Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ld(60?z>FH
!Yc:yF
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ^fF#Ej1
JpXv+V
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 9d1km~
P#TPI*qw
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 QGNKQ`~
.vHHw@
。 rQv5uoD
jtoS{B,
分页支持类: [P}Bq6;p
Yo %U{/e
java代码: t'K+)OK
;"D}"nL
M8H hjoo
package com.javaeye.common.util; ]I*RuDv}
k _t|)
J
import java.util.List; aQoB1qd8
7 2$S'O%,0
publicclass PaginationSupport { 1V,@uY)s
fDr$Wcd~
publicfinalstaticint PAGESIZE = 30; 7#JnQ|
]
#JYl%=#,
privateint pageSize = PAGESIZE; ]j0+4w
{^oohW -
privateList items; "e-z2G@z
w,P@@Q E
privateint totalCount; co,0@.i
];5J
privateint[] indexes = newint[0]; 3?E7\\/R
B2r[oT R
privateint startIndex = 0; jNxTy UU
=*fq5v
public PaginationSupport(List items, int #GGa, @O
kO)Y|zQ
totalCount){ 0=,Nz
setPageSize(PAGESIZE); X!h>13fW
setTotalCount(totalCount); |2'WSAWG
setItems(items); .7.1JT#@A7
setStartIndex(0); J>R$K
} &/m^}x/_W
!=S?*E +j)
public PaginationSupport(List items, int o"Xv)#g&
`NhG|g
totalCount, int startIndex){ tHzgZoBz
setPageSize(PAGESIZE); pbKmFweq
setTotalCount(totalCount); v,n 8$,
setItems(items); :G6CWE
setStartIndex(startIndex); 8`S1E0s
} ksq4t
n\;;T1rM
public PaginationSupport(List items, int zgFL/a<
L%H\|>k`
totalCount, int pageSize, int startIndex){ MO0t
setPageSize(pageSize); ((Av3{05H&
setTotalCount(totalCount); ta95]|z"j
setItems(items); _L=-z*a\
setStartIndex(startIndex); `Fcr`[
} "(jD*\8x
bB0/FiY7o
publicList getItems(){ 7a>+ma\
return items; :PV3J0pB~
} wMkHx3XD
V|A)f@ Fs
publicvoid setItems(List items){ a6zWg7 PN
this.items = items; 5ppr;QaB
} ,i6U*
BoT#b^l
publicint getPageSize(){ ~_i=hx
return pageSize; |./:A5_h
} PM!JjMeQh
U
_pPI$ =
publicvoid setPageSize(int pageSize){ OfrzmL<K
this.pageSize = pageSize; =zH)R0!eG
} Tf=1p1!3
ku/vV+&O
publicint getTotalCount(){ mm_)=Ipj>
return totalCount; XRV~yBIS
} ,fiV xn Q
qJ5b;=
publicvoid setTotalCount(int totalCount){ ?o)?N8U
if(totalCount > 0){ uj)vh
this.totalCount = totalCount; BZv:E?1z
int count = totalCount / u~,hTY(%
4,@jSr|I3i
pageSize; xjD$i'V+
if(totalCount % pageSize > 0) p+ReQ.5|
count++; HJb^l 4Q
indexes = newint[count]; !d 4DTo
for(int i = 0; i < count; i++){ ^KD1dy3(
indexes = pageSize * "%Ief4
n?c[ E+i;
i; #"oLz"{
} i<$?rB!i<1
}else{ qsEFf(9G
this.totalCount = 0; k]AL\)
&W
} Zk~Pq%u
} 6W:]'L4!
Hxy=J
publicint[] getIndexes(){ tSni[,4Kq
return indexes; [c;0eFSi2
} 63'%+
cjtcEW
publicvoid setIndexes(int[] indexes){ 1Z?uT[kR
this.indexes = indexes; oNYFbZw
} Vo[.^0
cSv;HN:
publicint getStartIndex(){ B*)mHSs2
return startIndex; H/*slqL
} Hi2JG{i
@/N]_2@8;
publicvoid setStartIndex(int startIndex){ 14l6|a
if(totalCount <= 0)
n gJ{az
this.startIndex = 0; ]):>9q$C
elseif(startIndex >= totalCount) 'Hj([N
this.startIndex = indexes fg,vTpBk
1fV)tvU$
[indexes.length - 1]; N,8.W"fV
elseif(startIndex < 0) E|oOd<z
this.startIndex = 0; {|0YcL
else{ 9*~";{O.Oa
this.startIndex = indexes *yHz#u'
R4 b!?}d
[startIndex / pageSize]; *Cp:<Mnd
} f fI=Bt]t
} d%L/[.&
2zbn8tO
publicint getNextIndex(){ J!|R1
int nextIndex = getStartIndex() + InRRcn(
=/xx:D/
pageSize; mm*nXJ
if(nextIndex >= totalCount) `tuGy}S2
return getStartIndex(); U)iBeYW:
else .i )n1
return nextIndex; E:uTjXt
} yW*,Llb5
!K2QD[x
publicint getPreviousIndex(){ Piw i
int previousIndex = getStartIndex() - dEI!r1~n
M@G\b^ "
pageSize; 7/KK}\NE
if(previousIndex < 0) f`rI]v|@
return0; cM,g,E}
else ;jQ^8S
return previousIndex; Ps(oxj7
} fGA#0/_`
y"8,j m
} x
<aR|r
j%ZBAk)}
-glGOTk
I!(BwYd
抽象业务类 ttB>PTg#
java代码: *2.h*y'u
]R!YRu
<EE^ KR96
/** M(C$SB>
* Created on 2005-7-12 vxi_Y\r=T
*/ !?J-Y
package com.javaeye.common.business; 5-H"{29
h3GUFiZ.
