Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 h(sKGCG
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 4q8%!\A+
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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 CFxs`C^
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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 f|5|n>*
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分页支持类: 3i~{x[Jc
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java代码: ,#Y".23G
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package com.javaeye.common.util; s:P-F0q!&
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import java.util.List; wE2?/wb
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publicclass PaginationSupport { z[OEgHI
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publicfinalstaticint PAGESIZE = 30; BJ/%{ C`g
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privateint pageSize = PAGESIZE; 9x<
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privateList items; SfT ]C~#$N
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privateint totalCount; ly+7klQ;.
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privateint[] indexes = newint[0]; enM 3
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privateint startIndex = 0; J(60eTwQ
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public PaginationSupport(List items, int v<4zcMv
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totalCount){ n2~rrQ
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setPageSize(PAGESIZE); E)bP}:4V
setTotalCount(totalCount); #D8)rs.9
setItems(items); )DMbO"7
setStartIndex(0); z)Gr`SA<
} ><HXd+- sd
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public PaginationSupport(List items, int =6:Iv"<
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totalCount, int startIndex){ LBR_Q0EP
setPageSize(PAGESIZE); 5E}i<}sq5
setTotalCount(totalCount); WxdYvmp6z[
setItems(items); ;H.r6
setStartIndex(startIndex); `SWK(='
} r@aFB@
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public PaginationSupport(List items, int WObfHAp.
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totalCount, int pageSize, int startIndex){ x($1pAE
setPageSize(pageSize); gV0ZZ"M
setTotalCount(totalCount); Ff30%
setItems(items); N]~q@x;<)3
setStartIndex(startIndex); fpUX
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} "]%
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publicList getItems(){ ^z1WPI
return items; WqAP'x 1
} Bvwk6NBN
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publicvoid setItems(List items){ Z1zC@z4sUj
this.items = items; I|hG"i
} =`")\?z}
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publicint getPageSize(){ @ggM5mm
return pageSize; @<+(40`*
} 'tc$#f^:
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publicvoid setPageSize(int pageSize){ aj:+"X-;
this.pageSize = pageSize; P`0aU3pl
} =y
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publicint getTotalCount(){ <K~#@.^`
return totalCount; |<S9nZg%p
} (fl2?d5+C
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publicvoid setTotalCount(int totalCount){ Sc(2c.HO*
if(totalCount > 0){ u:k#1Nn!
this.totalCount = totalCount; Ty5\zxC|
int count = totalCount / &' Ch[Wo]H
XyhdsH5%3!
pageSize; wTLHg2'y^
if(totalCount % pageSize > 0) rYT3oqpfT
count++; ]yyfE7{q
indexes = newint[count]; Y,9("'bo
for(int i = 0; i < count; i++){ v^pE=f*/
indexes = pageSize * h^4oy^9
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} ,PnEDQ|l
}else{ {.sF&(e
this.totalCount = 0; zOcMc{w0
} h`)r :a7
} 7dLPy[8";t
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publicint[] getIndexes(){ p?%G|Q
return indexes; dM)fr
} G$q=WM!%#s
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publicvoid setIndexes(int[] indexes){ t+pI<c^]y
this.indexes = indexes; ~ohW9Z1
} s)> ]'ii
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publicint getStartIndex(){ FT=w`NE,+
return startIndex; StE4n0V
} VF4F7'
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publicvoid setStartIndex(int startIndex){ Z0x N9S
if(totalCount <= 0) :f`1
this.startIndex = 0; *l|CrUa
elseif(startIndex >= totalCount) BPW:W }
this.startIndex = indexes g{&ux k);
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[indexes.length - 1]; ,5nrovv
elseif(startIndex < 0) b2z~C{l
this.startIndex = 0; ";Lpf]<
else{ he/FtkU
this.startIndex = indexes :R_(+EK1
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[startIndex / pageSize]; 7;Wj ^#
} 6$IAm#
} q4VOK
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publicint getNextIndex(){ ' e-FJ')|
int nextIndex = getStartIndex() +
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pageSize; Lq yY??\@
if(nextIndex >= totalCount) XI
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return getStartIndex(); ;i1H {hB
