Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 X2`>@GR/>
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 |z'?3?,~
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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 K[[k,W]qb
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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 [*G2wP[$
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分页支持类: `$H
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java代码: q?L(V+X
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package com.javaeye.common.util; sQZ8<DpB
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import java.util.List; >#?: x*[
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publicclass PaginationSupport { 2-0cB$W+
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publicfinalstaticint PAGESIZE = 30; k_>{"Rc
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privateint pageSize = PAGESIZE; 5$U>M
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privateList items; =-LX)|x}
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privateint totalCount; <UJJ],)^1A
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privateint[] indexes = newint[0]; (Fzh1#
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privateint startIndex = 0; %uVJLz
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public PaginationSupport(List items, int jHH
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totalCount){ 4oV_b"xz~
setPageSize(PAGESIZE); ""3m!qn#
setTotalCount(totalCount); 1lyOp
setItems(items); \Z20fh2
setStartIndex(0); 6^O?p2xpo
} yVHlT
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public PaginationSupport(List items, int N5s|a5
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totalCount, int startIndex){ gkML .u
setPageSize(PAGESIZE); ef}E.Bl
setTotalCount(totalCount); eH%L?"J~:
setItems(items); =+}}Sv2
setStartIndex(startIndex); Pgw%SMEp
} U@J/
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public PaginationSupport(List items, int ~Oq,[,W
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totalCount, int pageSize, int startIndex){ QHs:=i~VH
setPageSize(pageSize); (_qBsng:
setTotalCount(totalCount); 6!%d-Z7)
setItems(items); ]Uu(OI<)
setStartIndex(startIndex); .\~P -{Hd
} w}W@M,.^
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publicList getItems(){ 6+$d
return items; @SC-vc
} {8#N7(%z
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publicvoid setItems(List items){ r($_>TS&"
this.items = items; <a+eF}*2
} 4/2RfDp
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publicint getPageSize(){ 5G'&9{oB
return pageSize; c[h'`KXJf-
} u1;e*ty
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publicvoid setPageSize(int pageSize){ )-.Cne;n
this.pageSize = pageSize; (Gi+7GMV'
} t ?9;cS4
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publicint getTotalCount(){ JMirz~%ib
return totalCount; 7"n)/;la
} iM/*&O}
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publicvoid setTotalCount(int totalCount){ ti{H(;;@
if(totalCount > 0){ u+z .J4w
this.totalCount = totalCount; /OhaERv
int count = totalCount / m]0^
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pageSize; S2'`|uI
if(totalCount % pageSize > 0) z;bH<cQ
count++; HzD> -f
indexes = newint[count]; nE]~E xr
for(int i = 0; i < count; i++){ @ate49W
indexes = pageSize * YQ 8j
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i; 1Lm].tq
} Ad]<e?oN=
}else{ ]RH=s7L
this.totalCount = 0; `ICcaRIN8I
} |D;_:x9
} 8!u/
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publicint[] getIndexes(){ 93Mdp9v+i
return indexes; Y!++CMzU
} #&^ZQs<
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publicvoid setIndexes(int[] indexes){ M1AZ}bc0]
this.indexes = indexes; ,}9f(`
} CrnB{Z4L
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publicint getStartIndex(){ *Rz{44LP&
return startIndex; tWpl`HH
} k~0#'I9
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publicvoid setStartIndex(int startIndex){ H|PrsGW
if(totalCount <= 0) _:wZmZU}
this.startIndex = 0; IXGW2z;
elseif(startIndex >= totalCount) GN\8![J
this.startIndex = indexes wXc,F D$
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[indexes.length - 1]; q<-%L1kc1
elseif(startIndex < 0) >?S\~Y
this.startIndex = 0; s{yJ:WncI
else{ ^Vag1(hdq
this.startIndex = indexes ^g9}f
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[startIndex / pageSize]; E;9Z\?P
} iPMB$SdfO
} g93I+
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publicint getNextIndex(){ D~Z=0yD
int nextIndex = getStartIndex() + ?#?e(mpo
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pageSize; T'hml
if(nextIndex >= totalCount) ,,S9$@R
return getStartIndex(); llNXQlP\B
else [u[ U_g*
return nextIndex; mj)PLZ]
} WS5A Y @(~
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publicint getPreviousIndex(){ (/'h4KS@
int previousIndex = getStartIndex() - 5!~!j
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pageSize; \[cH/{nt
if(previousIndex < 0) 3:UA<&=s
return0; U M@naU
else (s088O
return previousIndex; t')h{2&&!2
} !#. \QU|
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} :.DI_XN`
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抽象业务类 p zg&/m&F`
java代码: ~Yl<S(/4
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/** WKxm9y
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* Created on 2005-7-12 vb
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*/ \BUqDd!
