Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 D> Z>4:EM
<tf4j3lwH
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 eno*JK
M =yZ5~3
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 $@x3<}X;
aZ@4Z=LK
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 2@08 V|
`"AjbCL
。 Vnh
+2XiK
3mWo`l
分页支持类: rctn0*MP
_QvyFKAM
java代码: gK(E0p"
gywI@QD%#
0#K@^a
package com.javaeye.common.util; r{\cm
Ds
[.6>%G1C
import java.util.List; kjNA~{
Zt lS*id_
publicclass PaginationSupport { Da-F(^E
kUP[&/Lc
publicfinalstaticint PAGESIZE = 30; m6 hA,li
>-X&/i
privateint pageSize = PAGESIZE; FAM`+QtNw
7S]
h:q%%
privateList items; nyQFS
W U<#_by
g
privateint totalCount; H7Y}qP5X
eVU:.fx
privateint[] indexes = newint[0]; 6sP;O,UX
rA`zuYo
privateint startIndex = 0; LvWU
%?
GZZLX19sq
public PaginationSupport(List items, int |]GEJUWtCd
)[p8
totalCount){ #> CN,eiZ
setPageSize(PAGESIZE); ljiq +tT
setTotalCount(totalCount); OzO_E8Kb\
setItems(items); !ox &`
setStartIndex(0); bx6@FKns}
} .&sguAyG
X[@>1tl
public PaginationSupport(List items, int *uEU9fX
]VwAHT&je
totalCount, int startIndex){ `b\4h/~
setPageSize(PAGESIZE); ^iV@NVP
setTotalCount(totalCount); Ne^#5 T
setItems(items); jb7=1OPD_
setStartIndex(startIndex); Ku&(+e
} e3S6+H),I
//J:p,AF
public PaginationSupport(List items, int ]G1j\ wnF
`4k;`a
totalCount, int pageSize, int startIndex){ s{s0#g
setPageSize(pageSize); V ?_%Y<|L
setTotalCount(totalCount); (S2<6Nm8
setItems(items); hJ}G5pX
setStartIndex(startIndex); \&TTe8
} E32z(:7M
ise@,[!
publicList getItems(){ SbGp
return items; Gi<f/xQk>
} iGha pD
QlXy9-oJ"
publicvoid setItems(List items){ SQ.4IWT(hR
this.items = items; htF&VeIte
} (vI7qD_
Ce0I8B2y
publicint getPageSize(){ wz,
\zh
return pageSize; wR;l"*j
} #5H@/o8!s=
EXBfzK)a
publicvoid setPageSize(int pageSize){ Iewq?s\Fo
this.pageSize = pageSize; Q1jyetk~I
} s]I],>}RU
3R{-\ZMd
publicint getTotalCount(){ mdZELRu
return totalCount; qnA:[H;F
} #-@{ rgH
;8T<L[ ^U
publicvoid setTotalCount(int totalCount){ ?DRC!
9o^
if(totalCount > 0){ Ee|@l3)
this.totalCount = totalCount; >N,G@{FR
int count = totalCount / CD[7h
*jJ62-o
pageSize; VLO>{"{'
if(totalCount % pageSize > 0) kEXcEF_9P
count++; p0tv@8C>
indexes = newint[count]; Z
ZiS$&NK8
for(int i = 0; i < count; i++){ )`Fr*H3{
indexes = pageSize * mi-\PD>X
I}q-J~s
i; #E ~FF@a
} r]E$uq
bR
}else{ c3}}cFe
this.totalCount = 0; )a}5\V
} )R|7> 97
} [-CG&l2?L
-0]aOT--
publicint[] getIndexes(){ g@U#Y#b@"
return indexes; o}%fs
*
} `j(+Y
T2->
publicvoid setIndexes(int[] indexes){ $?s^HKF~
this.indexes = indexes; 2tbqmWw/s
} :J~j*_hZ
bo*q{@Ue
publicint getStartIndex(){ m!2Dk#t
return startIndex; O<E0L&4-&
} yp4G"\hN9
0GR9opZtA
publicvoid setStartIndex(int startIndex){ $e_ps~{7$
if(totalCount <= 0) Wp]EaYt2D
this.startIndex = 0; p']AXJ`Z
elseif(startIndex >= totalCount) ]S:@=9JB'
this.startIndex = indexes H|!s.
