Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 R>iRnrn:-
,X05&'@Z
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 '
R!pc
oWu2}#~z_
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 1'[RrJ$Q
J.r^"K\
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 em+dQ15
NYoh6AR
。 PE~umY]
G>/Gw90E
分页支持类:
\~]HfDu
ZPieL&uV`
java代码: arR9uxP
<,r|*pkhp~
-_bnGY%,
package com.javaeye.common.util; *ydkx\pT
GESEj%R/b
import java.util.List; 3 %ppvvQ
`u zR!^X
publicclass PaginationSupport { Ua>lf8w<
7hs1S|
publicfinalstaticint PAGESIZE = 30; <QlpIgr
Q M#1XbT
privateint pageSize = PAGESIZE; vdn`PS'#
''{REFjK7
privateList items; 6`>WO_<z
`UC
privateint totalCount; _6b?3[Xz
0]3 ,0s $}
privateint[] indexes = newint[0]; #y<KO`Es
Vq'\`$_
privateint startIndex = 0; T<hS
ne]P -50
public PaginationSupport(List items, int O_zW/#
ewo]-BQS
totalCount){ O%g
Q
setPageSize(PAGESIZE); Yyr
qO^9m
setTotalCount(totalCount); !X[P)/?b0+
setItems(items); -d. i4X3j
setStartIndex(0); +8|9&v`
} (KLhF
Kqz+:E8D
public PaginationSupport(List items, int 4J1_rMfh
3&!v"ms
totalCount, int startIndex){ I7#^'/
setPageSize(PAGESIZE); _P`
^B
setTotalCount(totalCount); nWes,K6T
setItems(items); 6l PuYEmT
setStartIndex(startIndex); 3L CT-rp
} 9sN#l
%Z3B9
public PaginationSupport(List items, int jL7r1pu5
D$AvD7_
totalCount, int pageSize, int startIndex){ aX2N
Qq>s
setPageSize(pageSize); 6)PnzeYW
setTotalCount(totalCount); 0v,fY2$c
setItems(items); :Xs4 C%H;
setStartIndex(startIndex); vGnFX0?h
} FHSFH>
r1Hh @sxn
publicList getItems(){ l;rA}?,.^
return items; I)kc[/^j$
} 0@um
#+N_wIP4
publicvoid setItems(List items){ A>8~deZ9
this.items = items; {;|pcx\L6~
} po(pi|
)vUS). ;S`
publicint getPageSize(){ D~bx'Wr+
return pageSize; |@~_&g
} I4|"Ztw
Eg&:yF}?(
publicvoid setPageSize(int pageSize){ %JH/|mA&|
this.pageSize = pageSize; &8pGq./lr=
} /i dI-
ACy}w?D<
publicint getTotalCount(){ lQiw8qD
return totalCount; C>'G?
} $)nPj_h
=''WA:,=h
publicvoid setTotalCount(int totalCount){ k~Q
5Cs
if(totalCount > 0){ E=CA Wj\
this.totalCount = totalCount; 5}Id[%.x
int count = totalCount / ?0M$p
a0+q^*\d\R
pageSize; `K:n=hpF
if(totalCount % pageSize > 0) $f _C~O
count++; "]uPke@
indexes = newint[count]; :?j=MV
for(int i = 0; i < count; i++){ 5Po:$(
indexes = pageSize * P(FlU]q
4:S]n19nq
i; #t;]s<
} XI|k,Ko<
}else{ IU5T5p
this.totalCount = 0; 0%<
hj
} _3D9>8tzE7
} G[JWG
6Q\|8a
publicint[] getIndexes(){ X(eW+,H
return indexes; N*hV/"joZ
} Woj5
yr
~;]kqYIJ
publicvoid setIndexes(int[] indexes){ k7Qs#L
this.indexes = indexes; RD"-(T
} I |c!:4
S5u$I
publicint getStartIndex(){ 99`w'Nlk
return startIndex; +or<(%o @
} $OdBuJA
j'U1lEZm2
publicvoid setStartIndex(int startIndex){ _tX=xAO9
if(totalCount <= 0) 4ryG_p52l
this.startIndex = 0; m7y[Y
elseif(startIndex >= totalCount) FG[rH]
this.startIndex = indexes A-:k4] {%P
.MG83Si
[indexes.length - 1]; ~tt\^:\3~S
elseif(startIndex < 0) * 30K}&T
this.startIndex = 0; HUD0
@HQI
else{ MTCfs~}m
this.startIndex = indexes te2vv]W1
l*z%Jw
[startIndex / pageSize]; .l_Nf9=
} @L~erg>8=
} {icTfPR4E
OqIXFX"
publicint getNextIndex(){ [
5}Q
int nextIndex = getStartIndex() +
19]19_-
3.?be.cq
pageSize; ws5Ue4g|
if(nextIndex >= totalCount) cZ?$_;=
return getStartIndex(); YmaS,Q-
else H}5WglV.
return nextIndex; P'OvwA
} =xIZJ8e
jw=PeT|
publicint getPreviousIndex(){ K2yNIq_
int previousIndex = getStartIndex() - Y2QX<
J??AU0vh
pageSize; [ ,Go*r
if(previousIndex < 0) |mQ Fi\
return0; =?.oH|&\h
else iBAP,cR?`
return previousIndex; i cTpx#|=
} N$]er'`
YPI)^ }
} |A'I!Jm
$xZ ~bE9
B ??07j
)xyjQ|b
抽象业务类 r)'vn[A
java代码: 1Y'4 g3T
D;V[9E=g/
<Pt?N2]A|
/** b^d{$eoH?|
* Created on 2005-7-12 H/*ol^X7
*/ E^F<"mL*
package com.javaeye.common.business; WsV"`ij#
+n;nvf}(
import java.io.Serializable; $q@d.Z>;
import java.util.List; Y\-xX:n.\
zW%Em81Wd
import org.hibernate.Criteria; TsaQR2J@
import org.hibernate.HibernateException; mg'q-G`\<
import org.hibernate.Session; ~#*C,4m
import org.hibernate.criterion.DetachedCriteria;
'/.Dxib
import org.hibernate.criterion.Projections; o2ggHZe/=@
import ^b+>r
R}=5:)%w
org.springframework.orm.hibernate3.HibernateCallback; DQXUh#t\(]
import ResU5Ce~
+Ua|0>?
