Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 V+>RF
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 R3_;!/1
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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"@p3$2QW
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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 dQH8s
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分页支持类: `{w|2 [C3
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java代码: H
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package com.javaeye.common.util; $i8oLSRV
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import java.util.List; ^Bw"+ 6d
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publicclass PaginationSupport { &kWT<*;J)
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publicfinalstaticint PAGESIZE = 30; 5A %TpJ
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privateint pageSize = PAGESIZE; I)3LJK
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privateList items; Wa?\W&
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privateint totalCount; -yIx:*KI
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privateint[] indexes = newint[0]; <Z1m9O "sy
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privateint startIndex = 0; (S=CxK
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public PaginationSupport(List items, int 6: R1jF*eG
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totalCount){ z^KBV^n
setPageSize(PAGESIZE); [4])\q^q
setTotalCount(totalCount); 7/=r-
setItems(items); C1YH\X(r
setStartIndex(0); T%PUV \LV
} _>t6]?*
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public PaginationSupport(List items, int zP!j {y4w
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totalCount, int startIndex){ )5diX
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setPageSize(PAGESIZE); JAmpU^(C
setTotalCount(totalCount); +=kz".$
setItems(items); w/ID yQ
setStartIndex(startIndex); 9PR?'X;4
} ,G$<J0R1
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public PaginationSupport(List items, int @Rqn&tA8
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totalCount, int pageSize, int startIndex){ =^ x1:Ak
setPageSize(pageSize); `y&2Bf
setTotalCount(totalCount); SUoUXh^!w
setItems(items); R36A_
setStartIndex(startIndex); 7a%)/)<D
} 5.U|CL
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publicList getItems(){ @PKY>58)
return items; ZlL]AD@
} $r(9'm}W
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publicvoid setItems(List items){ P[gYENQ
this.items = items; T$Rf
} }}d,xI
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publicint getPageSize(){ T5TAkEVl
return pageSize; = iWn
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} f2M}N
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publicvoid setPageSize(int pageSize){ 5oY^;)\/
this.pageSize = pageSize; f]kG%JEK
} ggzcANCD<
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publicint getTotalCount(){ <L<d_
return totalCount; &jE@i#
} FWQNO(
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publicvoid setTotalCount(int totalCount){ _h P7hhR
if(totalCount > 0){ 9at_F'>R
this.totalCount = totalCount;
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int count = totalCount / _G^Cc}X
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pageSize; 9 EV. ![
if(totalCount % pageSize > 0) %v<BE
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count++; /n8\^4{fP{
indexes = newint[count]; eIt<da<G?
for(int i = 0; i < count; i++){ yey]#M[y
indexes = pageSize * Ox&]{
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} f2Z(hYH~
}else{ A $W~R
this.totalCount = 0; .%+y_.l
} s73' h
} ^_G@a,
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publicint[] getIndexes(){ +W}6o3x~
return indexes; T3h 1eU
} z--Y
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publicvoid setIndexes(int[] indexes){ 5O"$'iL
this.indexes = indexes; #7p!xf^
} ;><m[ l6
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publicint getStartIndex(){ sff4N>XAl<
return startIndex; "WzD+<oL
} Gm-V/[29R
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publicvoid setStartIndex(int startIndex){ g,s^qW0vds
if(totalCount <= 0) N%!{n7`N:
this.startIndex = 0; FPukV^
elseif(startIndex >= totalCount) lYhC2f
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this.startIndex = indexes >- U+o.o
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[indexes.length - 1]; cr ~.],$Om
elseif(startIndex < 0) D4$2'h
this.startIndex = 0; w[OUGn'
else{ e@7UL|12
this.startIndex = indexes Tb}op XYK
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[startIndex / pageSize]; |G/WS0
} x.Tulo0/
} [G'
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publicint getNextIndex(){ &1ZUMc
int nextIndex = getStartIndex() + YFP<^y=
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pageSize; H
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if(nextIndex >= totalCount) !wTrWD!
return getStartIndex(); 2@Oz _?O=
else z! :0%qu
return nextIndex; lcK4 Uq\q
} -^q;e]+J
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publicint getPreviousIndex(){ YP>J'{?b*"
int previousIndex = getStartIndex() - Vllxv6/_
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pageSize; ik1asj1
if(previousIndex < 0) !6,rN_a@Y
return0; X.ecA`0
else .q1y)l-^Z
return previousIndex; !,]2.:{0z
} oX7_v_:J\R
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} Z<,Hz+
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抽象业务类 F}=_"IkZ
java代码: YQb503W"d~
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/** cg_ " }]Y1
* Created on 2005-7-12 H3 -?cy
*/ L/In~'*-
package com.javaeye.common.business; z[6avW"q
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import java.io.Serializable; [5ncBY*A7
import java.util.List; LH.Gf
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import org.hibernate.Criteria; W =;,ls
import org.hibernate.HibernateException; $@O?
