Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 @Iv;y*y
}~XWtWbd-
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 l]R0r{{
yLX $SR
据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 ATNOb
1PkCWRpR
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 @^W`Yg)C
18>cfDh;N
。 %t9C
DmiBM6t3N
分页支持类: jhNFaBrS
0CrsZt X
java代码: %fqR
wSTulo: 9
hArY$T&MB
package com.javaeye.common.util; TC\+>LXiZ
9t"Rw ns
import java.util.List; |W">&Rb<t#
):D"LC
publicclass PaginationSupport { i--t
?@#
x *eU~e_jP
publicfinalstaticint PAGESIZE = 30; ,fVD`RR(W?
p
T(M>LP83
privateint pageSize = PAGESIZE; Ux[<g%F"
V2YK T,5
privateList items; M?$[WS
>Jz9wo`
privateint totalCount; y>^^.
IHl q27O
privateint[] indexes = newint[0]; ^OR0Vp>L
N@q}eGe
privateint startIndex = 0; _kj]vbG^;
"s*-dZO
public PaginationSupport(List items, int J!6FlcsZm
RLB3 -=9t
totalCount){ *T|B'80
setPageSize(PAGESIZE); gE-y`2SU
setTotalCount(totalCount); l4Xz r:]
setItems(items); rl*O-S/
setStartIndex(0); Ifj&S'():
} CLb6XnkcA\
VM"cpC_8
public PaginationSupport(List items, int *Z5^WHwg
[VCC+_
totalCount, int startIndex){ tZrc4$D-
setPageSize(PAGESIZE); kNEEu!G
setTotalCount(totalCount); Lsmcj{1d
setItems(items); ^.SYAwL
setStartIndex(startIndex); hvd}l8
} woYD &Oml
ie}OZM
public PaginationSupport(List items, int 5,RUPaE
R?2sbK4Cz
totalCount, int pageSize, int startIndex){ GF'wDi}
setPageSize(pageSize); 'Ts:.
setTotalCount(totalCount); yVd^A2
setItems(items); -EjXVn! vQ
setStartIndex(startIndex); `2~>$Tr
} .J"N}
3dShznlf_*
publicList getItems(){ fV(3RG
return items; Lpchla$
} 5jdZC(q5a
qtGJJ#^,
publicvoid setItems(List items){ .1x04Np!
this.items = items; ^rkKE
dd
} PxHFH pL
!Brtao"m
publicint getPageSize(){ yC,/R371k
return pageSize; WeI+|V$
} |D3u"Y!:^
(JhX:1
publicvoid setPageSize(int pageSize){ N0U/u'J!g
this.pageSize = pageSize; #Ondhy%h[
} )Nv1_en<!
VSj!Gm0LB
publicint getTotalCount(){ ~xH&"1
return totalCount; +Q*`kg'
} !,WGd|oJ
TBhM^\z
publicvoid setTotalCount(int totalCount){ "q4tvcK.
if(totalCount > 0){ B{-7
this.totalCount = totalCount; D7ex{SVA)
int count = totalCount / $6QIYF""
8#I>`z^F
pageSize; G4&s_M$
if(totalCount % pageSize > 0) DA=U=F
count++; W+nu=iQ!
indexes = newint[count]; J3Mb]X)_}
for(int i = 0; i < count; i++){ e5=d
Ev
indexes = pageSize * 9N]Xa
7*'/E#M
i; MfTLa)Rz
} #c!:&9oU
}else{ Nz{dnV{&x;
this.totalCount = 0; rCyb3,W
} OI R5QH
} ]n ?x tI
w-jElV
publicint[] getIndexes(){ 0MQ= Rt
return indexes; #F*|@
} o3ZN0j69|
l/$GF|`U
publicvoid setIndexes(int[] indexes){ Vs>Pv$kW
this.indexes = indexes; w7nt $L5
} #XV=,81w
8WP>u8&
publicint getStartIndex(){ e_BG%+;G,
return startIndex; vL/ 3(Bo7
} X/]@EF
l }{{7~C`
publicvoid setStartIndex(int startIndex){ O9gq <d
if(totalCount <= 0) ;rh.6D l
this.startIndex = 0; A 'qe2]
elseif(startIndex >= totalCount) VFT@Ic#]
this.startIndex = indexes ?-??>& z
.@dC]$2=
[indexes.length - 1]; 61\u{@o$
elseif(startIndex < 0) f*ZU a
this.startIndex = 0; Z1Qz
LvWs
else{ 1CtUf7 `/Q
this.startIndex = indexes ^({)t
wAMg"ImJ
[startIndex / pageSize]; (su,=Z
} " T(hcI
} >nSsbhAe
~ KK9aV{
publicint getNextIndex(){ -luQbGcT3
int nextIndex = getStartIndex() + ia6 jiW x
, ,3lH-C
pageSize; PN}+LOD<t
if(nextIndex >= totalCount) #mH@ /6,#[
return getStartIndex(); :,BAw ,
else 5Iu5N0cn
return nextIndex; bT,:eA
} |@ mz@
Z\$HgG
publicint getPreviousIndex(){ !U`&a=k
int previousIndex = getStartIndex() - 0SpB2>_
h!"2Ux3!x
pageSize; 8K8u|]i
if(previousIndex < 0) W?7l-k=S
return0; ~C-Sr@ a?/
else IQQv+af5
return previousIndex; [|\6AIoS
} GR,2^]<{
$+gQnI3w
} Ht`fC|E
01bCP
$Dg-;I
l![M,8
抽象业务类 ~NGM6+9
java代码: rOIb9:
i4C{3J^
J,a&"eOZ
/** j KU2
* Created on 2005-7-12 "tCI_
Zi;
*/ 6iFlz9XiI
package com.javaeye.common.business; }"Y<<e<z:
I#l}5e5
import java.io.Serializable; verI~M$v{
import java.util.List; &lc@]y8
HC0juT OiO
import org.hibernate.Criteria; 0JR/V68$
import org.hibernate.HibernateException; $C16}^
import org.hibernate.Session; [V}vd@*k
import org.hibernate.criterion.DetachedCriteria; :4AQhn^;"
import org.hibernate.criterion.Projections; Fwm$0=BXL
import QE]@xLz
l;F"m+B!$
org.springframework.orm.hibernate3.HibernateCallback; ZvY"yl?e
import ,%i
Scr,z
T2{e1 =Z7
org.springframework.orm.hibernate3.support.HibernateDaoS V:0IBbh)w
}_Bo:*9B-o
upport; ?pL|eS7
tX*@r
import com.javaeye.common.util.PaginationSupport; B=Hd:P|
]&'!0'3`
public abstract class AbstractManager extends o.s'0xP]
EPo)7<|>
HibernateDaoSupport { ZbRRDXk!
