Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 [)p>pA2GZj
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 jTz~
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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 U{.y X7
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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 .37Jrh0Iv
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分页支持类: 6M_,4>
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java代码: 5@@ilvwzz
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package com.javaeye.common.util; HO
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import java.util.List; uY|-: =
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publicclass PaginationSupport { ^NiS7 )FX
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publicfinalstaticint PAGESIZE = 30; /jv4#9
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privateint pageSize = PAGESIZE; a{7'qmN1
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privateList items; Vq<\ixRi
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privateint totalCount; 6` @4i'.
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privateint[] indexes = newint[0]; =L&}&pT
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privateint startIndex = 0; +(3U_]Lu
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public PaginationSupport(List items, int +&h<:/ V
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totalCount){ 8!(09gW'>
setPageSize(PAGESIZE); -9z!fCu3
setTotalCount(totalCount); _B5vh(.
setItems(items); m<uBRI*I
setStartIndex(0); U0X? ~ 1
} fC$(l@O?
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public PaginationSupport(List items, int wz=c#}0dB
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totalCount, int startIndex){ V*w~Sr%
setPageSize(PAGESIZE); `suEN@^
setTotalCount(totalCount); TO~Z6NA0
setItems(items); lo:{T_ay
setStartIndex(startIndex); Doj>Irj?7
} (TJ )Y7E
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public PaginationSupport(List items, int X1PXX!]lo[
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totalCount, int pageSize, int startIndex){ s/0S]P]}f
setPageSize(pageSize); (!B1}5"
setTotalCount(totalCount); r0fxEYze&
setItems(items); E\Et,l#|LY
setStartIndex(startIndex); 9#X"m,SB
} [uD G;We=
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publicList getItems(){ tlJ@@v&=
return items; 2jiH&'@
}
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publicvoid setItems(List items){ [DzZ:8
this.items = items; M4`.[P4
} +<1MY'>y
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publicint getPageSize(){ 1r LK1X
return pageSize; |`,AAa
} O4.`N?Xq
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publicvoid setPageSize(int pageSize){ g#/"3P2H
this.pageSize = pageSize; o!-kwtw`l
} fS#I?!*}
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publicint getTotalCount(){ j}fu|-
return totalCount; 9 m`VIB
} <*F!A' w2o
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publicvoid setTotalCount(int totalCount){ aoP=7d|K/
if(totalCount > 0){ {GP#/5$=
this.totalCount = totalCount; ,z0~VS:g 8
int count = totalCount / r(6$.zx
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pageSize; B9h'}460H
if(totalCount % pageSize > 0) BDiN*.w5
count++; D(&XmC[\Y
indexes = newint[count]; |Jpi|'
for(int i = 0; i < count; i++){ ')#!M\1,HQ
indexes = pageSize * @D@_PA)e(
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} !<#,M9
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}else{ E,p4R%:$@1
this.totalCount = 0; {
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} I:Q3r"1
} =Hf`yH\#
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publicint[] getIndexes(){ N,ysv/zq7
return indexes; wx[Y2lUh6
} Zv&<r+<g
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publicvoid setIndexes(int[] indexes){ _A]=45cn~
this.indexes = indexes; gO%oA} !i
} m[8?d~
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publicint getStartIndex(){ yp
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return startIndex; i!u:]14>
} ,LftQ1*;
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publicvoid setStartIndex(int startIndex){ ?w5>Z/V
if(totalCount <= 0) @tzL4hy%^j
this.startIndex = 0; Cr>YpWm
elseif(startIndex >= totalCount)
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this.startIndex = indexes ]gjB%R[.m
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[indexes.length - 1]; hA:RVeS{
elseif(startIndex < 0) ly( LMr
this.startIndex = 0; w
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else{ 4D=^24f`0
this.startIndex = indexes !Y^3% B%
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[startIndex / pageSize]; _MxKfah'
} khe.+Qfgj
} W!B\VB
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publicint getNextIndex(){ @5tGI U;1
int nextIndex = getStartIndex() + \w@V7~vA
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pageSize; f=paa/k0
if(nextIndex >= totalCount) N'n\_ x
return getStartIndex(); eJ+@<+vr;x
else Mem1X rBH
return nextIndex; Ju"K"
} B2T=O %
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publicint getPreviousIndex(){ u#)ARCx ,w
int previousIndex = getStartIndex() - N:~CN1
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pageSize; yt[*4gF4
if(previousIndex < 0) <*[D30<
return0; ^u-;VoK
else "Ta"5XW
return previousIndex; <_3OiU=w
} T
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} nA#N ,^Rr
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抽象业务类 |m F=X*
java代码: 6H^=\
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/** /Y0oA3am
* Created on 2005-7-12 -(JBgM"
*/ kK_9I (7c
package com.javaeye.common.business; UH`cWV Lpr
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import java.io.Serializable; g).IF.
