Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 R[6 r(h
FSFFk~
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 Bmmb
::0aY;D2
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 G^ K*+
hzW{_Q.|?
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 >@z d\}@W
j,Pwket
。 .Dc28F~t
omNpE_
分页支持类: G]1(X38[si
keq r%:E8
java代码: #aj|vox}
Ii,~HH
q^)=F_QvG
package com.javaeye.common.util; p1Y+
&zO3qt6
import java.util.List; 4 0p3Rv
vU ?b"n
publicclass PaginationSupport { GJ.kkTMT
u,:CJ[3
publicfinalstaticint PAGESIZE = 30; $+A%ODv
'y'T'2N3
privateint pageSize = PAGESIZE; =U=e?AOG2
[0h* &
privateList items; vYYS.ve
dK[*
privateint totalCount; _{[k[]
s*aH`M7^0
privateint[] indexes = newint[0]; +Gk!
t]dy
'2wXV;`
privateint startIndex = 0; ,Le&I9*%
Y;'VosTD
public PaginationSupport(List items, int F_ ,L2J
(Nm}3 p
totalCount){ t|go5DXz4
setPageSize(PAGESIZE); AD~~e%
s=
setTotalCount(totalCount); 8f /T!5
setItems(items); av'd%LZP
setStartIndex(0); [`y:M&@
} C}n[?R
i_[^s:*T
public PaginationSupport(List items, int ?SB[lbU
SPfD2%jjC
totalCount, int startIndex){ Pz5ebhgq
setPageSize(PAGESIZE); IXbdS9,>F
setTotalCount(totalCount); k&MlQ2'!<
setItems(items); ?BWHr(J
setStartIndex(startIndex); M(_^'3u
} BM|-GErE
<QYCo1_
public PaginationSupport(List items, int FE0qw1{qQ
HiQoRk
totalCount, int pageSize, int startIndex){ fBHkLRFH
setPageSize(pageSize); = 4BLc
setTotalCount(totalCount); sN6 0o 7.
setItems(items); 6V.awg,
setStartIndex(startIndex); 8#X?k/mzU
} l81&[
6(ka"Vu~
publicList getItems(){ &>&dhdTQ
return items; R59e&
} 3~cS}N T
VQ1?Db(_2
publicvoid setItems(List items){ 54`bE$:+
this.items = items; Bpk@ {E9
} H arFo
3X88x-3
publicint getPageSize(){ *,O
:>Z5I
return pageSize; FBR$,j;Y
} I>A^5nk
`f\5p+!<7R
publicvoid setPageSize(int pageSize){ =XZF.ur
this.pageSize = pageSize; R=][>\7]}
} ;FV~q{
!L&=?CX
publicint getTotalCount(){ -_y~rx
>
return totalCount; t!J";l
} Uq9,(tV`6g
8L]gQ g
publicvoid setTotalCount(int totalCount){ {B'Gm]4
if(totalCount > 0){ "7Toc4
this.totalCount = totalCount; ^q4l4)8jX
int count = totalCount / yRgDhA
W
/~||s
pageSize; G=r(SJq
if(totalCount % pageSize > 0) Gk{
"O%AE
count++; 4
+da
indexes = newint[count]; DiZ!c"$
for(int i = 0; i < count; i++){ X";QA":
indexes = pageSize * iFAoAw(
377j3dP
i;
q8'@dH
} 9pVf2|5hj
}else{ H3
A]m~=3
this.totalCount = 0; C$N4
} [oQ`HX1g
} /7UovKKbz
Q9Y9{T
publicint[] getIndexes(){ EWuiaw.
return indexes; *tq|x[<
} pO-s@"j]
eHF(,JI
publicvoid setIndexes(int[] indexes){ R`I8Ud4=
this.indexes = indexes; 6nY
)D6$JG
} &J5-'{U|0
u7WTSL%
publicint getStartIndex(){ 4%',scn
return startIndex; ~xlMHf
} Lyf? V(S
hr~qt~Oi
publicvoid setStartIndex(int startIndex){ J{GFb
if(totalCount <= 0) Ovl?j&8
this.startIndex = 0; )$gsU@H -
elseif(startIndex >= totalCount) +(I`@5
this.startIndex = indexes giPhW>
a0V8L+v(
[indexes.length - 1]; ijZydn
elseif(startIndex < 0) =u:6b} =
this.startIndex = 0; ]AFM Y<mB
else{ u>3&.t@hU1
this.startIndex = indexes Ru
vG1"
~n8*@9[
[startIndex / pageSize]; O5G<O(,\
} vUo.BA#;.b
} v2Qc}o
a.Rp#}f
publicint getNextIndex(){ 0aTEJX$iZ
int nextIndex = getStartIndex() + `aO@N(
RF,=bOr19
pageSize; OIXAjU*N
if(nextIndex >= totalCount) Pt PGi^
return getStartIndex(); Dj,+t+|
else &G7)s%q
return nextIndex; 0bnVIG2q
} C%95~\Ds
zP{<0o
publicint getPreviousIndex(){ NU)`js
int previousIndex = getStartIndex() - UuOLv;v
gT5Ji~xI
pageSize; TQ 5MKqR$
if(previousIndex < 0) RB% fA%d
return0; !q=Q~ea
else 764}yV>
return previousIndex; @T,H.#bL
} 7fN&Q~.
