Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 &4BN9`|:
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 tK]r>?Y\
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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 =_v_#;h&
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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 \9D
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分页支持类: ,gRsbC
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java代码: 2Uk$9s
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package com.javaeye.common.util; lfWxdi
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import java.util.List; )7J@A%u
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publicclass PaginationSupport { rY($+O@a<
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publicfinalstaticint PAGESIZE = 30; {mueP6Gz@J
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privateint pageSize = PAGESIZE; }HXNhv-K
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privateList items; =">O;L.xj
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privateint totalCount; nc&V59*
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privateint[] indexes = newint[0]; X"'}1o
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privateint startIndex = 0; WKmGw^
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public PaginationSupport(List items, int i' N
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totalCount){ # {!Qf\1M
setPageSize(PAGESIZE); TX8,+s+
setTotalCount(totalCount); w,JB`jS)/
setItems(items); O2A Z|[*I
setStartIndex(0); 0} HKmEM
} %'t~+_
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public PaginationSupport(List items, int *gZ4Ub|O
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totalCount, int startIndex){ 3Jk;+<
setPageSize(PAGESIZE); U2+CL)al^
setTotalCount(totalCount); QJ pUk%Wj
setItems(items); .$S`J2Y
setStartIndex(startIndex); K+Ehj(eF
} d<: VoQM6M
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public PaginationSupport(List items, int 8ae]tX5$
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totalCount, int pageSize, int startIndex){ }%_x T
setPageSize(pageSize); O^oFH
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setTotalCount(totalCount); m.S@ e8kS
setItems(items); &*L:4By)]
setStartIndex(startIndex); #p*OLQ3~
} hIPDJ1a
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publicList getItems(){ ' J]V"Z)
return items; >l'QX(
} R}Z"Yxx
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publicvoid setItems(List items){ fl+
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this.items = items; pD.7ib^
} ~eqX<0hf@
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publicint getPageSize(){ hRGK W
return pageSize; jw#'f%*
} ToDN^qE+
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publicvoid setPageSize(int pageSize){ * F~"4g
this.pageSize = pageSize; nM)]
} gwR ^Z{
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publicint getTotalCount(){ K'n^,
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return totalCount; WB$Z<m:
} jcFh2
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publicvoid setTotalCount(int totalCount){ ZXHG2@E)
if(totalCount > 0){ j:$2,?|5
this.totalCount = totalCount; fd*=`+P
int count = totalCount / -Qqb/y
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pageSize; Y( D d7`c
if(totalCount % pageSize > 0) T"8>6a@}E
count++; XQ,IEj|
indexes = newint[count]; =F8uuYX%m
for(int i = 0; i < count; i++){ 7f[nNng
indexes = pageSize * #`v`e"
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i; ~F>oNbJIv
} kzgHp,;R{
}else{ )v8;\1`s:
this.totalCount = 0; pg*'2AT
} #j iQa"
} tkV:kh< L~
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publicint[] getIndexes(){ ^/mQo`[G
return indexes; LQNu]2
} m7^a4
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publicvoid setIndexes(int[] indexes){ #qm<4]91
this.indexes = indexes; ks
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} u\&oiwSIP
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publicint getStartIndex(){ G:A~nv9
return startIndex; q.~.1
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} 26.iFt/:
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publicvoid setStartIndex(int startIndex){ -:cS}I
if(totalCount <= 0) =5I1[p;
this.startIndex = 0; 6DR@$fpt
elseif(startIndex >= totalCount) _(J- MCY\
this.startIndex = indexes +5?sYp\
X1#D}
[indexes.length - 1]; pRUN[[L
elseif(startIndex < 0) w&`gx6?-na
this.startIndex = 0; q;tsA"l
else{ (fm\kV
this.startIndex = indexes xgsD<3
bq<QUw=]q&
[startIndex / pageSize]; "p2 $R*ie
} v#YO3nD
} +*!oZKm.