import java.util.List; Lk2;\ D>
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import org.hibernate.Criteria; 4,.[B7irR
import org.hibernate.HibernateException; ~nRbb;M
import org.hibernate.Session; L "5;<
import org.hibernate.criterion.DetachedCriteria; tJII-\3"
import org.hibernate.criterion.Projections; =4#p|OZP
import (d*~Qpi{7
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org.springframework.orm.hibernate3.HibernateCallback; O&evv8 6L
import vVf%wei^#
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org.springframework.orm.hibernate3.support.HibernateDaoS cCv@fks
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upport; s[Whg!2~
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import com.javaeye.common.util.PaginationSupport; irF+(&q]jh
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public abstract class AbstractManager extends +wGFJLHJ
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HibernateDaoSupport { NeR1}W
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privateboolean cacheQueries = false; ~;vt{pk
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privateString queryCacheRegion; {sF;R.P&r
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publicvoid setCacheQueries(boolean qo7jrY5G
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cacheQueries){ < Y)A ez
this.cacheQueries = cacheQueries; ~F[JupU
} wUKt$_]``
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publicvoid setQueryCacheRegion(String oT i$@q
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queryCacheRegion){ ]23+ d/
this.queryCacheRegion = YP73
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queryCacheRegion; h@ @q:I=
} tZygTvK/S
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publicvoid save(finalObject entity){ tN0?
getHibernateTemplate().save(entity); o'=i$Eb
} <~
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publicvoid persist(finalObject entity){ Nt~G
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getHibernateTemplate().save(entity); rw%OA4>
} /X;!
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publicvoid update(finalObject entity){ mw*KLMo42
getHibernateTemplate().update(entity); =U}!+ 8f
} { {+:Vy
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publicvoid delete(finalObject entity){ !RwMUnp
getHibernateTemplate().delete(entity); Q+p9^_r
} G$t:#2
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publicObject load(finalClass entity, D<lV WP
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finalSerializable id){ wUH:l
return getHibernateTemplate().load ;-VXp80J
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(entity, id); %";ap8J04F
} e7n`fEpO
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publicObject get(finalClass entity, v,c;dlg_
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finalSerializable id){ 7W=s.Gy7G\
return getHibernateTemplate().get R]N"P:wf@
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(entity, id); F@1Eg
} ;eC8|
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publicList findAll(finalClass entity){ Ur(< ]
return getHibernateTemplate().find("from +K48c,gt?
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" + entity.getName()); `FByME
} sM@1Qyv&0
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publicList findByNamedQuery(finalString Bs\&'=l
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namedQuery){ .x_F4 #Ka
return getHibernateTemplate z`!f'I--!
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().findByNamedQuery(namedQuery); nxs'qX(D
} yK w.69.
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publicList findByNamedQuery(finalString query, Z8o8>C\d9/
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finalObject parameter){
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return getHibernateTemplate Q$x
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().findByNamedQuery(query, parameter); 3u4P
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} k.wm{d]J
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publicList findByNamedQuery(finalString query, ZX0!BS
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finalObject[] parameters){ AX6l=jFZx
return getHibernateTemplate K*N8Vpz(
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().findByNamedQuery(query, parameters); /;`-[
} ]>,Lw=_[_
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publicList find(finalString query){ v8\pOI}c
return getHibernateTemplate().find v(^;%
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(query); &+df@U6i
} f&?
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publicList find(finalString query, finalObject 3 H`ES_JL
)
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parameter){ 9O-*iK
return getHibernateTemplate().find h`:B8+k
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(query, parameter); TJs ~}&L
} W=2#Q2)
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public PaginationSupport findPageByCriteria $aj:\A0f
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(final DetachedCriteria detachedCriteria){ i"#zb&~nF
return findPageByCriteria >7 qZ\#
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); zI'c 'X1,
} Y|aaZ|+
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public PaginationSupport findPageByCriteria :@J.!dokF
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(final DetachedCriteria detachedCriteria, finalint )`}4rD^b
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startIndex){ <ugy-vSv
return findPageByCriteria 1p(9hVA
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(detachedCriteria, PaginationSupport.PAGESIZE, #A^(1
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startIndex); rG{,8*
} $i$Z+-W4'
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public PaginationSupport findPageByCriteria $%"~.L4
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(final DetachedCriteria detachedCriteria, finalint &Tk@2<5=
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pageSize, xd^9R<
finalint startIndex){ N@R?<a
return(PaginationSupport) d.p%jVO)"
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getHibernateTemplate().execute(new HibernateCallback(){ xU'% 6/G