import org.hibernate.Session;
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import org.hibernate.criterion.DetachedCriteria; -}PE(c1%?q
import org.hibernate.criterion.Projections; MV2$0
import KDP"z
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org.springframework.orm.hibernate3.HibernateCallback; ]#W7-Q;]
import V^4v`}Wgx
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org.springframework.orm.hibernate3.support.HibernateDaoS 0U:X[2|)
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upport; (P;TM1k
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import com.javaeye.common.util.PaginationSupport; }V*?~.R
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public abstract class AbstractManager extends [VqiF~o,
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HibernateDaoSupport { a6cU<(WDeh
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privateboolean cacheQueries = false; ZZZ`@pXm;
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privateString queryCacheRegion; M$.bC0}T
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publicvoid setCacheQueries(boolean :*BN>*1^\r
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cacheQueries){ ^*4#ZvpG2
this.cacheQueries = cacheQueries; Pz[UAJ
} .ahY 1CO
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publicvoid setQueryCacheRegion(String D\+x/r?-I
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queryCacheRegion){ maHz3:
this.queryCacheRegion = 9H;Os:"\|
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queryCacheRegion; 5._QI/d)'J
} P^=B6>e
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publicvoid save(finalObject entity){ !vRN'/(Vyu
getHibernateTemplate().save(entity); f*rub. y
} Q]GS#n
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publicvoid persist(finalObject entity){ WRkuPj2
getHibernateTemplate().save(entity); QxaMe8(
} ?Fa$lE4
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publicvoid update(finalObject entity){ H7P}=YW".
getHibernateTemplate().update(entity); x9\{a
} -6uLww=w4
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publicvoid delete(finalObject entity){ ^Ss<<
getHibernateTemplate().delete(entity); D4(73
} LgX2KU"
@
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publicObject load(finalClass entity, A{B$$7%
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finalSerializable id){ F=5vAv1
return getHibernateTemplate().load RrrlfF ms
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(entity, id); 35AH|U7b
} >
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publicObject get(finalClass entity, |B$JX'_
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finalSerializable id){ q[vO
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return getHibernateTemplate().get y
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(entity, id); U
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} ? N]bFW"t|
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publicList findAll(finalClass entity){ JUDZ_cGr
return getHibernateTemplate().find("from H3d|eO4+W
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" + entity.getName()); ;UX9Em
} 0L"uU3
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publicList findByNamedQuery(finalString !f/^1k}SR
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namedQuery){ a04S&ezj
return getHibernateTemplate rc%*g3ryLG
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().findByNamedQuery(namedQuery); !{uV-c-5,
} 1ATH$x
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publicList findByNamedQuery(finalString query, aG@GJ@w
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finalObject parameter){ ZWx[@5
return getHibernateTemplate R5uz<
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().findByNamedQuery(query, parameter); x5U;i
} hiR+cPSF
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publicList findByNamedQuery(finalString query, &\/}.rF
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finalObject[] parameters){ G
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return getHibernateTemplate ;%u)~3B$JK
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().findByNamedQuery(query, parameters); a5@lWpQsV
} ;]/cCi
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publicList find(finalString query){ xxdxRy9/
return getHibernateTemplate().find \nV oBW(
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(query); *nUa0Zg4q6
} O}lqY?0*
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publicList find(finalString query, finalObject 5hiuBf<
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parameter){ +n 8,=}
return getHibernateTemplate().find cC,gd\}M
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(query, parameter); U3c !*i
} SY2((!n._
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public PaginationSupport findPageByCriteria Yg`z4U'6~
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(final DetachedCriteria detachedCriteria){ &4L+[M{J@4
return findPageByCriteria ;\+A6(GX{
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); |<7nf7 5c}
} \RTX fe-`
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public PaginationSupport findPageByCriteria z#|tl/aP9
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(final DetachedCriteria detachedCriteria, finalint !O8vr4=
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startIndex){ V|dKKb[Lve
return findPageByCriteria %OsV(7
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(detachedCriteria, PaginationSupport.PAGESIZE, \LW
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startIndex); Wj.
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} -n$fh::^
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public PaginationSupport findPageByCriteria 4;d9bd)A
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(final DetachedCriteria detachedCriteria, finalint =2[cpF]
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pageSize, m)?cXM
finalint startIndex){ 3AD^B\<gB
return(PaginationSupport) #|
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getHibernateTemplate().execute(new HibernateCallback(){ GP/3r[MH
publicObject doInHibernate {*%'vVv+
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(Session session)throws HibernateException { s&$Zgf6Z
Criteria criteria = aKC3T-
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detachedCriteria.getExecutableCriteria(session); ?<slB>8
int totalCount = q-}J0vu\K
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((Integer) criteria.setProjection(Projections.rowCount '?k*wEu
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()).uniqueResult()).intValue(); d+fig{<b
criteria.setProjection _>*$%R
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(null); 7@Qz
List items = sT3O_20{
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criteria.setFirstResult(startIndex).setMaxResults cQUmcK/,
'on, YEp
(pageSize).list(); m`-{ V<(M
PaginationSupport ps = c X553&
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new PaginationSupport(items, totalCount, pageSize, qMz0R\4
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startIndex); ,?7URx*
return ps; W04-D
} }dE0WJcO
}, true); 5"6Y=AuQ6
} O6;7'
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public List findAllByCriteria(final q!9SANTx
uQ{ &x6.1
DetachedCriteria detachedCriteria){ Je+z\eT!5<
return(List) getHibernateTemplate zD-.bHo>.
