Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 <%mRSv
;mi%F3
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 ,<X9 Y2B
|6y
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 Rf% a'b
"$vRMpW:
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 0<*<$U
Vi|#@tC'
。 {Y1Ck5
tpx2IE
分页支持类: i"=\d
b7ZSPXV
java代码: NwfVL4Xg
sa8Vvzvo.
PQE=D0
package com.javaeye.common.util; DVeE1Q
A]3k4DLYS
import java.util.List; \GU<43J2uo
b\5F ]r
publicclass PaginationSupport { !bP@n
{K!)Ss
publicfinalstaticint PAGESIZE = 30; o{[qZc_%
Wa~=bH
privateint pageSize = PAGESIZE; z0Z%m@
!dT4
privateList items; 5~S5F3
.jK4?}]
privateint totalCount; tT._VK]o&R
Ew$C
;&9
privateint[] indexes = newint[0]; *yGGBqd
5`_SN74o
privateint startIndex = 0; 6wg^FD_Q
f?)-}\[IR{
public PaginationSupport(List items, int @E8+C8'
5Ynd c)Z
totalCount){ UGatWj
setPageSize(PAGESIZE); $Ygue5{c
setTotalCount(totalCount); *OQ2ucC8j
setItems(items); - !
S_ryL
setStartIndex(0); f)<6
} x|29L7i
CU~PT.
public PaginationSupport(List items, int MUwMb!Z.s
onV>.7sG
totalCount, int startIndex){ Fs^Mw
go
setPageSize(PAGESIZE); Y|/ 8up
setTotalCount(totalCount); VS|2|n1<6
setItems(items); YHl;flv
setStartIndex(startIndex); bs1Rvx1:J%
} ;9'OOz|+1
. 'yCw#f
public PaginationSupport(List items, int *n"{J(Jt`
o<!?7g{
totalCount, int pageSize, int startIndex){ m)D|l1AtF
setPageSize(pageSize); |+"(L#wk
setTotalCount(totalCount); t3^&;&[
setItems(items); U`s{Jm
setStartIndex(startIndex); HLi%%"'
} XB5DPx
\.}c9*)
publicList getItems(){ 9MqGIOQ${j
return items; NyuQMU
} ]}X
Vf1^4t
publicvoid setItems(List items){ Dum9lj
this.items = items; k==h|\|
} -D~%|).'
|vzl. ^"-
publicint getPageSize(){ h@wgd~X9
return pageSize; lk80#( :Z
} e@YK@?^#N
r,2g^K)6
publicvoid setPageSize(int pageSize){ <=C?e<Y
this.pageSize = pageSize; @=f\<"$vt
} 3irl
(;v
'/%H3A#L
publicint getTotalCount(){ H" 7u7l
return totalCount; k~z Iy;AZ
} g#E-pdY
pI<f) r
publicvoid setTotalCount(int totalCount){ l}M!8:UzU
if(totalCount > 0){ o[D9I
hs
this.totalCount = totalCount; Srd4))2/0
int count = totalCount / is@?VklnB
5Jnlz@P9
pageSize; E&:,oG2M
if(totalCount % pageSize > 0) <ZR9GlIr
count++; \z}
Ic%Tp
indexes = newint[count]; oe~b}:
for(int i = 0; i < count; i++){ q-d:TMkc
indexes = pageSize * Y`wSv NU
7E!5G2XX~~
i; sW8dPw
O
} Yu2Bkq+
}else{ "-V"=t'
this.totalCount = 0; ?!/kZM_ts
} %vi83%$'4
} BING{ew
El"Q'(:/U
publicint[] getIndexes(){ LBP`hK:>W~
return indexes; ?=pT7M
} Yc*;/T}
ENY+^7
publicvoid setIndexes(int[] indexes){ |]*/R^1>2
this.indexes = indexes; ;i+#fQO7Q
} 8DaL,bi*.
