Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Haktr2I
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 FNF `Z
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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
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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 #;^U W
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分页支持类: ;Bz|hB{
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java代码: EwV$2AK
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package com.javaeye.common.util; \a|~#N3?
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import java.util.List; bsU$$;
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publicclass PaginationSupport { SZ[?2z
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publicfinalstaticint PAGESIZE = 30; ?K:\WW
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privateint pageSize = PAGESIZE; 8/tB?j
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privateList items; j_}:=3
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privateint totalCount; E8#aE\'t
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privateint[] indexes = newint[0]; s6!&4=ZA
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privateint startIndex = 0; G]k[A=dg
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public PaginationSupport(List items, int uQdy
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totalCount){ D>W&#A8&y
setPageSize(PAGESIZE); 80Fa i
setTotalCount(totalCount); XPMUhozV
setItems(items); \C>IVz<O
setStartIndex(0); wH@S$WT
} [@VzpVhXz
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public PaginationSupport(List items, int @Z'i7Z
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totalCount, int startIndex){ 8r+u!$i!H
setPageSize(PAGESIZE); !xR9I0V5
setTotalCount(totalCount); ibQ
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setItems(items); +kYp!00
setStartIndex(startIndex); ]k]bLyz\J
} B1~`*~@
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public PaginationSupport(List items, int 8g_kZ^<[
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totalCount, int pageSize, int startIndex){ %au>D
setPageSize(pageSize); O-UA2?N@j
setTotalCount(totalCount); ;DnUeE8
setItems(items); 5;/q[oXI
setStartIndex(startIndex); }2RbX,0l9
} 7"aN7Q+EbI
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publicList getItems(){ |?^qsnB
return items; Ieq_XF]U
} }ixCbuD
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publicvoid setItems(List items){ Nk\ni>Du3
this.items = items; ,ps?@lD
} /"A=Yf
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publicint getPageSize(){ 9RJ#zUK
return pageSize; T}Wbt=\M
} 9<3}zwJ
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publicvoid setPageSize(int pageSize){ iZnLgkk@
this.pageSize = pageSize; Jv3G\9_
} Gchs$^1`t
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publicint getTotalCount(){ ju[y-am$/
return totalCount; 'JdK0w#
} .,qh,m\Fo
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publicvoid setTotalCount(int totalCount){ ]C"?xy
if(totalCount > 0){ 4l*cX1!
this.totalCount = totalCount; )ej1)RU"
int count = totalCount / Hk4k
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pageSize; Oj%5FUP~[%
if(totalCount % pageSize > 0) 'Y
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count++; x5PM]~"p
indexes = newint[count]; ,Il) t H
for(int i = 0; i < count; i++){ Q wG_-
indexes = pageSize * (fl$$$
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} t`hes
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}else{
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this.totalCount = 0; *u|1Z%XO
} PPG+~.7
} x5\D u63
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publicint[] getIndexes(){ X8*~Cf73u
return indexes; F~rl24F
} Y$,~"$su|
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publicvoid setIndexes(int[] indexes){ ^vSSG5 :
this.indexes = indexes; X)RgXl{
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publicint getStartIndex(){ _0^>^he
return startIndex; K0v S
} YhRy
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publicvoid setStartIndex(int startIndex){ WY@g=W>+
if(totalCount <= 0) YSPUQ
this.startIndex = 0; sx7zRw
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elseif(startIndex >= totalCount) oBub]<.J
this.startIndex = indexes {)b
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[indexes.length - 1]; , :K{
elseif(startIndex < 0) :'q$emtY
this.startIndex = 0; SFwY%2np)!
