Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 1{-W?n
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 up~l4]b+
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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 FRicHs n
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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)|m
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分页支持类: <:u)C;
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java代码: N.q4Ar[x#p
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package com.javaeye.common.util; yiUJ!m
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import java.util.List; #4{f2s[j6
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publicclass PaginationSupport { 6 qK0G$>
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publicfinalstaticint PAGESIZE = 30; p;VqkSQ76
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privateint pageSize = PAGESIZE; xa#:oKF3
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privateList items; yKO84cSl
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privateint totalCount; o_gpBaWD
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privateint[] indexes = newint[0]; s
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privateint startIndex = 0; R0fZ9_d7}
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public PaginationSupport(List items, int .ukP)rGe
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totalCount){ 0>-l {4srs
setPageSize(PAGESIZE); l%"eQ
setTotalCount(totalCount); `}F=Zjy
setItems(items); twx8TQ9
setStartIndex(0); ij6M E6
} Y. yM 1 z
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public PaginationSupport(List items, int \PzC:H
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totalCount, int startIndex){ `X]-blHo
setPageSize(PAGESIZE); F'Fc)9qFa<
setTotalCount(totalCount); WjGv%^?
setItems(items); J%xp1/=2
setStartIndex(startIndex); .9WUp>
} |rf\]3 F
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public PaginationSupport(List items, int hX=+%^c%_A
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totalCount, int pageSize, int startIndex){ h^$>{0"
setPageSize(pageSize); B| %=<1?
setTotalCount(totalCount); eF"7[_+D
setItems(items); 1,W%t\D
setStartIndex(startIndex); "Q+'lA[}
} 3l>P>[<o
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publicList getItems(){ Tm_vo-
return items; E]_lYYkA
} &I?1(t~hT
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publicvoid setItems(List items){ 96vv85g
this.items = items; 3OFv_<6
} ;4F[*VF!w
<HG~#oBRq
publicint getPageSize(){ m0F-[k3)
return pageSize; `S<uh9/
} (H+'sf^h
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publicvoid setPageSize(int pageSize){ YFLWkdqAY
this.pageSize = pageSize; -MHu BgYJ-
}
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publicint getTotalCount(){ [}lv!KmzW
return totalCount; e?L$RY,7
} i(,R$AU
v{=-#9-4
&
publicvoid setTotalCount(int totalCount){ Q%QpG)E
if(totalCount > 0){ X!,Ngmw.
this.totalCount = totalCount; 4cJ7.Pez
int count = totalCount / %dL|i2+*8
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pageSize; _J
if(totalCount % pageSize > 0) X\$|oiR
count++; [ne4lWaE<y
indexes = newint[count]; -.g5|B
for(int i = 0; i < count; i++){ cY#TH|M
indexes = pageSize * ~AK!_EOs`
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i; d&?B/E^
} /Rk5n
}else{ fdd3H[
this.totalCount = 0; K(6=)
} &J"a` l2
} N3r{|Bu
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publicint[] getIndexes(){ gNLjk4H,S[
return indexes; X^9_'T9
} pPh_p@3I
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publicvoid setIndexes(int[] indexes){ &r DOqj
this.indexes = indexes; 66)@4 3V
} TmX~vZ
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publicint getStartIndex(){ o?p) V^7
return startIndex; }tv-
} gMI%z2]'-
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publicvoid setStartIndex(int startIndex){ 7GK| A{r
if(totalCount <= 0) qg.[M*
this.startIndex = 0; ! h&hPY1
elseif(startIndex >= totalCount) _vU,avw
this.startIndex = indexes ,=o q)Fm]
.# j)YG
[indexes.length - 1]; 5/P?@`/eT
elseif(startIndex < 0) S*#y7YKI
this.startIndex = 0; 30<dEoF
else{ "-<u.$fE
this.startIndex = indexes o{UwUMw5`
4sZ^:h,1
[startIndex / pageSize]; R"O9~s6N
} L?9Vz&8]
} m>NRIEA6
HSK^vd?_l
publicint getNextIndex(){ X[Y!=e4z
int nextIndex = getStartIndex() + ]vT
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pageSize; VIi|:k
if(nextIndex >= totalCount) L1rov
return getStartIndex(); msY"Y*4
else Vaq=f/
return nextIndex; V!}, a@>p
} 'd6hQ4Vw4
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publicint getPreviousIndex(){ =$BgIt
int previousIndex = getStartIndex() - tvb hWYe
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pageSize; <o?qpW$,>
if(previousIndex < 0) YT:<AJm
return0; qU2>V
else m"x~Fjvd
return previousIndex; %],.?TS2V
} ' R=o,=
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} NoYu"57\
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抽象业务类 ARU,Wtj#
java代码: e2B~j3-?z
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/** M
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* Created on 2005-7-12 MQG$J!N
*/ NqF-[G<
package com.javaeye.common.business; mup3ua]!
