Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 iS
zw]3Vg{T
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 .fEwk
Ukc'?p,*
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 jn$j^51`C
wWTQ6~Y%d
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 '0RRFO
Ff<)4`J
。 &dRjqn^&X
ra:GzkIw
分页支持类: [/OQyb4F<
MtUY?O.P2
java代码: &2{]hRM
c|lU(Tf
#W|!fILL
package com.javaeye.common.util; IBET'!j4"
ufPCx|x~
import java.util.List; H* /&A9("
({e7U17[#
publicclass PaginationSupport { 2:'lZQ
BC({ EE~R)
publicfinalstaticint PAGESIZE = 30; DWrbp
]_u`EvEx6
privateint pageSize = PAGESIZE; Fg=v6j4W
sKd)BA0`
privateList items; bnr|Y!T}Bi
s@~/x5jwCs
privateint totalCount; hJ[UB
\f"1}f
privateint[] indexes = newint[0]; *S4aF*Qk
TKOP;[1h
privateint startIndex = 0; 1Nj=B_T
f=m/
-mAA
public PaginationSupport(List items, int o?wt$j-
l3p3tT3+
totalCount){ kOipH |.x
setPageSize(PAGESIZE); dE [Ol
setTotalCount(totalCount); 2.f|2:I
setItems(items); 9"ugz^uKt
setStartIndex(0); AS|Rd+.
} o1k#."wHr
QKccrAo
public PaginationSupport(List items, int FJwt?3\u5
7`fY*O6
totalCount, int startIndex){ Dtt-|_EMS
setPageSize(PAGESIZE); X*O9JGh
setTotalCount(totalCount); N09KVz2Q
setItems(items); =dGKF`tR
setStartIndex(startIndex); s}(X]Gx1
} ~ziexZ=N
E>}q2
public PaginationSupport(List items, int S+ebO/$>
b_vTGl1_6
totalCount, int pageSize, int startIndex){ 3dG4pl~
setPageSize(pageSize); <*Ub2B[m
setTotalCount(totalCount); .C= I^
setItems(items); 2-mQt_
i
setStartIndex(startIndex); /^2CGcT(
} E[?kGR[
nxQ}&n
publicList getItems(){ s$GF 95^
return items; Spgg+;9
} B 8{
uR
C:GvP>
publicvoid setItems(List items){ Qq3fZ=
this.items = items; `6F+Rrn
} G{o+R]Us
4ht\&2&:
publicint getPageSize(){ uyT/Xzo3
return pageSize; Rp/-Pv
} -H\,2FO
\r;F2C0*i
publicvoid setPageSize(int pageSize){ FH*RU1Z
this.pageSize = pageSize; ]XUSqai
} hYb9`0G"2
C`4gsqD;Z
publicint getTotalCount(){ .pvxh|V
return totalCount; <xlm
K(
} \hbiU]
|ym%|
B
publicvoid setTotalCount(int totalCount){ 0JXqhc9'
if(totalCount > 0){ ><Uk*mwL
this.totalCount = totalCount; T"!EK&
int count = totalCount / &Rp"rMeW
-t4
[oB
pageSize; 1TRN~#ix
if(totalCount % pageSize > 0) [/ohk&
count++; lLCdmxbT
indexes = newint[count]; #T \
for(int i = 0; i < count; i++){ 0M8.U
indexes = pageSize * &+r4
El6bD% \G
i; `^##b6jH
} te'*<HM
}else{ |4Ha?W
this.totalCount = 0; s'L?;:)dyB
} a+?~;.i~
} 'm O2t~n
Oh`2tc-
publicint[] getIndexes(){ (X}@^]lpa
return indexes; T~s}N x#
} 1V%'.l9
Wsm`YLYkt!
publicvoid setIndexes(int[] indexes){ bGv4.:)
this.indexes = indexes; p4>,Fwy2
} CLN+I'uX0
%S#WPD'Y
publicint getStartIndex(){ Hr
}k5'
return startIndex; jTSOnF}C~+
} 5 =Z!hQ}
Uix{"
publicvoid setStartIndex(int startIndex){ o6|-=FcvC
if(totalCount <= 0) Coa -8j*R7
this.startIndex = 0; f=I:DkR
elseif(startIndex >= totalCount) ~O4|KY
this.startIndex = indexes ~L4eZ
D;js.ZF
[indexes.length - 1]; Ze
?
g
elseif(startIndex < 0) 0ar=cuDm
this.startIndex = 0; |F!F{d^p
else{ ^l !L)iw
this.startIndex = indexes CV^c",b_
`="v>qN2\
[startIndex / pageSize]; AS;.sjgk
} G|9B)`S
} z{?4*Bq
yP\Up
publicint getNextIndex(){ T:!MBWYe |
int nextIndex = getStartIndex() + 509Q0 [k
QnKC#
pageSize; _Bk
U+=|J
if(nextIndex >= totalCount) ,7,;twKz
return getStartIndex(); m0( E kK
else i'tp1CI
return nextIndex; JBcY!dy-d
} TzM=LvA
#*,sa
publicint getPreviousIndex(){ [Ox(.
