Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ^z3-$98=A
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 xd8UdQ,lt
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 ByeyUw
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 )NZ6!3[@
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分页支持类: VP=(",`
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java代码: |jm|/{lc
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package com.javaeye.common.util; 13Ga #
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import java.util.List; hb9X<N+p
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publicclass PaginationSupport { 1(M0C[P
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publicfinalstaticint PAGESIZE = 30; L7mN&Xr
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privateint pageSize = PAGESIZE; 8^=g$;g
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privateList items; X"b4U\A
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privateint totalCount; wo7.y["$
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privateint[] indexes = newint[0]; zvL&V
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privateint startIndex = 0; c\UVMyE
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public PaginationSupport(List items, int @Fqh]1t
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totalCount){ nL@
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setPageSize(PAGESIZE); hC<X\yxe
setTotalCount(totalCount); 'P}"ZHW
setItems(items); FCQoz"M
setStartIndex(0); W^0F(9~!(
} m_~
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public PaginationSupport(List items, int l?(nkg["nY
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totalCount, int startIndex){ P]T(I/\g
setPageSize(PAGESIZE); X`]-)(UX
setTotalCount(totalCount); FQB)rxP
setItems(items); BDxrS q,H
setStartIndex(startIndex); :gY$/1SYD
} C<fWDLwYqV
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public PaginationSupport(List items, int F1R91V|
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totalCount, int pageSize, int startIndex){ k);z}`7
setPageSize(pageSize);
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setTotalCount(totalCount); wq_c^Ioy
setItems(items); &T]+g8 ''
setStartIndex(startIndex); (p`'Okw
} C=@BkneQ
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publicList getItems(){ shxr^
return items; KSVIX!EsX
} (}O)pqZ>
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publicvoid setItems(List items){ 3/:O8H
this.items = items; 0~A<AF*t
} UA{sUj+?
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publicint getPageSize(){ >OE.6)'Rm
return pageSize; qLKyr@\'
}
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publicvoid setPageSize(int pageSize){ /V~L:0%
this.pageSize = pageSize; ( y^oGY;
} M
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publicint getTotalCount(){ BzF.KCScs
return totalCount; ogMLv}
} *]z.BZI:
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publicvoid setTotalCount(int totalCount){ I"Ji_4QV
if(totalCount > 0){ /`hr)
this.totalCount = totalCount; ' F`*(\#
int count = totalCount / 84b;G4K
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pageSize; NUH;GMj,,
if(totalCount % pageSize > 0) Y::fcMJr;Q
count++; o}v #Df
indexes = newint[count]; \qQ5x
for(int i = 0; i < count; i++){ 7t5X
indexes = pageSize * 7oF`Os+U
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} @5
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this.totalCount = 0; ,9|%
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} )oTEB#J
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publicint[] getIndexes(){ u>&\@?(
return indexes; 8)5n
} 34YYw@?}Y
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publicvoid setIndexes(int[] indexes){ FtM7+>Do.
this.indexes = indexes; z"}k\B-5
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publicint getStartIndex(){ Lj *FKP\{
return startIndex; }K~JM1(26
} <B`}18x
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publicvoid setStartIndex(int startIndex){ 68FxM#xR
if(totalCount <= 0) 6xdu}l=%
this.startIndex = 0; FPaj
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elseif(startIndex >= totalCount) -J[zJ4z#
this.startIndex = indexes *^Zt5 zk
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[indexes.length - 1]; IS&`O=7
elseif(startIndex < 0) C>v
this.startIndex = 0; W{ eu_
else{ {Hp?rY@
this.startIndex = indexes P|h<|Gcp
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} IL.Jx:(0
} Redp'rXT<h
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publicint getNextIndex(){ (ZShh y8g
int nextIndex = getStartIndex() + pal))e!B
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pageSize; ~lDLdUs
if(nextIndex >= totalCount) b8b-M]P-=
return getStartIndex(); qu[w_1%S
else 4c2P%X(
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return nextIndex; V.y+u7<3}
}
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publicint getPreviousIndex(){ iM8hGQ`
int previousIndex = getStartIndex() - zNE!m:s
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pageSize; *N>Qj-KAM_
if(previousIndex < 0) te6[^_k
return0; ,<EmuEw |
else .Z_U]_(
return previousIndex; GbP!l;a
} /2FX"I[0V%
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} I.KYWs
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抽象业务类 LrPDpTd
java代码: GC4$9q}C4Z
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/** 46XB6z01
* Created on 2005-7-12 N23s{S t
*/ n|,Es!8:o
package com.javaeye.common.business; XX6&%7(
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import java.io.Serializable; xje{kx#
import java.util.List; yLDHJ}R
