Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 .p, VZ9
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 xhOoZ-
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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 w7o`BR
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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 RQb}t,
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分页支持类: [d8Q AO1;)
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java代码: YT
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package com.javaeye.common.util; Vh;zV Y
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import java.util.List; |7tD&9<
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publicclass PaginationSupport { !6T"J!F#
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publicfinalstaticint PAGESIZE = 30; J+J,W5t^
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privateint pageSize = PAGESIZE; Zn'tNt/
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privateList items; B-R#?Xn:!I
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privateint totalCount;
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privateint[] indexes = newint[0]; Y~-y\l;Tr
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privateint startIndex = 0;
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public PaginationSupport(List items, int 15\m.Ix
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totalCount){ #Ub_m@@4
setPageSize(PAGESIZE); Xq*^6*E-}
setTotalCount(totalCount); ~,b^f{7`!
setItems(items); s|]g@czan
setStartIndex(0); '6#G$
} sQvRupYRO
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public PaginationSupport(List items, int tcuwGs>_
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totalCount, int startIndex){ ?m
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setPageSize(PAGESIZE); _\}'5nmw\
setTotalCount(totalCount); G^~[|a4`
setItems(items); ;Y$>WKsV
setStartIndex(startIndex); 6Dlm.~G
} sjr,)|#[
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public PaginationSupport(List items, int &9p!J(C
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totalCount, int pageSize, int startIndex){ qTd[DaG#
setPageSize(pageSize); $J`O-"M
setTotalCount(totalCount); 1i y$ n
setItems(items); N+|NI?R?}
setStartIndex(startIndex); Tlsh[@Q
} jwDlz.sW!
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publicList getItems(){ ,c p2Fac
return items; k$w~JO!s
} {ez$kz
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publicvoid setItems(List items){ ;b$P*dSG}
this.items = items; ti\
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} Z/#_Swv
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publicint getPageSize(){ 8i#
return pageSize; 2ym(fk.6{
} N:1aDr;
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publicvoid setPageSize(int pageSize){ %tCv-aX4
this.pageSize = pageSize; lvs
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} U
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publicint getTotalCount(){ x84!/n^z
return totalCount; )dXa:h0RZ
} 8+zW:0"[
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publicvoid setTotalCount(int totalCount){ V]=22Cxi'~
if(totalCount > 0){ M tN>5k c
this.totalCount = totalCount; f98,2I(>`+
int count = totalCount / ;O"?6d0
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pageSize; v, $r.g;
if(totalCount % pageSize > 0) 1^~&"s U
count++; #@XBHJD\#
indexes = newint[count]; z5+Pi:1w
for(int i = 0; i < count; i++){ OxlA)$.hpu
indexes = pageSize * Q#bW"},^k
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} 7+O)AU{
}else{ (`x_MTLL
this.totalCount = 0; ,6)N.
} -9Q(3$}
} vB:\ZX4
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publicint[] getIndexes(){ #NS|9jW
return indexes; \Z-th,t
} i2F7O"f.
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publicvoid setIndexes(int[] indexes){ twT/uBQ4a
this.indexes = indexes; <_EKCk
} Z%t_1t
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publicint getStartIndex(){ })g<I+]Hf9
return startIndex; uYJS=NGNA
} &?<uR)tl
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publicvoid setStartIndex(int startIndex){ v88vr
if(totalCount <= 0) h\s/rZg=r
this.startIndex = 0; VtBC~?2U)B
elseif(startIndex >= totalCount) 5mH[|_
this.startIndex = indexes xc^@"
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[indexes.length - 1]; N5Js.j>z
elseif(startIndex < 0) S?J!.(
this.startIndex = 0; *a9cBl'_
else{ 1\}vU
this.startIndex = indexes {)YbksrJ{
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[startIndex / pageSize]; ^y+k6bE
} K-qWT7<
} o`T.Zaik,
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publicint getNextIndex(){ ?N#I2jxaD
int nextIndex = getStartIndex() + 727#7Bo
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pageSize; -amo8V;2H
if(nextIndex >= totalCount) rQ*+
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return getStartIndex(); -hd
else 4:/]Y=)x
return nextIndex; \CB^9-V3
} r,5e/X
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publicint getPreviousIndex(){ u 3WU0Z`
int previousIndex = getStartIndex() - |G j.E
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pageSize; L+t
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if(previousIndex < 0) #S>N}<>
return0; Ly=.
else pdu1 kL
return previousIndex; :;$MUOps
} _u]Z+H"
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} u>XXKlW:
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抽象业务类 O,$*`RZpx
java代码: P`tOL#UeZL
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/** kQ\GVI11?
* Created on 2005-7-12 CL<-3y*
*/ V&zeC/xSq
package com.javaeye.common.business; NlYuT+
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import java.io.Serializable; }Qo]~/
import java.util.List; @ &jR^`Y.
