Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 4grV2xtX
v$` 3}<3-
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 (M;d*gNr
5<X"+`=9
据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 >l}v
_k*~B
L7- JK3/E
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 %D-!<)z
N]8/l:@
。 Lm$KR!z
^Zpz@T>m
分页支持类: $lB!Q8a$
mr[ 1F]G
java代码: VB^1wm
4Tuh]5
k'.cl^6Z8
package com.javaeye.common.util; 'n{=`e(}cI
e8SAjl"}
import java.util.List; Q$Qr)mcC
:V"e+I
publicclass PaginationSupport { xz:
xNY&*jI
publicfinalstaticint PAGESIZE = 30; |1kA6/
hRKJKQ@7
privateint pageSize = PAGESIZE; -=
c&K&
_7v4S/V
privateList items; R(>
oyxA[F
5 3+C;]J
privateint totalCount; ixy:S1pI
o7tlkSZ
privateint[] indexes = newint[0]; ,*Wh{)
m k~F@
privateint startIndex = 0; 0I)eYksh
M G&vduu
public PaginationSupport(List items, int iMM9a;G+
j~rW
2(
totalCount){ Q&$2F:4f&
setPageSize(PAGESIZE); Y}}1]}VIK
setTotalCount(totalCount); ER`;0#3[9u
setItems(items); H(?+-72KX
setStartIndex(0); (eT9N_W
} 5!i\S[:
=f=>buD
public PaginationSupport(List items, int {JQV~rfh`
m,5m'9dj
totalCount, int startIndex){ abVEi[nP
setPageSize(PAGESIZE); X.e4pLwGK
setTotalCount(totalCount); abe5 As r
setItems(items); ME*zMLoF+
setStartIndex(startIndex); cor!S a>
} 2e,cE6r
|em_l$oGc
public PaginationSupport(List items, int BN`tiPNEp
Nc EPPl0I
totalCount, int pageSize, int startIndex){ zcV~)go6
setPageSize(pageSize); 7Or?$
setTotalCount(totalCount); 3cqc<
setItems(items); M%13b$i~f
setStartIndex(startIndex); J"eE9FLM
} RXO}mu]Iu
M&(0n?R"R
publicList getItems(){ 7
A{R0@
return items; P` CQ)o
} 9$sx+=(
[2!?pVI
publicvoid setItems(List items){ )\e0L/K@
this.items = items; O2Y1D`&5
} 9j5k=IXg#a
Y>i
Qp/k:
publicint getPageSize(){ 1OFrxSg
return pageSize; z4[8*}
} /GP:W6:6z6
LqQ&4I
publicvoid setPageSize(int pageSize){ V'N]u(^
this.pageSize = pageSize; \ 0F
ey9c
} 3 lKBwjW
CTB
qX
publicint getTotalCount(){ 30cb+)h(
return totalCount; "f!H[F1~
} zM%2h:*+{
bhjJH,%_>
publicvoid setTotalCount(int totalCount){ r*Z p-}
if(totalCount > 0){ pr\OjpvD
this.totalCount = totalCount; 78'3&,+si
int count = totalCount / N,ihQB5
Xj6?,J
pageSize; s=&x%0f%
if(totalCount % pageSize > 0) !M7727
count++; Coe%R(x5
indexes = newint[count]; )k 6z
for(int i = 0; i < count; i++){ r [n vgzv@
indexes = pageSize * O3L:v{Kn
GZiN&}5e
i; K{G\=yJ((
} "V4ru&a
}else{ I(Q3YDdb
this.totalCount = 0; ]EvK.ORy
} F$,i_7Z&6
} ibuoq X`
|HTTTz9R.
publicint[] getIndexes(){ O=}jg0k
return indexes; C/z 0/mk
} KupQtT<
{@67'jL
publicvoid setIndexes(int[] indexes){ PAjH*5IA
this.indexes = indexes; 0e~4(2xK
} Hc-68]T
RZ9chTX/
publicint getStartIndex(){ LyT[
return startIndex; pTcN8E&Unz
} D7,{p2<2T
u`Zj~t
publicvoid setStartIndex(int startIndex){ Z2{G{]EV(
if(totalCount <= 0) G4K3qD#+H
this.startIndex = 0; WaDdZIz4
elseif(startIndex >= totalCount) =(as{,j
this.startIndex = indexes D"s
]dQ$r
68a
[indexes.length - 1]; `yua?n
elseif(startIndex < 0) RATW[(ZA
this.startIndex = 0; uPL|3ACS
else{ 0(az 80
p
this.startIndex = indexes idP2G|Z
5l
/EZ\q
[startIndex / pageSize]; w;DRC5V>
} }Lb[`H,}A
} sG k'G573
uKpWb1(
publicint getNextIndex(){ OR-fC
int nextIndex = getStartIndex() + /U,;]^
\QMRuR.