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import org.hibernate.Criteria; ;euWpE;E\#
import org.hibernate.HibernateException; mceSUKI;L
import org.hibernate.Session; Ce:R
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import org.hibernate.criterion.DetachedCriteria; =x7ODBYW^
import org.hibernate.criterion.Projections; Ev^Xs6 }"
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org.springframework.orm.hibernate3.HibernateCallback; R
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import 4k#B5^iJ
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org.springframework.orm.hibernate3.support.HibernateDaoS 2X*epU_1h
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import com.javaeye.common.util.PaginationSupport; BKDWd]KEf
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public abstract class AbstractManager extends ;JZXSM-3
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HibernateDaoSupport { Q1jyetk~I
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privateboolean cacheQueries = false; F;b|A`M
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privateString queryCacheRegion; qnA:[H;F
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publicvoid setCacheQueries(boolean ;8T<L[ ^U
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cacheQueries){ zu^ AkMc
this.cacheQueries = cacheQueries; $<aBawLZO
} "|Pl(HX
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publicvoid setQueryCacheRegion(String YLCwo]\+>
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queryCacheRegion){ NNfCJ|
this.queryCacheRegion = nuC K7X
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queryCacheRegion; ~'U;).C
} )T4L^^`
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publicvoid save(finalObject entity){ z)0VP QMT
getHibernateTemplate().save(entity); Kz<xu ulr
} 0)/214^&
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publicvoid persist(finalObject entity){ S1+#qs{5a
getHibernateTemplate().save(entity); .Gv~e!a8
} Ym6ec|9;
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publicvoid update(finalObject entity){ D~y]d
getHibernateTemplate().update(entity); <N*>9S,}
} x$Dv&4
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publicvoid delete(finalObject entity){ n;=A'g|Q
getHibernateTemplate().delete(entity); e7qT;
} cpy"1=K~M
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publicObject load(finalClass entity, (]V.#JM
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finalSerializable id){ ~"wD4Ue
return getHibernateTemplate().load nY8UJy}<oL
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(entity, id); )s8r(.W
} e56#Qb@$\
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publicObject get(finalClass entity, XgbGC*dQ
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finalSerializable id){ ]lo1Kw
return getHibernateTemplate().get 5^Y/RS i
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(entity, id); Qnw$=L:
} ~3%3{aa
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publicList findAll(finalClass entity){ Z\L@5.*ydE
return getHibernateTemplate().find("from _qg6(
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} k|_2aQ02
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publicList findByNamedQuery(finalString |.
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namedQuery){ |]q=D1/A
return getHibernateTemplate saT9%?4-
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().findByNamedQuery(namedQuery); p3S c4
} [s/@z*,M1
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publicList findByNamedQuery(finalString query, n,F00YR
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finalObject parameter){ $ {+.1"/[
return getHibernateTemplate zfZDtKq
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().findByNamedQuery(query, parameter); VMWg:=~$
} }"-r;i
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publicList findByNamedQuery(finalString query, f+920/>!Z
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finalObject[] parameters){ X\x9CA
return getHibernateTemplate /kz&9FM
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().findByNamedQuery(query, parameters); 9yh@_~rZ
} zFn&~lFB
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publicList find(finalString query){ Wa(S20yF
return getHibernateTemplate().find ]'Yw#YB
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(query); X{
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publicList find(finalString query, finalObject #H`y1zm
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parameter){ _p&$X
return getHibernateTemplate().find ;N\?]{ L
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(query, parameter); j 7URg>i0
} nrIL_
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public PaginationSupport findPageByCriteria uE j6A
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(final DetachedCriteria detachedCriteria){ hBhkb ~Oky
return findPageByCriteria 6\;1<Sw*
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); \zU5G#LQ
} ?U08A{ c
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public PaginationSupport findPageByCriteria V+24- QWh
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(final DetachedCriteria detachedCriteria, finalint 3(+#^aw
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startIndex){ 6t:c]G'J
return findPageByCriteria 'I]"=O,
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(detachedCriteria, PaginationSupport.PAGESIZE, MjB[5:s
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startIndex); Td*Oljj._U
} XL^N5
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public PaginationSupport findPageByCriteria <y!r~?