%ULr8)R;
publicint getStartIndex(){ o2\8OxcA
return startIndex; R@rBEW&
} d m%8K6|
;i:d+!3XwC
publicvoid setStartIndex(int startIndex){ QkC(uS
if(totalCount <= 0) q'MZ R'<@
this.startIndex = 0; ;gr9/Vl
elseif(startIndex >= totalCount) IIx#2r
this.startIndex = indexes uY'HT|@:{
^K@C"j?M/
[indexes.length - 1]; ` sU/& P
elseif(startIndex < 0) H}
g{Cr"Ex
this.startIndex = 0; )w%!{hn
else{ R*r#E{!V;
this.startIndex = indexes S|+o-[e8O
8}| (0mC
[startIndex / pageSize]; |P}y,pNQ
} u,4eCxYE$
} UW
EV^ &"x
JqiP>4Uwm^
publicint getNextIndex(){ }JAG7L&{
int nextIndex = getStartIndex() + =odFmF
)53y
AyP
pageSize; du^J2m{f
if(nextIndex >= totalCount) *CHX
return getStartIndex(); *4Y Vv
else (Ep\Z 6*
return nextIndex; !%0 *z
} |ZBI *
#Mw8^FST
publicint getPreviousIndex(){ #>+ HlT
int previousIndex = getStartIndex() - Y:a]00&)#Y
~&bq0(
pageSize; uGlUc<B\*
if(previousIndex < 0) h'F=YF$o
return0; P";'jVcR
else =rX>.P%Q 5
return previousIndex; n.0fVV-A
} ZJs$STJ*
n?Nt6U
} 92KRb;c
}`~+]9<
|
%Vh`HT
}pu27F)&
抽象业务类 LFtt gY
java代码: %bfQ$a:
<UQbt N-B\
'."ed%=MC
/** 3$9W%3
* Created on 2005-7-12 w+CA1q<
*/ n7-6-
#
package com.javaeye.common.business; <e</m)j
3:i@II
import java.io.Serializable; TWFr
4-
import java.util.List; CizX<Cr}
3/n5#&c\4
import org.hibernate.Criteria; k\GcHI-
import org.hibernate.HibernateException; RrQJ/ts7}
import org.hibernate.Session; )P|),S,;Z
import org.hibernate.criterion.DetachedCriteria; "LTad`]<Ro
import org.hibernate.criterion.Projections; <W $mj04@
import Z?m3~L9L2
`+Q%oj#FF
org.springframework.orm.hibernate3.HibernateCallback; j8lb~0JD
import 9;-p'C
?<'}r7D
org.springframework.orm.hibernate3.support.HibernateDaoS #4 pB@_
TbW38\>.R
upport; jtc]>]6i
NHZz _a=
import com.javaeye.common.util.PaginationSupport; s,&Z=zt0R
JnM["Q=`
public abstract class AbstractManager extends '(|ofJe!
_zi|
HibernateDaoSupport { WEi2=3dV
SNI)9k(T{
privateboolean cacheQueries = false; Hja3a{LH
nc|p )
privateString queryCacheRegion; 5"O.,H}
X_\otVh(D
publicvoid setCacheQueries(boolean kL"2=7m;
'$%l7
cacheQueries){ 4@#
`t5H
this.cacheQueries = cacheQueries; ._{H~R|
} @r/nF5
wcY?rE9
publicvoid setQueryCacheRegion(String #'9HU2
}Ud*TOo `
queryCacheRegion){ _>X+ZlpU:
this.queryCacheRegion = 0^K">
eV?2LtT#5
queryCacheRegion; b2&0Hx
} vnZC,J `
RdRp.pb8
publicvoid save(finalObject entity){ [:SWi1cK2
getHibernateTemplate().save(entity); <l E<f+
} ]|PiF+
_^%,x
publicvoid persist(finalObject entity){ (M.&^w;`,
getHibernateTemplate().save(entity); N64dO[op
} Cd}<a?m,
VQ9/Gxdeo
publicvoid update(finalObject entity){ )
ahA[
getHibernateTemplate().update(entity); nk's_a*Z
} sN01rtB(UT
*mvlb
(' &
publicvoid delete(finalObject entity){ H*'IK'O
getHibernateTemplate().delete(entity); l?n\i]'
} JO6)-U$7UG
|imM#wF
publicObject load(finalClass entity, pJ'"j 6Q
U>}w2bZ*
finalSerializable id){ ,M
^<CJ
return getHibernateTemplate().load @O^6&\s>
dE{dZ#Jfi
(entity, id); ]Ntmy;Q
} K} X&AJ5A
}l} Bo.C
publicObject get(finalClass entity, x\G'kEd
OU
$#5
finalSerializable id){ w-L=LWL\
return getHibernateTemplate().get PmEsN&YP]
3eAX.z`D
(entity, id); }Sh?S]]`
} mLLDE;7|}
]:k/Y$O2
publicList findAll(finalClass entity){ C7ScS"~
return getHibernateTemplate().find("from 84zSK)=Y
uo%)1NS!