import java.io.Serializable; zmu+un"\j
import java.util.List; u|\?6fz
;;C2t&(
import org.hibernate.Criteria; )lz)h*%#
import org.hibernate.HibernateException;
x|c_(
import org.hibernate.Session; Hj `\Fm*A
import org.hibernate.criterion.DetachedCriteria; m;1/+qs0
import org.hibernate.criterion.Projections; 9s7TLT k
import {:\LFB_
Chad}zU`
org.springframework.orm.hibernate3.HibernateCallback; C7AD1rl
import {61Y;
xzFQ)t&
org.springframework.orm.hibernate3.support.HibernateDaoS [wJ\.9<Oa
/ $s(OFbi#
upport; +!:=Mm
^qVBg BPb
import com.javaeye.common.util.PaginationSupport; /C<p^#g9.
&U`ug"/k
public abstract class AbstractManager extends WWOt>C~zV
r=7!S8'
HibernateDaoSupport { `}L{gssv
)J+A2>
privateboolean cacheQueries = false; ~J#Z7y]p!j
M_%c9g@x
privateString queryCacheRegion; z
yp3+|
iweT@P`
publicvoid setCacheQueries(boolean XWNo)#_3
Akws I@@
cacheQueries){ k!bJ&} Q(b
this.cacheQueries = cacheQueries; 35x]'
} n0EW
U,1
DSq?|H
publicvoid setQueryCacheRegion(String @,2,(=l*C
*5hbD-a:
queryCacheRegion){ J p^#G2
this.queryCacheRegion = }L%2K"8?}
4b,+;
queryCacheRegion; oIj-Y`92!
} E="uDHw+
EDh-pK
publicvoid save(finalObject entity){ 9HPwl
getHibernateTemplate().save(entity); LCzeE7x
} %.'oY%
`ueOb
publicvoid persist(finalObject entity){ je 3Qq1
getHibernateTemplate().save(entity); tJ8:S@E3,
} $b7@S`5
})?-)fFD
publicvoid update(finalObject entity){ @[f$MRp\
getHibernateTemplate().update(entity); 3` D['
} \!w |
zuFPG{^\#
publicvoid delete(finalObject entity){ qzO5p=}
getHibernateTemplate().delete(entity); suFk<^3
} WIAukM8~
k{hNv|:,
publicObject load(finalClass entity, BnDCK@+|Q
""_G4{
finalSerializable id){ .yD
6$!6
return getHibernateTemplate().load l]Ym)QP
5j0 Ib>\
(entity, id); Fq
oh!F
} Gxxz4
OQKc_z'"
publicObject get(finalClass entity, ^|hVFM2
SkCux
finalSerializable id){ m~P30)
return getHibernateTemplate().get =w"Kkj>%oh
/;[x3}[
(entity, id); c^puz2
} &"27U
_V0%JE'
publicList findAll(finalClass entity){ D:z_FNN
return getHibernateTemplate().find("from R?tjobk!
