Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 gIR{!'
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 zT|]!',
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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 XDvT#(Pu
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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 1]r+$L3
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分页支持类: CCJ!;d;&87
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java代码: 8H_3.MK
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package com.javaeye.common.util; P%5h!Z2m
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import java.util.List; 'z\K0
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publicclass PaginationSupport { i]Or'L0c
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publicfinalstaticint PAGESIZE = 30; $l:?(&u
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privateint pageSize = PAGESIZE; <Tr_,Ya{9
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privateList items; O&93QN0
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privateint totalCount; H"8+[.xBh
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privateint[] indexes = newint[0]; B[F,D
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privateint startIndex = 0; vB, X)
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public PaginationSupport(List items, int 'j];tO6GfC
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totalCount){ !8]W"@qb
setPageSize(PAGESIZE);
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setTotalCount(totalCount); JpDc3^B*
setItems(items); 6vz9r)L
setStartIndex(0); @*W,Jm3Y
} : g/H N9
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public PaginationSupport(List items, int j3F[C:-zY
]*-9zo0
totalCount, int startIndex){ -\yaP8V
setPageSize(PAGESIZE); [Dp 6q~RM
setTotalCount(totalCount); eHG**@"X
setItems(items); NS"hdyA
setStartIndex(startIndex); VA_\Z
} C(C4R+U
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public PaginationSupport(List items, int Dq+rEt
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totalCount, int pageSize, int startIndex){ C\UD0r'p?
setPageSize(pageSize); BuI&kU,WY
setTotalCount(totalCount); &O(z|-&| x
setItems(items); 72} MspzUt
setStartIndex(startIndex); FLY#
} I'G$: GX
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publicList getItems(){ 2#5SI
return items; }NDw3{zn
} vWI9ocl`W
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publicvoid setItems(List items){ &| el8;D
this.items = items; H Kx2QFB
} R<)7,i`F
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publicint getPageSize(){ {$ 4fRxj
return pageSize; F?e_$\M
} <LQwH23@
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publicvoid setPageSize(int pageSize){ -uN5DJSW
this.pageSize = pageSize; LX4S}QXw
} _OP75kv
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publicint getTotalCount(){ %v:9_nwO)
return totalCount; |"DQ^)3Pi
} Q u2W
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publicvoid setTotalCount(int totalCount){ =dUeQ?>t=
if(totalCount > 0){ Ix !O&_6s
this.totalCount = totalCount; fLAOA9
int count = totalCount / D_`MeqF}C
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pageSize; Z1u{.^~ ^z
if(totalCount % pageSize > 0) G $:T!
count++; 4dv+RRpGOv
indexes = newint[count]; >Rs:Fw|jro
for(int i = 0; i < count; i++){ zS 18Kl
indexes = pageSize * Hb=4k)-/]
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i; &V$_u#<
} QM`A74j0]\
}else{ Uaog_@2n,
this.totalCount = 0; V9NE kS
} $fV47;U'*
} 7qq}wR]]
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publicint[] getIndexes(){ BZ<Q.:)
return indexes; su>GeJiPW
} o X )r4H?
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publicvoid setIndexes(int[] indexes){ J7/"8S_#N
this.indexes = indexes; 1om :SHw
} +'Pf|S
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publicint getStartIndex(){ #GT/Q3{C
return startIndex; u) y6 $
} J,%v`A ~N
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publicvoid setStartIndex(int startIndex){ b;`gxXeL
if(totalCount <= 0) lhva|
this.startIndex = 0; bEyZRG
elseif(startIndex >= totalCount) 03L+[F&"?
this.startIndex = indexes LJ`*&J
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[indexes.length - 1]; (e6JI]tz{
elseif(startIndex < 0) TZT i:\nS
this.startIndex = 0; i[sHPEml(5
else{ d4t%/ Uh
this.startIndex = indexes }&Ngh4/
}p$>V,u
[startIndex / pageSize]; qasbK:}
} !#`
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} py VTA1
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publicint getNextIndex(){ D/^yAfI
int nextIndex = getStartIndex() + aFGEHZJQ
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pageSize; vx62u29m
if(nextIndex >= totalCount) d5T M_C
return getStartIndex(); b^_#f:_j
else UUJbF$@;
return nextIndex; Z5/^pyc
} F=!p7msRB
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publicint getPreviousIndex(){ AE? 0UVI
int previousIndex = getStartIndex() - F9p'|-
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pageSize; GcaLP*%>B
if(previousIndex < 0) #N9^C@
return0; 88x_}M^Fnl
else _b|mSo,{Y
return previousIndex; Evu`e=LaG
} Cl#PYB{1Y
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} E7X6Shng
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抽象业务类 ?_)b[-N!
java代码: j}O~6A>|
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/** m1H|C 3u8
* Created on 2005-7-12 .UX`@Q:Gp
*/ V&)Jvx}^
package com.javaeye.common.business; v6=pV4k9
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import java.io.Serializable; 4FrP%|%E~
import java.util.List; 8 *o*?1.
