Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 QnX(V[
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 VTHH&$ZNq
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 sds"%]rg
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 42ivT_H
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分页支持类: 1D!<'`)AY
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java代码: WvZ8/T'x
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package com.javaeye.common.util; l0i^uMS
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import java.util.List; )B8$<sv
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publicclass PaginationSupport { xWQ`tWA:J
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publicfinalstaticint PAGESIZE = 30; \mlqO[ S
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privateint pageSize = PAGESIZE; ,L'zRyP
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privateList items; Q#[9|A9
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privateint totalCount; fZA4q0
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privateint[] indexes = newint[0]; c6]D-YNFG
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privateint startIndex = 0; 3I-MdApT
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public PaginationSupport(List items, int "OnGE$
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totalCount){ $5Ff1{
setPageSize(PAGESIZE); ))'<_nD
setTotalCount(totalCount); ~zNAbaC+>t
setItems(items); XAL1|]S
setStartIndex(0); iTU5l5U z
} fkNbS
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public PaginationSupport(List items, int I"7u2"@-8j
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totalCount, int startIndex){ l"]}Ts#
setPageSize(PAGESIZE); P3 ^Y"Pv?
setTotalCount(totalCount); w}cPs{Vi"
setItems(items); j]/RC(;?
setStartIndex(startIndex); fMyti$1~
} oIj#>1~c%
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public PaginationSupport(List items, int '}bgLv
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totalCount, int pageSize, int startIndex){ nt7.?$
setPageSize(pageSize); 9j:"J` '
setTotalCount(totalCount); C#Iybg
setItems(items); )gy!GK
setStartIndex(startIndex); HEc+;O1<
} X1vd'>
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publicList getItems(){ M} v/tRI
return items; |64~K\X
} YcK|.Mq':
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publicvoid setItems(List items){ F;0}x;:>
this.items = items; s>n)B^64W
} Ng>h"H
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publicint getPageSize(){ >%8KK|V{
return pageSize; =]Jd9]vi
}
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publicvoid setPageSize(int pageSize){ Q%mB|i|
this.pageSize = pageSize; ':m,)G5&
} ly3\e_z:G
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publicint getTotalCount(){ Y,t={HiclX
return totalCount; ,0HRAmG
} F,)%?<!I
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publicvoid setTotalCount(int totalCount){ __GqQUQ
if(totalCount > 0){ VUR |OV%
this.totalCount = totalCount; |02gup qqi
int count = totalCount / i|*)I:SHU
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pageSize; \<TXS)w]
if(totalCount % pageSize > 0) G..aiA
count++; 0o*8#i/)!3
indexes = newint[count]; 6- B|Y3)B
for(int i = 0; i < count; i++){ !lc[
indexes = pageSize * +<3XJ7D
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} ?\s+EE&-
}else{ /9pwZ%:<
this.totalCount = 0; !fR3(=oN
} +8d1|cB"
} vbe|hO""
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publicint[] getIndexes(){ G@jZ)2
return indexes; :~N-.#
} ly_HWuFJ3
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publicvoid setIndexes(int[] indexes){ Bj-:#P@
this.indexes = indexes; _k~KZ;l
} l &5QZI0I
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publicint getStartIndex(){ A='N=^Pm
return startIndex; y^v6AM
} 0rG^,(3m
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publicvoid setStartIndex(int startIndex){ D}8[bWF
if(totalCount <= 0) 8MzVOF{"
this.startIndex = 0; )@Yf]qx+Y<
elseif(startIndex >= totalCount) mtmjZP(w
this.startIndex = indexes Y^}Z>
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[indexes.length - 1]; w\i\Wp,FP
elseif(startIndex < 0) (w/T-*
this.startIndex = 0; Xe:jAkDp
else{ Df<xWd2
this.startIndex = indexes (I{rLS!o,L
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[startIndex / pageSize]; K<qk.~
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}
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} 27O|).yKX
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publicint getNextIndex(){ F{~{Lthc
int nextIndex = getStartIndex() + ,UGRrS
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pageSize; bITPQ7+
if(nextIndex >= totalCount) KZ
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return getStartIndex(); ,J^b0@S
else "h a L
return nextIndex; dj7hx"BI
} 6GSI"M6s
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publicint getPreviousIndex(){ %9N7Ln|%
int previousIndex = getStartIndex() - i}mVQ\j5
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pageSize; 2Mvrey)
if(previousIndex < 0) F9E<K]7K
return0; Bb^;q#S1
else +|'c>,?2H
return previousIndex; _Wp{[TH
} b#toM';T
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} eWtZ]kB
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抽象业务类 9m<jcxla$
java代码: PHXZ=A+
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/** Q$1bWUS&
* Created on 2005-7-12 Raxrb=7
*/ iAa.}CI,zB
package com.javaeye.common.business; gVv>9W('
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import java.io.Serializable; =`:K{loxq
import java.util.List; 1V4s<m>#
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import org.hibernate.Criteria; .