org.springframework.orm.hibernate3.support.HibernateDaoS sg
$db62>
U8Y%rFh1
upport; %vJHr!x
/IUu-/ D
import com.javaeye.common.util.PaginationSupport; V|MGG
+H2Jhgi
public abstract class AbstractManager extends CjQO5
yXR1NYg
HibernateDaoSupport { K?^;|m-
crM5&L9zF
privateboolean cacheQueries = false; P9cx&Hk9
,@ 8+%KqG
privateString queryCacheRegion; AatSN@,~z
YO7U}6wBt
publicvoid setCacheQueries(boolean ii)#(b:V
xPm. TPj
cacheQueries){ !wy _3a
this.cacheQueries = cacheQueries; V,&%[H [
} "Lbsq\W>
6 Xvpk1
publicvoid setQueryCacheRegion(String X8|H5Y:
K|P0nJT
queryCacheRegion){ ]ZY2\'
this.queryCacheRegion = t}q
e_c
2Xt4Rqk $
queryCacheRegion; v/`D0g-uX)
} #aP#r4$
JmI%7bH@
publicvoid save(finalObject entity){ ]" 'yf;g
getHibernateTemplate().save(entity); &BVHQ7[
} _\WR3Q!V
DB' 0
publicvoid persist(finalObject entity){ )0"Q
h
getHibernateTemplate().save(entity); m!V,W*RNr
} nh} Xu~#_
;.>*O
oe&
publicvoid update(finalObject entity){ PF{uaKWk
getHibernateTemplate().update(entity); }%< ?]
} ]EiM~n
gQ+]N*.
publicvoid delete(finalObject entity){ E'QAsU8pP
getHibernateTemplate().delete(entity); :R;w<Tbz"
} %rW}x[M%w?
O =Z}DGa+
publicObject load(finalClass entity, w 3t,S3!
mxv?PP
finalSerializable id){ 3<xE_ \DR
return getHibernateTemplate().load ?JrUZXY
noZbsI4
(entity, id); Y 6a`{'
} wLV,E,gM
EmNVQ1w
publicObject get(finalClass entity, NQdwj>_a
C;BO6$*_e
finalSerializable id){ k6tCfq;
return getHibernateTemplate().get Vk6c^/v
+:KZEFY?<
(entity, id); pzF_g-B
} aHhLz>H'
'}OdF*L
publicList findAll(finalClass entity){
NFT:$>83`
return getHibernateTemplate().find("from 6{2y$'m8
N*IroT3
" + entity.getName()); uo:RNokjJ
} j+jC
J<
lu#a.41
publicList findByNamedQuery(finalString RD`|Z~:q:K
^ D0"m>3r
namedQuery){ ql?w6qFs]
return getHibernateTemplate {cdICWy(F3
_}{KS, f]0
().findByNamedQuery(namedQuery); s< tG
} Ws2q/[\oz
d6i}xnmC
publicList findByNamedQuery(finalString query, [@K'}\U^+
[v1$Lp
finalObject parameter){ +)c<s3OCE
return getHibernateTemplate vn.5X
OTy!Q,0$.
().findByNamedQuery(query, parameter); F8%^Ed~@
} A}(xH`A
rJ/HIda
publicList findByNamedQuery(finalString query, Ar%*NxX
Au2^ T1F
finalObject[] parameters){ `xM*cJTZ
return getHibernateTemplate 1d<?K7%^
)!(gS,
().findByNamedQuery(query, parameters); XfcYcN
} ~<1s[Hu
bdrE2m
publicList find(finalString query){ e N`+ r
return getHibernateTemplate().find 8GkWo8rPk
Sct
(query); lBP?7`U
} ZK4V-?/[6
0A}XhX
publicList find(finalString query, finalObject a" s2N%{
SU%O \4Ty
parameter){ 5c5!\g~'
return getHibernateTemplate().find bB@=J~l4
Rk9n,"xpv
(query, parameter); f@sC~A. 9\
}
s(_z1
IB|!51H
public PaginationSupport findPageByCriteria w&@tP^`
%)i&|AV"
(final DetachedCriteria detachedCriteria){ ,u@:(G
return findPageByCriteria W~H`{x%Av>
{GtX:v#
(detachedCriteria, PaginationSupport.PAGESIZE, 0); &zYQH@
} EG4~[5[YgI
t|>P9lX@
public PaginationSupport findPageByCriteria )
`{jPK*`
39^+;Mev
(final DetachedCriteria detachedCriteria, finalint jJ"(O-<)D
e# Y{YtE
startIndex){ m
70r'b]
return findPageByCriteria 6O?zi|J[:
p#c41_?'e
(detachedCriteria, PaginationSupport.PAGESIZE, }^I36$\
)4fQ~)
startIndex); ~_BjcY
} koB'Zp/FaY
5[g&0
public PaginationSupport findPageByCriteria +M.BMS2A<l
Jd `Qa+
(final DetachedCriteria detachedCriteria, finalint 7j|CWurvq
bD)"Jy
pageSize, S/Ic=
finalint startIndex){ ;u`8pF!_eE
return(PaginationSupport) #^9bBF/
Ot.v%D`e 5
getHibernateTemplate().execute(new HibernateCallback(){ V+D <626o
publicObject doInHibernate y?cN
z,ryY'ua/I
(Session session)throws HibernateException { UvMkL
Criteria criteria = [qY yr
_{): w~zi
detachedCriteria.getExecutableCriteria(session); +DQUL|\
int totalCount = G>?kskm
4'3;{k$z
((Integer) criteria.setProjection(Projections.rowCount d@^%fVhG
U6|T<bsOl
()).uniqueResult()).intValue(); 3AENY@*
criteria.setProjection M8:i ]
IAbQgBvUD
(null); NHUJ:j@
List items = W3ms8=z
K:9AP{+
criteria.setFirstResult(startIndex).setMaxResults W4.w
wIAH,3!