" + entity.getName()); rlSeu5X6
} ~
=2PU$u
YHygo#4=8
publicList findByNamedQuery(finalString Pw`8Wj
yZ U6xY
namedQuery){ y'nK>)WG4
return getHibernateTemplate B7E:{9l~s{
u[=r,^YQ
().findByNamedQuery(namedQuery); 0gP}zM73
} X[BIA+6
0)e\`Bv
publicList findByNamedQuery(finalString query, A&Usddcp
tGE$z]1c@
finalObject parameter){ 9`X\6s
return getHibernateTemplate hT&Y#fh
>rmqBDKaQ
().findByNamedQuery(query, parameter); 2*l/3VW
} bUdLs.:
Q1I6$8:7
publicList findByNamedQuery(finalString query, ]dmrkZz:
&d?CCb$|0Y
finalObject[] parameters){ }?_?V&K|
return getHibernateTemplate 4-y:/8
By",rD- r
().findByNamedQuery(query, parameters); RmeD$>7
} SBk4_J/_
u$Jz~:=,
publicList find(finalString query){ [
=9T*Sp
return getHibernateTemplate().find #:U%mHT(_
)e=D(qd
(query); ;rGwc$?|
} cj|80$cSA
Zbt.t]N
publicList find(finalString query, finalObject '9Xu
p
Vl=l?A8
parameter){ s.QwSbw-g
return getHibernateTemplate().find d_E/8R_$L
rCbDu&k]
(query, parameter); SaAFz&WRl
} `*cxH..
3-qr)h
public PaginationSupport findPageByCriteria b)5uf'?-
Ru!iR#s)!
(final DetachedCriteria detachedCriteria){ H0gbSd+
return findPageByCriteria 7p16Hv7y~
IT7wT+
(detachedCriteria, PaginationSupport.PAGESIZE, 0); J~zUp(>K
} */^q{PsN
;dtA4:IRZ4
public PaginationSupport findPageByCriteria /}fHt^2H
{{D)YldtA
(final DetachedCriteria detachedCriteria, finalint *-=(Q`3
%i9E @EV
startIndex){ GxI!{oi2
return findPageByCriteria U}e!Wjrc
S.94edQ
(detachedCriteria, PaginationSupport.PAGESIZE, K6/Q}W
lH x^D;m6
startIndex); RYQR(v
} SpLzm A
rv^@, 8vq
public PaginationSupport findPageByCriteria n&;85IF1
TA`1U;c{n
(final DetachedCriteria detachedCriteria, finalint =_ ./~
(ybI\UI
pageSize, i$:*Pb3mV
finalint startIndex){ ;!mzyb*
return(PaginationSupport) L:pYn_
d *|Y
o
getHibernateTemplate().execute(new HibernateCallback(){ L~rBAIdD
publicObject doInHibernate vrhT<+q
JPc+rfF
(Session session)throws HibernateException { 8:c-k|CX
Criteria criteria = ]}-7_n#cC
rq/yD,I,
detachedCriteria.getExecutableCriteria(session); r6MMCJ|G
int totalCount = ;4^Rx
kHghPn?8]
((Integer) criteria.setProjection(Projections.rowCount 2G67NC?+
RXpw!