+ 660/ e8N
" + entity.getName()); (ov&iNx
} "!eq~/nk
`CBXz!v!O
publicList findByNamedQuery(finalString o61rTj
fgC@(dvfk
namedQuery){ D/;[x{;E
return getHibernateTemplate QP%Hwt]+
G-R83Orl
().findByNamedQuery(namedQuery); bu $u@:q 6
} Zg>]!^X8
,w9|?%S
publicList findByNamedQuery(finalString query, DO+~
]:']
finalObject parameter){ D@ !r?E`
return getHibernateTemplate _IV!9 JL
q"DHMZB
().findByNamedQuery(query, parameter); 19pFNg'kA
} .5s^a.e'O
3c(mZ
publicList findByNamedQuery(finalString query, Br42Qo2"T>
VN\VTSZh?\
finalObject[] parameters){ rl$"~/ oz
return getHibernateTemplate :O,r3O6
CF\wR;6k
().findByNamedQuery(query, parameters); ;_|4c7
} 6U$e;cr6
U}k@%m,
publicList find(finalString query){ 7sWe32
return getHibernateTemplate().find |-S+ x]9
'O.f}m SS
(query); &
BY\h:
} %4V$')rek
"9"
publicList find(finalString query, finalObject %B1)m A;
"M\rO!f:
parameter){ _O11SiP]
return getHibernateTemplate().find d<HO~+9
jAv3qMQA
(query, parameter); HvKdV`bz
}
4~ L1~Gk
. &`YlK
public PaginationSupport findPageByCriteria >}2
,2
/lPnf7
(final DetachedCriteria detachedCriteria){ =PNkzFUo
return findPageByCriteria l?V#;
A"s?;hv\fS
(detachedCriteria, PaginationSupport.PAGESIZE, 0); gu~R4@3
} B.;@i;7L
3^-R_
public PaginationSupport findPageByCriteria ~gOZ\jm}
HY?#r]Ryt
(final DetachedCriteria detachedCriteria, finalint oOAkwc%)b
a\oz-`ESa
startIndex){ nm]lPK U+Y
return findPageByCriteria 11Qi
_T\
aJF/y3
(detachedCriteria, PaginationSupport.PAGESIZE, ~ qaT
jSP
*tk=D sRW
startIndex); .O(9\3q\
} 1LhZmv
h(J$-SUs
public PaginationSupport findPageByCriteria C&%NO;Ole
gyV`]uqG
(final DetachedCriteria detachedCriteria, finalint 7N@[Rtv
9V&+xbR&
pageSize, [wiB1{/Ls.
finalint startIndex){ UL#:!J/34
return(PaginationSupport) 2Oyw#1tdn
["Tro;K#
getHibernateTemplate().execute(new HibernateCallback(){ #CAZ}];Qx
publicObject doInHibernate _*8 6
C!9mygI
(Session session)throws HibernateException { dTu*%S1Z
Criteria criteria = JKO*bbj
5[r}'08b
detachedCriteria.getExecutableCriteria(session); }LQV2 hKTG
int totalCount = &)JoB
\*qradgx$
((Integer) criteria.setProjection(Projections.rowCount UJ%.KU%Q}
6#K.n&=*
()).uniqueResult()).intValue(); {<gX~./]c
criteria.setProjection !Fxn1Z,
+]NpcE'
(null); W&D{0 i`y
List items = #R31VQwK5
:%j"l7=>
criteria.setFirstResult(startIndex).setMaxResults )Y'g;
ZNk[Jn
[.
(pageSize).list(); ,/TmTX--d
PaginationSupport ps = NZADHO@0
.f. tPm
new PaginationSupport(items, totalCount, pageSize, nN@
Ch
E_[a|N"D
startIndex); z8%qCq
return ps; zSk`Ou8M
} %[9ty`UE
}, true); MtF0/aT
} lcy+2)+
qwnVtD
public List findAllByCriteria(final J kAd3ls
D+! S\~u
DetachedCriteria detachedCriteria){ |8[!`T*s
return(List) getHibernateTemplate 2J$vX(
BhbfPQ
().execute(new HibernateCallback(){ tlg}"lY
publicObject doInHibernate u2$.EM/iae
.3n\~Sn
(Session session)throws HibernateException { |;t{L^
Criteria criteria = LjW32>B
+|8.ymvm
detachedCriteria.getExecutableCriteria(session); ZG#:3d*)
return criteria.list(); 9n_RkW5g
} h05FR[</
}, true); =ud~
} %hZX XpuO
kq?:<!z
public int getCountByCriteria(final G/fBeK$.
uV@'898%5
DetachedCriteria detachedCriteria){ yD.(j*bMK;
Integer count = (Integer) Rbr:Q]zGN
gi5X,:[
getHibernateTemplate().execute(new HibernateCallback(){ +F-Y^):
publicObject doInHibernate ^-mW k?>
?[>Y@we
(Session session)throws HibernateException { -'d`(G"
Criteria criteria = +%KkzdS'
:V#xrH8R
detachedCriteria.getExecutableCriteria(session); omy3<6
return iyr8*L\
99By.+~pX
criteria.setProjection(Projections.rowCount O0`ofFN
AFvv+
ss
()).uniqueResult(); 5rCJIl.
