Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 UeU`U
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 mq+<2 S
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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 =)nJ'}x
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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 $^`@ lyr
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分页支持类: a;=IOQ
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java代码: ))4RgS$
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package com.javaeye.common.util; GrI<w.9X
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import java.util.List; dZCnQ IS
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publicclass PaginationSupport { $8`"
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publicfinalstaticint PAGESIZE = 30; 7KN+ @6!x
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privateint pageSize = PAGESIZE; {_UOS8j7
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privateList items; ,O_iSohS
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privateint totalCount; JC
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privateint[] indexes = newint[0]; ( e4#9
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privateint startIndex = 0; wY"BPl]b
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public PaginationSupport(List items, int a"^rOiXR{
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totalCount){ RcOfesW
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setPageSize(PAGESIZE); =3EjD;2
setTotalCount(totalCount); 'oF
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setItems(items); }#6~/
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setStartIndex(0); i':a|#e>
} Mb-AzGsV
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public PaginationSupport(List items, int ATjE8!gO!
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totalCount, int startIndex){ TT={>R[B
setPageSize(PAGESIZE); hG>kx8h
setTotalCount(totalCount); 3
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setItems(items); 1}~`g ED
setStartIndex(startIndex); m]Mm(7v(
} " -S@R=bi
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public PaginationSupport(List items, int ^O,r8K{1n
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totalCount, int pageSize, int startIndex){ *d9RD~Ee
setPageSize(pageSize); Z29aRi
setTotalCount(totalCount); #fb&51
setItems(items); "(Nt9K%P)
setStartIndex(startIndex); Fz' s\
} 1p8hn!V
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publicList getItems(){ (wf3HEb_
return items; j<)`|?@e(
} sfk;c#K
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publicvoid setItems(List items){ ZFs
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this.items = items; >4J(\'}m|
} xtut S
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publicint getPageSize(){ *Tr9pq%m
return pageSize; L~C:1VG5
} -_= m j
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publicvoid setPageSize(int pageSize){ )r?-_qj=
this.pageSize = pageSize; sgRWjrc/
} a%5/Oc[[
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publicint getTotalCount(){ }ld^zyL
return totalCount; ^U##9KkP
} LCW}1H:Q
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publicvoid setTotalCount(int totalCount){ HlEHk'
if(totalCount > 0){ dSe d6
this.totalCount = totalCount; Mbn;~tY>
int count = totalCount / -q\Rbb5M
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pageSize; ij1YV2v
if(totalCount % pageSize > 0) ]n3!%0]\
count++; 28vQ
indexes = newint[count]; k U0.:Gcc
for(int i = 0; i < count; i++){ 45&Rl,2
indexes = pageSize * {C0Y8:"`
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} 3-'3w ,
}else{ Jhfw$ DF
this.totalCount = 0; "C?H:8W
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} [s{[
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publicint[] getIndexes(){ /fdrf
return indexes; zO@>)@~
} Jt0U`_
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publicvoid setIndexes(int[] indexes){ PkLNIp1
this.indexes = indexes; J 5xMA-
} tq?a3
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publicint getStartIndex(){ 1 jO%\uR/
return startIndex; F)v
} )j\_*SoH
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publicvoid setStartIndex(int startIndex){ _07$TC1
if(totalCount <= 0) LR';cR;
this.startIndex = 0; #jd.i
elseif(startIndex >= totalCount) `?b'.Z_J
this.startIndex = indexes wJ7^)tTRF
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[indexes.length - 1]; @C^wV
elseif(startIndex < 0) $x,EPRNs
this.startIndex = 0; E^Q
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else{ |* ^LsuFb
this.startIndex = indexes r=~K#:66
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[startIndex / pageSize]; #Ge_3^'
} i,S1|R
} xaVn.&Wl
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publicint getNextIndex(){ BC\W`K
int nextIndex = getStartIndex() + "eqzn KT%u
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pageSize; '#=0q
if(nextIndex >= totalCount) %V+"i_{m
return getStartIndex(); :H wdXhA6
else r)OiiD"
return nextIndex; -/V(Z+dj
} [cco/=c
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publicint getPreviousIndex(){ j9l32<h7]
int previousIndex = getStartIndex() - *ra>Kl0
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pageSize; LrT EF
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if(previousIndex < 0) /|<SD.:
return0; =,h'}(z_
else [`s0 L#
return previousIndex; j--byk6PB
} a(=lQ(v/?