(pageSize).list(); 8wO4;
PaginationSupport ps = 34CcZEQQ
bD/ZKvg
new PaginationSupport(items, totalCount, pageSize, o6w8Y/VPu
"N'W~XPG
startIndex); 9:g]DIL
return ps; 9%21Q>Y?b
} mc`Z;D/mt
}, true); =!DX,S7
} wWx{#!W
k:V9_EI=
public List findAllByCriteria(final =mX26l`B
sk07|9nU
DetachedCriteria detachedCriteria){ ]jI<Js*F
return(List) getHibernateTemplate og8hc~:ro
Y|wjt\M
().execute(new HibernateCallback(){ ^B%ki
publicObject doInHibernate D=%1?8K
-B/'ArOo]
(Session session)throws HibernateException { w*~s&7c2B
Criteria criteria = |RD)pvVM
"uL~D5!f
detachedCriteria.getExecutableCriteria(session); vP#*if[V5
return criteria.list(); wjH1Ombt
} zp:QcL"
}, true); _UZPQ[
} hP'4PLK
6~jAh@-
public int getCountByCriteria(final a-S
tOO5s
dg~lz8 0
DetachedCriteria detachedCriteria){ 8PVjNS/
Integer count = (Integer) qAd=i0{N
y]PuY\+
getHibernateTemplate().execute(new HibernateCallback(){ 21Dc.t{
publicObject doInHibernate >r\GB#\5
xR
kw+
(Session session)throws HibernateException { J2
)h":2
Criteria criteria = \6MM7x(U3
-
7T`/6
detachedCriteria.getExecutableCriteria(session); smQl^
6a
return uD?G\"L
i
1anh@T.
criteria.setProjection(Projections.rowCount uh.;Jj;
5oCg&aT
()).uniqueResult(); ?Be}{Qqlg
} {irc~||4
}, true); k{vbi-^6rf
return count.intValue(); (y6}xOa(
} /
yBrlf
} :2M&C+f[
%GY'pQz
z k}AGw
7$g$p&,VX
K, !
V _
XKws_
用户在web层构造查询条件detachedCriteria,和可选的 "9c=kqkX
[mjie1j/<
startIndex,调用业务bean的相应findByCriteria方法,返回一个 pZ\7!rON
<B0f
PaginationSupport的实例ps。 #O;JV}y
(57!{[J
ps.getItems()得到已分页好的结果集 ?$)5NQB%
ps.getIndexes()得到分页索引的数组 y2jw3R
ps.getTotalCount()得到总结果数 %c\kLSe
ps.getStartIndex()当前分页索引 ihwJBN>(
ps.getNextIndex()下一页索引 3Ji$igL
ps.getPreviousIndex()上一页索引 dTK0lgkUE
QM3DB
p$|7T31 *
t>?tWSNf
#6ePwd
%EVgS F!r
<nqv)g"u0
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 EV{Ys}3M
Q*%}w_D6f
,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 b=/'cQ
aif;h!
?y
一下代码重构了。 #L+:MA7H
UWKgf? _
我把原本我的做法也提供出来供大家讨论吧: Pb8@owG8
KsOWTq"uj
首先,为了实现分页查询,我封装了一个Page类: ;TWLo_
java代码: n8F5z|/
\|{/.R
7LVG0A2>7
/*Created on 2005-4-14*/ Px=@Tw N,
package org.flyware.util.page; ;50&s .gZ
Is7BJf
/** ]1<GZ`
* @author Joa 3*=0`}jMJ
* z.SC^/\o|
*/ b@;Wh-{d
publicclass Page { (n*:LS=0
,.W7Z~z
/** imply if the page has previous page */ PY^#hC5:
privateboolean hasPrePage; P$z_A8}
|M?vFF]TN
/** imply if the page has next page */ /gZyl|kdy
privateboolean hasNextPage; =otO@22Np
l,4O
/** the number of every page */ a^p#M
privateint everyPage; ^E.L8
O9sEaVX
/** the total page number */ lQ;BI~
privateint totalPage; [Vo5$w
Zj_2>A
/** the number of current page */ 8#7qHT;cx
privateint currentPage; ",$_\l
W}CM;~*L
/** the begin index of the records by the current (jc& Fk
;KlYiu
query */ a]T:wUYG'
privateint beginIndex; C_Ewu*T7
\EySKQ=
Db,"Gl
/** The default constructor */ \_
3>v5k|
public Page(){
}~/b%^
"B_3<RSL
} *5%vU|9b
-&5YRfr!
