Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 /yI4;:/
$4{sPHi)I
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 1K9.3n
v[
iJ(C_
据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 <O+GXJ2
a}@b2Wc*
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 <MS>7Fd2
tNY;wl:wp
。 0S5xmEzop
1?.CXqK
分页支持类: _x.2&S89
.+9*5
java代码: M`&t=0D
ZN}`A7
Z,)H f
package com.javaeye.common.util; +v
B}E
2'fd4rE5
import java.util.List; |XB<vj07G
ql@2<V{
publicclass PaginationSupport { d#T5=5#
eX$KH;M
publicfinalstaticint PAGESIZE = 30; toY_1
V48_aL
privateint pageSize = PAGESIZE; ?$/::uo
qArR5OJ
privateList items; gkmof^
U;bx^2<m
privateint totalCount; )xcjQkb
VZqCFE3
privateint[] indexes = newint[0]; &4OJJ9S
Ar>B_*dr
privateint startIndex = 0; )|=1;L
nFlN{_/
public PaginationSupport(List items, int fK7
?"^`/
k1z`92"
totalCount){ r-T1^u
setPageSize(PAGESIZE); .JKH=?~\
setTotalCount(totalCount); Tt~4'{Bc
setItems(items); JzEg`Sn^
setStartIndex(0); E{V?[HcWq
} F$8:9eL,T
bhUE!h<
public PaginationSupport(List items, int &n1Vv_Lb
[k
7HLn)
totalCount, int startIndex){ 8U@f/P
setPageSize(PAGESIZE); o`CM15d*7o
setTotalCount(totalCount); RFbf2s\t
setItems(items); ;}Jv4Z
setStartIndex(startIndex); ~m fG
Yk"
} Q9cSrU[$
cpk\;1&t
public PaginationSupport(List items, int 3rRIrrYO
W<q<}RSn
totalCount, int pageSize, int startIndex){ ]pm/5|
setPageSize(pageSize); yq.@-]ytZ
setTotalCount(totalCount); K["rr/
setItems(items); S5JMt;O
setStartIndex(startIndex); T}!9T!(HdF
} H{=]94
q&:7R
.Ci
publicList getItems(){ 4Y?fbb<
return items; &~eCDlX/
} [lIX&!T"
d>Tv?'o`q
publicvoid setItems(List items){ <7y/)b@
this.items = items; IS8 sJ6")
} V~PGmn[V
:NLY;B`
publicint getPageSize(){ ?*V\
-7jg
return pageSize; uV gA <*0
} e^*&&
~Y43`@3H:
publicvoid setPageSize(int pageSize){ d\qszYP[
this.pageSize = pageSize; EF&CV{Sw
} iU+SXsXLR4
fmYx
publicint getTotalCount(){ GpPM ?
return totalCount; /[ m7~B]QE
} qD%88c)g
xlZh(pf
publicvoid setTotalCount(int totalCount){ J-+mdA
if(totalCount > 0){ F$>#P7ph\a
this.totalCount = totalCount; !l dE9 .
int count = totalCount / '[6]W)f
:&5u)
pageSize; BUZ74
if(totalCount % pageSize > 0) zecM|S _
count++; YQ+8lANC
indexes = newint[count]; X%-"b`
for(int i = 0; i < count; i++){ 7VfXE/
indexes = pageSize * mmwc'-jU:
idBdaZg
i; n jd2
} 1f3g5y'z5
}else{ R)d_0Ng
this.totalCount = 0; 3B[tbU(
} 4qDa:D"5
} g&RhPrtl
`Zp*?
publicint[] getIndexes(){ [W$x5|Z}Q
return indexes; E_&;.hw
} 0Runex[
atZNX1LD[/
publicvoid setIndexes(int[] indexes){ "o%okN
this.indexes = indexes; no\G
>#
} 1V5N)ty
[*K9V/
publicint getStartIndex(){ %dw0\:P?Q
return startIndex; 8F\'?7
} D7R;IA-w
/slCK4vFc
publicvoid setStartIndex(int startIndex){ H1~9f{
if(totalCount <= 0) CWZv/>,%
this.startIndex = 0; Z3zD4-p$_
elseif(startIndex >= totalCount) LP7jCt
this.startIndex = indexes ZLaht(`+
`?&C5*P
[indexes.length - 1];
w)go79
elseif(startIndex < 0) "pX|?ap
this.startIndex = 0; Lniz>gSc
else{ ;U0w<>4L
this.startIndex = indexes J}Z\I Y,
0XE6Hw
[startIndex / pageSize]; Y)8 Py1}
} PtPx(R3
} _ y'g11 \
5:+x7Ed
publicint getNextIndex(){ g:^Hex?Yfd
int nextIndex = getStartIndex() + &iuMB0rbu
Yk{4 3yw
pageSize; c ~M'O26bW
if(nextIndex >= totalCount) r"L:Mu
return getStartIndex(); 1"A"AMZf
else H(?+-72KX
return nextIndex;
B*`[8kb,
} DbI)tDi5D
=f=>buD
publicint getPreviousIndex(){ {JQV~rfh`
int previousIndex = getStartIndex() - ,~=+]9t
abVEi[nP
pageSize; QeQwmI
if(previousIndex < 0) uf)!SxT
return0; j0cB#M44
else +IGSOWL
return previousIndex; &mJm'Ks
} ;[C_ho
4\U"e*
} 9nd,8Nji
N+UBXhh
oj6=.