pageSize; mT#ebeBaf
if(nextIndex >= totalCount) >}!})]Xw9
return getStartIndex(); D"GQlR
else ,wH]|`w
return nextIndex; A}(Q^|6
} \9jvQV/y
uY$BZEuAZ
publicint getPreviousIndex(){ t8z=R6zX
int previousIndex = getStartIndex() - (Q][d+} /
6nHyd<o
pageSize; -@G,Ry-\t
if(previousIndex < 0) S5xum_Dq
return0; !:<n]-U
else P4 dhP-t
return previousIndex; ]^DNzqu=@h
} ~V!gHJ5M
<(dg^;
} L[.RV*sL
r2xIbZ
l]__!X
u+,
抽象业务类 z+qrsT/?L
java代码: qHra9yuSh
EPGp8VGXp~
2:Q2w3Xe
/** @vkO(o
* Created on 2005-7-12 `@Tl7I\
*/ ,7w[r<7
package com.javaeye.common.business; Ld:U~M-
Ny)N
import java.io.Serializable; Ga#5xAI{a
import java.util.List; G[z4 $0f
nEboet-#D0
import org.hibernate.Criteria; $"6O92G(hJ
import org.hibernate.HibernateException; U8R*i7
import org.hibernate.Session; pv ;ZR
import org.hibernate.criterion.DetachedCriteria; ^+'\
u;\
import org.hibernate.criterion.Projections; B@v"giJg r
import ,5HC&@
1wM~),B8
org.springframework.orm.hibernate3.HibernateCallback; E)utrO R
import a+ lGN
I<^&~==
org.springframework.orm.hibernate3.support.HibernateDaoS %cFqD
& 6
O7D61~G]
upport; ;dE'# Kb
;ax%H @o
import com.javaeye.common.util.PaginationSupport; z)U/bjf
Sk|DVV$
public abstract class AbstractManager extends !JWZ}uM6
UbSAyf
HibernateDaoSupport { ftwn<B
,f?+QV\T.
privateboolean cacheQueries = false; f{eMh47 NC
o!>h
Q#h
privateString queryCacheRegion; W"*~1$vf
,"EgYd8-'
publicvoid setCacheQueries(boolean Z@{e\sZ)
d\A!5/LG
cacheQueries){ ),]XN#jp(u
this.cacheQueries = cacheQueries; g|rbkK%SoE
} kKEs >a
9L9+zs3k
publicvoid setQueryCacheRegion(String On4tK\l@
TIre,s)_
queryCacheRegion){ 2u?k;"]V
this.queryCacheRegion = f15f)P
|ww@V<'/#
queryCacheRegion; 1a>TJdoa
} Q%
LQP!Kg
UUaC@Rs2
publicvoid save(finalObject entity){ ud,=O Xq
getHibernateTemplate().save(entity); ~Ddlr9Ej
} Y+0HC2(o
# 8fq6z|JZ
publicvoid persist(finalObject entity){ @Rp#*{
getHibernateTemplate().save(entity); Nr#" 5<W
} 2E*h,Mo
o+I'nFtnI
publicvoid update(finalObject entity){ sxFkpf_h
getHibernateTemplate().update(entity); IFfB3{J
} U+wfq%Fz
$F/Uk;*d!
publicvoid delete(finalObject entity){ yTwtGo&
getHibernateTemplate().delete(entity); $Y9Wzv3Ra
} A-om?$7
?'I pR
publicObject load(finalClass entity, n+9rx]W,
-K*&I!
finalSerializable id){ !au%D?w
return getHibernateTemplate().load N497"H</
I`
+%ab
(entity, id); qGrUS_~q*
} s%l`XW;v
5`H.{4@
publicObject get(finalClass entity, !H/5Ud9
bIP%xl
Vp
finalSerializable id){ $:D-dUr1
return getHibernateTemplate().get rI.CCPY~s
GB\1'
(entity, id); 052ezh_
} 7IUu] Fi
Gbrc!3K2
publicList findAll(finalClass entity){ IP=."w
return getHibernateTemplate().find("from T\b-<Xle
h<I C
d'!
" + entity.getName()); Z/~7N9?m(
} Lx#CFrLQ*
.R5(k'g?
publicList findByNamedQuery(finalString 6h%_\I.Z[[
/_.1f|{B
namedQuery){ ?f'iS#XL
return getHibernateTemplate mX&!/U
vS'l@`Eg]
().findByNamedQuery(namedQuery); t`oH7)nut
} j'M=+
ywj'S7~A
publicList findByNamedQuery(finalString query, \mGok<b4
.qAlPe L:
finalObject parameter){ $G}!eV
6
return getHibernateTemplate d:SLyFD$q
h}SP`
().findByNamedQuery(query, parameter); k^C^.[?
} VS
?n pH
z(g6$Y{
publicList findByNamedQuery(finalString query, ~H1ZQ[
nXFPoR)T
finalObject[] parameters){ (`me}8
return getHibernateTemplate xq-TT2}<L
pf[m"t6G~
().findByNamedQuery(query, parameters); S&Szc0-|k
} Bt[Wh@
!Un&OAy.!
publicList find(finalString query){ _Z{EO|L
return getHibernateTemplate().find P'Diie
8k|&&3_[?
(query); NL}Q3Vv1.
} }ofx?s}
;VW->ia6
publicList find(finalString query, finalObject ;V)jC
$3c9iVK~_
parameter){ o7=#ye&P
return getHibernateTemplate().find aTU[H~dTU
R?L?6~/q
(query, parameter); ` 5lW
} @:%p#$V
![H{ndH!Q
public PaginationSupport findPageByCriteria %(YU*Tf~
c3]`W7E6L
(final DetachedCriteria detachedCriteria){ yi&6HNb
return findPageByCriteria c]1\88
TkyP_*
(detachedCriteria, PaginationSupport.PAGESIZE, 0); XS oHh-
} 4Mck/i2
t$zeBOI)
public PaginationSupport findPageByCriteria c%x9.s<+1
1];OGJuJ2
(final DetachedCriteria detachedCriteria, finalint /(jG9RM
"HwSW4a]
startIndex){ 5 ^867
return findPageByCriteria "%E<%g
KMll8X
(detachedCriteria, PaginationSupport.PAGESIZE, }|u>b!7_.