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import java.io.Serializable; 8d$~wh
import java.util.List; *$l8H[
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import org.hibernate.Criteria; dOiy[4s
import org.hibernate.HibernateException; IRS^F;)
import org.hibernate.Session; }qlz^s
import org.hibernate.criterion.DetachedCriteria; =e._b 7P
import org.hibernate.criterion.Projections; YKM(qh2
import {L4^IKI
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org.springframework.orm.hibernate3.HibernateCallback; {g
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import g|r
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org.springframework.orm.hibernate3.support.HibernateDaoS `DA=';>Y
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upport; M6X f}>
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import com.javaeye.common.util.PaginationSupport; <#R7sco'
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public abstract class AbstractManager extends ekAGzu
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HibernateDaoSupport { np>*O }r*
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privateboolean cacheQueries = false; ;G\rhk
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privateString queryCacheRegion; A6UtpyS*'
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publicvoid setCacheQueries(boolean 0cS.|\ZTA
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cacheQueries){ [yVU
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this.cacheQueries = cacheQueries; <B``/EX^
} u?'X%'K*
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publicvoid setQueryCacheRegion(String 4< H-ol
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queryCacheRegion){ 94lmsE
this.queryCacheRegion = 49kY]z|"w
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queryCacheRegion; gXfAz,
} `o*eL Lk
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publicvoid save(finalObject entity){ %
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getHibernateTemplate().save(entity); g@EKJFjl
} z&t6,0q`5
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publicvoid persist(finalObject entity){ @\q~OyV
getHibernateTemplate().save(entity); YWdlE7 y
} (PB|.`_<H
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publicvoid update(finalObject entity){ )8N/t6Q
getHibernateTemplate().update(entity); @ ?%"nK
} i2!{.*.
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publicvoid delete(finalObject entity){ K8RloDjk_A
getHibernateTemplate().delete(entity); uV\=EDno
} vu#:D1/BB
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publicObject load(finalClass entity, C<7J5
! TRiFD
finalSerializable id){ %-SP
return getHibernateTemplate().load ~&qe"0
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(entity, id); ca`=dwe>
} --/ .
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publicObject get(finalClass entity, O;zW'*c+
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finalSerializable id){ qxrOfsh
return getHibernateTemplate().get S_WY91r
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(entity, id); sy#Gb#=#
} yqYX<<!V
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publicList findAll(finalClass entity){ =kCpCpET
return getHibernateTemplate().find("from 9\n}!{@i
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" + entity.getName()); >\i{,F=U7
} 0-#ct1-
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publicList findByNamedQuery(finalString Y}[r`}={
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namedQuery){ FUOvH85f
return getHibernateTemplate N0Y!
