(Session session)throws HibernateException { #,1Kum
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Criteria criteria = $ Aw"?&d"
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detachedCriteria.getExecutableCriteria(session); r_f?H@ v
int totalCount = 3U0>Y%m| ,
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((Integer) criteria.setProjection(Projections.rowCount kqfO3{-;{:
[wJM=`!W
()).uniqueResult()).intValue(); MV<2x7S
criteria.setProjection $]eITyC`P
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(null); -#
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List items = V(|@6ww
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criteria.setFirstResult(startIndex).setMaxResults <0r2m4z
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(pageSize).list(); mjDaus59
PaginationSupport ps = tk@
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new PaginationSupport(items, totalCount, pageSize, -rSpgk0wL
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startIndex); j>(O1z7
return ps; )
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} 0L_JP9e
}, true); N|OI~boV%
} 6\7bE$K
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public List findAllByCriteria(final A~_*vcz
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DetachedCriteria detachedCriteria){ ]3xb Q1
return(List) getHibernateTemplate (*>%^ C?
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().execute(new HibernateCallback(){ gJE m
publicObject doInHibernate J3OxM--8"
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(Session session)throws HibernateException { eM";P/XaX
Criteria criteria = B8){
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detachedCriteria.getExecutableCriteria(session); 5hN`}Ve
return criteria.list(); RjC3wO::
} 1 PL2[_2:
}, true); `52+.*J+%
} )YE3n-~7{
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public int getCountByCriteria(final q#RUL!WF7U
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DetachedCriteria detachedCriteria){ s9R#rwIc
Integer count = (Integer) J!40`8i
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getHibernateTemplate().execute(new HibernateCallback(){ zPzy0lx
publicObject doInHibernate &\8qN_`
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(Session session)throws HibernateException { x3j)'`=15
Criteria criteria = J:<mq5[
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detachedCriteria.getExecutableCriteria(session); ws1io.
return l`S2bb6uMR
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criteria.setProjection(Projections.rowCount )k)HQcfjD
}H^h~E
()).uniqueResult(); h0m+u}oP_H
} <$6r1y*G
}, true); {kCCpU
return count.intValue(); a_jw4"Sb
} |\/`YRg>
} gEghDO_G
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用户在web层构造查询条件detachedCriteria,和可选的 ?A4zIJ\
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 `fTH"l1zn
" Y%fk/v8
PaginationSupport的实例ps。 '%Cc!63t*
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ps.getItems()得到已分页好的结果集 ~
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ps.getIndexes()得到分页索引的数组 2/Xro rV
ps.getTotalCount()得到总结果数 b 6kDkE
ps.getStartIndex()当前分页索引 tu5g> qb
ps.getNextIndex()下一页索引 " pg5w
ps.getPreviousIndex()上一页索引 ~e|RVY,
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 .r ,wc*SF
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 |ry![\
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一下代码重构了。 @:,B /B;
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我把原本我的做法也提供出来供大家讨论吧: k^VL{z:EWB
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首先,为了实现分页查询,我封装了一个Page类: `$PdI4~J
java代码: azhilUD8
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/*Created on 2005-4-14*/ >X@4wP7l
package org.flyware.util.page; RSfB9)3D
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/** DT;n)7+,
* @author Joa ;H' ,PjU
* _ *l+ze[a
*/ >Hr&F
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publicclass Page { h(~@
nd{
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/** imply if the page has previous page */ X%C`('"R
privateboolean hasPrePage; XE#a#
plNoI1st
/** imply if the page has next page */ 8}M-b6RV
privateboolean hasNextPage; MnLo{G]
*x!j:/S`n
/** the number of every page */ B~ ?R 6
privateint everyPage; oV/:T\Qn=
H*.v*ro9_
/** the total page number */ K#%@4]jO3
privateint totalPage; C.|.0^5
q1^bH6*fl
/** the number of current page */ ,kQCCn]
privateint currentPage; 2y"L&3W
]
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/** the begin index of the records by the current *P01 yW0
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query */ UuKW`(?^
privateint beginIndex; /4I9Elr
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/** The default constructor */ >b7Yk)[%
public Page(){ xe4`D>LUo
9^?2{aP%
} SuR+Vv
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/** construct the page by everyPage w#d7
* @param everyPage !U7}?i&H
* */ mI,a2wqi
public Page(int everyPage){ rff_=(?i
this.everyPage = everyPage; SpO%nZ";g8
} h
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/** The whole constructor */ eK[9wEdn
public Page(boolean hasPrePage, boolean hasNextPage, iBPIj;,
*ZkOZ
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int everyPage, int totalPage, H73 r3BH
int currentPage, int beginIndex){ Pk3b#$+E
this.hasPrePage = hasPrePage; ^/ff)'.J
this.hasNextPage = hasNextPage; :@b=;
this.everyPage = everyPage; t`-
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this.totalPage = totalPage; 'WNq/z"X
this.currentPage = currentPage; tjLG$M1z`
this.beginIndex = beginIndex; !ra,HkU'
} J[{ R:l\
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/** A I v
* @return g8R@ol0
* Returns the beginIndex. 8 \"A-+_Q
*/ I]z4}#+cX
publicint getBeginIndex(){ hg7_ZjO
return beginIndex; oe*fgk/o9
} 3:aj8F2
QQ/9ZI5
/** (kVxa8 0
* @param beginIndex kr\#CW0?