)1 <0c@g=
privateboolean cacheQueries = false; PW*Vfjf4
x;ik
privateString queryCacheRegion; K'OG-fn;
'CBwE&AL
publicvoid setCacheQueries(boolean wGHft`Z
Q\oa<R
D5
cacheQueries){ N$=YL
@m8
this.cacheQueries = cacheQueries; ,@Csa#
} ;W0J
0 '&C5v'
publicvoid setQueryCacheRegion(String g%2G=gR$?z
]dycesc'
queryCacheRegion){ N2h5@*1Y
this.queryCacheRegion = "|\hTRQ
+U
fw
queryCacheRegion; UMcM&yu-
} 3 s\UU2yr
]0i[=
publicvoid save(finalObject entity){ L03I:IJ
getHibernateTemplate().save(entity);
K^{j$
} Aez2n(yac
vuQA-w7
publicvoid persist(finalObject entity){ hB?#b`i^
getHibernateTemplate().save(entity); ;NP-tA)
} ,\`ruWWLb=
<3Ftq=
publicvoid update(finalObject entity){ nC:T0OJv
getHibernateTemplate().update(entity); ^Ks1[xc* `
} @`.4"*@M
0+&WIs
publicvoid delete(finalObject entity){ ;QZG<
getHibernateTemplate().delete(entity); k?cX fj&
} o!xCM:+J
oKGH|iVEe
publicObject load(finalClass entity, /fQcrd7h
e]<Syrk
finalSerializable id){ .+7n@Sc
return getHibernateTemplate().load d%EdvM|)
4DIU7#GG
(entity, id); 'm0WPS/6E
} t/i*.>7
R6~6b&-8
publicObject get(finalClass entity, tbQY&TO1
5{ap
finalSerializable id){ 1I;q@g0
return getHibernateTemplate().get XRaGV~
F'~r?D
(entity, id); '{`KYKLP+
} j)ic7b
d /jx8(0
publicList findAll(finalClass entity){ dcKpsX
return getHibernateTemplate().find("from
u7!gF&tA
U=v>gNba
" + entity.getName()); >A )Sl'
} .)*&NY!nsl
$`xpn#lz
publicList findByNamedQuery(finalString c{'Z.mut
1dD%a91
namedQuery){ MpKXC
return getHibernateTemplate cg )(L;
#m#IBRD :
().findByNamedQuery(namedQuery); &UDbH* !4=
} G-CL \G\n
g.\b@0Uy'
publicList findByNamedQuery(finalString query, AB
$N`+&
(~@.9&cBD
finalObject parameter){ S1k*"><
return getHibernateTemplate Q_T,=y
d 6Y9D=O
().findByNamedQuery(query, parameter); ['QhC( {
} $y;w@^
II^Rp],>
publicList findByNamedQuery(finalString query, ~U+<JC Z
h`Jc%6o
finalObject[] parameters){ QXI~Toddj
return getHibernateTemplate n6[shXH
5ncW
s)
().findByNamedQuery(query, parameters); 1uo |a
} b$w66q8
D[W`
q#W
publicList find(finalString query){ JKKp5~_~
return getHibernateTemplate().find \Vv)(/q {
+sJ{9# 6
(query); fe\'N4
} &[`24Db
}[%F
publicList find(finalString query, finalObject oD%n}
QeY+imM
parameter){ 0ytAn+/"x
return getHibernateTemplate().find Sh;`<Ggi~
%X\J%Fj
(query, parameter); QM!UMqdj
} hgZvti
wgDAb#Zuk
public PaginationSupport findPageByCriteria WLWfe-
lf\"6VIsR
(final DetachedCriteria detachedCriteria){ \;%D;3Au
return findPageByCriteria =ZHN]PP
H!NGY]z*
(detachedCriteria, PaginationSupport.PAGESIZE, 0); )fXxkOd
} uA`e
kW+>"3
public PaginationSupport findPageByCriteria =Q"thsR
<S_0=U
(final DetachedCriteria detachedCriteria, finalint [YQtX_;w
VK9E{~0=
startIndex){ bO6z;D#
return findPageByCriteria "-fyX!
~#EXb?#uS
(detachedCriteria, PaginationSupport.PAGESIZE, gISA13
Pf8_6 z_
startIndex); [:,|g;=Y}
} ~+6#4<M.~
C&q}&=3r
public PaginationSupport findPageByCriteria R||$Wi[$
XffHF^l9F
(final DetachedCriteria detachedCriteria, finalint ;[zZI~wh
B8cg[;e81
pageSize, _2k<MiqCD[
finalint startIndex){ GDj_+G;tO\
return(PaginationSupport) wPyc?:|KD?