package com.javaeye.common.business; v~}5u
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import java.io.Serializable; K@6`-|I
import java.util.List; -?5$ PH
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import org.hibernate.Criteria; jXWNHIl)@
import org.hibernate.HibernateException;
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import org.hibernate.Session; S*g`d;8gV
import org.hibernate.criterion.DetachedCriteria; 7WP%J-
import org.hibernate.criterion.Projections; =-qf ;5[|
import y:,9I`aW
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org.springframework.orm.hibernate3.HibernateCallback; HlPG3LD!
import (f~gEKcB2u
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org.springframework.orm.hibernate3.support.HibernateDaoS TP{Gt.e
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upport; `L\)ahM
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import com.javaeye.common.util.PaginationSupport; z,x"a
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public abstract class AbstractManager extends qm'b'!gq~
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HibernateDaoSupport { ik5|,#}m&
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privateboolean cacheQueries = false; j#VIHCzlr
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privateString queryCacheRegion; 6IP$n($2
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publicvoid setCacheQueries(boolean
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cacheQueries){ (ua q<Cvg
this.cacheQueries = cacheQueries; #*2Rp8n
} SY1GR n
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publicvoid setQueryCacheRegion(String P+Z\3re
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queryCacheRegion){ p)3nyN=|_
this.queryCacheRegion = #3 bv3m
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queryCacheRegion; (A{NF(
} (Z-l/)Q
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publicvoid save(finalObject entity){ 0E6lmz`O
getHibernateTemplate().save(entity); GaBTj_3
} 8!zbF<W9
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publicvoid persist(finalObject entity){ L.B~ax.|Z
getHibernateTemplate().save(entity); >F3.c%VU]w
} `#6x=24
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publicvoid update(finalObject entity){ *)> do
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getHibernateTemplate().update(entity); vPmnN^
} Mo^`\/x!
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publicvoid delete(finalObject entity){ ;%zC@a~{
getHibernateTemplate().delete(entity); qn"K9k
} H}nJbnU
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publicObject load(finalClass entity, EJm4xkYLj1
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finalSerializable id){ @`|)Ia<
return getHibernateTemplate().load k+1gQru{d
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(entity, id); w%xCTeK[
} R1%y]]*-P
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publicObject get(finalClass entity, 8eyl,W=dn
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finalSerializable id){ wss?|XCI
return getHibernateTemplate().get {gU&%j
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(entity, id); g`?:=G:a*
} MYdx .NZT
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publicList findAll(finalClass entity){ /fwgqFVk
return getHibernateTemplate().find("from dGkgaC+
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" + entity.getName()); 4~|<`vqN
} ngyY
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publicList findByNamedQuery(finalString va,~w(G
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namedQuery){ |_zO_F rtp
return getHibernateTemplate edpW8eND
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().findByNamedQuery(namedQuery); +m/,,+4
} JwP:2-o
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publicList findByNamedQuery(finalString query, oH-8r:{
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finalObject parameter){ 8^ #mvHah
return getHibernateTemplate TV:<TR
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().findByNamedQuery(query, parameter); &<1`O
} fx?$9(r,
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publicList findByNamedQuery(finalString query, HL 8eD^
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finalObject[] parameters){ @Icq1zb]
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return getHibernateTemplate x';uCKWV
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().findByNamedQuery(query, parameters); sb.J
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} GozPvR^/
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publicList find(finalString query){ +5X DF
return getHibernateTemplate().find *'8Ln tZf
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(query); G|4^_`-
} hIU(P Dl4
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publicList find(finalString query, finalObject A lwtmDa
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parameter){ 6"QEJ
return getHibernateTemplate().find HW[L[&/
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(query, parameter); q``wt
} Vxdp|
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public PaginationSupport findPageByCriteria C/tr$.2H=
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(final DetachedCriteria detachedCriteria){ PkUd~c
return findPageByCriteria j^SZnMQf
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); YT-=;uK^S
} ?Rr2/W#F
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public PaginationSupport findPageByCriteria ]z ==
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(final DetachedCriteria detachedCriteria, finalint ?6N3tk-2
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startIndex){ uzU{z;
return findPageByCriteria WFv!Pbq,
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(detachedCriteria, PaginationSupport.PAGESIZE, B$a-og(
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startIndex); (Tvcq
} "v]%3i.*
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public PaginationSupport findPageByCriteria )u} Q:`9
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(final DetachedCriteria detachedCriteria, finalint +RDJY(Y$
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pageSize, 3YL
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finalint startIndex){ + ,4"
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return(PaginationSupport) Ngy=!g?Hk=
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getHibernateTemplate().execute(new HibernateCallback(){ xBM>u,0.F
publicObject doInHibernate nWYCh7
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(Session session)throws HibernateException { tY/vL^mi
Criteria criteria = !!,0'c
@!%n$>p/V
detachedCriteria.getExecutableCriteria(session); b]fzRdhl
int totalCount = -j2 (R?a
n=sXSxl
((Integer) criteria.setProjection(Projections.rowCount O<*5$,K9
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()).uniqueResult()).intValue(); <z)m%*lvU
criteria.setProjection (/{aJV
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(null); P,xwSvO#M
List items = nvq3*
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criteria.setFirstResult(startIndex).setMaxResults v! hY
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(pageSize).list(); gX @`X
PaginationSupport ps = =?Fkn4t
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new PaginationSupport(items, totalCount, pageSize, 1T|$BK@)
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startIndex); oOU1{[
return ps; /BA{O&Ro^
} ^4Uw8-/ 9
}, true); /pH(WHT+/H
} Nn6S
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public List findAllByCriteria(final |`rJJFA
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DetachedCriteria detachedCriteria){ @_ygnNn4R
return(List) getHibernateTemplate EMvHFu
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().execute(new HibernateCallback(){ hUpnI@
publicObject doInHibernate wTq{ sW&
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(Session session)throws HibernateException { T2'RATfG
Criteria criteria = n%%7KTqu
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detachedCriteria.getExecutableCriteria(session); X"asfA[6K
return criteria.list(); - xm{&0e)
} $9!D\N,}]C
}, true); }M>rE
} ~eh0[mF^]
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public int getCountByCriteria(final PH3 >9/H
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DetachedCriteria detachedCriteria){ X*eW#|$\
Integer count = (Integer) `{K_/Cit
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getHibernateTemplate().execute(new HibernateCallback(){ GRqT-/n"
publicObject doInHibernate |pZUlQbb
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(Session session)throws HibernateException { 8P' ana
Criteria criteria = ?
