Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 (:E^} &A
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ?]$.3azO
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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 6OIA>%{
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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 gKS^-X{x
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分页支持类: QE-t v00
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java代码: I>ofSaN
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package com.javaeye.common.util; 7xWX:2l*?
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import java.util.List; =B;rj
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publicclass PaginationSupport { js k<N
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publicfinalstaticint PAGESIZE = 30; uXK$5"
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privateint pageSize = PAGESIZE; <0&];5
on
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privateList items; @R`OAdy
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privateint totalCount; #(XP=PUj
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privateint[] indexes = newint[0]; ?i9LqHL
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privateint startIndex = 0; NhpGa@[D
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public PaginationSupport(List items, int &wLI:x5
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totalCount){ V{c
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setPageSize(PAGESIZE); eQzSWn[
setTotalCount(totalCount); JX>_imo
setItems(items); ]sbu9O ^"f
setStartIndex(0); #[Ns\%Ri0
} ZTHrjW1
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public PaginationSupport(List items, int U'Vz
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totalCount, int startIndex){ l|5ss{llR
setPageSize(PAGESIZE); *3.
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setTotalCount(totalCount); mlIc`GSI
setItems(items); =`.9 V<
setStartIndex(startIndex); h9SS
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} b:W]L3Z8
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public PaginationSupport(List items, int /UM9g+Bb
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totalCount, int pageSize, int startIndex){ ]TD]
setPageSize(pageSize); !k%Vw18
setTotalCount(totalCount); hM+nA::w
setItems(items); s)_sLt8?
setStartIndex(startIndex); bzB9u&
} @I_A(cr
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publicList getItems(){ MhJq~G p
return items; 1xcx2L+R
} U4^dDj
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publicvoid setItems(List items){ 7F.>M
this.items = items; #WfJz}P,!
} KHdj#3<AR
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publicint getPageSize(){ $6ITa }o
return pageSize; K Rm4r
} %qN8uQx
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publicvoid setPageSize(int pageSize){ &W|'rA'r
this.pageSize = pageSize; S@Jl_`<
} 85Ms*[g
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publicint getTotalCount(){ )lH?XpfTjm
return totalCount; `(Ei-$
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} 6n;ew l}
@(Q4
publicvoid setTotalCount(int totalCount){ &X +@,!
if(totalCount > 0){ ZtDHNL
this.totalCount = totalCount; U3A>#EV
int count = totalCount / gy~M]u{
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pageSize; 0~BQ8O=+mn
if(totalCount % pageSize > 0) 213D{#2
count++;
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indexes = newint[count]; Fv e,&~
for(int i = 0; i < count; i++){ QDxL y aL
indexes = pageSize * d v@6wp:
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i; !A!zG)Ue<
} uA\A4
}else{ v }P~g
this.totalCount = 0; ;#f_e;
} j:U>V7Kn3~
} h_y<A@[P}
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publicint[] getIndexes(){ h-!(O^M
return indexes; eYR/kZ%<
} C:gE
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publicvoid setIndexes(int[] indexes){ ,3N8
this.indexes = indexes; ZFrK'BvbR
} 2Uu,Vv
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publicint getStartIndex(){ C|z`hNp
return startIndex; ~oSLWA9
} cDE?X o'!
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publicvoid setStartIndex(int startIndex){ =>-b?F0(c
if(totalCount <= 0) "fz-h
this.startIndex = 0; y~U+MtSf#
elseif(startIndex >= totalCount) o&I0*~sN
this.startIndex = indexes /?2yo{Fg
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[indexes.length - 1]; f\/};a
elseif(startIndex < 0) 7_q"%xH
this.startIndex = 0; Uf_w
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else{ a ,W5T8
this.startIndex = indexes "@`M>)*o
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[startIndex / pageSize]; *4A.R&Vu
} `Gsh<.w!7
} t*Lo;]P
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publicint getNextIndex(){ US>
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int nextIndex = getStartIndex() + Uc7X)
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pageSize; AO^F6Y/
if(nextIndex >= totalCount) Y^3tk}yru
return getStartIndex(); X3a:*1N
else b/ZX}<s(1=
return nextIndex; :(I)+;M}P
} @JN%P}4)
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publicint getPreviousIndex(){ dqd Qt_
int previousIndex = getStartIndex() - B%'Np7
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pageSize; QHtpCNTVb
if(previousIndex < 0)
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return0; 5z El`h
else eaF5S'k 4$
return previousIndex; V @d:n
} P[gk9{sv
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} p'xj:bB
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抽象业务类 ,QG,tf?