j~{2fd<>
[indexes.length - 1]; i f"v4PHq
elseif(startIndex < 0) a2 SQ:d
this.startIndex = 0; Stc\P]%d
else{ - VE#:&
this.startIndex = indexes MCCZh{uo
G!~BA*
[startIndex / pageSize]; 9=o
b:
} N\fT6#5B
} R#`itIYh
"a
g_
publicint getNextIndex(){ '
EDi6
int nextIndex = getStartIndex() +
U<t-LF3
5_`}$"<~
pageSize; em]K7B=
if(nextIndex >= totalCount) K+}Z6_:
return getStartIndex(); W"*R#:Q
else f8 jaMn9o
return nextIndex; {#%xq]r_
} Cb6MD
}-vBRY
publicint getPreviousIndex(){ y(dS1.5F
int previousIndex = getStartIndex() - W<4\4
42u\Y_^ID
pageSize; Lm?*p>\Q
if(previousIndex < 0) G4}q*&:k
return0; wgyO%
else hG@ys5
return previousIndex; `[KhG)Y7t
} LnDj
QdTe!f|
} Q#N+5<]J)#
cOb%SC[A{
mQs$7t[>t
Ig<p(G.;}
抽象业务类 @NIypi$T
java代码: eqR#`
uI2'jEjO
Q7r,5w&cm
/** 7j:{rCp3J
* Created on 2005-7-12 gp HwiFc
*/ `/zt&=`VB
package com.javaeye.common.business; %Let AR
/;4MexgB%
import java.io.Serializable; [Mz;:/
import java.util.List; =M5M;
P1wRt5
import org.hibernate.Criteria; ='0!B]<G
import org.hibernate.HibernateException; vR$5ItnT
import org.hibernate.Session; &w0=/G/T=~
import org.hibernate.criterion.DetachedCriteria; 0I((UA/7Zs
import org.hibernate.criterion.Projections; kKM%
import $at|1+bQ
udFju&!W
org.springframework.orm.hibernate3.HibernateCallback; YZl%JX
import ,7P^]V1
!P$xh
org.springframework.orm.hibernate3.support.HibernateDaoS zRu`[b3u<
dLf8w>i`T
upport; %B*dj9n^q
2-0cB$W+
import com.javaeye.common.util.PaginationSupport; mPin\-I
B:~;7A\
public abstract class AbstractManager extends <gLtX[v!CL
05B+WJ1
HibernateDaoSupport { C8:"+;
YZRB4T9
privateboolean cacheQueries = false; ts<dUO
"6yiQ\`J
privateString queryCacheRegion; Td*Oljj._U
bFezTl{M
publicvoid setCacheQueries(boolean 5V~p@vCx
6# ";W2
cacheQueries){ h&bV!M
this.cacheQueries = cacheQueries; >UY_:cW4%m
} 9M]"%E!s
W_\L_)^X
publicvoid setQueryCacheRegion(String ~C'nBV
AJfi,rFPg
queryCacheRegion){ `uVW<z{l
this.queryCacheRegion = ;6nZ
cl{W]4*$
queryCacheRegion; k_<{j0z.
} -5 /v`
~[TKVjyO
publicvoid save(finalObject entity){ L59oh
getHibernateTemplate().save(entity); |ozoc"'
} b',bi.FH
b0Ov+ )7#
publicvoid persist(finalObject entity){ `?^w
getHibernateTemplate().save(entity); rJZs
5g`
} Tki/d\!+
~88 Tz+
publicvoid update(finalObject entity){ e[mhbFf-
getHibernateTemplate().update(entity); ,'CWt]OS'
} 7&V^BW
yM:~{;HLF
publicvoid delete(finalObject entity){ h#>L:Wf5E
getHibernateTemplate().delete(entity); Hu8atlpo
} F.pHL)37
5`'=Ko,N
publicObject load(finalClass entity, 9C}aX}`
jne9=Als5
finalSerializable id){ t!~YO'<dS
return getHibernateTemplate().load |4.o$*0Y
gkML .u
(entity, id); KM}4^Qc
} )]>G,.9C}
3
9{"T0
publicObject get(finalClass entity, eM=) >zl
lzs(i2pA
finalSerializable id){ *rcuhw"^b#
return getHibernateTemplate().get S"TMsi
CKt|c!3 7
(entity, id); ESxC{
"
} nP\V1pgA
DJYXC,r
publicList findAll(finalClass entity){ !Vr45l
return getHibernateTemplate().find("from =j+oKGkoCa
$dTfvd
" + entity.getName()); 9id~NNr7
} %C`'>,t>
O
{6gNR,*
publicList findByNamedQuery(finalString !N8)C@=
zLw h6^?Y
namedQuery){ M=[q+A
return getHibernateTemplate R #3Q$
+yb$[E*
().findByNamedQuery(namedQuery); f'6qJk%J
} ^UvK~5tBV
SXBQ
publicList findByNamedQuery(finalString query, T]#,R|)d
?[S
>&Vq
finalObject parameter){ @SC-vc
return getHibernateTemplate _A,-[*OKI
Q;XHHk
().findByNamedQuery(query, parameter); O<dZA=Oez
} m-'(27
R8[iXXjku
publicList findByNamedQuery(finalString query, #i +P(xV
w
<#*O:
finalObject[] parameters){ ECS<l*i57&
return getHibernateTemplate ,/?%y\:J
!*?(Q6
().findByNamedQuery(query, parameters); O:,2OMB}B`
} P10p<@?