int previousIndex = getStartIndex() - Lko`F$5X
h&'=F)5
pageSize; F2>%KuM
if(previousIndex < 0) d6.}.*7Whc
return0; ?R6`qe_F
else 0BTLcEqgZ
return previousIndex; <_:zI r,
} @ajM^L!O
9]$`)wZ
} ((MLM3zJ
PXEKV0y
xncwYOz
ybvI?#
抽象业务类 B\_[R'Pf&
java代码: FH\CK
cY{Nos
+1@AGJU3
/** =A n`D
* Created on 2005-7-12 b5 Q NEi
*/ \Ph7(ik
package com.javaeye.common.business; jA`a/vWu
W_<4WG
import java.io.Serializable; iBvOJs
import java.util.List; ty-
r&
Q}P-$X+/ n
import org.hibernate.Criteria; \P?A7vuhLs
import org.hibernate.HibernateException; s4,(26y
import org.hibernate.Session; Tf-CEHWD
import org.hibernate.criterion.DetachedCriteria; uec|S\~M
import org.hibernate.criterion.Projections; }lfn0 %(@
import %v4
[{ =fE
)H+kB<n
org.springframework.orm.hibernate3.HibernateCallback; dAxp ,):&J
import XxOn3i
xo~g78jm7,
org.springframework.orm.hibernate3.support.HibernateDaoS +,_c/(P
mk= #\>
upport; S< x:t(
4/MNqit+
import com.javaeye.common.util.PaginationSupport; u~'OcO
YIOR$
public abstract class AbstractManager extends gX*K&*q
gaeOgP.0
HibernateDaoSupport { )N)ljA3]
rYGRz#:~+
privateboolean cacheQueries = false; _T]>/}}p
Q]\j>>
privateString queryCacheRegion; IJPgFZ7
[ud|dwP"
publicvoid setCacheQueries(boolean .,mPdVof
']?=[`#NL
cacheQueries){ J
Jy{@[m
this.cacheQueries = cacheQueries; p\S8oHWe
} `C'}e
afm_ Rrg[
publicvoid setQueryCacheRegion(String f z%tA39m
KXe
ka
queryCacheRegion){ ( V4G<-jG
this.queryCacheRegion = O5-;I,)H
x!?Z*v@I
queryCacheRegion; 'F5)ACA%
} :]c=pH
F<r4CHfh;
publicvoid save(finalObject entity){ ;r!\-]5$
getHibernateTemplate().save(entity); q^Inb)FeN
} ]{Ek[Av
xIgql}.
publicvoid persist(finalObject entity){ =|0/Ynfe
getHibernateTemplate().save(entity); l0`'5>
} dS$ji#+d$
fn1pa@P
publicvoid update(finalObject entity){ O71BM@2<
getHibernateTemplate().update(entity); s.y}U5Ty?P
}
g1qi\axm
8]C1K
Zs
publicvoid delete(finalObject entity){ 7) 0q--B
getHibernateTemplate().delete(entity); D5`(}
} b1=pO]3u
S=O$JP79
publicObject load(finalClass entity, bi,mM,N/
l* Y[^'
finalSerializable id){ 0N VI+Z$
return getHibernateTemplate().load 7@P656{
RpN <=
(entity, id); Qa?aL
} e\.HWV ]I
};p~A-E=
publicObject get(finalClass entity, Gl>E[iO
K:w]>a
finalSerializable id){ (1 yGg==W.
return getHibernateTemplate().get %#9P?COs&W
h,]+ >`b
(entity, id); xjrlc9
} A&
=pw#
oKiD8':
publicList findAll(finalClass entity){ q?iCc c
return getHibernateTemplate().find("from !4B_$6US
;[~^(.
f
" + entity.getName()); xBWx+My
} BWEv1' v
sVoR?peQ
publicList findByNamedQuery(finalString <[9?Rj@
(nz}J)T&
namedQuery){ :c<*%*e
return getHibernateTemplate SG`)PW?
~04[KG
().findByNamedQuery(namedQuery); )*
3bkKVB
} TkT-$=i
Y)OBTX
publicList findByNamedQuery(finalString query, M5u_2;3
_n_sfT6)B
finalObject parameter){ |."G ?*
return getHibernateTemplate 8m7;x/0ld
LE|<O
().findByNamedQuery(query, parameter); f9F2U
)
} ,D8&q?a
GLcd9|H
publicList findByNamedQuery(finalString query, $WClpvVj
* gHCy4u{
finalObject[] parameters){ nNs .,J)
return getHibernateTemplate [`9^QEj
*;X-\6
().findByNamedQuery(query, parameters); ;NG1{]|Z
} Gl;f#}
mt^`1ekoY
publicList find(finalString query){ \!4|tBKVY
return getHibernateTemplate().find ;q&0,B
/f]/8b g>
(query); GEfY^!F+
} U2UyN9:6F
- p^'XL*Z
publicList find(finalString query, finalObject P'F~\**5
^Po,(iIn
parameter){ )-#i8?y3C
return getHibernateTemplate().find `:gYXeR
b-uZ"Kf^
(query, parameter); 8~qlLa>jc
} ^k;mn-0
1b+h>.gWar
public PaginationSupport findPageByCriteria _'lmCj8L
UEN56@eCNf
(final DetachedCriteria detachedCriteria){ RxMoD.kx
return findPageByCriteria $^IjFdD
KcnjF^k
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 94YA2_f;
} 3 69Zu4|u
L}b'+Wi@
public PaginationSupport findPageByCriteria b?>VPuyBb
)r pD2H
(final DetachedCriteria detachedCriteria, finalint `/c@nxh
I3An57YV].