vp|'Yy(9z
startIndex); h#JX$9
} up==g
PL|zm5923
public PaginationSupport findPageByCriteria &@ [pJ2
/C\tJs
(final DetachedCriteria detachedCriteria, finalint |9Pi*)E
;6AanwR6
pageSize, =;A>1g$
finalint startIndex){ oo-O>M#5
return(PaginationSupport) KJP}0|[
qLWM,[Og
getHibernateTemplate().execute(new HibernateCallback(){ ec3zoKtV
publicObject doInHibernate J5"d|i
aGbHDo
(Session session)throws HibernateException { !))!!{
Criteria criteria = HnsPXF'8g
K=N8O8R$y
detachedCriteria.getExecutableCriteria(session); %Kzu&*9Hb
int totalCount = Vf#g~IOI
o*sss
((Integer) criteria.setProjection(Projections.rowCount [!ilcHE)
+%!'~
()).uniqueResult()).intValue(); ?"-1QG
criteria.setProjection Ny` =]BA
1EAQ ~S!2
(null); tV"Jh>Z
List items = 1uco{JX<S
*)D$w_06S
criteria.setFirstResult(startIndex).setMaxResults 2|\WaH9P
O<()T6
(pageSize).list(); \&\U&^?
PaginationSupport ps = D5"Xjo*
MN^d28^/
new PaginationSupport(items, totalCount, pageSize, m(KBg'kQ
4Is Wp!`W
startIndex); 9}A\BhtiM
return ps; l8 H8c &
} +%=lu14G
}, true); MREB
} >UnLq:G
]O&\P n0q
public List findAllByCriteria(final \OE,(9T2P.
SQT]'
DetachedCriteria detachedCriteria){ YkF52_^_
return(List) getHibernateTemplate sv)4e)1
vlC$0P
().execute(new HibernateCallback(){ I3;03X<2
publicObject doInHibernate LbUH`0:%t
0iI|eE o
(Session session)throws HibernateException { M3!4,_!~
Criteria criteria = 'l $ViNq;
'37 <+N
detachedCriteria.getExecutableCriteria(session); 'OI(MuSn
return criteria.list(); UK5u"@T
} aNUMF
}, true); h{ T{3
} Vl/fkd,Z
3FG'A[x3O
public int getCountByCriteria(final hdDL92JVg
)(+q~KA}
DetachedCriteria detachedCriteria){ y*e({fio_
Integer count = (Integer) sL],@z8<k
{RN-rF3w
getHibernateTemplate().execute(new HibernateCallback(){ sB0m^Y'
publicObject doInHibernate JH._/I
3}5Ya\x
(Session session)throws HibernateException { }CM#jN?(
Criteria criteria = BVG.ZZR})
dlH&8
detachedCriteria.getExecutableCriteria(session); N{H#j6QW
return Yy0U2N[i
t1ers> h
criteria.setProjection(Projections.rowCount *X
uIA-9
PckAL
()).uniqueResult(); NtNCt;_R7
} d)kOW!5\
}, true); ^B$cfs@*
return count.intValue(); M^{=&
} n(#[[k9&Ic
} 49=L9:
Nz>xilU'
vLpIVNA]]Y
LcTTfb+<
h{:
]'/@~
tuJ{IF
用户在web层构造查询条件detachedCriteria,和可选的 kTA4!654
%wco)2
startIndex,调用业务bean的相应findByCriteria方法,返回一个 ?Xj@Sx
@$1jp4c
PaginationSupport的实例ps。 G^:?)WRG
afE8Kqa:H
ps.getItems()得到已分页好的结果集 7LsVlT[
ps.getIndexes()得到分页索引的数组 "dHo6CT,y_
ps.getTotalCount()得到总结果数 )cU$I)
ps.getStartIndex()当前分页索引 w\a6ga!xt"
ps.getNextIndex()下一页索引 iL|5}x5\
ps.getPreviousIndex()上一页索引 ujf7r`;u.
M'JCT'(X
N!./u(b
hjz`0AS
p\Fxt1Y@X
3Xm>
3
a5 pXn v]A
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 gOr%N!5
M7{_"9X{
,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 8On MtP
0|ekwTx.
一下代码重构了。 {E.A?yej9
B:ugEAo_
我把原本我的做法也提供出来供大家讨论吧: N%9?8X[5
#'y&M t
首先,为了实现分页查询,我封装了一个Page类: ul]hvK{2
java代码: Bh7hF?c Sj
ccT
<UIpq
wli H3vA_
/*Created on 2005-4-14*/ /4;Sxx-
package org.flyware.util.page; ji<(}d~L*
vlFq-W!
/** X|C=Q
* @author Joa +v/-qyA
* ^O!;KIe{g
*/ TLq^5,qG
publicclass Page { 6?a z
.yHi"ss3
/** imply if the page has previous page */ =t
%;mi,M
privateboolean hasPrePage; Ii!{\p!
bX
6uGu
7
/** imply if the page has next page */ #'n.az=1
privateboolean hasNextPage; BS%pS(
e ^ZY
/** the number of every page */ u/V&1In
privateint everyPage; 4I#@xm8)
o5:md :\
/** the total page number */ @|{8/sOq
privateint totalPage; S0ltj8t
:KqSMuKR
/** the number of current page */ <sSH^J4QqX
privateint currentPage;
Tj}%G
FiSx"o
/** the begin index of the records by the current &?5me:aU
Mkr
&30il[
query */ aq\Fh7
privateint beginIndex; ibLx'<
'F3@Xh
sFHqLG{/
/** The default constructor */ 'uF-}_
|
public Page(){ n@6vCdk.
p)VMYu
} E{}J-_oS45
#CcEI
/** construct the page by everyPage r;p@T8k
* @param everyPage !?lvmq
* */ J:OP*/@='
public Page(int everyPage){ 0sH~H[ap
this.everyPage = everyPage; smn~p/u
} B>c2 *+Bk
Q(O0z3 b
/** The whole constructor */ Tp.:2[
public Page(boolean hasPrePage, boolean hasNextPage, _#
cM vlk
Z<QNzJ D
pH(X;OC9S
int everyPage, int totalPage, sp+'c;a
int currentPage, int beginIndex){ Jp|eKZ
this.hasPrePage = hasPrePage; %Y,Ru)5}
this.hasNextPage = hasNextPage; 8l'W[6
this.everyPage = everyPage; =R ZPDu
this.totalPage = totalPage; Bd- &~s^
this.currentPage = currentPage; K_k'#j~*?
this.beginIndex = beginIndex; 9|Ylv:sR
} S9^SW3
3Pp+>{2_?