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detachedCriteria.getExecutableCriteria(session); KDP H6
return ZAKeEm2A
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criteria.setProjection(Projections.rowCount G[Lpe
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()).uniqueResult(); '])2k@o@
} lK7m=[j
}, true); ;
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return count.intValue(); )v4b
} >JwLk[=j
} u"xJjS
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用户在web层构造查询条件detachedCriteria,和可选的 ">81J5qgd
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 /t<@"BoV
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PaginationSupport的实例ps。 2S3lsp5!
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ps.getItems()得到已分页好的结果集 /Dtd#OAdr
ps.getIndexes()得到分页索引的数组 RC#C\S6
ps.getTotalCount()得到总结果数 1SIq[1
ps.getStartIndex()当前分页索引 YV4#%I!<
ps.getNextIndex()下一页索引 smY$-v)@
ps.getPreviousIndex()上一页索引 NG&_?|OmV
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 DHC+C4
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 (m[bWdANnW
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一下代码重构了。 ^-CINt{O
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我把原本我的做法也提供出来供大家讨论吧: %%ae^*[!n
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首先,为了实现分页查询,我封装了一个Page类: J~B
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java代码: bOp54WI-g
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/*Created on 2005-4-14*/ g$:Xuw1
package org.flyware.util.page; @XD+' {]
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/** 5Ky#GuC
* @author Joa gk BdR +
* ,vqr<H9e
*/ e
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publicclass Page { )Rat0$6
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/** imply if the page has previous page */ vzel#
privateboolean hasPrePage; r,goRK.
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/** imply if the page has next page */ /N>e&e[35\
privateboolean hasNextPage; /WV7gO&L1
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/** the number of every page */ $P7iRM]
privateint everyPage; zOEY6lAwI
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/** the total page number */ l:6,QaT1
privateint totalPage; MaBYk?TR~
/:6Wzj
/** the number of current page */ 6J~12TU,
privateint currentPage; HBys
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/** the begin index of the records by the current =@u 5|:
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query */ FEPXuCb
privateint beginIndex; &~UJf4b|A
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/** The default constructor */ w#JJXXQI
public Page(){ xR"M*%{@0
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} ;U:
{/
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/** construct the page by everyPage 6*l^1;U
* @param everyPage zL5d0_E9
* */ !|2VWI}
public Page(int everyPage){ ;o/>JHGj
this.everyPage = everyPage; e&MC|US=\
} 1[*UYcD
}
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/** The whole constructor */ d_S*#/k
public Page(boolean hasPrePage, boolean hasNextPage, a"/#+=[
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int everyPage, int totalPage, PqNFyQkl
int currentPage, int beginIndex){ (F7_S*
this.hasPrePage = hasPrePage; 'B83m#HR#
this.hasNextPage = hasNextPage; 6b8;}],|
this.everyPage = everyPage; Md)zEj`\
this.totalPage = totalPage; V~GWl1#7
this.currentPage = currentPage; nI*/Mhx
this.beginIndex = beginIndex; Mcw4!{l`
} sDgXU@
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/** h@7FY
* @return I O%6 O
* Returns the beginIndex. 0s#vwK13
*/ }}QT HR
publicint getBeginIndex(){ >}~#>Ru
return beginIndex; gADmN8G=
} T0Yiayt
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/** <1w/hy&mWN
* @param beginIndex ~5ZvOX6L2
* The beginIndex to set.
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*/ , xx6$uZ
publicvoid setBeginIndex(int beginIndex){ q,<[hBri-
this.beginIndex = beginIndex; s/"&9F3
} k)S.]!u&G
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/** &