)CH\]>-FO
抽象业务类 ckdCd
J
java代码: dpdp0
j%S}
T)pX
mg3YKHNG
/** ZV/g_i#
* Created on 2005-7-12 9-Qu5L~
*/ Ta8lc %0w3
package com.javaeye.common.business; IYr4
F6{Q1DqI
import java.io.Serializable; 93)1
import java.util.List; VyIM ,glu
/z1-4:^`A[
import org.hibernate.Criteria; *6(/5V
import org.hibernate.HibernateException; nqYarHi
import org.hibernate.Session; V[*<^%
import org.hibernate.criterion.DetachedCriteria; ~c,+)69"T
import org.hibernate.criterion.Projections; ZB$,\|^6
import {f6~Vwf
['c*<f"
D2
org.springframework.orm.hibernate3.HibernateCallback; %Bn n\{Az
import 0#sf,ja>
DS<E:'N
org.springframework.orm.hibernate3.support.HibernateDaoS x1+ V
{us#(4O
upport; 9Kc;]2m
(Ixmg=C6y
import com.javaeye.common.util.PaginationSupport; ,Igd<A=
z}$!B.)
public abstract class AbstractManager extends 4n\O6$&.x
8(@(G_skp
HibernateDaoSupport { ]1bN cq2I
eeUEqM$7EX
privateboolean cacheQueries = false; L# .vbf
Ap(>mUs!i
privateString queryCacheRegion; CDFX>>N
;3O=lo:$~
publicvoid setCacheQueries(boolean ^hwTnW9Z1:
}@A{'q5y
cacheQueries){ 4:s!mHcz
this.cacheQueries = cacheQueries; .Nd_p{
} @ojV8
&~N@M!`Dn
publicvoid setQueryCacheRegion(String kSqMI'89
UTxqqcqEny
queryCacheRegion){ y=e|W=<D&
this.queryCacheRegion = )O6_9f_
eBlB0P
queryCacheRegion; <`=(Ui$fD
} O&PrO+&
jW.IkG[|
publicvoid save(finalObject entity){ "&TN}SBW
getHibernateTemplate().save(entity); wn>?r
?KIB
} {dNWQE*\c
)WF*fcx{
publicvoid persist(finalObject entity){ S4>1 d-
getHibernateTemplate().save(entity); K1|xatx1V
} ?wj1t!83
$s9YU"
publicvoid update(finalObject entity){ "xMnD(p
getHibernateTemplate().update(entity); D]5cijO6
} R|t.JoP9
#7,;/rtO7
publicvoid delete(finalObject entity){ ujoJ6UOG
getHibernateTemplate().delete(entity); F@@6D0\X?
} tq8rG@-C
a*UxRi8
publicObject load(finalClass entity, !L55S03
ty)~]!tA
finalSerializable id){ ]n&Eb88
return getHibernateTemplate().load 6+_qGV
Ub*O*nre
(entity, id); CW;=q[+w
} \XgpwvO".
>0jg2vqt
publicObject get(finalClass entity, {w VJv1*l
&/]g@^h9
finalSerializable id){ )p+6yH
return getHibernateTemplate().get K Fn[
drf?7%v
(entity, id); jf~-;2
} @6z]Xb
8\_ YP3
publicList findAll(finalClass entity){ #bdSH)V
return getHibernateTemplate().find("from <lHVch"(^$
M@78.lPS
" + entity.getName()); L[.RV*sL
} r2xIbZ
l]__!X
publicList findByNamedQuery(finalString u+,
bZzB\FB~
namedQuery){ _(J/$D
return getHibernateTemplate 1usLCG>w{
9/I|oh_
G
().findByNamedQuery(namedQuery); xe!6Pgcb
} C.q4rr
|qX[Dk
publicList findByNamedQuery(finalString query, )i*- j=
tU>?j1
finalObject parameter){ H.]rH,8
return getHibernateTemplate ,e5#wz
-_"6jU
().findByNamedQuery(query, parameter); :]k`;;vh
} $"6O92G(hJ
U8R*i7
publicList findByNamedQuery(finalString query, pv ;ZR
^+'\
u;\
finalObject[] parameters){ 7!%xJ!
return getHibernateTemplate X) xeq
&Uu8wFbIJ
().findByNamedQuery(query, parameters); I`FqZw
} DE _<LN
h}cR>
publicList find(finalString query){ 7C@%1kL
return getHibernateTemplate().find "3X~BdH&J
"jMSF@lr
(query); k_hs g6Ur.
} Ij9ezNZT=
%[H|3
publicList find(finalString query, finalObject a\?-uJ+
4-veO3&.h
parameter){ b1ma(8{{{
return getHibernateTemplate().find 3"y,UtKGa
wj#A#[e
(query, parameter); LyA}Nd]pyq
} o!>h
Q#h
C p.qL
public PaginationSupport findPageByCriteria pLea 4
;f+bIYQz
(final DetachedCriteria detachedCriteria){ Y5?OJO{h"
return findPageByCriteria El:&
$%BNoSK
(detachedCriteria, PaginationSupport.PAGESIZE, 0); EHqcQx`K_
} E-J<%+
-Ay=*c.4
public PaginationSupport findPageByCriteria ^4 ?LQ[t'
@fO[{V
(final DetachedCriteria detachedCriteria, finalint l.`f^K=8
kcN#g-0
startIndex){ z*B-`i.
return findPageByCriteria F>/"If#
b'$fr6"O1
(detachedCriteria, PaginationSupport.PAGESIZE, p`2w\P3;)
oVYW'~OID
startIndex); , UiA?7k
} =9y&j-F
5x/LHsr=m
public PaginationSupport findPageByCriteria rf]'VJg#3
+ tza]r:
(final DetachedCriteria detachedCriteria, finalint 5svM3 #
2{fPQQ;#
pageSize, iX\]-_D
finalint startIndex){ .`Rju|l
return(PaginationSupport) nYbI =_-
<Gkmk?x`A
getHibernateTemplate().execute(new HibernateCallback(){ z)&ZoSXWc
publicObject doInHibernate ^7>k:|7-t
G~N$bF^R)
(Session session)throws HibernateException { *N!>c&8
Criteria criteria = ?3|jB?:k
I`
+%ab
detachedCriteria.getExecutableCriteria(session); qGrUS_~q*
int totalCount = s%l`XW;v
5`H.{4@
((Integer) criteria.setProjection(Projections.rowCount !H/5Ud9
_q<Ke/
()).uniqueResult()).intValue(); 1'Y7h;\~\
criteria.setProjection QdtGFY4f,
&h_do8R
(null); eUeOyC
List items = N^;rLrm*
" }oH3L
criteria.setFirstResult(startIndex).setMaxResults (f `zd.