;J?fK69%
getHibernateTemplate().execute(new HibernateCallback(){ ^=I[uX-3ue
publicObject doInHibernate sS)tSt{C
zv1,DnkqF
(Session session)throws HibernateException { $IKN7
Criteria criteria = +Kmxo4p
uA?a
DjA
detachedCriteria.getExecutableCriteria(session); F0m[ls$
int totalCount = C#&b`
w6 Y+Y;,'f
((Integer) criteria.setProjection(Projections.rowCount _ru<1n[4~
YU87l
()).uniqueResult()).intValue(); .>`7d=KT
criteria.setProjection EZ Q!~
q9(O=7O]-
(null); 5W{|?l{
List items = s5b<KQ.
!/F-EJOH6C
criteria.setFirstResult(startIndex).setMaxResults v@X[0J_8
Mc
(pageSize).list(); ^[HX#JJ~
PaginationSupport ps = |bRi bB
ZZL%5{w_
new PaginationSupport(items, totalCount, pageSize, LGy!{c
Yv*i69"
startIndex); xoSBMf
return ps; 6yaWxpW
} p8y<:8I
}, true); +'e3YF+'
} a(U/70j
/[3!kW
public List findAllByCriteria(final /Wjf"dG}
<
Lrd(b;
DetachedCriteria detachedCriteria){ ^-}3+YA
return(List) getHibernateTemplate lZ+1A0e
.b%mr:nEt7
().execute(new HibernateCallback(){ oRn 5blj
publicObject doInHibernate gn 9CZ
yErvgf
(Session session)throws HibernateException { 'bef3P9`
Criteria criteria = KbRKPA`
v^IMN3^W
detachedCriteria.getExecutableCriteria(session); Yh%
return criteria.list(); @iz6)2z
} 87VXVI
}, true); `tsqnw
} i];@ e]
"%t !+E>nr
public int getCountByCriteria(final P[cGCmM
YAF0I%PYU
DetachedCriteria detachedCriteria){ qr/N ?,
Integer count = (Integer) 3TD!3p8
l5k]voG
getHibernateTemplate().execute(new HibernateCallback(){ !I8(Y
publicObject doInHibernate r,Pu-bhF
Y0OVzp9 b
(Session session)throws HibernateException { {QLqf
Criteria criteria = ]_)=xF19
HPWjNwM
detachedCriteria.getExecutableCriteria(session); PJcz] <
return
XN'X&J
[TpW$E0H
criteria.setProjection(Projections.rowCount > cJX'U9
=>h~<88#5
()).uniqueResult(); |Oaj
Jux
} !FnH;
}, true); M8lR#2n|
return count.intValue(); dv\oVD
} 4VL]v9
} lO|H:7
Q ?W6
&-Zg0T&tZ
DU4Prjb'
T1b9Zqc)f
=mk7'A>l
用户在web层构造查询条件detachedCriteria,和可选的 3?(||h{
`S7${0e
startIndex,调用业务bean的相应findByCriteria方法,返回一个 ?+#E&F
kjW`k?'s
PaginationSupport的实例ps。 IF*kLl?
hE/y"SP3
ps.getItems()得到已分页好的结果集 I-q@@!=
ps.getIndexes()得到分页索引的数组 #P6;-d@a
ps.getTotalCount()得到总结果数 {=d\t<p*n
ps.getStartIndex()当前分页索引 mE]W#?
ps.getNextIndex()下一页索引 \oGZM0j
ps.getPreviousIndex()上一页索引 D9&FCCiUE
aI8K*D )@
m;LeaD}0
HPj7i;?O
f&>Q6 {*]
B6Tn8@O
(iiyptJ
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 tL4xHa6v]
^Sr`)vP
,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 0)qLW&
w
vi>V6IC4v
一下代码重构了。 >!YI7)
#6JCm!s
我把原本我的做法也提供出来供大家讨论吧: N1!|nS3w
A]vQ1*pnk
首先,为了实现分页查询,我封装了一个Page类: V9m1n=r
java代码: Z,,Wo
%)o
x2TCw
Rf\>bI<.
/*Created on 2005-4-14*/ 18!0Hl>
package org.flyware.util.page; lBTgI"n=eK
D`.CXFI+U
/** Efw/bTEg
* @author Joa |xaA3UA
* ZD0Q<8%
*/ fD|ox
publicclass Page { zUxF"g-W
r jL%M';
/** imply if the page has previous page */ U07n7`2w
privateboolean hasPrePage; d=wzN3 ;-
^fb4g+Au
/** imply if the page has next page */ Fk
1M5Dm
privateboolean hasNextPage; 1}!f.cWV(
=RUKN38
/** the number of every page */ 0:nQGX!N
privateint everyPage; t9x.O
*Qg/W?"m
/** the total page number */ ]}G(@9
privateint totalPage; }EOn=*
+;z4.C{gM
/** the number of current page */ 4aZsz,=
privateint currentPage; e}}xZ%$4|
-]PW\}w1
/** the begin index of the records by the current +3t(kQ
Md_\9G .e
query */ G(4:yK0
privateint beginIndex; G#CWl),=
t L;;Yt
7IZ(3B<87t
/** The default constructor */ q^dI!93n|
public Page(){ nS'0i&<{1
w];t ]q|
} iygdX2
8'#%7+ "=!