/** construct the page by everyPage N,Eap KG
* @param everyPage e7RgA1
* */ K oJ=0jM#
public Page(int everyPage){ )XN_|zCk
this.everyPage = everyPage; \Oeo"|
} Ek_5% n
m2j&0z
/** The whole constructor */ ,CfslhO{j
public Page(boolean hasPrePage, boolean hasNextPage, =nhY;pY3u
q!$s<n
}/cReX,so
int everyPage, int totalPage, cS;3,#$
int currentPage, int beginIndex){ 7IX8ck[D
this.hasPrePage = hasPrePage; @+gr/Pul^
this.hasNextPage = hasNextPage; xb,XI/
this.everyPage = everyPage; 'hpOpIsHa
this.totalPage = totalPage; &k:xr,N=
this.currentPage = currentPage; mmTpF]t
?`
this.beginIndex = beginIndex; @J[@Pu O
} F]\
Sk'}&
Z0,jg)sA4
/** H;/do-W[
* @return Xs0)4U
* Returns the beginIndex. >,e^}K}C
*/ l0qaTpn
publicint getBeginIndex(){ IO\l8G
return beginIndex; A)f-r
} UA>=#
$
Bs "D<r&ro
/** 5\Q Tm;
* @param beginIndex >q"dLZ
* The beginIndex to set. daE.y_9y
*/ Ykxk`SJ
publicvoid setBeginIndex(int beginIndex){
Aa
~W,
this.beginIndex = beginIndex; &dyQ6i$],
} g)Lf^
xl&@g)Jj
/** #l=yD]tPU
* @return W/Dd7G#IC
* Returns the currentPage. /<rvaR
*/ e?>
publicint getCurrentPage(){ nLN0zfhE#
return currentPage; OoB|Eh|),
} ~; 9HGtg
s<I)THC
/** PLCm\Oh$l
* @param currentPage tFmB`*!%
* The currentPage to set. TRhM xH
*/ IZZAR
publicvoid setCurrentPage(int currentPage){ )|~K&qn`
this.currentPage = currentPage; B2;P%B
} htBA.eQ
7^eyO&4z
/** Od!)MQ*,
* @return DbMVbgz<e
* Returns the everyPage. y``\^F
*/ & NYaKu,}
publicint getEveryPage(){ ha
:l-<a
return everyPage; x3+
-wv
} };Q}C0E
odhcD;^X1
/** lc,k-}n
* @param everyPage |Z:yd}d
* The everyPage to set. dxeiN#(XT
*/ &g:( I
publicvoid setEveryPage(int everyPage){ g}_2T\$k
this.everyPage = everyPage; VVJ0?G
(?
} R"cQyG4
9Yt|Wj
/** ,rB(WKU
* @return 4C;;V m4~
* Returns the hasNextPage. 6z\!lOVjb
*/ $kUB%\`
publicboolean getHasNextPage(){ Rw+r1vW:A
return hasNextPage; +hRy{Ps/
} LUQ.=:mBR
g QBS#NY
/** `l|Oj$
* @param hasNextPage =xk>yw!O)
* The hasNextPage to set. a*p|Ij
*/ PzJ(Q
publicvoid setHasNextPage(boolean hasNextPage){ 8m0*89HEu
this.hasNextPage = hasNextPage; /\1'.GR
} ]
(e ,J
6ALjM-t=V
/** By1Tum+I1
* @return @`[e1KQ
* Returns the hasPrePage. ^Gk)aX
*/ )@!fLAT
publicboolean getHasPrePage(){ ?`+VWa[,e
return hasPrePage; LATizu
} aen%
qc(e3x
/** k|OM?\
* @param hasPrePage gP>pbW_
* The hasPrePage to set. ?s, oH
*/ HzM\<YD
publicvoid setHasPrePage(boolean hasPrePage){ W3~u J(
this.hasPrePage = hasPrePage; `)cI^!
} xoVd[c!
dNR/|
/** b_sasZo
* @return Returns the totalPage. :2j`NyLI.
* DOyO`TJi
*/ ^:/c<(DQD
publicint getTotalPage(){ T.cTL.}
return totalPage;
KTYjC\\G
} qt9jZtx
|mMsU,*gB
/** :?~)P!/xl5
* @param totalPage XW aa`q
* The totalPage to set. UG\2wH_
*/ {aA6b
publicvoid setTotalPage(int totalPage){ igL5nE=n
this.totalPage = totalPage; (-yif&
} ~Bl,_?CBr
0V6, &rTF
} ~AD>@;8fG
@(L}:]{@
ft7M9<#v
-J!n 7
Q~"Lyy8
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 o[wiQ9Tl
\RDqW+,
个PageUtil,负责对Page对象进行构造: el<Gd.p.d
java代码: 1\Bh-tzB
auIW>0?}
[-Z 6QzT
/*Created on 2005-4-14*/ Z*P/ ubV'
package org.flyware.util.page; \1-lda
[Y@}{[q5
import org.apache.commons.logging.Log; m!zvt
import org.apache.commons.logging.LogFactory; Jv
5l
W|{!0w
/** f-^*p
* @author Joa Uf_mwEE
* 7#"y mE
*/ Z}zka<y6K6
publicclass PageUtil { D]d! lMK/
B^M
L}$
privatestaticfinal Log logger = LogFactory.getLog ,h%n5R$:
zxs)o}8icO
(PageUtil.class); `r&Ui%fk;0
~eTp( XG
/** )w}'kih
* Use the origin page to create a new page S&=@Hj-
* @param page ZH=Bm^
* @param totalRecords zI"&g]TV5
* @return (j:[<U
*/ P\[K)N/ 1
publicstatic Page createPage(Page page, int gzK/ l:
rx]Q,;"
totalRecords){ .@r{Tq,%q8
return createPage(page.getEveryPage(), H[g i`{c
EQ"_kJ>81Y
page.getCurrentPage(), totalRecords); )2Q0NbDn
} #WUN=u
8>|4iT
/** 8DD1wK\U~
* the basic page utils not including exception #6y fIvap
{?w*n_T.
