Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 NrK.DY4
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 L<62-+e`
o<8('j
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 e>] gCa
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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 (& UQ^
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。 (E{}iq@2
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分页支持类: J^V}%N".
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java代码: J_S8=`f%
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package com.javaeye.common.util; qC x|}5:
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import java.util.List; uSgR|b;R]
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publicclass PaginationSupport { >_J9D?3S
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publicfinalstaticint PAGESIZE = 30; |8q:sr_
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privateint pageSize = PAGESIZE; Oo0SDWI`(
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<?:
privateList items; q)j_QbW)
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privateint totalCount; tP][o494\&
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q
privateint[] indexes = newint[0]; bt{b%r
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privateint startIndex = 0; 0H/)wy2ym
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public PaginationSupport(List items, int JyO2P
SNJSRqWL/
totalCount){ dM=45$\q
setPageSize(PAGESIZE); tiGBjTPt
setTotalCount(totalCount); jP{&U&!i
setItems(items); 7,lnfCm H
setStartIndex(0); lsaA
} IE|? &O
@ tvz9N
public PaginationSupport(List items, int g&*,j+$ }
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totalCount, int startIndex){ s(Bcw`'#
setPageSize(PAGESIZE); hp1+9vEN
setTotalCount(totalCount); B[,AR"#b
setItems(items); uCr :+"C
setStartIndex(startIndex); ?o6X_UxW!
} M>_vsI^I'
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public PaginationSupport(List items, int QR2S67-
~].?8C.>*
totalCount, int pageSize, int startIndex){ @C|nc&E2s
setPageSize(pageSize); ObfRwZh?q
setTotalCount(totalCount); D3B]
setItems(items); 45?%D}
setStartIndex(startIndex); ?g9:xgkF
^
} j'k
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publicList getItems(){ /go|r '
return items; 6CCm1F{`
} Vel}lQD
%s! |,Cu
publicvoid setItems(List items){ H76iBJ66
this.items = items; dEZUK vo
} lrAhdi
]|-sZ<?<i
publicint getPageSize(){ '451H3LC0
return pageSize; b'W.l1]<-
}
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{
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publicvoid setPageSize(int pageSize){ 4[(NxXH8M
this.pageSize = pageSize; FUarI5#fwF
} kH5D%`Kw
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publicint getTotalCount(){ )q66^%;S
return totalCount; Cz)&R^
} s+?2oPa
gBky ZK
publicvoid setTotalCount(int totalCount){
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cn
if(totalCount > 0){ <iA\ZS:
this.totalCount = totalCount; W=#AfPi$&
int count = totalCount / ?-zuy US
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pageSize; P)kJ[Zv>f
if(totalCount % pageSize > 0) !
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count++; j^7A}fz
indexes = newint[count]; =?c""~7
for(int i = 0; i < count; i++){ hrm<!uKn
indexes = pageSize * au04F]-|j8
=W &Mt
i; V2!0),]B
} !~&&&85
}else{ /Kd7#@
this.totalCount = 0; l n\qvD_
} b[GhI+_
} lLp,sNAj
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publicint[] getIndexes(){ `%
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return indexes; -72EXO=|
} 'zM=[#!B
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publicvoid setIndexes(int[] indexes){ l>MDCqV
this.indexes = indexes; HhL;64OYa
} {#ynN`tLyF
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publicint getStartIndex(){ W|D
kq
return startIndex; ,sIC=V +
} A#6zINK#B
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publicvoid setStartIndex(int startIndex){ NJ)Dw`|%|)
if(totalCount <= 0) j)2I+[aoB
this.startIndex = 0; T8|5%Y
elseif(startIndex >= totalCount) Kp6 @?
