Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 dZ\T@9+j+
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 *JVJKqed
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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 r5&?-G
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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 9R4q^tGR\
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。 ]BBjFs4#
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分页支持类: ^Xslj
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java代码: JP 8v2)
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package com.javaeye.common.util; S;S_<GX
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import java.util.List; eh$T
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publicclass PaginationSupport { 8 9f{8B]z
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publicfinalstaticint PAGESIZE = 30; ;EfREfk
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privateint pageSize = PAGESIZE; )"<:Md$7
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privateList items; {NV=k%MTmi
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privateint totalCount; xr-v"-
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privateint[] indexes = newint[0]; JKs&!!
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privateint startIndex = 0; M \3Zj(E/
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public PaginationSupport(List items, int XJi^gT N
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totalCount){ l&v&a!EU
setPageSize(PAGESIZE); .R{P%r
setTotalCount(totalCount); B!z5P"C(~
setItems(items); }4"T#
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setStartIndex(0); F#XzhDs
} e5fzV.' 5
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public PaginationSupport(List items, int lDhuL;9e
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totalCount, int startIndex){ Iw) 'Yyg
setPageSize(PAGESIZE); qluaop
setTotalCount(totalCount); HCKj8-*
setItems(items); viR-h
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setStartIndex(startIndex); <3c|S_|L*m
} k/V:QdD Sb
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public PaginationSupport(List items, int "WHt9 yZ
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totalCount, int pageSize, int startIndex){ bO?Us
setPageSize(pageSize); C\p _
setTotalCount(totalCount);
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setItems(items); `=cOTn52
setStartIndex(startIndex); m;KD@E!
} IEW[VU)
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publicList getItems(){ 0^rDf
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return items; QAh6!<.;@
} j#)K/`
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publicvoid setItems(List items){ 4EDwZR>./
this.items = items; Qcr-|?5L
} G[5z3
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publicint getPageSize(){ RP4P"m(
return pageSize; I<ta2<h
} AVbGJ+
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publicvoid setPageSize(int pageSize){ kI>PaZ`i)
this.pageSize = pageSize; ThSB\
} (}LLk+
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publicint getTotalCount(){ Ykd< }KE>
return totalCount; =HkB>w)h
} x4vowF
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publicvoid setTotalCount(int totalCount){ !c8hER!
if(totalCount > 0){ /NFcIU
this.totalCount = totalCount; l TRQ/B
int count = totalCount / )w++cC4/5
:=K <2
pageSize; byUstm6y
if(totalCount % pageSize > 0) B)4>:j:{?W
count++; VaRP+J}UA.
indexes = newint[count]; N/&t)7
for(int i = 0; i < count; i++){ 41V}6+$g
indexes = pageSize * +Qe"O0
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i; VDP \E<3"
} ]DO"2r
}else{ sAz]8(Fi0
this.totalCount = 0; Ki:.^
} ,HE +|y#
} 5b^`M
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publicint[] getIndexes(){ MKN],l
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return indexes; 9xm' 0 '
}
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publicvoid setIndexes(int[] indexes){ ir ^XZVR
this.indexes = indexes; wNgS0{}&`
} *N#{~
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publicint getStartIndex(){ oH|<(8efD
return startIndex; zn@yt%PCV
} +(|6Wv
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publicvoid setStartIndex(int startIndex){ E}WO?xxv74
if(totalCount <= 0) $m-rn'Q
this.startIndex = 0; CAl]Kpc
elseif(startIndex >= totalCount) n@Ar%%\
this.startIndex = indexes 5==}8<$
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[indexes.length - 1]; ,[{)4J$MV
elseif(startIndex < 0) y.:Z:w6$
this.startIndex = 0; b0_Ih6
else{ EecV%E
this.startIndex = indexes C{8d^SCA"
x)<Hr,wd
[startIndex / pageSize]; R~R ?0aq
} KLn.vA.
} ;{k`nv_6
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publicint getNextIndex(){ N=oWIK<;-
int nextIndex = getStartIndex() + `:I<Jp
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pageSize; pjP
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if(nextIndex >= totalCount) ,y57tY
return getStartIndex(); jw"]U jub
else 3 O)^Hq+9
return nextIndex; c)tG1|Og]
} voHFU#Z$
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publicint getPreviousIndex(){ Cd"iaiTD0
int previousIndex = getStartIndex() - cj!Ew}o40D
g}B|ZRz+{
pageSize; @m=xCg.Z
if(previousIndex < 0) PnKgUJoa0
return0; _26<}&]b*
else Tl9;KE|
return previousIndex; fv",4L
} XOe8(cXa9
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} L/VlmN_v>s
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抽象业务类 ^atX/
java代码: cN5,\I.
