Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Aba6/
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 H[-zQ#I9
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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 guwnYS
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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 q".l:T%|C}
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分页支持类: F!fxA#
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java代码: QQC0uta`
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package com.javaeye.common.util; y99G 3t
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import java.util.List; :$P <e~z'
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publicclass PaginationSupport { ig?]kZ
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publicfinalstaticint PAGESIZE = 30; ,
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privateint pageSize = PAGESIZE; -Ep-v4}
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privateList items; =3 -G
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privateint totalCount; DbOWnXV"o
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privateint[] indexes = newint[0]; hTg%T#m
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privateint startIndex = 0; *a$z!Ma3h
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public PaginationSupport(List items, int @8/-^Rh*
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totalCount){ p&ZD1qa
setPageSize(PAGESIZE); u 4)i7
setTotalCount(totalCount); Gc
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setItems(items); |@d7o]eM|
setStartIndex(0); 1lMU('r%
} bLf }U9
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public PaginationSupport(List items, int Y|1kE;
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totalCount, int startIndex){ tSQ>P -O
setPageSize(PAGESIZE); n{UB^-}5
setTotalCount(totalCount); nq_sbli
setItems(items); (wbG0lu
setStartIndex(startIndex); {){i
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} *K0CUir|
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public PaginationSupport(List items, int %2qvK}
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totalCount, int pageSize, int startIndex){ nP_ s+k
setPageSize(pageSize); Y{2\==~
setTotalCount(totalCount); ^*Rr x
setItems(items); Vl'|l)b4W
setStartIndex(startIndex); t|%iW%m4
} o1kLT@VCl
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publicList getItems(){ 9~u1fk{
return items; ~":?})
} %]
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publicvoid setItems(List items){ /<y-pFTg
this.items = items; uZW1
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} -*tP_=- Dg
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publicint getPageSize(){ 2:2rwH }e
return pageSize; mJWl#3
} 5v>(xl
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publicvoid setPageSize(int pageSize){ XlB`Z81j
this.pageSize = pageSize; 9-)oA+$
} @\[&_DZ
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publicint getTotalCount(){ ~M43#E[oOF
return totalCount; Po=)jkW
} b~v
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publicvoid setTotalCount(int totalCount){ }U+gJkY2
if(totalCount > 0){ [)9bR1wh
this.totalCount = totalCount; K+Ehj(eF
int count = totalCount / l=bB,7gL
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pageSize; m.S@ e8kS
if(totalCount % pageSize > 0) 'du:Bxl`d4
count++; '{U56^b]
indexes = newint[count]; t~X wF(";
for(int i = 0; i < count; i++){ U3%!#E{
indexes = pageSize * TZPWMCN4
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} $5cLhi"`
}else{ ZYrd;9zB
this.totalCount = 0; fm:/}7s
} Lj({
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} Bn47O~
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publicint[] getIndexes(){ :uhvDYp(-
return indexes; o&gcFOM22
} 8R8J./i.K
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publicvoid setIndexes(int[] indexes){ %=\h=\wt
this.indexes = indexes; t`H^!
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} BI,K?D&W-
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publicint getStartIndex(){ <F>\Vl:
return startIndex; kzgHp,;R{
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publicvoid setStartIndex(int startIndex){ k`2 K?9\
if(totalCount <= 0) a5z.c_7r
this.startIndex = 0; @+B
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elseif(startIndex >= totalCount) +6uun
this.startIndex = indexes hG&RGN_<6+
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[indexes.length - 1]; 3 +BPqhzf
elseif(startIndex < 0) 26.iFt/:
this.startIndex = 0; mkrvWZjZX
else{ / D#vs9S
this.startIndex = indexes _(J- MCY\
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[startIndex / pageSize]; 4
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} noh3mi
} } +i
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publicint getNextIndex(){ A{mbL2AxwC
int nextIndex = getStartIndex() + l
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pageSize; qPH]DabpI
if(nextIndex >= totalCount) `S{< $:D
return getStartIndex(); :[|`&_D9J
else ;oWh Tj`
return nextIndex; ^X"G~#v=q
} g4RkkoZ>)
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publicint getPreviousIndex(){ 5j{o0&=_$
int previousIndex = getStartIndex() - E'JVf%)
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pageSize; i
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if(previousIndex < 0) v?fB:[dG
return0; P}DrUND
else ^ylJ_lN&=1
return previousIndex; ~9h6"0K!