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().findByNamedQuery(namedQuery); UnMDdJ\
} LTCjw_<7
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publicList findByNamedQuery(finalString query, md2kZ.5u
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finalObject parameter){ %Wu8RG}
return getHibernateTemplate MdKZH\z/
Ay_<?F+&
().findByNamedQuery(query, parameter); Gm%[@7-
} K0#tg^z5d
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publicList findByNamedQuery(finalString query, 'nLv0.7*
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finalObject[] parameters){ jBQQ?cA
return getHibernateTemplate 2V0R|YUt
f[ v??^
().findByNamedQuery(query, parameters); f Xq e7[
} 61KJ(
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publicList find(finalString query){ yQW\0&a$
return getHibernateTemplate().find `=>Bop)
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(query); )I<.DN&
} Jw^+t)t
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publicList find(finalString query, finalObject X >**M
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parameter){ fvx0]of
return getHibernateTemplate().find V&>7i9lEz
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(query, parameter); N7;2BUIXJ
} M-Js"cB[
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public PaginationSupport findPageByCriteria <FJ#Hy+
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(final DetachedCriteria detachedCriteria){ bw[!f4~
return findPageByCriteria >i.+v[)#
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); m1<B6*iG"
} B%t^QbU #\
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public PaginationSupport findPageByCriteria Fivv#4YO
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(final DetachedCriteria detachedCriteria, finalint g5"g,SFGr
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startIndex){ (PNvv/A
return findPageByCriteria 8O7JuR
'"TBhisky
(detachedCriteria, PaginationSupport.PAGESIZE, 99eS@}RC
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startIndex); l(`w]=t&
} bT;C8i4b\H
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public PaginationSupport findPageByCriteria ^NCH)zK]v
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(final DetachedCriteria detachedCriteria, finalint -{w&ya4X
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pageSize, wS5hXTb"
finalint startIndex){ pUPb+:^R
return(PaginationSupport) <ya3|ycnS
*7R3EUUk
getHibernateTemplate().execute(new HibernateCallback(){ kSJWQ
publicObject doInHibernate fT@#S}t
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(Session session)throws HibernateException { ecFI"g
Criteria criteria = o0/03O
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detachedCriteria.getExecutableCriteria(session); z[';HJ0O;
int totalCount = ZNUV Bi
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((Integer) criteria.setProjection(Projections.rowCount YcGqT2oLP
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()).uniqueResult()).intValue(); A6sBObw;
criteria.setProjection tSm|U<
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(null); p$ko=fo-*_
List items = S:5Nh^K
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criteria.setFirstResult(startIndex).setMaxResults ,4\vi|
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(pageSize).list(); HU'd/5fun
PaginationSupport ps = @wg*~"d
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new PaginationSupport(items, totalCount, pageSize, $HH(8NoL
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startIndex); >S~ #E,Tg
return ps; >GjaA1,
} FVSz[n
}, true); _W!g'HP-D
} qBpY3]/
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public List findAllByCriteria(final $0wl=S
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DetachedCriteria detachedCriteria){ `@`CZg
return(List) getHibernateTemplate ('gjfl
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().execute(new HibernateCallback(){ 9(iJ=ao (
publicObject doInHibernate pymT-
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(Session session)throws HibernateException { 6=& wY
Criteria criteria = KctD=6
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detachedCriteria.getExecutableCriteria(session); [A3hrSw
return criteria.list(); $<yb~z7J
} /,;9hx
}, true); Bf7RW[ -v
} fg,~[%1
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public int getCountByCriteria(final R~tv?hP
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DetachedCriteria detachedCriteria){ 9M7{.XR,
Integer count = (Integer) g<,|Q5bK
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getHibernateTemplate().execute(new HibernateCallback(){ eag$i.^aS