} f?GoBh<
}, true); $v e$Sq
return count.intValue(); i[FYR;C
} tSoF!@6
} y:$qX*+9e
9,\AAISi
q+<,FdG
$?gKIv>g
'/9MN;_
wxj}k7_(`A
用户在web层构造查询条件detachedCriteria,和可选的 QfPw50N;
g+QIhur
startIndex,调用业务bean的相应findByCriteria方法,返回一个 `_ M+=*}
4oryTckS
PaginationSupport的实例ps。 V6((5o#
9kqR-T|Q
ps.getItems()得到已分页好的结果集 WS.g`%
ps.getIndexes()得到分页索引的数组 P_8!Gp
ps.getTotalCount()得到总结果数 Z02EE-A
ps.getStartIndex()当前分页索引 xw_$1
S
ps.getNextIndex()下一页索引 SK@ p0:
ps.getPreviousIndex()上一页索引 45<gO1
/0|1xHs
H]wP\m)
T3SFG]H
yENAc sv
T;{:a-8
(.YSs
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 EL z5P}L6
Ars*H,9>e
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 f2SJ4"X
v.TgB)
一下代码重构了。 <n~.X<6V'
i`];xNR'
我把原本我的做法也提供出来供大家讨论吧: ~7g$TAe{
8Exky^OT|
首先,为了实现分页查询,我封装了一个Page类: yIngenr$
java代码: bT
T>
6biR5&Y5U&
2$!,$J-<Y
/*Created on 2005-4-14*/ es%py~m)
package org.flyware.util.page; S<'_{u z
Q2woCxB
/** 3c wBPqH
* @author Joa #;@I.
* a$^)~2U{
*/ Pw7uxN`
publicclass Page { 2Kr>93O
}opMf6`w
/** imply if the page has previous page */ 1|H4]!7kE
privateboolean hasPrePage; :(yut
|#yT]0L%pA
/** imply if the page has next page */ CAom4Sp'
privateboolean hasNextPage; {TJBB/B1
`D=`xSEYl
/** the number of every page */ sN?Rx}
privateint everyPage; ?YV#
K
`T7TWv"M
/** the total page number */ `l.bU3C
privateint totalPage; /0fsn_
;E.f%
/** the number of current page */ n$7*L9)(C
privateint currentPage; em )%U
)flm3G2u
/** the begin index of the records by the current \awkt!Wa
-Q?c'e
query */ 0a<h,s0"2
privateint beginIndex; D Y4!RjJ47
Gx}`_[-
r#&JfAo
/** The default constructor */ n|DMj[uT
public Page(){ T9]0/>
xFM^-`7
} k4u/vn`&r
qP##C&+#q
/** construct the page by everyPage J65:MaS
* @param everyPage _JTK$\
* */ zF{~Md1
public Page(int everyPage){ t?Qbi)T=z
this.everyPage = everyPage; :Mh\;e
} ;PU'"MeB "
_FcTY5."S
/** The whole constructor */ UHU ,zgM
public Page(boolean hasPrePage, boolean hasNextPage, aot2F60J,
@V5i
@H~oOf
int everyPage, int totalPage, `"yxmo*0
int currentPage, int beginIndex){ 9^?muP<A
this.hasPrePage = hasPrePage; soQ[Zg4}
this.hasNextPage = hasNextPage; O`GF|
this.everyPage = everyPage; r%ebC
this.totalPage = totalPage; OW@)6
this.currentPage = currentPage; ^EkxZ4*g
this.beginIndex = beginIndex; 5jwv! L<n
} bqA`oRb\
VmQ'
/** mEi(DW)(
* @return Qy[S~D_
* Returns the beginIndex. %xQ'i4`
*/ 2e-bt@0t
publicint getBeginIndex(){ <%m1+%mA.
return beginIndex; p9u'nDi
} R4JfH
ElDeXLr'
/** K\8zhY
* @param beginIndex U:3OE97
* The beginIndex to set. 33D2^Sf6"
*/ =mPe
wx'
publicvoid setBeginIndex(int beginIndex){ )X|)X,~+-
this.beginIndex = beginIndex; wF% RM$
} fc<y(uX
3"v>y]$U
/** ']I!1>v$[
* @return o~\.jQQxa
* Returns the currentPage. lA1
*/ y06**f)
publicint getCurrentPage(){ Tbv w?3
return currentPage; ~tRGw^<9
} 9%NobT
^E8qI8s
/** ]$9y7Bhj.
* @param currentPage ?nbu`K6T
* The currentPage to set. EQd<!)HZ
*/ 1ywdcg
publicvoid setCurrentPage(int currentPage){ $0 vT_
this.currentPage = currentPage; xf,A<j(o
} Cc%{e9e*
@H4]Gp ]
/** G `!A#As
* @return b6Z3(!]