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} _>rM[\|X
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抽象业务类 'O\ y7"a
java代码: ^i_+ugJX
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/** jT}={[9b
* Created on 2005-7-12 MtaGv#mJ
*/ ^m&I^ \
package com.javaeye.common.business; y j#*H
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import java.io.Serializable; }z$_!)/i
import java.util.List; =&,T@5&-=
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import org.hibernate.Criteria; GBT|1c'i
import org.hibernate.HibernateException; !|UX4
import org.hibernate.Session; X^K^az&L
import org.hibernate.criterion.DetachedCriteria; /t`\b
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import org.hibernate.criterion.Projections; 'Grii,
import ge:a{L
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org.springframework.orm.hibernate3.HibernateCallback; Z\xnPhV
import yCav;ZS_
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org.springframework.orm.hibernate3.support.HibernateDaoS J"LLj*,0"
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upport; tx~,7TMS/
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import com.javaeye.common.util.PaginationSupport; NjpWK;L
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public abstract class AbstractManager extends vdC0tax
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HibernateDaoSupport { B^r?N-Z A
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privateboolean cacheQueries = false; X% j`rQk`
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privateString queryCacheRegion; "a(4])
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publicvoid setCacheQueries(boolean 1n[)({OQ
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cacheQueries){
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this.cacheQueries = cacheQueries; _:=\h5}8
} HbI{Xf[6LP
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publicvoid setQueryCacheRegion(String vt2.
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queryCacheRegion){ hTzj{}w
this.queryCacheRegion = R[j? \#
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queryCacheRegion; |-b\N6
}
} *$BUow/>
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publicvoid save(finalObject entity){ cx$h"
getHibernateTemplate().save(entity); *X/Vt$P
} j?m(l,YD|*
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publicvoid persist(finalObject entity){ xb3 G,F
getHibernateTemplate().save(entity); wbAwmOiZ
} Gd_0FF .
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publicvoid update(finalObject entity){ {VW\EOPV~
getHibernateTemplate().update(entity); L6PgWc;m
} 4KtD
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publicvoid delete(finalObject entity){ T` h%=u|D
getHibernateTemplate().delete(entity); j \jMN*dmV
} %W\NYSm
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publicObject load(finalClass entity, g;'S5w9S
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finalSerializable id){ d{JI]
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return getHibernateTemplate().load t3Gy *B
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(entity, id); 0SYJ*7lPX
} S?JCi=
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publicObject get(finalClass entity, xIm2t~io
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finalSerializable id){ X,l7>>L{g
return getHibernateTemplate().get xbhHP2F|
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(entity, id); j[:70%X
} ]rj~3du\
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publicList findAll(finalClass entity){ -@>]iBl
return getHibernateTemplate().find("from |e@1@q(a[]
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" + entity.getName()); k{;?>=FH!
} mz.,j(Ks-
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publicList findByNamedQuery(finalString I\6C0x
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namedQuery){ w:%NEa,Z
return getHibernateTemplate WuY#Kx~2
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().findByNamedQuery(namedQuery); iu=Mq|t0
} J[6/dM
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publicList findByNamedQuery(finalString query, `PtB2,?