publicObject doInHibernate Vn6]h|vm
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(Session session)throws HibernateException { sF p% T4j
Criteria criteria = {Zf 9}
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detachedCriteria.getExecutableCriteria(session); }RZN3U=
int totalCount = DQ= /Jr~
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((Integer) criteria.setProjection(Projections.rowCount zE]h]$oi
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()).uniqueResult()).intValue();
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criteria.setProjection Ypw:Vp
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(null); p-B
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List items = /t_AiM,(
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criteria.setFirstResult(startIndex).setMaxResults 3Hkb)Wu
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(pageSize).list(); *hkNJ
PaginationSupport ps = GqD_6cdh
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new PaginationSupport(items, totalCount, pageSize,
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startIndex); p/'09FY+ U
return ps; G*rlU
} 4i(?5p>f
}, true); 9NausE40
} ZGQz@H5
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public List findAllByCriteria(final GaLQ/V2R
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DetachedCriteria detachedCriteria){ rjL4t^rT
return(List) getHibernateTemplate hbE~.[Y2r
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().execute(new HibernateCallback(){ YH'j"|{
publicObject doInHibernate @;h$!w<
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(Session session)throws HibernateException { #]lK! :
Criteria criteria = 6Wc'5t3
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detachedCriteria.getExecutableCriteria(session); eX <@qa4<
return criteria.list(); ?7R&=B1g
} 4'`y5E
}, true); z*G(AcS)
} e6uVUzP4
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public int getCountByCriteria(final ==Bxv:6
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DetachedCriteria detachedCriteria){ w4j,t
Integer count = (Integer) P2sM3C
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getHibernateTemplate().execute(new HibernateCallback(){ s)j3+@:#
publicObject doInHibernate [.c'22R6
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(Session session)throws HibernateException { J|:Zs1.<d
Criteria criteria = %2<u>=6byG
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detachedCriteria.getExecutableCriteria(session); Ygfv?
return @&GfCg5Cb
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criteria.setProjection(Projections.rowCount wvlM(
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()).uniqueResult(); j2Uu8.8d
} s[#ww
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}, true); IHvrx:7
return count.intValue(); ^ 9 FRI9?
} tW}At
} 6$LQO),,
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用户在web层构造查询条件detachedCriteria,和可选的 /'Q2TLy=
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 &@/25Y2
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PaginationSupport的实例ps。 _"G./X
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ps.getItems()得到已分页好的结果集 iuS*Vw
ps.getIndexes()得到分页索引的数组 {`=k$1
ps.getTotalCount()得到总结果数 D=:O^<
ps.getStartIndex()当前分页索引 NH0uK
ps.getNextIndex()下一页索引 !nt[J$.z^
ps.getPreviousIndex()上一页索引 B8.uzX'p
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ^F:Bj&0v[
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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 j6DI$tV~
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一下代码重构了。 6gTc)rhRT
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我把原本我的做法也提供出来供大家讨论吧: j-TRa,4bN
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首先,为了实现分页查询,我封装了一个Page类: oxXCf%!
java代码: (fcJp)D
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/*Created on 2005-4-14*/ _BHEK
package org.flyware.util.page; P9jPdls
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/** 4rrR;V"}
* @author Joa qA5 Ug
* ciGJtD&P
*/ ,v_NrX=f?
publicclass Page { M3Oqto<8"
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/** imply if the page has previous page */ O#?@'1
privateboolean hasPrePage; !Z<=PdI1Ys
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/** imply if the page has next page */ +l<l3uBNS
privateboolean hasNextPage; 5&TH\2u
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/** the number of every page */ 52t6_!y+V
privateint everyPage; 20cEE>
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/** the total page number */ +0g L!r
privateint totalPage; ^]MLEr!S
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/** the number of current page */ /X%+z5
privateint currentPage; y3OF+;E
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/** the begin index of the records by the current odW K\e
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query */ n}/4em?
privateint beginIndex; IR|#]en
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/** The default constructor */ :B:6ezDF6
public Page(){ 2]=`^rC*
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} 1P?|.W_^1
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/** construct the page by everyPage u(i=-PN_<
* @param everyPage {r'+icvLX
* */ F}?4h Dt
public Page(int everyPage){ ?!y<%&U
this.everyPage = everyPage; hlmeT9v{
} ($-m}UF\/
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/** The whole constructor */ )6(|A$~C+
public Page(boolean hasPrePage, boolean hasNextPage, &%m%b5
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int everyPage, int totalPage, :0Z\-7iK
int currentPage, int beginIndex){ < n/ 2
this.hasPrePage = hasPrePage; </2 aQn
this.hasNextPage = hasNextPage; Ub/ZzAwq
this.everyPage = everyPage; 1!NrndJ I
this.totalPage = totalPage; 3S"
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this.currentPage = currentPage; (eSsx/
this.beginIndex = beginIndex; 8N \<o7t%
} ,Oe:SZJ>
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/** +lxjuEiae
* @return tAsap}(
* Returns the beginIndex. SDB \6[D
*/ Zz"8
publicint getBeginIndex(){ 2M=h:::W
return beginIndex; xpc{#/Nk
} U~USwUzgY
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