]
* Returns the everyPage. |#<z\u }
*/ ` V [4
publicint getEveryPage(){ C,$o+q*)W9
return everyPage; oA7DhU5n
} 2@
9? ~?r
G/(,,T}eG
/** %D:VcY9OC
* @param everyPage S$$SLy:P
* The everyPage to set. #Ktk[ "6
*/ ^dhx/e%s
publicvoid setEveryPage(int everyPage){ hi/d%lNZ
this.everyPage = everyPage; MMpId
Uhr
} '7oCWHq[
FJCORa@?_
/** GK1nGdT]
* @return 1;S?9N_B
* Returns the hasNextPage. 'v
CMf
*/ & /T}
publicboolean getHasNextPage(){ Y`eF9Im,
return hasNextPage; "!AtS
} u%yYLpaKf
qGMU>J.;c
/** 6k>5+ -&_
* @param hasNextPage ^--R#$X
* The hasNextPage to set. K\fD';
*/ Y%0rji
publicvoid setHasNextPage(boolean hasNextPage){ ")vtS}Ekt
this.hasNextPage = hasNextPage; Kb{&a
} U5~aG!E
0#8, (6
/** ;]m;p,$
* @return \#) YS
* Returns the hasPrePage. =p=/@ FN
*/ :A @f[Y'9
publicboolean getHasPrePage(){ z\ONwMl
return hasPrePage; |nnFjGC`~
} S (xs;tZ
'Rsr*gX#
/** _D?/$D7u#%
* @param hasPrePage X`WS&!C<
* The hasPrePage to set. Jj=N+,km
*/ ~1}fL 1~5
publicvoid setHasPrePage(boolean hasPrePage){ D86F5HT}}
this.hasPrePage = hasPrePage; U\qbr.<
} b1i~F45h
e Ru5/y~
/** HK<S|6B7V
* @return Returns the totalPage. '<<@@.(f
* {^N,$,Ab.
*/ pt3)yj&XE
publicint getTotalPage(){ DeNWh2
return totalPage; [f lK
} $/g`{OI]K
k\T]*A
/** U>.5vK.+
* @param totalPage >]gB@tn[
* The totalPage to set. !^98o:"x
*/ ;}U]^LT=
publicvoid setTotalPage(int totalPage){ YzM/?enK}T
this.totalPage = totalPage; :{Z%dD
} ip}%Y6Wj
h?OSmzRLd
} ':_gYA
X o9vE3
WTl0}wi
SSE,G!@
O{\<Izm`D
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 VBDb K|
MmvOyKNZF
个PageUtil,负责对Page对象进行构造: $^^M&[b-
java代码: B]<N7NYn1
=FIZh}JD
HDzeotD
/*Created on 2005-4-14*/ @jMo/kO/A
package org.flyware.util.page; -X7x~x-
!A%
vR\
import org.apache.commons.logging.Log; CVkJMH_
import org.apache.commons.logging.LogFactory; Z`GEF|eh
SIR2 Kc0
/** .-&
=\}^2l
* @author Joa Et-|[ eL
* L[*cbjt[
*/ 0Qvr
g+
publicclass PageUtil { DO*6gzW
^/%Y]d$
privatestaticfinal Log logger = LogFactory.getLog Op~:z<z
7]5~ml3:
(PageUtil.class); Lk#)VGk:
u #}1
M
/** Oe@w$?
* Use the origin page to create a new page PX&}g-M9
* @param page 1(# H%
* @param totalRecords _:tS-Mx@5
* @return |4j6}g\
*/ 9IG<9uj
publicstatic Page createPage(Page page, int (0LA.aBIf
'sa)_?Hy
totalRecords){ B= E/|J</
return createPage(page.getEveryPage(), 4Y1^ U{A+
VbJE zl
page.getCurrentPage(), totalRecords); ^z,B}Nz
} S["r
@<
[kr-gV
/** r^rk@W;[
* the basic page utils not including exception 5?
Y(FhnIC
1'TS!/ll];
handler tq'hiS(b
* @param everyPage s!D2s2b9e
* @param currentPage fQ!W)>mi
* @param totalRecords
u0oTqD?
* @return page bZfq?