E]H
publicList find(finalString query){ tC?Aso
return getHibernateTemplate().find YR|(;B
W?^8/1U
(query); qXB03}] G
} ? gA=39[j
~*mOt7G
publicList find(finalString query, finalObject ci,o8 [Y
s0)qlm*
parameter){ p&OJa$N$[
return getHibernateTemplate().find V+=*2?1
=tS[&6/
(query, parameter); TDl!qp @
} xMSNrOc
yL;o{
G
public PaginationSupport findPageByCriteria hINnb7o
Q.9Ph
~
(final DetachedCriteria detachedCriteria){ jTd4 H)
return findPageByCriteria ;WvYzd9
MJ>Qq[0
(detachedCriteria, PaginationSupport.PAGESIZE, 0); of+phMev
} &ppE|[{
m0I #
public PaginationSupport findPageByCriteria q!hy;K`Jd
''(fH$pY
(final DetachedCriteria detachedCriteria, finalint 84p[N8
$kkp*3{ot
startIndex){ piYws<Q
return findPageByCriteria vLnq%@x
Q(=Vk~v
(detachedCriteria, PaginationSupport.PAGESIZE, V#gF*]q
R0Ax$Cv{
startIndex); ,5eH2W
} ;&+[W(7Sy
SRt$4EL21
public PaginationSupport findPageByCriteria V@#*``M,3
vh|Tb5W<
(final DetachedCriteria detachedCriteria, finalint 5W[3_P+
P\22op_te-
pageSize, +}c|O+6g
finalint startIndex){ jh 7p62R
return(PaginationSupport) W(uP`M%][0
Yg=E@F
getHibernateTemplate().execute(new HibernateCallback(){ Z:_m}Ya|
publicObject doInHibernate ]RH=s7L
><;l:RGK|
(Session session)throws HibernateException { i{tTUA
Criteria criteria = qJ{r!NJJ
8
_HWHQF7
detachedCriteria.getExecutableCriteria(session); 943I:, B
int totalCount = L4YVH2`0)
JCw{ ?^F"
((Integer) criteria.setProjection(Projections.rowCount (orrX Ez
e9~cBG|
()).uniqueResult()).intValue(); ~K5Cr
criteria.setProjection =bs.2aN&^
Bs+c2R
(null); v>#Cg\
List items = n!0${QVnS
[2GXAvXsT
criteria.setFirstResult(startIndex).setMaxResults M1AZ}bc0]
:DZLjC
(pageSize).list(); ; g Z%U
PaginationSupport ps = fKL'/?LD]
M&uzOK+
new PaginationSupport(items, totalCount, pageSize, GXOFk7>
l `fW{lh
startIndex); tWpl`HH
return ps; m>]>$=%
} Dk)@>l:gI,
}, true); 8ivRp<9
} :D"@6PC]
;Y
Dv.I
public List findAllByCriteria(final Ms.PO{wb
R#Y50hzT
DetachedCriteria detachedCriteria){ IXGW2z;
return(List) getHibernateTemplate [ 3$.*
=E;=+eqt
().execute(new HibernateCallback(){ \e?.hmq
publicObject doInHibernate L7SEswMti
jg~_'4f#
(Session session)throws HibernateException { {iA^rv|
Criteria criteria = CnabD{uTf
oJP<'l1
detachedCriteria.getExecutableCriteria(session); ?Wwh
_TO
return criteria.list(); x Z|&/Ci
} =y?#^
}, true); WwW"fkv
} NNwc!x)*
(N,nux(0k
public int getCountByCriteria(final )r ULT$;i@
WI,40&<
DetachedCriteria detachedCriteria){ 0(wf{5
Integer count = (Integer) fH-NU-"
j h;
9
[
getHibernateTemplate().execute(new HibernateCallback(){ (FM4 ^#6
publicObject doInHibernate @q,)fBZq
OZG0AX+=#
(Session session)throws HibernateException { 66oK3%[
Criteria criteria = zLh Fbyn(
?K0U3V$s
detachedCriteria.getExecutableCriteria(session); pp(H
PKs=}
return fk+1# 7{
s>T`l
criteria.setProjection(Projections.rowCount fCLcU@3W?
{5SfE$r
()).uniqueResult(); ft{W/ * +_
} a]`itjL^
}, true); j2M4H@
return count.intValue(); mRCHrw?WG
} %>i@F=O2<
} zCBplb
>W'j9+Va
GOGt?iw*<
>&BrCu[u
!~kEtC
?RDO] I>
用户在web层构造查询条件detachedCriteria,和可选的 _Aa[?2 O
mn.`qfMh
startIndex,调用业务bean的相应findByCriteria方法,返回一个 HCJ;&C73&
p:B
]Ft
PaginationSupport的实例ps。 G OpjRA@
Po> e kz_E
ps.getItems()得到已分页好的结果集 o"RJ.w:dn
ps.getIndexes()得到分页索引的数组 Z
#EvRC
ps.getTotalCount()得到总结果数 9x(}F<L
ps.getStartIndex()当前分页索引 [ dGO,ndE
ps.getNextIndex()下一页索引 "r@G@pe
ps.getPreviousIndex()上一页索引 U M@naU
d^tVD`Fm
*MI)]S
vEF=e
PQ,+hq
2sUbiDe-
QeL{Wa-2F
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 &RWM<6JP
KCD5*xH
,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 D%A@lMru
P 4QkY#v
一下代码重构了。 lDC}HC
g&bwtEZ
我把原本我的做法也提供出来供大家讨论吧: |ixGY^3;
b7!UZu]IEv
首先,为了实现分页查询,我封装了一个Page类: $R";
java代码: 0rcjorWI
Q? qjWZY
xo(k?+P>.
/*Created on 2005-4-14*/ l2(.>-#
package org.flyware.util.page; dN<5JQql
wk@yTTnb
/** ;|6FdU
* @author Joa 2hy NVG&$
* sYW[O"oNi
*/ [7RheXO<
publicclass Page { gGmxx,i
~Zmi(Ra
/** imply if the page has previous page */ )=Zsv40O
privateboolean hasPrePage; o_O+u%y
k Q~ %=pn
/** imply if the page has next page */ dhW<p5
privateboolean hasNextPage; (`pNXQ0n
Ra0=q4vdk
/** the number of every page */ @89I#t6A.
privateint everyPage; !y%+GwoW
jXWNHIl)@
/** the total page number */ pisB,wP$2
privateint totalPage; 7 W{~f?Sh
#d% vT!Bz~
/** the number of current page */ x<s|vgl|
privateint currentPage; n8$=f'Hgb
UW/N MjK
/** the begin index of the records by the current k-Fdj5/
gfm;xT/y
query */ [fxuUmU
privateint beginIndex; ~0ooRUWU7
k}zd'
/b
\B&6TeR
/** The default constructor */ Xem5@
(u
public Page(){ H}
6CKP}
qOi5WX6F/
}
,gmH2.