else :.@gd7T
return nextIndex; z}Xn>-N-
} ?g!py[CrE
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publicint getPreviousIndex(){ h!$W^Tm2g
int previousIndex = getStartIndex() - )wAqaG_d
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pageSize; ]zu"x9-`
if(previousIndex < 0) -\LB>\;qn
return0; ~v2_vEu}JX
else )t=Cj?5
return previousIndex; 2 3 P7~S
} JGJQ5zt
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} R}*e% EG/
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抽象业务类 ]XU?Wg
java代码: +DksWbD
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/** gVk_<;s
* Created on 2005-7-12 +oeO0
*/ ><dSwwu
package com.javaeye.common.business; EI]NOG 0
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import java.io.Serializable; J
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import java.util.List; z6$W@-Vd
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import org.hibernate.Criteria; x?T/=C
import org.hibernate.HibernateException; G=(F-U;*
import org.hibernate.Session; rj<r6
import org.hibernate.criterion.DetachedCriteria;
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import org.hibernate.criterion.Projections; On#RYy^}
import q*,];j/>k
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org.springframework.orm.hibernate3.HibernateCallback; _yumUk-QW
import Em-88=XO
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org.springframework.orm.hibernate3.support.HibernateDaoS //Ck1cI#h
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upport; q B5cF_
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import com.javaeye.common.util.PaginationSupport; ,ie84o
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public abstract class AbstractManager extends \2@OS6LUe
* 3WK`9q
HibernateDaoSupport { YeK PoW
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privateboolean cacheQueries = false; Z25^+)uf*U
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privateString queryCacheRegion; 1 f).J
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publicvoid setCacheQueries(boolean t L}i%7
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cacheQueries){ 4#!NVI3t
this.cacheQueries = cacheQueries; k/ls!e?
} W/OZ}ky}^
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publicvoid setQueryCacheRegion(String v=$v*W
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queryCacheRegion){ p=V (_
this.queryCacheRegion = vE^Hk!^
);'8*e'
queryCacheRegion; +h.$<=
} fE8/tx](
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publicvoid save(finalObject entity){ xQT`sK+
getHibernateTemplate().save(entity); TU&gj1
} 4Bsx[~ u&
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publicvoid persist(finalObject entity){ FhVi|Va
getHibernateTemplate().save(entity); )<nr;n
} !c(B c^
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publicvoid update(finalObject entity){ 1-!u=]JDE
getHibernateTemplate().update(entity); :''^a
} LxC*{t/>8
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publicvoid delete(finalObject entity){ #XE`8$
getHibernateTemplate().delete(entity); E=+v1\t)]
}
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publicObject load(finalClass entity, 3iMh)YH5b
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finalSerializable id){ }J$Q
return getHibernateTemplate().load x'tYf^Va28
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(entity, id); c&vY0/ [
} &W)Lzpx8c
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publicObject get(finalClass entity, 4IuQQ
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finalSerializable id){ j?K]0j;
return getHibernateTemplate().get ]~iOO
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(entity, id); q{?Po;\D
} _1S^A0ft
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publicList findAll(finalClass entity){ of!Bz
return getHibernateTemplate().find("from SO^:6GuJ
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" + entity.getName()); yu"enA
} LT']3w
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publicList findByNamedQuery(finalString ^dj
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namedQuery){ xcz[w}{eEq
return getHibernateTemplate ,g\%P5
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().findByNamedQuery(namedQuery); _7Z|=)
} xFvDKW)_X7
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publicList findByNamedQuery(finalString query, ?4vf2n@
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finalObject parameter){ UT!gAU
return getHibernateTemplate ;dgxeP;mp
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().findByNamedQuery(query, parameter); g(){wCI
} |d =1|C%,
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publicList findByNamedQuery(finalString query, *Y(v!x \L
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finalObject[] parameters){ X~wkqI#d%E
return getHibernateTemplate JsAl;w