()).uniqueResult()).intValue(); rb2S7k0{
criteria.setProjection vv3*
j&I
5T_n %vz
(null); a LroD$#
List items = mPtZO*Fc
4$iz4U:P
criteria.setFirstResult(startIndex).setMaxResults q77;ZPfs8
/ivJsPH
(pageSize).list(); Pmr5S4Ka
PaginationSupport ps = B:;pvW]
8>2.UrC
new PaginationSupport(items, totalCount, pageSize, j9x<Y]
fcRxp{*zO
startIndex); _"Dv
uR
return ps; 7a=gH2]&
} L%*!`TN
}, true); hYT0l$Ng
} szZr4y<8|1
L
O_k@3
public List findAllByCriteria(final SO|NaqWa
[fya)}
DetachedCriteria detachedCriteria){ hLd^ agX
return(List) getHibernateTemplate TluW-S
zU kgG61
().execute(new HibernateCallback(){ dUeN*Nq&(,
publicObject doInHibernate )BZ.Sv
KQaxvU)L
(Session session)throws HibernateException { g|DF[
Criteria criteria = q1$N>;&
p*R;hU
detachedCriteria.getExecutableCriteria(session); Cx(>RXVoJ,
return criteria.list(); Fh?gNSWq6
} ??-[eB.
}, true); 0U(@=7V
} {3>$[bT
1b `1{%
public int getCountByCriteria(final ~ drS} V
zH?!
DetachedCriteria detachedCriteria){ jH5
k
Integer count = (Integer) l[mWf
4C6YO
getHibernateTemplate().execute(new HibernateCallback(){ 6"LcJ%o
publicObject doInHibernate U2tV4_ e
&Cq`Y !y
(Session session)throws HibernateException { 75cW_t,g
Criteria criteria = {NmWQyEv
T6y\|
detachedCriteria.getExecutableCriteria(session); 'Vzp2
return EA@.,7F
fIx+ILs
criteria.setProjection(Projections.rowCount 4x=v?g&
zsEc(
()).uniqueResult(); $-OA'QwB]
} BM%e0n7
}, true); AP n| \
return count.intValue(); m)ky*"(
} :[p}
} XV7Ex\D*
)al]*[lY
VZp5)-!\
!_]Y~[
O@T9x$
2@n{yYwy
用户在web层构造查询条件detachedCriteria,和可选的 [`#CXq'
@wGPqg
startIndex,调用业务bean的相应findByCriteria方法,返回一个 SB;&GHq"n
G, }Yl
PaginationSupport的实例ps。 }/0X'o
\#2Z)Kz
ps.getItems()得到已分页好的结果集 j"t(0m
ps.getIndexes()得到分页索引的数组 WrnrFz
ps.getTotalCount()得到总结果数 ^H p; .f.
ps.getStartIndex()当前分页索引 @N>\|!1CC
ps.getNextIndex()下一页索引 4qb/daE:Z
ps.getPreviousIndex()上一页索引 SXSgld2uS
I13y6= d
bQzZy5,
xeg/A}yE
)nC]5MXU
@+&LYy72
x77*c._3v
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 WA<v9#m
\#8D>i?m
,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 AVsDt2A
euK5pA>L
一下代码重构了。 mxvp3t \
b<tNk]7
我把原本我的做法也提供出来供大家讨论吧: >2Y=*K,:
]{;gw<T
首先,为了实现分页查询,我封装了一个Page类: $g^@AdE%
java代码: ]}>2D,;
6B8VfQ9[
f$o_e90mu
/*Created on 2005-4-14*/ vz@A;t
package org.flyware.util.page; 3<e=g)F
Yj<a"
Gr4[
/** 7m47rJyW4
* @author Joa bt@<
ut\
* vOH4#
*/ XnH05LQ
publicclass Page { 3p$?,0ELH
*[Imn\hu
/** imply if the page has previous page */ `Y0%cXi3
privateboolean hasPrePage; R)?*N@.s
0gu_yg! R
/** imply if the page has next page */ [CTnXb
privateboolean hasNextPage; /m!BY}4W
` _6C{<O
/** the number of every page */ H-!,yte
privateint everyPage; 8v6(qBK