this.startIndex = indexes s/=% kCo
4 sax
[indexes.length - 1]; }b1FB<e]
elseif(startIndex < 0) ":_II[FPY
this.startIndex = 0; IH;sVT$M
else{
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this.startIndex = indexes %rMCiz
=KUmvV*\
[startIndex / pageSize]; At"$Cu!k
} HT6 [Z1
} #n'.a1R
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publicint getNextIndex(){ `Bw]PO
int nextIndex = getStartIndex() + "bIb?e2h9G
X+C*+k,z
pageSize; ~%8P0AP
if(nextIndex >= totalCount) SfnQW}RGI
return getStartIndex(); ?0_<u4
else VD~5]TQ
return nextIndex; \4L ur
} 0eNdKE
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publicint getPreviousIndex(){ uMEM7$o
int previousIndex = getStartIndex() - vY-CXWC7
Vw1>d+<~-)
pageSize; }! EVf
if(previousIndex < 0) dgjK\pH`h
return0; Cjx4vP
else ;NR|Hi]
return previousIndex; A<ds+0
} uYMn VE"
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} >!t3~q1Cn
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抽象业务类 "5&"Ij,/
java代码: ^o{{kju
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/** [zx|3wWAX-
* Created on 2005-7-12 n.&7lg^X
*/ {+WBi(=W
package com.javaeye.common.business; w6i2>nu_O
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import java.io.Serializable; b^VRpv
import java.util.List; nwU],{(Hgr
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import org.hibernate.Criteria; {^z73Gxt,
import org.hibernate.HibernateException; (dq_,LI
import org.hibernate.Session; 5c` ;~
import org.hibernate.criterion.DetachedCriteria; AH#mL
import org.hibernate.criterion.Projections; -N*[f9EJB
import $6a9<&LP_
Gr\ ]6
org.springframework.orm.hibernate3.HibernateCallback; A?H#bRAs
import Hu"$)V
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org.springframework.orm.hibernate3.support.HibernateDaoS ]SCHni_
^eh.Iml'@
upport; +})QT FV
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import com.javaeye.common.util.PaginationSupport; 2g=
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public abstract class AbstractManager extends G*I
dd
HibernateDaoSupport { V: D;?$Jl
"V' r}>
privateboolean cacheQueries = false; &DWSf`:Hx
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privateString queryCacheRegion; e*2^
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publicvoid setCacheQueries(boolean -D~K9u]U_
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cacheQueries){ @Chl>s
this.cacheQueries = cacheQueries; `;j1H<L
} uO]D=Z\S(
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publicvoid setQueryCacheRegion(String ::>|[ND
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queryCacheRegion){ O2Qmz=%
this.queryCacheRegion = MJ JC6:
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queryCacheRegion; <[k3x8H'
} #c:s2EL
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publicvoid save(finalObject entity){ K1 "HJsj
getHibernateTemplate().save(entity); q`1tUd 4G
} TRi'l #m4
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publicvoid persist(finalObject entity){ 6TW<,SM
getHibernateTemplate().save(entity); ]`$6=)_X
} IU8zidn&
cb^IJA9}
publicvoid update(finalObject entity){ $VmV>NZ
getHibernateTemplate().update(entity); e3ZRL91c
} F_qApyU,7
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publicvoid delete(finalObject entity){ k* C69
getHibernateTemplate().delete(entity); l$gJ^Wf2gY
} A;;#]]48
@} r*KF-
publicObject load(finalClass entity, PaaMh[OmG
Z?+ )ox
finalSerializable id){ ,7B7X)m{3
return getHibernateTemplate().load P8YnKyI,.