*/ 4,X CbcC
publicstatic Page createPage(int everyPage, int bVN?7D(
WpE"A
currentPage, int totalRecords){ $[MAm)c:]{
everyPage = getEveryPage(everyPage); KOXG=P0
currentPage = getCurrentPage(currentPage); &K[~Ab_
int beginIndex = getBeginIndex(everyPage, Bv3B|D&+
`H*mQERb
currentPage); &X`
lh P
int totalPage = getTotalPage(everyPage, tK *y/S
lcReRcjm
totalRecords); knV*,
boolean hasNextPage = hasNextPage(currentPage, oVbs^sbRH
'3Fb[md54
totalPage); N:+EGmp
boolean hasPrePage = hasPrePage(currentPage); ax;<idC}
Zj ^e8u=T
returnnew Page(hasPrePage, hasNextPage, \j wxW6>
everyPage, totalPage, p*YV*Arv
currentPage, 7MJ\*+T|03
Ujvm|ml
beginIndex); :cXN
Fu\C
} X#h a*u~U
*x p_#
privatestaticint getEveryPage(int everyPage){ 0ZI}eZA j
return everyPage == 0 ? 10 : everyPage; y>u|3:z
} 7!Im|7Ty
ttlMZLX{TJ
privatestaticint getCurrentPage(int currentPage){ W}zq9|p
return currentPage == 0 ? 1 : currentPage; 3?_%|;ga
} 'BgR01w J
;KmrBNF
privatestaticint getBeginIndex(int everyPage, int (0_zp`)
IIBS:&;+-
currentPage){ x*TJYST
return(currentPage - 1) * everyPage; k_?OEkgUh
} | lzcyz
Nqd9)WQ
privatestaticint getTotalPage(int everyPage, int N,VI55J:y>
4JO16
totalRecords){ KE5>O1
int totalPage = 0; xc`O\z_)
T4ugG?B*
if(totalRecords % everyPage == 0) c3PA<q[
totalPage = totalRecords / everyPage; <)sL8G9Y
else *(]ZdB_2
totalPage = totalRecords / everyPage + 1 ; `}$bJCSF.n
Jx`7W1%T
return totalPage; +eLL)uk
} }jWg&<5+z
M5_t#[ [
privatestaticboolean hasPrePage(int currentPage){ i 2uSPV!Tf
return currentPage == 1 ? false : true; P;'ZdZ(SLu
} u:l<NWF^
f;,*P,K
privatestaticboolean hasNextPage(int currentPage, 8+Gwv
SDU
fN<Y3^i"
int totalPage){ {:n1|_r4Z
return currentPage == totalPage || totalPage == /"~UGn]R
Q:y'G9b
0 ? false : true; =9p3^:S
} o^owv(
m&(qr5>b
v|]"uPxH?
} jt* B0'Sa
q3K}2g
mC(YO y
Up_"qD6
T;PLUjp}
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。 -'*<;]P+.
01RW|rN
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 Y!Io @{f
m$pRA0s2`
做法如下: ;7H^;+P
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 +/ M%%:>mY
,\RR@~u'
的信息,和一个结果集List: jPx}-_jM
java代码: {L.uLr_?e
_nX8f
&
-m
;n}ECg
/*Created on 2005-6-13*/ 08%Bx~88_%
package com.adt.bo; itc\wn
%S$$*|_G
import java.util.List; pNmWBp|ER
Xi\c>eALO
import org.flyware.util.page.Page; M&Ln'BC
n:1Ijh
1
/** H ="I=}
* @author Joa in K;n
*/ tAY{+N]f
publicclass Result { WlGT&m&2
*uy<Om
private Page page; O;}K7rSc
[U"/A1p
private List content; JB.U&
jPZpJ:
/** b8vZ^8tBV
* The default constructor 7~k=t!gTY
*/ puMbB9)
public Result(){ iY&I?o!Ch
super(); E8p,l>6(f
} ^kz(/c/ ?
P46Q3EE
/** ?gjx7TQ?
* The constructor using fields v#X#F9C
* '4Qsl~[Eh
* @param page AR$SQ_4
* @param content Z`ww[Tbv~
*/ k{UeY[,jb
public Result(Page page, List content){ b&LAk-}[
this.page = page; l5KO_"hy
this.content = content; 27$,D XD
} L<Z,@q`
Xw7'I
/** :rjfAe=s
* @return Returns the content. apfr>L3
*/ iXvrZofE
publicList getContent(){ HTvUt*U1
return content; _)~VKA]""
} n}(A4^=4KQ
K1]3zLnS
/** 1Ax;|.KQH
* @return Returns the page. dB0
UZirb
*/ 1v,R<1)&
public Page getPage(){ 0\@oqw]6hv
return page; V@O)7ND
} gxAy{
t
"VU/Ucb7
/** 6qT-
* @param content rK:cUW0]X
* The content to set. -%^'x&e
*/ >'.: Acn
public void setContent(List content){ rzLW@k
this.content = content; zEukEA^9`
} {s*2d P)
!=a]Awr\
/** 8?YeaMIBB
* @param page q(~|roKA(
* The page to set. jI H^
*/ jiLJiYMg
publicvoid setPage(Page page){ "dvo@n|
this.page = page; hCd? Kti
} VYO1qj
} lCl5#L9
w&Gc#-B
$&KkZ
|d*a~T0
pIYXYQ=Z
2. 编写业务逻辑接口,并实现它(UserManager, .uxM&|0H
aJA( UN45
UserManagerImpl) VfP\)Rl
java代码: &/"a
E
>TBXT+
zR]!g|;f
/*Created on 2005-7-15*/ aW{5m@p{"
package com.adt.service; < *;GJ{
jvL!pEC!