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/** $bd&$@sA
* Created on 2005-7-12 azxGUS_i<
*/ #Wz7ju;
package com.javaeye.common.business; w)hH8jx{
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import java.io.Serializable; EC4RA'Bg1k
import java.util.List; .qcIl)3
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import org.hibernate.Criteria; Q3$AL@".
import org.hibernate.HibernateException; jx3J$5
import org.hibernate.Session; cBO.96ZHE
import org.hibernate.criterion.DetachedCriteria; &pCNOHi|
import org.hibernate.criterion.Projections; XPhC*r
import nYcj6?
_^ 2rRz
org.springframework.orm.hibernate3.HibernateCallback; hw@ `Q@
import #]iSh(|8
6 Ch
[!=p{
org.springframework.orm.hibernate3.support.HibernateDaoS DO #!ce
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upport; |Mj2lZS
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import com.javaeye.common.util.PaginationSupport; FG^Jh5
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public abstract class AbstractManager extends c?;YufH'j
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HibernateDaoSupport { }J~
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privateboolean cacheQueries = false; _7h:NLd
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privateString queryCacheRegion; <@DF0x!
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publicvoid setCacheQueries(boolean xIN&>D'|N
vnNX)$f
cacheQueries){ P9Yw\
this.cacheQueries = cacheQueries; 0~(K@U>#
} YTc
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publicvoid setQueryCacheRegion(String yZ_6yJw3}
}, < dGmkx
queryCacheRegion){ @2LpI*]C
this.queryCacheRegion = s\)0f_I
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queryCacheRegion; 7wivu*0
} Md4hd#z
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publicvoid save(finalObject entity){ mzh8<w?ns
getHibernateTemplate().save(entity); {<~oa+"
} $S_xrrE#
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publicvoid persist(finalObject entity){ :7,j%ELic
getHibernateTemplate().save(entity); rjFIK`_w
} XYi-o][Mf
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publicvoid update(finalObject entity){ e5g# a}
getHibernateTemplate().update(entity); A&d67,&B
} 4O TuX!
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publicvoid delete(finalObject entity){ ZU=omRh5
getHibernateTemplate().delete(entity); xppl6v(
} 9;\a|8O
K}vP0O}
publicObject load(finalClass entity, DLigpid
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finalSerializable id){ fEdp^oVg
return getHibernateTemplate().load eSqKXmH[m
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(entity, id); 3Kx&+
} =bx;TV
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publicObject get(finalClass entity, #2/2Xv
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finalSerializable id){ |ODi[~y
return getHibernateTemplate().get FZvh]ZX
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(entity, id); BHNcE*U}@?
} b"DV8fdX
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publicList findAll(finalClass entity){ .T2P%Jn.
return getHibernateTemplate().find("from pR3@loFQ`o
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" + entity.getName()); m-<"`:+
} wM-I*<L>
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publicList findByNamedQuery(finalString DOsQVdH
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namedQuery){ tdCD!rV`{
return getHibernateTemplate TFQX}kr]
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().findByNamedQuery(namedQuery); C[-M
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} M,R**z
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publicList findByNamedQuery(finalString query, XZew$Om[
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finalObject parameter){ ,QZNH?Cp/
return getHibernateTemplate xV+cX*4h
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().findByNamedQuery(query, parameter); *@-a{T}
} ~1g)4g~
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publicList findByNamedQuery(finalString query, -n#fj;.2_
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finalObject[] parameters){ j3$\+<m]
return getHibernateTemplate Ae3=o8p
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().findByNamedQuery(query, parameters); i[r>^U8O
} $Ao
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publicList find(finalString query){ -S6^D/(;
return getHibernateTemplate().find 0\DlzIO
yq]/r=e!k
(query); g5>c-i
} 47yzI-1H+
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publicList find(finalString query, finalObject C?-_8OA
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parameter){ .cCB,re
return getHibernateTemplate().find tFrNnbmlQ
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(query, parameter); *{1]b_<
} Cu-z`.#}R
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public PaginationSupport findPageByCriteria u[b0MNE~
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(final DetachedCriteria detachedCriteria){ zLS=>iLD{
return findPageByCriteria rpn&.#KS
- D^.I
(detachedCriteria, PaginationSupport.PAGESIZE, 0); YLkdT%
} y|h:{<
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public PaginationSupport findPageByCriteria \ x>#bql+