#g-*n@
1
} L?D~~Jb
iZkW+5(
~-`BSR
`%mBu`A
抽象业务类 X#Dhk6
java代码: u':0"5}
:m)Rmwn_
giSG 6'WA
/** +Qi52OG
* Created on 2005-7-12 @8Q+=abz
*/ D|Ih e%w-
package com.javaeye.common.business; T^(n+ lv
u\1Wkxj
import java.io.Serializable; PG v}fEH"
import java.util.List; :)J~FVLy
KWigMh\r
import org.hibernate.Criteria; Z#TgFQ3u
import org.hibernate.HibernateException; }eDX8b8emA
import org.hibernate.Session; N?mY|x\}wK
import org.hibernate.criterion.DetachedCriteria; g]@R'2:1
import org.hibernate.criterion.Projections; ko+M,kjwR
import a`@<Z sR
Lm*LJ_+ B
org.springframework.orm.hibernate3.HibernateCallback; 53u.pc
import [Tb3z:UUvf
tEWj}rX
org.springframework.orm.hibernate3.support.HibernateDaoS N5w]2xz!
R/Dy05nloe
upport; (g)lv)4P
8|jX ~f
import com.javaeye.common.util.PaginationSupport; R0YC:rAt
#Zavdkw=d
public abstract class AbstractManager extends /4-eoTxy
;5oH6{7_Z
HibernateDaoSupport { dV2b)p4J
0JZq:hUd
privateboolean cacheQueries = false; W-]yKSob
|E_+*1l q.
privateString queryCacheRegion; Y^*$PED?
c;|&>Fp
publicvoid setCacheQueries(boolean pqQdr-aR=
YI),q.3X~
cacheQueries){ _9O }d
this.cacheQueries = cacheQueries; i2ml[;*,N
} sm&rR=b
Jm J,~_
publicvoid setQueryCacheRegion(String Aya;ycsgE
/hEGk~
queryCacheRegion){ $hE'b9qx
this.queryCacheRegion = LN6 JH!
x]d"|jmVZ
queryCacheRegion; VGDEP!)-8
} z5*O@_r+.b
5W]N]^v
publicvoid save(finalObject entity){ f$@".
getHibernateTemplate().save(entity); \$HB~u%dr
} ~tj7zI6
P2:Q+j:PX
publicvoid persist(finalObject entity){ qf&a<[p~
getHibernateTemplate().save(entity); \q`+
} ?xTeio44
IO)Ft
publicvoid update(finalObject entity){ k2tX$ \E
getHibernateTemplate().update(entity); (zLIv9$
} ]'ApOp
CD<u@l,1
publicvoid delete(finalObject entity){ $
p1EqVu
getHibernateTemplate().delete(entity); rgZrE;*;
}
@Kb|
8H`l"
publicObject load(finalClass entity, j&G~;(DY
)J6b:W
finalSerializable id){ fi4/@tV?$L
return getHibernateTemplate().load eP'kY(g8
sK9h=J;F/
(entity, id); -qCJwz30
} ?>\]%$5o
$Q$d\Yvi
publicObject get(finalClass entity, BLH3$*,H
,l?76g
finalSerializable id){ Dp6"I!L<|
return getHibernateTemplate().get 5~R{,]52
BiLreZ~"
(entity, id); FivaCNA
} :ktX7p~
!/(}meZj
publicList findAll(finalClass entity){ O>F.Wf5g
return getHibernateTemplate().find("from I8%'Z>E(
B)cb}.N:
" + entity.getName()); ieF 0<'iF
} .-26 N6S
v*]Xur6e}
publicList findByNamedQuery(finalString YK+Z0ry
<C`eZ}Qqv
namedQuery){ r|F,\fF
return getHibernateTemplate >E,L"&_j
BHE =Zo
().findByNamedQuery(namedQuery); >]|^Ux,WZ
} dvWlx]'
?'#;Y"RT
publicList findByNamedQuery(finalString query, (X7yNIPfA
HY| SLk/E
finalObject parameter){ [[DFEvOEh
return getHibernateTemplate 3@ukkO)
`V_/Cz_}D
().findByNamedQuery(query, parameter); :3*oAh8|
} !skWe~/
+~k,4
publicList findByNamedQuery(finalString query, 257;@;
i R5soIR
finalObject[] parameters){ k 5r*?Os
return getHibernateTemplate v;qL?_:=c
vHe.+XY
().findByNamedQuery(query, parameters); .MPOUo/e
} O
xaua
p[VCt" j
publicList find(finalString query){ EGr5xR-
return getHibernateTemplate().find )3\rp$]1
ZU@jtqq
(query); 5h^qtK
} `/Jr8J_
"lzg@=$|)
publicList find(finalString query, finalObject ] "vdC}
iw;Alav"x
parameter){ AezXou&
return getHibernateTemplate().find ';!UJWYl
7IW7'klkvD
(query, parameter); \mit&EUh}
} A_
z:^9
%a^!~qV
public PaginationSupport findPageByCriteria (xJBN?NRO
K{h]./%
(final DetachedCriteria detachedCriteria){ Cu<ojN- $
return findPageByCriteria .z7f_KX^
pnb$lpxt
(detachedCriteria, PaginationSupport.PAGESIZE, 0); /!8:/7r+W
} F qyJ*W\1
by ee-BU
public PaginationSupport findPageByCriteria F+-MafN7Y
s_?*R
(final DetachedCriteria detachedCriteria, finalint ,qh
+mPB?5
startIndex){ }slEkpk?]