* The beginIndex to set. !GJT-[
*/ Q 5&|1m Pb
publicvoid setBeginIndex(int beginIndex){ ctoh&5%!n+
this.beginIndex = beginIndex; W%1/:_
} |fB/ hs \
l h?[wc
/**
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* @return 5FVmk5z]d
* Returns the currentPage. q:1n=iEi
*/ m f\tMik<
publicint getCurrentPage(){ g;7W%v5wqk
return currentPage; U
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} D/ tCB-+
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/** b5#Jo2C`AJ
* @param currentPage kpRk.Q*
* The currentPage to set. Jsa;pG=3&
*/ Byh!Snoe
publicvoid setCurrentPage(int currentPage){ OWp`Wat
this.currentPage = currentPage; E&ReQgBft
} -nZDFC8y$
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/** eF(oHn,
* @return NE><(02qW
* Returns the everyPage. Z kBWVZb
*/ OGcW]i
publicint getEveryPage(){ ;D<;pW
return everyPage; l\TL=8u2c
} 6n\){dkZ~
5~OKKSUmT
/** Jv8VM\*
* @param everyPage VHLt,?G
* The everyPage to set. yuhY )T
*/ O[$XgPM
publicvoid setEveryPage(int everyPage){ l>6p')F!
this.everyPage = everyPage; t^=S\1"R\
} ,uD}1
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/** ;3iWV"&_A
* @return Q$5%9
* Returns the hasNextPage. braI MIQ`
*/ FzF#V=9lP
publicboolean getHasNextPage(){ %v0;1m
return hasNextPage; ";upu
} a{Y8hR
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/** /2cn`dR,
* @param hasNextPage wauM|/KG
* The hasNextPage to set. <.{OIIuk
*/ T[-Tqi NT
publicvoid setHasNextPage(boolean hasNextPage){ $,o@&QT?AT
this.hasNextPage = hasNextPage; v
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} sRQ4pnnrn
Ev T"+;9/p
/** ($!g= 7
* @return ;)vs=DK:)
* Returns the hasPrePage. 4O4}C#6(4
*/ )"g @"LJ=
publicboolean getHasPrePage(){ ?z3|^oU~d
return hasPrePage; U^Iq]L
} IH"_6s#$&
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/** EiS2-Uh*TT
* @param hasPrePage z3M6<.K
* The hasPrePage to set. ?[.g~DK,
*/ KDr)'gl&
publicvoid setHasPrePage(boolean hasPrePage){ V$ho9gQ!l[
this.hasPrePage = hasPrePage; !,~C
} Gw#z:gX2
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/** 5*O]`Q7
* @return Returns the totalPage. +D?Re%HI
* 6?-,@e
*/ `a8 &7J(
publicint getTotalPage(){ 91ec^g
return totalPage; y(j vl|z[
} i x_a
jF{)2|5
/** U8eU[|-8O/
* @param totalPage &D` $YUl@
* The totalPage to set. ]_hXg*?