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import org.hibernate.Criteria; &iKy
import org.hibernate.HibernateException; ~+DPq|-O
import org.hibernate.Session; HXV4E\JA
import org.hibernate.criterion.DetachedCriteria; EMy>X
import org.hibernate.criterion.Projections; @'n075)h
import @A32|p}
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org.springframework.orm.hibernate3.HibernateCallback; @cYb37)q=
import TLu+5f
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org.springframework.orm.hibernate3.support.HibernateDaoS xs#g
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upport; x -;tV=E}
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import com.javaeye.common.util.PaginationSupport; %M)LC>c
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public abstract class AbstractManager extends H!SFSgAu
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HibernateDaoSupport { ,f*Q3 S/I
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privateboolean cacheQueries = false; YMSZcI
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privateString queryCacheRegion; w?#s)z4}g
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publicvoid setCacheQueries(boolean I<+EXH%1,
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cacheQueries){ 4og/y0n,l"
this.cacheQueries = cacheQueries; [?>\]
} -v %n@8p
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publicvoid setQueryCacheRegion(String 0RZ[]:(
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queryCacheRegion){ /SW*y@R2l
this.queryCacheRegion = ;cEoc(<?
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queryCacheRegion; ,ZV>"'I:
} m?O~(6k@C
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publicvoid save(finalObject entity){ !S~0T!afF
getHibernateTemplate().save(entity); XCyU)[wY
} d/Sw.=vq
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publicvoid persist(finalObject entity){ r03%+:
getHibernateTemplate().save(entity); FG!2h&k
} nEt{ltsS0
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publicvoid update(finalObject entity){ ^UCH+Cyl
getHibernateTemplate().update(entity); [KL-T16
} E1j3c
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publicvoid delete(finalObject entity){ Kn=0AdM
getHibernateTemplate().delete(entity); w,i?e\5
} =&i#NSK
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publicObject load(finalClass entity, KCIya[$*
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finalSerializable id){ \RqH"HqD
return getHibernateTemplate().load W3zYE3DZf
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(entity, id); eDsB.^|l
} ZkJLq[:cM
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publicObject get(finalClass entity, L}
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finalSerializable id){ ~t<G gNI
return getHibernateTemplate().get +
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(entity, id); <Umr2Vw-
} K491QXG
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publicList findAll(finalClass entity){ 5sANF9o!
return getHibernateTemplate().find("from %:s+5*SKe
*_Vv(H&
" + entity.getName()); RFLfvD<
} IH&0>a
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publicList findByNamedQuery(finalString _NB*+HVo
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namedQuery){ -{}h6r
return getHibernateTemplate y/E:6w
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().findByNamedQuery(namedQuery); i)$P1h
} ?7]G)8G6
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publicList findByNamedQuery(finalString query, 5%N[hd1Ql
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finalObject parameter){ )m#Y^
return getHibernateTemplate ,k_"T.w
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().findByNamedQuery(query, parameter); H$ %F0'0
} &09&;KJ
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publicList findByNamedQuery(finalString query, h
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finalObject[] parameters){ ohbU~R3{U
return getHibernateTemplate EDz;6Z*4N
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().findByNamedQuery(query, parameters); Lk!m1J5
} \FUMfo^
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publicList find(finalString query){ }L(ZLt8Q
return getHibernateTemplate().find Y0Tad?iC
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(query); n"`V|
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} gD51N()s,
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publicList find(finalString query, finalObject P z~jW):E
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parameter){ ZH|q#<{l
return getHibernateTemplate().find 2{.g7bO
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(query, parameter); I-}ms
} [-VK!9pQ
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public PaginationSupport findPageByCriteria "P0!cY8r
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(final DetachedCriteria detachedCriteria){ 0zA;%oP
return findPageByCriteria {:3\Ms#
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); \i/HHP[%
} 2Mk;r*FT
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public PaginationSupport findPageByCriteria `kJ)E;v;3
P
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(final DetachedCriteria detachedCriteria, finalint nShXY6bA
@I-,5F|r
startIndex){ "b~C/-W I
return findPageByCriteria Pc*lHoVL
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(detachedCriteria, PaginationSupport.PAGESIZE, WKiP0~
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startIndex); o5p{ O>D[z
} 1&! i:F#
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public PaginationSupport findPageByCriteria U+qyS|i
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(final DetachedCriteria detachedCriteria, finalint r&m49N,d
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pageSize, s2"`j-iQ
finalint startIndex){ g3c<c S^l