/** Wf-XH|j[
* @return \.>7w 1p
* Returns the beginIndex. zF|c3ap
*/ iP@FXJJ
publicint getBeginIndex(){ ,v`03?8l(
return beginIndex; C6Cr+TScH
} fs-LaV
0
tx)$4 v
/** ya[f?0b0
* @param beginIndex *.KVrS<B1
* The beginIndex to set. eI-SWwmv/u
*/ #f%fY%5q
publicvoid setBeginIndex(int beginIndex){ mwsdl^c
this.beginIndex = beginIndex; apt$e$g
} :X:s'I4J
D
K;w2qc.+
/** T8%!l40v
* @return j"fx|6l)
* Returns the currentPage. q8n@fi6
*/ y#8 W1%{x
publicint getCurrentPage(){ i`W~-J
return currentPage; QcJC:sP\>
} C%{2 sMJz
78 ]Kv^l^_
/** ;?q}98-2
* @param currentPage <
Wp)Y
* The currentPage to set. \3"B$Sp|=
*/ Vw.)T/B_D
publicvoid setCurrentPage(int currentPage){ GB"Orm.
this.currentPage = currentPage; !"&-k:|g
} bC98<if
>P:U9
b
/** k+*pg4'
* @return fE_%,DJE(
* Returns the everyPage. pzaU'y#PM
*/ 2.=u '
publicint getEveryPage(){ C`.eJF
return everyPage; G e5Yz.Qv
} l)~U8
2`j{n\/
/** A{M7
* @param everyPage iOSt=-p
* The everyPage to set. gs=ok8w
*/ "C(yuVK1G
publicvoid setEveryPage(int everyPage){ >Vg [A
this.everyPage = everyPage; <mj/P|P@
} lpS v
6VuyKt
/** ,>za|y<n
* @return }0Uh<v@
* Returns the hasNextPage. d{t@+}0.u
*/ pzoh9}bue
publicboolean getHasNextPage(){ ]9)iBvQlj
return hasNextPage; #sBL E
} 6 eu7&Kj'
0rz1b6F5,
/** *po
o.Zz
* @param hasNextPage Km!ACA&s6
* The hasNextPage to set. r!O[|h
*/ BFhEDkk
publicvoid setHasNextPage(boolean hasNextPage){
kPiY|EH
this.hasNextPage = hasNextPage; mEu2@3^E }
} N~fE&@-
ULBEe@s
/** jT< I`K*
* @return ?1c7wEk
* Returns the hasPrePage.
;(J&%
*/ '/t9#I@G\
publicboolean getHasPrePage(){ hdcB*j?4
return hasPrePage; >HRNB&]LdP
} ')~V=F
t'0&n3
/** w4CcdpR
* @param hasPrePage *OdmKVw6G
* The hasPrePage to set. J\w4N",
*/ <
W`gfpzO
publicvoid setHasPrePage(boolean hasPrePage){ pL}
F{G.
this.hasPrePage = hasPrePage; g|->W]q@;
} J~4mp\4b
rx 74v!
/** 'DNxc
* @return Returns the totalPage. IVZUB*wv)b
* @$ Nti>
*/ <66%(J>
publicint getTotalPage(){ TC44*BHq
return totalPage; }{j@q~w>$
} Mis B&Ok`k
i$$h6P#
/** }9W[7V?
* @param totalPage Vdefgq@<
* The totalPage to set. Y`{62J8oy
*/ ,c$tKj5ulQ
publicvoid setTotalPage(int totalPage){ ujkWVE'
this.totalPage = totalPage; Y\WVkd(+G
} lY(_e#
>o v#\
} R@s|bs?
i+in?!@G:
!Q_Wbu\U
G`jvy@
b_6cK#
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 7FyE?
GnUD<P=I
个PageUtil,负责对Page对象进行构造: [KHlApL
java代码: s]6;*mI2
"crp/Bj?
OFmHj]I7=
/*Created on 2005-4-14*/ LAnC8O
package org.flyware.util.page; !OQ5AF$
4)k-gKS*
import org.apache.commons.logging.Log; rNo/H<J%+j
import org.apache.commons.logging.LogFactory; hGw}o,g
.9=4Af
/** MUv#8{+F'/
* @author Joa C'y2!Q/"
* U^
,!
*/ Vy[xu$y
publicclass PageUtil { (ER9.k2
Wa.xm_4s2
privatestaticfinal Log logger = LogFactory.getLog 8Dtpb7\o
r-L& ee
(PageUtil.class); L@=$0p41;
#Y3-P
/** b=\chCRJJ
* Use the origin page to create a new page WQ8 "Jj?k6
* @param page @x}^2FE
* @param totalRecords G~bDl:k`A
* @return O CIoY?a
*/ yocFdI
publicstatic Page createPage(Page page, int 4e
eh+T
RXcN<Y&
totalRecords){ r-!Qw1
return createPage(page.getEveryPage(), ^2 H-_
.K(9=yh
page.getCurrentPage(), totalRecords); !X$19"
} %HtgZeY
~$C<^?"b
/** Gos#=H
* the basic page utils not including exception AkW>*x
BY[7`@
handler WjK[% ;Z!