6lZ3tdyNo
/** the total page number */ v1#otrf
privateint totalPage; (fhb0i-
4V"E8rUL(
/** the number of current page */ zF@/K`
privateint currentPage; h7*J9[$
A\*>TN>s
/** the begin index of the records by the current Ky`qskvu
=?5]()'*n
query */ b.OsiT;_j
privateint beginIndex; h<h%*av|
(Nq=H)cm8
p
.%]Q*8
/** The default constructor */ #]-SJWf3
public Page(){ ;'gWu
xW+6qtG`
} p0]=QH
mwO6g~@`
/** construct the page by everyPage ^23~ZHu
* @param everyPage m%0p\Y-/
* */ I<DL=V
public Page(int everyPage){ 7:e{;iG
this.everyPage = everyPage; b8H{8{wi|
} 5G}?fSQ>
Q1lyj7c#x
/** The whole constructor */ V~qNyOtA]
public Page(boolean hasPrePage, boolean hasNextPage, ~\r*
HGl|-nW>
TbMW|0 #w
int everyPage, int totalPage, \a<wKTkn
int currentPage, int beginIndex){ hy9\57_#
this.hasPrePage = hasPrePage; 1l9G[o
*
this.hasNextPage = hasNextPage; Oz.HH
this.everyPage = everyPage; EX*HiZU>
this.totalPage = totalPage; 4a&RYx
this.currentPage = currentPage; 2bz2KB5>
this.beginIndex = beginIndex; //B&k`u
} ;2G*wR
&.3"Uo\#
/** &*o=I|pQ
* @return }ZYd4h|g\z
* Returns the beginIndex. 3s*mbk[J
*/ `4r 3l S
publicint getBeginIndex(){ _9ao?:
return beginIndex; +tB=OwU%0
} ]IaMp788
~"gA,e-)
/** rV.}PtcFY
* @param beginIndex ` #0:gEo
* The beginIndex to set. ;J'LS
*/ 1> ?M>vK
publicvoid setBeginIndex(int beginIndex){ n>z9K')
this.beginIndex = beginIndex; xl{=Y< ;
} 5#6|j?_a
:x3QRF
/** 'I|v[G$l
* @return LPXi+zj
* Returns the currentPage. 39c2pV[
*/ g_E$=j92v
publicint getCurrentPage(){ ?PLPf>e
return currentPage; . P viA
} I]|Pq
oE@a'*.\
/** ;T\%|O=Ke
* @param currentPage hXw]K"
* The currentPage to set. AhN4mc@
*/ _1X!EH"
publicvoid setCurrentPage(int currentPage){ BX/8O<s0
this.currentPage = currentPage; 7jrt7[{
} +D6YR$_<
';k5?^T
/** W<{h,j8
* @return |o"?gB}Dh
* Returns the everyPage. ^^u5*n+5
*/ gE'sOT9v
publicint getEveryPage(){ ,O5NLg-
return everyPage; ~i= _J3'
} I@\lN&HC
+ /G2fhE
/** {L971W_L
* @param everyPage U)TUOwF
* The everyPage to set. 3ZuZ/=
*/ !vi>U|rh
publicvoid setEveryPage(int everyPage){ ]|pe>:gf'
this.everyPage = everyPage; >IafUy
} te`$%NRl
W ~<^L\Lu
/** u~N?NW Q
* @return iO$8:mxm0?
* Returns the hasNextPage. Cl.x'v
*/ !<|4C6X:4
publicboolean getHasNextPage(){ sfH_5
#w
return hasNextPage; 5&g@3j]
} Oamg]ST
]OhiYU4
/** $QF{iV@6d4
* @param hasNextPage f^ZRT@`O
* The hasNextPage to set. Rr$-tYy6
*/ Oxnp0 s
publicvoid setHasNextPage(boolean hasNextPage){ FgnTGY}
this.hasNextPage = hasNextPage; t^-d/yKt0w
} R+:yVi[F]U
OF>mF~
/** 2>9C-VL2
* @return z|uDy2
* Returns the hasPrePage. .#!lP/.eQP
*/ Y|m+dT6
publicboolean getHasPrePage(){ jwe *(k]z
return hasPrePage; l9~e".
