Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 -vc$I=b;
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ,JbP~2M~%
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 .X)Wb{7
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 MT)q?NcG
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分页支持类: i|,}y`C#
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java代码: l=Jw6F+5
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package com.javaeye.common.util; i eWXr4@:
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import java.util.List; =oiz@Q @H
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publicclass PaginationSupport { (|<+yQ,@>
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publicfinalstaticint PAGESIZE = 30; iPG:w+G
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privateint pageSize = PAGESIZE; +eKLwM
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privateList items; Sd.Km a
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privateint totalCount; umAO&S.+M
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privateint[] indexes = newint[0]; pStbj`Eq
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privateint startIndex = 0; ei=u$S.
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public PaginationSupport(List items, int %BMlcm7Ec
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totalCount){ 0yMHU[):~
setPageSize(PAGESIZE); %z-s o?gF
setTotalCount(totalCount); 7Lj:m.0O^
setItems(items); ^'Rs`e
setStartIndex(0); 9jx>&MnWs
} M$>Nd6,@N
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public PaginationSupport(List items, int $[Nf?`f(t_
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totalCount, int startIndex){ }vgM$o
setPageSize(PAGESIZE); +;pw^QB
setTotalCount(totalCount); pzQc UG
setItems(items); E[zq<&P@
setStartIndex(startIndex); saQo]6#
} vgg)f~
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public PaginationSupport(List items, int dNqj | Vu
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totalCount, int pageSize, int startIndex){ <pKOFN%m
setPageSize(pageSize); O*]}0*CT
setTotalCount(totalCount); 0(Z:QqpU$
setItems(items); e.XD5~Ax
setStartIndex(startIndex); H.]<fvP
} \LQZoD?W
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publicList getItems(){ QG
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return items; <m{#u4FC'
} k$#1T +(G
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publicvoid setItems(List items){ Eg2jexl
this.items = items; )S`Yl;oL
} v"%>ms"n
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publicint getPageSize(){ -=UvOzw
return pageSize; K9VP@[zbJ
} UMF M.GI
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publicvoid setPageSize(int pageSize){ v/$<#2|
this.pageSize = pageSize; U%#Vz-r
} 4&e<Sc64
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publicint getTotalCount(){ j':<7n/A
return totalCount; Pd
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} xH,e$t#@@~
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publicvoid setTotalCount(int totalCount){ |m*l/@1
if(totalCount > 0){ >lek@euqw
this.totalCount = totalCount; I)r6*|mz
int count = totalCount / e85E+S%
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pageSize; 9q&~!>lt
if(totalCount % pageSize > 0) gF293Ez
count++; Q4S:/"*v8
indexes = newint[count]; /Zx"BSu
for(int i = 0; i < count; i++){ SymlirL
indexes = pageSize * *] >R
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} YbZ?["S&
}else{ d]sg9`
this.totalCount = 0; JL u$UR4
} YT)1_>*\
} Su
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publicint[] getIndexes(){ zNn
return indexes; el<[Ng[
} &Akw V-
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publicvoid setIndexes(int[] indexes){ @q@I(%_`
this.indexes = indexes; 6~?yn-Z
} +I*a=qjq
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publicint getStartIndex(){ 8W7ET@`
return startIndex; dg+"G|nr
} W!=ur,F+
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publicvoid setStartIndex(int startIndex){ am| 81)|a
if(totalCount <= 0) 8 QI+O`
this.startIndex = 0; dV*9bDkM/
elseif(startIndex >= totalCount) 0dD.xuor
this.startIndex = indexes hX-^h2eV
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[indexes.length - 1]; ICG:4n(,
elseif(startIndex < 0) W~l.feW$i
this.startIndex = 0; #0^a-47PA<
else{ N?A}WW#
this.startIndex = indexes :r:x|[3.
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[startIndex / pageSize]; AnZy
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} `J7@G]X;2
} }<'ki
;
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publicint getNextIndex(){ =*6H!bzX
int nextIndex = getStartIndex() + HuN_$aP
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pageSize; (Bpn9}F-V.
if(nextIndex >= totalCount) DD>n-8M@>
return getStartIndex(); <p`
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else Dv^M/z2&[
return nextIndex; k@>(sXs
} )hVn/*mH
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publicint getPreviousIndex(){ n%QWs1 b
int previousIndex = getStartIndex() - K&-uW _0
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} 0_}W
pageSize; w`=XoYQl~*
if(previousIndex < 0) #??[;xjs!