handler 9JMf
T]
* @param everyPage *XDe:A
* @param currentPage V[^AV"V
* @param totalRecords 1mh7fZgn
* @return page k,OxGG
*/ \\Zsxya1
publicstatic Page createPage(int everyPage, int U1yspHiZ
ho#<?rh_
currentPage, int totalRecords){ rWJRoGk/
everyPage = getEveryPage(everyPage); yq2AZ@}"
currentPage = getCurrentPage(currentPage); we}5'bS>
int beginIndex = getBeginIndex(everyPage, CyVi{"aF3
hYFi"ck
currentPage); =JTwH>fD
int totalPage = getTotalPage(everyPage, .GYdC'
\'w.<)(GI
totalRecords); w4^$@GtN
boolean hasNextPage = hasNextPage(currentPage, ^eV K.
}f{5-iwD}
totalPage); 4*n1Xu7^x
boolean hasPrePage = hasPrePage(currentPage); B'B0 e`
~y 2joStx
returnnew Page(hasPrePage, hasNextPage, vPZ0?r_5W
everyPage, totalPage, 7k#>$sY+
currentPage, ;$*tn"- ?~
KB\ri&bF
beginIndex); _=[pW2p
} E^w0X,0XlE
P$O@G$n
privatestaticint getEveryPage(int everyPage){ =L"I[
return everyPage == 0 ? 10 : everyPage; e=tM=i"
} Z0~,cO8~
ev7A;;
privatestaticint getCurrentPage(int currentPage){ H11@ DQ6
return currentPage == 0 ? 1 : currentPage; fA V.Mj-
} VK%ExMSqEh
PJKxh%J
privatestaticint getBeginIndex(int everyPage, int {poTA+i
m,4'@jg0
currentPage){ uW(Ngcpr
return(currentPage - 1) * everyPage; C3<_0eI
} w(Mi?
6!U~dt#a
privatestaticint getTotalPage(int everyPage, int E_z,%aD[
~2NTXp
totalRecords){ 8M['-
int totalPage = 0; !*wd
d8
m KKa0"
if(totalRecords % everyPage == 0) \u/=?b
totalPage = totalRecords / everyPage; N>j*{]OY+{
else <qoPBm])
totalPage = totalRecords / everyPage + 1 ; c!$~_?]
1JGww]JZo
return totalPage; {v3@g[:|
} MzW!iG
~vZ1.y4
privatestaticboolean hasPrePage(int currentPage){ TYxi&;w
return currentPage == 1 ? false : true; Pl|*+g
} e7Sg-NWV
'F1<m^
privatestaticboolean hasNextPage(int currentPage, Hc0V4NHCaL
x;7p75Wm
int totalPage){ <Lle1=qQ
return currentPage == totalPage || totalPage == @a]`C
$6
"+&@iL
0 ? false : true; _=qk.| p/
} m}m|(;T
{X\FS
;UQ&yj%x
} {mHxlG)
T !pHT'J
9\r5&#<(I
=*WfS^O
[}l
1`>
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。 ?zXlLud8
rqM_#[Y?
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 ${UH!n{
k~1{|HxrE
做法如下: - :x6X$=
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Pv$O=N6-
;4vx+> -
的信息,和一个结果集List: ?l
0WuU
java代码: Nu; 9
cl'qw##
0te[i*G
/*Created on 2005-6-13*/ yA<\?Ps
package com.adt.bo; I]~UOl
7YU}-gi
import java.util.List; Eo{js?1G_
1i|5ii*vc
import org.flyware.util.page.Page; U&gl$/4U@
|uA /72
/** B{Lzgw u;
* @author Joa 4=;`\-7!
*/ CakB`q(8
publicclass Result { <*4r6UFR
gn${@y?
private Page page; 3_Re>i
'p,54<e
private List content; `9VRT`e
sGJZG
/** )9rJ]D^B
* The default constructor g^2H(}frc
*/
["Jt2
public Result(){ A@ G%*\UZ
super(); mLeK7?GL
} VSm{]Z!x
UZW)%
/** 14Jkr)N
* The constructor using fields w5Yt mnP
* xNxSgvco,
* @param page Z
uO
7N
* @param content KQrG|<J
*/ !*-|s}e
public Result(Page page, List content){ Jpo(O>\P
this.page = page; NFb<fD[C
this.content = content; WNV}@
} 0a's[>-'A
<3bFt [
/**
qmGLc~M0
* @return Returns the content. ~$ "P\iJ
*/ * @'N/W/8
publicList getContent(){ wEb10t,
return content; $)M5@KT
} 7brC@+ZD
b,RQ" {
/** P?YcZAJT*
* @return Returns the page. IaR D"oCH
*/ :.fm LL
public Page getPage(){ xAAwH@ +
return page; "?{=|%mf
} .|3&lb6
q!8aYw+c
/** Fpy-?U
* @param content w:[\G%yQ
* The content to set. FO
xZkU\e=
*/ +Rd;>s*.Y
public void setContent(List content){ -f8iq[F5
this.content = content; V5HK6- T
} g,5Tr_
;Z{jol
/** C.9l${QU
* @param page rW0-XLbL5H
* The page to set. |jTRIMj%,_
*/ ~~3 BV,
publicvoid setPage(Page page){ xEqr3(
this.page = page; :PDyc(s{
} xIa8Ac
} Z(a,$__
qv$m5CJvK
]F*fQNcjy
I=9sTR)
w|8T6W|w
2. 编写业务逻辑接口,并实现它(UserManager, jB%aHUF;
-1tiy.^$F
UserManagerImpl) rl](0"Y0
t
java代码: p`06%"#
._US8
+I r
/*Created on 2005-7-15*/ YS+|n%?
