Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 YXOD
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 jWjK -q@Y
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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 t$Ji{t-
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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 "s^@PzQpN
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分页支持类: 745PCC'FK
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java代码: P?-44m#
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package com.javaeye.common.util; )W#g@V)>
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import java.util.List; _Xe< JJvq
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publicclass PaginationSupport { ]zAg6*-/B
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publicfinalstaticint PAGESIZE = 30; *38\&"s4_
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privateint pageSize = PAGESIZE; `2+52q<FO
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privateList items; 2)]*re)
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privateint totalCount; bm|8Jbsb&
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privateint[] indexes = newint[0]; Ee| y[y,
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privateint startIndex = 0; lsf?R'1
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public PaginationSupport(List items, int G9%4d;uFT
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totalCount){ 6f1Y:qK'@
setPageSize(PAGESIZE); I>|?B(F
setTotalCount(totalCount); KLB?GN?Pb
setItems(items); ]C^*C|
setStartIndex(0); BGOI
} /zAx`H
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public PaginationSupport(List items, int HRh".!lxy
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totalCount, int startIndex){ 4Yk(ldR~
setPageSize(PAGESIZE); w=5qth7
setTotalCount(totalCount); cQb%bmBc5
setItems(items); 6UTdy1Qq>
setStartIndex(startIndex); Dbd5d]]n3
} UNHHzTsr?
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public PaginationSupport(List items, int Vh&KfYY
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totalCount, int pageSize, int startIndex){ 6IH^rSUSK
setPageSize(pageSize); C7:Ry)8'I
setTotalCount(totalCount); z9ZAY!Zhq]
setItems(items); $cedO']
setStartIndex(startIndex); 75ob1h"
} BGS6uV4^>
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publicList getItems(){ &,xM;8b
return items; wXnt3)e
} 1lM0pl6M
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publicvoid setItems(List items){ {I
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this.items = items; N4pA3~P
} QO%K`}Q}
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publicint getPageSize(){ 7+bzCDKU
return pageSize; &3efJ?8
} t+tGN\q
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publicvoid setPageSize(int pageSize){ O1"!'Gk[!L
this.pageSize = pageSize; @2<J_Ja
} wl4yNC
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publicint getTotalCount(){ P!/8
return totalCount; AKVmUS;70
} <|@9]>z
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publicvoid setTotalCount(int totalCount){ bPEAG=l "-
if(totalCount > 0){ J.*=7zmw
this.totalCount = totalCount; 5sH ee,
int count = totalCount / l`k3!EZDS
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pageSize; ,3K?=e2
if(totalCount % pageSize > 0) AMr 9rB d
count++; M:~#"lfK
indexes = newint[count]; sYL+;(#t
for(int i = 0; i < count; i++){ PSE![whK
indexes = pageSize * l6~eb=u;9g
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} [":x
}else{ anbr3L[!
this.totalCount = 0; AQ&;y&+QR
} 9}=Fdt
} JGtdbD?Fw
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publicint[] getIndexes(){ /#a$4 }2L
return indexes; `7LdF,OdE
} xc!"?&\*
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publicvoid setIndexes(int[] indexes){ B`vV[w?
this.indexes = indexes; @!S5FOXipZ
} +mY(6|1
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publicint getStartIndex(){ 7}Gy%SJ`
return startIndex; #q\C"N5ip
} =hA/;
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publicvoid setStartIndex(int startIndex){ 0P|WoCX
if(totalCount <= 0) A
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this.startIndex = 0; lHx$F?
elseif(startIndex >= totalCount) P6MT[
this.startIndex = indexes fE(rDQI
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[indexes.length - 1]; EprgLZ1B
elseif(startIndex < 0) yJ^}uw
this.startIndex = 0; qwN-VCj
else{ Eq|_>f@@8
this.startIndex = indexes BM3nZ<%3
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[startIndex / pageSize]; NK#f Gz*,(
} Q@2Smtu~c
} NJ|8##Z>
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publicint getNextIndex(){ #{0c01JZ
int nextIndex = getStartIndex() + wL:3RZB
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pageSize; oM< 9]jK}
if(nextIndex >= totalCount) 3o z]
return getStartIndex(); [z?<'Tj
else #SO9e.yhI
return nextIndex; 291v
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} R#oXQaBJ
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publicint getPreviousIndex(){ 4re^j4L~o
int previousIndex = getStartIndex() - ,<%],-Lt[
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pageSize; q$K^E
if(previousIndex < 0) 5=l Ava#
return0; #*5A]"k
else H1+G:TM
return previousIndex; w!h!%r
} &ceZu=*
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} EyozhIV
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抽象业务类 [5>0om5
java代码: +[:}<^p?cG
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/** f ~9ADb
* Created on 2005-7-12 Y!}BmRLh2
*/ ]^R;3kU4Q
package com.javaeye.common.business; &vo]l~.