/** construct the page by everyPage R{6.O+j`
* @param everyPage Mi'eViH
* */ .'7o,)pJ<
public Page(int everyPage){ dmrM %a}W-
this.everyPage = everyPage; #ZGWU_l}
} TiF$',WMv
:d!.E$S
/** The whole constructor */ J/wot,j^
public Page(boolean hasPrePage, boolean hasNextPage, JVTG3:zD
2@ACmh
F+L q
int everyPage, int totalPage, g >-iBxml
int currentPage, int beginIndex){ |vWx[=`o
this.hasPrePage = hasPrePage; *+qXXCA
this.hasNextPage = hasNextPage; G*wn[o(^j
this.everyPage = everyPage; kG,6;aVZ8
this.totalPage = totalPage; u 8N+ht@
this.currentPage = currentPage; o&LNtl;
this.beginIndex = beginIndex; xb_35'$M
} K$'
J:{yY
tp*AA@~
/** $+[HJ{
* @return )n|:9hc
* Returns the beginIndex. HcQ{ok9u
*/ ~"}-cl,
publicint getBeginIndex(){
{v]A`u)
return beginIndex; c+|,2e
0T
} %qfEFhRC
>48zRi\N
/** 8<?60sj
* @param beginIndex "PJ@Q9n__
* The beginIndex to set. @ZK|k
*/ XRj<2U5
publicvoid setBeginIndex(int beginIndex){ lgA9p
4-
this.beginIndex = beginIndex; "vjz $.
} }e9:2
)+mbR_@,O6
/** 5oWR}qqFK
* @return cD2}EqZ 9
* Returns the currentPage. o $p*C
*/ 0xC{Lf&
publicint getCurrentPage(){ b^5rV5d
return currentPage; MWsBZJRr
} 7ktf =Y
/_woCLwQ#
/** W)w@ju$Ko
* @param currentPage c<-_Vh.:5
* The currentPage to set. 1c+[S]7rY
*/ -Vt*(L
publicvoid setCurrentPage(int currentPage){ L&'2
this.currentPage = currentPage; Y R#_<o
} S1;#58
QSEf
/** + lU:I
* @return :)?w2'O
* Returns the everyPage. n>Q/XQXB
*/ -~v;'zOO
publicint getEveryPage(){ 6#.z:_
return everyPage; e/F=5_Io
} Q6kkMLh
nP4jOq*H
/** pz@_%IUS
* @param everyPage g5X+iV
* The everyPage to set. O\B_=KWDO
*/ ;wgm
'jr
publicvoid setEveryPage(int everyPage){ "DfvoQ P
this.everyPage = everyPage; `gD'q5.z;3
} _~=X/I R
,S}[48$
/** x(5>f9b b
* @return UFm E`|le
* Returns the hasNextPage. ~%k<N/B
*/ VGA?B@
publicboolean getHasNextPage(){ q9yY%
return hasNextPage; ^cDHyB=v4d
} .0cm
mpUNq
wp-*S}TT
/** -GDX#A-J
* @param hasNextPage X]tjT
* The hasNextPage to set. _)zSjFX9
*/ HpuHJ#l
publicvoid setHasNextPage(boolean hasNextPage){ *>9#a0cp
this.hasNextPage = hasNextPage; %{5mkO&,2
} FSIV\ u
d1 D{wZ3g
/** RAR"9 N
.
* @return $2
~RZpS
* Returns the hasPrePage. `8KWZi4
]
*/ )#9/vIQ
publicboolean getHasPrePage(){ \zR{D}aS
return hasPrePage; Elh: %dr Q
} IdUMoLL?
o-_0
/** >QU1_'1r
* @param hasPrePage "<t/*$42
* The hasPrePage to set. yx4B!U
*/
$F`jM/B6
publicvoid setHasPrePage(boolean hasPrePage){ =sPY+~<o
this.hasPrePage = hasPrePage; k2"Z:\?z
} C5\bnk{
<hkg~4EKc
/** ~:D}L
* @return Returns the totalPage. }aRV)F
* Ma:xxsH.
*/ S`5^H~
publicint getTotalPage(){ IO/2iSbW
return totalPage; ABSAle
} 88$G14aXEk
1K"``EvNB
/** KFkKr>S:
* @param totalPage ,Si\ky7L
* The totalPage to set. N9r02c
*/ kZBIXW,G
publicvoid setTotalPage(int totalPage){ =oV8!d%]
this.totalPage = totalPage; iL)q':xz
} z0t6}E<VIR
~2beVQ(U
} bBW(#
Q_a
'{@hBB+ D
6I.N:)=
u7UqN
pj6Q0h)
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 Ge8&_7
/Tv=BXL-
个PageUtil,负责对Page对象进行构造: uB>NwCL;
java代码: P)XkqOGpT9
C=t:0.:PJ
-P]J:7*0?\
/*Created on 2005-4-14*/ M3Q#=yy$D$
package org.flyware.util.page; !t3)j>h:
403%~
import org.apache.commons.logging.Log; P>z k
import org.apache.commons.logging.LogFactory; yYkk0 3
OziG|o@I
/** d7g/s'ZHt6
* @author Joa lNs 'jaD
* l[.*X
*/ >&f .^p
publicclass PageUtil { gEcVQPD@
(9CB&LZ(+E
privatestaticfinal Log logger = LogFactory.getLog CeNpJ
U
SXz
(PageUtil.class); hY7Q$B<
LS{g=3P0
/** ~Us1F=i_Q
* Use the origin page to create a new page v(3nBZHv_!
* @param page yK+76\} I
* @param totalRecords GrGgR7eC#P
* @return "Q`{+|'=E
*/ wO@b=1j
publicstatic Page createPage(Page page, int zO<EbqNe!
?D/r1%Z
totalRecords){ D9B?9Qt2[
return createPage(page.getEveryPage(), L}ud+Wfox
p#HPWW"
page.getCurrentPage(), totalRecords); c=<d99Cu!