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publicint getNextIndex(){ k[y{&f,
int nextIndex = getStartIndex() + -H'_%~OV(
c@5fiRPv!
pageSize; 7 fqK{^L
if(nextIndex >= totalCount) _6^ vxlF
return getStartIndex(); 7b:oz3 ?PI
else |C7GI[P
return nextIndex; X\X
} \qV5mD]"M
>xJt&jW-
publicint getPreviousIndex(){ {B?%r[nW
int previousIndex = getStartIndex() - 2frJSV ?
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pageSize; </:f-J%U/
if(previousIndex < 0) RyIr_:&-~
return0; h_*=_ 2|}
else V |#B=W
return previousIndex; @ g~kp
} b(;"p-^
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} REQ2pfk0
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抽象业务类 XrFyN(p
java代码: XuoI19V[
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/** 8[(c'rl|)|
* Created on 2005-7-12 s2b!Nib
*/ ?n\~&n'C
package com.javaeye.common.business; @<W"$_r-
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import java.io.Serializable; \
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import java.util.List; `:i|y
'[`.&-;
import org.hibernate.Criteria; +CX2W('
import org.hibernate.HibernateException; ItC*[
import org.hibernate.Session; 57v[b-SK
import org.hibernate.criterion.DetachedCriteria; IOvYvFUUJ
import org.hibernate.criterion.Projections; `$G7Ia_ $]
import XRJ<1w:
k[A=:H1"
org.springframework.orm.hibernate3.HibernateCallback; )1~4Tl,S
import kH-1l>":
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org.springframework.orm.hibernate3.support.HibernateDaoS ]$y"|xqR
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upport; 3`SLMPI
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import com.javaeye.common.util.PaginationSupport; o
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pt
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public abstract class AbstractManager extends <LzN/I aJ
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HibernateDaoSupport { Q(oWaG
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privateboolean cacheQueries = false; RTH dL
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privateString queryCacheRegion; $M$oNOT}Y
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publicvoid setCacheQueries(boolean 9 n|H%AC
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cacheQueries){ EG7ki0
this.cacheQueries = cacheQueries; s/`4]B;2U
} k-b_
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publicvoid setQueryCacheRegion(String }1N)3~
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queryCacheRegion){ o Ep\po1
this.queryCacheRegion = =QRLKo#_
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queryCacheRegion; ;vQ7[Pv.j
} )
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publicvoid save(finalObject entity){ O0WzDD
getHibernateTemplate().save(entity); wvx
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} &>i+2c~
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publicvoid persist(finalObject entity){ 8
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getHibernateTemplate().save(entity); 7I(Sa?D:
} ,5t.0XqS
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publicvoid update(finalObject entity){ -t:yy:4
getHibernateTemplate().update(entity); JAmv 7GL'6
} 76zi)f1f
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publicvoid delete(finalObject entity){ %mtW-drv>
getHibernateTemplate().delete(entity); )nQpO"+M
} :g+R}TR[i
p,]Hs{R
publicObject load(finalClass entity, YUM%3
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finalSerializable id){ )-2OraUm<
return getHibernateTemplate().load xI}]q%V
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(entity, id); r\` R$
} -[0)n{AVvU
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publicObject get(finalClass entity, 9 oc.`-e\?