* @param everyPage ok:L]8UN3
* @param currentPage B0)|sH
* @param totalRecords 3 )#Nc|
* @return page #}@8(>T
*/ 8q{|nH
publicstatic Page createPage(int everyPage, int tu$rVwgM
{~FPvmj&
currentPage, int totalRecords){ "+7E9m6I
everyPage = getEveryPage(everyPage); 1:^Xd~X
currentPage = getCurrentPage(currentPage); r,Xyb`
int beginIndex = getBeginIndex(everyPage, XMkRYI1~
){#INmsF
currentPage); pg7~%E4
int totalPage = getTotalPage(everyPage,
JrLh=0i9
y9/nkF1p
totalRecords); [a!AKkj
boolean hasNextPage = hasNextPage(currentPage, 6("bdx;!
@MTv4eC}e
totalPage); @~|;/OY>"
boolean hasPrePage = hasPrePage(currentPage); x*'H@!!G
Pp8G2|bz
returnnew Page(hasPrePage, hasNextPage, I;E?;i
everyPage, totalPage, Wu|MNB?M
currentPage, X"q[rsB
/ILd|j(e
beginIndex); eIF6f&
F
} >lQa"F=
D]*|Zmr+}
privatestaticint getEveryPage(int everyPage){ }i^|.VZZ
return everyPage == 0 ? 10 : everyPage; VY8cy2
} Cm%I/4
n&P~<2^M#
privatestaticint getCurrentPage(int currentPage){ %~M* <pN
return currentPage == 0 ? 1 : currentPage; DW9MX`!Xc
} o_mjI:
<dD!_S6@,
privatestaticint getBeginIndex(int everyPage, int ~@l4T_,k
bfoTGi
currentPage){ uHZ4
@w:
return(currentPage - 1) * everyPage; u<fZ.1
} >K,QP<B
^W:a7cMw
privatestaticint getTotalPage(int everyPage, int : Bo
xxl|j$m
totalRecords){ _z BfNz9D
int totalPage = 0; =Hd#"9-
@M-w8!.~
if(totalRecords % everyPage == 0) }}]Lf 3;
totalPage = totalRecords / everyPage; _Y&.Nw
else 6=$<R4B
totalPage = totalRecords / everyPage + 1 ; V-go?b`
F09%f"9
return totalPage; "h[)5V{
} 1`L.$T,1!
$"|r7n5[
privatestaticboolean hasPrePage(int currentPage){ )LKJfoo
PY
return currentPage == 1 ? false : true; cf"&22TQ+Z
} E%D .a=UX,
|k*bWuXgLs
privatestaticboolean hasNextPage(int currentPage, <W8%eRfU
l P=I0A-
int totalPage){ e<1Ewml(]
return currentPage == totalPage || totalPage == 0wVM%Dng
^Ld5<
0 ? false : true; #9[>
} DMch88W
\SQ4yc
^(C4Q?[2m
} 3'0vLi
>]ux3F3\
I)` +:+P
^VMCs/g6
j][&o-Ev
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 XPMUhozV
\C>IVz<O
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 ;K8}Yq9p9
Yu)GV7\2
做法如下: SS`\_@ci
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 F4T!&E%6
N]/cBGy
的信息,和一个结果集List: Km=
Y^x0
java代码: )b]wpEFl
=,N"% }
Ekq(
/*Created on 2005-6-13*/ "k @[7
7
package com.adt.bo; Pi?G:IF
965 x_
%
import java.util.List; >Q@y8*E\F
Os>&:{D 4!
import org.flyware.util.page.Page; (Ytr&gh;0
Et}%)M
/** d{NMG)`x\
* @author Joa S
WTZ6(!oW
*/ %SIll
publicclass Result { ?K2EK'-q
t~K[`=G\ex
private Page page; GEVDXx>@
'do2n/
private List content; Uq'W<.v5
S{e3aqT#N
/** 9<3}zwJ
* The default constructor dg#Pb@7a
*/ C|Gk}
public Result(){ VV$#<D<)
super(); j?o6>j
} qvy*;
<w
RiR],Sj
/** x!s=Nola
* The constructor using fields QbHX.:C
* 9QHj$)?k,
* @param page yZp/P %y
* @param content |gxPuAXa)
*/ gS[B;+d
public Result(Page page, List content){ ;g#nGs>
this.page = page; 7w9'xY
this.content = content; tx<^PV2
} hVB(*WA^D
Q wG_-
/** ZEDvY=@a
* @return Returns the content. q+8de_"]
*/ 7\g#'#K
publicList getContent(){ 19O
return content; b#6mUl2
} 4,:I{P_>6B
T'lycc4~a
/** L |#0CRiN
* @return Returns the page. zq$L[X
*/ +\ "NPK@3
public Page getPage(){ Ue;Z)}
return page; (r?hD*2r
} @IbZci)1
H6nH
/** Y$,~"$su|
* @param content v36Z*I6)5
* The content to set. ^4]=D nd%
*/ V+lS\E.