startIndex){ 5f{wJb2
return findPageByCriteria [x|)}P7%s
~.H~XKw
(detachedCriteria, PaginationSupport.PAGESIZE, 2$Wo&Q^_
Onyh1
startIndex); n5\}KZh
} <d S5|||
>'.[G:b
public PaginationSupport findPageByCriteria vuW-}fY;
_1\poAy
(final DetachedCriteria detachedCriteria, finalint ?f f
[$ab
G1TANy
pageSize, L,
#Byao
finalint startIndex){ IE}Sdeqi)
return(PaginationSupport) ?F25D2[(
eN4t1$
getHibernateTemplate().execute(new HibernateCallback(){ -zR.'x%
publicObject doInHibernate g kn)V~ij
>-eS&rma
(Session session)throws HibernateException { SNN#$8\
Criteria criteria = }9
?y'6l
]An_5J
detachedCriteria.getExecutableCriteria(session); xjE7DCmA
int totalCount = _V&x`ks
k3#wLJ
((Integer) criteria.setProjection(Projections.rowCount ZLuPz#
+2El
()).uniqueResult()).intValue(); 8,H~4Ce3
criteria.setProjection w7r'SCVh3+
1Lc8fP$
(null); @H6%G>K,
List items = m$)YYpX
1NW>wo
criteria.setFirstResult(startIndex).setMaxResults 8ZFH}v@V1'
shD+eHo$
(pageSize).list(); PH[4y:^DN
PaginationSupport ps = Agz=8=S%
IE|,~M2
new PaginationSupport(items, totalCount, pageSize, fmBkB8
9V.+U7\w
startIndex); /K[]B]1NE
return ps; ^SgN(-QH
} $.;iu2iyo
}, true); K('
9l& A
} vWuyft*
'Z y{mq\
public List findAllByCriteria(final ~RAzFLt6x
fs7~NY
DetachedCriteria detachedCriteria){ pRb<wt7v
return(List) getHibernateTemplate }&C dsCM>2
u6f4yQ
().execute(new HibernateCallback(){ A_aO}oBX
publicObject doInHibernate fG3wc
l~
L-j/R1fTvl
(Session session)throws HibernateException { y>4p~
Criteria criteria = 7WXiG0
$G)&J2zL
detachedCriteria.getExecutableCriteria(session); 75<el.'H
return criteria.list(); )Gmb?!/^
} 5%'o%`?i
}, true); Nz}|%.GP"
} $4sAnu]
80 dSQ"y
public int getCountByCriteria(final *u58l(&`8
<. ezw4ju
DetachedCriteria detachedCriteria){ BF>T*Z-Ki
Integer count = (Integer) 1xq3RD
%s]U@Ku(a
getHibernateTemplate().execute(new HibernateCallback(){ dP?nP(l
publicObject doInHibernate *q+oeAYX
Sb^a dd0dT
(Session session)throws HibernateException { {npOlV
Criteria criteria = \MF3CK@/
JATS6-Lz`
detachedCriteria.getExecutableCriteria(session); .V7Y2!4TE
return <1TlW
~q<
!,I7 ?O
criteria.setProjection(Projections.rowCount ZBPd(;"x+
LAj}kW~
()).uniqueResult(); Oib[\O7[z
} bN]\K/
}, true); O}e|P~W
return count.intValue(); (\T8!s{AO
} w{RNv%hJ$=
} q/A/3/
O 0Vn";Q 4
)j]gm i"
V|+ `L-
HI}pX{.\
Z3OZPxm
用户在web层构造查询条件detachedCriteria,和可选的 ,G/\@x%
8}Fw%;Cb
startIndex,调用业务bean的相应findByCriteria方法,返回一个 zuK/(qZ
z]'|nX
PaginationSupport的实例ps。 |~7+/VvI+
USlF+RY@3L
ps.getItems()得到已分页好的结果集 ,w,ENU0~f
ps.getIndexes()得到分页索引的数组 xhw8#
ps.getTotalCount()得到总结果数 [Od>NO,n+]
ps.getStartIndex()当前分页索引 vx({N?
ps.getNextIndex()下一页索引 4x=V|"
ps.getPreviousIndex()上一页索引 Pn~pej5'K
8XLxT(YFIs
Y:DNu9
.CIbpV?T
3L'en
F<6KaZ|
#|)JD@;Q
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 t-3v1cv"
yg]suU<z]
,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 53g8T+`\(
>xhd[
一下代码重构了。 dt`9RB$
oG|?F4l*
我把原本我的做法也提供出来供大家讨论吧: ykErt%k<n
E
geG,/-`
首先,为了实现分页查询,我封装了一个Page类: 23(B43zy
java代码: ,-w-su=J_
`I]1l MJ)o
hY\Eh.
/*Created on 2005-4-14*/ Q
`J,dzY
package org.flyware.util.page; L,s|gtv
QO1A976o
/** 6i*ArGA
* @author Joa S3%.-)ib
* .WN;TjEg!
*/ I!C(K^
publicclass Page { WLg6-@kxXs
-o=P85V
/** imply if the page has previous page */ eXskwV+7
privateboolean hasPrePage; r6gt9u:
@m !9"QhC
/** imply if the page has next page */ @&nx;K6h
privateboolean hasNextPage; ^.pE`l%1}
[ZL r:2+z
/** the number of every page */ B|Rpm^|
privateint everyPage; &0;{lS[N:L
P#vv+]/
/** the total page number */ 3B!&ow<rt
privateint totalPage; N}.Q%&6:
l<0[ K(
/** the number of current page */ )A>U<n $h
privateint currentPage; Zi[{\7a
wiK@o$S-
/** the begin index of the records by the current lOowMlf@2
W TXD4}
query */ ZNL;8sI?>
privateint beginIndex; `? 9]'
Z9;nC zHm
qd#(`%_/
/** The default constructor */ ]yj4~_&O
public Page(){ #Tgz,e9
(Fbm9(q$d
} } K+Q9<~u
hJ$C%1;
/** construct the page by everyPage jm#F*F vL
* @param everyPage Q G=-LXv:@
* */ MA/"UV&M(
public Page(int everyPage){ VOowA^
this.everyPage = everyPage; !}Woo$#ND
} *pS7/Qe
q N[\J7Pz9
/** The whole constructor */ 5'{qEZs^QU
public Page(boolean hasPrePage, boolean hasNextPage, :*F3
PpJE|[]
$BR=IYby
int everyPage, int totalPage, %%-U.