else{ 0'A"]6
this.startIndex = indexes sxuP"4
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[startIndex / pageSize]; {*8G<&
} =6\^F i
} -\%5aXr
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publicint getNextIndex(){ \@h$|nb
int nextIndex = getStartIndex() + fXnewPr=#
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pageSize; :,qvqh][
if(nextIndex >= totalCount) 3jW&S
return getStartIndex(); 4|cRYZj5
else W<^t2 j'
return nextIndex; *6u2c%^
} YE*|KL^
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publicint getPreviousIndex(){ pQ^V<6z}
int previousIndex = getStartIndex() - RRQv<x
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pageSize; JP( tf+
if(previousIndex < 0) ~bzac2Rp
return0; *m>[\)
else RiQg]3oY
return previousIndex; /|&4&$
} >tMI%r
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} 1VG]|6f
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抽象业务类 :6(@P1vA 6
java代码: yXEI%2~)
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/** >e-0A
* Created on 2005-7-12 w3b?i89
*/ y}={S,z%22
package com.javaeye.common.business; yeIS} O
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import java.io.Serializable; ()t~XQ
import java.util.List; 9 2D~trn
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import org.hibernate.Criteria; :?ZrD,D
import org.hibernate.HibernateException; I!kR:Z
import org.hibernate.Session; Gi@c`lRd1
import org.hibernate.criterion.DetachedCriteria; pNQ7uy
import org.hibernate.criterion.Projections; |Go$z3bx
import s]A8C^;c
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org.springframework.orm.hibernate3.HibernateCallback; 5f0g7w =-
import xbcmvJrG
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org.springframework.orm.hibernate3.support.HibernateDaoS /f oI.S
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upport; W)o*$cu
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import com.javaeye.common.util.PaginationSupport; K(lVAKiP]
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public abstract class AbstractManager extends )ryP K"V
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HibernateDaoSupport { 5{DwD{Q
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privateboolean cacheQueries = false; X6w+L?A
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privateString queryCacheRegion; jxhZOLG
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publicvoid setCacheQueries(boolean j5/|1N
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cacheQueries){ G[_Z|Xi1
this.cacheQueries = cacheQueries; OfA+|xT&
} x\:KfYr4Y;
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publicvoid setQueryCacheRegion(String +`mI\+y,
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queryCacheRegion){ e$Yvy>I'tS
this.queryCacheRegion = fJk'5kv
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queryCacheRegion; ~FXq%-J
} Hdd3n6*
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publicvoid save(finalObject entity){ _"t>72
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getHibernateTemplate().save(entity); cCx{
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} ,-(D(J;}1
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publicvoid persist(finalObject entity){ >/}p{Tj
getHibernateTemplate().save(entity); s!MD8ia
} %WmTG }L)
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publicvoid update(finalObject entity){ XUUP#<,s
getHibernateTemplate().update(entity); BjTgZ98J
} 8~RJnwF^
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publicvoid delete(finalObject entity){ s0x/2z
getHibernateTemplate().delete(entity); [[N${ C
} %" l;
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publicObject load(finalClass entity, lt2MB#
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finalSerializable id){ q*a~9.i@
return getHibernateTemplate().load "VoufXM:
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(entity, id); OkT@ _U
} BE~-0g$W
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publicObject get(finalClass entity, R(P(G;#j
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finalSerializable id){ ;<b7kepR
return getHibernateTemplate().get C#)T$wl[E
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(entity, id); 9~a 5R]x2
} P-8QXDdr
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publicList findAll(finalClass entity){ dmLx $8
return getHibernateTemplate().find("from !yq98I'
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" + entity.getName()); oj'YDQ^uj
} VTyj<6Y
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publicList findByNamedQuery(finalString yxf#@Je"
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namedQuery){ 4UzXTsjM7
return getHibernateTemplate l2dj GZk
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().findByNamedQuery(namedQuery); C6@*l~j
} ^mC,Z+!
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publicList findByNamedQuery(finalString query, FDGG$z?>m
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finalObject parameter){ s&$e}yxVO
return getHibernateTemplate Zv-1*hhHf
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().findByNamedQuery(query, parameter); !)W#|sys&
} ]Ge>S?u
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publicList findByNamedQuery(finalString query, |68/FJZ,5
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finalObject[] parameters){ ObS#aRq
return getHibernateTemplate &uBfsa$
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().findByNamedQuery(query, parameters); Iu >4+6
} co^h2b
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publicList find(finalString query){ aU[!*n 4Ux
return getHibernateTemplate().find =]pEvj9o
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(query); R1<$VR
} e#3RT8u#
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publicList find(finalString query, finalObject )ZrB-(u~k
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parameter){ +qT+iHa|n
return getHibernateTemplate().find 8$ #z>
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(query, parameter); MLmaA3
} ^}wF^ _
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public PaginationSupport findPageByCriteria fH:S_7i
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(final DetachedCriteria detachedCriteria){ T-/3
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return findPageByCriteria FCKyKn
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); 49}WJC7
)
} y*US^HJOZ
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public PaginationSupport findPageByCriteria aD_7^8>
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(final DetachedCriteria detachedCriteria, finalint 9nFWJn
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startIndex){ &%qDi_UD
return findPageByCriteria Tm7LaM
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(detachedCriteria, PaginationSupport.PAGESIZE, b0@K ~O;g
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startIndex); WpnP^gmX
} IA]wO%c
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public PaginationSupport findPageByCriteria Cx.##n0
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(final DetachedCriteria detachedCriteria, finalint -o!bO9vC
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pageSize, l+hOD{F4pS
finalint startIndex){ k%kEW%I yG
return(PaginationSupport) 'd&4MA 0X
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getHibernateTemplate().execute(new HibernateCallback(){ t imY0fx#
publicObject doInHibernate yx:+Xy*N
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(Session session)throws HibernateException { 7n+,!oJ
Criteria criteria = _9p79S<+
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detachedCriteria.getExecutableCriteria(session); -p>1:M <
int totalCount =
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((Integer) criteria.setProjection(Projections.rowCount 1\Pjz
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()).uniqueResult()).intValue(); - _6`0
criteria.setProjection F[!%,-*
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(null); ,Oy$q~.