} C"PN3>x}j
hun
LV8z
/** a5{CkM&,(
* the basic page utils not including exception #m1e_[
[Qa0uM#SU
handler s[)2z3
* @param everyPage (pm]U7
* @param currentPage e,>L&9] ZI
* @param totalRecords #\"8sY,j
* @return page Y.sf^}
*/ Unc;@=c
publicstatic Page createPage(int everyPage, int L`cc2.F
7=N=J<]pl
currentPage, int totalRecords){ ^QTl (L
everyPage = getEveryPage(everyPage); ICo_O]
Ke
currentPage = getCurrentPage(currentPage); +j_Vs+0
int beginIndex = getBeginIndex(everyPage, E B)j&y_
k2sb#]-/}
currentPage); H6 ( ~6Bp5
int totalPage = getTotalPage(everyPage, B<
P H7
d~tG#<^`
totalRecords); k[R/RhHQ,
boolean hasNextPage = hasNextPage(currentPage, HdGAE1eU]}
,GS8Gu
totalPage); BhJqMK>'S
boolean hasPrePage = hasPrePage(currentPage); pOS:/~I3
;XSRG*3j~4
returnnew Page(hasPrePage, hasNextPage, t(VG#}
everyPage, totalPage, #dE#w#=r
currentPage, J\b,rOI f
TKvUBy
beginIndex); yc8FEn!)&
} 1 h|cr_
E)o/C(g
privatestaticint getEveryPage(int everyPage){ HuBG?4Qd
return everyPage == 0 ? 10 : everyPage; 64z9Yr@
} 6*cm
/xJ,nwp7
privatestaticint getCurrentPage(int currentPage){ d*khda;Vj
return currentPage == 0 ? 1 : currentPage; z[b,:G
} %+|k>?&z7
fu}NH\{
privatestaticint getBeginIndex(int everyPage, int @riCR<fF
.*:SZ3v
currentPage){ f/H rO6~k%
return(currentPage - 1) * everyPage; ?`_US7.@
} + _rjA_
aj51%wKMb:
privatestaticint getTotalPage(int everyPage, int .%+'Ts#ie
ePa:_?(
totalRecords){ CTp~bGIv!=
int totalPage = 0; N{46DS
ag]b]K
if(totalRecords % everyPage == 0) l<<0:~+q
totalPage = totalRecords / everyPage; QbP
W_)N
else w-FZ`OA`D
totalPage = totalRecords / everyPage + 1 ; 9*GwW&M%1_
B]ul~FX
return totalPage; H"WkZX
} J:dF^3Y
*>V6KW
privatestaticboolean hasPrePage(int currentPage){ D{Y~kV|
return currentPage == 1 ? false : true; w5gN8ZF3
} 6%H8Qv
,w; ~R4x
privatestaticboolean hasNextPage(int currentPage, VQU [5C
eJ+;!0
int totalPage){ L~x3}o$-o
return currentPage == totalPage || totalPage == h>sz@\{
OYzt>hdH
0 ? false : true; #B8`qFpQC
} }oigZI(1
!;{@O`j?b
GRCc<TM,U
} }X$vriW
Y;6<AIx>
#QXv[%k
Wg[?i C*~
g9}u6q
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。 Y'i0=w6G
V2g,JFp&
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 .3?'+KZ,
+ L;[-]E8
做法如下: D%(9ot{!e
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 ^c83_93)R
bxyEn'vNvQ
的信息,和一个结果集List: tPP nW
java代码: Wv_5sPqLW
7J~6J.m
hE\,4c1
/*Created on 2005-6-13*/ oo)P(_"u
package com.adt.bo; -}%'I]R=
R"6Gm67 t
import java.util.List; Kv:U QdnU[
#i-!:6sLA
import org.flyware.util.page.Page; m?'5*\(ST
bR?-B>EB
/** Fe.Y4\xz
* @author Joa 7U:,:=
*/
2_vE
publicclass Result { (9';zw
LeO
))
private Page page; Qc;`nck
H. uflO
private List content; hghtF
cE 8vSQ%
/** ?u"(^93f
* The default constructor K6KEdXM4
*/ cCFSPT2fq[
public Result(){ k^Tu9}[W1
super(); O}NR{B0B3&
} qnW5I_]
l<PGUm:_
/** Fly@"W4a
* The constructor using fields '&Q_5\Tn
* g,Kb9['
* @param page ZB:Fjq
* @param content !s.G$ JS<
*/ jPPaL]
public Result(Page page, List content){ |(}uagfrd
this.page = page; *0{MAm
this.content = content; $qD8vu )|j
} q?[{fcNh$
d%1S6eYa'
/** }!0,(<EsV
* @return Returns the content. {-^>)
iJqt
*/ }E]`ly<Z
publicList getContent(){ Il2DZ5-
)
return content; -kES]P?2
} idGkX
?
&_,^OE}K_:
/** rr3NY$W
* @return Returns the page. j_&/^-;e
*/ TcZ
Ci^1F
public Page getPage(){ 1KruGq~
return page; zF;}b3oIo
} 86/CA[Y-
L}nj#z4g
/** <%J dQ82?
* @param content |?s%8c'w=
* The content to set. *{Wh-bc
*/ J4j?rLR3p
public void setContent(List content){ [Qy]henK
this.content = content; 9V zk:zOT
} s.1(- "DU
;s"m*
4N
/** u):z1b3*?