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().findByNamedQuery(query, parameters); w],+l N;
} Y?G\@6
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publicList find(finalString query){ -?{bCq
return getHibernateTemplate().find 2~[f<N
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(query); (T+fO}0
} wn2+4> |~p
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publicList find(finalString query, finalObject 8G@I e
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parameter){ O/b~TVA
return getHibernateTemplate().find A<-Prvryt
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(query, parameter); r;m_@*]
} M| r6"~i
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public PaginationSupport findPageByCriteria tg%s#lLeH
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(final DetachedCriteria detachedCriteria){ T1'8<pJ^
return findPageByCriteria *9V;;bY#
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); D L0jA/f
} )9LlM2+y
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public PaginationSupport findPageByCriteria F|.,lb |L
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(final DetachedCriteria detachedCriteria, finalint IoUQ~JviA
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startIndex){ wX dtY
return findPageByCriteria "o.V`Bj
{@j0?s
(detachedCriteria, PaginationSupport.PAGESIZE, N0APX4j
.
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startIndex); LS1r}cl
} 5cLq6[uO
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public PaginationSupport findPageByCriteria !J<}=G5
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(final DetachedCriteria detachedCriteria, finalint %g1{nGah
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pageSize, Mle@.IIT
finalint startIndex){ oJ|8~:)
return(PaginationSupport) (Ic{C5'
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getHibernateTemplate().execute(new HibernateCallback(){ ?M2#fD]e
publicObject doInHibernate z@@w?>*
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(Session session)throws HibernateException { 'nH/Z 84
Criteria criteria = (Uk1Rt*h
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detachedCriteria.getExecutableCriteria(session); xDtq@Rb}
int totalCount = =apcMW(zn
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((Integer) criteria.setProjection(Projections.rowCount Hj&mwn]
pPr/r& r
()).uniqueResult()).intValue(); !YUMAp/
criteria.setProjection #XSs.i{
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(null); />1Ndj
List items = ="%nW3e@
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criteria.setFirstResult(startIndex).setMaxResults 0XwDk$l<
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(pageSize).list(); qf7:Q?+.|
PaginationSupport ps = 'EF\=o)^Y
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new PaginationSupport(items, totalCount, pageSize, d GEMrjx
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startIndex); C'~K am S
return ps; &=bWXNU.
} j#KL"B_A
}, true); {O\>"2}m'f
} ?,Z[)5 ZN
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public List findAllByCriteria(final c;\}R#
,PG d
DetachedCriteria detachedCriteria){ HEZgHL
return(List) getHibernateTemplate 'n'83d)z
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().execute(new HibernateCallback(){ J
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publicObject doInHibernate V=#L@ws
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(Session session)throws HibernateException { f"^G\
Criteria criteria = Y6LoPJ
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detachedCriteria.getExecutableCriteria(session); X6_m&~}15
return criteria.list(); UdBP2 lGd
} bj6-0`
}, true); Ie 3
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} H)XHlO^
#ma#oWqF }
public int getCountByCriteria(final +h!OdWD9
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DetachedCriteria detachedCriteria){ Obl']Hr{y9
Integer count = (Integer) V0'T)
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getHibernateTemplate().execute(new HibernateCallback(){ `o7m)T')
publicObject doInHibernate 8<z]rLQw?%
}(}+I}&~
(Session session)throws HibernateException { 6U{&`8C
Criteria criteria = IfyyA
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detachedCriteria.getExecutableCriteria(session); Rg/*)SKj
return 1Ql\aO)
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criteria.setProjection(Projections.rowCount u_0&`zq
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()).uniqueResult(); AEjkqG4qv
} Z4eu'.r-y~
}, true); [/.5{|&GSt
return count.intValue(); iUcDj:
} eBZ^YY<*g
} hdFIriE3
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用户在web层构造查询条件detachedCriteria,和可选的 JXR_klx
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 4AI\'M"d
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PaginationSupport的实例ps。 E1,Sr?'