)\0q_a
/** construct the page by everyPage ec?V[v
* @param everyPage 88g47>{X
* */ }/p/pVz
public Page(int everyPage){ +0"x|$f~
this.everyPage = everyPage; KmL$M
} 87<9V.s2
#k9<
/** The whole constructor */ +#s;yc#=2
public Page(boolean hasPrePage, boolean hasNextPage, f ;wc{qy
D%U:!|G
YjLe(+WQ
int everyPage, int totalPage, q@kOTkHv)
int currentPage, int beginIndex){ B+Z13;}B
this.hasPrePage = hasPrePage; .=XD)>$
this.hasNextPage = hasNextPage; 7)J6/('
this.everyPage = everyPage; {a@>6)
this.totalPage = totalPage; q{E"pyt36R
this.currentPage = currentPage; E/mw* c^
this.beginIndex = beginIndex; `hzrfum4
} ?PH/?QP
VFSz-<L
/** N_G4_12(
* @return e:OyjG5_
* Returns the beginIndex. 6/6Rah!
*/ *b"CPg/\
publicint getBeginIndex(){ ;'HF'Z
return beginIndex; -72j:nk
} Yj|]Uff8O
x2k*|=$
/** BS7J#8cu
* @param beginIndex J>%t<xYf4
* The beginIndex to set. aD ESr?
*/ .oR3Q/|k]
publicvoid setBeginIndex(int beginIndex){ [N:BM% FQ
this.beginIndex = beginIndex; 6Y7H|>g)
} <GF @L
#6W,6(#^#
/** nU/;2=f<
* @return O!^; mhy"
* Returns the currentPage. 0^#DNq*NQ
*/ p7C!G1+z
publicint getCurrentPage(){ CCqT tp
return currentPage; WeC(w+}p
} &g0g]G21*I
I60DUuF
/** Z^#]#f
* @param currentPage ^VI,C|
* The currentPage to set. XlkGjjW#/J
*/ ia4k :\
publicvoid setCurrentPage(int currentPage){ TvQ^DZbe
this.currentPage = currentPage; !;dSC<
} FP@qh
\84v-VK
/** ^u)rB<#BR
* @return \H4U8)l
* Returns the everyPage. ~HmxEk9
*/ O>V(cmqE`
publicint getEveryPage(){ -@M3Dwsi3
return everyPage; 3.vgukkk5
} VVuR+=.&
i8~r
/** JE!("]&
* @param everyPage =_PvrB 2'
* The everyPage to set. yC
!/PQ"
*/ -$YJfQE6G
publicvoid setEveryPage(int everyPage){ XmWlv{T+
this.everyPage = everyPage; /\E [
} \c7>:DH
IU!Ht>
/** kus}WJ
* @return ;6m;M63 z
* Returns the hasNextPage. .Yx_:h=u
*/ ZL_[4Y
publicboolean getHasNextPage(){ 6y
Wc1
return hasNextPage; (oaYF+T
} 6sB$<#
aB"xqh)a}T
/** Rj6|Y"gq9
* @param hasNextPage HZZDv+
* The hasNextPage to set. nl
n OwyMJ
*/ 8Xn!Kpa
publicvoid setHasNextPage(boolean hasNextPage){ 9.&mz}q
this.hasNextPage = hasNextPage; fz}?*vPW
} uGCp#>+
:a3xvN-l
/** [B9 ;?G
* @return 'MQ%)hipA
* Returns the hasPrePage. -9o{vmB{
*/ G!Zyl^
publicboolean getHasPrePage(){ 4#)6.f~
return hasPrePage; &ao(!/im
} @Zm Jz
`ZGcgO<c\
/** 4tJa-7
* @param hasPrePage ,W*H6fw+
* The hasPrePage to set. 1 Z[f
{T)
*/ kMxjS^fr
publicvoid setHasPrePage(boolean hasPrePage){ Gvx[8I
this.hasPrePage = hasPrePage; ^Mytp> 7
} *Km7U-BG
w> 979g
/** '*R%^RK
* @return Returns the totalPage. 4%_M27bu[
* g`?:=G:a*
*/ X9XI;c;b-
publicint getTotalPage(){ [,g~m9
return totalPage; g1|w? pI1
} l[%lE
(E!!pz
/** kso*} uh0
* @param totalPage #Ufo)\x
* The totalPage to set. 213\ehhG<
*/ >Ko[Xb-8^_
publicvoid setTotalPage(int totalPage){ \=nrt?
this.totalPage = totalPage; |y1;&<
} GAl+Zg##
WzlC*iv
} I>"Ci(N
A6p`ma $L
{-WTV"L5*2
lhPGE_\
C1fyV]
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 v?j!&d>
.
/m hu
个PageUtil,负责对Page对象进行构造: (3%t+aqq
java代码: u$\a3yi
-:`V<
|~e?,[-2`r
/*Created on 2005-4-14*/ ]P1YHw9
package org.flyware.util.page; rVzI_zYqp'
)#[|hb=o
import org.apache.commons.logging.Log; t9u|iTY
f!
import org.apache.commons.logging.LogFactory; 3,6Ox45
$H*/;`,\[
/** <avQR9'&
* @author Joa tZ8e`r*
* lLiQ ;@
*/ wE Qi0!