227 Z6#CF!
(final DetachedCriteria detachedCriteria, finalint /`H{n$
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startIndex){ bQBYzvd
return findPageByCriteria yh{Wuz=T
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(detachedCriteria, PaginationSupport.PAGESIZE, m`B.3
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startIndex); bG&vCH;}%
} c8}jO=/5+
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public PaginationSupport findPageByCriteria A>Y!d9]ti
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(final DetachedCriteria detachedCriteria, finalint dePI&z:
2& ZoG%)
pageSize, ?I}0[+)V
finalint startIndex){ NWt5)xl
return(PaginationSupport) Ou,Eu05jt'
& 8'QD~
getHibernateTemplate().execute(new HibernateCallback(){ y>iot e~
publicObject doInHibernate ^,,lo<d_L
_ H$^m#h
(Session session)throws HibernateException { y1*z,"dx
Criteria criteria = GkYD:o=qx
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detachedCriteria.getExecutableCriteria(session); S/H!a:_5r
int totalCount = 3lo.YLP^
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((Integer) criteria.setProjection(Projections.rowCount S1G=hgF_L
~ s# !\Ye
()).uniqueResult()).intValue(); le.(KgRS4
criteria.setProjection bc ;(2D
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(null); 3E`poE
List items = |C_sP,W
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criteria.setFirstResult(startIndex).setMaxResults VSQxlAGk@
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(pageSize).list(); &XH{,fv$
PaginationSupport ps = S)~Riuy$
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new PaginationSupport(items, totalCount, pageSize, ^ Z~'>J
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startIndex); _?J:Z*z?
return ps; oMer+=vH
} x"xtILrI
}, true); Sh2;^6d
} J2P5<
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public List findAllByCriteria(final =sa bJsgL
dt=5 Pnf[y
DetachedCriteria detachedCriteria){ dX>l"))yR
return(List) getHibernateTemplate tW7*(D
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().execute(new HibernateCallback(){ =`y.L5
publicObject doInHibernate *3r{s'm
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(Session session)throws HibernateException { "i3Q)$"S
Criteria criteria = FdVWj
5 $a
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detachedCriteria.getExecutableCriteria(session); )Og,VXEB
return criteria.list(); KtY_m`DY4R
} ecl$z6'c
}, true); IsjD-t
} \/
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public int getCountByCriteria(final %U$PcHOo
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DetachedCriteria detachedCriteria){ q,H
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Integer count = (Integer)
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getHibernateTemplate().execute(new HibernateCallback(){ zZ\2fKrpg
publicObject doInHibernate A! j4;=}
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(Session session)throws HibernateException { q<` g
Criteria criteria = Q?\rwnW?U
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detachedCriteria.getExecutableCriteria(session); l<l6Ey(
return eE'2B."F
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criteria.setProjection(Projections.rowCount gbJz5EEq
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()).uniqueResult(); U]h5Q.<SG
} !ENb \'>J>
}, true); ?MhY;z`=
return count.intValue(); |Skxa\MI
} L>qLl_.
} 1vF^<{%v
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用户在web层构造查询条件detachedCriteria,和可选的 utz!ElzA
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 L*VO2YI
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PaginationSupport的实例ps。 tE: m&
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ps.getItems()得到已分页好的结果集 fEl,jA
ps.getIndexes()得到分页索引的数组 4Fr\=TX
ps.getTotalCount()得到总结果数 fem>WPvG
ps.getStartIndex()当前分页索引 ~Z'3(n*9
ps.getNextIndex()下一页索引 ^dzg'6M
ps.getPreviousIndex()上一页索引 K8l|qe
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 U&D"fM8
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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 }cL9`a9j
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一下代码重构了。 ~ZSP K;D[
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我把原本我的做法也提供出来供大家讨论吧: _:,:U[@Vz
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首先,为了实现分页查询,我封装了一个Page类: )bqfj>%#c
java代码: /Wh}
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/*Created on 2005-4-14*/ yB7=8 Pcx
package org.flyware.util.page; 'y
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/** 62&(+'$n
* @author Joa Ew=8"V`C
* 1r?<1vh:z
*/ |8$x
publicclass Page { \S)\~>.`y!
aIv>X@U}
/** imply if the page has previous page */ 5_@8g+~
privateboolean hasPrePage; McgTTM;E
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/** imply if the page has next page */ _91g=pM
privateboolean hasNextPage; 8xQ5[Ov
zUM;Qwl
/** the number of every page */ *N .f_s
privateint everyPage; (>x4X@b
=8r%zLDw
/** the total page number */ 3hOiHO
;
privateint totalPage; DHO6&8S
jB*%nB*x
/** the number of current page */ ZkW,
privateint currentPage; ThX%Uzd"[;
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/** the begin index of the records by the current *v[WJ"8@
:h
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query */ P"J(O<(1-:
privateint beginIndex; 4|uh&4"*@W
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/** The default constructor */ yVvO!