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ps.getItems()得到已分页好的结果集 ym,UJs&
ps.getIndexes()得到分页索引的数组 n<C4-'^U[a
ps.getTotalCount()得到总结果数 #lA8yWxr
ps.getStartIndex()当前分页索引 &w{""'
ps.getNextIndex()下一页索引 kYxb@Zn=|
ps.getPreviousIndex()上一页索引 M[wd.\
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 2FHWOy
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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 e=b>:n
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一下代码重构了。 MPt:bf#
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我把原本我的做法也提供出来供大家讨论吧: } t4?*:\
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首先,为了实现分页查询,我封装了一个Page类: Y..
java代码: ,X Zo0!
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/*Created on 2005-4-14*/ e/@t U'$
package org.flyware.util.page; L,Jl#
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/** #bX~.jKW
* @author Joa TV$Pl[m
* (<?6X9F:N
*/ V=";vRS8
publicclass Page { ?2ZggV
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/** imply if the page has previous page */ \79KU
privateboolean hasPrePage; q$vATT
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/** imply if the page has next page */ *2O4 *Q1
privateboolean hasNextPage; F.P4c:GD
_=RA-qZ"
/** the number of every page */ t7 |uZHKK
privateint everyPage; &
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e|:#Y^
/** the total page number */ N>z<v\`
privateint totalPage; b2;+a(
k/+-Tq;
/** the number of current page */ O[O`4de9
privateint currentPage; 9W$d'IA
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/** the begin index of the records by the current $~UQKv>
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query */ 7_r$zEP6
privateint beginIndex; Kfnn;
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/** The default constructor */ ZM oV!lu
public Page(){ 5>.)7D%
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} wT?.Mte
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/** construct the page by everyPage *@'4 A :A
* @param everyPage /H+br_D9
* */ b#p)bcz!I
public Page(int everyPage){ B9`^JYT<
this.everyPage = everyPage; /60`"xH
} X+;F5b9z
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/** The whole constructor */ V$u~}]z
public Page(boolean hasPrePage, boolean hasNextPage, iTTe`Zr5y
(uG.s %I
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int everyPage, int totalPage, 3nt&Sf
int currentPage, int beginIndex){ wCiDvHF5+C
this.hasPrePage = hasPrePage; et";*EZJX
this.hasNextPage = hasNextPage; ,<$6-3sC-
this.everyPage = everyPage; ;2"#X2B
this.totalPage = totalPage; &0*l=!:G^
this.currentPage = currentPage; }J}a;P4
this.beginIndex = beginIndex; c-z2[a8
} -L>\ 58`
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/** %=x|.e@J
* @return Y%9S4be
* Returns the beginIndex. ?vL\VI9
*/ =G9%Hz5~:
publicint getBeginIndex(){ a~YFJAkg9
return beginIndex; L-_dq0T
} 0;z-I"N
yoTbIQ
/** ?29zcuRaru
* @param beginIndex @xR7>-$0p
* The beginIndex to set. )e.Y"5My
*/ v)@EK6Nty
publicvoid setBeginIndex(int beginIndex){ Zd@'s.,J
this.beginIndex = beginIndex; LO@.aJpp
} %Kd&A*
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/** gwk$|aT@
* @return ia15r\4j)
* Returns the currentPage. <{@?c
*/ MdK!Y
publicint getCurrentPage(){ .J' 8d"+
return currentPage; 4?XX_=+F|
} c^P8)gPf
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/** FUzIuz 6
* @param currentPage &fA`Od6l"
* The currentPage to set. Lv@JfN"O
*/ xB{0lI
publicvoid setCurrentPage(int currentPage){ }OO(uC2
this.currentPage = currentPage; }J .f
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} a,o)i8G9R<
nd
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/**
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* @return LLv~yS O
* Returns the everyPage. :kSA^w8
*/ D+{h@^C9Z
publicint getEveryPage(){ ?&Si P-G
return everyPage; MfUG@
} xkR--/f
"-xm+7
/** r{qM!(T
* @param everyPage SeAokz>
* The everyPage to set. uEQH6~\{Nl
*/ ey<u
publicvoid setEveryPage(int everyPage){ 6Uq@v8mh
this.everyPage = everyPage; 6'W79
} ~rEU83
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/** log{jF
* @return .>>@q!!s!