publicclass PageUtil { FPv"N'/
&jf7k
<^
privatestaticfinal Log logger = LogFactory.getLog ]QrR1Rg
6|=j+rScv
(PageUtil.class); ];FtS>\x
%ROwr[Dj=
/** [Z<Z;=t
* Use the origin page to create a new page |NMO__l@
* @param page [1(FgyE
* @param totalRecords o`? zF+M0
* @return ,XB%\[pKe
*/ C`K^L=8`{
publicstatic Page createPage(Page page, int jP=Hf=:$
qd6fU^)i
totalRecords){ 7%d8D>uw8
return createPage(page.getEveryPage(), qX6D1X1_
I%;Jpe
page.getCurrentPage(), totalRecords); \l,rpVv5m
} 5%i:4sMx
*
<nzN $"%
/** t;O1IMF
* the basic page utils not including exception I/uy>*
8r:M*25
handler \b8\Ug~t
* @param everyPage .i/m
* @param currentPage ht6244:
* @param totalRecords vg\/DbI'
* @return page p2 ! FcFi
*/ O)#U ^
publicstatic Page createPage(int everyPage, int k`VM2+9h'^
r>n"
51*
currentPage, int totalRecords){ *e{PxaF!C
everyPage = getEveryPage(everyPage); LU2waq}VA
currentPage = getCurrentPage(currentPage); p3]Q^KFS
int beginIndex = getBeginIndex(everyPage, ;Icixu'O
5<R%H{3j
currentPage); 1W,(\'^R
int totalPage = getTotalPage(everyPage, xeA#u
J
bB6[Xj{
totalRecords); C/tr$.2H=
boolean hasNextPage = hasNextPage(currentPage, ;O=h$8]
,sQ93(Vo
totalPage); Lp&k3?W
boolean hasPrePage = hasPrePage(currentPage); :qj<p3w~}
7y<1LQ;}
returnnew Page(hasPrePage, hasNextPage, Uems\I0
everyPage, totalPage, sqO<J$tz
currentPage, 7"2b H
+4)7j&L
beginIndex); p
EusTP
} qx)?buAij
_8fA?q=
privatestaticint getEveryPage(int everyPage){ JK)qZ=
return everyPage == 0 ? 10 : everyPage; b{cU<;G)y.
} 0b-?q&*_
(q;bg1\UK
privatestaticint getCurrentPage(int currentPage){ ;hDa@3|]34
return currentPage == 0 ? 1 : currentPage; <+U|dX
} _D;@v?n6!O
*@S@x{{s
privatestaticint getBeginIndex(int everyPage, int ^vni&sJ
wEEn?
currentPage){ WFv!Pbq,
return(currentPage - 1) * everyPage; L^0v\
} +t!S'|C
0kDBE3i#
privatestaticint getTotalPage(int everyPage, int QU5Sy oL[
>fs2kha
totalRecords){ iEHh{H(
int totalPage = 0; f~h~5
Y`ihi,s`H
if(totalRecords % everyPage == 0) "v]%3i.*
-
totalPage = totalRecords / everyPage; Z~u9VYi!
else uO(w1Q"^
totalPage = totalRecords / everyPage + 1 ; B!S 167Op
)u} Q:`9
return totalPage; {=Q7m`1
} _GA$6#]
( [E]_Q
privatestaticboolean hasPrePage(int currentPage){ A o/vp-e
return currentPage == 1 ? false : true; Z S|WnMH
} M"Y0jQ(
$P {K2"Oc
privatestaticboolean hasNextPage(int currentPage, ]\c,BWC@e
\vbk#G
hH
int totalPage){ F:g= i}7
return currentPage == totalPage || totalPage == c:4P%({
_eQ-`?
0 ? false : true; E`;;&V q-
} 5J.0&Dda
)e%}b-I'r
|D#2GeBw1h
} MQTdk*L_]
{7"0,2 Hb?
cDkV;$
N$I03m
6d|q+]x_n
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。 5LW}h^N
! fl4"
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 p9[6^rjx8
>s EjR!
做法如下: ql{_%x?
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 L8$1K &!
Ib`-pRU;
的信息,和一个结果集List: #bnb': f
java代码: b{Zpux+
b$JBL_U5Ch
3=.Y,ENM;
/*Created on 2005-6-13*/ On_@HQ/FI
package com.adt.bo; B(5c9DI`
]N)DS+V/
import java.util.List; 't (O$
kuMKX`_
import org.flyware.util.page.Page; 1Y/$,Oa5
\Sy7"a
/** _t>"5s&i
* @author Joa )}lRd#V
*/ ^))RM_ic
publicclass Result { p<GR SJIk=
v! hY
private Page page; zqySm)o]
F2I 5qC/
private List content; Fd$!wBL
QfpuZEUK
/** Hh[Tw&J4
* The default constructor ]!"S+gT*C
*/ Y%`SHe7M
public Result(){ Z*!O:/B
super(); JgfVRqm
} Djt%r<
3{7T4p.G
/** &%=D \YzG
* The constructor using fields 7'p8a<x
* 5]Da{Wmgs
* @param page .IrNa>J~
* @param content 4vZ4/#(x
*/ #?O&
public Result(Page page, List content){ 9(_{`2R8
this.page = page; #;VA5<M8
this.content = content; /Ft:ffR|R
} J
m{
^_5|BT@
/** n(ir[w#,]"
* @return Returns the content. EMvHFu
*/ ,XKCz ]8V
publicList getContent(){ sH#X0fG
return content; B|Wk?w.{r\
} : 3ZYJW1
b'p4wE>
/** "jg@w%~
* @return Returns the page. " {dek
*/ #CUzuk&
public Page getPage(){ QV|>4 ^1D
return page; 1+kE!2b;b
} C"uahP[Y
Y$
Fj2nk+
/** .8gl< vX
* @param content f i~I@KJ>
* The content to set. ]wn/BG)
*/ N;sm*+r
public void setContent(List content){ QrYa%D+
this.content = content; eCbf9B
} p^)B0[P9
]1`g^Z@ 0
/**
WY
* @param page [j,txe?n
* The page to set. Yg|lq9gD
*/ -#:zsu
publicvoid setPage(Page page){ vRQOs0F;
this.page = page; K|S:{9Q
} 48D?'lW %
} >7Jr^o#|_x
EM j;2!