int currentPage, int beginIndex){ ^2Fs)19R
this.hasPrePage = hasPrePage; 7YQK@lS
this.hasNextPage = hasNextPage; !~w6"%2+7
this.everyPage = everyPage; ?@g;[310`
this.totalPage = totalPage; PJSDY1T
this.currentPage = currentPage; QYf/tQg$
this.beginIndex = beginIndex; &4[#_(pk
} ~Uwr689N
rlUdAa3
/** Up!ZCZ$RC
* @return <x>k3bD
* Returns the beginIndex. 5m%baf2_
*/
alb+R$s
publicint getBeginIndex(){ ]"2 v7)e
return beginIndex; 3 -_U-:2"
} :xAe<Pq
Z)6nu)
/** ]U^d 1&k
* @param beginIndex Dbkuh!R
* The beginIndex to set. H>X\C;X[
*/ ;I`,ZKY
publicvoid setBeginIndex(int beginIndex){ |Ad6~E+aL-
this.beginIndex = beginIndex; gvRc:5B[
} QU,TAO
&)"7am(S`
/** nM (=bEX
* @return Hq"<vp
* Returns the currentPage. '7O{*=`oj
*/ WV!kA_
publicint getCurrentPage(){ s:m<(8WRw
return currentPage; tsSS31cv
} eN2k8=
5>4A}hSe
/** 3q.[-.q
* @param currentPage .olPm3MC
* The currentPage to set. 1$3XKw'
*/ J.1ln
=Y
publicvoid setCurrentPage(int currentPage){ S\{^LVXTMd
this.currentPage = currentPage; ~d#;r5>
} Y+"hu2aPkY
[ilv/V<
/** d6d(?"
* @return x9o^9QJh
* Returns the everyPage. xJH9qc ME
*/ -Y jv&5
publicint getEveryPage(){ 0@mX4.!
return everyPage; l~Wk07r3
} yZ(Nv $[5
yK>0[6l
/** q:~`7I
* @param everyPage 3Ld ;zW
* The everyPage to set. +{Vwz
*/ sKB-7
publicvoid setEveryPage(int everyPage){ a m k42
this.everyPage = everyPage; ubN"(F:!-S
} SU#P.y18%
<
jocfTBk
/** Zm8
u:
* @return +'&_V011<
* Returns the hasNextPage. I}G}+0geV
*/ /YugQ.>| l
publicboolean getHasNextPage(){ }Cq9{0by?a
return hasNextPage; sh))[V"8
} @<w9fzi
vA7jZw
/** A2O_pbQti
* @param hasNextPage e=F( Zf+1^
* The hasNextPage to set. 9snyX7/!L
*/ '__3[D
publicvoid setHasNextPage(boolean hasNextPage){ ZNH*[[Pf
this.hasNextPage = hasNextPage; GT\s!D;<
} 3RH#e1Y
f{ 4G
/** v[yTk[zd0
* @return hZ\W ?r
* Returns the hasPrePage. U0bEB
*/ 'B<qG<>
publicboolean getHasPrePage(){ m5;[,He
return hasPrePage; {@K2WB
} Sc"4%L
vL=--#
/** 6`5
@E\"E
* @param hasPrePage #ZnX6=;X
* The hasPrePage to set.
xV 1Z&l
*/ 3_eml\CY
publicvoid setHasPrePage(boolean hasPrePage){ Xx<&6
4W
this.hasPrePage = hasPrePage; )}it,<
} <QoE_z`76
7%"\DLA
/** &_^*rD~
* @return Returns the totalPage. @Jn:!8U0
* qxcBj
*/ Y /ac}q
publicint getTotalPage(){ d
@kLLDP
return totalPage; LX?r=_\
} (#l_YI
-
G$kwc
F'C
/** DGfQo5#
* @param totalPage , ZP3F+XKb
* The totalPage to set. >\oJ&gdc
*/ I&NpN~AU
publicvoid setTotalPage(int totalPage){ IweK!,:>dN
this.totalPage = totalPage; $Ex 9
} ]pP2c[;
16> >4U:Y
} =&b$W/l)0
-S3+
h$Y8
UV8r&O
8W<)c
3;l>x/amk
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 ?kFCYZK|"
ZM^;%(
个PageUtil,负责对Page对象进行构造: T[[
java代码: /,@v"mE7c!
tfKeo|DM"
z&vms
/*Created on 2005-4-14*/ Qu>zO !x
package org.flyware.util.page; y=qo-v59'
n]fbV/ x
import org.apache.commons.logging.Log; 5eSTT#[+R
import org.apache.commons.logging.LogFactory; &@iF!D\u
DMxS-hl
/** t-x"(
* @author Joa |mE+f]7$
* H|:)K^o
*/ P$
dgO
publicclass PageUtil { Z
*<x
aC
}1]7
privatestaticfinal Log logger = LogFactory.getLog &b6@_C9
42LXL*-4
(PageUtil.class); j.N\U#3KK
8*PAgPj a
/** wfTv<WG,.E
* Use the origin page to create a new page ?uX6X'-
* @param page v9` B.(Ru
* @param totalRecords ~)8i5p;P/k
* @return |Ge/|;.v`
*/ 3a)Q:#okD
publicstatic Page createPage(Page page, int R}6la.mQ
Tocdh.H|
totalRecords){ n_&)VF#n(
return createPage(page.getEveryPage(), %s :
H_=[~mJ
page.getCurrentPage(), totalRecords); nzJi)A./
} `0XbV A
V>uW|6
/** 2xdJ(\JWM
* the basic page utils not including exception -qP[$Q
fQ_8{=<-&X
handler lnSE+YJ>
* @param everyPage o4'4H y
* @param currentPage aq \TO?