import net.sf.hibernate.HibernateException; 9n;6zVV%`
5$cjCjY
import org.flyware.util.page.Page; w-LENdw
X?n=UebO^
import com.adt.bo.Result; : T7(sf*!*
VO=Ibu&X
/** uZ\+{j=
* @author Joa Z*UVbyC
*/ Vp|?R65S*
publicinterface UserManager { n\JI7A}
2l^_OrE!
public Result listUser(Page page)throws 7C,giCYU
y)CvlI
HibernateException; HTGLFY(&
!U1
vW}H
} 5r~jo7
`8RKpZv&
U,;796h
C1UU v=|
ugE!EEy[^
java代码: ubOXEkZ8N
2{vAs
ZILJXX4
/*Created on 2005-7-15*/ "* F`,I3
package com.adt.service.impl; ~QxW^DGa7]
B%MdJD>
import java.util.List; _6ck@
c1jRj=\
import net.sf.hibernate.HibernateException; g,]m8%GHE
_N^w5EBC]
import org.flyware.util.page.Page; -C3 [:g
import org.flyware.util.page.PageUtil; 6l;2kztGp
DF4CB#
import com.adt.bo.Result; @p
WN5VL
import com.adt.dao.UserDAO; PM#3N2?|E
import com.adt.exception.ObjectNotFoundException; /WE\0bf
import com.adt.service.UserManager; *vuI'EbM
5rdB>8W
/** Ddpcov
* @author Joa ,p#B5Dif/
*/ ,I x>.^|
publicclass UserManagerImpl implements UserManager { /w(g:e
{tY1$}R
private UserDAO userDAO; kmc"`Ogotw
%<(d%&~
/** |l+5E
* @param userDAO The userDAO to set. 8B?U\cfa^
*/ ~~-VScG&
publicvoid setUserDAO(UserDAO userDAO){ ftR& 5!Wm
this.userDAO = userDAO; =&$z
Nc4h
} c3g`k"3*`
?Y,^Moc:
/* (non-Javadoc) 'xxM0Kn`
* @see com.adt.service.UserManager#listUser 7H< IO`
*URT-+'
(org.flyware.util.page.Page) tzIP4CR~F&
*/ 111A e*U
public Result listUser(Page page)throws p'2IlQ\
4^bt~{}
HibernateException, ObjectNotFoundException { f'@ L|&w
int totalRecords = userDAO.getUserCount(); 2tpu v(H;
if(totalRecords == 0) C)EP;5k'!\
throw new ObjectNotFoundException M>p<1`t-&
It&CM,=t
("userNotExist"); TPk?MeVy%W
page = PageUtil.createPage(page, totalRecords); Wtcib-
List users = userDAO.getUserByPage(page); !W@mW
5J|
returnnew Result(page, users); B\)Te9k'
} TaBya0-
DR}I+<*%aD
} _Tor9Tj
nM2<u[{gF
Q'Osw"
(b<0=U
7)r]h?
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 ~ a`[p\
eDZ8F^0
询,接下来编写UserDAO的代码: \+O.vRc"M
3. UserDAO 和 UserDAOImpl: Dn 0L%?_
java代码: S,AxrQc
\j62"
5 k3m"*
/*Created on 2005-7-15*/ /u4RZ|&as
package com.adt.dao; C`g
"Mk8
3rH}/`d4
import java.util.List; 8$\j| mN
j2_j5Hgo
import org.flyware.util.page.Page; xS/W}-dPv
s!/lQo5/
import net.sf.hibernate.HibernateException; `M6"=)twu
>aO.a[AM
/** :QGo
-,6-
* @author Joa tSJ#
*/ W?.469yy
publicinterface UserDAO extends BaseDAO { 7UMZs7L$
0HoHu*+FX
publicList getUserByName(String name)throws pS ](Emn`.
:) lG}c
HibernateException; |di(hY|
'QT~o-U
publicint getUserCount()throws HibernateException; ?`Yu~a{
.k]`z>uv
publicList getUserByPage(Page page)throws (is' ,4^b
$ItmYj.m
HibernateException; s"`~Xnf
m.m6.
} :&vX0
Ce:
?IHt T3'Rt
uv/\1N;V3
FDLo|aP/v
6-_g1vq
java代码: zY_J7,0g
*O~y6|U?
JfN
'11,$
/*Created on 2005-7-15*/ y%i9 b&gDd
package com.adt.dao.impl; Qq`S=:}~x
rz%~=Ca2j
import java.util.List; 3LLG#l)8
qS/}aDk&
import org.flyware.util.page.Page; j*?8w(!
5:IDl1f5
import net.sf.hibernate.HibernateException; -eF-r=FR
import net.sf.hibernate.Query; {kk%_q
//2O#Fg{/
import com.adt.dao.UserDAO; ?pW1}:z
HfVHjF)
/** ?uSoJM`wa!