package com.adt.service; zqa7!ky
ppK`7J>Z
import net.sf.hibernate.HibernateException; v<tr1cUT
jk fc=O6^
import org.flyware.util.page.Page; ]?a i
4b:q84
import com.adt.bo.Result; e4(E!;Z!QF
ZA6)@Mn
/** 2N[/Cc2Tg/
* @author Joa q2~@z-q)b
*/ Alpk5o5B
publicinterface UserManager { ($r-&]y
BDz7$k]
public Result listUser(Page page)throws vKmV<*K
%oHK=],|1
HibernateException; `0Bk@B[>
zM2_z
} Q?]-/v
6h:2,h
pE
Av_JcH
7HM%Cd
7FGi+
java代码: .I
nDyKt
_%:$sAj
|58xR.S'g
/*Created on 2005-7-15*/ 20A`]-D
package com.adt.service.impl; oZ,_ G,b^
sA!$}W
import java.util.List; 2c1L[]h'
=`Lci1#pu}
import net.sf.hibernate.HibernateException; u+5MrS[
TNkvdE-S
import org.flyware.util.page.Page; fuF!3Q
import org.flyware.util.page.PageUtil; 1j?+rs+o-
_|I`A6`=
import com.adt.bo.Result; /l1OC(hm
import com.adt.dao.UserDAO; VHqHG`}:
import com.adt.exception.ObjectNotFoundException; GYwU3`{
import com.adt.service.UserManager; ="J *v>
YML]pNB
/** a(oa?OdJ
* @author Joa u4vyj#V
*/ 1V:I}~\
publicclass UserManagerImpl implements UserManager { iqr/MB,W
omzG/)M:O
private UserDAO userDAO; Z|$M 9E
x
?24oO
/** }ej>uZVe<
* @param userDAO The userDAO to set. &hu>yH>j
*/ ~kFL[Asnaf
publicvoid setUserDAO(UserDAO userDAO){ F_F02:t
this.userDAO = userDAO; !8*lU2
} wGg_ vAn
FS^~e-A
/* (non-Javadoc) Ra/Pk G-7
* @see com.adt.service.UserManager#listUser VDTt}J 8
7]H<ou
(org.flyware.util.page.Page) cB=ExD.Q
*/ b|oT!s
public Result listUser(Page page)throws ,=V9?
<NXJ&xs-+
HibernateException, ObjectNotFoundException { XR|U6bf]
int totalRecords = userDAO.getUserCount(); Gy)2
if(totalRecords == 0) 3t9Weo)
throw new ObjectNotFoundException <\ EJ:
`Vl9/IEk
("userNotExist"); YJu~iQ`i
page = PageUtil.createPage(page, totalRecords); Ake@krh>$
List users = userDAO.getUserByPage(page); SNtk1pG>
returnnew Result(page, users); <NWq03:&
} ez<V
2"6bz^>}
} g5:?O,?
'S%H"W\
5.d[C/pRw
sOVU>tb\'
GRh430V[
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 Z0%:j\W4c
JIPBJ
询,接下来编写UserDAO的代码: qWM+!f
3. UserDAO 和 UserDAOImpl: 5Mz:$5Tm
java代码: 1]69S(
Kf1NMin7
_;M3=MTM9
/*Created on 2005-7-15*/ {B-*w%}HU
package com.adt.dao; ,&.$r/x|?
8qL.L(=\/
import java.util.List; &-Ylj
QQJf;p7
import org.flyware.util.page.Page; -}3nIk<N
Vh{(*p
import net.sf.hibernate.HibernateException; }i{A4f`
TJCE6QG
/** l];/,J^
* @author Joa 6n^@Ps
*/ $*;`$5.x^
publicinterface UserDAO extends BaseDAO { "+E\os72|
P ; h8
publicList getUserByName(String name)throws ?N^1v&Q
?4^ 0xGyE
HibernateException; +z4E:v
BP}@E$
publicint getUserCount()throws HibernateException; h4#'@%
1mD)G55Ep
publicList getUserByPage(Page page)throws #a9O3C/MP
5;+KMM:zb
HibernateException; _b$ yohQ
M|NQoQ8q
} XBoq/kbw!
|az2vD6P
te4=
5|5p -B
eR0$CTSw
java代码: flT6y-d
.+,U9e:%
"9 f+F
/*Created on 2005-7-15*/ 6$[7hlE
package com.adt.dao.impl; U*b7 Pxq;
zz
/4 ()u
import java.util.List; 3)yL#hXg)
vA}_x7}n(
import org.flyware.util.page.Page; l0C`teO
mRa\ wEg%
import net.sf.hibernate.HibernateException; 0<O()NMv
import net.sf.hibernate.Query; )2_[Ww|.
c]zFZJ6M
import com.adt.dao.UserDAO; 3{fg3?
A,BYi$
/** z0OxJ e
* @author Joa tv26eK
38
*/ ,J8n}7aI
public class UserDAOImpl extends BaseDAOHibernateImpl T7%!JBg@
L$BV`JWPw
implements UserDAO { "Kdn`zN{
G;$;$gM
/* (non-Javadoc) 'qvj[lpGr
* @see com.adt.dao.UserDAO#getUserByName K|YB)y
_ OC@J*4.