~'
} h8j.(
? V1*cVD6i
/** yu {d! {6
* @param hasPrePage t,Lrfv])
* The hasPrePage to set. >{]%F*p4
*/ G5_=H,Vmd
publicvoid setHasPrePage(boolean hasPrePage){ umfD>" ^I
this.hasPrePage = hasPrePage; ~D+bh~
} # +>oZWVc
ldcqe$7,
/** 68|E9^`l
* @return Returns the totalPage. S\EyCi+
* f%JIp#B
*/ ITQA0PISL
publicint getTotalPage(){ w(Ovr`o?9t
return totalPage; )}R0Y=e
} ~NgA
]! &FKy
/** BZ#(
* @param totalPage Y Uc+0
* The totalPage to set. pad*oPH,
*/ gaxsv[W>^
publicvoid setTotalPage(int totalPage){ \sixI;-2
this.totalPage = totalPage; 2DrM3ZU8
} 9=M$AB
;+_:,_
} YqD=>P[O
^e5=hH-%
|i*37r6]=
u#fM_>ML
/62!cp/F/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 ,KZ~?3$yj
!n!*/[}X
个PageUtil,负责对Page对象进行构造: 8nqG<!,q
java代码: s[*rzoA
#zy:a%
Es`Px_k
/*Created on 2005-4-14*/ DK~xrU'
package org.flyware.util.page; ~_)^X
@;4zrzQi7
import org.apache.commons.logging.Log; G>=*yqo
import org.apache.commons.logging.LogFactory; octL"t8w
2s8a
$3
/** l30EKoul)
* @author Joa Wi<m{.%\E
* @{e}4s?7od
*/ ]q[D>6_
publicclass PageUtil { l'1pw
uZYF(Yu
privatestaticfinal Log logger = LogFactory.getLog S?LQu
gg/-k;@ Rf
(PageUtil.class); jd"@t*ZV
J{<X7uB
/** T<>,lQs(a
* Use the origin page to create a new page E=Bf1/c\
* @param page Oszj$C(jF
* @param totalRecords :,7hWs
* @return ttQGoUkj
*/ {fM'6;ak
publicstatic Page createPage(Page page, int ~=LE0. 3[
W
i.&e
totalRecords){ VGN5<?PrN
return createPage(page.getEveryPage(), B-Hrex]
e>OoyDZ@R
page.getCurrentPage(), totalRecords); UDFDJm$
} Z\rwO>3
4"ZP 'I;
/** YP<ms
* the basic page utils not including exception _61gF[r4!Y
gVuFHHeUz
handler VQ@
* @param everyPage e%M;?0j
* @param currentPage Y|qTyE%
* @param totalRecords {S\{Ii6
* @return page ?z+eWL
*/ {YC@T(
publicstatic Page createPage(int everyPage, int ]/6z;
~3U
Ix}sK"}[n
currentPage, int totalRecords){ e`s
~.ZF
everyPage = getEveryPage(everyPage); 4J?0bZ
currentPage = getCurrentPage(currentPage); G_JA-@i%
int beginIndex = getBeginIndex(everyPage, 372rbY
TX/Xt7#R:
currentPage); ,p a {qne
int totalPage = getTotalPage(everyPage, 'Is kWgc
y^*~B(T{
totalRecords); T!{w~'=F
boolean hasNextPage = hasNextPage(currentPage, .{^5X)
9*wK@yEl
totalPage); 9FR5Jw>t
boolean hasPrePage = hasPrePage(currentPage); N"R]Yp;j
HiFUv>,u
returnnew Page(hasPrePage, hasNextPage, @HC Vmg:
everyPage, totalPage, OT*mO&Z
currentPage, I{2hfKUe`
Om@;J%u/
beginIndex); 5DZ#9m/
} gD?l-RT>
$PPi5f}HD
privatestaticint getEveryPage(int everyPage){ Zi
i
return everyPage == 0 ? 10 : everyPage; 7]bGc
\
} b|DdG/O
(t|Zn@uY
privatestaticint getCurrentPage(int currentPage){ w9imKVry
return currentPage == 0 ? 1 : currentPage; *^4"5X@
} n>XdU%&
<lPG=Xt
privatestaticint getBeginIndex(int everyPage, int JQI: sj
q;CiV
currentPage){ A)!*]o>U
return(currentPage - 1) * everyPage; '<<t]kK[N