List items = EBz4k)@m
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criteria.setFirstResult(startIndex).setMaxResults $N;J)
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(pageSize).list(); YPNW%N!$|
PaginationSupport ps = -/0\_zq7
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new PaginationSupport(items, totalCount, pageSize, <mVFC
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startIndex); 1sonDBd0@;
return ps; n00J21
}
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}, true); p|mFF0SL
} (c^ {T)
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public List findAllByCriteria(final 3/yt
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DetachedCriteria detachedCriteria){ {x_cgsn
return(List) getHibernateTemplate i'"#{4I
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().execute(new HibernateCallback(){ *n7=m=%)
publicObject doInHibernate (6:.u.b
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(Session session)throws HibernateException { gH\>",[
Criteria criteria = 748:*
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detachedCriteria.getExecutableCriteria(session); 'd&d"E[
return criteria.list(); CV\y60n
} vTK8t:JQ~
}, true); \b8#xT}
} |O oczYf
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public int getCountByCriteria(final B7|%N=S%/
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DetachedCriteria detachedCriteria){ dJJq]^|
Integer count = (Integer) -o`K/f}d
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getHibernateTemplate().execute(new HibernateCallback(){ y"'p#j
publicObject doInHibernate KF1iYo>p
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(Session session)throws HibernateException { wQjYH!u,YZ
Criteria criteria = #\QW <I#/
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detachedCriteria.getExecutableCriteria(session); I2*(v%.-
return {f)aFGp
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criteria.setProjection(Projections.rowCount dg|x(p#
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()).uniqueResult(); C/qKa[mg
} {Bk` Zlki
}, true); 3\
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return count.intValue();
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} a=A12<
} pI8z.JD
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用户在web层构造查询条件detachedCriteria,和可选的 X1a~l|$h
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 ]BbV\#
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PaginationSupport的实例ps。 mI4GBp
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ps.getItems()得到已分页好的结果集 &dmIv[LU
ps.getIndexes()得到分页索引的数组 :.]EM*p?GV
ps.getTotalCount()得到总结果数 b+J|yM<`
ps.getStartIndex()当前分页索引 *GBV[D[G,
ps.getNextIndex()下一页索引 (@xC-*
ps.getPreviousIndex()上一页索引 ?hc=w 2Ci
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 [7gz?9VyLF
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 [m
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一下代码重构了。 Oy=0Hsh@x
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我把原本我的做法也提供出来供大家讨论吧: f>C+ l(
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首先,为了实现分页查询,我封装了一个Page类: Ib{l$#
java代码: ?&eS }skL
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/*Created on 2005-4-14*/ W$SV+q(rT
package org.flyware.util.page;
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#@`c7SR
/** Ea<\a1Tl43
* @author Joa 9=]HOUn
* [qRww]g;P|
*/ =0Y0o_
publicclass Page { UR_Ty59
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/** imply if the page has previous page */ ^"
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privateboolean hasPrePage; &`n:AR`
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/** imply if the page has next page */ \9#f:8Q
privateboolean hasNextPage; 9v*y&V9/
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/** the number of every page */ 1)
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privateint everyPage; V
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/** the total page number */ =lk'[P/p`
privateint totalPage; ">t^jt{
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/** the number of current page */ [u K,.G
privateint currentPage; ,"#nJC
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/** the begin index of the records by the current )z74,n7-
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query */ O4oN)
privateint beginIndex; y|MhV/P04
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/** The default constructor */ b' M"To@
public Page(){ 2INpo
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} 9ETdO,L)f
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/** construct the page by everyPage x+6z9{O
* @param everyPage 'h6G"=+
* */ O^-QqCZE
public Page(int everyPage){ #'%ii,;wQ
this.everyPage = everyPage; :'ZR!w
} 3-:^mRPJ
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/** The whole constructor */ 3T]cDVQ_
public Page(boolean hasPrePage, boolean hasNextPage, We}9'X}
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int everyPage, int totalPage, M=;csazN
int currentPage, int beginIndex){ G5t7KI
this.hasPrePage = hasPrePage; %_Lz0L64k
this.hasNextPage = hasNextPage; z$%8'
this.everyPage = everyPage; FN!?o:|(
this.totalPage = totalPage; *lLCH,
this.currentPage = currentPage; URm<