(java.lang.String) BlQX$s]
*/ ^Kg n:l
publicList getUserByName(String name)throws fjOq@thD
}opw_h+/F
HibernateException { Ulx]4;uzf
String querySentence = "FROM user in class fbU3-L?
lLDZ#'&An
com.adt.po.User WHERE user.name=:name"; [}]yJ+)
Query query = getSession().createQuery rlD!%gG2x
*= ?|n
(querySentence); 15hqoo9!
query.setParameter("name", name); Fj(GyPFG
return query.list(); /0 4US5En
} P:t .Nr"
#-@uLc
/* (non-Javadoc) .p, VZ9
* @see com.adt.dao.UserDAO#getUserCount() 6y~F'/ww
*/ Rq%Kw> {&
publicint getUserCount()throws HibernateException { Q2D!Agq=D
int count = 0; N-]/MB8
String querySentence = "SELECT count(*) FROM W"^ =RY
5|nc^
12
user in class com.adt.po.User"; <l$ d>,
Query query = getSession().createQuery X.#)CB0c1Q
T4HJy|
(querySentence); t:5-Ro
count = ((Integer)query.iterate().next #,u|*O:
z V\+za,
()).intValue(); t2s/zxt
return count; 10i$ b<O
} "J`&"_CyZ
+l/v`=C
/* (non-Javadoc) {BT/P!
* @see com.adt.dao.UserDAO#getUserByPage 0=#>w_B
S.)Jp-&K
(org.flyware.util.page.Page) }&t>j[
*/ !7
dct#4
publicList getUserByPage(Page page)throws &8z<~q
d.^g#&h
HibernateException { (XQuRL<X
String querySentence = "FROM user in class 6:O<k2=2
Ca
PHF@6WN
com.adt.po.User"; weSq|f
Query query = getSession().createQuery kB> ~Tb0
IF|6iKCE
(querySentence); yjg&/6
query.setFirstResult(page.getBeginIndex()) b1KtSRLV
.setMaxResults(page.getEveryPage()); *Bq}.Yn
return query.list(); 52dD(
} ylKK!vRHT
Ch_rV+
} j
0pI
[YfoQ1
N);w~)MYh
/N"3kK,N
UnF8#~
至此,一个完整的分页程序完成。前台的只需要调用 "(^XZAU#W
hd(FOKOP
userManager.listUser(page)即可得到一个Page对象和结果集对象 `x#Ud)g
@)?]u
U"L
的综合体,而传入的参数page对象则可以由前台传入,如果用 ?
T6K]~g
OegeZV
webwork,甚至可以直接在配置文件中指定。 AQlB_@ b
&(rWl`eTY`
下面给出一个webwork调用示例: i(^U<DW$
java代码: {P]C>
W(`QbNJ
#_@cI(P
/*Created on 2005-6-17*/ S3E,0%yo+)
package com.adt.action.user; xi=ApwNj
pn
gto
import java.util.List; TZAd{EZa
G
@..?>
import org.apache.commons.logging.Log; t?W}=%M[
import org.apache.commons.logging.LogFactory; {`QHg O
import org.flyware.util.page.Page; '6#G$
(~=.[Y
import com.adt.bo.Result; En?V\|,
import com.adt.service.UserService; //U1mDFT
import com.opensymphony.xwork.Action; z%%O-1
W]9*dabem
/** ff\~`n~WZ
* @author Joa hm`=wceK
*/ 4VWk/HK-!
publicclass ListUser implementsAction{ LH8jT
RZm%4_p4s
privatestaticfinal Log logger = LogFactory.getLog [@vz0!@s5
NQk aW)
(ListUser.class); -{cHp
6Dlm.~G
private UserService userService; xzOa9w/
=|S%Rzsk
private Page page; 3/kT'r
IOcQI:4.`
privateList users; 8Xotly
QF#w$%7
/* 3@>F-N
* (non-Javadoc) `6D?te
* vk&
gR
* @see com.opensymphony.xwork.Action#execute() {LO Pm1K8Y
*/ r9i?H
publicString execute()throwsException{ %lF*g
Result result = userService.listUser(page); H5=kDkb
page = result.getPage(); 5i!Q55Yv=,
users = result.getContent(); 3!"N;Q"
return SUCCESS; )/H;5 cn
} >='/%Ad
$YL9 vJV
/** Gk,Bx1y
* @return Returns the page. E.oJ[;
*/ GXtMX ha,
public Page getPage(){ LL^KZ-
return page; K4c:k;
V
} Jz}nV1G(jz
#DTKz]i?
/** t]yxLl\
* @return Returns the users. };/QK*
*/ Z2% HQL2
publicList getUsers(){ L"bOc'GfQ
return users; liKlc]oM
} eUyF<j
^SdF\uk{?6
/** -8TJ:#|N
* @param page #~*v##^vFH
* The page to set. )h{&O
,s
*/ )`\hK
publicvoid setPage(Page page){ xY^sC56Z
this.page = page; 25Dl4<-Z
} ~MC|
m&.LJ*uM\K
/** CRb8WD6.
* @param users :xh{SsW@
* The users to set. {Su?*M2y
*/ i"2OsGT
publicvoid setUsers(List users){ "TV'}HH
this.users = users; 4CNrIF@
} D*XrK0#Z`
QQ*sjK.(
/** o.+;]i}D
* @param userService Dp@XAyiA[
* The userService to set. ~ZHjP_5Q
*/ PobX;Z
publicvoid setUserService(UserService userService){ gq+SM
i=
this.userService = userService; 1K72}Gj)ZL
} '0<d9OlJ}
} t&r.Kf9Z\
"HMEoZ
{keZ_2
1|bXIY.J*
+#}GmUwPG$
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, d>NGCe
7FB?t<x
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 B VBn.ut
]P4WfV
d
么只需要: R=D]:u<P
java代码: Njq}M/{U
o-,."|6
vwCQvt
<?xml version="1.0"?> rPV
Q#iB
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork (I[_}l
615Ya<3f8
1.0//EN" "http://www.opensymphony.com/xwork/xwork- ,6)N.