publicObject doInHibernate ! g}9xIL
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(Session session)throws HibernateException { R
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Criteria criteria = 7?A}qmv
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detachedCriteria.getExecutableCriteria(session); {g);HnmPN
return o30PI
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criteria.setProjection(Projections.rowCount hwO]{)%
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()).uniqueResult(); GWhb@K
} S</"^C51J
}, true); ]=pEs6%O3
return count.intValue(); U%KoG-#
} XjX<?W
} E`'+1
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用户在web层构造查询条件detachedCriteria,和可选的 -m__I U
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 CUYp(GU
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PaginationSupport的实例ps。
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ps.getItems()得到已分页好的结果集 #4|?;C)u\
ps.getIndexes()得到分页索引的数组 9,9( mbWJv
ps.getTotalCount()得到总结果数 fs`<x*}K
ps.getStartIndex()当前分页索引 xXyzzr1[
ps.getNextIndex()下一页索引 jm*v0kNy
ps.getPreviousIndex()上一页索引 k1%Ek#5
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 MLp5Y\8*
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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 d$>1 2>>
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一下代码重构了。 Et7AAV*8g
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我把原本我的做法也提供出来供大家讨论吧: {^N=hI
QALMF rWH
首先,为了实现分页查询,我封装了一个Page类: air{1="<-
java代码: +]AE}UXZoh
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/*Created on 2005-4-14*/ yCQpqh
package org.flyware.util.page; Qs4Jl ;Y _
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/** >w
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* @author Joa >u6kT\|^C
* iedoL0#
*/ :qnRiK]
publicclass Page { JM M\
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/** imply if the page has previous page */ jCy2bE
privateboolean hasPrePage; D@f%&|IZ
Z&PwNr/
/** imply if the page has next page */ 578Dl(I#)
privateboolean hasNextPage; jIEK[vJ`
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/** the number of every page */ TpnkJygIm
privateint everyPage; T$k) ^'
=JEnK_@?K\
/** the total page number */ 0$P40 7
privateint totalPage; 0w\gxd~'
n RXf \*"3
/** the number of current page */ (3_2h4O
privateint currentPage; E]+W^VG
!WrUr]0IP
/** the begin index of the records by the current V&qXsyg
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query */ y/Nvts2!C
privateint beginIndex; Z|3l2ucl
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/** The default constructor */ fOrqY,P'
public Page(){ n /rQ*hr
mWO=(}Fb\
} w8>p[F5`O
X, J.!:4`
/** construct the page by everyPage [5:F
* @param everyPage CjIkRa@!x
* */ Prr<:q
public Page(int everyPage){ a-O9[?G/x
this.everyPage = everyPage; c?[A
} A 8&%G8d
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/** The whole constructor */ F[Peil+|`
public Page(boolean hasPrePage, boolean hasNextPage, A87Tyk2Pi
20hE)!A
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int everyPage, int totalPage, 0;V2>!
int currentPage, int beginIndex){ C[wnor!
this.hasPrePage = hasPrePage; Vrz<DB^-e
this.hasNextPage = hasNextPage; #E*jX-JT
this.everyPage = everyPage; >6(nW:I0y
this.totalPage = totalPage; `yc.A%5
this.currentPage = currentPage; 3~M8.{
U#V
this.beginIndex = beginIndex; $yOfqr
} Kx#G_N@
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/** Is-Kz}4L
* @return UD"e:O_
* Returns the beginIndex. h/PWi<R
i
*/ #XNe4#
publicint getBeginIndex(){ T|oz_c\e
return beginIndex; "i9$w\lm
} u\>Ed9^
wGw}a[a
/** F4d L{0;j
* @param beginIndex O4(
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* The beginIndex to set. t t#M4n@
*/ Lt=#tu&d
publicvoid setBeginIndex(int beginIndex){ Cm>8r5LG
this.beginIndex = beginIndex; U<o,`y[Tn
} 00<iv"8
,]Hn*\@p[c
/** l6)*u[}E
* @return q}(UC1|
* Returns the currentPage. TB1 1crE
*/ {s4:V=J
publicint getCurrentPage(){ [|uAfp5R
return currentPage; u:fiil$
} 6`F_js.a
{8b6A~/
/** !t[X/iu
* @param currentPage 1\_4# @')
* The currentPage to set. 4uDz=B+8y
*/ c1e7h l
publicvoid setCurrentPage(int currentPage){ U
= T[-(:H
this.currentPage = currentPage; sL[,J[AN;
} t5[{ihv~:
hm?-QVRPV
/** dH?;!sJ
* @return b Kv9F@
* Returns the everyPage. k1B7uA'h"G
*/ |jc87(x<
publicint getEveryPage(){ AVHn7olG
return everyPage; Kkdd }j
} L,Uqt,
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/** u'LA%l-
* @param everyPage Pp#!yMxBr
* The everyPage to set. Jg|/*Or
*/ aRg-
rz
publicvoid setEveryPage(int everyPage){ aY8>#t?