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(final DetachedCriteria detachedCriteria, finalint 0@lC5-=
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pageSize, L_"(A
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finalint startIndex){ T''+zk
return(PaginationSupport) Ts .Zl{B
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getHibernateTemplate().execute(new HibernateCallback(){ Xp6*Y1Y
publicObject doInHibernate c)MR+'d\WO
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(Session session)throws HibernateException { [IFRwQ^%_O
Criteria criteria = ;Ia1L{472m
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detachedCriteria.getExecutableCriteria(session); MuV0;K\
int totalCount = SRN9(LN
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((Integer) criteria.setProjection(Projections.rowCount * g4Cy8$
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()).uniqueResult()).intValue(); ^YJA\d@
criteria.setProjection WWW#s gM%
{ $/Fk6qr
(null); >JPJ%~y
List items = }.UI&UZ-
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criteria.setFirstResult(startIndex).setMaxResults Hu8atlpo
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(pageSize).list(); *}ee"eHs
PaginationSupport ps = z-G7Y#
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new PaginationSupport(items, totalCount, pageSize, yI.H4Dl<
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startIndex); q'F_j"
return ps; yj'' \
} `.(S#!gw
}, true); \h7J/es^p!
} Mp"ci+Iu
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public List findAllByCriteria(final BrH;(*H)8
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DetachedCriteria detachedCriteria){ ClMtl59
return(List) getHibernateTemplate k>&s(b
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().execute(new HibernateCallback(){ A?D"j7JD=L
publicObject doInHibernate e=o{Zo?H=
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(Session session)throws HibernateException { x56
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Criteria criteria = e9@fQ
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detachedCriteria.getExecutableCriteria(session); !N8)C@=
return criteria.list(); XDdcq ]*|
} &lPBqw
}, true); Kwl qi]~
} @y0bU*v7
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public int getCountByCriteria(final f'6qJk%J
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DetachedCriteria detachedCriteria){ 9MB\z"b?A
Integer count = (Integer) T]#,R|)d
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getHibernateTemplate().execute(new HibernateCallback(){ vN,}aV2nq
publicObject doInHibernate _A,-[*OKI
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(Session session)throws HibernateException { $;2eH
Criteria criteria = p~q_0Pg%
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detachedCriteria.getExecutableCriteria(session); ()C^ta_]
return g)9JO6]
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criteria.setProjection(Projections.rowCount K\KO5A
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()).uniqueResult(); adO!Gs9f?
} I,<>%Z|'
}, true); \'??
return count.intValue(); Jn[q<e"
} LPapD@Z
} t}XB|h
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用户在web层构造查询条件detachedCriteria,和可选的 nI*(a:
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 i_0,BVC
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PaginationSupport的实例ps。 9*=@/1
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ps.getItems()得到已分页好的结果集 7"n)/;la
ps.getIndexes()得到分页索引的数组 YMj7
ps.getTotalCount()得到总结果数 )&Kn(l)
ps.getStartIndex()当前分页索引 +e0dV_T_>
ps.getNextIndex()下一页索引 |
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ps.getPreviousIndex()上一页索引 T$n>7X-r
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 Ez/\bE
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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 kMl @v`
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一下代码重构了。 .*EOVo9S
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我把原本我的做法也提供出来供大家讨论吧: ^A *]&%(h
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首先,为了实现分页查询,我封装了一个Page类: Sv~YFS :oy
java代码: @ate49W
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/*Created on 2005-4-14*/ z"6ZDC6
package org.flyware.util.page; (#j2P0B
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/** {?EEIfg
* @author Joa aCU7w5
* -5V)q.Og
*/ e;A^.\SP
publicclass Page { 8zQ_xE
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/** imply if the page has previous page */ L.09\1?.n
privateboolean hasPrePage; W{fULl
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/** imply if the page has next page */ Kk!6B
privateboolean hasNextPage; >a&