} nU)}!` E
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抽象业务类 3(E"$Se,f
java代码: P]]9Sqo7
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/** +g7Iu! cA
* Created on 2005-7-12 @hQ+pG@s
*/ _Dwn@{[(8
package com.javaeye.common.business; PPPRO.y
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import java.io.Serializable; f!xIMIl)+
import java.util.List; f.V0uBDN
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import org.hibernate.Criteria; D@>P%k$$s>
import org.hibernate.HibernateException; vyN=X]p
import org.hibernate.Session; wf6ZzG:
import org.hibernate.criterion.DetachedCriteria; P.&,nFIg3
import org.hibernate.criterion.Projections; g3e\'B'
import Uc<B)7{'
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org.springframework.orm.hibernate3.HibernateCallback; h9>~?1$lz
import Vy-H3BR
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org.springframework.orm.hibernate3.support.HibernateDaoS 5p
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upport; 2EQ:mjxk
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import com.javaeye.common.util.PaginationSupport; lv&<kYWY
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public abstract class AbstractManager extends '`/1?,=
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HibernateDaoSupport { A~h.,<+"
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privateboolean cacheQueries = false; hh
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privateString queryCacheRegion; UKMrR9[x*
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publicvoid setCacheQueries(boolean 9t7_7{Q+;
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cacheQueries){ ldI;DoE#U1
this.cacheQueries = cacheQueries; ?Xh=rx_
} j=
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publicvoid setQueryCacheRegion(String NrNbNFfo
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queryCacheRegion){ A;Xn#t ,(K
this.queryCacheRegion = #*}4=
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queryCacheRegion; &"K74
} <CzH'!FJN
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publicvoid save(finalObject entity){ #^yw!~:{
getHibernateTemplate().save(entity); Tj<W4+p{
} P]j{JL/g&
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publicvoid persist(finalObject entity){ vZhN%
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getHibernateTemplate().save(entity); cl^wLC'o
} My,ki:V?g6
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publicvoid update(finalObject entity){ ?9OiF-:n
getHibernateTemplate().update(entity); 9~
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} 7W5FHZd'
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publicvoid delete(finalObject entity){ z<sf}6q
getHibernateTemplate().delete(entity); #wk'&XsC#z
} F1w~f
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publicObject load(finalClass entity, `GqS.O}C
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finalSerializable id){ 4g$mz:vo
return getHibernateTemplate().load ]y2(ZTNTs
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(entity, id); HZkC3$
} 4F??9o8 }
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publicObject get(finalClass entity, ) e;)9~
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finalSerializable id){ ,l.O @
return getHibernateTemplate().get 9"I/jd0B
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(entity, id); esLPJx
} b U-Cd
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publicList findAll(finalClass entity){ WG1UvPK
return getHibernateTemplate().find("from zY bSv~)
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" + entity.getName()); fY}e.lD
} wHx1CXC
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publicList findByNamedQuery(finalString _$9<N5F.,o
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namedQuery){ >(<OhS(
return getHibernateTemplate oi::/W|A+
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().findByNamedQuery(namedQuery); T]Vh]|_s
} HZ>Xm6DnC5
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publicList findByNamedQuery(finalString query, ;E,%\<
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finalObject parameter){ c}U&!R2p{
return getHibernateTemplate (fUXJ$
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().findByNamedQuery(query, parameter); ^;Nu\c
} >/. -N
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publicList findByNamedQuery(finalString query, 9mEC|(m*WK
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finalObject[] parameters){ 8*V3g_z
return getHibernateTemplate &y;('w
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().findByNamedQuery(query, parameters); Sl/[9-a)
} +`r;3kH ..
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publicList find(finalString query){ :tu6'X\k
return getHibernateTemplate().find %?' jyK
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(query); po}Jwx!
} ULIbVy7Y
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publicList find(finalString query, finalObject V2W)%c'
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parameter){ : P>Wd3m
return getHibernateTemplate().find U]riBlg>
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(query, parameter); ^w5`YI4<
} gI~Ru8
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public PaginationSupport findPageByCriteria >V2Tr$m j
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(final DetachedCriteria detachedCriteria){ `PXSQf
return findPageByCriteria FX`SaY>D
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); dE=4tqv-r
} IGeXj%e
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public PaginationSupport findPageByCriteria Q|q.~x<RQ
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(final DetachedCriteria detachedCriteria, finalint v_3r8My-
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startIndex){ DF|(CQs9
return findPageByCriteria i1e|UR-wl
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(detachedCriteria, PaginationSupport.PAGESIZE, |j($2.
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startIndex); tn&~~G~#
} 'B ocMjRA
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public PaginationSupport findPageByCriteria Q>]FO
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(final DetachedCriteria detachedCriteria, finalint [LDsn]{
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pageSize, }wJ-*By{+
finalint startIndex){ bBA
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return(PaginationSupport) $a|C/s+}7>
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getHibernateTemplate().execute(new HibernateCallback(){ 5]D"y Ay81
publicObject doInHibernate w7aC=B/{?i
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(Session session)throws HibernateException { Khp`KPxz%
Criteria criteria = w-9M{Es+j
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detachedCriteria.getExecutableCriteria(session); &o@IMbJ8
int totalCount = 8D7=]
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((Integer) criteria.setProjection(Projections.rowCount S?TyC";!