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finalObject parameter){ & n@hD7=(
return getHibernateTemplate .jqil0#)Y"
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().findByNamedQuery(query, parameter); :j3'+%'2
} ;W5.g8
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publicList findByNamedQuery(finalString query, P?>:YY53
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finalObject[] parameters){ ]@z!r2[
return getHibernateTemplate Q3l>xh
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().findByNamedQuery(query, parameters); >x6\A7
} t=Rl`1=(K
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publicList find(finalString query){ hk5!$#^
return getHibernateTemplate().find K\Q4u4DjbJ
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(query); -FZNk}
} 1VFCK&
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publicList find(finalString query, finalObject :*
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parameter){ I/St=-;
return getHibernateTemplate().find x'}zNEXI
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(query, parameter); 5Xxdm-0
} :dbO|]Xf
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public PaginationSupport findPageByCriteria J)Yz@0#T(;
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(final DetachedCriteria detachedCriteria){ nt>3 i! l
return findPageByCriteria /!Ag/SmS!9
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); #B?lU"f8q^
} Adiw@q1&
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public PaginationSupport findPageByCriteria B=W#eu
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(final DetachedCriteria detachedCriteria, finalint
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startIndex){ |a7Kn/[`,
return findPageByCriteria ^"lEa-g&
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(detachedCriteria, PaginationSupport.PAGESIZE, E]vox~xK>
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startIndex); vD#kH1
} ~FAk4z=Ed
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public PaginationSupport findPageByCriteria NoF|j57?u'
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(final DetachedCriteria detachedCriteria, finalint EY !o#m
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pageSize, /:
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finalint startIndex){ ,\+N}F^
return(PaginationSupport) FU*q9s `
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getHibernateTemplate().execute(new HibernateCallback(){ \ 6taC
publicObject doInHibernate w#BT/6W&G
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(Session session)throws HibernateException { S/eplz;
Criteria criteria = dlZ2iDQ%
{ **W7\h
detachedCriteria.getExecutableCriteria(session); *@@dO_%6
int totalCount = "-:g.x*d
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((Integer) criteria.setProjection(Projections.rowCount h~%8p
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()).uniqueResult()).intValue(); WyB^b-QmDh
criteria.setProjection 73u97oe>1
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(null); pR2U&OA
List items = wLI1qoDM
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criteria.setFirstResult(startIndex).setMaxResults NuF?:L[
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(pageSize).list(); -e"kJd&V
PaginationSupport ps = xp^Jp
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new PaginationSupport(items, totalCount, pageSize, Y0Tw:1a
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startIndex); hc]p^/H
return ps; T_wh)B4xW
} )iC@n8f7o
}, true); m%;LJ~R
} -~J5aG[@~>
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public List findAllByCriteria(final * _usVg
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DetachedCriteria detachedCriteria){ @Wm:Rz
return(List) getHibernateTemplate NTK9`#SA
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().execute(new HibernateCallback(){ ;U a48pSv
publicObject doInHibernate ?Ec{%N%
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(Session session)throws HibernateException { k
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Criteria criteria = OM7AK
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detachedCriteria.getExecutableCriteria(session); 'F/uD1;
return criteria.list(); c%wztP;L
} jc!V|w^
}, true); %ib7)8Ki0
} z wwJyy%/
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public int getCountByCriteria(final C(>g4.-p8
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DetachedCriteria detachedCriteria){ =l]
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Integer count = (Integer) Ed_Fx'
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getHibernateTemplate().execute(new HibernateCallback(){ [T[]U
publicObject doInHibernate 5V/]7>b1
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(Session session)throws HibernateException { @0tX,Z9
Criteria criteria = i3L2N~:V
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detachedCriteria.getExecutableCriteria(session); >lJTS t5{
return eqOT@~H
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criteria.setProjection(Projections.rowCount 9R-2\D]
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()).uniqueResult(); ~`$P-^u88X
} G~_D'o<r
}, true); ,5T1QWn^f
return count.intValue(); ,E%O_:}R
} @S5HMJ2=
} *].qm
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用户在web层构造查询条件detachedCriteria,和可选的 u2fp~.'P
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 (?GW/pLK]
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PaginationSupport的实例ps。 sS4V(:3s
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ps.getItems()得到已分页好的结果集 z7P~SM
ps.getIndexes()得到分页索引的数组 Qk|+Gj
ps.getTotalCount()得到总结果数 J5<16}*
ps.getStartIndex()当前分页索引 KCp9P2kv.
ps.getNextIndex()下一页索引 $n47DW&
ps.getPreviousIndex()上一页索引 Z?&ZgaSz
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 RHbbj}B
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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 NweGK
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一下代码重构了。 P{J9#.Zq&s
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我把原本我的做法也提供出来供大家讨论吧: +o0yx U
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首先,为了实现分页查询,我封装了一个Page类: 0~[M[T\
java代码: 'V <ZmJ2
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/*Created on 2005-4-14*/ {F\P3-ub
package org.flyware.util.page; tehWGqx)
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/** $S2
/*
* @author Joa i],~tT|P
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*/ z_A\\
publicclass Page { v:9'k~4)
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/** imply if the page has previous page */ TT#V'r\
privateboolean hasPrePage; 376z~
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/** imply if the page has next page */ Tfv@oPu
privateboolean hasNextPage; &%(SkL_]
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/** the number of every page */ q @wX=
privateint everyPage; kK:Wr&X0H
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