* @param page pTGq4v@6x
* The page to set. qw%4j9}
*/ NxNR;wz>l
publicvoid setPage(Page page){ @MtF^y
this.page = page; uWx/V+w
} PHfGl
} aC]~
?P<&8eY
uP|AP
Vt
n$*ML
;ZjQy,H%
2. 编写业务逻辑接口,并实现它(UserManager, RduA0@g0
(d^pYPr{
UserManagerImpl) ~S|Vd
java代码: CEYHD ?9k8
m %ET!+
&lBfW$PZjk
/*Created on 2005-7-15*/ |xQj2?_z*
package com.adt.service; {aGQ[MH\9
1uB}Oe2~
import net.sf.hibernate.HibernateException; Zdh4CNEeFP
kC|tv{g#>
import org.flyware.util.page.Page; xw%?R=&L
yu#Jw
import com.adt.bo.Result; .Yha(5(
feNr!/
/** 6 Y&OG>_\
* @author Joa ' AeU
*/ n9bX[+#d
publicinterface UserManager { ji A$6dZU
3WPMS/
public Result listUser(Page page)throws VxjHB?)
&9o @x]) @
HibernateException; AKa{C
f
#A:I|Q 1$g
} xd(AUl4qY
k]R O=/ ?M
L4Nk+R;
zG [-n.
'G-VhvMv
java代码: .vG6\U7
BqR;d
l,6="5t
/*Created on 2005-7-15*/ hH"3Y}U@
package com.adt.service.impl; lG\lu'<C
J4`08,
import java.util.List; 5uDQ*nJ|
S`0@fieOf
import net.sf.hibernate.HibernateException; jq.@<<j|$
,e.y4
vnU
import org.flyware.util.page.Page; N:L<ySJ7
import org.flyware.util.page.PageUtil; eDaVoc3
akd~Z
import com.adt.bo.Result; $|(roC(
import com.adt.dao.UserDAO; }{iR+MX
import com.adt.exception.ObjectNotFoundException; 14oD^`-t
import com.adt.service.UserManager; fD,#z&
C,tlp
/**
>kC@7h5)
* @author Joa eWwSD#N#
*/ @q^WD_k
publicclass UserManagerImpl implements UserManager { #\`6ZHW
gkBat(Uc
private UserDAO userDAO; H[-zQ#I9
O,^,G<`
/** >IoOCQQ*
* @param userDAO The userDAO to set. !m_'<=)B4~
*/ O "{o
(
publicvoid setUserDAO(UserDAO userDAO){ Em4TEv
this.userDAO = userDAO; = @3Qsd
} W!IK>IW"
} k5pfz
/* (non-Javadoc) ld9zOq
* @see com.adt.service.UserManager#listUser .YS[Md{
Lg Bs<2
(org.flyware.util.page.Page) /x$ jd)C
*/ <6(u%t0k5
public Result listUser(Page page)throws r\Man'h$
WqYl=%x"{V
HibernateException, ObjectNotFoundException { {_k 6 t
int totalRecords = userDAO.getUserCount(); {tWfLfzU
if(totalRecords == 0) /eIwv31
throw new ObjectNotFoundException l l&iMj]
u;=("S{"0
("userNotExist"); <#`<Ys3b*!
page = PageUtil.createPage(page, totalRecords); ^GRd;v=-@
List users = userDAO.getUserByPage(page); uidE/7
returnnew Result(page, users); 6GJ?rE E/
} z#,?*v
yGS._;#R
} T( ;BEyc?
Oh8;YE-%
:U r%.0
(%I`EAR
Lo;T\CN
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 =faV,o&{`
7Kh+m@q.
询,接下来编写UserDAO的代码: tM@TT@.t~
3. UserDAO 和 UserDAOImpl: k)S7SbQ
java代码: !3HMGzt
v t(kL(}v
U6M4}q(N]
/*Created on 2005-7-15*/ zEks4yd
package com.adt.dao; DbOWnXV"o
_Z8zD[l
import java.util.List; N|7._AR2
;Vp&f%u+v
import org.flyware.util.page.Page; m4 4aKqw)
/]+t$K\cBq
import net.sf.hibernate.HibernateException; .5ingB3%
zH|!O!3"4
/** JY>]u*=
* @author Joa CrqWlO
*/ Dj<Vn%d*
publicinterface UserDAO extends BaseDAO { 7&T1RB'>
u9VJ{F
publicList getUserByName(String name)throws
/D~z}\k
$9hOWti
HibernateException; T[<9Ty'^
"G4{;!0C
publicint getUserCount()throws HibernateException; 1h)I&T"kZ
,Zs-<e"
publicList getUserByPage(Page page)throws oq0G@
ZYL]|/"J9
HibernateException; _-^KqNyy
?]sj!7
} e%UFY-2
W6wgX0H
>L=l{F6
p
Y|1kE;
MNJ$/l)h
java代码: L0uN|?}
BJ{mX>I(
N %0F[sY6
/*Created on 2005-7-15*/ 8G{} r
package com.adt.dao.impl; jUjQ{eT
B-eYWt8s
import java.util.List; 5ue{&z
@T
81aY*\
import org.flyware.util.page.Page; ^Z}INUv]7
V1"+4&R^T_
import net.sf.hibernate.HibernateException; 'f5,%e2#
import net.sf.hibernate.Query; ]2Lwd@
[qid4S~r,&
import com.adt.dao.UserDAO; &LYU#$sj
pT[C[h:
/** /4=O^;
* @author Joa e'7!aysj
*/ #M8"b]oh6
public class UserDAOImpl extends BaseDAOHibernateImpl eR5swy&