{]V+C=`
(pageSize).list(); ,3~[cE<4
PaginationSupport ps = ?|,-Bft3
gOL-b9W
new PaginationSupport(items, totalCount, pageSize, |QcE5UC
.R5(k'g?
startIndex); LOX}
return ps; /_.1f|{B
} ?f'iS#XL
}, true); mX&!/U
}
I("lGY
g;To}0H
public List findAllByCriteria(final Kdr7JQYzuz
Ia!B8$$'RP
DetachedCriteria detachedCriteria){ ywj'S7~A
return(List) getHibernateTemplate Wd<|DmSy
5,Hj$v7fe
().execute(new HibernateCallback(){ ;2%8tV$V
publicObject doInHibernate 3:~ *cU
W&`{3L
(Session session)throws HibernateException { m(o^9R_=^9
Criteria criteria = "nQ&~KQ
lz>>{
detachedCriteria.getExecutableCriteria(session); )E>nr
Z
return criteria.list(); <yxy ;o
} K 0Gm ?(
}, true); 6Ud6F t6
} {$fd?| 9h
l`k""f69W
public int getCountByCriteria(final u-%|ZSg
!Un&OAy.!
DetachedCriteria detachedCriteria){ _Z{EO|L
Integer count = (Integer) yHNx,ra
z8-dntkf
getHibernateTemplate().execute(new HibernateCallback(){ 7wB*@a-
publicObject doInHibernate H{CiN
L-z9n@=8\
(Session session)throws HibernateException { Gw1Rp
Criteria criteria = N&jHU+{OU
:Cdqj0O3u
detachedCriteria.getExecutableCriteria(session); J*FUJT
return EPu-oE=HW4
UZJ<|[
criteria.setProjection(Projections.rowCount +pG[
[}/
v_L2>Pa.
()).uniqueResult(); &@rXt!
} J_eu(d[9
}, true); On*pI37(\
return count.intValue(); kX)QHNzP
} .mwB'Ll
} +]dh`8*8>1
&$L6*+`h#
N3$%!\~O
Zc|V7+Yx
Y7_2pGvZ
Z;M th#
用户在web层构造查询条件detachedCriteria,和可选的 %`)lCK)2
Yx3ivjX.>
startIndex,调用业务bean的相应findByCriteria方法,返回一个 -~=?g9fGm6
_-c1" Kl
PaginationSupport的实例ps。 vp|'Yy(9z
\qZ>WCp>r
ps.getItems()得到已分页好的结果集 J{qsCJiB
ps.getIndexes()得到分页索引的数组 >_'0 s
ps.getTotalCount()得到总结果数 $/#F9>eZ
ps.getStartIndex()当前分页索引 ;6AanwR6
ps.getNextIndex()下一页索引 \S]` { kY,
ps.getPreviousIndex()上一页索引 YU ,fx<c
] =*G[
wT>~7$=L{
U!O"f
1<;RI?R[9
T]UrKj/iF
,+GS.]8<
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 j{&$_
f~t5[D(\Q,
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 x +]ek
s8V:;$ !
一下代码重构了。 /mG-g%gE
u?7^+z
我把原本我的做法也提供出来供大家讨论吧: G<M9 6V
u8r<B4k
首先,为了实现分页查询,我封装了一个Page类: B]#^&89wG)
java代码: F_d>@-<
8Ao-m38
;q&uk-
/*Created on 2005-4-14*/ U
uEm{
package org.flyware.util.page; Dt:NBN
SbXV'&M2AT
/** KD^n7+w%
* @author Joa @fh:lsw
* LMHiiOs,
*/ w`I+4&/h
publicclass Page { A{%LL r:
a&Z;$
/** imply if the page has previous page */ K,5_{pj
privateboolean hasPrePage; ^I:f4RWo
~A03J:Yc7
/** imply if the page has next page */ /{>_'0
privateboolean hasNextPage; :j&- Lc
e4LJ3y&z"
/** the number of every page */ WX4f3Um
privateint everyPage; vI \8@97
Av>xgfX
/** the total page number */ I_5[-9
privateint totalPage; M4)Y%EPc
`l ?(zy:R
/** the number of current page */ *?rO@sQy]
privateint currentPage; YVLK X}$)(
&fe67#0r)
/** the begin index of the records by the current %:N;+1
wnjAiIE5
query */ G#YBfPmr
privateint beginIndex; oS^g "hQ`\
GJIZu&C
q+ 2v9K@
/** The default constructor */ BG_6$9y
public Page(){ ]]9VI0
vD76IG j m
} {RN-rF3w
:"'*1S*
/** construct the page by everyPage O`Y@U?^N
* @param everyPage s0m k<>z
* */ /HVxZ2bar
public Page(int everyPage){ dlH&8
this.everyPage = everyPage; N{H#j6QW
} #_Z)2ESX
8Om4G]*|,
/** The whole constructor */ XwIhD
public Page(boolean hasPrePage, boolean hasNextPage,
PckAL
R>hL.+l.
k>F>y|m
int everyPage, int totalPage, \3T[Cy|5|
int currentPage, int beginIndex){ d>O/Zal
this.hasPrePage = hasPrePage; 89UR w9
this.hasNextPage = hasNextPage; a
y$CUw
this.everyPage = everyPage; pfQ3Y$z
this.totalPage = totalPage; YBL.R;^v
this.currentPage = currentPage; Ac'pu,v
this.beginIndex = beginIndex; gjzU%{T?