public void setContent(List content){ IOxtuR
this.content = content; "S'Yn-
} (m Yi
*rxYal4ad
/** $u, 6x~>
* @param page Ici4y*`M
* The page to set. 7;TMxO=bra
*/ ,37<FXX,
publicvoid setPage(Page page){ =c,7uB
this.page = page; D{7^y>8_Y-
} <a_(qh@B
} "v0bdaQH3
,m0M:!hK
mc2uI-W
wS,fj gX
7>r[.g
2. 编写业务逻辑接口,并实现它(UserManager, |"Zf0G
^K J#dT
UserManagerImpl) 9:xs)t- _
java代码: z8kebS&5
V,& OO
e#}Fm;|d
/*Created on 2005-7-15*/ -\%5aXr
package com.adt.service; (4q/LuP^d
j$6Q]5KdoS
import net.sf.hibernate.HibernateException; ,2FI?}+R
jp4-w(
import org.flyware.util.page.Page; 54WX#/<Yik
,S(Z\[x0
import com.adt.bo.Result; Hq>hnCT
c]U+6JH
/** znWB.H
* @author Joa 4IY|<
*/ ,vMAX?c
publicinterface UserManager { gWj r|m<
Br<lP#u=G
public Result listUser(Page page)throws :}#)ipr
4DL2
A;T
HibernateException; /|&4&$
>tMI%r
} <9xr?i=
{!?M!/d
F3o"ETle
~9k E.
^ ~1QA
java代码: s%vy^x29
qW4\t
>Sw?F&
/*Created on 2005-7-15*/ ra^%__N}
package com.adt.service.impl; Ax=)J{4v
}z9v*C
import java.util.List; &ZFHWI(P
6pC1C.
import net.sf.hibernate.HibernateException; Vz-q7*o$S
csJ)Pt?d
import org.flyware.util.page.Page; ~W4SFp
import org.flyware.util.page.PageUtil; :?ZrD,D
2$t%2>1>@
import com.adt.bo.Result; pNQ7uy
import com.adt.dao.UserDAO; |Go$z3bx
import com.adt.exception.ObjectNotFoundException; s]A8C^;c
import com.adt.service.UserManager; >fT%CGLC0
#M#$2Vt
/** hHDLrr
* @author Joa bJ6C7-w:wa
*/ Q;q{1M >
publicclass UserManagerImpl implements UserManager { ?D9iCP~~
hG<[F@d
private UserDAO userDAO; -nUK%a"(D
k}}'fA
/** CsT&}-C
* @param userDAO The userDAO to set.
8sI$
*/ D ZZRu8~
publicvoid setUserDAO(UserDAO userDAO){ #^aa&*<D_
this.userDAO = userDAO; sc# EL~
} G*%U0OTi
H)&iFq
/* (non-Javadoc) _):@C:6
* @see com.adt.service.UserManager#listUser ;P8%yf
`YZl2c<w*
(org.flyware.util.page.Page) a
^juZ
*/ K/}x'*=
public Result listUser(Page page)throws {^;7DV:
?uJX
HibernateException, ObjectNotFoundException { 2Ir*}s2{
int totalRecords = userDAO.getUserCount(); 3'A0{(b
if(totalRecords == 0) fJk'5kv
throw new ObjectNotFoundException Sj/v:
F9las#\J
("userNotExist"); s?9Y3]&+&M
page = PageUtil.createPage(page, totalRecords); #k>A,
List users = userDAO.getUserByPage(page); L>7@!/9L
returnnew Result(page, users); qJonzFp7
} \x4:i\Fx@
D Vg$rm`
} }[@Q**j(
W
9}xfy09
cud9oJ-=;
7D 3-/_ v
>/}p{Tj
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 s!MD8ia
kj4=Q\Rfm
询,接下来编写UserDAO的代码: <*u^8lCA
3. UserDAO 和 UserDAOImpl: @;hdZLG]`&
java代码: `*kl> }$
i<tJG{A=
!SnLvW89Z
/*Created on 2005-7-15*/ '<ZHzDW@
package com.adt.dao; kou7_4oS
4
540Lw'A
import java.util.List; ${wp}<u_
RDy&i
import org.flyware.util.page.Page; lt2MB#
;qWSfCt/^
import net.sf.hibernate.HibernateException; "VoufXM:
;g2UIb?{6
/** +7_U(|gO
* @author Joa ]Z85%q^`
*/ B~&}Mv
publicinterface UserDAO extends BaseDAO { *|CvK&7
D8Mq '$-
publicList getUserByName(String name)throws 5.yiNWh
II~91IEk
HibernateException; R@_3?Z!W=
sD{Wc%5
publicint getUserCount()throws HibernateException; kw2d<I$]
`2x. -
publicList getUserByPage(Page page)throws ^rjUye%EK
7ju38@+
HibernateException; jk\V2x@DR
zA3r&stN+
} IQ-l%x[fue
asmu<
anfnqa8
\\Q){\S
3kF+wifsz
java代码: t6\--lk_
V+l7W
0E
(G1o'
/*Created on 2005-7-15*/ q0vZR"y
package com.adt.dao.impl; ]A#:Uc5
R>;&4Sjr
import java.util.List; oEFo7X`t
a{rUk%x
import org.flyware.util.page.Page; v?Cakwu
O2="'w'kR
import net.sf.hibernate.HibernateException; =]pEvj9o
import net.sf.hibernate.Query; &o1k_!25
V*Xr}FE
import com.adt.dao.UserDAO; WQD:~*C:
6uUn
/** Z*h}E
* @author Joa fZ;}_wR-H
*/ G8/q&6f_
public class UserDAOImpl extends BaseDAOHibernateImpl \$ss
8_S| 8RW(
implements UserDAO { .j**>&7L
elpTak@
/* (non-Javadoc) /_Ku:?{
* @see com.adt.dao.UserDAO#getUserByName {{gt>"D,
T-/3
A%v
(java.lang.String) FCKyKn
*/ =20
+(<
publicList getUserByName(String name)throws ji.?bKqHE
EN}XIa>R
HibernateException { tXZMr
String querySentence = "FROM user in class )/~o'M3
]fU&?z#
com.adt.po.User WHERE user.name=:name"; H~>8q~o]
Query query = getSession().createQuery 9nFWJn
KH=3HN}
(querySentence); $\~cWpv
query.setParameter("name", name); w1VYU>
return query.list(); "5sA&^_#_
} T.-tV[2
zn_#}}e;G
/* (non-Javadoc) 7-~)/7L
* @see com.adt.dao.UserDAO#getUserCount() *">CEQ[MT
*/ 9d(#/n
publicint getUserCount()throws HibernateException { C+5X8
int count = 0; Fr;
's(^
String querySentence = "SELECT count(*) FROM ZW0\_1
}&2,!;"">3
user in class com.adt.po.User"; U[8F{LX
Query query = getSession().createQuery C8|#
1\Pjz
Lj
(querySentence); *,*O.#<6
count = ((Integer)query.iterate().next %.l={B,i
*vEj\
()).intValue(); tns8B
return count; V|}9bNF
} iSW<7pNq0
^yq}>_
/* (non-Javadoc) vNl)ltzJF
* @see com.adt.dao.UserDAO#getUserByPage dga4|7-MY
BGwD{6`U
(org.flyware.util.page.Page) l"DHG`kb
*/ ,R3TFVV!?