public Page(){ [a;U'v*
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} Vf#X[$pc/
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/** construct the page by everyPage #YM5P
* @param everyPage ,F7W_f#
@3
* */ bb#F2r4
public Page(int everyPage){ hHsCr@i
this.everyPage = everyPage; _uuxTNN0x*
} \ %Er%yv)
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/** The whole constructor */ X !g"D6'
public Page(boolean hasPrePage, boolean hasNextPage, 1D03Nbh|5
\`\& G-\
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int everyPage, int totalPage, .eAN`-t;
int currentPage, int beginIndex){ |1zoT|}q
this.hasPrePage = hasPrePage; PpD ?TAlA
this.hasNextPage = hasNextPage; 6fhH)]0
this.everyPage = everyPage; 0Zp)
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this.totalPage = totalPage; Amf
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this.currentPage = currentPage; t@[&8j2B>
this.beginIndex = beginIndex; D.zEE-cGyb
} Vv4w?K
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/** =B g
* @return a9C8Q
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* Returns the beginIndex. bT<if@h-
*/ n}MW# :eJe
publicint getBeginIndex(){ Yy6Mkw7X
return beginIndex; )-q#hY
} dd#=_xe
\jDD=ew
/** ufE;rcYE
* @param beginIndex XBE+O7
* The beginIndex to set. A*jU&3#
*/ M=$
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publicvoid setBeginIndex(int beginIndex){ zdFO&YHTw
this.beginIndex = beginIndex; V9*Z
} VMPBM:kG
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/** ,U+y)w]ar
* @return @:\Iw"P
* Returns the currentPage. U|QLc
*/ 4.:2!Q
publicint getCurrentPage(){ a>x3UVf_
return currentPage; u}ULb F
} 9P;}P!W
q(sEN!^L`
/** P` Hxj> {
* @param currentPage InnjZ>$
* The currentPage to set. @j*K|+X"
*/ (3Hz=k_
publicvoid setCurrentPage(int currentPage){ R57>z`;
this.currentPage = currentPage; @> n7
} |
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/** D#}t)$"
* @return \ vj<9ke&
* Returns the everyPage. -`nQa$N-
*/ xE.K
publicint getEveryPage(){ NUBf>~_}
return everyPage; -j1?lY
} Vmq:As^a
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/** w U".^
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* @param everyPage ]X
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* The everyPage to set.
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*/ {cmY`to
publicvoid setEveryPage(int everyPage){ <d89eV+
this.everyPage = everyPage; ~9%L)nC2'
} _m .u@+g
DX>Yf}
/** VfWU-lJ
* @return /J''`Tf
* Returns the hasNextPage. LpCJfQ
*/ a"7zz]XO2
publicboolean getHasNextPage(){ WzD=Ol
return hasNextPage; 1iNq|~
} ZfM DyS$.
}8
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/** j#:IG/)GL
* @param hasNextPage 7A6Qrfw
* The hasNextPage to set. (QS4<J"
*/ 8t)5b.PS
publicvoid setHasNextPage(boolean hasNextPage){ .V~z6
this.hasNextPage = hasNextPage; L=g(w$H
} W:5uoO]=<
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/** @ sLb=vb
* @return UAleGR`,
* Returns the hasPrePage. &CP]+ at
*/
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publicboolean getHasPrePage(){ d$DNiJ ,
return hasPrePage; EWz,K]_'
} <}Hfu-PLo
1jHugss9|
/** p>Z18
* @param hasPrePage g$X4ZRSel
* The hasPrePage to set. b&wyp@k
*/ KZeaM
publicvoid setHasPrePage(boolean hasPrePage){ ^w|D^F=o
this.hasPrePage = hasPrePage; :pz`bFJk
} s=KK)6T
O4`am:@
/** b}&2j3-n,
* @return Returns the totalPage. UdGa#rcNW
* 0eJqDCmH
*/ "~V|p3
publicint getTotalPage(){ || p>O
return totalPage; ''p7!V?