return findPageByCriteria >'g60 R[
ATewdq[C
(detachedCriteria, PaginationSupport.PAGESIZE, V0B4<TTAo~
T js{
)r9
startIndex); ]V\g$@
} 52Ffle8
j*\MUR=
public PaginationSupport findPageByCriteria yG_.|%e
GDe$p;#"9g
(final DetachedCriteria detachedCriteria, finalint >%A=b}VS
$k=rd#3
pageSize, Du4?n8 o
finalint startIndex){ *Y>'v%
return(PaginationSupport) ViONG]F
;yoq/
getHibernateTemplate().execute(new HibernateCallback(){ kQcQi}e
publicObject doInHibernate |EU08b]P29
wC@U/?
(Session session)throws HibernateException { 9uo\&,,
Criteria criteria = 7En~~J3
]qQB+]WN
detachedCriteria.getExecutableCriteria(session); Fd0FG A&L
int totalCount = A[Xw |9
!LESRh?
((Integer) criteria.setProjection(Projections.rowCount cv&hT.1
z`6KX93
()).uniqueResult()).intValue(); xBd%e-r
criteria.setProjection @}}1xP4Sr
^U1+D^AJ
(null); $(hZw
List items = @g?z>n
n
A#\X-8/
criteria.setFirstResult(startIndex).setMaxResults D^4V"rq
t*$@QO
(pageSize).list(); I!%@|[ Ow
PaginationSupport ps = E$baQU hKS
uu #+|ZD
new PaginationSupport(items, totalCount, pageSize, o
W [-?
%|||M=akk
startIndex); 7]
H4E.(l
return ps; C_;6-Q%V
} J#^M
}, true); 3KZ h?~B
} o{eG6
7wiu%zfa:=
public List findAllByCriteria(final /;J;,G`?
V!4E(sX
DetachedCriteria detachedCriteria){ iWsIc\!+,
return(List) getHibernateTemplate Oms`i&}"}
q\G@Nn^
().execute(new HibernateCallback(){ -rrg?4
publicObject doInHibernate +d.Bf
r4'Pf|`u
(Session session)throws HibernateException { IrK )N
Criteria criteria = ENr&k(>0HQ
e
hGC
N=
detachedCriteria.getExecutableCriteria(session); kSrzIq<xre
return criteria.list(); @:8|tJu8b
} 7hQl,v< 5
}, true); awtzt?VtLh
} 6&cU*Io@
<aS1bQgaU
public int getCountByCriteria(final o
qTh )
b ;b1V
DetachedCriteria detachedCriteria){ /_HL&|N_5
Integer count = (Integer) pgarGaeq
LPClE5
getHibernateTemplate().execute(new HibernateCallback(){ QUO?q+
publicObject doInHibernate epePx0N%x$
:2+:(^l
(Session session)throws HibernateException { owB)+
Criteria criteria = pQJZE7S
g.qp _O
detachedCriteria.getExecutableCriteria(session); hHQt4 r'd
return Obm\h*$
:>u{BG;=79
criteria.setProjection(Projections.rowCount TW$^]u~v
G{9y`;
()).uniqueResult(); qxNV~aK
} g>{=R|uO5
}, true); [o "@*kf
return count.intValue(); q}lSnWY[[
} QS_xOQ '
} 0o`o'Z V=c
/6fs h7 \
hvwr!(|W
N~_gT
Jr~P
:8FH{sqR
z%z$'m
用户在web层构造查询条件detachedCriteria,和可选的 +xa2e?A%L
YrX{,YtiX
startIndex,调用业务bean的相应findByCriteria方法,返回一个 B("kE`
_;9)^})$
PaginationSupport的实例ps。 ~drNlt9jf
W3#L!&z_wK
ps.getItems()得到已分页好的结果集 p;HZA}p \
ps.getIndexes()得到分页索引的数组 6\L,L&
ps.getTotalCount()得到总结果数 VEk|lX;2
ps.getStartIndex()当前分页索引 ]v@,>!Wn
ps.getNextIndex()下一页索引 CEiGjo^
ps.getPreviousIndex()上一页索引 f3O'lc3
}OZfsYPz}T
#N:o)I
0n%`Xb0q
x
:s-\>RcA
3zkq'lZ
U-d&q>_@A
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 aE}u5L$#
{Ffr l(*
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 bk2vce&
\_oHuw
一下代码重构了。 YR>x h2< 9
fQ@["b
我把原本我的做法也提供出来供大家讨论吧: o5d)v)Rx=
9(Z)c
首先,为了实现分页查询,我封装了一个Page类: QGa"HG5NF
java代码: -3C~}~$>`
. Hw^Nx
H
Zc;.jJ
/*Created on 2005-4-14*/ iD9GAe}x
package org.flyware.util.page; kE1u-EA
R~o?X^^O
/** qohUxtnTK>
* @author Joa U3>G9g>^B
* >dO^pDSs
*/ {chl+au*l
publicclass Page { g~]FI
(,k=mF
/** imply if the page has previous page */ ?V+=uTCq
privateboolean hasPrePage; UaB!,vs3st
:'03*A_[
/** imply if the page has next page */ cVU[>gkg_
privateboolean hasNextPage; d+kIof,
d] {^
/** the number of every page */ X#fI$9a