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finalSerializable id){ Ct$e`H!;
return getHibernateTemplate().get QOy+T6en
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(entity, id); niqi DT/
} QmT]~4PqS
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publicList findAll(finalClass entity){ :E@"4O?<Y)
return getHibernateTemplate().find("from ?G0=\U<
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" + entity.getName()); A;Xn#t ,(K
} Ur?a%]
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publicList findByNamedQuery(finalString Y;xVB"
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namedQuery){ %CD}A%~
return getHibernateTemplate vxk1RL*Xu
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().findByNamedQuery(namedQuery); wEQV"I
} Co[ rhs
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publicList findByNamedQuery(finalString query,
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finalObject parameter){ VISNmz2P
return getHibernateTemplate }`h)+Im=
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().findByNamedQuery(query, parameter); #f\U3p
} vZhN%
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publicList findByNamedQuery(finalString query, o_bj@X
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finalObject[] parameters){ qyp"q{k0
return getHibernateTemplate w# ,:L)
>9uDY+70I3
().findByNamedQuery(query, parameters); 0rsdDME[
} FL/@e$AK
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publicList find(finalString query){ T&w3IKb|}
return getHibernateTemplate().find 4F)z-<-b
BqCBH!^x
(query); j:O=9
} _dmgNbs
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publicList find(finalString query, finalObject UccnQZ7/I
q 1Rk'k4+
parameter){ C8-4 m68"
return getHibernateTemplate().find kNd[M =%
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(query, parameter); m9wV#Ldu
} mI@E>VCV[
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public PaginationSupport findPageByCriteria 0p*(<8D}
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(final DetachedCriteria detachedCriteria){ Gv?'R0s
return findPageByCriteria "
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); #'v7mEwt
} 2|qE|3&{'
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public PaginationSupport findPageByCriteria z"Gk K T
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(final DetachedCriteria detachedCriteria, finalint M$FQoRwH
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startIndex){ "m3u}!`3
return findPageByCriteria Y"K7$+5#\
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(detachedCriteria, PaginationSupport.PAGESIZE, [6FCbzS_W
u;F++$=
startIndex); n^UrHHOL
} iKv{)5
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public PaginationSupport findPageByCriteria 1WfN_JKB5
;B:'8$j$
(final DetachedCriteria detachedCriteria, finalint kC!7<%(
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pageSize, gX{V>T(<
finalint startIndex){ di
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return(PaginationSupport) z%hB=V!~91
;v[F@O~*)
getHibernateTemplate().execute(new HibernateCallback(){ TMhUo#`I|
publicObject doInHibernate Io|NL6[
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(Session session)throws HibernateException { lw\OsB$
Criteria criteria = ;E,%\<
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detachedCriteria.getExecutableCriteria(session); "e&S*8QhM
int totalCount = WW:@% cQ@
#]_S{sO
((Integer) criteria.setProjection(Projections.rowCount
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";J1$a
()).uniqueResult()).intValue(); 7;dV]N
criteria.setProjection {[m %1O1
>dUnk)7
(null); |z<E%`u%
List items = _W@q %L>
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criteria.setFirstResult(startIndex).setMaxResults LrX7WI
%A,4vLe~6
(pageSize).list(); 9mEC|(m*WK
PaginationSupport ps = |p4F^!9
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new PaginationSupport(items, totalCount, pageSize, KA0Ui,q3
)|x)KY
startIndex); &y;('w
return ps; '{5|[
} Be68 Fu0
}, true); RnE=T/VZJ
} xx)egy_
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public List findAllByCriteria(final g7EJyA
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DetachedCriteria detachedCriteria){ l`:M/z6"
return(List) getHibernateTemplate "]f0wLzh
S#/[>Cb
().execute(new HibernateCallback(){ ^cz#PNB
publicObject doInHibernate 'gxSHqeI2
5%mc|
(Session session)throws HibernateException { <Qe30_<K
Criteria criteria = u.ffZ]\7l
X|{TwmHd
detachedCriteria.getExecutableCriteria(session); uCB7(<
return criteria.list(); ]E .+)>
} 8`EzvEm
}, true); $VvL
}
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public int getCountByCriteria(final ryy".'v
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DetachedCriteria detachedCriteria){ >)YaWcI
Integer count = (Integer) @/@#,+
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getHibernateTemplate().execute(new HibernateCallback(){ xL3-(K6e
publicObject doInHibernate c:.k2u
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(Session session)throws HibernateException { P3jDx{F
Criteria criteria = 4yW9}=N!
