Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 nQ/R,+6h
ZgN )sVJ
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 87Sqs1>cw
cr{;gP
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 +ht -Bl
<<zYF.9L]
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 KaJCfu yp
w`kn!k8
。 e12.suv
V^a]@GK:
分页支持类: LV4]YC
0] 'Bd`e
java代码: a9CY,+z5B
XwKB+Yj0
}u=-Y'!#]
package com.javaeye.common.util; ]V,wIyC
Sga/i?!
import java.util.List; B 4pJg
Voi`OCut
publicclass PaginationSupport { S\"/=|\
ZGUhje!
publicfinalstaticint PAGESIZE = 30; G+^Q
_w
VP|ga}(
privateint pageSize = PAGESIZE; EkV
LSur
#K8kz
privateList items; aKkG[qN
>4gGb)
privateint totalCount; CNCWxu
Cv@ZzILyoK
privateint[] indexes = newint[0]; .w/_Om4T*b
uyt]\zVT
privateint startIndex = 0; ]]
R*sd*
?0>%
a$`
public PaginationSupport(List items, int (Kl96G<Wej
<r_L-
totalCount){ ~_SoP
setPageSize(PAGESIZE); K5O8G
setTotalCount(totalCount); _ lrCf
setItems(items); :wn9bCom?M
setStartIndex(0); f%Y'7~9bA
} a?4'',~
Nwu, :}T
public PaginationSupport(List items, int ={[s)G
ZXP9{Hh
totalCount, int startIndex){ 3g!tk9InG
setPageSize(PAGESIZE);
UADD 7d
setTotalCount(totalCount); oMH-mG7:K
setItems(items); :J|t! `
setStartIndex(startIndex); F]e]
} =-XI)JV#
0{0|M8
public PaginationSupport(List items, int ')kn
o1x IGP<
totalCount, int pageSize, int startIndex){ Q/oe l'O*x
setPageSize(pageSize); 3<ikMUq&
setTotalCount(totalCount); 7B@[`>5?%L
setItems(items); 1'c
setStartIndex(startIndex); 0_d,sC?V
} )/BI:)
jmgU'w-s
publicList getItems(){ NwH`t#zd
return items; s8,{8k
} %:bTOw[4r
][b_l(r$?
publicvoid setItems(List items){ AV"fOK;#A
this.items = items; v%_5!SR
} 0/7y&-/(
zJE$sB.f
publicint getPageSize(){ Bvke@|]kW
return pageSize; Q{ hXP*5
} 1bW[RK;GE
\`:X37n)0q
publicvoid setPageSize(int pageSize){ 2&st/y(hs
this.pageSize = pageSize; %#!pAUP\&
} %d..L-`]ET
>'>onAIL
publicint getTotalCount(){ [D[&aA
return totalCount; Z^AOV:|m
} 5^"T`,${
}!tJ3G
publicvoid setTotalCount(int totalCount){ `mN*"1p-
if(totalCount > 0){ =|lw~CW
this.totalCount = totalCount; ?]i.Zi\[f
int count = totalCount / so~vnSQ!x
4CR.=
pageSize; 86[/NTD<-
if(totalCount % pageSize > 0) ,2H@xji
[
count++; :JBvCyj4PE
indexes = newint[count]; RQzcsO
for(int i = 0; i < count; i++){ rQ0V3x1"Qx
indexes = pageSize * *XRAM.
?LP&VU1
i; 7_,)"J2^
} "c[ D0{\{
}else{ uWs5+
this.totalCount = 0; >EQd;Af
} }]0f -}
} 9mdp\A
h?f)Bt}ry
publicint[] getIndexes(){ h{ s- e.
return indexes; j7&57'
} $ b Q4[
C]22 [v4
publicvoid setIndexes(int[] indexes){ x.Sq2rw]V
this.indexes = indexes; oz!;sj{,D
} R)s@2S
{1H3VSYq
publicint getStartIndex(){ Jg I+k Nx
return startIndex; 5ZG-3qj
} JGS4r+
`^t0379e
publicvoid setStartIndex(int startIndex){ 3*13XQ
if(totalCount <= 0) 9(.P2yO
this.startIndex = 0; 4~<
:Pj
elseif(startIndex >= totalCount) -"u9s[L{
this.startIndex = indexes ; Drt4fOxX
-p|@En n
[indexes.length - 1]; .Rq|F
elseif(startIndex < 0) Jf<+VJ>t
this.startIndex = 0; L;a>J
else{ -]1F]d
this.startIndex = indexes }@-4*5P3
/b *VFA/75
[startIndex / pageSize]; 6qsT/
} 2jQ|4$9j
} h= uv4&
-J?i6BHb
publicint getNextIndex(){ 7<W7pXDp
int nextIndex = getStartIndex() + <VB;J5Rv
xngK_n
pageSize; zY@|KV"^r
if(nextIndex >= totalCount) 1b)^5U ;
return getStartIndex(); :OC`X~}Rc
else ulM6R/V:?