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import org.hibernate.Criteria; FB k7Cn!
import org.hibernate.HibernateException; [s}W47N1
import org.hibernate.Session; c |0p'EQ
import org.hibernate.criterion.DetachedCriteria; ydWr&E5
import org.hibernate.criterion.Projections; 8\J$\Edv
import \`.v8C>vG
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org.springframework.orm.hibernate3.HibernateCallback; Z~:)hwF
import ?e%*q^~Cu
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org.springframework.orm.hibernate3.support.HibernateDaoS 5;`Ot2
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upport; U|wST&rU|
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import com.javaeye.common.util.PaginationSupport; F=\
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public abstract class AbstractManager extends (-<hx~
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HibernateDaoSupport { B4 bB`r
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privateboolean cacheQueries = false; ^*jwe^
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privateString queryCacheRegion; !\ b-Ot(
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publicvoid setCacheQueries(boolean 5,xPB5pK
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cacheQueries){ %=z>kU1|
this.cacheQueries = cacheQueries; [kJ;Uxncz~
} e;v7!X
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publicvoid setQueryCacheRegion(String 0}GO$%l
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queryCacheRegion){ Av.`'.b
this.queryCacheRegion = *mV?_4!,f7
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queryCacheRegion; [XPAI["
} M._h=wX{}
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publicvoid save(finalObject entity){ I484cR2.
getHibernateTemplate().save(entity); =pzTB-G
} B<~AUf*y
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publicvoid persist(finalObject entity){ E2l"e?AN~
getHibernateTemplate().save(entity); '7' 73
} aP (~l_
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publicvoid update(finalObject entity){ h0-.9ym
getHibernateTemplate().update(entity); N[9o6Nl|a
} pPxgjX
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publicvoid delete(finalObject entity){ Dhm;K$T
getHibernateTemplate().delete(entity); .|"E:qTD
} !pfpT\i]N:
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publicObject load(finalClass entity, (]k Q9}8
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finalSerializable id){ BgN^].z&
return getHibernateTemplate().load 9~^k3!>0
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(entity, id); *QNX?8Fm_
} Sc3{Y+g
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publicObject get(finalClass entity, 3hkEjR
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finalSerializable id){ {Mo[C%
return getHibernateTemplate().get r:rPzq1
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(entity, id); EId>%0s5
} 9k4z__K e
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publicList findAll(finalClass entity){ qi^kf
return getHibernateTemplate().find("from )%9:k9
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" + entity.getName()); 3 p -SpUvp
} 2/ )~$0
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publicList findByNamedQuery(finalString 8\)4waz$
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namedQuery){ MB5V$toC
return getHibernateTemplate M~X~2`fFH
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().findByNamedQuery(namedQuery); $Q|6W &?[;
} kQ[23
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publicList findByNamedQuery(finalString query, >7?Lq<H
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finalObject parameter){ %YuFw|wO
return getHibernateTemplate wd,6/5=lh
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().findByNamedQuery(query, parameter); 7wrRIeES
} q@mZ0D-
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publicList findByNamedQuery(finalString query, ;M+~e~
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finalObject[] parameters){ 1mv5B t
return getHibernateTemplate ju.`c->k"
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().findByNamedQuery(query, parameters); H_iQR9Ak7
} UOe@R|79q
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publicList find(finalString query){ ,]@Sytky
return getHibernateTemplate().find So NgDFD
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(query); 5uM`4xkj
} O/l/$pe
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publicList find(finalString query, finalObject H'@@%nO(
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parameter){ Mf9x=K9
return getHibernateTemplate().find SR4 mbQ:
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(query, parameter); ) C#>@W
} o~x49%X<c
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public PaginationSupport findPageByCriteria BE!WCDg,
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(final DetachedCriteria detachedCriteria){ $3Sm?