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().execute(new HibernateCallback(){ B9n$8QS
publicObject doInHibernate `(EY/EsY
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(Session session)throws HibernateException { U*=ebZno
Criteria criteria = sUcx;<|BC
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detachedCriteria.getExecutableCriteria(session); +EJIYvkFm
return criteria.list(); )avli@W-3j
} -Yy,L%E]F:
}, true); Lt.a@\J'_
} ub6=^`>h
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public int getCountByCriteria(final :03w k)
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DetachedCriteria detachedCriteria){ ksT2_Ic
Integer count = (Integer) r%JJ5Al.S
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getHibernateTemplate().execute(new HibernateCallback(){ 1j
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publicObject doInHibernate \IbGNV`q
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(Session session)throws HibernateException { (hS
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Criteria criteria = _<|NVweFS
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detachedCriteria.getExecutableCriteria(session); +LCpE$H
return J1T_wA_
0
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criteria.setProjection(Projections.rowCount |TatRB3>
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()).uniqueResult(); Ly0^ L-~|
} +hI:5(_
}, true); F$y3oX
return count.intValue(); N?TXPY
} `h}fS4CO
} Z1
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用户在web层构造查询条件detachedCriteria,和可选的 E1 IT>_
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 82l$]W 4
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PaginationSupport的实例ps。 .\XFhOsa
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ps.getItems()得到已分页好的结果集 2o2jDQ|7
ps.getIndexes()得到分页索引的数组 uF,F<%d
ps.getTotalCount()得到总结果数 |LhVANz
ps.getStartIndex()当前分页索引 -5vg"|ia,
ps.getNextIndex()下一页索引 0z&]imU
ps.getPreviousIndex()上一页索引 Iv])s
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 4JQd/;
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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 nv$>iJ^~H
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一下代码重构了。 ` /
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我把原本我的做法也提供出来供大家讨论吧: ;wGoEN
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首先,为了实现分页查询,我封装了一个Page类: /q1k)4?E
java代码: DVJuX~'|!
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/*Created on 2005-4-14*/ O>R@Xj)M
package org.flyware.util.page; _2Zc?*4
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/** \/XU v(
* @author Joa Ml,~@}
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* wjtFZGx&
*/ +{~cX]|
publicclass Page { af@R\"N9c
#~}4< 18
/** imply if the page has previous page */ g"{`g6(+
privateboolean hasPrePage; @`mr|-Rp@
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/** imply if the page has next page */ &s#O iF8
privateboolean hasNextPage; y3XR:d1cg
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/** the number of every page */ *epK17i=
privateint everyPage; xWK0p'E0
n\GN}?4
/** the total page number */ DX0#q #
privateint totalPage; %E8HLTEvl
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/** the number of current page */ \J(kevX
privateint currentPage; lLur.f
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/** the begin index of the records by the current :jAsm[
[_`<<!u>-
query */ A(9$!%#+L
privateint beginIndex; =qvn?I^/
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/** The default constructor */ =}"P;4:
public Page(){ CZ!gu Y=
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} 1! j^
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/** construct the page by everyPage >Qqxn*O
* @param everyPage +4n}H}9l
* */ Sc ijf 9
public Page(int everyPage){ ai<K6)
this.everyPage = everyPage; &lo<sbd.
} G?^w
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/** The whole constructor */ ?e%u[ Q0
public Page(boolean hasPrePage, boolean hasNextPage, \=[38?QOY
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int everyPage, int totalPage, HqI[]T@
int currentPage, int beginIndex){ iL<FFN~{
this.hasPrePage = hasPrePage; BM9:|}\J65
this.hasNextPage = hasNextPage; RWB]uHzE
this.everyPage = everyPage; _PLZ_c:O
this.totalPage = totalPage; r3Kx
this.currentPage = currentPage; q&&uX-ez5W
this.beginIndex = beginIndex; N3V4Mpf
} "u'dd3!
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/** gk}.LE
* @return [,Y;#;
* Returns the beginIndex. ?es9j]
*/ @.=2*e.z|b
publicint getBeginIndex(){ ]vuxeu[cu,
return beginIndex; Sq5}v]k@&
} ug/P>0
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/** rW)}$|-Z
* @param beginIndex 1`1Jn*|TI
* The beginIndex to set. U4lAo
*/ {;38&