return nextIndex; i#$N,kt
} 92}UP=RW!
a0y7a/@c
publicint getPreviousIndex(){ V,=V
int previousIndex = getStartIndex() - F<wwuCbF
&lg+uK
pageSize; K2J DG.<
if(previousIndex < 0) 6PETIs
return0; /aa'ryl_%
else @/6cEiC+r\
return previousIndex; Go>_4)jy
} jPG&Ypm1
Q_<CG[,6D1
} X(m&
U0}]3a0
4%#C _pE9
r"s
<;
抽象业务类 $i@~$m7d-
java代码: s'yA^
VPf
2"
(vjnfH
] -O/{FIv
/** F?]nPb|
* Created on 2005-7-12 ejYJOTT{^
*/ i*`; /x'+
package com.javaeye.common.business; w{$t:l)2,
Gq4~9Tm)*
import java.io.Serializable; FyuCYg
\p
import java.util.List; @}&o(q1M0
>mzK96
import org.hibernate.Criteria; 2J;h}/!H
import org.hibernate.HibernateException; Q/T\Rr_d
import org.hibernate.Session; 9;3f`DK@2k
import org.hibernate.criterion.DetachedCriteria; [([?+Ouy
import org.hibernate.criterion.Projections; :(A5,$
import S?.2V@Ic
ZRYs7 4<
org.springframework.orm.hibernate3.HibernateCallback; uVJ;1H!
import eup#.#J
]kC/b^~+m
org.springframework.orm.hibernate3.support.HibernateDaoS *Q bPz4,"
^J0*]k%
upport; YKbR#DC\
;5 W|#{I
import com.javaeye.common.util.PaginationSupport; OA#AiQUR
mgeNH~%m@*
public abstract class AbstractManager extends KL]@y!QU
d,j"8\@
HibernateDaoSupport { ?`?"j<4e
;kO
Op@e
privateboolean cacheQueries = false; Lx&2)
3rX5haD\
privateString queryCacheRegion; c!@g<<}[(
8E`rs)A
publicvoid setCacheQueries(boolean .%>UA|[~:
kb>:M.
cacheQueries){ Q5'DV!0aSv
this.cacheQueries = cacheQueries; 6AgevyVG
} 3{o5AsVv
hamn9
publicvoid setQueryCacheRegion(String vluA46c
ol^J-
queryCacheRegion){ P@LYa_UFsN
this.queryCacheRegion = 56(S[
XBv:$F.>$
queryCacheRegion; 8/Z
} Nq>74q]}n8
Ct[{>asun
publicvoid save(finalObject entity){ xcO Si>
getHibernateTemplate().save(entity); m_~!Lj[u.
} :Mr _/t2(
xk=5q|u_-
publicvoid persist(finalObject entity){ yRaB\'
getHibernateTemplate().save(entity); T1ZAw'6(K
} b!VaEK
9j458Yd4*
publicvoid update(finalObject entity){ E.kGBA;a?
getHibernateTemplate().update(entity); MH|!tkW>:
} ES72yh]
`mV&[`NZ
publicvoid delete(finalObject entity){ i,>yIPBU!
getHibernateTemplate().delete(entity); B5"(NJ;
} ^]}UyrOn
|<&9_Aq_
publicObject load(finalClass entity, [>xwwm
[ h7nOUL!
finalSerializable id){ b`N0lH.V
return getHibernateTemplate().load YUdCrb9F
8:c[_3w
(entity, id); 1au1DvH
} "\bbe @
Y9fktg.
publicObject get(finalClass entity, gV]]?X&
LU5e!bP
finalSerializable id){ !MoJb#B3^]
return getHibernateTemplate().get t-gg,ttnA
p
b:mw$XQ7
(entity, id); YX38*Ml+V
} dXgj
ML?%s`
publicList findAll(finalClass entity){ e
W&;r&26
return getHibernateTemplate().find("from gZ6]\l]J{
uev$5jlX
" + entity.getName()); o9-b!I2
} BE/#=$wPjM
[r%WVf.#d
publicList findByNamedQuery(finalString n@[&SgZq
1ipfv-hb6
namedQuery){ Hm@+(j(N96
return getHibernateTemplate k4iu`m@^H
WT$m*I
().findByNamedQuery(namedQuery); i8A{DMc,U
} ZaQgSE>Y
:X-Z|Pv8
publicList findByNamedQuery(finalString query, Fl\X&6k
Z3E957}
finalObject parameter){ ^Nl)ocHv!
return getHibernateTemplate *het_;)+{
qB-9&X
().findByNamedQuery(query, parameter); M^I*;{w6i
} J+IQvOn_|
46c7f*1l
publicList findByNamedQuery(finalString query, BU-+L}-48
ZzET8?8
finalObject[] parameters){ EMME?OW$
return getHibernateTemplate ^LgaMmz
X6s6fu;
().findByNamedQuery(query, parameters); a-\\A[E
} qa
'YZE`
p?S:J`q
publicList find(finalString query){ e R"XXF0u
return getHibernateTemplate().find K2PV^Y
Q7oJ4rIP
(query); <I
.p{Z
} rJi;"xF8
2*:lFvwP
publicList find(finalString query, finalObject 1jU<]09.