java代码: Z/Mp=273
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/** yd>kJk^~/
* Created on 2005-7-12 C-4I
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*/ QRt(?96
package com.javaeye.common.business; }14.u&4
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import java.io.Serializable; >E)UmO{S
import java.util.List; /vU9eh"%
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import org.hibernate.Criteria; B=n]N+
import org.hibernate.HibernateException; 14zo0ANM
import org.hibernate.Session; fI}-?@
import org.hibernate.criterion.DetachedCriteria; rEddX
import org.hibernate.criterion.Projections; I-;JDC?
import qD`')=
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org.springframework.orm.hibernate3.HibernateCallback; #Oe=G:+A
import oZOFZ-<
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org.springframework.orm.hibernate3.support.HibernateDaoS p8F|]6Z
pRt )B`#
upport; gvwR16N
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import com.javaeye.common.util.PaginationSupport; uOougSBV,
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public abstract class AbstractManager extends ^Jc~G~x4*
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j_is
HibernateDaoSupport { XtQ3$0{*%
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privateboolean cacheQueries = false; " I _T
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privateString queryCacheRegion; BDB-OJ
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publicvoid setCacheQueries(boolean Uhg[#TUK
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cacheQueries){ 4H\O&pSS
this.cacheQueries = cacheQueries; *NXwllrci
} ;#f%vs>Y7i
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publicvoid setQueryCacheRegion(String *23
q)@.f.
queryCacheRegion){ O`@$YXuD
this.queryCacheRegion = EDnmYaa)dZ
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queryCacheRegion; WpmypkJA#
} "rAm6b-`
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publicvoid save(finalObject entity){ [Q^kO;
getHibernateTemplate().save(entity); w)!(@}vd
} BE3~f6 `
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publicvoid persist(finalObject entity){ c/g(=F__[
getHibernateTemplate().save(entity); y`(z_5ClT
} *w@>zkBl
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publicvoid update(finalObject entity){ MJ92S(
getHibernateTemplate().update(entity); 4@8i,q>
} `w~ 9/sty
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publicvoid delete(finalObject entity){ AY! zXJ_$
getHibernateTemplate().delete(entity); =}Cb?C[;
} }8r+&e
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publicObject load(finalClass entity, "KFCA9u-
<@zOdW|{:
finalSerializable id){ Gjv'$O2_
return getHibernateTemplate().load 9V"^F.>
*b.>pY?2|
(entity, id); ,eZ'pxt
} 6qHo$#iT
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publicObject get(finalClass entity, wx57dm+
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finalSerializable id){ XP(q=Mw
return getHibernateTemplate().get 8PQ$X2)
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(entity, id); Y-,#3%bT;;
} 7Y!^88,f.
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publicList findAll(finalClass entity){ F.@yNr"
return getHibernateTemplate().find("from y ruN5
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" + entity.getName()); %!eK"DKG^
} x"N,oDs
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publicList findByNamedQuery(finalString { !FrI@
_ H@pYMNH
namedQuery){ &"L3U
return getHibernateTemplate y"){?
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().findByNamedQuery(namedQuery); Z#oo8
} moc_}(
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publicList findByNamedQuery(finalString query, rc;| ,\
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finalObject parameter){ G=b`w;oL:
return getHibernateTemplate AE<AEq
hl# 9a?