Fzq41jiS
"eAy^,
5N7H{vT_
2. 编写业务逻辑接口,并实现它(UserManager, D/(CU#i"
*#U+qgA;`
UserManagerImpl) b{M7w
java代码: n`7f"'/:
-1|iz2^N
+JyUe
/*Created on 2005-7-15*/ TbVn6V'
package com.adt.service; R*pC.QiB~
1QqHF$S
import net.sf.hibernate.HibernateException; 4$6T+i2E
T?
,P*l
import org.flyware.util.page.Page; 95W?{>
@
h11.'Eej`
import com.adt.bo.Result; %b2oiKSBx?
r{?TaiK
/** LaMLv<)k
* @author Joa _~'+Qe_o$5
*/ <PN"oa#
publicinterface UserManager { +_l^ #?o,
9nSWE W
public Result listUser(Page page)throws wBk@F5\<
}YhtUWz].
HibernateException; DPn=n9n2
C#pZw[
} >ezi3Zx^
5II(mSg8
Ard]147
=}!Mf'
#uCB)n&.
java代码: o(kM9G|
E6B!+s!]
9O.Y OiW
/*Created on 2005-7-15*/ uGN^!NG-0
package com.adt.service.impl; XM1`x
0IkM
import java.util.List; RJeDEYXeg
Z"-L[2E/{!
import net.sf.hibernate.HibernateException; ~V=<3X
>x1p%^cA;=
import org.flyware.util.page.Page; aolN<u3G
import org.flyware.util.page.PageUtil; KW^<,qt5w
{svn=H
/
import com.adt.bo.Result; Y/ot3[
import com.adt.dao.UserDAO; WG71k8af
import com.adt.exception.ObjectNotFoundException; SO\/-]9#
import com.adt.service.UserManager; Q^Ql\
kzmQm
/** I`(l *U
* @author Joa az;Q"V'6
*/ oEz%={f
publicclass UserManagerImpl implements UserManager { /t<@"BoV
D('2p8;2"7
private UserDAO userDAO; 1nknSw#
U5HKRO
/** HmmS(fU
* @param userDAO The userDAO to set. g9fq5E<G
*/ `Hx~UH)
publicvoid setUserDAO(UserDAO userDAO){ @wmi5oExc
this.userDAO = userDAO; t>)45<PEw
} qSCv )S(
BKa-
k!
/* (non-Javadoc) &)F*@C-
* @see com.adt.service.UserManager#listUser ikB Yd
}5
G$zL)R8GE|
(org.flyware.util.page.Page) f$HH:^#
*/ 2I1uX&g
public Result listUser(Page page)throws NG&_?|OmV
2Se?J)MN
HibernateException, ObjectNotFoundException { 7IlOG~DC
int totalRecords = userDAO.getUserCount(); T^<>Xiam
if(totalRecords == 0) %?C8mA'w
throw new ObjectNotFoundException 3Ug
69y;`15
("userNotExist"); S{Hx]\
page = PageUtil.createPage(page, totalRecords); gy:%l
List users = userDAO.getUserByPage(page); g.JN_t5
returnnew Result(page, users); x"P);su
} ?rX]x8iP
HS>f1!
} X@)z80
C`jM0Q
;^Sr"v6r>u
(m[bWdANnW
(UCK;k
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 Qcjc,
x3ERCqTR
询,接下来编写UserDAO的代码: dx*qb
3. UserDAO 和 UserDAOImpl: YNrp}KQ
java代码: J/!cGr(B~
h_d +$W5
4F3x@H'
/*Created on 2005-7-15*/
'uDjFQX
package com.adt.dao; J~B
7PW
RE$`YCs5
import java.util.List; )&{K~i ;:
8x{B~_~
import org.flyware.util.page.Page; D<i[LZd
Fk;oE'"D
import net.sf.hibernate.HibernateException; )QagS.L{z
Syp"L;H8Em
/** 7r+g8+4
* @author Joa ZI;<7tF_z
*/ hd V1nS$
publicinterface UserDAO extends BaseDAO { tGdf/aTjy
;< )~Y-
publicList getUserByName(String name)throws oY~ Dg
Q zZ;Ob]'
HibernateException; Z4$cyL'$P
[
=x s4=
publicint getUserCount()throws HibernateException; Rv,JU6>i
I
V%VU
publicList getUserByPage(Page page)throws /y7M lU9
9mc!bj^811
HibernateException; R2L;bGI*J
8mLP5s!7
} |wEN`#.;b
o'~5pS(wq
;|p$\26S)%
g[>\4B9t
Uawpfgc}
java代码: "N:XzG
l JP1XzN_
@;xMs8@
/*Created on 2005-7-15*/ yL^UE=#C_
package com.adt.dao.impl; +`M!D }!