$!P(Q
parameter){ Z(LDAZG
return getHibernateTemplate().find VP^Yph 8R
"4N%I
(query, parameter); .),%S}
} EIO!f[]o
J~7E8
public PaginationSupport findPageByCriteria v%c r
$P#Cf&R
(final DetachedCriteria detachedCriteria){ Wlm%W>%
return findPageByCriteria k{>rI2;
QA_SS'*
(detachedCriteria, PaginationSupport.PAGESIZE, 0); v#u]cmI
} vaQZ1a,
HPVW2Y0_N
public PaginationSupport findPageByCriteria o3*IfD
.sNUU 3xSC
(final DetachedCriteria detachedCriteria, finalint 9!sx
jR<yV
startIndex){ `M?C(
return findPageByCriteria c|q!C0X[
yU"lW{H@
(detachedCriteria, PaginationSupport.PAGESIZE, IxC/X5Mp^q
3\FPW1$i|[
startIndex); *yp}#\rk
} Pe@M_ r
Hm2}xnY
public PaginationSupport findPageByCriteria 41 sClC"
~J1;Z0}#
(final DetachedCriteria detachedCriteria, finalint ^)=c74;;
]UyIp`nV;
pageSize, Qo+_:N
finalint startIndex){ pjr,X+6o
return(PaginationSupport) yP2[!vYw
%m[
:},
getHibernateTemplate().execute(new HibernateCallback(){ J0xOB;rd
publicObject doInHibernate _urv
We
]Cy1yAv={
(Session session)throws HibernateException { aH<BqD[#
Criteria criteria = Di{T3~fqU
JzH\_,,
detachedCriteria.getExecutableCriteria(session); 0KqG J:Ru
int totalCount = '/+l\.z"&
D&_Ir>"\
((Integer) criteria.setProjection(Projections.rowCount !FOPFPn
OD5c,IkWB
()).uniqueResult()).intValue(); z:f[<`,GT
criteria.setProjection tK)E*!
h-`Jd>u"
(null); w6>'n
}
List items = X}b%gblx
Q`ERI5b6
criteria.setFirstResult(startIndex).setMaxResults c]jK
Y<
e|Iylv[3
(pageSize).list(); ^6;n@
PaginationSupport ps = m#Rgelhk.
'c[4-m3bg
new PaginationSupport(items, totalCount, pageSize, q%8%J'Fro
TTcMIMyLT
startIndex); -+4:}
sD
return ps; ($:s}_<>s
} dK|6p_
}, true); ")kE1D%
} clK3kBh~&
`oN~
public List findAllByCriteria(final w^tNYN,i
lC&U9=7W
DetachedCriteria detachedCriteria){ un|+YqLf
return(List) getHibernateTemplate 9?B}CCE<LR
FNlzpCT~L
().execute(new HibernateCallback(){ 6LZ(bP'd;
publicObject doInHibernate ]CyWL6z
NYtp&[s2-
(Session session)throws HibernateException { s>d@=P>R
Criteria criteria = $
hwJjSZ0
O57n<J'6
detachedCriteria.getExecutableCriteria(session); =fa!"$J3
return criteria.list(); e#0C
} j>XM+>
}, true); bnBnE[y<'
} !7ct=L
+r[u4?
public int getCountByCriteria(final &L}e&5
0-#SvTf>;:
DetachedCriteria detachedCriteria){ [eL?O;@BD
Integer count = (Integer) 0eq="|n^|
2= FGZa*.
getHibernateTemplate().execute(new HibernateCallback(){ fk-zT
publicObject doInHibernate W6f?/{Oo8
n%PHHu
(Session session)throws HibernateException { K~gt=NH
Criteria criteria = i)fAm$8#G
'6i"pJ0%
detachedCriteria.getExecutableCriteria(session); 7z!|sPW](b
return Y$SZqW0!/
hMz= \)Pl
criteria.setProjection(Projections.rowCount +e_NpC
_?Zg$7VJ
()).uniqueResult(); > ?s[g)np
} 4UD7!