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detachedCriteria.getExecutableCriteria(session); `PXSQf
return f}PT3
ng(STvSh:
criteria.setProjection(Projections.rowCount .S>:-j'u
1@JAY!yoo_
()).uniqueResult(); M.O3QKU4
} IGeXj%e
}, true); f7c%Z:C#Y
return count.intValue(); cY
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} ]mYT!(}
} 9YS &RBJu
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用户在web层构造查询条件detachedCriteria,和可选的 \R#]}g0!
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 1K.i>]}>
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PaginationSupport的实例ps。 *~~ >?
u )cc
ps.getItems()得到已分页好的结果集 g)c<\%
ps.getIndexes()得到分页索引的数组 J8>y2rAi
ps.getTotalCount()得到总结果数 [1K\
_
ps.getStartIndex()当前分页索引 _]E H~;
ps.getNextIndex()下一页索引 M@ILB-H
ps.getPreviousIndex()上一页索引 } QVREj
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 +L
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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 gM~dPM|
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一下代码重构了。 eT* )r~
mcvd/
我把原本我的做法也提供出来供大家讨论吧: 7~n<%q/6
{WfZE&B
首先,为了实现分页查询,我封装了一个Page类: q^NI
java代码: SC/|o
e=S51q_0
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/*Created on 2005-4-14*/ rvrv[^a(
package org.flyware.util.page; |zhVl
;LSdY}*%0
/** R+
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* @author Joa &o@IMbJ8
* :%-xiv
*/ *\ZK(/V
publicclass Page { xV@/z5Tq
R3=PV{`M
/** imply if the page has previous page */ S?TyC";!
privateboolean hasPrePage; (|H1zO
Qz6Ry\u
/** imply if the page has next page */ Ni"n_Yun
privateboolean hasNextPage; Dg(882#_
=w&JDj
/** the number of every page */ J;"66ue(d
privateint everyPage; aF2vw{wT}
T v2d?y
/** the total page number */ Z<+Ipj&
privateint totalPage; fy&vo~4i;
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/** the number of current page */ LA?h +)
privateint currentPage; sswYwU
Bs7/<$9K/
/** the begin index of the records by the current mT enzIp
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query */ 0G@sj7)]
privateint beginIndex; X633.]+
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/** The default constructor */ Ps=OL\i
public Page(){ B+W 4r9#
cVCylRU"
} DPIIE2X
i`#5dIb
/** construct the page by everyPage ^0"W/
* @param everyPage M;s r1C
* */ 6XU1w
public Page(int everyPage){ 8JYF0r7
this.everyPage = everyPage; n
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} %C}TdG(C
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/** The whole constructor */ VsLlPw{
public Page(boolean hasPrePage, boolean hasNextPage, aNn\URR
8)n799<.
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int everyPage, int totalPage, %-u Ra\
int currentPage, int beginIndex){ 9cV;W \ Tw
this.hasPrePage = hasPrePage; cO}`PD$i
this.hasNextPage = hasNextPage; G+Gd;`4
this.everyPage = everyPage; X'BFR]cm
this.totalPage = totalPage; ibe#Y
this.currentPage = currentPage; @&H Tt
this.beginIndex = beginIndex; liu%K9-r
} !=sM `(=~
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/** EtVRnI@
* @return M3>c?,O)J
* Returns the beginIndex. ]r6S|;:
*/ R`%C]uG
publicint getBeginIndex(){ )L^GGy8w
return beginIndex; |#uA(V
} @JFfyQ {-
aE]/w1a
/** kTJz .
* @param beginIndex GJ1ap^k
* The beginIndex to set. l]:nncpns
*/ 2|2'?
publicvoid setBeginIndex(int beginIndex){ 0xv@l^B
this.beginIndex = beginIndex; !aylrJJ
} ?;{d
%qN_<W&Ze
/** % Q| >t~
* @return o{C7V*
* Returns the currentPage. oaxCcB=\
*/ k{M4.a[(
publicint getCurrentPage(){ G.#`DaP
return currentPage; x+1Cs$E;
} "DWw]\xO](
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/** W+F{!dW
* @param currentPage kH&KE5
* The currentPage to set. 8v eG^o
*/ 7t8[M(
publicvoid setCurrentPage(int currentPage){ AHg:`Wjv-
this.currentPage = currentPage; '!$g<= @
} d46PAA{'
,\t:R1.