return(PaginationSupport) ?5J#
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getHibernateTemplate().execute(new HibernateCallback(){ OA*O =
publicObject doInHibernate 9c[X[Qc
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(Session session)throws HibernateException { )I[f(f%W7
Criteria criteria = #<< el;n
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detachedCriteria.getExecutableCriteria(session); lwq:0Rj@Q
int totalCount = ns%gb!FBJX
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((Integer) criteria.setProjection(Projections.rowCount b"A,q
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()).uniqueResult()).intValue(); o3dqsQE%
criteria.setProjection )][U6 e
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(null); _i {Y0d+
List items = zawu(3?~)5
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:
criteria.setFirstResult(startIndex).setMaxResults !nSa4U,$w<
w[
v{)
(pageSize).list(); 9^W7i]-Z
PaginationSupport ps = S[exnZ*Y
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new PaginationSupport(items, totalCount, pageSize, *sOb I(&
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startIndex); ekvs3a^
return ps; B^/MwD>%
} #zTy7ZS,0
}, true); a*y9@RC}
} A:< %>
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public List findAllByCriteria(final _K9`o^g%PJ
^AH[]sE_
DetachedCriteria detachedCriteria){ gLX<>|)*
return(List) getHibernateTemplate 7S}0Kuk)
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().execute(new HibernateCallback(){ 4%J0e'iN
publicObject doInHibernate ot<d
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(Session session)throws HibernateException { AOZ C D{
Criteria criteria = DLrV{8%W
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detachedCriteria.getExecutableCriteria(session); MvpJ0Y (
return criteria.list(); RG{T\9]n
} 9s^$tgH
}, true); QMBT8x/+_'
} bFX{|&tHU
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public int getCountByCriteria(final qR'FbI
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DetachedCriteria detachedCriteria){ Zu.hcDw1
Integer count = (Integer) ,!l _
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getHibernateTemplate().execute(new HibernateCallback(){ T&_&l;syA
publicObject doInHibernate #gQn3.PX+y
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(Session session)throws HibernateException { RqTO3Kf
Criteria criteria = 8TFQ%jv
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detachedCriteria.getExecutableCriteria(session); N1ipK9a
return $(9QnH1KY
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criteria.setProjection(Projections.rowCount Vx $;wU Y
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()).uniqueResult(); R'v~:wNTNs
} J#..xJ?XRD
}, true); l1 Kv`v\
return count.intValue(); =IC.FT}
} F"]P|
} :/T\E\Qr
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用户在web层构造查询条件detachedCriteria,和可选的 13s/m&
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 bp?5GU&Uy
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PaginationSupport的实例ps。 EH|+S
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ps.getItems()得到已分页好的结果集 3s%?)z
ps.getIndexes()得到分页索引的数组 N[/<xW~x?4
ps.getTotalCount()得到总结果数 pt<zyH3Z
ps.getStartIndex()当前分页索引 &zJI~R
ps.getNextIndex()下一页索引 =K`.$R
ps.getPreviousIndex()上一页索引 \1<'XVS
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 MLWHO$C~T
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 [e+Y7M7
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一下代码重构了。 gI^&z
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我把原本我的做法也提供出来供大家讨论吧: !2|Lb'O
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首先,为了实现分页查询,我封装了一个Page类: |owr?tC
java代码: O@Aazc5K
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/*Created on 2005-4-14*/ t$!zgUJ
package org.flyware.util.page;
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/** >-MnB
* @author Joa m# {'9 |
* i6if\B
*/ 1 (<n^\J(
publicclass Page { s/"bH3Ob9v
*O_fw 0jV
/** imply if the page has previous page */ JH.XZM&
privateboolean hasPrePage; ['mpxtG
uFWA] ":is
/** imply if the page has next page */ b9j}QK
privateboolean hasNextPage; $Z G&d
hZ4 5i?%
/** the number of every page */ T~]~'+<Pi
privateint everyPage; gnp.!-
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/** the total page number */ {lds?AuK
privateint totalPage; ,%9XG077
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/** the number of current page */ .\XRkr'-
privateint currentPage; y<Koc>8
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/** the begin index of the records by the current V(&L
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query */ 1TZ[i
privateint beginIndex; /!Rva"
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/** The default constructor */ \tgY2:
public Page(){ Wg}KQ6
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} s-CAo~,
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/** construct the page by everyPage [(n5-#1S
* @param everyPage vU>^
* */ 0fqcPi
public Page(int everyPage){ q'jOI_b
this.everyPage = everyPage; e i=
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} j3sz"(
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/** The whole constructor */ u#ya
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public Page(boolean hasPrePage, boolean hasNextPage, gT8(LDJ
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int everyPage, int totalPage, s\d3u`G
int currentPage, int beginIndex){ <f7 O3 >
this.hasPrePage = hasPrePage; .BPd06y
this.hasNextPage = hasNextPage; V6merT79
this.everyPage = everyPage; ci;2XLAM
this.totalPage = totalPage; mP^ B2"|q
this.currentPage = currentPage; #eJfwc1JY
this.beginIndex = beginIndex; ?xaUWD
} I"x'
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/** C1-U2@
* @return :-x?g2MY
* Returns the beginIndex. 5X0ex.