}, true); >mRA|0$
return count.intValue(); :lz@G4=C
} KP"
lz
} a$!|)+
*BzqAi0
d
dB}mk6
)s^D}I(
EjLj5Z/q
zs!,PQF(
用户在web层构造查询条件detachedCriteria,和可选的 .G#wXsJj
\{
startIndex,调用业务bean的相应findByCriteria方法,返回一个 ;&4}hPq
&~oBJar
PaginationSupport的实例ps。 d`9%:2qE
wi/Fx=w
ps.getItems()得到已分页好的结果集 ; V)pXLE
ps.getIndexes()得到分页索引的数组 ]pi"M3f_
ps.getTotalCount()得到总结果数 n'a=@/
ps.getStartIndex()当前分页索引 JK:i-
ps.getNextIndex()下一页索引 Lqy]bnY
ps.getPreviousIndex()上一页索引 $ )q?z.U
T+p?VngF
1,,kU
#7/;d=
dH"wYMNL
?&?gQ#\N_J
Hq'mv_}qG
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ( 0/g)gW
%>^CD_[eO
,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 RWM9cV5
Rn6;@Cw
一下代码重构了。 %9ef[,WT
tA'O66.
我把原本我的做法也提供出来供大家讨论吧: |uT|(:i84,
O>UG[ZgW
首先,为了实现分页查询,我封装了一个Page类: &u)
R+7bl,
java代码: #&zNYzI
?K]Cs&E4
'J(rIH3U
/*Created on 2005-4-14*/ $<R\|_6J
package org.flyware.util.page; M6J~%qF^
$g? ]9}p
/** :D(4HXHK%
* @author Joa W@<(WI3
* e<wA["^
*/ C-Y~T;53
publicclass Page { @H%)!f]zWt
`)e5pK
/** imply if the page has previous page */
hUy"XXpr
privateboolean hasPrePage; 82ay("ZY
HD^ Ou5YB
/** imply if the page has next page */ f5p>oXo4b
privateboolean hasNextPage; Pi|WOE2
;"/[gFD5u
/** the number of every page */ C+\c(M a
privateint everyPage; UYJMW S=
M*ZR+pq,
/** the total page number */ )`;Q]?D
privateint totalPage; c^ $_epc*
LLE\ ;,bv
/** the number of current page */ x'dU[f(
privateint currentPage; ;!H<W[
R+vago:
/** the begin index of the records by the current D; xRgHn
N]gJ(g
query */ hgt@Mb
privateint beginIndex; /SDN7M]m!
-Zs.4@GH
h RK&
/** The default constructor */ g}(yq:D
public Page(){ V`*N2ztSL
AAbI+L0m{
} B",5"'id
9t)A_}O
/** construct the page by everyPage 88%7
* @param everyPage |C;8GSw>|F
* */ uL!QeY>k\
public Page(int everyPage){ oSd TQ$U!D
this.everyPage = everyPage; @~t^zI1
} 1Pya\To,m
_:(RkS!x
/** The whole constructor */ OR84/^>
public Page(boolean hasPrePage, boolean hasNextPage, 2% ],0,o
./SDZ:5/
xi5G?r
int everyPage, int totalPage, Da.eVU;
int currentPage, int beginIndex){ U$zd3a_(
this.hasPrePage = hasPrePage; vTE3-v[i
this.hasNextPage = hasNextPage; kD_Ac{{<
this.everyPage = everyPage; Y#aL]LxZE
this.totalPage = totalPage; }_,\yC9F
this.currentPage = currentPage; Vl"20):
this.beginIndex = beginIndex; <%d/"XNg[D
} |"}F cS
y
Vf28R,~m
/** MR")
* @return rw:z|-r
* Returns the beginIndex. N{/):O
*/ 6-"@j@l5<
publicint getBeginIndex(){ Vr/UY79
return beginIndex; (2 nSZRB
} EI+RF{IKh
"==fWf
/** =rL%P~0wq
* @param beginIndex W4MU^``
* The beginIndex to set. `<Ry_}V
*/ EJAk'L+nuH
publicvoid setBeginIndex(int beginIndex){ ANIx0*Yl(
this.beginIndex = beginIndex; Ax"]+pb
} @4)NxdOE
Oy(fh%k#
/** <Zb~tYp
* @return eyM<#3\\S
* Returns the currentPage. /x2-$a:<
*/ =&%}p[
3g
publicint getCurrentPage(){ Nuc;Y
return currentPage; \mK;BWg)
} aM U0BS"
Gm`#0)VC
/** D*T*of G
* @param currentPage 2Dc2uU@`r
* The currentPage to set. asEk3
*/ o]R*6$
publicvoid setCurrentPage(int currentPage){ '{>R-}o[3
this.currentPage = currentPage; 7~zd
%
o
} |B{@noGX
fBj-R~;0
/** %P8*Az&]T
* @return XRQz~Py
* Returns the everyPage. H18.)yHX
*/ LyR bD$m
publicint getEveryPage(){ ` x|=vu-
return everyPage; ;?h+8Z/{
} K*!qt(D&
`;~A
/** QsemN7B"<
* @param everyPage *F:)S"3_~e
* The everyPage to set. gT-"=AsxZQ
*/ \iP=V3
publicvoid setEveryPage(int everyPage){ NIo!WOi
this.everyPage = everyPage; 0<3->uK
} }xa~U,#5
L'?7~Cdls
/** n0a|GZyO]
* @return !"d"3coQ?