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import org.hibernate.HibernateException; MgOR2,cR
import org.hibernate.Session; YY)s p%
import org.hibernate.criterion.DetachedCriteria; S=<}:#;u0
import org.hibernate.criterion.Projections; 1#*a:F&re
import M/ni6%x
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org.springframework.orm.hibernate3.HibernateCallback; v~V5`%
import Vq5k+3W+
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org.springframework.orm.hibernate3.support.HibernateDaoS L,`Lggq-
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upport; q<[_T
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import com.javaeye.common.util.PaginationSupport; WD2]&g
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public abstract class AbstractManager extends D@|W<i-
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HibernateDaoSupport { UXugRk%d
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privateboolean cacheQueries = false; dC$Em@Nb
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privateString queryCacheRegion; XZJ+h,f
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publicvoid setCacheQueries(boolean Q6AC(n@:FV
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cacheQueries){ L
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this.cacheQueries = cacheQueries; Rhz_t@e
} W?aI|U1
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publicvoid setQueryCacheRegion(String n'01Hh`0
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queryCacheRegion){ V7[zAq
this.queryCacheRegion = LbG_ z =A
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queryCacheRegion; jbu8~\"
} 8p9bCE>\
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publicvoid save(finalObject entity){ j>x-"9N
getHibernateTemplate().save(entity); T[uiPs/xD
} !z<%GQ CT
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publicvoid persist(finalObject entity){ lR[qqFR
getHibernateTemplate().save(entity); =%gRW5R%
} Y"Ql!5=
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publicvoid update(finalObject entity){ #hf
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getHibernateTemplate().update(entity); \2}bi:e6
} 5ish\"
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publicvoid delete(finalObject entity){ @t`Xq1
getHibernateTemplate().delete(entity); gk+h8 LZ
} }!/$M\w
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publicObject load(finalClass entity, BV(8y.H
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finalSerializable id){ r'uGWW"w
return getHibernateTemplate().load $dzy%lle
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(entity, id); 9}uW}yJ
} )\be2^p
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publicObject get(finalClass entity,
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finalSerializable id){ +$(2:S*r
return getHibernateTemplate().get K+8-9$w6
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(entity, id); [],1lRYI9_
} 13%t"-@bh
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publicList findAll(finalClass entity){ MpqZH{:?G
return getHibernateTemplate().find("from z=_Ef3`M
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" + entity.getName()); OhmQ,
} 199]W Hc
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publicList findByNamedQuery(finalString X*Dj[TD]
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namedQuery){ UybW26C;aU
return getHibernateTemplate _uKZ Ml
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().findByNamedQuery(namedQuery); f1)x5N
} V$icWu
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publicList findByNamedQuery(finalString query, 5qkH|*Z3
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finalObject parameter){ ;w-qHha
return getHibernateTemplate {W~q
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().findByNamedQuery(query, parameter); V8wKAj
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} B Ma)O
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publicList findByNamedQuery(finalString query, ~+bGN
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finalObject[] parameters){ ^1x*lLf
return getHibernateTemplate npyAJp
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().findByNamedQuery(query, parameters); ls `,EFF
} ym/fFm6h
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publicList find(finalString query){ %#Z/2<_
return getHibernateTemplate().find lR`'e0Lq
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(query); h:)Ci!D;
} ,\d6VBP&
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publicList find(finalString query, finalObject (?kl$~&|
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parameter){ ]cC[-F[
return getHibernateTemplate().find -;XKcS7Ue
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(query, parameter); u!U"N*Y"
} (j"(
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public PaginationSupport findPageByCriteria q
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(final DetachedCriteria detachedCriteria){ bo=ZM9
return findPageByCriteria !.<T"8BUpv
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); $RwB_F
} oi&Wo'DX
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public PaginationSupport findPageByCriteria omf Rs
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(final DetachedCriteria detachedCriteria, finalint yag}fQ(XH
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startIndex){ 3q:{1rc
return findPageByCriteria m&0"<V!H/B
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(detachedCriteria, PaginationSupport.PAGESIZE, /DO/Tqdfe
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startIndex); ^t*x*m8
} !lmWb-v%36
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public PaginationSupport findPageByCriteria 9H]Lpi^OH
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(final DetachedCriteria detachedCriteria, finalint h2;z4
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pageSize, O^I[
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finalint startIndex){ }2r+%V&4
return(PaginationSupport)
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getHibernateTemplate().execute(new HibernateCallback(){ l
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publicObject doInHibernate "%QD{z_L
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(Session session)throws HibernateException { v)kEyX'K2d
Criteria criteria = aSYs_?&.