* @param totalRecords @wgGnb)
* @return page AG\852`1m
*/ }ZVv
publicstatic Page createPage(int everyPage, int BOQV X&g%
si.a]k/f
currentPage, int totalRecords){ ~(L +4]
everyPage = getEveryPage(everyPage); [K@!JY
currentPage = getCurrentPage(currentPage); ~)IJE+e>}
int beginIndex = getBeginIndex(everyPage, WJ4UJdf'
"v(]"L
currentPage); `/ReJj&~
int totalPage = getTotalPage(everyPage, uWtS83i
)[X!/KR90
totalRecords); )bU")
boolean hasNextPage = hasNextPage(currentPage, fvMhq:Bu
KP-z
totalPage); IeI%X\G
boolean hasPrePage = hasPrePage(currentPage); NWwtq&pz2
0Ilvr]1a4
returnnew Page(hasPrePage, hasNextPage, 35kbE'
everyPage, totalPage, OSi9J.]O
currentPage, UZ3Aq12U}a
\bA'Furp
beginIndex); d]~1.i
} $<e .]`R
pz}hh^]t
privatestaticint getEveryPage(int everyPage){ tUF]f6
return everyPage == 0 ? 10 : everyPage; Zw
8b
-_
} bK%tQeT
xQ
3u
privatestaticint getCurrentPage(int currentPage){ t\d;}@bl
return currentPage == 0 ? 1 : currentPage; M]TVaN$v#
} c
O>:n
6@ ^`-N;
privatestaticint getBeginIndex(int everyPage, int vS__*}^
|F{E4mg(o
currentPage){ rPvX8*)tV
return(currentPage - 1) * everyPage; ,;pX.Ob U
} V*uu:
t
U=b~
privatestaticint getTotalPage(int everyPage, int 'wV26Dm
V="f)'S$
totalRecords){ *LdH/C.LIf
int totalPage = 0; QO1Gq9
pytfsVM
if(totalRecords % everyPage == 0) TFNU+
totalPage = totalRecords / everyPage; VZbIU[5
else ^F9zS`Yz2
totalPage = totalRecords / everyPage + 1 ; R*eM 1
2#}IGZ`Yp/
return totalPage; qA/3uA!z
} b+apN ph
`^k<.O
privatestaticboolean hasPrePage(int currentPage){ MtTHKp
return currentPage == 1 ? false : true; L>GYj6D9
} O[B_7
<!XnUCtV
privatestaticboolean hasNextPage(int currentPage, luog_;{h+
P,=J"%a -
int totalPage){ HcS^3^Y
return currentPage == totalPage || totalPage == F4(U~n<
,.MG&O
0 ? false : true; 8>;o MM
} "E!p1
"fd=(&
M*l
ui0(#2'h%
} D ,^
U%<`
\ jdO,-(
4tNgK[6M
8@
gD03
*.Hnt\4|
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。 ~x|Sv4M
?|yJ#j1=
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 I3b-uEHev
}kefrT
做法如下: *X5LyO3-gP
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 |q)Q<%VS'
A~SSu.L@
的信息,和一个结果集List: Mn;CG'FA
java代码: c4W"CD;D
90D.G_45
X]%4QIeS
/*Created on 2005-6-13*/ o;/F=Zp
package com.adt.bo; :8T@96]P
U<byR!qLie
import java.util.List; (7!(e
,
vG:,oB}
import org.flyware.util.page.Page; v3#47F)
vjS7nR"T
/** g&5VorGx
* @author Joa 0k]N%!U
*/ sRI8znus
publicclass Result { `P*j~ZLlXN
/^ 7
9|$E
private Page page; kIo?<=F8T
e$I:[>
private List content; -q|M=6gOs
)+R3C%
/** HXo'^^}q;
* The default constructor 5|z[%x~f
*/ $7g(-W
public Result(){ ^@eCT}p{
super(); zxHfQ(
} Y:BrAa[
24l9/v'
/** K*RRbtb
* The constructor using fields FQ^uX]<3j
* ^S$w,
* @param page 5OE?;PJ(
* @param content ?q`mr_x%?
*/ r${a
S@F
public Result(Page page, List content){ ^r$5];n
this.page = page; $yJfAR
this.content = content;
rMloj8O*
} CKgyv%T5m:
wu'60po
/** izA3 INT
* @return Returns the content. ZH:X4!
*/ UQr+\ u
publicList getContent(){ I!~Omr@P
return content; 6h8NrjX
} a)b@en;v
mAKi%)
/**
A(5?
ci
* @return Returns the page. qpCi61lTDJ
*/ vi|ASA{V
public Page getPage(){ U {v_0\ES
return page; Gu=bPQOj
} {'[1I_3
L}nc'smvM
/** '(*D3ysU
* @param content a[De
* The content to set. YSmz)YfX9
*/ 4 -W?u51"
public void setContent(List content){ h~t]WN
this.content = content; UzXbaQQ2g
} >dY"B$A>
lN"rhZ
/** UI'eD)WR
* @param page huE#VY
/t
* The page to set. Uy=eHwU?J
*/ q~lW
publicvoid setPage(Page page){ <u\G&cd_tA
this.page = page; .=S{
} )vzT\dQ|
} @"0qS:s]X
aleIy}"
i"@?eq#h
V;=T~K|)>
5E8PbV-l
2. 编写业务逻辑接口,并实现它(UserManager, zwS'AN'A
g!UM8I-$
UserManagerImpl) J4; ".Y=
java代码: dl4.jLY
L2%P
q\<vCKI-^
/*Created on 2005-7-15*/ oY: "nE
package com.adt.service; ;MD{p1w
3 -FNd~%
import net.sf.hibernate.HibernateException; ^4:= b
usip>y
import org.flyware.util.page.Page; Ws(>}
qjy
Sl#XJ0 g
import com.adt.bo.Result; <rI~+J]s
czzV2P/t}
/** ] $*cmk(Y
* @author Joa &0`L; 1R
*/ h2]Od(^[
publicinterface UserManager { ub%q<sE*
&r_B\j3
public Result listUser(Page page)throws K||85l?<
_ev^5`>p/
HibernateException; I/l]Yv!