} ',!>9Dj
NAX`y2z
/** (Rsf;VPO
* @return {wD:!\5
* Returns the beginIndex. VV"w{#XKw
*/ 1L%$\0B4hm
publicint getBeginIndex(){ :cKdl[E4z
return beginIndex; {g 4`>^;
} <6&Z5mpm$w
q;.LK8M
/** 45H9pY w
* @param beginIndex Y/T-2)D
* The beginIndex to set. hcoZ5!LvT
*/ Fg0!2MKq*
publicvoid setBeginIndex(int beginIndex){ SN]Na<P
this.beginIndex = beginIndex; LtGjHB\+
} O-!Q~;3][
W9;9\k
/** S@Aw1i p
* @return Z|xgZG{
* Returns the currentPage. kAs=5_?I
*/ O*yA50Cn
publicint getCurrentPage(){ xy4P_
return currentPage; %$N,6}n
} <Qt9MO`a
\46*4?pP
/** cNMDI
* @param currentPage HMhdK
* The currentPage to set. ,z#S=I
*/ OVGB7CB]S
publicvoid setCurrentPage(int currentPage){ .:O($9^Ho
this.currentPage = currentPage; :r7!HG_
} SPm2I(at7
<j1r6.E)
/** Ymf@r?F<
* @return K5F;/KR"
* Returns the everyPage. ^ywDa^;-
*/ uSv]1m_-]
publicint getEveryPage(){ zm3$)*p1
return everyPage; [x'D+!
} _k#GjAPM
GK[Hs1/
/** bX
6uGu
7
* @param everyPage a%/D~5Z
* The everyPage to set. M\RHFTB<C
*/ hFnUw26P
publicvoid setEveryPage(int everyPage){ )Myx(w"S
this.everyPage = everyPage; yd[4l%G(zS
} N*+WGsxl$z
|Xt6`~iC
/** _na/&J6
* @return |l@z7R+4*
* Returns the hasNextPage. i(kx'ua?
*/ -/Zy{2 <u
publicboolean getHasNextPage(){ ez~u A4
return hasNextPage; IaKJ W?
} s1t kiX{>
1jE {]/Y7&
/** y;_F[m
* @param hasNextPage \-sW>LIA
* The hasNextPage to set. 8#[2]1X^8
*/ v]rbm}uU9
publicvoid setHasNextPage(boolean hasNextPage){ 6}~k4;'}A
this.hasNextPage = hasNextPage; y9k'jEZ"oh
} SVObJsB^
% bKy
/** gLg.mV1<
* @return <$ qT(3w<y
* Returns the hasPrePage. #fk1'c2
*/
^Vf@J
publicboolean getHasPrePage(){ gX*j|(r
return hasPrePage; 0|g@;Pc
} Yj'"Wg
Hp5.F>-
/** -2'+GO7G
* @param hasPrePage CR;E*I${
* The hasPrePage to set. ^XG$?2<U
*/ E!uQ>'iq.
publicvoid setHasPrePage(boolean hasPrePage){ D&i,`j
this.hasPrePage = hasPrePage; U.h2 (-p
} =uEpeL~d;+
2vhP'?;K
/** bjI3xAs~
* @return Returns the totalPage. ?H>^X)Ph
* H[}lzL)
*/ ouO9%)zv
publicint getTotalPage(){ KT+{-"4-
return totalPage; 0/1=2E^,
} %gj7KF
[WV&Y,E
/** f>e0l'\
* @param totalPage /qMiv7m~Q
* The totalPage to set. `jyyRwSoe
*/ Db !8N
publicvoid setTotalPage(int totalPage){
Frz
this.totalPage = totalPage; cc>b#&s
} lr?SL\D
2R,8q0qR:
} !b&+2y2i[W
,*YmXR-"
H@9QEj!Y
u,{R,hTDS
4S4gK
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 pjQyN|KS
1yqsE`4f
个PageUtil,负责对Page对象进行构造: TL)7X.1'L
java代码: k~3\0man
<4<y
$G{j[iLY
/*Created on 2005-4-14*/ !%$,S=_F
package org.flyware.util.page; (nXnP{yb
,In%r`{i
import org.apache.commons.logging.Log; s
{^wr6B
import org.apache.commons.logging.LogFactory; ;$e)r3r`LV
IP@3R(DS%
/** U$3DIJVI
* @author Joa 1Kr$JIcd
* 4jGN:*kZ
*/ Dr[;\/|#
publicclass PageUtil { a)c;z@r
=f [/Pv
privatestaticfinal Log logger = LogFactory.getLog .lM]>y)
2,^> lY
(PageUtil.class); U_;="y
-7'|&zP
/** bfm+!9=9S
* Use the origin page to create a new page cB36w$n8
* @param page "K$c 9Z8
* @param totalRecords &[
],rT
* @return qL`yaU
*/ uA;#*eiA/
publicstatic Page createPage(Page page, int '[HQ}Wvn
>`/s+V
totalRecords){ A?$-Uqb"
return createPage(page.getEveryPage(), kjB'WzZ8
Qe-Pg^PS]
page.getCurrentPage(), totalRecords); D~Ef%!&
} KUK.;gG*Z
pzoh9}bue
/** ]9)iBvQlj
* the basic page utils not including exception #sBL E
6 eu7&Kj'
handler G
9(*F
* @param everyPage JtsXMZz
* @param currentPage l'@!'