return0; .i#'IS0c
else PbV1FB_
return previousIndex; dn_l#$ U
} q+?q[:nR-
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} z\WyL ;
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抽象业务类 25W #mh,'
java代码: OU?.}qc<wE
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/** G) 37?A)
* Created on 2005-7-12 rfh`;G5s
*/ _ZK*p+u%
package com.javaeye.common.business; I%z,s{9p
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import java.io.Serializable; D|vck1C5,
import java.util.List; X LY>}r
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import org.hibernate.Criteria; gmiLjI
import org.hibernate.HibernateException;
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import org.hibernate.Session; lxR]Bh+
import org.hibernate.criterion.DetachedCriteria; @)ls+}=Y
import org.hibernate.criterion.Projections; _]0<G8|Rv
import YlZ&4
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org.springframework.orm.hibernate3.HibernateCallback; !bn=b>+
import &}#zG5eu
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org.springframework.orm.hibernate3.support.HibernateDaoS hij
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upport; z6Nz)$!_i
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import com.javaeye.common.util.PaginationSupport; "_+8z_
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public abstract class AbstractManager extends \23m*3"W
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HibernateDaoSupport { >YcaFnY
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privateboolean cacheQueries = false; VLbbn
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privateString queryCacheRegion; Fgi;%
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publicvoid setCacheQueries(boolean B @8lD\
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cacheQueries){ PJ<9T3Fa
this.cacheQueries = cacheQueries; #w!ewC vt
} zXIdup@
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publicvoid setQueryCacheRegion(String jK{qw
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queryCacheRegion){ Q-yNw0V}F
this.queryCacheRegion = {m_y<
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queryCacheRegion; 9LSV^[QUH
} ?*~sx=mC
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publicvoid save(finalObject entity){ dleCh+ny?
getHibernateTemplate().save(entity); T^#d\2
} sH%Ts@Pl
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publicvoid persist(finalObject entity){ _C,9c7K4
getHibernateTemplate().save(entity); TRE D_6
} 0W)|n9
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publicvoid update(finalObject entity){ JOwu_%
getHibernateTemplate().update(entity); -\25&m!+
} ;Qq7@(2y
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publicvoid delete(finalObject entity){ [|\#cVWs
getHibernateTemplate().delete(entity); z0|-OCmL
} 6$H`wDh#(&
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publicObject load(finalClass entity, FyNm1QNy^
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finalSerializable id){ @yF>=5z:
return getHibernateTemplate().load -U|Z9sia
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(entity, id); 1'1>B
} ffsF], _J
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publicObject get(finalClass entity, I[n|#N
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finalSerializable id){ ^Iqu ^n?2.
return getHibernateTemplate().get [i_evsUj?
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(entity, id); yqP=6
} x4v&%d=M
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publicList findAll(finalClass entity){ |*l^<= =
return getHibernateTemplate().find("from jrX`_Y
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" + entity.getName()); ;
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} Xi w
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publicList findByNamedQuery(finalString 9I''$DVf
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namedQuery){ Uz%ynH
return getHibernateTemplate Zu94dFP
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().findByNamedQuery(namedQuery); bEmzigN[
}
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publicList findByNamedQuery(finalString query, ;Nd'GA+1;(
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finalObject parameter){ 8fK/0u^`d
return getHibernateTemplate gu&W:FY
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().findByNamedQuery(query, parameter); n3$u9!|P
} 3#eAXIW[
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publicList findByNamedQuery(finalString query, t[MM=6|Wb
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finalObject[] parameters){ {`(MK6D8 c
return getHibernateTemplate S>jOVWB
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().findByNamedQuery(query, parameters); #c~-8=
} R83PHM
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publicList find(finalString query){ K>n@8<7
return getHibernateTemplate().find 7G0;_f{
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(query); mE&SAm5#d
} +Eel|)Z*Q
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publicList find(finalString query, finalObject i(V
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parameter){ sn]D7Ae
return getHibernateTemplate().find QP>F *A
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(query, parameter); qggRS)a
} RLcC>Z
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public PaginationSupport findPageByCriteria A+FQmLS
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(final DetachedCriteria detachedCriteria){ p&D7&Sb[
return findPageByCriteria x6^FpNgQ
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); s4 Vju/
} ,fo7.
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public PaginationSupport findPageByCriteria </R@)_'
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(final DetachedCriteria detachedCriteria, finalint bfkFk
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startIndex){ yV31OBC:
return findPageByCriteria
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(detachedCriteria, PaginationSupport.PAGESIZE, rje;Bf
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startIndex); dTte4lh
} GH&5m44
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public PaginationSupport findPageByCriteria ~RZN+N
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(final DetachedCriteria detachedCriteria, finalint 'z@]hm#
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pageSize, C'jCIL
finalint startIndex){ 2X(2O':Uc
return(PaginationSupport) f 0~Z@\
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getHibernateTemplate().execute(new HibernateCallback(){ w7 \vrS>&
publicObject doInHibernate "W_E!FP]r
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(Session session)throws HibernateException { $-<yX<.
Criteria criteria = k0TQFx.A
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detachedCriteria.getExecutableCriteria(session); Bx.hFEL
int totalCount = "#iO{uMWb
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((Integer) criteria.setProjection(Projections.rowCount e-.(O8
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()).uniqueResult()).intValue(); 8cRc5X
criteria.setProjection 9Vt6);cA-]
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(null); %CgmZTz~<
List items = n7zM;@{7
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criteria.setFirstResult(startIndex).setMaxResults lLK||2d
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(pageSize).list(); 4#I=n~8a
PaginationSupport ps = {}=5uU 2Tu
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new PaginationSupport(items, totalCount, pageSize, !#E-p?O.