/** 0Fd<@wQ0
* @return *RPdU.
* Returns the everyPage. -)='htiU
*/ Io8h 8N-
publicint getEveryPage(){ d#Hl3]wT
return everyPage; kX0hRX
} =1/d>kke
6.uyY@Yx
/** ?zFeP6C
* @param everyPage "t[9EbFL
* The everyPage to set. @jXdQY%{
*/ jY: )W*TXt
publicvoid setEveryPage(int everyPage){ uL.)+E
this.everyPage = everyPage; ]Tv0+ Ao
} S!\4,6
$ NNd4d*
/** -> $]`h"
* @return }(*eR F'
* Returns the hasNextPage. `,-w+3?Al
*/ % 3"xn!'vf
publicboolean getHasNextPage(){ kPuY[~i%
return hasNextPage; pQ:7%+Om
} y;'yob
i .O670D
/** '>8IOC
* @param hasNextPage _zuaImJ0o
* The hasNextPage to set. `a$c6^a
*/ HUP~
publicvoid setHasNextPage(boolean hasNextPage){ p,(gv])ie
this.hasNextPage = hasNextPage; Nft~UggK
} G=1&:nW'
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/** ^`BiA'gPPC
* @return -'q#u C
* Returns the hasPrePage. 8ClOd<I
*/ z' oK
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publicboolean getHasPrePage(){ O~wZU Zf
return hasPrePage; pfs'2AFj
} E.ugr])
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/** //x^[fkNq)
* @param hasPrePage f1Az|h
* The hasPrePage to set. m'j]T/WF
*/ fu=GgD*
publicvoid setHasPrePage(boolean hasPrePage){ <%_7%
this.hasPrePage = hasPrePage; D@O#P^?
} (pDu
<./r%3$;7
/** ||xiKg
* @return Returns the totalPage. 9A7LDHst7
* _m?TEqB
*/ eNQQ`ll@m
publicint getTotalPage(){ ~g#$'dS
return totalPage; >EacXPt-O
} /-{C,+cB
FV 0x/)<z
/** \/wbk`2
* @param totalPage sxP1.= W
* The totalPage to set. vO?\u`vY
*/ }|KNw*h$
publicvoid setTotalPage(int totalPage){ @zQ.d{
this.totalPage = totalPage; 6h?v/\
} )\`.Ru~,
.eNeqC
} :kQ%Mj>
[|5gw3y
>'/KOK"
o(gEyK
\#yKCA';
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 Xur{nk~?
gpvzOW/
个PageUtil,负责对Page对象进行构造: qk+RZ>T<o
java代码: ep ,"@,,
C>MEgGP
\dx$G?R
/*Created on 2005-4-14*/ jmE\+yz
package org.flyware.util.page; [iO*t,3@h
I:l/U-b7h
import org.apache.commons.logging.Log; C6PlO
import org.apache.commons.logging.LogFactory; 5s7C;+
'5usPD
/** ]Yw/}GKB
* @author Joa p;x3gc;0
* "sD[P3
*/ (#)-IdXXO<
publicclass PageUtil { ,E._A(Z
\>G :mMk/
privatestaticfinal Log logger = LogFactory.getLog 0#/N ZO
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(PageUtil.class); crDm2oA~t
J#/L}h;qH
/** ,UveH` n-
* Use the origin page to create a new page aAi"
* @param page U+4W9zhwo
* @param totalRecords M^6!{c=MIi
* @return C/JFb zVx
*/ ^e~m`R2fHh
publicstatic Page createPage(Page page, int b}-/~l-:
Fr|Ts>Kx
totalRecords){ =>0G
return createPage(page.getEveryPage(), W,D$=Bg
#}lq2!f6
page.getCurrentPage(), totalRecords); !vY5X2?tr,
} `Lr I^9Z
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/** O: J;zv\
* the basic page utils not including exception Cqra\
@p\te7(P%
handler N
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* @param everyPage Y+ Qm.