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import java.io.Serializable; jrG@
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import java.util.List; 4k}u`8 a
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import org.hibernate.Criteria; @32JMS<
import org.hibernate.HibernateException; Sky!ZN'I
import org.hibernate.Session; LC2t,!RRl&
import org.hibernate.criterion.DetachedCriteria; xrp%b1Sy
import org.hibernate.criterion.Projections; .(`#q@73
import MYDAS-
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org.springframework.orm.hibernate3.HibernateCallback; %\2
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import nTyKZ(#u
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org.springframework.orm.hibernate3.support.HibernateDaoS ohOze\T)=
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upport; @ITJ}e4
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import com.javaeye.common.util.PaginationSupport; hVd%
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public abstract class AbstractManager extends _}8O15B|
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HibernateDaoSupport { eE '\h
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privateboolean cacheQueries = false; ?v\A&d
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privateString queryCacheRegion; $<OX\f%
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publicvoid setCacheQueries(boolean i]JD::P_H
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cacheQueries){ Ivmiz{Oii
this.cacheQueries = cacheQueries; (Z fY/
} KY~p>Jmh
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publicvoid setQueryCacheRegion(String 4$oNh)+/h
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queryCacheRegion){ ZEYT17g]
this.queryCacheRegion = @FKm_q
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queryCacheRegion; 9w9[0BX#
} -~n^?0
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publicvoid save(finalObject entity){ UzTFT:\
getHibernateTemplate().save(entity); hd^?mZ
} ?Z9C}t]
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publicvoid persist(finalObject entity){ P MV;A{T
getHibernateTemplate().save(entity); *-'u(o
} 0}tf*M+a
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publicvoid update(finalObject entity){ 094~ s
getHibernateTemplate().update(entity); jeXP|;#Una
} :Aj8u\3!@
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publicvoid delete(finalObject entity){ lQ(I/[qVd
getHibernateTemplate().delete(entity); HqC
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} =;Ap+}
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publicObject load(finalClass entity, v<CZ.-r\j
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finalSerializable id){ {| ~
return getHibernateTemplate().load Se~<Vpo
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(entity, id); G8AT]
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} 2MY-9(no
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publicObject get(finalClass entity, qV]p\/a.
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finalSerializable id){ oE/g)m%
return getHibernateTemplate().get "}ibH{$lM
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(entity, id); }\
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} 8k~$_AT>u
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publicList findAll(finalClass entity){ +\Uq=@
return getHibernateTemplate().find("from w8veh[%3n
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" + entity.getName()); t"# .I?S0
} ;|yd}q=p
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publicList findByNamedQuery(finalString S:5vC{
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namedQuery){ lB)%s~P:s
return getHibernateTemplate xD.Uh}:J
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().findByNamedQuery(namedQuery); S2+X/YeB
} iEx
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publicList findByNamedQuery(finalString query, bqPaXH
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finalObject parameter){ !m {d6C[
return getHibernateTemplate [KcF0%a
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().findByNamedQuery(query, parameter); YzA6*2
} ^+J3E4
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publicList findByNamedQuery(finalString query, s2f6;Yc
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finalObject[] parameters){ e};\"^HH
return getHibernateTemplate ] S0tK
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().findByNamedQuery(query, parameters); u=QG%O#B
} y/vGt_^;3<
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publicList find(finalString query){ )swu~Wb}U@
return getHibernateTemplate().find 8el\M/u{
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(query); x*#9\*@EI
} /LK,:6
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publicList find(finalString query, finalObject [`n)2}
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parameter){ O3JBS^;V2
return getHibernateTemplate().find ?mi1PNps#
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(query, parameter); .P:mYC
} x=I|O;"><
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public PaginationSupport findPageByCriteria ^yFtL(x,
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(final DetachedCriteria detachedCriteria){ 3:g~@PB
return findPageByCriteria ix+sT|>
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); Jfs_9g5
} qP5'&!s&!