return findPageByCriteria SG)|4$"
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); wWJM./y
} xn<x/e
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public PaginationSupport findPageByCriteria !imjfkG
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(final DetachedCriteria detachedCriteria, finalint ATD4%|a9h
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startIndex){ .V{y9e+
return findPageByCriteria K!tM "`a
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(detachedCriteria, PaginationSupport.PAGESIZE, X$<CIZ
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startIndex); E7U.>8C
} X<:Zx#J?i
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public PaginationSupport findPageByCriteria p v*f]Yzx
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(final DetachedCriteria detachedCriteria, finalint dJ7 !je1N*
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pageSize, U1pwk[
finalint startIndex){ #PMi6q~Z
return(PaginationSupport) K1*V \WRW5
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getHibernateTemplate().execute(new HibernateCallback(){ ^4
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publicObject doInHibernate q}p
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(Session session)throws HibernateException { bSk)GZyH\d
Criteria criteria = {xQ(xy
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detachedCriteria.getExecutableCriteria(session); bP1]:^ x@W
int totalCount = k mX:~KMb
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((Integer) criteria.setProjection(Projections.rowCount 5NhwIu^<
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()).uniqueResult()).intValue(); ft Rza
criteria.setProjection ]= 9^wS
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(null); x|A{|oFC
List items = FrQRHbp3
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criteria.setFirstResult(startIndex).setMaxResults ^r^) &]
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(pageSize).list(); 5H/D~hr&
PaginationSupport ps = =U3rOYbP;
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new PaginationSupport(items, totalCount, pageSize, ~d&W;mef-
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startIndex); ? VHOh9|AT
return ps; 4w(#`'I>
} njBK {
}, true); 5c6?$v/
} Hge0$6l
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public List findAllByCriteria(final {Nny.@P)H
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DetachedCriteria detachedCriteria){ </)HcRj'e
return(List) getHibernateTemplate fV5MI[t
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().execute(new HibernateCallback(){ Tj,1]_`=V$
publicObject doInHibernate 6,Y<1b*|Vo
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(Session session)throws HibernateException { #@K
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Criteria criteria = ^z}$'<D9
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detachedCriteria.getExecutableCriteria(session); <%:,{u6
return criteria.list(); =.8fES
} VL| q`n
}, true); I2<5#|CXpZ
} Eh/Z4pzT
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public int getCountByCriteria(final }J|Pd3Q Sf
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DetachedCriteria detachedCriteria){ SH/^qDT'
Integer count = (Integer) %<[U\TL`
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getHibernateTemplate().execute(new HibernateCallback(){ HMPb%'U~
publicObject doInHibernate KkD&|&!Q7u
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(Session session)throws HibernateException { rM{V>s:N
Criteria criteria = "=3bL>\<
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detachedCriteria.getExecutableCriteria(session); |%c"Avc
return E7>D:BQ\2
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criteria.setProjection(Projections.rowCount Ue2%w/Yo
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()).uniqueResult(); ?5jq)xd2
} 9@yi
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}, true); b,):&M~p
return count.intValue(); `T(T]^C98
} d@e2+3<
} *dmS'/
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用户在web层构造查询条件detachedCriteria,和可选的 ]x:>!y
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 Ic')L*i7O
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PaginationSupport的实例ps。 1%`Nu ]D
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ps.getItems()得到已分页好的结果集 qEajT"?
ps.getIndexes()得到分页索引的数组 =]m,7 v Rq
ps.getTotalCount()得到总结果数 s5
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ps.getStartIndex()当前分页索引 E)z=85;_p
ps.getNextIndex()下一页索引 w~wg[d
ps.getPreviousIndex()上一页索引 Vh'H =J
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 iph}!3f
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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 .)Zs:50l
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一下代码重构了。 CWa~~h<r-
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我把原本我的做法也提供出来供大家讨论吧: b!oj3|9
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首先,为了实现分页查询,我封装了一个Page类: \qz! v
java代码: o1Nfn'!3/>
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/*Created on 2005-4-14*/ Wn-'iD+9<
package org.flyware.util.page; s`gfz}/
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/** D`R~d;U~
* @author Joa \>[k0<
* lKG' KR.
*/ XNJ3.w:R
publicclass Page { Y49&EQ
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/** imply if the page has previous page */ 3?e~J"WXC5
privateboolean hasPrePage; nrg$V>pD
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/** imply if the page has next page */ x;{Hd;<YF
privateboolean hasNextPage; pp@O6
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/** the number of every page */ a:Nf+t
privateint everyPage; +w/B3b
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/** the total page number */ 4W#DLip9
privateint totalPage; 1gQ_76Yck
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/** the number of current page */ JOH\K0=e
privateint currentPage; +Fb+dU
% {-r'Yi%
/** the begin index of the records by the current S)?N6sz%
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query */
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privateint beginIndex; f,x;t-o+R
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/** The default constructor */ !jvl"+_FV
public Page(){ UA|\D]xe
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} ]
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/** construct the page by everyPage v*OV\h.
* @param everyPage ..zX
* */ =3ovaP
public Page(int everyPage){ 33; '6/
this.everyPage = everyPage; f `D(V-4
} 4/%Y@Z5
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/** The whole constructor */ \d*ts(/a*
public Page(boolean hasPrePage, boolean hasNextPage, Gu@C*.jj!
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int everyPage, int totalPage, ':3[?d1Es
int currentPage, int beginIndex){ M4D @G
this.hasPrePage = hasPrePage; +u&[ j/
this.hasNextPage = hasNextPage; :d pwr9)
this.everyPage = everyPage; @]]&^ 7
this.totalPage = totalPage; 684|Uuf7
this.currentPage = currentPage; plp-[eKcD
this.beginIndex = beginIndex; :t<