%JZIg!
} 1C{~!=6#
7E'C o|
$- L)>"
s*@.qN
w;"'l]W
java代码: f &|SGD*
\l~h#1|%;s
6pse@x?
/*Created on 2005-7-15*/ zc"eSy< w$
package com.adt.service.impl; LY MfoXp
+}n]A^&I\E
import java.util.List; i
F Ab"VA
5`J.
ic
import net.sf.hibernate.HibernateException; $H}Q"^rs
<t Nx*ce5
import org.flyware.util.page.Page; jZGmTtx
import org.flyware.util.page.PageUtil; 9}-,dgAB
8b/yT4f
import com.adt.bo.Result; (|-/S0AV
import com.adt.dao.UserDAO; q$K~BgFzpZ
import com.adt.exception.ObjectNotFoundException; |v+b?@
import com.adt.service.UserManager; > jcNo3S
=uH`EkY:
/** bCsQWsj^NW
* @author Joa dNR4h
*/ |@+
x9|'W
publicclass UserManagerImpl implements UserManager { :;EzvRy
Nuj%8om6
private UserDAO userDAO; J_,y?}.e3
8K qv)FjB
/** !O\r[c
* @param userDAO The userDAO to set. '*pq@|q;t
*/ 8PQ& 7o
publicvoid setUserDAO(UserDAO userDAO){ `` ={FaV~m
this.userDAO = userDAO; laAG%lq/'
} D 6(w}W
6Yklaq5
/* (non-Javadoc) wo/H:3^N
* @see com.adt.service.UserManager#listUser `is6\RH
w-1CA{"i7
(org.flyware.util.page.Page) i^8Zp;O"f
*/ 4-o$OI>
public Result listUser(Page page)throws rpd3Rp
22GtTENd1h
HibernateException, ObjectNotFoundException { gaJS6*P#
int totalRecords = userDAO.getUserCount(); h)w<{/p(
if(totalRecords == 0) _Nd\Cm
throw new ObjectNotFoundException 79Iz,_
|Q{ l]D
("userNotExist"); kmf4ax
h1
page = PageUtil.createPage(page, totalRecords); 8=$@azG
List users = userDAO.getUserByPage(page); eI@O9<.&
returnnew Result(page, users); c;Li~FLR
} (C!fIRY
kAqk~.
} K3jno+U&
e}kG1C8
6>l-jTM
|YH1q1l
Yy&0b(m U
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 2$jY_{B+x
ZnQnv@{8l
询,接下来编写UserDAO的代码: 6Cibc.vt
3. UserDAO 和 UserDAOImpl: dM
QnN[d6
java代码: 4m~\S)ad
.EI/0"^
J%nJO3,
/*Created on 2005-7-15*/ X/@Gx 4
package com.adt.dao; pgI@[zp7
sg3%n0Ms.W
import java.util.List; k07O.9>
{r Gx*<e
import org.flyware.util.page.Page; xH92=t-w
@x)z" )>
import net.sf.hibernate.HibernateException; ': HV9]k
mCg 5-E~;
/** '0[l'Dt'
* @author Joa |/q *Fg[f
*/ L)Kn8
publicinterface UserDAO extends BaseDAO { PoC24#vS
#0weN%
publicList getUserByName(String name)throws $u>^A<TBN
U\ 51j
HibernateException; r!(~Y
A
ieObo foD
publicint getUserCount()throws HibernateException; [}FP_Su$6
~!UxmYgO
publicList getUserByPage(Page page)throws \A':}<Rj
K\ZKVn
HibernateException; .[~E}O
^b&aDm~(7
} m0 `wmM
%F03cI,
py)V7*CgH
o'W &gkb9
@#sQ7eMoy
java代码: keX0br7u_
~,ac{%8x
M5D,YC3<
/*Created on 2005-7-15*/ *@n%K,$v
package com.adt.dao.impl; K~[/n<ks
Qg3
-%i/@
import java.util.List; olh|.9Kdj}
xe}"0'g
import org.flyware.util.page.Page; I 5
?onZ:s2
import net.sf.hibernate.HibernateException; @T1-0!TM')
import net.sf.hibernate.Query; MYLq2g\
4/HyO\?z5
import com.adt.dao.UserDAO; ww=< =
iHTxD1D+H
/** eqXW|,zUm
* @author Joa a
"8/y4Y
*/ o6'`W2P
public class UserDAOImpl extends BaseDAOHibernateImpl GAQVeL1
~bgFU
implements UserDAO { R9{6$djq\:
E-l>z%
/* (non-Javadoc) &7}-Xvc
* @see com.adt.dao.UserDAO#getUserByName HAP9XC(F]
^m?h .