*/ s5ILl wr
publicvoid setTotalPage(int totalPage){ 0{u#{_
this.totalPage = totalPage; BQ{'r^u
} R4XcWx*pQ
_:Ov-HIR
} scZ'/(b-E
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 7mYBxE/
84gj%tw'-
个PageUtil,负责对Page对象进行构造: u]<`y6=&C
java代码: Jh%k:TrBm
9QkIMJf0e
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/*Created on 2005-4-14*/ CM+wkU ?,
package org.flyware.util.page; NTSKmCvQG
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import org.apache.commons.logging.Log; F:-6Htmj
import org.apache.commons.logging.LogFactory; ;W!hl<``d*
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/** j*jq2u
* @author Joa u_S>`I
* gR{.0e
*/ Mp^U)S+
publicclass PageUtil { nHB`<B
4\Cb4jq%/
privatestaticfinal Log logger = LogFactory.getLog =Y5*J#
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(PageUtil.class); XXZ$^W&
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/** I[ I]C9D
* Use the origin page to create a new page zyFbu=d|O:
* @param page Vt
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* @param totalRecords 'p(I!]"uo
* @return I\ y>I?X
*/ |p+ xM
publicstatic Page createPage(Page page, int h>K%OxR
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totalRecords){ ;?:X_C
return createPage(page.getEveryPage(), 2BIOA#@t
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page.getCurrentPage(), totalRecords); ]ipltR7k
} GGn/J&k
9!|.b::
/** wz]OM
* the basic page utils not including exception L}%4YB
Ci^tP~)&"
handler rDWqJ<8
* @param everyPage W=
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* @param currentPage y'pX/5R0
* @param totalRecords #oD*H:%*
* @return page ^k}jPc6
*/ #&c}in"!
publicstatic Page createPage(int everyPage, int }!g^}BWWp
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currentPage, int totalRecords){ kzb1iBe 6m
everyPage = getEveryPage(everyPage); iG;GAw|E
currentPage = getCurrentPage(currentPage); Xa32p_|5~
int beginIndex = getBeginIndex(everyPage, @Y2&v956
]Q\/si&
currentPage); ?{I]!gI
int totalPage = getTotalPage(everyPage, zbL6TP@=
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totalRecords); zos#B30
boolean hasNextPage = hasNextPage(currentPage, @VcSK`
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totalPage); 2*1s(Jro
boolean hasPrePage = hasPrePage(currentPage); ~2*8pb 4
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returnnew Page(hasPrePage, hasNextPage, .EUOKPK4W
everyPage, totalPage, YG6Kvc6T
currentPage, sGD b<
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beginIndex); SpUcrK;1
} M0zlB{eH
/0H39]y!~
privatestaticint getEveryPage(int everyPage){ ROHr%'owgL
return everyPage == 0 ? 10 : everyPage; ,4%'~8'3
} D;al(q
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privatestaticint getCurrentPage(int currentPage){ jVpk) ;vC
return currentPage == 0 ? 1 : currentPage; _'E,g@
} ` `R;x
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privatestaticint getBeginIndex(int everyPage, int 0BTLIV$d;
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currentPage){ V OViOD
return(currentPage - 1) * everyPage; +}@HtjM
} VJeN
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privatestaticint getTotalPage(int everyPage, int Y+tXWN"8
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totalRecords){ 8y{<M"v+/
int totalPage = 0; ctL@&~*nY
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if(totalRecords % everyPage == 0) 43Yav+G(+
totalPage = totalRecords / everyPage; \ oIVE+L/P
else }$ Am;%?p
totalPage = totalRecords / everyPage + 1 ; :d<;h:^_
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return totalPage; $h-5PwHp
} r='"X#CmV/
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privatestaticboolean hasPrePage(int currentPage){
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return currentPage == 1 ? false : true; )[>b7K$f
} B&`hvR
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privatestaticboolean hasNextPage(int currentPage, 8uX1('+T*
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int totalPage){ (Ia} ]q
return currentPage == totalPage || totalPage == iG*/m><-
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0 ? false : true; qlSc[nEk
} DH_Mll>
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}
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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。 x(z[S$6Y\
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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 I#kK! m1Q
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做法如下: 0EYK3<k9!
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象
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