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detachedCriteria.getExecutableCriteria(session); &MgeYpd
int totalCount = !sA_?2$
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((Integer) criteria.setProjection(Projections.rowCount Vjm_F!S
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()).uniqueResult()).intValue(); W;Jx<-#1
criteria.setProjection HT_TP q
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(null); [$(R#tZ+
List items = cQZ652F9
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criteria.setFirstResult(startIndex).setMaxResults bv
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(pageSize).list(); 2vKx]w
PaginationSupport ps = >1irSUj"~
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new PaginationSupport(items, totalCount, pageSize, AzpV4(:an.
$ 'QdFkOr
startIndex); ]&i+!$N_
return ps; 7TX,T|>9
} VLg
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}, true); *Wb=WM-.
} )yb+M ez
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public List findAllByCriteria(final 6=PiVwI
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DetachedCriteria detachedCriteria){ VAYb=4lt
return(List) getHibernateTemplate .Nx
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().execute(new HibernateCallback(){ lg:y|@Y''
publicObject doInHibernate fRg=!<#%
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(Session session)throws HibernateException { Oz:ZQ M
Criteria criteria = yNJAWM7
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detachedCriteria.getExecutableCriteria(session); =O{~Q3z@s
return criteria.list(); 'CS.p!Z\
} NyI;v=
}, true); XqR{.jF.
} r.FLGDU
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public int getCountByCriteria(final ^,2c-
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DetachedCriteria detachedCriteria){ L,-u.vV
Integer count = (Integer) JAn1{<Ky
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getHibernateTemplate().execute(new HibernateCallback(){ G\Q9IcJ0dY
publicObject doInHibernate ^^$vR[7
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(Session session)throws HibernateException { .Tm- g#
Criteria criteria = [7"}=9
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;
detachedCriteria.getExecutableCriteria(session); ZZ
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return i@<~"~>]7
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criteria.setProjection(Projections.rowCount j+748QAhh
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()).uniqueResult(); %7`d/dgR
} Wm6dQQ;Bj
}, true); )hL^+Nn bR
return count.intValue(); !J.rM5K
} d0C8*ifFO
}
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用户在web层构造查询条件detachedCriteria,和可选的 &?$\Y,{
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 B {i&~k
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PaginationSupport的实例ps。 g+Ph6W
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ps.getItems()得到已分页好的结果集 uU+s!C9r
ps.getIndexes()得到分页索引的数组 O=O(3Pf>
ps.getTotalCount()得到总结果数 -"Gl
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ps.getStartIndex()当前分页索引 8)Tj
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ps.getNextIndex()下一页索引 BpXEK.Xw
ps.getPreviousIndex()上一页索引 mW$ot.I
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 t61'LCEis
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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 h2}am:%mC
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一下代码重构了。 ~iT{8
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我把原本我的做法也提供出来供大家讨论吧: fle0c^ =
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首先,为了实现分页查询,我封装了一个Page类: U5wTGv4S|
java代码: jg^^\n
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/*Created on 2005-4-14*/ uf0^E3H
package org.flyware.util.page; V9$-twhu
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/** >#i $Tw
* @author Joa 8c?8X=|D7
* Alh?0 Fk3)
*/ vj@V
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publicclass Page { ) hPVX()O!
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/** imply if the page has previous page */ %~(~W>^A
privateboolean hasPrePage; n1`T#%e
9t\
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/** imply if the page has next page */ &1$8q0
privateboolean hasNextPage; }-@I#9
/kb$p8!C".
/** the number of every page */ lvig>0:M
privateint everyPage; G\IocZ3Gz
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/** the total page number */ iDvpXn
privateint totalPage; h&'J+b
|=OpzCs
/** the number of current page */ b2%blQgo
privateint currentPage; "]9_Fv
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/** the begin index of the records by the current S%P3ek>3
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query */ 6NKF'zh
privateint beginIndex; 8|_K
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/** The default constructor */ Uc>LFX&
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public Page(){ \Em-.%c
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} F_~6n]Sr
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/** construct the page by everyPage 92NC]_jw
* @param everyPage BfEx'C
* */ FRD<0o /`
public Page(int everyPage){ zh
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this.everyPage = everyPage; A<