().findByNamedQuery(query, parameter); d<Z`)hI{K
} \kg2pF[V
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publicList findByNamedQuery(finalString query, 4}NFa;M1
@<w$QD
finalObject[] parameters){ ?.,cWKGQ}
return getHibernateTemplate A\: =p
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().findByNamedQuery(query, parameters); ^pg5o)M
} QU417EV'
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publicList find(finalString query){ sA`
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return getHibernateTemplate().find N>gv!z[E
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(query); HD`Gi0
} R)<>} y
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publicList find(finalString query, finalObject }7&;YAt
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parameter){ jo"[$%0`
return getHibernateTemplate().find DE. Pw+5<.
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(query, parameter); %GHHnf%2Z
} #b{otc)
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public PaginationSupport findPageByCriteria ['sIR+c%'O
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(final DetachedCriteria detachedCriteria){ Z9! goI
return findPageByCriteria y`\/eX
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); al"1T-
} 2o/AH \=2
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public PaginationSupport findPageByCriteria OS \co:
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(final DetachedCriteria detachedCriteria, finalint bggSYhJ?\#
d;'@4NX5+
startIndex){ c| p
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return findPageByCriteria m&;
t;
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(detachedCriteria, PaginationSupport.PAGESIZE, j)J4[j
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startIndex); ss-Be
} e"2 wXd_}
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public PaginationSupport findPageByCriteria ,Q}/#/
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(final DetachedCriteria detachedCriteria, finalint OP<@Xz
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pageSize, Ujw^j
finalint startIndex){ \DfvNeF
return(PaginationSupport) ch< zpo:
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getHibernateTemplate().execute(new HibernateCallback(){ ?+dI/jB4X
publicObject doInHibernate Y6g[y\*t
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(Session session)throws HibernateException { 9K)OQDv%6D
Criteria criteria = |e+I5
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detachedCriteria.getExecutableCriteria(session); aY"qEH7]
int totalCount = JU"!qXQr
bC)<AG@Z\
((Integer) criteria.setProjection(Projections.rowCount LkNfcBa_
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()).uniqueResult()).intValue(); (:@qn+
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criteria.setProjection 2{{M{#}S.
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(null); f2yc]I<lr~
List items = b7"pm)6
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criteria.setFirstResult(startIndex).setMaxResults fC(lY4,H3R
ko ~iDT
(pageSize).list(); )Hw;{5p@
PaginationSupport ps = [q_Yf!(m-
Iy e
new PaginationSupport(items, totalCount, pageSize, `~*qjA
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startIndex); drN^-e
return ps; 8zZR%fZ
} <G6 wpf8M
}, true); <Z#u_:5@
} ~;U!?
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public List findAllByCriteria(final *Z{W,8h*s
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DetachedCriteria detachedCriteria){ sRY: 7>eg
return(List) getHibernateTemplate lr^-
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().execute(new HibernateCallback(){ ?#]c{Tlpz
publicObject doInHibernate >5]Xl*{H)
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(Session session)throws HibernateException { m>UJ; F
Criteria criteria = +IJpqFH
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detachedCriteria.getExecutableCriteria(session); A$|> Jt
return criteria.list(); Npq=jlj
} MA"iM+Ar
}, true); ]>:%:-d6
} 6G1Z"9<2*
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public int getCountByCriteria(final 7b
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DetachedCriteria detachedCriteria){ U6_1L,W
Integer count = (Integer) eW\_9E)cY
ir/ 2/
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getHibernateTemplate().execute(new HibernateCallback(){ ~\XB'
publicObject doInHibernate - FE)
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(Session session)throws HibernateException { ZwG+ rTW
Criteria criteria = |a'Q^aT
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detachedCriteria.getExecutableCriteria(session); i?|K+"=D
return :B"'49Q`
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criteria.setProjection(Projections.rowCount
i 0L7`TB
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()).uniqueResult(); 8l)l9;4 6
} b8QW^Z
}, true); 5%G++oLXf
return count.intValue(); $\a;?>WA"
} Bt.W_p
} =U@*adgw
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用户在web层构造查询条件detachedCriteria,和可选的 i*2z7M Y
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 6bqJM#y@
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PaginationSupport的实例ps。 SxQ|1:i%
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ps.getItems()得到已分页好的结果集 \ iP[iE=
ps.getIndexes()得到分页索引的数组 zBc7bbK
ps.getTotalCount()得到总结果数 hvpn=0@M
ps.getStartIndex()当前分页索引 %/'[GC'y!
ps.getNextIndex()下一页索引 faJ5f.
ps.getPreviousIndex()上一页索引 ~=#jO0dE|
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 5^%^8o
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 0<>iMr D
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一下代码重构了。 sIELkF?.