2;6p2GNSh
implements UserDAO { C\EV$U,
h^[K= J
/* (non-Javadoc) Zx`hutCv
* @see com.adt.dao.UserDAO#getUserByName 5$zC,g*#
t|%iW%m4
(java.lang.String) =zI
eZ7
*/ nDaQ1
publicList getUserByName(String name)throws "3}Bv
X
bCE[oi6hb
HibernateException { !&19%C4
String querySentence = "FROM user in class ?b2%\p`"
K4l,YR;r
com.adt.po.User WHERE user.name=:name"; t;E-9`N
Query query = getSession().createQuery Af *^u|#
u^V`Ucd"R
(querySentence); vp-)$f&
query.setParameter("name", name); Pk*EnA)
return query.list(); 5z#>>|1>#
} l} h<2
YMJjO0
/* (non-Javadoc) i mJ{wF
* @see com.adt.dao.UserDAO#getUserCount() mDj:w#q
*/ dr:)+R
publicint getUserCount()throws HibernateException { V&NOp
int count = 0; ^$yr-p%-
String querySentence = "SELECT count(*) FROM [l'~>
PsLuyGR.<
user in class com.adt.po.User"; =;c? 6{<1
Query query = getSession().createQuery AA yzT*^
UyIjM;X
(querySentence); JNk
]$ xz
count = ((Integer)query.iterate().next Az"3f
@KNp?2a
()).intValue(); O2A Z|[*I
return count; Ks!.$y:x
} !y?g$e`
%'t~+_
/* (non-Javadoc) :9K5zD
* @see com.adt.dao.UserDAO#getUserByPage 2rD`]neA
f*kT7PJG
(org.flyware.util.page.Page) xOD;pRZQ
*/ j1<@*W&b
publicList getUserByPage(Page page)throws 1kTJMtZG~
^=Up UB
HibernateException { 7uxy<#Ar
String querySentence = "FROM user in class l=bB,7gL
%n!s{5:F
com.adt.po.User"; 8M:;9a8fh
Query query = getSession().createQuery R-hqaEB
Z/56JYt!~
(querySentence); #!9aTp).AL
query.setFirstResult(page.getBeginIndex()) B||^sRMX
.setMaxResults(page.getEveryPage());
:S?'6lOc(
return query.list(); y]M/oH
} E
jBEZL|_
bg[q8IBCd
} R}Z"Yxx
g2 4)GjDi
0.|tKetHq
sDWX} NV
_vvnxG!x&
至此,一个完整的分页程序完成。前台的只需要调用 h^34{pKDn
hRGK W
userManager.listUser(page)即可得到一个Page对象和结果集对象 c9iCH~
#).om*Xh
的综合体,而传入的参数page对象则可以由前台传入,如果用 /3rt]h"
3}n=o d=
webwork,甚至可以直接在配置文件中指定。 WynHcxC
;c<:"ad(
下面给出一个webwork调用示例: JTl
37j
java代码: ,Ea.ts>
0qZ{:}`3
t'0r4&\
/*Created on 2005-6-17*/ U}7$:hO"dX
package com.adt.action.user; \wO)w@"
8R8J./i.K
import java.util.List; 5GT,:0
ZK3?"|vhC
import org.apache.commons.logging.Log; ~"brfjd|
import org.apache.commons.logging.LogFactory; hSr#/d w&
import org.flyware.util.page.Page; p;BdzV>
4$d|}ajH
import com.adt.bo.Result; d/Fjs0pt
import com.adt.service.UserService; `;5UlkVZ5
import com.opensymphony.xwork.Action; az0( 54M
!tHqF
/** 18V*Cu
* @author Joa esbxx##\
*/ +JBhw4et;.
publicclass ListUser implementsAction{ 0O"GI33Mg
BP*gnXj
privatestaticfinal Log logger = LogFactory.getLog 9=
\bS6w*
xWn.vSos
(ListUser.class); D-A#{e _
@+B
.<@V
private UserService userService; C6CX{IA]
@QVAsNW:O
private Page page; IS]0 3_uQ
>Mrz$
z{x
privateList users; m'oVqA&
Joq9.%7Q
/* q.~.1
'`!
* (non-Javadoc) 26.iFt/:
* Z(*nZT,
* @see com.opensymphony.xwork.Action#execute() bHWy9 -
*/ X#1So .}c
publicString execute()throwsException{ }B^s!y&b
Result result = userService.listUser(page); ZEUd?"gaR
page = result.getPage(); DTn=WGm)
users = result.getContent(); %!p14c*J H
return SUCCESS; vy@;zrs
} ^ yH|k@y
NQ@ EZoJ
/** T?^AllUZQR
* @return Returns the page. nLQ
3s3@1>
*/ X&
O
o1y
public Page getPage(){ z=BX-)
return page; i
LK8Wnrq
} l
yO_rZT
B2WPjhzD
/** 0MrtJNF]_O
* @return Returns the users. q,$UKg#i
*/ .'5yFBS
publicList getUsers(){ 2~ Gcoda
return users; &FkKnz4IZ
} n*@^c$&P
/o+,
=7hY
/** J>]' {!+
* @param page +7N6]pK|"
* The page to set. ZCbxL.fFz
*/ m$pXe<
publicvoid setPage(Page page){ NVeb,Pf
this.page = page; %jKR\f G
} @Eqc&v!O
g%1!YvS3v
/** 91mXv Q:u
* @param users #x)G2T'?