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(entity, id); g=\(%zfsxr
} !0l|[c4 e>
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publicObject get(finalClass entity, xRWfZ3E#
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finalSerializable id){ \^(#b,k#
return getHibernateTemplate().get }rJqMZ]w
6|EOB~|
(entity, id); i3)3.WK^
} -9om,U`t
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publicList findAll(finalClass entity){ }ekNZNcuM
return getHibernateTemplate().find("from k M/:n
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" + entity.getName()); %`bs<ZWT
} 2?ue.1C
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publicList findByNamedQuery(finalString N6[Z*5efR
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namedQuery){ Z2W&_(^.h
return getHibernateTemplate r.?dT |A
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().findByNamedQuery(namedQuery); 4m\Cc_:jO
} iYLg[J"
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publicList findByNamedQuery(finalString query, q}_8iDO6
'@ 24<T]
finalObject parameter){ qg j;E=7
return getHibernateTemplate 2_Lu0Yrg
_oZ3n2v}@
().findByNamedQuery(query, parameter); -d?<t}a
} ~Xx}:@Ld
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publicList findByNamedQuery(finalString query, !v3d:n\W8
-n@,r%`UK
finalObject[] parameters){ <1vogUDW
return getHibernateTemplate l%V+]skS
lGet)/w;c
().findByNamedQuery(query, parameters); Y3|_&\v6
} <YCjo[(~
k Jz^\Re
publicList find(finalString query){ G9S3r3
return getHibernateTemplate().find qW3XA$g|j'
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(query); #+i5'p(4
} t^bh2$J
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publicList find(finalString query, finalObject ZHRMW'Ne
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parameter){ e0C_ NFS+
return getHibernateTemplate().find p>U= Jg
*"jlsI
(query, parameter); ga'G)d3oS
} #.FhN x
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public PaginationSupport findPageByCriteria c*w0Jz>@.7
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(final DetachedCriteria detachedCriteria){ n1x3q/~
return findPageByCriteria x[&)\[t
-f'&JwE0=
(detachedCriteria, PaginationSupport.PAGESIZE, 0); vqF=kB"P
} ]:#W$9,WL
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public PaginationSupport findPageByCriteria _Kli~$c& M
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(final DetachedCriteria detachedCriteria, finalint FrRUAoFO
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startIndex){ iDCQqj`
return findPageByCriteria ZKS]BbMZa
(j%"iQD
(detachedCriteria, PaginationSupport.PAGESIZE, eOb)uIF
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startIndex); t ,EMyZ
} 1Si$Q
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public PaginationSupport findPageByCriteria 9*s:Vff{
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(final DetachedCriteria detachedCriteria, finalint #/t+h#jG
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pageSize, .8|"@
finalint startIndex){ hBDmC_\~
return(PaginationSupport) M>*xbBl
f?QP(+M5.
getHibernateTemplate().execute(new HibernateCallback(){ FbCuXS=+`
publicObject doInHibernate #A~7rH%hi
@6y)wA9Yx
(Session session)throws HibernateException { V>4v6)N
Criteria criteria = Kciz^)'Z
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detachedCriteria.getExecutableCriteria(session); w,1*dn
int totalCount = K7,Sr1O `
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((Integer) criteria.setProjection(Projections.rowCount @><8YN^)%
*"V) hI5
()).uniqueResult()).intValue(); rLp0)Go
criteria.setProjection ] `;Fc8$
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(null); 0|mCk
List items = b:x~Jz#%2
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criteria.setFirstResult(startIndex).setMaxResults -c[fg+L9
p3IhK>
(pageSize).list(); IRsyy\[kp8
PaginationSupport ps = cj|Urt
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new PaginationSupport(items, totalCount, pageSize, 2t3)$\ylQp
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startIndex); O}z-g&e.U
return ps; s[t?At->
} %/r:iD
}, true); [n$6T
} L}tP_ *
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public List findAllByCriteria(final C:vVFU|4
' $"RQ=
DetachedCriteria detachedCriteria){ nz/cs n
return(List) getHibernateTemplate fjqd16{Q
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().execute(new HibernateCallback(){ \|
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publicObject doInHibernate XJA];9^
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(Session session)throws HibernateException { ? RID4xu!
Criteria criteria = +DYsBCVbag
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detachedCriteria.getExecutableCriteria(session); a6 "-,Kg
return criteria.list(); |u#7@&N1
} !{b4+!@p
}, true); rb]?"lizi
} a-NicjV#
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public int getCountByCriteria(final B|r'
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DetachedCriteria detachedCriteria){ %0%Tp
Integer count = (Integer) wT +\:y
T1(*dVU?
getHibernateTemplate().execute(new HibernateCallback(){ QVkrhwp
publicObject doInHibernate yKC1h`2
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(Session session)throws HibernateException { >LW}N!IBy
Criteria criteria = L fZF
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detachedCriteria.getExecutableCriteria(session); 4-oaq'//BT
return v4,Dt
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criteria.setProjection(Projections.rowCount m{r#o?