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public PaginationSupport findPageByCriteria JwNB)e
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(final DetachedCriteria detachedCriteria, finalint ))xP]Mu v
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startIndex){ "8l&m6`U-
return findPageByCriteria %~rXJrK
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(detachedCriteria, PaginationSupport.PAGESIZE, 5fvY#6;
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startIndex); <|>7?#s2=
} :vXlni7N[M
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public PaginationSupport findPageByCriteria /'QfLW>6
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(final DetachedCriteria detachedCriteria, finalint _%gu<Ys
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pageSize, 5H79-QLd
finalint startIndex){ _^MkC}8
return(PaginationSupport) yKB&][)&
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getHibernateTemplate().execute(new HibernateCallback(){ 3aUWQP2
publicObject doInHibernate TfnBPO
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(Session session)throws HibernateException { fq<JX5DER
Criteria criteria = COc
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detachedCriteria.getExecutableCriteria(session); <,+nS%a
int totalCount = (RU\a]Ry
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((Integer) criteria.setProjection(Projections.rowCount =berCV
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()).uniqueResult()).intValue(); N9cCfB\`
criteria.setProjection <5E: ,<
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(null); L+D 9ZE]
List items = AMre(lgh
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criteria.setFirstResult(startIndex).setMaxResults #5X535'ze
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(pageSize).list(); n^iq?u
PaginationSupport ps = !g7lJ\B
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new PaginationSupport(items, totalCount, pageSize, QWI)Y:<K/
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startIndex); ~UNK[
return ps; Xkp?)x3~X
} Fk#$@^c@
}, true); *ry}T=
} @0 #JY:"
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public List findAllByCriteria(final c^1tXu|&
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DetachedCriteria detachedCriteria){ 7m4*dBTr
return(List) getHibernateTemplate ^m['VK#?
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().execute(new HibernateCallback(){ v3b+Ddp
publicObject doInHibernate "'74GY8,
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(Session session)throws HibernateException { <Uc?#;%Y}
Criteria criteria = A)_HSIVi
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detachedCriteria.getExecutableCriteria(session); txik{' :
return criteria.list(); Q 6n!u;
} 5m2f\^U
}, true); yJ4ZB/ZQ
} 1ne3CA=
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public int getCountByCriteria(final gy Ey=@L
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DetachedCriteria detachedCriteria){ |B
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Integer count = (Integer) 2ElZ&(RZJF
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getHibernateTemplate().execute(new HibernateCallback(){ L;-V Yo#
publicObject doInHibernate *WfQi8
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(Session session)throws HibernateException { 5?q6g
Criteria criteria = g'AxJ
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detachedCriteria.getExecutableCriteria(session); $!$,cKPl5
return e}+Zj'5
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criteria.setProjection(Projections.rowCount #$
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()).uniqueResult(); x~Dj2F ]
} hp`ZmLq/[
}, true); bXSAZWf
return count.intValue(); /gn!="J
} i5aY{3!
} @H8DGeM
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用户在web层构造查询条件detachedCriteria,和可选的 0xY</S
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 O7p=N8 V
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PaginationSupport的实例ps。 VeSQq
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ps.getItems()得到已分页好的结果集 <_c8F!K)T
ps.getIndexes()得到分页索引的数组 fW[ .Q0
ps.getTotalCount()得到总结果数 d^f rKPB
ps.getStartIndex()当前分页索引 J;=T"C&
ps.getNextIndex()下一页索引 #qFY`fVf1
ps.getPreviousIndex()上一页索引 Ra"hdxH
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 uXk]
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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 &36SX<vZ
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一下代码重构了。 6']HmM
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我把原本我的做法也提供出来供大家讨论吧: C}(@cn `L
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首先,为了实现分页查询,我封装了一个Page类: s<rV1D
java代码: .!Pg)|
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/*Created on 2005-4-14*/ Ij$C@hH
package org.flyware.util.page; aZ+><1TD
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/** 2:_6nWl
* @author Joa WN<g _8QR
* ^5.XQ0n
*/ Bp3E)l
publicclass Page { 5mC"8N1)
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/** imply if the page has previous page */ xDGS`o_w_
privateboolean hasPrePage; bMGn&6QiP[
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/** imply if the page has next page */ fx(h fz
privateboolean hasNextPage; ^lAM /
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/** the number of every page */ jn:_2g[
privateint everyPage; z9*e%$+S
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/** the total page number */ y TD4{ L%T(H<