(java.lang.String) -Ndd6O[ a5
*/ 6=FF*"-6E
publicList getUserByName(String name)throws aY6]NpT
V[CS{Hy'
HibernateException { he
9qWL&^G
String querySentence = "FROM user in class k4eV*e8
Rg+V;C
C~
com.adt.po.User WHERE user.name=:name"; xqLLoSte
Query query = getSession().createQuery GQT|T0>Ro
J1g
`0XH
(querySentence); 4uD!-1LT@
query.setParameter("name", name); c}$?k@=
return query.list(); z;1yZ4[G
} ]l`?"X|^
/Eu[7
/* (non-Javadoc) `}s)0 /}6
* @see com.adt.dao.UserDAO#getUserCount() u6|P)8?`
*/ PJO +@+"{@
publicint getUserCount()throws HibernateException { `[[
A7
int count = 0; pM.>u/=X
String querySentence = "SELECT count(*) FROM Iy\K&)5?
Xq,{)G%9nM
user in class com.adt.po.User"; h2K1|PUKl[
Query query = getSession().createQuery =f?| f
u:<%!?
(querySentence); ,253'53W)
count = ((Integer)query.iterate().next JoIffI?{(D
*=)%T(^
()).intValue(); yn"8Ma*
return count; eCdMDSFO3
} Ig*!0(v5$
x>7}>Y*(
/* (non-Javadoc) HtPasFrJ
* @see com.adt.dao.UserDAO#getUserByPage UjUDP>iz.>
]#KZ
W)M
(org.flyware.util.page.Page) Ez+.tbEA,
*/ XoL9:s(m~
publicList getUserByPage(Page page)throws ;}WdxWw4
`TBau:E lI
HibernateException { LQ373
j-
String querySentence = "FROM user in class ~O&3OL:L
Cz8=G;\
com.adt.po.User"; g/J
^YT!
Query query = getSession().createQuery Q(>89*b&
XF'K dz>p
(querySentence); BPwFcT)i!(
query.setFirstResult(page.getBeginIndex()) FNtcI7
.setMaxResults(page.getEveryPage()); 44]/rP_m
return query.list(); 9^x'x@6
} &qF
Q3'\Vj,S&
} WR%x4\,d#
0Evq</
fMP$o3;
-}4<P}.5T
K9:I8E<
至此,一个完整的分页程序完成。前台的只需要调用 hZU@35~BN
=T|Z[/fto
userManager.listUser(page)即可得到一个Page对象和结果集对象 Tz:mj
k[&+Iy
的综合体,而传入的参数page对象则可以由前台传入,如果用 ]|@RWzA
Xq` '^)
webwork,甚至可以直接在配置文件中指定。 mtvfG
uR"(0_
下面给出一个webwork调用示例: UW88JA0
java代码: $
nx&(V
IhhB^E|
IJhJfr0)Oo
/*Created on 2005-6-17*/ E}00y%@*J
package com.adt.action.user; cL?FloPc*
M\ B A+
import java.util.List; j:0(=H!#
gR
)xw)!
import org.apache.commons.logging.Log; ~kj1L@gy
import org.apache.commons.logging.LogFactory; W4Tuc:X5
import org.flyware.util.page.Page; tn>$5}^;
4U(W~O
import com.adt.bo.Result; UMuRB>ey
import com.adt.service.UserService; 0L9z[2sj
import com.opensymphony.xwork.Action; tH`!?
PVC\&YF
/** QI0d:7!W1
* @author Joa -NGY+1
*/ i?.MD+f8
publicclass ListUser implementsAction{ h%|Jkx!v-t
-U`]/
privatestaticfinal Log logger = LogFactory.getLog ]X ,f
gf$5pp-
(ListUser.class); KU|dw^Y k
}'U"HHv
private UserService userService; /J")S?. [u
WPPz/c|j
private Page page; MdV-;uf
}\!&3^I
privateList users; $<xa "aN!
vc0'x4
/* 9TuE.
* (non-Javadoc) G|*^W;(Z
* HN9!~G
* @see com.opensymphony.xwork.Action#execute() S:"R/EE(
*/ p(-f $Q(
publicString execute()throwsException{ IxNY%&* `
Result result = userService.listUser(page); eo.y,U h
page = result.getPage(); 38ChS.(
users = result.getContent(); %9cu(yc*}
return SUCCESS; _ +q.R
} kC"lO'
z%Pbs[*C
/** (,z0V+!
* @return Returns the page. Dl_y[9
*/ Y]!8Ymuww@
public Page getPage(){ -!zyit5B
return page; ZJlmHlAX
} } Wx#"6
!#wd~: H
/** mF7T=pl
* @return Returns the users. k`[ L
*/ u2%/</]h
publicList getUsers(){ MY1s
return users; 1n|)05p
} l?F-w;wHN
Ss ;C1:
/** cK6M8:KW
* @param page ZU\TA|
* The page to set. =
zJY5@^'7
*/ ME4Ir
publicvoid setPage(Page page){ t_%6,?S6
this.page = page; MDI[TNYG
} o_C
j o
t F^|,9_<
/** eJD!dGa
* @param users /|v:$iH,C
* The users to set. z'FD{xdf
*/ gwHNz5 a*V
publicvoid setUsers(List users){ TNs;#Q
this.users = users; }$E cNm$%
} vd+yU9
?+EN.P[;3
/** CDOqdBQ
* @param userService N4y$$.uv2
* The userService to set. M8j%bmd(,
*/ $$QbcnOf$
publicvoid setUserService(UserService userService){ 2\
3}y(
this.userService = userService; (NPDgR/
} Pt<lHfd
} 5R6@A?vr
ETQ.A< v
H3<
`
DY]\@<ez
;`ZGiax
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, Id-?her>B
V0y Q
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 t<'-?B2g
^@V$'Bk
么只需要: >:7W.QLRU
java代码: )<W6cDx'H+
F=}-ngx8&
nU]4)t_o\
<?xml version="1.0"?>
=FZt
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork F@=)jrO=$
|/LCwq%
1.0//EN" "http://www.opensymphony.com/xwork/xwork- V *2=S
f?xc-lX5R
1.0.dtd"> n- cEa/g
49Sq)jd<
<xwork> G}.t!"