* @param totalRecords B3D}'<
* @return page VBS}2>p
*/ MkjB4:"
publicstatic Page createPage(int everyPage, int "'@D\e}
7Z~JuTIZ
currentPage, int totalRecords){ V6'u\Ch|
everyPage = getEveryPage(everyPage); h::(b ,|f7
currentPage = getCurrentPage(currentPage); fA]sPh4Uag
int beginIndex = getBeginIndex(everyPage, "I:*
^IyQzBOj
currentPage); .'Q*_};W
int totalPage = getTotalPage(everyPage, GQk/ G0*&
e$WAf`*
totalRecords); eThFRU3 F
boolean hasNextPage = hasNextPage(currentPage, Nnr[@^M5
"Nb2[R
totalPage); Y
.cjEeL@
boolean hasPrePage = hasPrePage(currentPage); NZ&ZK@h}.
ao=e{R)
returnnew Page(hasPrePage, hasNextPage, mqHH1}
everyPage, totalPage, WVhQ?2@ }
currentPage, /5z,G r
"
DLIx}
beginIndex); 5c(g7N
} m.
p'LF
LwxJ:Kz.
privatestaticint getEveryPage(int everyPage){ bvrXz-j
return everyPage == 0 ? 10 : everyPage; ^#mWV
} 2boyBz}=S
/;/:>c
privatestaticint getCurrentPage(int currentPage){ 9N{?J"ido
return currentPage == 0 ? 1 : currentPage; Y`{62J8oy
} ,c$tKj5ulQ
ujkWVE'
privatestaticint getBeginIndex(int everyPage, int _b>{:H&\
g6aqsa
currentPage){ @ S[As~9X
return(currentPage - 1) * everyPage; YVvE>1z
} Yy 0" G
K(lSR
privatestaticint getTotalPage(int everyPage, int OcPgw/
I
H!hd0.
totalRecords){ t 4zUj%F
int totalPage = 0; {r$Ewc$Yb7
1a V32oK
if(totalRecords % everyPage == 0) !iNwJ|0
totalPage = totalRecords / everyPage; FG{,l=Z0
else x V`l6QS
totalPage = totalRecords / everyPage + 1 ; 4 qY
1KGf @u%-1
return totalPage; ,!alNNY
} 00f'G2n
.5!`wwVi
privatestaticboolean hasPrePage(int currentPage){ ,7:-V<'Yv
return currentPage == 1 ? false : true; ]s^+/8d=
} i2(v7Gef
!.q99DB
privatestaticboolean hasNextPage(int currentPage, }F/w34+;
>B~?
}@^Gk
int totalPage){ ~_"V7
return currentPage == totalPage || totalPage == [>pBz3fn,
+WR?<*_
0 ? false : true; oQ/T5cOj
} oIx|)[
>`a^E1)
Vp~ cN
} 6|
o S 5
@RszPH1B
H25Qx;(dTk
CueC![pj
Sy1O;RTn`
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 SiaW; ks
/5"T46jD
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 d0ht*b
vY|YqWt
做法如下: H
lM7^3(&
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ~Js kA5h|&
Z|N$qm}
的信息,和一个结果集List: R"JXWw
java代码: 3@ Fa
Y@#N_]oXj
trrK6(p
/*Created on 2005-6-13*/ WjK[% ;Z!
package com.adt.bo; ok:L]8UN3
B0)|sH
import java.util.List; EirZ}fDJzB
7)[Ve1;/N
import org.flyware.util.page.Page; +[MHl
i/'bpGrQ(
/** &g5PPQ18
* @author Joa !
}e75=x
*/ 9_jiUZFje
publicclass Result { M&29J
X<C fy
private Page page; s !2Iui
@
SJh~4R\
private List content; Hd\oV^>
qwJp&6
/** UjoA$A!Od;
* The default constructor 3<M yb
*/ (7b9irL&cn
public Result(){ {'h&[f>zcQ
super(); dL'oKh,
} |?{V-L
+y'2 h%>h[
/** .*9u_2<
* The constructor using fields ,"gPd!HD(
* u=W[ S)w
* @param page >lQa"F=
* @param content D]*|Zmr+}
*/ 5VOw}{Pt
public Result(Page page, List content){ : -#w
this.page = page; uF}dEDB|;
this.content = content; n&P~<2^M#
} %~M* <pN
;ZAwf0~
/** Il*!iX|23<
* @return Returns the content. *U$]U0M
*/ <dD!_S6@,
publicList getContent(){ ~@l4T_,k
return content; bfoTGi
} '1b)(IW
9@ fSO<
/** CR9wp]-Vd
* @return Returns the page. GwP!:p|
*/ '/03m\7
public Page getPage(){ snfFRc(RE
return page; ]*mUc`
} ElB[k<
FI?J8a
/** ~D|,$E tX4
* @param content V~/-e- 9u
* The content to set. ,C><n
kx
*/ _L~ 3h
public void setContent(List content){ x=7:D
this.content = content; u=v-,Tw
} >FOCdlJ#
Ot\[Ya''
/** i?(cp["7
* @param page Q"{Dijc%
* The page to set. .(cpYKFX
*/ &}P#<"Fo8Q
publicvoid setPage(Page page){ vw3[(_MV3_
this.page = page; [fT$# '6
} JZxA:dg
l
} c,;VnZ
9wC
_^(1Qb[
t'At9<ib
y6d!?M(0U
YzG?K0O%
2. 编写业务逻辑接口,并实现它(UserManager, 2[pOGc$
2>k*9kyp
UserManagerImpl) 25vjn 1$sW
java代码: (T pnJq
w8Z#]kRv
`3VI9GmQ
/*Created on 2005-7-15*/ >}~[ew
package com.adt.service; Q0jg(=9wP
]nRf%Vi8g
import net.sf.hibernate.HibernateException; 57;0,k5Gy
5,^DT15a4P
import org.flyware.util.page.Page; G,?a8(
8r+u!$i!H
import com.adt.bo.Result; !xR9I0V5
p\;8?x
/** j[dZ*Jr_
* @author Joa F::Ki4{jJ
*/ rL"]m_FK
publicinterface UserManager { 2%R.~9HtA
+<p&Va#
public Result listUser(Page page)throws 6AY(/N8V
L7(FDv,?