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()).uniqueResult()).intValue();
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criteria.setProjection d/oxRzk'L
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(null); Z<+Ipj&
List items = yv1Z*wTpO
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criteria.setFirstResult(startIndex).setMaxResults [AgS@^"sf5
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(pageSize).list(); X633.]+
PaginationSupport ps = :rr;9nMR[
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new PaginationSupport(items, totalCount, pageSize, o ;nw;]oR
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startIndex); ^0"W/
return ps; ^=kUNyY
} n
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}, true); ;#c=0*.
} 9[#9cv
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public List findAllByCriteria(final %-u Ra\
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DetachedCriteria detachedCriteria){ 7ip$#pzo
return(List) getHibernateTemplate gr]:u4}
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().execute(new HibernateCallback(){ ibe#Y
publicObject doInHibernate c*iZ6j"iI
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(Session session)throws HibernateException { EtVRnI@
Criteria criteria = =2-!ay:
! n@*6
detachedCriteria.getExecutableCriteria(session); Ih_2")d
return criteria.list(); ZY NHVR
} RE*;_DF
}, true); 7Q_AZR4
} Zp:(U3%
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public int getCountByCriteria(final 8 cN[t.S
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DetachedCriteria detachedCriteria){ ?f}lYQzM
Integer count = (Integer) tXZE@JyuC
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getHibernateTemplate().execute(new HibernateCallback(){ bU3e*Er
publicObject doInHibernate AC`4n|,zJ;
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(Session session)throws HibernateException { ="yN4+0-p
Criteria criteria = ?<_yW#x6
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detachedCriteria.getExecutableCriteria(session); tXlo27J
return w4 R!aWLd
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criteria.setProjection(Projections.rowCount vUlGE
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()).uniqueResult(); iR_j
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} d<x7* OW)
}, true); l+%2kR
return count.intValue(); c,wYXnJ_t
} +`y{r^xD
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用户在web层构造查询条件detachedCriteria,和可选的 c/K:`XP~
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 Jf#Ika&px
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PaginationSupport的实例ps。 !z EW)
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ps.getItems()得到已分页好的结果集 O~wZU Zf
ps.getIndexes()得到分页索引的数组 F!N D
ps.getTotalCount()得到总结果数 -^R6U~
ps.getStartIndex()当前分页索引 /Qa'\X,f3
ps.getNextIndex()下一页索引 { :^;byd
ps.getPreviousIndex()上一页索引 qdss(LZ
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 xJ&E2Bf
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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 -@I+IKz
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一下代码重构了。 Lm!/iseGv
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我把原本我的做法也提供出来供大家讨论吧: ' F,.y6QU
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首先,为了实现分页查询,我封装了一个Page类: ?3duW$`
java代码: oJ:\8>)9
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/*Created on 2005-4-14*/ \me'B {aa
package org.flyware.util.page; GR%h3HO2&
qV7F=1k]
/** 5s7C;+
* @author Joa ?q*,,+'0
* *XCgl*% *
*/ [& d"Z2gK
publicclass Page { q{c/TRp7
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/** imply if the page has previous page */ i&di}x
privateboolean hasPrePage; 3g{T+c*
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/** imply if the page has next page */ :TZ</3Sw
privateboolean hasNextPage; +YX*.dW
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/** the number of every page */ n N_Ylw
privateint everyPage; ^&|KuI+u
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/** the total page number */ s?9$o
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privateint totalPage; ir?Y>
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/** the number of current page */ (c\i .z
privateint currentPage; d1{%z\u
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/** the begin index of the records by the current 8Buus
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query */ .S6u{B
privateint beginIndex; Iq%
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/** The default constructor */ r.vezsH
public Page(){ +8zCol?j
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} gwQk
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/** construct the page by everyPage D:I6nSoC
* @param everyPage RHj<t");
* */ Od?b(bE.]
public Page(int everyPage){ #^zUaPV 7r
this.everyPage = everyPage; rv26vnJy"
} k0>]7t$L
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/** The whole constructor */ MVYf-'\^
public Page(boolean hasPrePage, boolean hasNextPage, a'prlXr\4
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int everyPage, int totalPage, ,>vI|p,/G*
int currentPage, int beginIndex){ 47
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this.hasPrePage = hasPrePage; y7LT;`A
this.hasNextPage = hasNextPage; 5a^b{=#Y
this.everyPage = everyPage; .G/2CVMj
this.totalPage = totalPage; ><