* The users to set. V{ra,a*
*/ H<X4R
publicvoid setUsers(List users){ 6:ZqS~-
this.users = users; #}:VZ2Z
} "g>uNtt~
~W%A8`9
/** Wy)|-Q7
* @param userService 1fViW^l_
* The userService to set. |>jlY|
*/ D:8-f3
publicvoid setUserService(UserService userService){ 8[(c'rl|)|
this.userService = userService; UFouIS#L
} pb_mW;JVu
} q|=tt(}G
%zb7M%dC6`
&=X1kQG
QbxjfW"/+
(@uQ>dR:
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, g0cCw2S
UyD=x(li
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 H,:Cg:E/^
b;9v.MZ4>g
么只需要: 7{v0K"E{
java代码: 08yTTt76t
j)'V_@
IC92lPM }
<?xml version="1.0"?> _Dwn@{[(8
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork scJ`oc:<J
)amdRc
1.0//EN" "http://www.opensymphony.com/xwork/xwork- L4
x
/uW6P3M
1.0.dtd"> \eI )(,A
f*2V
<xwork>
|cWW5\/
#wx0xQ~,J
<package name="user" extends="webwork- l
\xIGs
1nBE8
N
interceptors"> fG0rUi(8
@l$cZie
<!-- The default interceptor stack name W_O,Kao
f^:9gRt
--> .fUqsq
<default-interceptor-ref W-7yi`5
&p=|z2 J
name="myDefaultWebStack"/> at6f(+
}1N)3~
<action name="listUser" IDdhBdQ
EOVHTDkKf
class="com.adt.action.user.ListUser"> .6(Bf$E
<param ?n? Ep [D
lOI(+74
name="page.everyPage">10</param> 8
x|NR?
<result <4rF3 aB-
;G;vpl
name="success">/user/user_list.jsp</result> 3L=vsvO4
</action> :pDw gd
<IK8Ucp
</package> DK*2d_
HTf7r-
</xwork> vRn^n
4LUFG
pjIXZ=
6.KR(V
\hv*`ukF
#u|;YC
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 Z;7f
D
W*`2lf
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 Z&JW}''n|F
hh
<=D.u
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 Yt0
l'B%[u
9p>3k&S
*2=:(OK
vRRi"bo
8'Z9Z*^h#x
我写的一个用于分页的类,用了泛型了,hoho x8b w#
/bfsC&
3
java代码: KB*[b
#E{OOcM
ldI;DoE#U1
package com.intokr.util; G?'L1g[lc
}4A+J"M4y
import java.util.List; m`4Sp#m
+)L
'qbCSM
/** S[X bb=n
* 用于分页的类<br> S-.!BQ@RMZ
* 可以用于传递查询的结果也可以用于传送查询的参数<br> FyZw='D
* @"'1"$
* @version 0.01 y?CEV-3+
* @author cheng 19bP0y
*/ ,t*#o&+
public class Paginator<E> { #*}4=
privateint count = 0; // 总记录数 l4L&hY^
privateint p = 1; // 页编号 l')?w]|
privateint num = 20; // 每页的记录数 kX+y2v(2++
privateList<E> results = null; // 结果 wKXKc\r
KosAc'/ M
/** Z3~$"V*ZB{
* 结果总数 -'5:Cq
*/ f{^C+t{r
publicint getCount(){ 42ttmN1F
return count;
Mf/zSQk+
} !OPa
`kSh
]{.rx),
publicvoid setCount(int count){ |v[{k>7f
this.count = count; %89f<F\V
} ;}=v|Dr&I.
A4Q8^^byY
/** **fJAANc
* 本结果所在的页码,从1开始 1ncY"S/VO
* % ]r@vjeyd
* @return Returns the pageNo. xo7H^!_
*/ oizD:|
publicint getP(){ )/Ee#)z*
return p; ?9OiF-:n
} 0Evmq3,9
6b6}HO
/** Q$iv27
* if(p<=0) p=1 )O#>ONm^
* [0Z
r z+q
* @param p a}hpcr({?
*/ J+Q
;'J
publicvoid setP(int p){ 2/E3~X7
if(p <= 0) |9~{&<^X
p = 1; F1w~f
<
this.p = p;
jiC;*]n
} daGGgSbh
C8-4 m68"
/** &r/a\t,8n
* 每页记录数量 a^,6[
*/ m9wV#Ldu
publicint getNum(){ {S'xZ._=
return num; #gUM%$
} ncu
&<j }U
=5[}&W
/** `k
a!`nfo
* if(num<1) num=1 2|qE|3&{'
*/ w2@ `0
publicvoid setNum(int num){ ~{=+dQ
if(num < 1) FxTOc@<
num = 1; 0 #VH=p ga
this.num = num; CsQ}eW8uEf
} n;xtUw6\
$s)G0/~W
/** CLdLO u"
* 获得总页数 2%rAf8=
*/ iNT 1lk
publicint getPageNum(){ IT'~.!o7/
return(count - 1) / num + 1; bJx{mq
} NyeGa
.B6$U>>NS^
/** _^0yE_ili
* 获得本页的开始编号,为 (p-1)*num+1 5owUQg,W
*/ Q/1
6D
publicint getStart(){ M$FQoRwH
return(p - 1) * num + 1; 5A>W;Q\4
} "m3u}!`3
Y"K7$+5#\
/** dSS_^E[{
* @return Returns the results. [6FCbzS_W
*/ u;F++$=
publicList<E> getResults(){ &g\D-At
return results; =L#tSa=M"
} 05TZ
s~Ni\SF
public void setResults(List<E> results){ f)({;,q
this.results = results; uV#/Lgw{M
} 8]YFlW9
7M<7^)9
public String toString(){ di
"rvw;R
StringBuilder buff = new StringBuilder : N> 5{
V+nqQ~pJ&
(); dScit!T"
buff.append("{"); Io|NL6[
buff.append("count:").append(count); B=(m;A#G
buff.append(",p:").append(p); :eo2t>zF-<
buff.append(",nump:").append(num); Om\?<aul
buff.append(",results:").append 0N;Pb(%7UU
"e&S*8QhM
(results); k =ru)
_$2
buff.append("}"); z%}^9
return buff.toString();
Qx>S>f
} /E2/3z
:y"Zc1_E
} {[m %1O1
94 H\,}i8
JY"<b6C^