yV*4|EkvW
()).uniqueResult(); :a9
} +tJ 7ZR%
}, true); U|x#'jGo'
return count.intValue(); ]D,\(|
} xL"O~jTS
} 0!M'z
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用户在web层构造查询条件detachedCriteria,和可选的 S q{@4F}d
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 t8`wO+4@
8#/y`ul
PaginationSupport的实例ps。 X!m
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ps.getItems()得到已分页好的结果集 w/*m_O\!
ps.getIndexes()得到分页索引的数组 4eJR=h1
ps.getTotalCount()得到总结果数
w"C,oo3
ps.getStartIndex()当前分页索引 W6B"QbHYz
ps.getNextIndex()下一页索引 : [7O=[pk
ps.getPreviousIndex()上一页索引 ]J@-,FFC
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ;#:AM;
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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 y
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一下代码重构了。 w 5?D]u
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我把原本我的做法也提供出来供大家讨论吧: 5{Q9n{dOh
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首先,为了实现分页查询,我封装了一个Page类: 52zE -SY
java代码: e[s}tjx
*l=(?Pe<
} `5k^J$x
/*Created on 2005-4-14*/ 9\c]I0)3p
package org.flyware.util.page; 2`TV(U@
H2+b3y-1a]
/** @&Bh!_TWc
* @author Joa v?Utz~lQ
* {M5t)-
*/ qR_>41JU"
publicclass Page { .ESvMK~x
|`t 6lVO,Z
/** imply if the page has previous page */ *tgu@9b
privateboolean hasPrePage; G!;PV^6x
F"UI=7:o
/** imply if the page has next page */ se`Eez}
privateboolean hasNextPage; ~> Q9
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/** the number of every page */ 9)NKI02M|
privateint everyPage; oLh ,F"nB
8-B7_GoJ+B
/** the total page number */ ;o9ixmT<-o
privateint totalPage; \~"Ub"~I
}\Rmwm-
/** the number of current page */ o~)o/(>ox
privateint currentPage; "ayV8{m^3
%9a3$OGZX
/** the begin index of the records by the current 1P*hC<
kDMvTVd
query */ HE%/+mZN
privateint beginIndex; bWAa:
r
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/** The default constructor */ f!`?_
public Page(){ N)GHQlgH
G(TFv\`vH
} kM{8zpn
bXOKC
/** construct the page by everyPage dpw-a4o}
* @param everyPage ; Byt'S
* */ eNK[P=-
public Page(int everyPage){ oV0T
this.everyPage = everyPage; #Uu,yHMv:;
} W>C?a=r~
YnRO>`
/** The whole constructor */ "`V@?+3
public Page(boolean hasPrePage, boolean hasNextPage, BB\GrD
]JYE#F
,>h"~X
int everyPage, int totalPage, ;Pt8\X
int currentPage, int beginIndex){ /HpM17
this.hasPrePage = hasPrePage; +tT"
this.hasNextPage = hasNextPage; } &B6
this.everyPage = everyPage; ypx~WXFK
this.totalPage = totalPage; 7I
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this.currentPage = currentPage; j2<+[h-
this.beginIndex = beginIndex; ~TEn +
} .R)P
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/** \&hq$
* @return uR5+")r@S
* Returns the beginIndex. hm! J@
*/ <1l%|
publicint getBeginIndex(){ SL- 2 ^\R
return beginIndex; HS/.H,X
} .Y;f9R
_ZK^JS
/** N*}soMPV^.
* @param beginIndex N68$b#9Ry
* The beginIndex to set. k`8O/J
*/ t4_yp_
publicvoid setBeginIndex(int beginIndex){ B[GC@]HE
this.beginIndex = beginIndex; p%>sc
} 8%#8PLB2
X]p3?"7
/** OW4j!W
* @return qqf`z,u
* Returns the currentPage. Zek@xr;]
*/ WJhTU@'
publicint getCurrentPage(){ mG&A_/e!9
return currentPage; W3tin3__
} eV|N@
"dX~J3$
/** 4@@Sh`E:
* @param currentPage Vb`Vp(>AU
* The currentPage to set. E=ijt3
*/ |6JKB'
publicvoid setCurrentPage(int currentPage){ p|t" 4HQ
this.currentPage = currentPage; `xLsD}32
} GHcx@||C?