HibernateException; e/+.^ '{
GU/P%c/V
} q\i&ERr
1I69O6"
nF]R"
VvP: }yJ
VUUnB<j
java代码: <v'[Wl@hq
q#c+%,Z=C
U&R)a|
7R
/*Created on 2005-7-15*/ \VOv&s;h
package com.adt.service.impl; viYrPhH+z
YfT
D
import java.util.List; Z>y6[o
C)yw b6
import net.sf.hibernate.HibernateException;
ZLKbF9lo
xL.m<XDL
import org.flyware.util.page.Page; #Ox@[Z1I
import org.flyware.util.page.PageUtil; Pb T2-
F_
$X Uck[
import com.adt.bo.Result; V1d#7rP
import com.adt.dao.UserDAO; ?b(wZ-/
import com.adt.exception.ObjectNotFoundException; PbvA~gm
import com.adt.service.UserManager; fOSk>
gK
]C"?xy
/** 9"S iHp\)
* @author Joa e&i`/m5
*/ f!YlYk5
publicclass UserManagerImpl implements UserManager { &P}t<;
|+HJ>xA4I
private UserDAO userDAO; 7z3tDE[#
fCY??su*
/** "dt}k$Gr
* @param userDAO The userDAO to set. nPI$<yW7F
*/ N3#^Ifn[
publicvoid setUserDAO(UserDAO userDAO){ L58H)V3Pn
this.userDAO = userDAO; 5p~5-_JX
} n>eDN\5
Yh!k uS#<
/* (non-Javadoc) dB#c$1
* @see com.adt.service.UserManager#listUser pO)EYla9
kzCJs
(org.flyware.util.page.Page) N\tFK*U^I
*/ uc"%uc'
public Result listUser(Page page)throws .7Yox1,
G+2fmVB*X
HibernateException, ObjectNotFoundException { > fV"bj.
int totalRecords = userDAO.getUserCount(); .6rbn8h
if(totalRecords == 0) W-r^ME
throw new ObjectNotFoundException ^4]=D nd%
V+lS\E.
("userNotExist"); Io
IhQ
page = PageUtil.createPage(page, totalRecords); <uFj5.
List users = userDAO.getUserByPage(page); R%}<z*~NE@
returnnew Result(page, users); n
ei0LAD
} g&w~eWpk
G~&8/ s
} 58HAl_8W
=IX-n$d`>
$i<+O,@-
Q{=r9&&
D{7^y>8_Y-
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 <a_(qh@B
"v0bdaQH3
询,接下来编写UserDAO的代码: ,m0M:!hK
3. UserDAO 和 UserDAOImpl: mc2uI-W
java代码: wS,fj gX
7>r[.g
|"Zf0G
/*Created on 2005-7-15*/ ^K J#dT
package com.adt.dao; 9:xs)t- _
z8kebS&5
import java.util.List; V,& OO
e#}Fm;|d
import org.flyware.util.page.Page; -\%5aXr
(4q/LuP^d
import net.sf.hibernate.HibernateException; j$6Q]5KdoS
,2FI?}+R
/** i E;F=Rb
* @author Joa oVp/EQ
*/ rzie_)a Y%
publicinterface UserDAO extends BaseDAO { 2)$-L'YS
jFKp~`/#
publicList getUserByName(String name)throws (#85<|z
6Xo "?f
HibernateException; 1K|F;p
~bzac2Rp
publicint getUserCount()throws HibernateException; T)q
Uf
H
mb3aUFxA;
publicList getUserByPage(Page page)throws nW\W<[O9
"|&3z/AUh
HibernateException; oXk6,b"
jvR(e"
} UB8n,+R
Y%TY%"<
WO!OaC?+B,
"D4% A!i
ra^%__N}
java代码: Ax=)J{4v
}z9v*C
&ZFHWI(P
/*Created on 2005-7-15*/ 6pC1C.
package com.adt.dao.impl; >y#qn9rV1
pih 0ME}z
import java.util.List; r.Z g<T
e9Gu`$K
import org.flyware.util.page.Page; $7Z-Nn38
6#jql
import net.sf.hibernate.HibernateException; %B1TN#KoT
import net.sf.hibernate.Query; mv,a>Cvs[
%Q}(.h%M
import com.adt.dao.UserDAO; ld|GY>rH
6,~1^g*
/** 7l*vmF6Z
* @author Joa U6H3T0#
*/ /f oI.S
public class UserDAOImpl extends BaseDAOHibernateImpl >6WZSw/Hq
?D9iCP~~
implements UserDAO { hG<[F@d
-nUK%a"(D
/* (non-Javadoc) b-@9Xjv
* @see com.adt.dao.UserDAO#getUserByName Lq.2vfA>
14uv[z6
(java.lang.String) km^ZF<. @
*/ SS_6VE*sI
publicList getUserByName(String name)throws .ej+?QYwC
k5Q1.;fW76
HibernateException { hz<TjWXv'
String querySentence = "FROM user in class GCw4sb4~w
`@,Vbn^_
com.adt.po.User WHERE user.name=:name"; G[_Z|Xi1
Query query = getSession().createQuery OfA+|xT&
VhMVoW
(querySentence); #
&5.