* Returns the hasNextPage. SH1S_EQ<
*/ MlKSjKl" !
publicboolean getHasNextPage(){ ^RI&`5g
return hasNextPage; #ETy#jKL
} E4QLXx6Wa&
,K WIuCU;
/** 7oy}<9
* @param hasNextPage 7:C_{\(
* The hasNextPage to set. 6 l,8ev
*/ -I0J-~#
publicvoid setHasNextPage(boolean hasNextPage){ JGHQzC
this.hasNextPage = hasNextPage; S+ 3lX7
} u7/]Go44
:pH3M[7
/** ]t"X~
* @return %lK/2-
* Returns the hasPrePage. f1$'av
*/ {j8M78 }3
publicboolean getHasPrePage(){ [4 v1
N
return hasPrePage; yM2}JsC
} w}qLI4
_LSp \{Z
/** 1w!O&kn
* @param hasPrePage jct|}U
* The hasPrePage to set. Ur9L8EdC
*/ 8=MNzcA }
publicvoid setHasPrePage(boolean hasPrePage){ PjG^L
FX
this.hasPrePage = hasPrePage; H~NK:qRzK
} 11iV{ h
Y*QoD9<T?;
/** wg UgNwd1
* @return Returns the totalPage. kNd(KQ<.17
* ^wIg|Gc
*/ 64UrD{$o
publicint getTotalPage(){ oTN:Q"oK7?
return totalPage; z&c|2L-u6
} |)65y
*x-@}WY$U
/** /O}lSXo6E
* @param totalPage : i{tqY%
* The totalPage to set. <MyT ;
*/ B,fVNpqo
publicvoid setTotalPage(int totalPage){ 5Q/jI$^h0Z
this.totalPage = totalPage; GIvl|
} KvH t`
-pHUC't
} _iF*BnmN
.% 79(r^
w9w=2 *
Sq SiuO.D
` 7P%muY.
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 9e*o$)j_
m-2!r*(zt
个PageUtil,负责对Page对象进行构造: nX_w F`n"
java代码: 8ZF!}kb0F
dczq,evp
34,'smH i%
/*Created on 2005-4-14*/ K!,9qH
package org.flyware.util.page; Yosfk\D
TWM^5
L :U
import org.apache.commons.logging.Log; W#@6e')d
import org.apache.commons.logging.LogFactory; j#jwK(:]
/K(l[M
/** BJgHel+N
* @author Joa +bGO"*
* jf.WmiDC
*/ $|tk?Sps
publicclass PageUtil { rI OKCL?
2f0mr?l)N
privatestaticfinal Log logger = LogFactory.getLog . {vMn0c
A*~BkvPr
(PageUtil.class); j+PLtE
PA*1]i#2M=
/** T/PmT:Qg`
* Use the origin page to create a new page |'``pq/}_
* @param page OFxCV`>ce
* @param totalRecords !>#gm7
* @return ceuEsQ}
*/ ..R JHa6B
publicstatic Page createPage(Page page, int q`3HHq
A%cJ5dF8~
totalRecords){ UX'q64F!
return createPage(page.getEveryPage(), ?_B'#,tI
Q@!XVQx4
page.getCurrentPage(), totalRecords); dT{GB!jz
} 1k]L ,CX
~d3|zlh
/** }}Zg/(
* the basic page utils not including exception vq+4so
)/S
2Ab`i!#
handler z(u,$vZ_
* @param everyPage o:B?hr'\
* @param currentPage &]tm'N25
* @param totalRecords 3+\Zom4
* @return page Z*b$&nM
*/ $Xh5N3
publicstatic Page createPage(int everyPage, int 0 ;].q*|#
<MKXFV
currentPage, int totalRecords){ !>N+a3
everyPage = getEveryPage(everyPage); HV'M31m~q
currentPage = getCurrentPage(currentPage); g~2=he\C
int beginIndex = getBeginIndex(everyPage, ma xpR>7`j
J/QqwoR
currentPage); 2tg 07
int totalPage = getTotalPage(everyPage, QnJLTBv
kRr/x-"
totalRecords); !ALq?u
boolean hasNextPage = hasNextPage(currentPage, O6,2M[a
_kc}:
totalPage); &7,::$cu
boolean hasPrePage = hasPrePage(currentPage); yFn~rv|&G
ILx4[m7
returnnew Page(hasPrePage, hasNextPage, )%b 5uZ
everyPage, totalPage, Vry*=X&Q
currentPage, [&IcIZ
(+6N)9rj`/
beginIndex); #Cx#U"~G`
} Z^BZH/I?