privateint everyPage; Cs< d\"+
$Khc?v
/** the total page number */ 5u8 YHv
privateint totalPage; hhpH)Bi=
FRr<K^M
/** the number of current page */ +aMPwTF:3
privateint currentPage; 3j6$!89'
z;LntQZp-
/** the begin index of the records by the current 4IVCTz[
N9hBGa$
query */ SI\zW[IL
privateint beginIndex; 9
HuE'(wQ
MQAb8 K:e
Ood&cP'c
/** The default constructor */ ^#Shs^#
public Page(){ tkA '_dcIC
cP-6O42
} VHy$\5oYg
w%htY.-
/** construct the page by everyPage {ES3nCL(8
* @param everyPage N:0mjHG
* */ 7yKadM~)
public Page(int everyPage){ (RQ kwu/
this.everyPage = everyPage; :Q89j4,
} v6FYlKU@8
<X:7$v6T|
/** The whole constructor */ '_2~8w
public Page(boolean hasPrePage, boolean hasNextPage, >qOhzbAH{<
z7 }@8F
[/I4Pe1Yj%
int everyPage, int totalPage, arnu|paw
int currentPage, int beginIndex){ n@xU5Q
this.hasPrePage = hasPrePage; 0@z78h=h
this.hasNextPage = hasNextPage; {epsiHK@tK
this.everyPage = everyPage; .Sm7na
K
this.totalPage = totalPage; y'{0|Xj
this.currentPage = currentPage; ;s{rJG{inG
this.beginIndex = beginIndex; P66>w})@
} (sZB-
yPW?%7 h
/** Rgg(rF=K6
* @return 4Vh#Ye:`
* Returns the beginIndex. `CO?} rW
*/ f>dWl$/_s
publicint getBeginIndex(){ 7JjTm^bu
return beginIndex; mIt=r_
} YOqBIbp~&)
!-[e$?-
/** rB-&'#3%
* @param beginIndex ~ u jY+{
* The beginIndex to set. wPOQy~:
*/
%ZZ\Xj
publicvoid setBeginIndex(int beginIndex){ =MA$xz3
this.beginIndex = beginIndex; w18kTa!4@
} zbrDDkZ1
0 }
uH
/** Y*0mC "n}
* @return PKk_9Xd
* Returns the currentPage. WEZ)7H
*/ M1^pf<!s
publicint getCurrentPage(){ A^xDAxk
return currentPage; zl$'W=[rFs
} M,zUg_ @
d(<[$3.
/** .z+[3Oj_E
* @param currentPage +eQg+@u
* The currentPage to set. SD |5v*
*/ *1|&uE&_R
publicvoid setCurrentPage(int currentPage){ a=Pl3Uo
this.currentPage = currentPage; f/aSqhAW
} a(QYc?u
w(0's'
/** ]FP(,:Yw
* @return Enyx+]9
* Returns the everyPage. )V7bi^r
*/ SRyAW\*LWU
publicint getEveryPage(){ r1f##
return everyPage; !c/G'se
} s'RE~,
XX+%:,G
/** Ny\p$v
"p
* @param everyPage G[GSt`LVS`
* The everyPage to set. X)P9f N~7
*/ qf#Ou
publicvoid setEveryPage(int everyPage){ Qt`}$]
this.everyPage = everyPage; P`0}( '"U
} @uXF(KDX
>La!O~d
/** 1?\G6T
* @return {HHc}8
* Returns the hasNextPage. jt=%oa
*/ ]y:2OP
publicboolean getHasNextPage(){ +/E`u|%|\]
return hasNextPage; 1%g%I8W%
} 0e-M 24,C
7M9Ey29f
/** j&~`H:=E
* @param hasNextPage 6B'd]Fe
* The hasNextPage to set. [,JUC<
*/ VXX7Y?!
publicvoid setHasNextPage(boolean hasNextPage){ DvhJkdLB>
this.hasNextPage = hasNextPage; }f45>@uMW
} 1ayL*tr
L;6L@D6
/**
UDl[
* @return cgY+xd@
* Returns the hasPrePage. F/}(FG<'>I
*/ WTK )SKa,.
publicboolean getHasPrePage(){ W!6&T [j>
return hasPrePage; &V"9[0
} P3Ocfpf Bp
?QR13l(
/** VEFUj&t;xW
* @param hasPrePage PaIE=Q4gJ
* The hasPrePage to set. O(pa;&"
*/ !X5n'1&
publicvoid setHasPrePage(boolean hasPrePage){ |}$ZOwc
this.hasPrePage = hasPrePage; $IUe](a{d
} D[#6jJAb
4b5'nu
/** @,kR<1
* @return Returns the totalPage. `?P)RS30
* ]fiAV|'^
*/ U}hQVpP#
publicint getTotalPage(){ )a99@`L\P
return totalPage; T3H\KRe6
} ol#|
.a2O
t:$^iUrx
/** Ct@O S227x
* @param totalPage % XvJJ
* The totalPage to set. 7UnB]- :.
*/ xQA6!j
publicvoid setTotalPage(int totalPage){ so=Ux2
this.totalPage = totalPage; KcPI,.4{
} ny++U;qi
NRIp@PIF:"
} Z@f4=
';,Rq9-'
,;%F\<b
uz
U2)n3y
jc0Trs{Jf
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 cI#! Y
%0&c0vT
个PageUtil,负责对Page对象进行构造: KdN+$fe*g
java代码: v2K6y|6,
k
z{_H`5.