H?$dnwR
1.0.dtd"> xEb>6+-F@
#8$?#
dT
<xwork> Y"Cf84E
ZlT }cA/n
<package name="user" extends="webwork- pu-HEv}]a|
eV;r /4
interceptors"> th?+TNb^
9^gYy&+>6]
<!-- The default interceptor stack name E
C?}iP
BZq#OAp
--> '\:4Ijp<"
<default-interceptor-ref }0'=}BE
X+hHE kJ
name="myDefaultWebStack"/> K9!HW&?<|
}LHYcNw^z
<action name="listUser" ^&zCPUH
=|t-0'RsN
class="com.adt.action.user.ListUser"> Ayz*2N`%
<param > I2rj2M#
S|85g1}t
name="page.everyPage">10</param> *t@A-Sn
<result #mxOwvJ
!Sc"V.o@!
name="success">/user/user_list.jsp</result> L^J4wYFTO
</action> ]e>qvSuYh
6g(;2gY
</package> bLqy7S9x
agIqca;
</xwork> DUp`zW;B
_&gi4)q
z7K{ ,y
Q$%apL
C$[d~1t6
d&AG~,&d|
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 Nx}nOm
i8iT}^
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。 x|H`%Z
bA;OphO(
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 a:FU- ^B4~
O-?rFNavxp
bI):-2&s}
qmS9*me
{
mF4W4~"
我写的一个用于分页的类,用了泛型了,hoho 5ggyk0
qu=~\t1[6
java代码: 7?P'f3)fG
]so/AdT9hA
m`yvZ4K!
package com.intokr.util; I
_nQTWcm
"1O_h6C
import java.util.List; n,N->t$i
#bOv}1,s
/** M/3;-g
* 用于分页的类<br> MxTJgY
* 可以用于传递查询的结果也可以用于传送查询的参数<br> ]OAU&t{
* Z@~gN5@,M
* @version 0.01 Kb~nC6yJc
* @author cheng bnxp[Qk|5
*/ 1p&.\ ^
public class Paginator<E> { 5100fX}
privateint count = 0; // 总记录数 {K^5q{u
privateint p = 1; // 页编号 bz*@[NQ
privateint num = 20; // 每页的记录数 'L /)9.29
privateList<E> results = null; // 结果 U2Ve @.
Vt`4u5HG
/** '+Dsmoy
* 结果总数 xIdb9hm<
*/ lhUGo =
publicint getCount(){ E=NjWO
return count; Gu;40)gm
} U/>I! 7oe
7HkO:/
publicvoid setCount(int count){ TWP@\ BQ
this.count = count; &RR;'wLoQT
} WQ|Ufl;
$^x=i;>aK.
/** \!ZA#7
* 本结果所在的页码,从1开始 /b+~BvTh
* "4b{YWv
* @return Returns the pageNo. 0h-NT\m
*/ gtKih
publicint getP(){ D*l(p5[
return p; y?sz&*:
} ak 7%
\XDiw~0
/** \f,<\mJ#
* if(p<=0) p=1 }8'_M/u\
* LkbD='\=
* @param p e=Ox~2S
*/ $tlBI:ay1
publicvoid setP(int p){ V&zeC/xSq
if(p <= 0) oodA&0{)d
p = 1; 6
AO(A
*
this.p = p; 2;)IBvK
} /xn|d#4
2> a&m>
/** @ &jR^`Y.
* 每页记录数量 \kE0h\
*/ ys=2!P-[#
publicint getNum(){ 175e:\Tw
return num; '4,?YcZ?S
} `zoHgn7B9q
c |0p'EQ
/** !t% 1G.
* if(num<1) num=1 P|NGAd
*/ 5BrN
uR$
publicvoid setNum(int num){ V_i&@<J
if(num < 1) `E~"T0RX
num = 1; Y3@+aA
this.num = num; ~/^fdGr
} PYQ0&;z
lDS y$
/** LWr YKi
* 获得总页数 ("`"?G
*/ +|C@B`h
publicint getPageNum(){ :6n4i$
return(count - 1) / num + 1; VgPlIIHh5
} %[XP}L$
&XNt/bK-?
/** =CzGI|pb
* 获得本页的开始编号,为 (p-1)*num+1 |=5zI6pT
*/ l!1_~!{y
publicint getStart(){ lz^Vi!|p
return(p - 1) * num + 1; uh\G6s!4/
} 5K
Ij}VN
(N/u@ M
/** =Ti!9_~
* @return Returns the results. +S+!:IB
*/
II'.vp
publicList<E> getResults(){ 65Z}Hf
return results; gX"
} 5Q"yn2b4
bI.hG32
public void setResults(List<E> results){ nw+t!C
this.results = results; Sr+hB>{
} 'c~SE>
vhMoCLb
public String toString(){ q,K|1+jn
StringBuilder buff = new StringBuilder G
1{m" 1M
wn"\@Qv G
(); 4EYD5
buff.append("{"); fAh|43Y*a
buff.append("count:").append(count); olv&K(-ccI
buff.append(",p:").append(p); iKq_s5|sW
buff.append(",nump:").append(num); (ot,CpI(I
buff.append(",results:").append "%K'~"S#Q,
H~*N:$C
(results); Az8b_:=
buff.append("}"); K0>;4E>B
return buff.toString(); gpq ,rOIK
} o^@#pU <
KXZG42w
} LYAGpcG
<hzHrx'o{
Cuylozj$&