* @author Joa K'Ywv@
*/ 2j%=o?me^p
public class UserDAOImpl extends BaseDAOHibernateImpl wBXa;.
M\m:H3[
implements UserDAO { `CS\"|z
FE!jN-#
/* (non-Javadoc) GLtWo+g0
* @see com.adt.dao.UserDAO#getUserByName {q)d
H_RfIX)X
(java.lang.String) iN
Oj@3x
*/ w<`0D)mQ
publicList getUserByName(String name)throws I2$DlEke
{k3ItGQ_
HibernateException { =m2_:&@0x
String querySentence = "FROM user in class W:RjWn @<
2~$S @c
com.adt.po.User WHERE user.name=:name"; :lB`K>)iB}
Query query = getSession().createQuery j J{F0o
LRu,_2"
(querySentence); r89AX{:
query.setParameter("name", name); /&Oo)OB;
return query.list(); 0Gs\x
} F}u'A,Hc
>SDQ@63E?
/* (non-Javadoc) c1k[)O~
* @see com.adt.dao.UserDAO#getUserCount() ;Yee0O!d4
*/ !y b06Z\f
publicint getUserCount()throws HibernateException { B8Fb$
int count = 0; )&1v[]%S
String querySentence = "SELECT count(*) FROM ^H.B6h?
Fa>f'VXx
user in class com.adt.po.User"; l{dsm1#W~
Query query = getSession().createQuery 9?,i+\)qK@
>wh v*@Fr
(querySentence); OK80-/8HI
count = ((Integer)query.iterate().next xA
Ez1
S<i1t[E@W
()).intValue(); w&L~+Z<
return count; O.B9w+G=
} 2/4zg
wH o}wp
/* (non-Javadoc) 1;( h0j
* @see com.adt.dao.UserDAO#getUserByPage >; MJm
Q<V(#)*
(org.flyware.util.page.Page) 61H_o7XXk
*/ Xb%Q%"?~
publicList getUserByPage(Page page)throws vWoppt
/*y5W-'d^
HibernateException { fG'~@'P~
String querySentence = "FROM user in class ^ 0YQlT98
L=#NUNiXr
com.adt.po.User"; zfKO)Itd
Query query = getSession().createQuery }e$
h_(M#gG
(querySentence); Wz'!stcp
query.setFirstResult(page.getBeginIndex()) We{@0K/O
.setMaxResults(page.getEveryPage()); S9l,P-X`
return query.list(); 0vjCSU-X
} <rE>?zvm
j$q5m 24L
} ~wDXjn"U&
I0zx'x)F
qqw P4ceG
@??3d9I
ar<8wq<4G
至此,一个完整的分页程序完成。前台的只需要调用 CK n2ZL
_dm0*T ?
userManager.listUser(page)即可得到一个Page对象和结果集对象 @KL&vm(F$
F^gTID
的综合体,而传入的参数page对象则可以由前台传入,如果用 BjfVNF;hk:
I/njyV)H
webwork,甚至可以直接在配置文件中指定。 $97O7j@
/8e}c`
下面给出一个webwork调用示例: cRf F!EV
java代码: '{2]:
S#M8}+ZD,
,)[9RgsE
/*Created on 2005-6-17*/ b$DiDm
package com.adt.action.user; U/enq,-F^
VP
A+/5TW
import java.util.List; 9\.0v{&v
eI:[o
import org.apache.commons.logging.Log; ? #rXc%F
import org.apache.commons.logging.LogFactory; ,7j8+p|},
import org.flyware.util.page.Page; l}/_(*
`*vO8v
import com.adt.bo.Result; l48$8Mgrr
import com.adt.service.UserService; 'UsR/h5T
import com.opensymphony.xwork.Action; 44*#qLN
@6G)(NGD
/** Hq}g1?b
* @author Joa /.0K#J:
*/ mzK0$y#*o
publicclass ListUser implementsAction{ D-/6RVq0m
!-}Q{<2@W
privatestaticfinal Log logger = LogFactory.getLog I9Ohz!RQ
IVh5SS
(ListUser.class); /GGyM]k3
QWOPCoUet
private UserService userService; <5E'`T
ch8VJ^%Ra1
private Page page; 89:nF#
cIw X sx
privateList users; w317]-n
rQ*w3F?:
/* A.r7 ks
* (non-Javadoc) &b#d4p6&l
* U6/7EOW,
* @see com.opensymphony.xwork.Action#execute() Jt5V{9:('
*/ ltuV2.$
publicString execute()throwsException{ /= ;,lC
Result result = userService.listUser(page); [`GSc6j
page = result.getPage(); PFX,X
users = result.getContent(); oUnb-,8n
return SUCCESS; 9$$ Ijf
} VkJ">0k
4nm.ea|
/** ^rJTlh
9
* @return Returns the page. &