^p7g[E&
/*Created on 2005-4-14*/ pXPLTGY<R+
package org.flyware.util.page; SobOUly5{
xQU$E|I
import org.apache.commons.logging.Log; + 0DPhc
import org.apache.commons.logging.LogFactory; /u&{=nU
tMbracm
/** K."%PdC
* @author Joa Q95`GuI@
* `PH]_]:%
*/ sW#OA\i&
publicclass PageUtil { ( :h#H[F
mto=_|gn
privatestaticfinal Log logger = LogFactory.getLog {VK
{>r56\!F
(PageUtil.class); sR;^7(f!m
Lkf}+aY
/** _ -6IB>
* Use the origin page to create a new page 5yl[#>qt
* @param page J
n~t>?
* @param totalRecords "~+?xke5z
* @return ,Y+J.8.H
*/ JbR;E`8
publicstatic Page createPage(Page page, int K+P:g%M
#^i.[7p
totalRecords){ V(#z{!
return createPage(page.getEveryPage(), i!KZg74V
+ $Yld{i
page.getCurrentPage(), totalRecords); F<9S,
} IVY{N/ 3|
3q}fDM(@J
/** *h9S\Pv>j
* the basic page utils not including exception Q |1-j
4). i4]%LH
handler 7c8A|E0\mF
* @param everyPage mN^/
* @param currentPage .e Jt]K
* @param totalRecords f=,(0ygt/
* @return page f%gdFtJ &
*/ q'9}Hz
publicstatic Page createPage(int everyPage, int 'h*^;3@*
W|,Y*l
currentPage, int totalRecords){ I
7 B$X=
everyPage = getEveryPage(everyPage); XLq%nVBM8\
currentPage = getCurrentPage(currentPage); Ec4+wRWk85
int beginIndex = getBeginIndex(everyPage, P/?'ea
{3H)c^Q
currentPage); rY:A LA
int totalPage = getTotalPage(everyPage, Et0[HotO
4z*An}ol]
totalRecords); q-<t'uhs[
boolean hasNextPage = hasNextPage(currentPage, %4#Q3YlyD
F Bk_LEcX
totalPage); ]>_Ie?L)<
boolean hasPrePage = hasPrePage(currentPage); v<u`wnt
|,)=-21&;
returnnew Page(hasPrePage, hasNextPage, lO+6|oF0
everyPage, totalPage, \2U F J
currentPage, _*1{fvv0{
I[g;p8jr
beginIndex); ,z@"pI
b
} 0 v>*P*
.z6"(?~
privatestaticint getEveryPage(int everyPage){ bsosva+
return everyPage == 0 ? 10 : everyPage; .?^a|]
} 9]]isE8r
%Bf;F;xuB
privatestaticint getCurrentPage(int currentPage){ Xe. az
return currentPage == 0 ? 1 : currentPage; b,#lw_U"
} w$fP$ \+
<n|ayxA)
privatestaticint getBeginIndex(int everyPage, int ==XO:P
hT
DFIYV
currentPage){ Lbwc2Q,.-
return(currentPage - 1) * everyPage; TDY2
M
} <RaUs2Q3.
6a MG!_jC
privatestaticint getTotalPage(int everyPage, int {wq~+O
'jr[
?WQ
totalRecords){ -RK R.,
int totalPage = 0; W!=X_
xZc].l6
if(totalRecords % everyPage == 0) X8uAwHa6F
totalPage = totalRecords / everyPage; y(92 Th$
else 81jVjf?`
totalPage = totalRecords / everyPage + 1 ; GFX$vn-/F
A^3M~
return totalPage; x(r~<a[
} PYhRP00}M
2M`:/ shq
privatestaticboolean hasPrePage(int currentPage){ \#%1t
return currentPage == 1 ? false : true; qy\Z2k
} tX'2 $}
dd6m/3uUW
privatestaticboolean hasNextPage(int currentPage, 9Z!|oDP-
+J;T= p
int totalPage){ j8[RDiJ
return currentPage == totalPage || totalPage == 4apy {W
Yn+d!w<3:
0 ? false : true; /t=Fx94
} X:kqX[\>
q37d:Hp
x<gP5c>zm
} l'm\*=3
Z^_-LX:%
*k^'xL
T
P#Hq
q1_iV.G<
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。
WH^^.^(i
+>Xe_
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 2^f6@;=M
57~/QEdy
做法如下: 'OjsV$_
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 !Sj0! \
W9M~2<
L
的信息,和一个结果集List: %}/ |/=
java代码: tmVGJ+gz
#[B]\HO
zg+6<
.Sf
/*Created on 2005-6-13*/ Yk @/+PE
package com.adt.bo; 6t!PHA
hgPzx@
import java.util.List; glI4Jb_[
t,,W{M|E(
import org.flyware.util.page.Page; 6U(MHxY
qC:QY6g$N
/** jBLLx{
* @author Joa ^=.QQo||B
*/ 8%Eemk >G{
publicclass Result { Ax{C ^u
W^" C|4G }
private Page page; 1wTPT,k
u!@(u!Qz
private List content; yq<mE(hS?