+^jm_+
privatestaticint getEveryPage(int everyPage){ J 7sH]
return everyPage == 0 ? 10 : everyPage; e _(';Lk
} liqVfB%
PI@?I&Bo
privatestaticint getCurrentPage(int currentPage){ A<^X P-Nrp
return currentPage == 0 ? 1 : currentPage; Yhz Dw8f
} cE>m/^SKr
d+vAm3.Dg
privatestaticint getBeginIndex(int everyPage, int xSm~V3bc
&JYkh >
currentPage){ )w5!'W4Z8
return(currentPage - 1) * everyPage; &'`ki0Xh;
} &^w"
m?gGFxo
privatestaticint getTotalPage(int everyPage, int YS@TQ?
*Z\AO'h=Z
totalRecords){ R!
n7g8I%
int totalPage = 0; 89j:YfA=v
Q3Z?Z;2aR
if(totalRecords % everyPage == 0) N]14~r=
totalPage = totalRecords / everyPage; ,c0t#KgQ.
else f~,Ml*Zp
totalPage = totalRecords / everyPage + 1 ; ?D,j!Hy
c[V.j+Iy#^
return totalPage; ]rSg,Q>E
} YNl".c
(.i wD&
privatestaticboolean hasPrePage(int currentPage){ sIbPMu`&U
return currentPage == 1 ? false : true; K}MlC}oIt
} |3~]XN-
7z$bCO L=S
privatestaticboolean hasNextPage(int currentPage, L0I|V[
<CJy3<$u
int totalPage){ 86 9sS
return currentPage == totalPage || totalPage == >6[d&SM6
$-|$4lrS
0 ? false : true; {2QP6X sJ
} [$uKI,l
k7{|\w%
c<lEFk!g
} _mk@1ft
vC^{,?@
a\~118 !
H+5+;`;
Q1{9>NI
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。 FA\U4l-
_>aP5g?Ep
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 ~{);Ab.9+
-E3cS
做法如下: s|:1z"q
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 uL@%M8n
I}f7|hYX
的信息,和一个结果集List: f& \Bs8la
java代码: $pKegK;'z
xX9snSGz
dz>Jl},`k
/*Created on 2005-6-13*/ X 5X D1[
package com.adt.bo;
H:9G/Nev
S{v]B_N[M
import java.util.List; RnU7|p{
FA;-D5=
import org.flyware.util.page.Page; T$AVMVq
A0RSNAM
/** FzP1b_i
* @author Joa @/ nGc9h
*/ : 2$*'{mM
publicclass Result { 9[W >`JKo
e ky1}
private Page page; $TS97'$
[Y?Y@x"MZ
private List content; QSn18V>{
x]`@%8Sm
/** 9:GP~oI j
* The default constructor wr=KAsH<
*/ wf1p/bpf
public Result(){
>@ xe-0z
super(); ~)`\j
} @$ju Qm
].5q,A]
/** *9w-eK1{
* The constructor using fields r{84Y!k~*
* q_ryW$/_
* @param page $uJc/
* @param content $duT'G, -
*/ .Pte}pM"v
public Result(Page page, List content){ 6w(r}yO]
this.page = page; En#Q
p3
this.content = content; _d!o,=}
} $-~"G,;F
,nCvA%B!
/** CWRB/WH:
* @return Returns the content. h^qZi@L
*/ F
u^j- Io
publicList getContent(){ b62B|0i
return content; Ctn?O~u
} &l!T2PX!
olA+B
/** C^;8M'8z0
* @return Returns the page. L;y BZLM
*/ 7jQVm{{.
public Page getPage(){ .pdcwd9
return page; #$W0%7
} l
9g
'RF`XX
/** @V:Y%#%
* @param content z}.6yHS
* The content to set. @iXBy:@
*/ a
j$& 9][
public void setContent(List content){ Q-F$Ryj^
this.content = content; *h=>*t?I2
} q86}'dFw{
z$}9f*W}B
/** zK1]o-wSAT
* @param page I1l^0@J
* The page to set. H?M:<q0|G
*/ HwZl"!;Mry
publicvoid setPage(Page page){ HC1<zW[
this.page = page; nCp_RJu
} e57R6g)4
} <|?)^;R5!