query.setParameter("name", name); "s zJ[
_B
return query.list(); *h).V&::O
} qq[Dr|%7
grkA2%N
/* (non-Javadoc) ]8$H 'u(C
* @see com.adt.dao.UserDAO#getUserCount() &AeNrtGu
*/ jRDvVV/-wr
publicint getUserCount()throws HibernateException { %{^|Av1Uz
int count = 0; R/E6n &R
String querySentence = "SELECT count(*) FROM ZpBP#Y*
NN+;I^NqW&
user in class com.adt.po.User"; }[@Q**j(
Query query = getSession().createQuery W
9}xfy09
cud9oJ-=;
(querySentence); A yn$,
count = ((Integer)query.iterate().next NZ!I >
1#+|RL4o
()).intValue(); f4d-eXGwx`
return count; L5|g\Y`
} AkO);4A;Jd
y[AB,Dd
/* (non-Javadoc) uD{ xs
* @see com.adt.dao.UserDAO#getUserByPage s0x/2z
=h
~n5wQG
(org.flyware.util.page.Page) a{JO8<dlm
*/ RDy&i
publicList getUserByPage(Page page)throws ;9 ChBA
L=HnVgBs
HibernateException { x`I Wo:j
String querySentence = "FROM user in class 5~2_wWjX
g$hEVT
com.adt.po.User"; b<"jmB{
Query query = getSession().createQuery BE~-0g$W
_]D
6m2R
(querySentence); !
jDopE0L
query.setFirstResult(page.getBeginIndex()) -rgdKA@)(
.setMaxResults(page.getEveryPage()); yUxz,36wZ
return query.list(); Q^@7Yg@l
} +IjBeQ?
`2x. -
} oaILh
NNE(jJ`/
u.?jW vcv
VTyj<6Y
31e
O2|7
至此,一个完整的分页程序完成。前台的只需要调用 ^~bdAO81
2:nI4S
userManager.listUser(page)即可得到一个Page对象和结果集对象 w5/6+@}
[>3dhj[;
的综合体,而传入的参数page对象则可以由前台传入,如果用 vW? /:
>*!^pbZfX
webwork,甚至可以直接在配置文件中指定。 mU]^PC2[
}ALli0n`V)
下面给出一个webwork调用示例: = iDd{$
java代码: GY0OVAW6'c
R2 J A(Hn
=
8y,7u)
/*Created on 2005-6-17*/ jWh)bsqI!
package com.adt.action.user; &0%B3
ORWi+H|
import java.util.List; ]A#:Uc5
MOp "kA
import org.apache.commons.logging.Log; 0,.|-OZ
import org.apache.commons.logging.LogFactory; &_hEM~{
import org.flyware.util.page.Page;
+`ov1h
SK 5]7C2
import com.adt.bo.Result; "sY}@Q7
import com.adt.service.UserService; y>gw@+
import com.opensymphony.xwork.Action; r{SDJa
~.0'v [N
/** '^[+]
* @author Joa w8J8III\~
*/ Zt=P 0
publicclass ListUser implementsAction{ Acd@BL*
h5-yhG
privatestaticfinal Log logger = LogFactory.getLog YmjA!n
5tLb
o
(ListUser.class); |Sua4~yL(
]\L+]+u~
private UserService userService; ^}wF^ _
NZ6:ZzM
private Page page; sdyNJh7Jr
u$(ei2f
privateList users; 5dD8s-;^T
/<(-lbq,
/* KHJ wCv
* (non-Javadoc) C=cn.CX
* "*W# z
* @see com.opensymphony.xwork.Action#execute() [fo#){3K
*/ A^LS^!Jz
publicString execute()throwsException{ 5IFzbL#q#f
Result result = userService.listUser(page); AP1ZIc6
page = result.getPage(); Z'}%Mkm`i}
users = result.getContent(); ozl!vf# kv
return SUCCESS; ;vX1U8
} >Q[ Z{
SB .=x
/** }Ya! [tX
* @return Returns the page. 0)
F\aJ4Y
*/ WpnP^gmX
public Page getPage(){ }:;UnE}
return page; bw7g L\*
} u7Ix7`V
r
)_*MPY
/** <8Nr;96IA
* @return Returns the users. 'RzO`-dr
*/ u=vBjaN2_w
publicList getUsers(){ |3Oyg ?2
return users; t imY0fx#
} yx:+Xy*N
Y5;afU='
/** }&2,!;"">3
* @param page v9S=$Aj
* The page to set. #Er"i
*/ (uhE'IQ{(
publicvoid setPage(Page page){ >kmgYWG
this.page = page; niW"o-}
} ;$gV$KB:xA
|_-w{2K
/** Ht\2 IP
* @param users "Jg.)1Jw
* The users to set. H270)Cwn+
*/ n~}[/ly
publicvoid setUsers(List users){ k)X\z@I'
this.users = users; $N;J)
} nKnrh]hX
eMmNQRmH
/** [C<K~
* @param userService 5;^1Ab0
* The userService to set. UL>2gl4s/
*/ ~/z%yg
publicvoid setUserService(UserService userService){ u U>L (
this.userService = userService; p|mFF0SL
} (c^ {T)
} dGkw%3[
8e,F{>N
N mxh zjJ
lcjOBu
-qHG*v,
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, 1@h8.ym<"
llWY7u"
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 1EC;t1.7