this.everyPage = everyPage; Y~bp:FkS
} }_XKO\
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/** 'szkn0
* @return Ow mI*`
* Returns the hasNextPage. L}x"U9'C
*/ ;k!bv|>n
publicboolean getHasNextPage(){ >:h
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return hasNextPage; aCy2.Qn
} naM4X@jl
+g\u=&<6
/** N!r@M."
* @param hasNextPage xlS
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* The hasNextPage to set. ~ia#=|1}
*/ a)[t kjU
publicvoid setHasNextPage(boolean hasNextPage){ 0;r+E*`DA
this.hasNextPage = hasNextPage; - C8h$P
} (F~eknJ
T?NwSxGo
/** Y!CZ?c)@
* @return "k5 C? ~
* Returns the hasPrePage. ?OlYJ/!z3
*/ LYv+Sv
publicboolean getHasPrePage(){ <-X)<k
return hasPrePage; u!X[xe;
} ]%F3 xzOk
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/** qvhTc6oH
* @param hasPrePage Kl\A&O*{
* The hasPrePage to set. cM.q^{d`
*/ ^cBA8 1
publicvoid setHasPrePage(boolean hasPrePage){ xw]Zo<F
this.hasPrePage = hasPrePage; ?Tt/,Hl?D
} [m!$01=
Wvmf[!V;
/** 2u/(Q>#
* @return Returns the totalPage. s%;18V:pi
* x>p=1(L
*/ jHTaG%oh
publicint getTotalPage(){ s
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return totalPage; C`7HC2Is
} 6HFA2~A
bG;vl;C
/** l*xA5ObV
* @param totalPage u*}6)=+:
* The totalPage to set. B5P++aQ
*/ Z9 }qds6 y
publicvoid setTotalPage(int totalPage){ sm4@ywd>
this.totalPage = totalPage; NM
} |&h!#Q{7l
$A8eMJEpL
} c;BQ$je}
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#](ML:!
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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 wW]|ElYR=
oI/@w
个PageUtil,负责对Page对象进行构造: *
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java代码: ?r2Im5N
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/*Created on 2005-4-14*/ SL>>]A,E<`
package org.flyware.util.page; >c8zMd
VBBqoyP
h
import org.apache.commons.logging.Log; "?}QwtUW
import org.apache.commons.logging.LogFactory; GVCyVt[!-
Et# }XVCJ
/** ir3iW*5k
* @author Joa Jel%1'Dc^
* 1h"0B
*/ VS1gg4tCv
publicclass PageUtil { z| i$eF;x3
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jM&9
privatestaticfinal Log logger = LogFactory.getLog laKMQLtv
4VD'<`R[
(PageUtil.class); ezC55nm
^5QSV\X
/** VCkhK9(N
* Use the origin page to create a new page jFbz:aUF
* @param page t.485L%
* @param totalRecords @_h/%>0
* @return nYTI\f/8v
*/ =r:D]?8oC
publicstatic Page createPage(Page page, int f+-w~cN
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totalRecords){ /M\S^!g@
return createPage(page.getEveryPage(), &.K=,+0_R/
/,c9&it(M
page.getCurrentPage(), totalRecords); m 9.QGX\]
} (y=P-nm
6n45]?