} prypo.RI
0c{-$K}
/** q>X30g
* @param totalPage JWB3;,S
* The totalPage to set. AFM Ip^F
*/ dd?ZQ:n
publicvoid setTotalPage(int totalPage){ _P].Z8
this.totalPage = totalPage; IA6,P>}N
} "}|&eBH^<
+"yt/9AO
} $3yzB9\a"
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上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 D MzDV _
2)-V\:;js
个PageUtil,负责对Page对象进行构造: V1l9T_;f
java代码: K>a@AXC
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/*Created on 2005-4-14*/ wC&+nS1
package org.flyware.util.page; v%
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import org.apache.commons.logging.Log; aG*Mj;J
import org.apache.commons.logging.LogFactory; +uqP:z
F/
si =%
/** 5w9oMM{
* @author Joa :Vnus
@#r
* T[(4z@d`5
*/ :qAF}|6
publicclass PageUtil { BN]{o(EB
7 'B9z/
privatestaticfinal Log logger = LogFactory.getLog $ca>bX]
Id}@
(PageUtil.class); 6+.8nx:9X
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/** j&y>?Y&Sb
* Use the origin page to create a new page wJ>.I<F6B
* @param page ^J-"8%
* @param totalRecords PSB@yV <
* @return =@\Li)Y
*/ nqv#?>Z^OT
publicstatic Page createPage(Page page, int h0c&}kM
fU^6h`t
totalRecords){ `mp3ORR;$
return createPage(page.getEveryPage(), Y I?4e7Z+
dN)@/R^E;
page.getCurrentPage(), totalRecords); :c/](M
} o0B3G
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5
/** BpR#3CfW
* the basic page utils not including exception )4O* D92
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handler `21$e
* @param everyPage G5Z_[Q~z
* @param currentPage j0(+Kq:J
* @param totalRecords
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* @return page #U?=D/
*/ nq,P.~l
publicstatic Page createPage(int everyPage, int d>bS)
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currentPage, int totalRecords){ z$]HZ#aRE
everyPage = getEveryPage(everyPage); p6*|)}T_%
currentPage = getCurrentPage(currentPage); Kc#42C;t/
int beginIndex = getBeginIndex(everyPage, .!2Ac
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currentPage); mA" 82"
int totalPage = getTotalPage(everyPage, JANP_b:t
XJ*W7HD
totalRecords); :ySQ[AJ"
boolean hasNextPage = hasNextPage(currentPage, F7N4qq1
-guVl4 V
totalPage); ;e#bl1%#
boolean hasPrePage = hasPrePage(currentPage); I]jK]]@
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returnnew Page(hasPrePage, hasNextPage, tLc~]G*\`s
everyPage, totalPage, 2nv-/%]
currentPage, X)^&5;\`
\CK f/:"
beginIndex); a";xG,U
} !<AY0fpY
g|
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privatestaticint getEveryPage(int everyPage){ KOP*\\1
J
return everyPage == 0 ? 10 : everyPage; EwuBL6kN
} eT ZQ[qMp
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privatestaticint getCurrentPage(int currentPage){ $@}\T
return currentPage == 0 ? 1 : currentPage; ufc_m4PN
} KX $Q`lM
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privatestaticint getBeginIndex(int everyPage, int 2I
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currentPage){ $ 8WJ$73
return(currentPage - 1) * everyPage; f^D4aEU
} C+<z;9`
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privatestaticint getTotalPage(int everyPage, int $P7G,0-
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totalRecords){ lk. ;
int totalPage = 0; }rbsarG@
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if(totalRecords % everyPage == 0) BdYl
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totalPage = totalRecords / everyPage; > qDHb'
else "YQ%j+
totalPage = totalRecords / everyPage + 1 ; ^{(i;IVG
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return totalPage; VQ]MJjvb
} .0H!B#9
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privatestaticboolean hasPrePage(int currentPage){ ,`nl";Zc
return currentPage == 1 ? false : true; qW(_0<E
} $KGpcl
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privatestaticboolean hasNextPage(int currentPage, }N}\<RG
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int totalPage){ AXOR<Ns`
return currentPage == totalPage || totalPage == @[] A&)B
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0 ? false : true; G ?&T0
} e) x;3r"j
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} OcLFVD=
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上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 9b}AZ]$
xB&6f")
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 .wv!;
va_TC!{;
做法如下: lS:R##
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 B>TI dQ
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的信息,和一个结果集List: &ivPY
java代码: }bxx]rDl
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/*Created on 2005-6-13*/ GP/Gv
package com.adt.bo; Y><")% Q
*;I F^u1
import java.util.List; >RMp`HxDf
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import org.flyware.util.page.Page; > =Z@)PAe
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/** /Vy8%
* @author Joa .O+qtk!
*/ U.@j!UrZ
publicclass Result { yfD)|lK
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private Page page; 6c/Tm0[
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private List content; H#joc0?P
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/** G)E#wh_S^
* The default constructor Y}C~&Ph