<3]Qrjl
,b
<package name="user" extends="webwork- 8'c_&\kdv
-4:L[.2
interceptors"> =l%"Om*A
ZT@a2:&
<!-- The default interceptor stack name |cZKj|0>
Id->F0x0
--> )dFTH?Mpo
<default-interceptor-ref >we/#C"x
[ Tv!Pc
name="myDefaultWebStack"/> 8!e1T,:b
`a.1Af;L
<action name="listUser" tF> ?]
W/Rb7q4v
class="com.adt.action.user.ListUser"> 0:<dj:%M
<param +{* @36A5A
Q=hf,/N
name="page.everyPage">10</param> Mq7d*Bgb
<result [;5?=X,LD
mRIW9V
name="success">/user/user_list.jsp</result> JvFU7`4@
</action> i,G )kt'H
&W1{o&
</package> rw*#ta
O
@WuB&uF=d
</xwork> Rb_HD
Epm'u[wV
neC]\B[Xm
U4hsbraz
S9Kay'.aJ(
lH_S*FDa
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 ,$ICv+7]
"WKE%f
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 J?Kgev%
0q%=Vs~@g
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 _J}vPm
{ZK"K+;h
%dXf C!
~O{sOl
_<4
L|DSEth
我写的一个用于分页的类,用了泛型了,hoho WFBg3#p
Q^qG=
java代码: x)@G+I\u
mUi|vq)`=D
sePOW#|
package com.intokr.util; 0-dhGh?.
oh{!u!L`]
import java.util.List; z_XI,u}
pf.T{/%
/** G6X
* 用于分页的类<br> 4i'2~w{/
* 可以用于传递查询的结果也可以用于传送查询的参数<br> d OY+| P\
* h[d|y_)f
* @version 0.01 [MM11K
* @author cheng 3mWd?!+m=
*/ #mqz*=L3
public class Paginator<E> { ~g2ColFhu
privateint count = 0; // 总记录数 ~mUP!f
privateint p = 1; // 页编号 |L{<=NNs:D
privateint num = 20; // 每页的记录数 `m5cU*@D
privateList<E> results = null; // 结果 htg+V-,
rn1FCJ<;H
/** ?5m[Qc(<
* 结果总数 '{EBK
*/ A0*u(15%
publicint getCount(){ QsYc 9]:
return count; 'Mjbvh4
} SJVqfi3A
8xUmg&
publicvoid setCount(int count){ &,':@OQ
this.count = count; (bo{vX
} Tr}@fa
Rkfr4
/** O'JH=
'
* 本结果所在的页码,从1开始 8<u_ wt@
* 6.tppAO+
* @return Returns the pageNo. 6USet`#
*/ BzH7E[R49
publicint getP(){ ]zVe% Wa
return p; UC*<]
} [_j.pMH/P
FE1dr_i
/** ,2?"W8,
* if(p<=0) p=1 DSix(bs9
* M3 8,SH<
* @param p Ai iOs?
*/ v
F L{j
publicvoid setP(int p){ avls[Bq
if(p <= 0) }vO^%Gd
p = 1; }/G~"&N[
this.p = p; {rOz[E9vm
} Ks09F}
S5RS?ya
/** iXC/?
EK4
* 每页记录数量 U^ BB|
*/ O*oL(dk*8L
publicint getNum(){
3 Yl[J;i
return num; =_cWCl^5
} hmkcWr`
<2y~7h:
/** j^ZpBN L
* if(num<1) num=1 r jU $*+
*/ yB}y' 5
publicvoid setNum(int num){ _*Vq1D ]C
if(num < 1) -GP+e`d
num = 1; 13A11XTp
this.num = num; 7w)#[^
} C%#C|X193
Xu HJy
/** {NE;z<,*:
* 获得总页数 /eR @&!D '
*/ ~C=`yj
publicint getPageNum(){ Fg4eIE-/M
return(count - 1) / num + 1; wr*A%:
} >C_! }~
(m3p28Q?
/** ) !ZA.sx
* 获得本页的开始编号,为 (p-1)*num+1 R|!4Y`
*/ w_eu@R:u@
publicint getStart(){ CNcH)2Mk
return(p - 1) * num + 1; 0e8)*2S
} m{Q{ qJ5>
6?}8z
q[
/** 6@o_MtI
* @return Returns the results. Jb $PlOQ
*/ OAw/
publicList<E> getResults(){ Q*$x!q
return results; /[nt=#+
} J+?xfg
\ox:/-[c\<
public void setResults(List<E> results){ C& Nd|c
this.results = results; a((5_8SX5
} 3 ;.{
O%bX
RW>Z~Nj
public String toString(){ ? dSrY
StringBuilder buff = new StringBuilder +}4vdi"
,O
a)
(); oF
V9t{~j
buff.append("{"); [W{`L_"
buff.append("count:").append(count); x+yt|
&B
buff.append(",p:").append(p); Mw'd<{
buff.append(",nump:").append(num); :g<dwuVO
buff.append(",results:").append AH=6xtS-
Y<#7E;aL
(results); ?\\
]u
buff.append("}"); h"%6tpV-
return buff.toString(); >)N,V;j
} L/nz95
*o"F.H{#N
} +<
BAJWU
_Zf1=&U#/
8Yq6I>@!