/** 6TlkPM$~2
* the basic page utils not including exception 'hg, W]
ib;:*
handler c]t=#
* @param everyPage +q1
@8
* @param currentPage
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* @param totalRecords /XtxgO\T.
* @return page xAon:58m{
*/ )TVyRY Z1
publicstatic Page createPage(int everyPage, int {6a";Xj\e
z^ KrR
currentPage, int totalRecords){ }7wQFKME
everyPage = getEveryPage(everyPage); c3g\*)Jz"F
currentPage = getCurrentPage(currentPage); X;6&:%ZL@^
int beginIndex = getBeginIndex(everyPage, g>T'R Vb
[[LCEw
currentPage); xH; 4lw
int totalPage = getTotalPage(everyPage, MpGWt#
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totalRecords); J:M^oA'N:>
boolean hasNextPage = hasNextPage(currentPage, P_lk40X
*~:4&$
totalPage); {*yhiE ,
boolean hasPrePage = hasPrePage(currentPage); &HT
PeB
*"q ~z
returnnew Page(hasPrePage, hasNextPage, gMFTZQsP
everyPage, totalPage, <?2[]h:wp
currentPage, 0Eo*C9FP~
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beginIndex); wvBJ?t,
} !H~G_?Mf\O
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privatestaticint getEveryPage(int everyPage){ h8$lDFo
return everyPage == 0 ? 10 : everyPage; DLJu%5F
} rP^2MH"
zG+oZ
privatestaticint getCurrentPage(int currentPage){ &NB[:S=
return currentPage == 0 ? 1 : currentPage; Ag#p )
} W5HC7o\4
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privatestaticint getBeginIndex(int everyPage, int maXQG&.F
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currentPage){ (VU: &.
return(currentPage - 1) * everyPage; ;~tKNytD`B
} dHg[0Br)r
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privatestaticint getTotalPage(int everyPage, int o%RyE]pw,
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totalRecords){ B
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int totalPage = 0; AdKv!Ta5b
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if(totalRecords % everyPage == 0) ko=vK%E[
totalPage = totalRecords / everyPage; gM^ Hs7o,
else {6 C!^ 5
totalPage = totalRecords / everyPage + 1 ; _LCK|H%v'
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return totalPage; -jFvDf,M,D
} &,3.V+Sz
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privatestaticboolean hasPrePage(int currentPage){ cQA;Y!Q#
return currentPage == 1 ? false : true; k`'^e/
} D)K/zh)
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privatestaticboolean hasNextPage(int currentPage, ./rNq!*a
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int totalPage){ I[c/)
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return currentPage == totalPage || totalPage == T%VC$u4F
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0 ? false : true; qI5_@[S*
} 6zaO$
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} wS hsu_(i
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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。 K*d+pImrV
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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 Pz:,q~
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做法如下: "6FZX~]s!
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Kn?>XXAc
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的信息,和一个结果集List: S)>L 0^M1
java代码: ;mjk`6p
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/*Created on 2005-6-13*/ Z[[qW
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package com.adt.bo; )4bBR@QM
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import java.util.List; "fU=W|lY
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import org.flyware.util.page.Page; v8I&~_b
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/** XBh0=E?qiS
* @author Joa h'|{@X
*/ 2ed$5.D
publicclass Result { kD8$ir'UYG
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private Page page; Rr{mD#+
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private List content; F;kY5+a7~e
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/** ^mv F%"g
* The default constructor W.'#pd
*/ !9_HZ(W&
public Result(){ wa\Yc,R
super(); }~DlOvsq
} 8iGS=M
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/** RXxi7^ U
* The constructor using fields
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* iP]KV.e'/C
* @param page - 0R5g3^*/
* @param content #^|y0:
*/ EZ:pcnL{
public Result(Page page, List content){ ?
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this.page = page; 3CL/9C>
this.content = content; C&