* @param currentPage 4k]DktY}.
* @param totalRecords 37U2Tb!y'
* @return page LP{@r ic
*/ .wPu
#*
publicstatic Page createPage(int everyPage, int k@Q>(`
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currentPage, int totalRecords){ &2Q0ii#Aa
everyPage = getEveryPage(everyPage); M&h`uO/[
currentPage = getCurrentPage(currentPage); DxvD 1u
int beginIndex = getBeginIndex(everyPage, <uf,@N5m
`at>X&Ce,
currentPage); ,UA-Pq3}
int totalPage = getTotalPage(everyPage, @&F\ M}
T!ik"YZ@i
totalRecords); a{y"vVQOF
boolean hasNextPage = hasNextPage(currentPage, gwQk
M4
7,!$lT#
totalPage); x 3C^ S~
boolean hasPrePage = hasPrePage(currentPage); 8jdEx&K
+wpQ$)\
returnnew Page(hasPrePage, hasNextPage, 8j^3_lD
everyPage, totalPage, mW 4{*
currentPage, Cu,#w3JR
2+'4 m#@)
beginIndex); >$/PfyY7@#
} 0,M1Q~u%.
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privatestaticint getEveryPage(int everyPage){ sI% =G3o=
return everyPage == 0 ? 10 : everyPage; ?>}&,:U}
} MVYf-'\^
s6HfN'
privatestaticint getCurrentPage(int currentPage){ a(|,KWHn
return currentPage == 0 ? 1 : currentPage; +}Q@{@5w
} XT<{J8
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privatestaticint getBeginIndex(int everyPage, int 0'nY
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currentPage){ /)LI1\o
return(currentPage - 1) * everyPage; dl;
} T0F!0O `
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privatestaticint getTotalPage(int everyPage, int #
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totalRecords){ F =Zc_
int totalPage = 0; s<`54o ,
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if(totalRecords % everyPage == 0) 'H|=]n0
totalPage = totalRecords / everyPage; U|YIu!^
else SGA!%=Lp
totalPage = totalRecords / everyPage + 1 ; ]$xN`O4W{
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return totalPage; D8r=Vf
} 7O^'?L<C'
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privatestaticboolean hasPrePage(int currentPage){ A3cW8OClz
return currentPage == 1 ? false : true; rZSX fgfr
} 9 ! 6\8
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privatestaticboolean hasNextPage(int currentPage, LI/;`Y=
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int totalPage){ ,f2tG+P
return currentPage == totalPage || totalPage == }ki}J >j|f
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0 ? false : true; U%)m
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} >Vl8ZQ8
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} DD(K@M
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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。 PRi3=3oF
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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 A;g{H|
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做法如下: 7x ?2((
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Bx&F* a;5
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的信息,和一个结果集List: <z+b88D
java代码: \'AS@L"Wj^
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/*Created on 2005-6-13*/ $k=5nJ
package com.adt.bo; SF#Rc>v
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import java.util.List; &GetRDr
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import org.flyware.util.page.Page; 3$hbb6N%6.
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/** SFdSA4D"
* @author Joa rDvz2p"R
*/ W<"{d
publicclass Result { hExw} c
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private Page page; 2*<'=*zaQ
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private List content; 3jG
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/** %C^%Oq_k
* The default constructor >*"6zR2 o
*/ @uaf&my,P
public Result(){ *gxo!F}
super(); pPX ~pPIj2
} =e>#oPH
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/** iH#b"h{w
* The constructor using fields A7SE>e>
* EE<^q?[3^
* @param page ^Nu0+S
* @param content \h&ui]V
*/ :1O1I2L0
public Result(Page page, List content){ AHA4{Zu[
this.page = page; M zbs#v0
this.content = content; &D[pX|!
} h)746T )
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/** ggR--`D[
* @return Returns the content. &