LWsP ya
import java.util.List; f=!PllxL:
CxhY$%C (L
import org.flyware.util.page.Page;
d8SE,A&
m\>a,oZH
import net.sf.hibernate.HibernateException; rKHY?{!
import net.sf.hibernate.Query; Fhz*&JC#
l:6,QaT1
import com.adt.dao.UserDAO;
@=]~\[e\
}u+a<:pkK
/** 6<,dRn
* @author Joa m]_FQWfet
*/ qQi.?<d2"s
public class UserDAOImpl extends BaseDAOHibernateImpl thO ~=RB
Ko&hj XHx
implements UserDAO { .I VlEG0
3bqC\i^[\m
/* (non-Javadoc) m+{K^kr[
* @see com.adt.dao.UserDAO#getUserByName =@u 5|:
z|7zj/+g
(java.lang.String) ~m1P_`T
*/ b96%")
publicList getUserByName(String name)throws B()/.w?A
"xMD,}+5$$
HibernateException { 1Kvx1p
String querySentence = "FROM user in class i`/+,<
b5m=7;u*h
com.adt.po.User WHERE user.name=:name"; .,~(%#Wl$
Query query = getSession().createQuery G1t\Q-|l0
p_ Fy>j
(querySentence); ]Q
"p\@\!
query.setParameter("name", name); wi8Yl1p]!z
return query.list(); }~h'FHCC+
} 6~#Ih)K
HIGq%m=-x
/* (non-Javadoc) q1y/x@
* @see com.adt.dao.UserDAO#getUserCount() 3'c\;1lhT
*/ M@P1, Y
publicint getUserCount()throws HibernateException { 7f<EoSK
int count = 0; {:c]|^w6
String querySentence = "SELECT count(*) FROM k+V6,V)my
FLoNE>q
user in class com.adt.po.User"; /!}'t
Query query = getSession().createQuery 04J}UE]Ww
2#X4G~>#h
(querySentence); n\I#CH0V
count = ((Integer)query.iterate().next e&MC|US=\
(qn2xrV
()).intValue(); ;v17K
return count; +6smsL~<#v
} k"kJ_(
I9o6k?$K
/* (non-Javadoc) bW#@OrsS
* @see com.adt.dao.UserDAO#getUserByPage wiOgyMdx
Y=Z1Tdxa|
(org.flyware.util.page.Page) 'tN25$=V&W
*/ iDl;!b&V.
publicList getUserByPage(Page page)throws AeIrr*~]B
Vh3Ijn
HibernateException { &Gm$:T'~
String querySentence = "FROM user in class +,:^5{9{
Rj~
com.adt.po.User"; w(L>#?
Query query = getSession().createQuery ^1:U'jIXO
oIGrA-T}
(querySentence); ~zm7?_"@]
query.setFirstResult(page.getBeginIndex()) #X:
'aj98
.setMaxResults(page.getEveryPage()); D3Jr3
%>
return query.list(); 53HU.
} =k3!RW'
%2'A
pp
} x\?;=@AW
|o'Q62`%}
KPSh#x&I
c8)/:xxl
*BD=O@
至此,一个完整的分页程序完成。前台的只需要调用 1\RGM<q$f
M:Er_,E
userManager.listUser(page)即可得到一个Page对象和结果集对象 n}A\2bO
$&|y<Y=
的综合体,而传入的参数page对象则可以由前台传入,如果用 rzrl>9
h
}}QT HR
webwork,甚至可以直接在配置文件中指定。 OE)~yKy
?EMK8;
下面给出一个webwork调用示例: bG&"9b_c
java代码: }14{2=!Q
$=sXAK9
IUGz =%[
/*Created on 2005-6-17*/ A>VI{
package com.adt.action.user; ?6Cz[5\
[=uo1%
import java.util.List; DfJ2PX}q
d#:3be{|&q
import org.apache.commons.logging.Log; %zC[KE*~
import org.apache.commons.logging.LogFactory; SgMrce<;
import org.flyware.util.page.Page; HQ9f ,<
F Kc;W
import com.adt.bo.Result; #5sD{:f`
import com.adt.service.UserService; bLz*A-
import com.opensymphony.xwork.Action; kH*P n'
*IlaM'[*
/** yTE%hHH]&[
* @author Joa aYL|@R5;e
*/ Gy1xG.yM~
publicclass ListUser implementsAction{ u^I(Ny
RO\gax
privatestaticfinal Log logger = LogFactory.getLog R8*Q$rH<
]"AyAkT(
(ListUser.class); QVZD/shq
d
"BW/%m|g
private UserService userService; z!=P@b
_|<d5TI
private Page page; J
)BI:]m
Y9SGRV(
privateList users; (VyNvB
v8>v.}y
/* ->-*]-fv[L
* (non-Javadoc) Ot&:mT!2
* YF#HSf7
* @see com.opensymphony.xwork.Action#execute() F0~k1TDw
*/ l>lW]W
publicString execute()throwsException{ ]!1OH
|Ad
Result result = userService.listUser(page); +ww^ev%
page = result.getPage(); K*K1(_x=
users = result.getContent(); 5_K5?N
return SUCCESS; F}Mhs17!|
} Jsg
I'
;S$Ll*f>D
/** 5yh/0i5 |
* @return Returns the page. JnD{J`:
*/ &a> lWE
public Page getPage(){ Y izE5[*
return page; >Sk[vI0Y
} #)+- lPe
2J;`m_oP
/** RKd
* @return Returns the users. CozKyt/r7
*/ W!$zXwY}(
publicList getUsers(){ UbJ*'eoX
return users; Qz<d~N
} wbbqt0un
hRaf#
/** l2v_?j-)x
* @param page FHy76^h>e
* The page to set. pvWau1ArNq
*/ Hyk'c't_O
publicvoid setPage(Page page){ ;SwC&.I
this.page = page; >Dm8m[76
} q)u2Y]
@b&84Gn2
r
/** 3K/Df#
* @param users ske@uzAz
* The users to set. I"L;L?\S
*/ $X`y%*<<v
publicvoid setUsers(List users){ CF
y}r(q
this.users = users; $KV&\Q3\0
} <x%M3BTx
Dkw%`(Oh/,
/** O[~x_xeW
* @param userService ClW'W#*(Y
* The userService to set. 2)iD4G`
*/ uE_c4Hp
publicvoid setUserService(UserService userService){ xc
1A$EY
this.userService = userService; jX=lAs~6
} @
$cUNvI
} AH7L.L+$M
.;/L2Jv
S^RUw
qG8s;_G
r >{G`de4
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, v vu<:16
2f, B$-#
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 -xmf'c9P
TT!ET<ciN
么只需要: *}b]rjsj
java代码: hP?fMW$V
^~ =9
~9pM%N
V
<?xml version="1.0"?> l?N`{,1^
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork >.9eBz@
%(m])
1.0//EN" "http://www.opensymphony.com/xwork/xwork- I d8wS!W`7
(ClhbfzD
1.0.dtd"> V}8$p8#<@
#m. AN
<xwork> eBB:~,C^q.