HuU$x;~
么只需要: 3(,m(+J[S
java代码: y,ub*-:
k`|E&+og
'<uM\v^k
<?xml version="1.0"?> vTK8t:JQ~
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork \b8#xT}
V@b7$z
1.0//EN" "http://www.opensymphony.com/xwork/xwork- q 5z^y(Sv
4\ *:Lc,-
1.0.dtd"> w\eC{,00:
/4c`[
<xwork> 4Y2I'~'
^H1m8=
<package name="user" extends="webwork- WG,1%=M@
^,AE;ZT7
interceptors"> Q@>1z*'I
C<I?4WM
<!-- The default interceptor stack name Qzo -Yw`=
Jvsy
6R
--> xU0iz{9
<default-interceptor-ref 3!fR'L/i
{f)aFGp
name="myDefaultWebStack"/> Kl%[f jI)
wCR! bZ w
<action name="listUser" ecoI-@CAI
'-Cx-=
class="com.adt.action.user.ListUser"> &ZkJ,-
<param lX"m|W
"c]9Q%
name="page.everyPage">10</param> {k-_+#W"
<result <#nU 06 fN
b$fmU"%&|
name="success">/user/user_list.jsp</result> ^L)3O|6c
</action> 9lR6:}L7
V;"2=)X
</package> ?YZgH>7"
c$2kR:
</xwork> .ve_If-Hg
7 vFmB
U]vUa^nG
.PVYYhrt
Y9<[n)>+
:/szA?:W
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 rg
k1.0U0
d v[.u{#tP
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 f:&JKB)N
h@=@
fa
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 9"+MZ$
Xy 4k;+
)V[j~uOU)]
)$9wKk\F
.d^8?vo
我写的一个用于分页的类,用了泛型了,hoho 7qOkv1.}0
1t &_]q_
java代码: g |?}a]G
%%?}db1n
0|tyKP|J
package com.intokr.util; QK0]9
eZ]r"_?
import java.util.List; /*Q3=Dse]
X=)L$Kd7
/** *<:X3|3E
* 用于分页的类<br> (_@5V_U
* 可以用于传递查询的结果也可以用于传送查询的参数<br> kwT)j(pp<
* m[2[9bQ0
* @version 0.01
*~U.36
* @author cheng JWg.0d$hM
*/ fg#e*7Odn
public class Paginator<E> { _rIo
@v
privateint count = 0; // 总记录数 {S9gOg
privateint p = 1; // 页编号 ,
otXjz
privateint num = 20; // 每页的记录数 Ji9o0Y R
privateList<E> results = null; // 结果 $fD%18
L%5y@b{AR
/** U!o
* 结果总数
f&^}yqmuE
*/ 3MHpP5C
publicint getCount(){ p19(>|$J
return count; R$
+RTG:E
} ojf6@p_
<5pNFj}0;X
publicvoid setCount(int count){ Tr:@Dv.O
this.count = count; oYf+I
} juWXB+d2Y
5Wa)_@qI)`
/** XA;PWl5!
* 本结果所在的页码,从1开始 R--s
u:
* '*rS,y
* @return Returns the pageNo. K g#Bg##
*/ Aqf91
[c
publicint getP(){ 8WP"~Js!
return p; ^K1mh9O
} xPUukmG:B
NJr)f
/** S>(x x"Ia
* if(p<=0) p=1 FO^6c
* Oi: Hs
* @param p 8Y RT0/V
*/ WR#h~N
9c
publicvoid setP(int p){ 1<#D3CXK
if(p <= 0)
gvo98Id
p = 1; NR_3nt^h
this.p = p; GiuE\J9i
} (EWGX |QA
E`^D9:3:)
/** 45.g ;
* 每页记录数量 ZZ^A&%E(a
*/ oz{X"jfu
publicint getNum(){ Z'k?lkB2i
return num; rqN+0CT
} AhOBbss]q
RPeH [M^
/** v*GS>S
* if(num<1) num=1 @aUNyyVP
*/ F1$XUos9
publicvoid setNum(int num){ k}<H
if(num < 1) {{P 3Z[
num = 1; ]6`K
this.num = num; JC~sz^>p\
} }#e=*8F7
_^b\#Jz4U3
/** ]O:8o<0
* 获得总页数 z-We>KX
*/ "OI$PLK
publicint getPageNum(){ cW0\f5[/
return(count - 1) / num + 1; VM<0_R24z
} F{ vT^/
ZR3,dW6S
/** X4hz\={
* 获得本页的开始编号,为 (p-1)*num+1 [T7&)p
*/ x<!]#**;
publicint getStart(){ wj}LVyV
return(p - 1) * num + 1; oP56f"BE(
} !L9|iC:8
?OnL,y|
/** m)<+?Bv y
* @return Returns the results. ~s'}_5;VY
*/ aDX&j2/
publicList<E> getResults(){ cyWb*Wv
return results; ~x'8T!M{
} b&h'>(
=2GKv7q$x,
public void setResults(List<E> results){ [Fag\/Y+
this.results = results; 8(K:2
} ,R-k]^O
xu-bn
public String toString(){ RE4#a2
StringBuilder buff = new StringBuilder RF2I_4
I(BJ1 8F$
(); wY\,b*x
buff.append("{");
dI7rx+L
buff.append("count:").append(count); lbovwj
buff.append(",p:").append(p); $0$sDN6)x
buff.append(",nump:").append(num); :/][ n9J^
buff.append(",results:").append 0~$9z+S
xh#_K@ 8
(results); LHZsmUM(dg
buff.append("}"); sxF2ku4A
return buff.toString(); ~e[qh+
} 8b7I\J`
qrw*?6mSQ
} =eW4?9Uq
'Bt!X^
Gy["_;+xU