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startIndex); D7c+/H@PF
return ps; n*G!=lMji
} C[;7i!Dv
}, true); 8
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} *Tmqs@L
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public List findAllByCriteria(final .mOm@<Xdg
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DetachedCriteria detachedCriteria){ !A14\
return(List) getHibernateTemplate 1k"i"kRM
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().execute(new HibernateCallback(){ B =DV!oUg
publicObject doInHibernate pTJ_DH
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(Session session)throws HibernateException { er>{#8 P
Criteria criteria = .I>CL4_
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detachedCriteria.getExecutableCriteria(session); $lJ!f
return criteria.list(); b0tbS[j
} 7JY9#+?p>
}, true); b'xBPTN
} .RS
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public int getCountByCriteria(final DYew6B-
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DetachedCriteria detachedCriteria){ 9yLPh/!Ob
Integer count = (Integer) s,D GFK
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getHibernateTemplate().execute(new HibernateCallback(){ =Hj3o_g-
publicObject doInHibernate -ilhC Y@M
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(Session session)throws HibernateException { 7mb5z/N
Criteria criteria = m
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detachedCriteria.getExecutableCriteria(session); -'i[/{
return h[C XH"
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criteria.setProjection(Projections.rowCount ]0{,P
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()).uniqueResult(); *6v5JH&K
} w}29#F\]R
}, true); \`8F.oZ^)
return count.intValue(); {4%ddJn[.)
} E>"SC\#7
} "`w*-O
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用户在web层构造查询条件detachedCriteria,和可选的 F<)f&<5E-
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 6$fwpW
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PaginationSupport的实例ps。 4@-Wp]
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ps.getItems()得到已分页好的结果集 1+tPd7U
ps.getIndexes()得到分页索引的数组 ^SwU]e
ps.getTotalCount()得到总结果数 ikPr>
ps.getStartIndex()当前分页索引 J/[PA[Rf
ps.getNextIndex()下一页索引 UG<<.1JL
ps.getPreviousIndex()上一页索引 WkoYkkuzj
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 >rFM8P(
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 *`tQX$F
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一下代码重构了。 ^9|&w.:@Q
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我把原本我的做法也提供出来供大家讨论吧: EhN@;D+
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首先,为了实现分页查询,我封装了一个Page类: >lugHF$G
java代码: X`I=Z ysB
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/*Created on 2005-4-14*/ n$"BF\eM
package org.flyware.util.page; !,*Uvs@b
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/** j9=)^?
* @author Joa v)'Uoe"R%
* EFs\zWF
*/ -}Rh+n`
publicclass Page { N&u(9Fxn
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/** imply if the page has previous page */ m9Dg%\B
privateboolean hasPrePage; "+BuFhSLf
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/** imply if the page has next page */ PS??wlp7
privateboolean hasNextPage; mpl^LF[
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/** the number of every page */ lq27^K
privateint everyPage; W1Om$S1
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/** the total page number */ j,N,WtE
privateint totalPage; I4zm{ 1g
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/** the number of current page */ v/3Vsd
privateint currentPage; U[!wu]HMF
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/** the begin index of the records by the current B 5va4@
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query */ Uql7s:!,U
privateint beginIndex; 8;Df/%
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/** The default constructor */ x4@IK|CE
public Page(){ L4Si0 K
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} vslN([@JR
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/** construct the page by everyPage rE.z.r"O
* @param everyPage cX48?srG
* */ Z`@< O%
public Page(int everyPage){ Pv3 e*I((
this.everyPage = everyPage; [2zS@p
} yrR,7vJ
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/** The whole constructor */ /909ED+)>9
public Page(boolean hasPrePage, boolean hasNextPage, 74%Uojl"
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int everyPage, int totalPage, m?<5-"hz
int currentPage, int beginIndex){ &$_#{?dPt
this.hasPrePage = hasPrePage; 1=Q3WMT
this.hasNextPage = hasNextPage; IZ+ZIR@}ci
this.everyPage = everyPage; {>>Gc2UT
this.totalPage = totalPage; x% Eu.jj
this.currentPage = currentPage; p87VJ}
this.beginIndex = beginIndex; <(2,@_~@r
} 'FGf#l<
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/** |'12Kv]#Xa
* @return </7?puVR
* Returns the beginIndex. 0'^zIL#.
*/ V?Ye^-29
publicint getBeginIndex(){ K#'{Ko
return beginIndex; a(eUdGJ
} hjY)W;
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/** FtxmCIVIV~
* @param beginIndex bA3pDt).p
* The beginIndex to set. JUC62s#_z
*/ ;=?KQq f
publicvoid setBeginIndex(int beginIndex){ Kyq/o-
this.beginIndex = beginIndex; n4Eqm33
} z8n]6FDiE
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/** n/-d56
* @return KdkZ-.
* Returns the currentPage. )I9W a*I
*/ x-ShY&k
publicint getCurrentPage(){ !l1ycQM
return currentPage; 9\W }p\c
} a$'=a09
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