J)n^b
/** Ef2i#BoZ
* The default constructor sn-P&"q
*/ ms/!8X$Mz
public Result(){ K|V<e[X[V
super(); +DwE~l
} OGWZq(c"6
x3tos!Y
/** JZ>E<U9&
* The constructor using fields J2avt
* rZ:-%#Q4
* @param page 8kYI ~
* @param content u [Dz~
*/ AU3>v
public Result(Page page, List content){ ,
aJC7'(
this.page = page; 9kby-A4
this.content = content; ?&_u$Nn
} `&w{-om\
Wz&[cj
/** ,qu7XFYrY
* @return Returns the content. z;Yo76P
*/ L{F[>^1Sb
publicList getContent(){ E
E^lw61
return content; F!qt=)V@w
} o8c5~fG1
/{%p%Q[X
/** A(}D76o_
* @return Returns the page. IlfH
*/ k^Qd%;bdF
public Page getPage(){ Z3qr2/
return page;
AQm#a;
} F1GFn|OA
p:?h)'bA<
/** \PL0-.t,
* @param content 'aqlNBG*
* The content to set. q#_<J1)z
*/ YMr2Dv\y
public void setContent(List content){ 7w5C
NV
this.content = content; opv<r*!
} PFI^+';
&1Cif$Y4w
/** sDl@
* @param page 7?"-:q
* The page to set. 3{H&{@Q
*/ e#!,/pE
publicvoid setPage(Page page){ dj2w_:&W
this.page = page; hEMS
} j^6,V\;l
} BK)3b6L=%
AOv>O52F/Q
]47!Zo,
)'i n}M
ZO8r8
[
2. 编写业务逻辑接口,并实现它(UserManager, 'BX
U'
D $&6 8
UserManagerImpl) .g>0FP
java代码: )~be<G( a
$Y?[[>u
fM!@cph(8
/*Created on 2005-7-15*/ 7Sl"q=>
package com.adt.service; {xu~Dx
IylfMwLC
import net.sf.hibernate.HibernateException; #ja6nt8GC
J*D3=5&
import org.flyware.util.page.Page; s)~Wcp'+M:
@B9O*x+n:
import com.adt.bo.Result; Pj^O8
->rudRQ
/** [oG
Sy5bB
* @author Joa "?S>}G\
*/ Rc(E';uc
publicinterface UserManager { 7;@o]9 W
w~ O)DhC
public Result listUser(Page page)throws *hlinQKs
[13NhF3.P
HibernateException; Q`!<2i;
zb. ^p
X
} 1
&-%<o
%@^9(xTE
(nAg
~i
>A>_UT_"
DbrK,'b%
java代码: lS |:4U.
Z+agS8e(
icN#8\E
/*Created on 2005-7-15*/ &I7T?
package com.adt.service.impl; '<1Q;3Ho
6F; |x
import java.util.List; GsiT!OP]y
U.c~l,5%"
import net.sf.hibernate.HibernateException; mk[<=k~
ZO&F15$P
import org.flyware.util.page.Page; PMZ*ECIJU
import org.flyware.util.page.PageUtil; seiE2F[
`teaE7^Wm
import com.adt.bo.Result; %ZTI ?a
import com.adt.dao.UserDAO; ?6 _U>d{
import com.adt.exception.ObjectNotFoundException; ~}g)N
import com.adt.service.UserManager; ?P"j5
e$N1m:1*
/** I>:.fHvUC
* @author Joa xcX^L84\
*/ 4%*`'o$_
publicclass UserManagerImpl implements UserManager { CGs5`a
4?Qc&e{5
private UserDAO userDAO; }*,z~y}V#
PJ2m4ulY
/** 7-MyiCt
* @param userDAO The userDAO to set. @vPGkM#oW
*/ ]69z-;
publicvoid setUserDAO(UserDAO userDAO){ C
A $R
this.userDAO = userDAO; J=B,$4)9
} ]~7xq)28
ALt^@|!d
/* (non-Javadoc) uO4R5F|tL
* @see com.adt.service.UserManager#listUser Y0g6zHk7
zv~b-Tp
(org.flyware.util.page.Page) +t}<e(
*/ @ ]
3`S
public Result listUser(Page page)throws LX7<+`aa
ZG)6{WS
HibernateException, ObjectNotFoundException { ~QU\kZ7Z
int totalRecords = userDAO.getUserCount(); `! _mIh}
if(totalRecords == 0) X;d 1@G
throw new ObjectNotFoundException vg\fBHzn
oB%j3aAH
("userNotExist"); M7c53fz
page = PageUtil.createPage(page, totalRecords); `g'z6~c7n
List users = userDAO.getUserByPage(page);
5Eu`1f?
returnnew Result(page, users); EHda
} seA=7c5E
/OeOL3Y
} @pV&{Vp
ZqfoO!Ta
zfK3$|
28O 3N;a
79Q>t%rD[
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 \&4)['4,
>/7[HhBT
询,接下来编写UserDAO的代码: /,3:<I
3. UserDAO 和 UserDAOImpl: !L@^Zgs|@?
java代码: 02q*z>:^
3`{[T17
cLm{gd4 W
/*Created on 2005-7-15*/ 0b+End#mp
package com.adt.dao; ;c|G
4n/CSAT1
import java.util.List; 8[d6 s
:2-!bLo}&
import org.flyware.util.page.Page; ,e+S7YX
^A$p)`KR
import net.sf.hibernate.HibernateException; J4jL%5t
5 0<
/** !KLY*bt6
* @author Joa H~~>ut6`
*/ e`;U9Z
publicinterface UserDAO extends BaseDAO { &I?d(Z=:\
kRB2J3Nt.
publicList getUserByName(String name)throws %-3wR@
!\|L(Paf
HibernateException; ;\gHFG}
y-vQ4G5F|
publicint getUserCount()throws HibernateException; Te@=8-u-
rNeSg=j
publicList getUserByPage(Page page)throws Q3aZB*$K
Uc5BNk7<=
HibernateException; -4t!k
Aw`
ux1SQ8C *
} OB\jq!"