*/ ?62zv[#
publicint getBeginIndex(){ hrniZ^
return beginIndex; [+WsVwyf?
}
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/** EP38Ho=[
* @param beginIndex @*hv|zjs
* The beginIndex to set. n~lB}
*/ _h1bVd-
publicvoid setBeginIndex(int beginIndex){ Sj ovL@X
this.beginIndex = beginIndex; @JSWqi>
} :3M,]W]
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/** %/2
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* @return `*U@d%a
* Returns the currentPage. S\Z*7j3;M
*/ Jz''UJY/O
publicint getCurrentPage(){ qBk[Afjgz
return currentPage; Uv59 XF$
} z
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[
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/** }e7/F[c.U
* @param currentPage yl>^QMmo
* The currentPage to set. lz=DGm
*/ VY/r2o#
publicvoid setCurrentPage(int currentPage){ .yF-<Y
this.currentPage = currentPage; 6ud?US(
} jpi,BVTI-X
bN?*p($/
/** ,GWa3.&.d
* @return 0^{Tq0Ri[
* Returns the everyPage. QY+{ OCB
*/ 7_Vd%<:
publicint getEveryPage(){ g,E)F90
return everyPage; jYU0zGpj
} e|A=sCN-
a3A-N] ;f
/** -)J*(7F(6^
* @param everyPage Q-,
4
* The everyPage to set. o< b
*/ nILUo2e~
publicvoid setEveryPage(int everyPage){ <> =(BAw
this.everyPage = everyPage; h9Sf
} +4t
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/** L^^f.w#m
* @return =2Ju)!%wr
* Returns the hasNextPage. bIt{kzuQC
*/ e>Q:j_?.e
publicboolean getHasNextPage(){ F\+9u$=
return hasNextPage; =[4C[s
} 2aivc,m{r
d}E6d||A
/** '(ETXQ@
* @param hasNextPage un6W|{4]
* The hasNextPage to set. !G;BYr>X
*/ U&kdR+dB
publicvoid setHasNextPage(boolean hasNextPage){ sC.cMZ e
this.hasNextPage = hasNextPage; @6 jKjI
} w#(E+s~}
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/** \XY2s&"
* @return PClwGO8'&
* Returns the hasPrePage. Ejf>QIB
*/ I~
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publicboolean getHasPrePage(){ 1\f8-:C
return hasPrePage; .:['&; k
} ~}YgZ/U7T
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/** qB3&F pgW
* @param hasPrePage ({rescQB
* The hasPrePage to set. arPqVMVr
*/ z<"\I60Fe
publicvoid setHasPrePage(boolean hasPrePage){ q[Y*.%~
this.hasPrePage = hasPrePage; (B+zh
} T7G{)wm
LrfyH"#!:
/** %gEfG#S
* @return Returns the totalPage. +DT)7koA
* xI=[=;L
*/ /i~n**HeF?