5lG\Z?
/** at_*Zh(
* @return ]u|v7}I4
* Returns the everyPage. U]sAYp^$
*/ SWV*w[X<X
publicint getEveryPage(){ U.Mfu9}#:
return everyPage; )OV0YfO
} [! $NTt_
Y7}Tuy dC
/** 7z4k5d<^_
* @param everyPage o{sv<$
* The everyPage to set. \dtiv& x
*/ -<s Gu9
publicvoid setEveryPage(int everyPage){ ^el+ej/=
this.everyPage = everyPage; \N*([{X
} 9E2iZt]
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/** 3}fOb
* @return CLrX!JV>
* Returns the hasNextPage.
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*/ U"k$qZ[
publicboolean getHasNextPage(){ -+rzc&h
return hasNextPage; W\~^*ny
P6
} ,IjZQ53q~
qgrJi +WZ
/** U|}
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* @param hasNextPage VV$t*9w
* The hasNextPage to set. ,/{e%J
*/ {JgY-#R?{(
publicvoid setHasNextPage(boolean hasNextPage){ gm-[x5O"
this.hasNextPage = hasNextPage; WPL@v+
} xak)YOLRV
}L_YpG7
/** Lb/GL\J)
* @return p@Y=6 Bw
* Returns the hasPrePage. .HS6DOQ
*/ oFWb.t9<
publicboolean getHasPrePage(){ t5-O-AI[b{
return hasPrePage; B}iEhWO6
} h3CA,$HJ
SndR:{
/** ODxZO3
* @param hasPrePage WTfjn|a
* The hasPrePage to set. m\`>N_4*9
*/ e2O6q05 ?Q
publicvoid setHasPrePage(boolean hasPrePage){ WA`A/`taT
this.hasPrePage = hasPrePage; :-1|dE)U
} R/hIXO
~lw9sm*2v2
/** *S.U8;*Xj
* @return Returns the totalPage. 5?7AzJl>
* h:?^0b!@
*/ _%nz-I
publicint getTotalPage(){ '#'noB;,
return totalPage; >pv.,cj
} 3_
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/** QKG3>lU
* @param totalPage 3Qy@^"
* The totalPage to set. q)k:pQ
*/ 3:+9H}Q
publicvoid setTotalPage(int totalPage){ ;]dD\4_hK
this.totalPage = totalPage; 'C[tPP
} 4ijtx)SA
N''QQBUD
} yKc-:IBb{u
u R0UfKK
b[74$W{
T`&zQQ6F'
rW{!8FhI
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 0pZvW
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个PageUtil,负责对Page对象进行构造: EgjJywNhd2
java代码: \2\{c1df
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9kL,69d2
/*Created on 2005-4-14*/ bv+u7B6,
package org.flyware.util.page; ){;XI2
b,xZY1a
import org.apache.commons.logging.Log; Xh9QfT ,
import org.apache.commons.logging.LogFactory; zPby+BP
n:5M
E*
/** 4zoQe>v~
* @author Joa '2(m%X\6
* HlGSt$woX
*/ R;< q<i_l
publicclass PageUtil { qe0 D[L
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privatestaticfinal Log logger = LogFactory.getLog 76nH)^%l<
GK@OdurAR
(PageUtil.class); 6r)P&J
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/** 'cD?0ou`o
* Use the origin page to create a new page +jLy>=u
* @param page G@8)3 @
* @param totalRecords H[=\_X1o(
* @return 8x{Owj:Q
*/ .biq)Le
publicstatic Page createPage(Page page, int Kj4/fB
]VI^ hhf
totalRecords){ ~7]V^tG
return createPage(page.getEveryPage(), *8}b&4O~
t-\+t<;
page.getCurrentPage(), totalRecords); Q0U~s\<
} wI%M3XaBws
B8@mL-Z-;
/** I
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* the basic page utils not including exception y'R}
fUT[tkb/!