publicList getUserByPage(Page page)throws m.! M#x2!
Di4GaKa/
HibernateException { >w,jaQ
String querySentence = "FROM user in class ~w|h;*Bj
'gg<)Bd
com.adt.po.User"; g`fMHU7
Query query = getSession().createQuery i^ |G
3/yt
(querySentence); dC-~=}HR^
query.setFirstResult(page.getBeginIndex()) KRcB_(
.setMaxResults(page.getEveryPage()); sK&kp=zu
return query.list(); @F$}/
} {2D|,yH=
)cZHBG.0H
} P3Lsfi.
SE6(3f$
Gau@RX:O
jX(${j<
YZSQOLN{
至此,一个完整的分页程序完成。前台的只需要调用 F'|e:h
_od /)#
userManager.listUser(page)即可得到一个Page对象和结果集对象 WG,1%=M@
G
kG#+C0L
的综合体,而传入的参数page对象则可以由前台传入,如果用 Pc< "qy
y %61xA`#
webwork,甚至可以直接在配置文件中指定。 ?E|=eO"I1
{f)aFGp
下面给出一个webwork调用示例: SG|AJ9
java代码: vc p{Gf|^
&ZkJ,-
i$@xb_
/*Created on 2005-6-17*/ JehanF[
package com.adt.action.user; hif;atO
ort*Ux)
import java.util.List; V:J|shRo
,IqE<i!U
import org.apache.commons.logging.Log; <PuY"-`/Oc
import org.apache.commons.logging.LogFactory; ]w _&%mB
import org.flyware.util.page.Page; A46q`l9B
FK~wr;[
import com.adt.bo.Result; qK#"uU8B
import com.adt.service.UserService; eF.nNu
import com.opensymphony.xwork.Action; ol/@)k^s>
7 =}tJ
/** [ij) k@.
* @author Joa Y,Z$U| U
*/ 0|tyKP|J
publicclass ListUser implementsAction{ jLI1Ed
iJOG"gI&
privatestaticfinal Log logger = LogFactory.getLog *<:X3|3E
3!gz^[!?EN
(ListUser.class); 0[%{YmI{W
)^s>2 1
private UserService userService;
lqL5V"2Y
Ea<\a1Tl43
private Page page; 1R~$m
%po;ih$jr*
privateList users; Zn
r4^i&(
mIYKzu_k=
/* R$
+RTG:E
* (non-Javadoc) BV>9U5
* 1)
2-UT
* @see com.opensymphony.xwork.Action#execute() lV^:2I/
*/ e4Y+u8gT
publicString execute()throwsException{ Eze w@*(
Result result = userService.listUser(page); l9eTghLi
page = result.getPage(); L3wj vq^
users = result.getContent(); R"O%##Ws
return SUCCESS; Oi: Hs
} "'Fvt-<^S7
P(7el
/** 2(3Q#3V
* @return Returns the page. Hkia&nz'3
*/ ~b)X:ku
public Page getPage(){ E8sM`2z5
return page; WeH_1$n5
} W[)HFh(#
t6KKfb
/** ,WOCG2h
* @return Returns the users. {{P 3Z[
*/ !=.y[Db=
publicList getUsers(){ eza"<uBr
return users; YzZj=]\`b
} -th.(eAx
CckfoJ 9
/** ]rY9t@
* @param page 'G % ]/'_U
* The page to set. DPW^OgL;
*/ Lc}hjK
publicvoid setPage(Page page){ W9c&"T9JT
this.page = page; ,D`jlY-1l
} 6<S-o|Xw
R||$Rfe
/** M61Nl)|mx&
* @param users lc5(^~
* The users to set. $X)|`$#pL#
*/ b1IAp >*2l
publicvoid setUsers(List users){ ]JGq{I>%+6
this.users = users; jsgDJ}
} R#~l[S8u^
*.wj3'wV
/** :EHk]Hkz
* @param userService DpmAB.