JV;-P=o1B
~%u;lr
*"sDsXo- I
="s>lI-1a
java代码: \-RVPa8k
kcZz WG|n
5
DvD
/*Created on 2005-7-15*/ FWuk@t[<O
package com.adt.dao.impl; i`EG80\[Z
qh/}/Sl;
import java.util.List; EALgBv>#ZL
T<~?7-O"
import org.flyware.util.page.Page; )U:W
9%
<9aa@c57
import net.sf.hibernate.HibernateException; ~k/GmH
import net.sf.hibernate.Query; 8% `Jf`
3<ry/{#%
import com.adt.dao.UserDAO; j(];b+>
3L-}B#tI
/** P{o //M
* @author Joa 7A4_b8
*/ K5:>
public class UserDAOImpl extends BaseDAOHibernateImpl .u&GbM%Ga
[TX5O\g![
implements UserDAO { Un{ 9reX5
@M8vPH
/* (non-Javadoc) [h~#5x
* @see com.adt.dao.UserDAO#getUserByName 9vJ'9Z2\
[:bYd}J
(java.lang.String) rWxQ;bb#
*/ c~{)vL0K
publicList getUserByName(String name)throws 992cy2,Fb
d/&~IR
HibernateException { SMbhJ}\O
String querySentence = "FROM user in class y<*/\]t9L[
V"Y-|R
com.adt.po.User WHERE user.name=:name"; ^RE("'+
Query query = getSession().createQuery w$z]Z-
L(\o66a-rV
(querySentence); T`SpIdzB.
query.setParameter("name", name); D7OPFN7`
return query.list(); !F~*Q2PZ9
} Afo qCF
z*OQ4_
/* (non-Javadoc) wd0 *"c@
* @see com.adt.dao.UserDAO#getUserCount() A#8Dv&$Pr
*/ O`Ge|4
publicint getUserCount()throws HibernateException { KImazS^
int count = 0; zua=E2
String querySentence = "SELECT count(*) FROM jY ~7-
sboX<
user in class com.adt.po.User"; U8icP+Y
Query query = getSession().createQuery o~={M7m
$C~OV@I
(querySentence); x/xd
count = ((Integer)query.iterate().next ;_?RPWZ;MO
o+
0"@B
()).intValue(); H?W8_XiN
return count; hF7#i_UN<
} 2JS&zF
_S;Fs|p_
/* (non-Javadoc) <R@w0b>
* @see com.adt.dao.UserDAO#getUserByPage
v{*#
@G:aW\Z
(org.flyware.util.page.Page) l[Rl:k!
*/ 0ntf%#2{
publicList getUserByPage(Page page)throws j SX VLyz
y%=t((.Z
HibernateException { Cz]NSG 5
String querySentence = "FROM user in class )%=oJ!)
>r~!'Pd!
com.adt.po.User"; gQ~X;'
Query query = getSession().createQuery :;u?TFCRx
mQy!*0y
(querySentence); Y> f 6
query.setFirstResult(page.getBeginIndex()) C6cEt5
.setMaxResults(page.getEveryPage()); L>1i~c&V
return query.list(); B|(M xR6m
} cR"?EQ] `N
Kitx%P`i
} #JIh-h@
Fi_JF;
2fv`O
IW-lC{hK
(_'Efpg|
至此,一个完整的分页程序完成。前台的只需要调用 si.w1
#gd`X|<Ch
userManager.listUser(page)即可得到一个Page对象和结果集对象 KG8Km
>)p8^jX
的综合体,而传入的参数page对象则可以由前台传入,如果用 ^YwTO/Q|
pQf5s7
webwork,甚至可以直接在配置文件中指定。 *='J>z.]
j65qIw_Z
下面给出一个webwork调用示例: j`pX2S
java代码: :q,tmk h
R@Kzdeo
UjrML
/*Created on 2005-6-17*/ k x26nDT(
package com.adt.action.user; MeXGE
380M&Guh
import java.util.List; cas5
I#U"DwM
import org.apache.commons.logging.Log; \>@QJ
import org.apache.commons.logging.LogFactory; c1L0#L/F6"
import org.flyware.util.page.Page; jX8,y
`bx}!;{lx
import com.adt.bo.Result; z),@YJU"z
import com.adt.service.UserService; 8C(@a[V
import com.opensymphony.xwork.Action; !H[K"7w
"hi)p9 _cR
/** HE0@`(mCpa
* @author Joa uF89B-t
*/ 236,o
{9e
publicclass ListUser implementsAction{ b6y/o48
u~y0H
privatestaticfinal Log logger = LogFactory.getLog fce~a\y0
r[}5<S Q
(ListUser.class); ,8^QV3
ym~
private UserService userService;
f7_EqS=(
<+\
w .!
private Page page; M!j: 2dT"
_cw~N
p
privateList users; /3mt=1/~{B
oYn|>`+6:y
/* Kk?C
* (non-Javadoc) ;('(Yn7~
* [9U::
* @see com.opensymphony.xwork.Action#execute() 0V_dg |.