* Returns the hasNextPage. ^7v}wpwX\
*/ Z"#ysC
publicboolean getHasNextPage(){ tr"iluwGc
return hasNextPage; >XP]NY}Po[
} i' J.c4
kRNr`yfN
/** 1\q(xka{
* @param hasNextPage Sr~zN:wn
* The hasNextPage to set. (8o~ XL
*/ B1m@
publicvoid setHasNextPage(boolean hasNextPage){ \~:Kp
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this.hasNextPage = hasNextPage; 3:jKuOX
} A<^IG+Q,B7
Acr\2!))
/** dA>t
* @return e:{v.C0ez
* Returns the hasPrePage. .$)'7
*/ #C,M8~Q7
publicboolean getHasPrePage(){ 4xhV
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return hasPrePage; )hj77~{+
} ,(Fo%.j
NylN-X7[#
/** /s& xI
* @param hasPrePage {U(-cdU{e`
* The hasPrePage to set. @uz&]~+`
*/ 3 D,PbAd
publicvoid setHasPrePage(boolean hasPrePage){ J]i=SX+ 9
this.hasPrePage = hasPrePage; cv;&ff2%?
} 4]nU%`Z1w
@B5@3zYs
/** [P8Y
* @return Returns the totalPage. +Y(cs&V*
* t3u"2B7oG
*/ bO1J#bcZ
publicint getTotalPage(){ raY5 nc{
return totalPage; S$\lM<M
} 0trVmWQ8
w=d#y
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/** 8lI#D)}
* @param totalPage mk_cub@
* The totalPage to set. DbJ:KQ!*
*/ 1g9Qvz3
publicvoid setTotalPage(int totalPage){ X!&DKE
this.totalPage = totalPage; M_+&XLnzsJ
} !y$Hr[v
{%.
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} <`5>;Xn=
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 #)q}Jw4]j
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个PageUtil,负责对Page对象进行构造: ~1wAk0G`n
java代码: AuHOdiJ
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/*Created on 2005-4-14*/ 5+rYk|*D+k
package org.flyware.util.page; 5tHv'@
i;lzFu)G
import org.apache.commons.logging.Log; |vz<FR6
import org.apache.commons.logging.LogFactory; _IOeO
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/** <F+S }!q
* @author Joa mfFC@~|g
* #9}KC 9f
*/ QD]Vfj4+
publicclass PageUtil { >T;"bcb
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privatestaticfinal Log logger = LogFactory.getLog ['R2$z
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(PageUtil.class); 1QtT*{zm$F
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/** w7p%6m
* Use the origin page to create a new page XV1#/@H;
* @param page Jx1oK
* @param totalRecords 6[wej$u
* @return ~[Mk QJxe
*/ (ZQ{%-i?qR
publicstatic Page createPage(Page page, int ]8ua>1XS
j+]>x]c0
totalRecords){ _o~<f)E[9
return createPage(page.getEveryPage(), -en:81a#
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page.getCurrentPage(), totalRecords); OJ8W'"`L&
} 5[`!\vCiZ
\6)l(b;
/** 5fv eQI~!