aaw[ia_E L
Ovj^
7r:<s
S
w%6-
Jc}6kFgO6
2. 编写业务逻辑接口,并实现它(UserManager, @1gURx&2_
\>}#[?y
UserManagerImpl) zS|4@t\__
java代码: IbL'Z
N-&ZaK
]jn1T^D'
/*Created on 2005-7-15*/ <6Y;VH^_
package com.adt.service; njZ vi}m~
TU2oQ1
import net.sf.hibernate.HibernateException; _KkaseR
z07&P;W!{
import org.flyware.util.page.Page; =3A4.nW
c2,g%(
import com.adt.bo.Result; E8"&gblg
5#N<~
/** +>;Ux1'@
* @author Joa @>.aQE
*/ !L
q'o?
publicinterface UserManager { "\`Fu
c}|.U
public Result listUser(Page page)throws DTM(SN8R+n
Lk@+iHf
HibernateException; frW\!r{LT
:A!EjIL`#
} 83
R_8
~<O.Gu&"R
m.`I}
y6-P6T
K5T1dBl,0
java代码: sJ^Ff
-64;P9:A>
'[%Pdd]!
E
/*Created on 2005-7-15*/ $BgaLJs/O
package com.adt.service.impl; j6~`C
?(
#a~BigZ[G
import java.util.List; }cGILH%
z;2& d<h
import net.sf.hibernate.HibernateException; ';8 ,RTe
5S!j$_(
import org.flyware.util.page.Page; :p@jslD
import org.flyware.util.page.PageUtil; #>\SK
RU'a8j+W
import com.adt.bo.Result; e!L5v?
import com.adt.dao.UserDAO; #3LZX!
import com.adt.exception.ObjectNotFoundException; +l/kH9m
import com.adt.service.UserManager; LVm']_K(f
NIQ}+xpC
/** ZsXw]Wa
* @author Joa ("j;VqYUL
*/ 5lP8#O?=
publicclass UserManagerImpl implements UserManager { GHn0(o &K
1!;~Y#
private UserDAO userDAO; ((#BU=0iK
Qbjm,>H/^
/** 1y6<gptx
* @param userDAO The userDAO to set. \b"|p%CL8
*/ hEZo{0:b"
publicvoid setUserDAO(UserDAO userDAO){ 9I
[:#,zdf
this.userDAO = userDAO; 2Q]W
} `$FX%p
eFS$ ;3FP1
/* (non-Javadoc) @M-Q|
* @see com.adt.service.UserManager#listUser K0C"s'q
k}E_1_S(
(org.flyware.util.page.Page) \o2l;1~
*/ I+.U.e^gx
public Result listUser(Page page)throws LEtGrA/%@b
4gev^/^^
HibernateException, ObjectNotFoundException {
^[}W} j>
int totalRecords = userDAO.getUserCount(); .>[l@x"
if(totalRecords == 0) Cg~1<J?2
throw new ObjectNotFoundException oq,nfUA
ni2 [K`
("userNotExist"); I0Allw[
page = PageUtil.createPage(page, totalRecords); fJ5mKN
List users = userDAO.getUserByPage(page); y4|<+9<7
returnnew Result(page, users); ^'tT_
gT
} >@cBDS<6R
8%YyxoCH
} M=ag\1S&ZF
fK]%*i_"
CMbID1M3
|.yS~XFJS
4I2:"CK06
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 G4'Ee5(o
YIZu{
询,接下来编写UserDAO的代码: 'm|T"Ym~
3. UserDAO 和 UserDAOImpl:
E^5
java代码: ;8K>]T)
'q~<ZO
40`Qsv0#
/*Created on 2005-7-15*/ a JjUy%
package com.adt.dao; Akc
|E!V
LH+Bu%s
import java.util.List; RyukQY~<W
\4j_K*V
import org.flyware.util.page.Page; 1i.3P$F
}|) N5bGQe
import net.sf.hibernate.HibernateException; 4ME$Z>eN
<*^|Aj|#
/** kb"Fw:0
* @author Joa q27q/q8
*/ h@1/
publicinterface UserDAO extends BaseDAO { =L1%gQJJ&
)!E:
publicList getUserByName(String name)throws R<Mp$K^b
{:_*P
TVk
HibernateException; =?+w5oI0
T95FoA
publicint getUserCount()throws HibernateException; _7';1 D
lqh:c
publicList getUserByPage(Page page)throws B=^M& {
n{~&^Nby*I
HibernateException; g@M5_I(W
<3N\OV2
} j x< <h_j
rwW"B
%`$:/3P$U
#?D[WTV
>d"\
java代码: i?@7>Ca
vRW;{,d
QQ{*j7i)
/*Created on 2005-7-15*/ {g1R?W\LZ
package com.adt.dao.impl; :(/1,]bF
EXH,+3fQp
import java.util.List; AB+lM;_>
>$CNR*}@
import org.flyware.util.page.Page; ~l] w=[
z
[N%InsA9k
import net.sf.hibernate.HibernateException; Ez-AQ'