* The userService to set. oO?+2pTQV
*/ Q!IqvmO
publicvoid setUserService(UserService userService){ lW#2 ox
this.userService = userService; 1:T"jsWw
} ]Ri=*KZa
} xV14Y9
H'!OEZ
'*Dp2Y{7
0#Ug3_dfr
qlPIxd
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,
g fAWN
@YaI5> ,/
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 pd: YR;
lj&\F|-i
么只需要: ol_\ "
java代码: !WlL RkwO
8lqmd1v
W!XBuk-
<?xml version="1.0"?> QwFA0
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork ip'{@1L
Kg<~Uf=1
1.0//EN" "http://www.opensymphony.com/xwork/xwork-
R7z @y o
N6_1iIM
1.0.dtd"> SFuSM/Pf
Ei]SksV>*
<xwork> b g0ix"
Xqm?@JN
<package name="user" extends="webwork- rBL2A
kP('X/
interceptors"> M+ <SSi"
^5~x*=_
<!-- The default interceptor stack name 5GJkvZtFY
E3S0u7Es
--> 0)K~pV0aT
<default-interceptor-ref n>Oze7hVY
*HV_$^)=
name="myDefaultWebStack"/> %K\B)HR
dly -mPmP
<action name="listUser" mz<,nR\
XHgW9 ;M!
class="com.adt.action.user.ListUser"> y[jp)&N`
<param 0VJHE~Bgi
zD8$DG8
name="page.everyPage">10</param> o\it]B
<result #H Jlm1d
@ kv~2m
name="success">/user/user_list.jsp</result> 0;`FS/[(f
</action> %UooZO
h'G
</package> wt@TR~a
IR2Qc6+{
</xwork> @0H0!9'
Bo
ywgL|
h1 "#
vzSjfv
PW"?*~&
?@MY +r_G
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
M54czo=l
ZK2&l8
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。 Fpn'0&~-fi
^P [#YO
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 A`(Cuw-o
6yYd~|T.Fl
.pl,ujv
@*6_Rp"@
o^d|/;
我写的一个用于分页的类,用了泛型了,hoho }NV<k
dn=srbJ
java代码: SV95g@
Um`KmM3
/s(PFN8#Y
package com.intokr.util; n2c(x\DA&
^l
;Bo3^_
import java.util.List; U~7{q
>
z8D,[`
/** I)*J,hs1
* 用于分页的类<br> =:R${F
* 可以用于传递查询的结果也可以用于传送查询的参数<br> 6b` Jq>v
* 6+s&%io4
* @version 0.01 $j(4FyH\
* @author cheng X9" T(`
*/ 'f %oL/,
public class Paginator<E> { ^pfM/LQ@
privateint count = 0; // 总记录数 Pq-@waH3
privateint p = 1; // 页编号 oz3!%'
privateint num = 20; // 每页的记录数 Zcc7
7dRA
privateList<E> results = null; // 结果 4RQ38%> >j
3|3ad'
/** B<@a&QBTg
* 结果总数 MScUrW!TA
*/ v33[Rk'
publicint getCount(){ =:xJZy$
return count; _m#TL60m
} L5&,sJz
FO]f 4@
publicvoid setCount(int count){ .OW5R*
this.count = count; %.uN|o&n
} Mj19;nc0I
l<"B[
/** G[zy sxd
* 本结果所在的页码,从1开始 mkBQTQGT
* .rDao]K
* @return Returns the pageNo. 8|hi2Qeu,c
*/ 3%x-^.
publicint getP(){ Xh~oDnP
return p; [c=![*}/
} b4ke'gx
P=9sP:[f6
/** F*:H&,
* if(p<=0) p=1 DAMw(
* hSh^A5
/
* @param p #fyY37-
*/ =7-kD3
publicvoid setP(int p){ H3JDA^5
if(p <= 0) 8L@@UUjr
p = 1; e5ww~%,
this.p = p; RD:LNl<0sh
} = j
l(Q
'@QK<!%,
/** ]<fZW"W<q
* 每页记录数量 *Hh*!ePp
*/ hH?ke(&=f
publicint getNum(){ _B}QS"A
return num; oJ=u
pnBn-
} diw5h};W
PCKxo;bD
/** fjQIuM
* if(num<1) num=1 kY~yA2*G
*/ ,fm{
krE
publicvoid setNum(int num){ TjctK [db@
if(num < 1) KZ [:o,jp>
num = 1; >4T7DMy
this.num = num; MF::At[4
} k@9q5lu;T
2+LvlS)C
/** U4e9[=q`'
* 获得总页数 z-S8s2.Fd
*/ 7H[.o~\
publicint getPageNum(){ 6SSrkj }U
return(count - 1) / num + 1; ?Y$3R"p@3`
} /q`f3OV"
ia-&?
/** ,=}+.ax
* 获得本页的开始编号,为 (p-1)*num+1 mx^rw*'JGC
*/ QVN@B[9
publicint getStart(){ $)(Zt^
return(p - 1) * num + 1; @Z~0!VY
} \'nE{
1a},(ZcdX
/** .noY[P8i
* @return Returns the results. QVR-`d/
*/ 9Bu=8P?
publicList<E> getResults(){ hN1{?PQ
return results; ). HnK
} K5d>{c
LS1}j WU!
public void setResults(List<E> results){ 4+0:(=>[%
this.results = results; B|BJkY'
} W4AFa>h
G9>
0w)r
public String toString(){ `XbV*{7
StringBuilder buff = new StringBuilder C5#$NV99p
A Rjox`
(); IAbH_+7O
buff.append("{"); sVIw'W
buff.append("count:").append(count); \OF"hPq
buff.append(",p:").append(p); 2 wZyUB;
buff.append(",nump:").append(num); UrB{jS?
buff.append(",results:").append 5CM]-qbf@
t*!Q9GC_
(results); &eX^ll
buff.append("}"); }Q>??~mVl
return buff.toString(); x$V[xX
} /57)y_ \
Pexg"328
} )G9,5[
q VJC O-K|
y8O<_VOO}"