* the basic page utils not including exception g[*+R9'
u91;GBY
handler \:4WbM:B
* @param everyPage %\\l/{`eW
* @param currentPage \
* @param totalRecords +`kfcA#pi
* @return page pA='(G
*/ vmAMlgZ8{<
publicstatic Page createPage(int everyPage, int `j0T[Pi
1lfkb1BM
currentPage, int totalRecords){ * gr{{c
everyPage = getEveryPage(everyPage); P[ n`X
currentPage = getCurrentPage(currentPage); 9H2^4D8
int beginIndex = getBeginIndex(everyPage, eHF#ME
d{hbgUSj
currentPage); !1C3{
int totalPage = getTotalPage(everyPage, c 6}d{B[
;WJ}zjo >
totalRecords); Wd~aSz9
boolean hasNextPage = hasNextPage(currentPage, x8.7])?w
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totalPage); ->6/L)
boolean hasPrePage = hasPrePage(currentPage); :g2?)Er-
uT8/xNB!
returnnew Page(hasPrePage, hasNextPage, i&-g 0
everyPage, totalPage, 'Z+w\0}@
currentPage, g)!B};AA
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beginIndex); _xI'p6C
} qw&Wfk\}
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privatestaticint getEveryPage(int everyPage){ Xlw&hKS
return everyPage == 0 ? 10 : everyPage; C16MzrB}(N
} <oI{:KH
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privatestaticint getCurrentPage(int currentPage){ T.<eriv
return currentPage == 0 ? 1 : currentPage; 49nZWv48"_
} bWt>tEnf
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privatestaticint getBeginIndex(int everyPage, int W tnZF]1:u
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currentPage){ Q mOG2
return(currentPage - 1) * everyPage; t] P[>{y
} ct3QtX0B
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privatestaticint getTotalPage(int everyPage, int zKe&*tZ
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totalRecords){ L^KGY<hp4
int totalPage = 0; O}MY:6Pe
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if(totalRecords % everyPage == 0) /gL(40
totalPage = totalRecords / everyPage; 8;4vr@EV
else Pqo_+fL+
totalPage = totalRecords / everyPage + 1 ; Op,Ce4A
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return totalPage; X |.'_6l.
} Id
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privatestaticboolean hasPrePage(int currentPage){ Qpndi$2H!
return currentPage == 1 ? false : true; PYkcGtVa_
} k[6@\D-
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privatestaticboolean hasNextPage(int currentPage, v/c8P\
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int totalPage){ VFT
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return currentPage == totalPage || totalPage == +&jWM-T"-
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0 ? false : true; CCDoiTu!4
} pL]C]HGv
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} WiH%URFB
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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。 :&mYz(1q
wp-5B= #:{
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 )pjd*+V
;o,t*
做法如下: LZMdW
#,[
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 3%/]y=rA
.6!IO^`[
的信息,和一个结果集List: <GF)5QB
java代码: F8 ;M++
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/*Created on 2005-6-13*/ >-r\]/^
package com.adt.bo; GxLoNVr
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import java.util.List; jZ7/p ^c5R
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import org.flyware.util.page.Page; KunK.m
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/** *ys@'Ai?
* @author Joa W:aAe%S
*/ t^&:45~Q
publicclass Result { yv9~
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private Page page; ~=Z&l
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private List content; qlIC{:E0
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/** qRJg/~_h{
* The default constructor "z69jxXo
*/ Q`7!~qV0=
public Result(){ K)]7e?:Wu
super(); %/oOM\}++
} /R''R:j
7ZET@
/** Y6`9:97
* The constructor using fields PkLRQ}
* Z9i,#/
* @param page h76#HUBr!
* @param content V3$!`T}g4
*/ uw
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public Result(Page page, List content){ Y`LZ/Tgk
this.page = page; s^^X.z ,
this.content = content; }yLdU|'W
} ci+Pg9sS
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/** ,vrdtL
* @return Returns the content. %\}|&