publicint getTotalPage(){ +fF4]WFP
return totalPage; h8SK8sK<
} l&Fx<
W
~i@Z4tj7
/** (P:.@P~
* @param totalPage 5#? HL
* The totalPage to set. 9T;l*
*/ 8-vNXvl
publicvoid setTotalPage(int totalPage){ Vzrp9&loY
this.totalPage = totalPage; 1lUY27MF
} u|8V7*)3
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} -/qu."9(B
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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
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个PageUtil,负责对Page对象进行构造: QXT*O
java代码: oY%NDTVN
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/*Created on 2005-4-14*/ 8-R; &
package org.flyware.util.page; t5za$kW'&
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import org.apache.commons.logging.Log; ;,]Wtmu)7
import org.apache.commons.logging.LogFactory; j.rJfbE|X
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/** of:xj$dQ_
* @author Joa 0~XZ
*
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*/ M>g\Y
publicclass PageUtil { nz]+G2h
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privatestaticfinal Log logger = LogFactory.getLog ]q@6&]9
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(PageUtil.class); j kIgEF2d*
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/** ;/Dp
* Use the origin page to create a new page Cc,,e`
* @param page rt\4We,7
* @param totalRecords h=~TgTv
* @return 7fJWb)z!k
*/ 1e#}+i!a
publicstatic Page createPage(Page page, int DrB PC@^
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totalRecords){ cA4xx^~
return createPage(page.getEveryPage(), 7].FdjT.
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page.getCurrentPage(), totalRecords); !8O*)=RA
} +H~})PeQ
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/** poYO
* the basic page utils not including exception <OEu 4,~:
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9
handler !8U\GR `
* @param everyPage .pOTIRbA
* @param currentPage ^i^/d#
* @param totalRecords y++[:M
* @return page y
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*/ 58Fan*fO
publicstatic Page createPage(int everyPage, int *.J)7~(P
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currentPage, int totalRecords){ 5Vzi{y/bL
everyPage = getEveryPage(everyPage); =5jX#Dc5.+
currentPage = getCurrentPage(currentPage); qffXm`k
int beginIndex = getBeginIndex(everyPage, 8I'c83w
<OcD [5
currentPage); O&?i8XsB
int totalPage = getTotalPage(everyPage, Q!:J.J
iC`K$LY4W
totalRecords); RAQi&?Ko
boolean hasNextPage = hasNextPage(currentPage, [s4lSGh
{`vF4@
totalPage); >c>f6
boolean hasPrePage = hasPrePage(currentPage); hp]T ^
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returnnew Page(hasPrePage, hasNextPage, pN"d~Z8
everyPage, totalPage, DUxj^,mf,
currentPage, ]N^a/&}*
9BPucXK
beginIndex); #AzZ4<;7
} 7W6tz\Y
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privatestaticint getEveryPage(int everyPage){ '@h5j6:2
return everyPage == 0 ? 10 : everyPage; < 6[XE
} 9GuG"^08
vl<W`)'
privatestaticint getCurrentPage(int currentPage){ 3eqnc),Z
return currentPage == 0 ? 1 : currentPage; z )2h\S
} w^?uBeqR
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privatestaticint getBeginIndex(int everyPage, int C&b^TLe
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currentPage){ 18 pi3i[
return(currentPage - 1) * everyPage; e.%`
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} :[oFe/1K!4
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privatestaticint getTotalPage(int everyPage, int NWuS/Ur`9
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totalRecords){ ixZ w;+h
int totalPage = 0; y,i:BQJ<
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if(totalRecords % everyPage == 0) Q<.847 )
totalPage = totalRecords / everyPage; #wL}4VN
else j'#M'W3@
totalPage = totalRecords / everyPage + 1 ; /(Se:jH$>
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return totalPage; vq|o}6Et
} 7{
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privatestaticboolean hasPrePage(int currentPage){ 8jW"8~Y#0
return currentPage == 1 ? false : true; M}E0Msq_o
} Q%61_l
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privatestaticboolean hasNextPage(int currentPage, s*.CJ
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int totalPage){ 7yGc@kJ?
return currentPage == totalPage || totalPage == qi7(RL_N
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0 ? false : true; 4vi P lO
} 5(0f"zY
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} \^O#)&5 V
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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。 #flOaRl.
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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 =~M%zdIXv
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做法如下: :r%Hsur(
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 <smi<syx
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的信息,和一个结果集List: `NqX{26GV+
java代码: dHp(U
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d7 )&Z:
/*Created on 2005-6-13*/ tW4|\-E"s4
package com.adt.bo; PMER~}^
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import java.util.List; T=6fZ;7
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import org.flyware.util.page.Page; w E^6DNh
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/** y{CyjYpz^
* @author Joa 8YNii-pl
*/ HP T{83
publicclass Result { DA'A-C2
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private Page page; > <cK
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private List content; x8H%88!j*
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/** .I%p0ds1r
* The default constructor -:92<G\D
*/ '\yp}r'u
public Result(){ fAMJFHW
super(); d5?"GFy
} HF@K$RPK
hZ_0lX}
/** o(iv=(o
* The constructor using fields XEd|<+P1
* %si5cc?
* @param page +[l52p@a
* @param content *Jd,8B/hC
*/ <