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我把原本我的做法也提供出来供大家讨论吧: cHR }`U$
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首先,为了实现分页查询,我封装了一个Page类: 4+ 4?0R
java代码: X>Xpx<RY!
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/*Created on 2005-4-14*/ Jl^oDW
package org.flyware.util.page; 8zpK;+
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/** 4NEk#n
* @author Joa dxASU|Yo9
* TyK;
q{
*/ 6J=~ *&
publicclass Page { fA+M/}=
+{#BQbx6
/** imply if the page has previous page */ Q'\jm=k
privateboolean hasPrePage; $G=\i>R.
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/** imply if the page has next page */ [NKWudq
privateboolean hasNextPage; ?X:RrZ:/
wvq<5gy}
/** the number of every page */ _Juhl^LM;
privateint everyPage; q].C>R*ux8
cBm3|@7
/** the total page number */ tG#F7%+E
privateint totalPage; bz>#}P=58G
esLY1c%"/
/** the number of current page */ Z:n33xh=<
privateint currentPage; AV8TP-Ls+
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/** the begin index of the records by the current ME |"pJ
[ PQG]"
query */ s5z@`M5'm
privateint beginIndex; b,K1EEJ
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! q1Ql18n
/** The default constructor */ 7tr.&A^c
public Page(){ :m+:%keK
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} *&AK.n_
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/** construct the page by everyPage _c #P
* @param everyPage Rd#,Tl\
* */ `[ne<F?e
public Page(int everyPage){ _wqFKj
this.everyPage = everyPage; 1yKf=LZ^
} @B[=`9KF[
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/** The whole constructor */ ,f1+jC
public Page(boolean hasPrePage, boolean hasNextPage, |0Zj/1<$
T&0tW"r?
o= 8yp2vG
int everyPage, int totalPage, fmSA.z
int currentPage, int beginIndex){ 3Yr
this.hasPrePage = hasPrePage; Dljq
this.hasNextPage = hasNextPage; fh 2Pn!h+
this.everyPage = everyPage; ()SG
this.totalPage = totalPage; koie
this.currentPage = currentPage; X'3F79`
this.beginIndex = beginIndex; >%W"u`Q
} I/@Xr
f{b"=hQ
/** "+AeqrYYm5
* @return BS{">lPmx
* Returns the beginIndex. R.RCa$
*/ &0o&!P8CB
publicint getBeginIndex(){ -BjB>Vt
return beginIndex; @cXY"hP`
} 0Ifd!
lOEbh
/** *vj5J"Y(;t
* @param beginIndex (d~'H{q
* The beginIndex to set. ; aMMIp
*/ WFh!re%Z
publicvoid setBeginIndex(int beginIndex){ |epe;/
this.beginIndex = beginIndex; 8p!PR^OM@
} zPVA6~|l
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/** Nd( $s[
* @return BE m%x0y
* Returns the currentPage. <vj&e(D^
*/ I
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publicint getCurrentPage(){ g:*yjj
return currentPage; AU7c =
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} [PU.lRq
7%F9.h
/** _=cMa's
* @param currentPage FB</~
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* The currentPage to set. M2m@N-+R
*/ w)}[)}T!
publicvoid setCurrentPage(int currentPage){ %iX+"
this.currentPage = currentPage; 8
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} =6%0pu]0
Eu0_/{:
/** PVvG
* @return &-{4JSII
* Returns the everyPage. <ZnAPh
*/ t<`BaU
publicint getEveryPage(){ ?HBc7$nW
return everyPage; ?Jx8z`(
} ?= fJu\;
gFW1Nm_DJ
/** PgxU;N7Y
* @param everyPage Oc"2|X
* The everyPage to set. ;1o"Oij
*/ #2`tsZ]=I
publicvoid setEveryPage(int everyPage){ :|d3BuY
this.everyPage = everyPage; b _6j77
} %f^TZ,q$
.]jKuTC\<
/** %]:u ^\7
* @return |m?0h.O,
* Returns the hasNextPage. "q%Q[^b
*/ uEk$Y=p7!