*/ 6mAaFDI,R
publicString execute()throwsException{ +P5\N,,7R
Result result = userService.listUser(page); %SHgXd#X
page = result.getPage(); yRF
%SWO
users = result.getContent(); {InD/l'v6n
return SUCCESS; ?@uyqi~:U
} C0> Z<z
zm7IkYF
/** zF-R$_]av
* @return Returns the page. Y)oF;ko:
*/ NplWF\5y
public Page getPage(){ .lt|$["
return page; -mur`tC
} B
!}/4"
\p%,g&^ x
/** j{?ogFfi
* @return Returns the users. [W#M(`}D
*/ :3aZ_
publicList getUsers(){ R$Or&:E ^
return users; S_ELV#X
} \J0fr'(S
E[8R
)xC@
/** <<5x"W(,
* @param page k=D}i\F8
* The page to set. cU
*/ c ?H@HoF
publicvoid setPage(Page page){
e#/SFI0m
this.page = page; 5_\+8A*
} V9%!B3Sb
jM%8h$&E
/** %Xfy.v
* @param users {I:nza
* The users to set. zlhHSy K
*/ Q`{2yU:r
publicvoid setUsers(List users){ c ?(X(FQ
this.users = users; bnYd19>
} LZ 3PQL
a58]#L~
/** $YztLcn
* @param userService r-aCa/4y!
* The userService to set. $(=0J*ND"
*/ xb22:
publicvoid setUserService(UserService userService){ 8EBy5X}US
this.userService = userService; OoqA`%
} u>y/<9]q8
} 1> IA9]D7
z3mo2e
S+*g
Ht_7:5v&
|JVp(Kx
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, #P)(/>nF
u P&<
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 ZtofDp5B
D%%@+3a
么只需要: D]StDOmM
java代码: "t!_bma
"eb+O
XKQ\Ts2<k
<?xml version="1.0"?> P'<D0
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 31)eDs
_>=QZ`!r
1.0//EN" "http://www.opensymphony.com/xwork/xwork- 'U/X<LCl
'irHpN6n
1.0.dtd"> I/`\>Hk
@5:#J!
<xwork> }*>xSb1
k,0lA#>
<package name="user" extends="webwork- l/6$BPU`
t[=teB v<
interceptors"> ,E3Ze*(U
^EFVjGM
<!-- The default interceptor stack name fB"It~ p
<]wQ;14;H
--> FesUE_L2$
<default-interceptor-ref <[Y@<
4E
32DG*
name="myDefaultWebStack"/> <C{uodFll
dR@XwEpP
<action name="listUser" bb}$7v`G
<<~swN
class="com.adt.action.user.ListUser"> >'g>CD!
<param <R.Ipyt.
FwaYp\z
name="page.everyPage">10</param> %RD%AliO}K
<result t1rAS.z&
+
X0db
name="success">/user/user_list.jsp</result> -hpC8YS
</action> )gPkL
r
!'f.g|a
</package> ,%4~ulKMn
m$!Ex}2
</xwork> r[W
Ir|r7
6~.{~+Bd
/pYp,ak
%z"${ zw
S<Od`I
(>M?
iB
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 Gq0Q}[53
I|/\ L|vo
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 j&w4yY
6H'W]T&
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 'd |*n#Dqc
SEXmVFsQ
[iGL~RiXtn
!v68`l15
(y!V0iy]
我写的一个用于分页的类,用了泛型了,hoho L7OFZ|gUz
9D,/SZ-v
java代码: rJw
Ws
U])$#/ v
vHM,_I{
package com.intokr.util; r"bV{v
4ztU) 1
import java.util.List; \Jm^XXgS
t~kh?u].j
/** 716r/@y$6
* 用于分页的类<br> eYD -8*
* 可以用于传递查询的结果也可以用于传送查询的参数<br> M=#'+CF}W
* vV*i)`IXe
* @version 0.01 GB8>R
* @author cheng Y@2v/O,\
*/ ;Yu|LaI\<m
public class Paginator<E> { ,ocAB;K
privateint count = 0; // 总记录数 "fOxS\er
privateint p = 1; // 页编号 1^AG/w
privateint num = 20; // 每页的记录数 DM=`hyf(v
privateList<E> results = null; // 结果 (Q[(] dfc
A?4s+A@Eg
/** 1;"DIsz@d
* 结果总数 &b9bb{y_$K
*/ x't@Mc
publicint getCount(){ f`bRg8v
return count; 4H_QQ6
} |}D5q| d@n
v]c+|nRs
publicvoid setCount(int count){ I08W I u
this.count = count; u`Abko<D
} ':#DROe!
:)DvZx HE@
/** ^
RIWW0
* 本结果所在的页码,从1开始 S:{`eDk\A_
* kj/v$m
* @return Returns the pageNo. >bbvQb+j
*/ iCNJ%AZH
publicint getP(){ I~)A!vp
return p; n#"N"6s
} PsO>&Te