import net.sf.hibernate.Query; ;g+fY6
'-I\G6w9
import com.adt.dao.UserDAO; $RF.LVc
^qBm%R(
/** @cxM#N8e
* @author Joa O0BDUpH
*/ -Q
Mwtr#q}
public class UserDAOImpl extends BaseDAOHibernateImpl 4L`,G:J,;
:2NV;7Wke6
implements UserDAO { [)8O\/:
5?Q5cD2]\6
/* (non-Javadoc) 5&L*'kV@
* @see com.adt.dao.UserDAO#getUserByName 'x?|tKzd
8dt=@pwx&
(java.lang.String) mRyf+O[
*/ +jq@!P"}d
publicList getUserByName(String name)throws jVGAgR=[G
%yKcp5_
HibernateException { vmOye/?k
String querySentence = "FROM user in class AA ~7"2e
47*2QL^zj
com.adt.po.User WHERE user.name=:name"; E#tfCM6
Query query = getSession().createQuery vZS/?pU~~
^b$G.h{o!E
(querySentence); Rc D5X{qS#
query.setParameter("name", name); fwzyCbks
return query.list(); Bonj K#
} =F/ R*5:T
i
Pl/I
/* (non-Javadoc) zp'hA
* @see com.adt.dao.UserDAO#getUserCount() ?;5/"/i
*/ Nknd8 >Hy+
publicint getUserCount()throws HibernateException { ;O,&MR{;|n
int count = 0; =)i^E9
String querySentence = "SELECT count(*) FROM Y Kp@n8A
L.K| ]]u
user in class com.adt.po.User"; mKV31wvK}
Query query = getSession().createQuery pK_zq
rij%l+%@#
(querySentence); ~mah.8G
count = ((Integer)query.iterate().next 'aD"v>
Wie0r@5E
()).intValue(); F8tMZ,:
return count; .ty2! .
} gwg~4:W
).u>%4=6
/* (non-Javadoc) ]0%{IgB
* @see com.adt.dao.UserDAO#getUserByPage &A/b9GW^-
7OXRR)]V
(org.flyware.util.page.Page) =*+f2
*/ Iw#[K
publicList getUserByPage(Page page)throws <bhJ >
>nK (
HibernateException { RASk=B
String querySentence = "FROM user in class MOB'rPIUI
}y+a)2
com.adt.po.User"; OzRo
Query query = getSession().createQuery w+!V,lU"^
:l
Z\=2D
(querySentence); 8/,s8u
query.setFirstResult(page.getBeginIndex()) }
MP_
.setMaxResults(page.getEveryPage()); 3y:),;|5
return query.list(); ab)ckRC
} r,vSDHb`j
I7'v;*
} KlBT9"6"
l#+@!2z
|r+hj<K
i \lr
KA
7VkjnG^!:
至此,一个完整的分页程序完成。前台的只需要调用 6BQq|:U
v6x jLP;O
userManager.listUser(page)即可得到一个Page对象和结果集对象 ~ \u>jel
m#6p=E
的综合体,而传入的参数page对象则可以由前台传入,如果用 ~W B-WI\
#q&Nd2y
webwork,甚至可以直接在配置文件中指定。 k#mL4$]V5N
56NDU>j$
下面给出一个webwork调用示例: 7s:cg
java代码: 2AxKB+c1`
a~-k} G5
%^"i\-*|S
/*Created on 2005-6-17*/ 4m~p(r
package com.adt.action.user; kqC7^x
S|yDGT1
import java.util.List; dOgc%(kz
mwz!7Q
import org.apache.commons.logging.Log; H6$pA^
import org.apache.commons.logging.LogFactory; yB;K|MXy?
import org.flyware.util.page.Page; =3;!
5P
`VglE?M
import com.adt.bo.Result; ?$/W3Xn0%
import com.adt.service.UserService; {K/xI
import com.opensymphony.xwork.Action; i5*/ZA_
!g~u'r'1
/** #Wv8+&n
* @author Joa uBM%E OE
*/ 4QNwu7TeR
publicclass ListUser implementsAction{ 4!'4 l=jO
kO/;lrwC
privatestaticfinal Log logger = LogFactory.getLog AVc|(~V
/" &Jf}r
(ListUser.class); \C1`F[d_
V`feUFw3
private UserService userService; a'my0m
Q b5vyV `
private Page page; $KGRpI
#_Lgo
privateList users; "(\]-%:7
x.(Sv]+[
/* zj1_#=]
* (non-Javadoc) pM!cF
* <2I<Z'B,e
* @see com.opensymphony.xwork.Action#execute() Et)j6xz/F
*/ 8..g\ZT
publicString execute()throwsException{ }.<]A
Result result = userService.listUser(page); s8r[U, }(
page = result.getPage(); }\ya6Gi8
users = result.getContent(); N&