publicboolean getHasNextPage(){ W"~G]a+
return hasNextPage; rK`*v*
} z
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kgA')]
/** ++FMkeHZ
* @param hasNextPage gE%- Pf~
* The hasNextPage to set. =*I>MgCJ
*/ dvUJk<;w
publicvoid setHasNextPage(boolean hasNextPage){ jd$lu^>I
this.hasNextPage = hasNextPage; Iw48+krm>
} {Ynr(J.
p;C`n)7P7
/** 0z%]HlPg
* @return 6>KDK<5NQ
* Returns the hasPrePage. 3s$m0
*/ PDtaL
publicboolean getHasPrePage(){ <Z}2A8mjY
return hasPrePage; @90)
} O1-Ne.$
sKNN ahGjh
/** /y1,w JI
* @param hasPrePage #2n>J'}
* The hasPrePage to set. :r!nz\%WW
*/ ?}O\'Fa8
publicvoid setHasPrePage(boolean hasPrePage){ 7$/ O{GBJ
this.hasPrePage = hasPrePage; k%.IIVRx
} fRq2sK;+
k ELV]iWb
/** Wb^YqqE
* @return Returns the totalPage. p6>3
p
* qex.}[
*/ 3VcG
/rf
publicint getTotalPage(){ I]zCsT.
return totalPage; )|*HkdF`
} QQ pe.oF
;K`qSX;;c(
/** TqzkF7;k4
* @param totalPage yfi.<G)S
* The totalPage to set. )=2iGEVW
*/ cn Q(
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publicvoid setTotalPage(int totalPage){ e)GFJ3sW_
this.totalPage = totalPage; nIdvff
} #knpZ'
^e)KEkh
} qd(`~a
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z$S)|6Q
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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 BQ &|=a6
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个PageUtil,负责对Page对象进行构造: Z^s&]
java代码: mpN|U(n
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# M%-q8
/*Created on 2005-4-14*/ O?rVa:\
package org.flyware.util.page; P!1y@R>Ln
jsH7EhF{'
import org.apache.commons.logging.Log; ]B\H
import org.apache.commons.logging.LogFactory; B`9'COw
n:' Mpux
/** qVE6ROSh
* @author Joa 4IIe1
.{
* -NHc~=m
*/ m)g:@^$
publicclass PageUtil { ^vfp;
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privatestaticfinal Log logger = LogFactory.getLog 3~%9;.I3!
1s/t}J~zZ
(PageUtil.class); 6|~N5E~SX
"Lw[ $
/** ~X)Aw3}F
* Use the origin page to create a new page Z;-=x p
* @param page |*K AqTO0
* @param totalRecords IP9mv`[
* @return hvwKhQ}wX
*/ (TgLCT[@T
publicstatic Page createPage(Page page, int tg.[.vKs
+?DP r
totalRecords){ dXg.[|S*
return createPage(page.getEveryPage(), \mbm$E+X
9jBP|I{xI
page.getCurrentPage(), totalRecords); sZxf.