D=?{8 'R'
<package name="user" extends="webwork- oT+(W,G
+`en{$%%
interceptors"> wJ"ev.A)
=6 %|?5G
<!-- The default interceptor stack name |g)FA_#|<
N$aZ== $5
--> uF(k[[qaiN
<default-interceptor-ref [5ethM
9G+f/k,P
name="myDefaultWebStack"/> =Z0t :{
% +Pl+`?E
<action name="listUser" e29y7:)c=
.CV _\
class="com.adt.action.user.ListUser"> ^tAO_~4
<param AY2:[ 5cm
Fxd{ Zk`
name="page.everyPage">10</param> zok D:c
<result mMw;0/n
eMMx8E)B
name="success">/user/user_list.jsp</result> pu;3nUH
</action> 9Ld9N;rWm#
<bmLy_":
</package> h* .w"JO
y%(X+E"n*
</xwork> O&?.&h
=V $j6
gp
#!#z5DJu
"e62/Ejg%
`7Ug/R<
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 1$LI px
crmUrF#
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。 ~t/JCxa
Hhv$4;&X
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 hY;_/!_
8[5|_Eh+
$C_M&O}
PnWD}'0V
WYIw5jzC
我写的一个用于分页的类,用了泛型了,hoho z]#hWfM4B:
SE `l(-tL
java代码: (O5)wej
`.BR=['O
ia{kab|_5
package com.intokr.util; T!^Mvat
}=GM?,7b
import java.util.List; Ti= 3y497S
" ~$$
/** 1kFjas`g
* 用于分页的类<br> R_e)mkE
* 可以用于传递查询的结果也可以用于传送查询的参数<br> g()m/KS<
* xPQL?.
* @version 0.01 R{3CW^1
* @author cheng bEpMaBN
*/ LpWI>sNv
public class Paginator<E> { R2^iSl%pj
privateint count = 0; // 总记录数 k/`i6%F#m
privateint p = 1; // 页编号 <MZi<Z`
privateint num = 20; // 每页的记录数 'U)8rR
privateList<E> results = null; // 结果 P^IY:
-s
%g^"]
/** sbla`6Fb
* 结果总数 Yo2Trh
*/ tV`&-H
publicint getCount(){ Pz473d
return count; {'~sS
} 'j79GC0
%W;u}`
publicvoid setCount(int count){ c^S&F9/U*
this.count = count; |9s wZ[
} &'O?es|Lb
I'IB_YRL4
/** !<Z{@7oH
* 本结果所在的页码,从1开始 a$+#V=bA
* @d)a~[pm
* @return Returns the pageNo. f5?hnt`m
*/ ?)cJZ>$!w
publicint getP(){ ,L%p
return p; @hT;Bo2G]
} < l[`"0
V\zsDP
/** `^%GN8d}nm
* if(p<=0) p=1 "6V_/u5M;=
* lG]GlgSs
* @param p WEC-<fN|Y\
*/ |h,FUj<r
publicvoid setP(int p){ oQvFrSz
if(p <= 0) A?Sm-#n{
p = 1; RndOm.TE
this.p = p; qJMp1DC
} ` u=<c
h.b+r~u
/** >B~?dT m
* 每页记录数量 s1=u{ET
*/ '3%*U*I
publicint getNum(){ Oxn'bh6R0
return num; r5)f82pQ
} A_Gp&acs$
=g2\CIlVU6
/** XI
g|G}i.
* if(num<1) num=1 h544dNo&
*/ Kq6qXc\x
publicvoid setNum(int num){ WguV{#=H
if(num < 1) 6DZ2pT:
num = 1; a}D&$yz2
this.num = num; ro]L}oE+
} APuu_!ez1
`q1}6U/k
/** ?M<|r11}
* 获得总页数 uN&M\(
*/ =+Tsknq
publicint getPageNum(){ )`RZkCe
return(count - 1) / num + 1; fiqj;GW
} ^z?=?%{
R7t
bxC
/** "0Y&~q[=
* 获得本页的开始编号,为 (p-1)*num+1 "GB UQ}
*/ +2(PcJR~
publicint getStart(){ .Bijc G
return(p - 1) * num + 1; mg/]4)SF
} F\P!NSFZV
A?V<l<EAm
/** faJ8zX
* @return Returns the results. Z{16S=0
*/ 73#9NZR
publicList<E> getResults(){ {lKEZirO
return results; -9i+@%{/
} :\T_'Shq
/K&