handler ?UXFz'
* @param everyPage ":!$Jnj,
* @param currentPage :#rP$LSYC
* @param totalRecords -&Rv=q>
* @return page {;yO3];Hqw
*/ *;<fh,wOk
publicstatic Page createPage(int everyPage, int KWJVc
`
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currentPage, int totalRecords){ aacy5E
everyPage = getEveryPage(everyPage); pjeNBSu6
currentPage = getCurrentPage(currentPage); sZ `Tv[
int beginIndex = getBeginIndex(everyPage, AxEyXT( h5
&G{GLP?H
currentPage); &o:5lxR{
int totalPage = getTotalPage(everyPage, [M|^e;tWK
=*\s`ox`
totalRecords); ,-UF5U
boolean hasNextPage = hasNextPage(currentPage, KOcB#UHJ
Bkcwl
totalPage); z*.AuEK?
boolean hasPrePage = hasPrePage(currentPage); aKI"<%PNn
y=3 dGOFB
returnnew Page(hasPrePage, hasNextPage, P>/:dt'GJ}
everyPage, totalPage, o@meogkL
currentPage, }d[(kC_
^FVdA1~/
beginIndex); i)i>Ulj*i
} y{<e4{
!
"hIYf7r##
privatestaticint getEveryPage(int everyPage){ $WA wMS,
return everyPage == 0 ? 10 : everyPage; IiYL2JS;t|
} xR+vu>f
N`8K1{>BH
privatestaticint getCurrentPage(int currentPage){ -cgO]q+Oq
return currentPage == 0 ? 1 : currentPage; +H-=`+,
} 'HA{6v,y
)%(ZFn}
privatestaticint getBeginIndex(int everyPage, int E_,/)U8
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currentPage){ &#p1ogf:
return(currentPage - 1) * everyPage; s^kG]7
} QoD_`d
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privatestaticint getTotalPage(int everyPage, int ]H1mj#EWU
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totalRecords){ yD9enYM
int totalPage = 0; q;{(o2g
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if(totalRecords % everyPage == 0) 4_#$k{
totalPage = totalRecords / everyPage; 4I4m4^
else 6N/(cUXJ
totalPage = totalRecords / everyPage + 1 ; g )hEzL0k
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return totalPage; fc#9e9R
} U:7h>Z0W
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privatestaticboolean hasPrePage(int currentPage){ .$U,bE
return currentPage == 1 ? false : true; QV|6"4\
} JPI%{@Qc^
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privatestaticboolean hasNextPage(int currentPage, vs@d)$N
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int totalPage){ oz!)x\m*H
return currentPage == totalPage || totalPage == `z!AjAT-G
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0 ? false : true; ~Ntk-p
} T3w%y`K
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} 6-U_TV
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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。 xm m,-u
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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 @@Ib^sB%
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做法如下: AR |4^
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 91R#/i
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的信息,和一个结果集List: Wa;N(zw0h
java代码: O8;/oL4 U
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/*Created on 2005-6-13*/ W;u.@I&
package com.adt.bo; \Ec<ch[)c
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import java.util.List; tU4#7b:Y
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import org.flyware.util.page.Page; `>"#d
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/** PT>b%7Of
* @author Joa @A[)\E1
*/ *@rA7zPFf
publicclass Result { ]d*9@+Iu
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private Page page;
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private List content; gT}H B.
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/** Vgm*5a6t
* The default constructor XIcUoKg^
*/ ^".OMS"!
public Result(){ m?S;sew@5
super(); rm-d),Zt
} M=,pn+}y>
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/** b++r#Q
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* The constructor using fields XoN~d
* n|5\Q
* @param page [ycX)iM
* @param content |/,SNE
*/ "uH>S+%|b
public Result(Page page, List content){ 0i~U(qoI
this.page = page; l7QxngWw
this.content = content; ~,lt^@a
} ')jItje|
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/** -Y_,
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* @return Returns the content. S,5ok0R
*/ t$BjJ -G
publicList getContent(){ x?AG*'
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return content; yY VR]H H
} ~&Z>fgOTJ
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/** ) .KA0-
* @return Returns the page. 5]O{tSj
*/ gWj-@o\
public Page getPage(){ M 5#wz0
return page; [CQR
} SaPE 1^}
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/** joY7Vk!<