} .SAOE'Foo
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PB
/** 6Q"fRXM
* the basic page utils not including exception o/t^rY y
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handler j0_)DG
* @param everyPage 4,4S5u[|
* @param currentPage 8Q d *OO
* @param totalRecords qT5q3 A(8
* @return page /g(WCKva
*/ aQzx^%B1
publicstatic Page createPage(int everyPage, int NGIt~"e7R4
' d' Dlg
currentPage, int totalRecords){ (_1(<Jw
everyPage = getEveryPage(everyPage); (#KSwWo{ed
currentPage = getCurrentPage(currentPage); w#0/&\b=
int beginIndex = getBeginIndex(everyPage, YS],o'T
NhG?@N
currentPage); "Tt5cqUQoY
int totalPage = getTotalPage(everyPage, >h)D~U(H
w>S;}[fM
totalRecords); f"9aL= 3
boolean hasNextPage = hasNextPage(currentPage, @:s(L]
^hZZ5(</8P
totalPage); FWC\(f
boolean hasPrePage = hasPrePage(currentPage); wB'GV1|jL
(r*"}"ZG
returnnew Page(hasPrePage, hasNextPage, BLaF++Fop
everyPage, totalPage, V) xwl vX
currentPage, _"l2UDx
T&'p5h=l
beginIndex); [Z]%jABR
} n Nu~)X
|!m8JV|x
privatestaticint getEveryPage(int everyPage){ ExKyjWAJ
return everyPage == 0 ? 10 : everyPage; |-l9 Z
} d#(ffPlq
K]SsEsd
privatestaticint getCurrentPage(int currentPage){ 0q6xXNAX
return currentPage == 0 ? 1 : currentPage; [b :0j-
} tn38T%
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privatestaticint getBeginIndex(int everyPage, int @6"+x
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currentPage){ #W9{3JGUY
return(currentPage - 1) * everyPage; u~8=ikn+T
} zFi)R }Ot
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privatestaticint getTotalPage(int everyPage, int 6c6w w"
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totalRecords){ !&adO,jN+=
int totalPage = 0; 'ws@I?!r
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if(totalRecords % everyPage == 0) oM^VtH=>
totalPage = totalRecords / everyPage; ]P*H,&I`#
else bn:74,GeyK
totalPage = totalRecords / everyPage + 1 ; a9_KoOa.H
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return totalPage; =d BK,/
} ku)/
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privatestaticboolean hasPrePage(int currentPage){ )8E[xBaO
return currentPage == 1 ? false : true; G){A&F
} 9K>~9Za
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privatestaticboolean hasNextPage(int currentPage, (c
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{)I&&fSz
int totalPage){ >r>pM(h
return currentPage == totalPage || totalPage == G0u
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0 ? false : true; q*!Vyk
} XMF#l]P
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} JMfv|>=
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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。 `j4OKZ
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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 mUfANlQ:
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做法如下: Iv{uk$^7S
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 n){u!z)Al
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的信息,和一个结果集List: o,qUf
java代码: -+0!Fkt@,
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/*Created on 2005-6-13*/ nFjaV`6`@
package com.adt.bo; L;U?s2&Y
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import java.util.List; ${tBu#$-d
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import org.flyware.util.page.Page; ahR-^^'$
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/** d z\yP
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* @author Joa &g!yRvM!;Q
*/ p@3 <{kLm
publicclass Result { iwfH~
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private Page page; }O:l]O`
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private List content; U3p Mv|b
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/** Sj;:*jk!h
* The default constructor X1="1{8H
*/ KS;Wr6]@(O
public Result(){ +2m\Sv V
super(); Cdc=1,U(
} \O\veB8
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/** 4Z/]7Ie
* The constructor using fields |Gt]V`4
* {WuUzq`
* @param page #Qd"d3QG
* @param content Gu%}B@ 4^
*/ (y?`|=G-xT
public Result(Page page, List content){ wTn"
this.page = page; )C>M74Bt
this.content = content; b\+9#)Up@
} 41o~5:&
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/** ?r R,
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* @return Returns the content. 9]|G-cyt
*/ Tl*FK?)MC^
publicList getContent(){ KCfcEz
return content; E>rWm_G
} gX]'RBTb
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/** T0BM:ofx
* @return Returns the page. A"T*uv|
*/ T]?QCf
public Page getPage(){ p"q4R2_/jh
return page; tH9BC5+r}
} 5x}OrfDU
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/** UzUt=s!^H
* @param content X-5&c$hv
* The content to set. zqb3<WP"
*/ ,8@U-7f,
public void setContent(List content){ *Ui>NTl
this.content = content; XLFo"f
} R^GLATM
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/** pAdSOR2
* @param page 3o^oq
* The page to set. +7bV
*/ A@OSh6/{h
publicvoid setPage(Page page){ M-NY&