} c?-H>u
t{kG<J/l
privatestaticint getTotalPage(int everyPage, int Llo"MO*sr
/6*42[r
totalRecords){ +'a^f5
int totalPage = 0; !pW0qX\1n
d0ksG$
if(totalRecords % everyPage == 0) /~?*=}c^m
totalPage = totalRecords / everyPage; GxxW&y
else %> eiAB_b
totalPage = totalRecords / everyPage + 1 ; 7}>E J
ki!0^t:9
return totalPage; "^-a M
} WT=;: j
~!L}yw
privatestaticboolean hasPrePage(int currentPage){ 4VSU8tK|N]
return currentPage == 1 ? false : true; Sm|6 %3
} VA5xp]
CCx&7f
privatestaticboolean hasNextPage(int currentPage, Hn"RH1Zy
9A=,E&
int totalPage){ 4HlQ&2O%#
return currentPage == totalPage || totalPage == IJ"q~r$
`^&OF uee
0 ? false : true; eauF~md,
} 4[eXe$
cwg"c4V
H{wl% G
} L4HI0Mx
/4Gt{ygSr
jLluj
R/YqyT\SM
5]0<9a
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。 %h@EP[\
&8lZNv8;(p
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 e"<OELA
VPo".BvG6
做法如下: Nf\LN$ &8
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 o+'6`g'8
0l6.<-f{
的信息,和一个结果集List: (<9u-HF#
java代码:
8A#;WG
4hj|cCrO
mzgfFNm^G)
/*Created on 2005-6-13*/ Zy/_
E@C}u
package com.adt.bo; hgq;`_;1,
0=YI@@n)
import java.util.List; qE"OB
fJg+ Ryo
import org.flyware.util.page.Page; H:|uw
9'B `]/L
/** |BXg/gW
* @author Joa Zh~'9 JH
*/ yWSGi#)1
publicclass Result { xqh
<hyKu
private Page page; /{I$ #:M
2,b$7xaf
private List content; !nnC3y{G
>(<f 0
/** $&c*'3
* The default constructor _[BP0\dPW
*/ hZb_P\1X
public Result(){ /n&&Um\
super(); @0''k
} jP.dDYc
8s@3hXD&
/** >t+P(*u
* The constructor using fields nw<uyaU-t
* [a(#1
* @param page xmoxZW:
* @param content :3 mh@[V
*/ +}AI@+
public Result(Page page, List content){ "AqB$^S9t
this.page = page; 8oGRLYU N
this.content = content; 2 %]X+`+O
} AbM'3Mkz
H PVEnVn
/** 2=}FBA,2
* @return Returns the content. x8|J-8A(
*/
Hl=xW/%6y
publicList getContent(){ 2\$oV
return content; yHaGkm
} c71y'hnT
dE3) |%
/** |-H&o]
* @return Returns the page. \;Weizq5
*/ er\|i. Y
public Page getPage(){ L~3Pm%{@A
return page; 0jfuBj5!
} 4+tEFxvX&
4qa.1j(R/
/** U<XG{<2
* @param content "dlVk~
* The content to set. /-s6<e!
*/ |s_GlJV.
public void setContent(List content){ E qiY\/S
this.content = content; #dHa,HUk
} yhJ@(tu.Gd
:4|4 =mkr
/** !)$Zp\Sg
* @param page ~TtiO#,t
* The page to set. +ZV5o&V>
*/ /9X7A;O
publicvoid setPage(Page page){ Hn:Crl y#
this.page = page; 7+*WH|Z@
} D%Z|
} W+*
V)tf
?JUeuNs9
O6Y0XL
j<$2hiI/?&
l,).p
2. 编写业务逻辑接口,并实现它(UserManager, G~m<;
>Q*Wi
UserManagerImpl) F0#
'WfM#
java代码: *zLMpL_
AXB7oV,xt
Ys7]B9/1O
/*Created on 2005-7-15*/ y{Q
{'De
package com.adt.service; I1J-)R+
"N#Y gSr
import net.sf.hibernate.HibernateException; ^zr`;cJ+c
Y/oHu@
_
import org.flyware.util.page.Page; wC*X4 '
i/.6>4tE:
import com.adt.bo.Result; lquLT6]
m {}Lm)M
/** 9BB=YnKE
* @author Joa HOi`$vX}N
*/ P<-@h1p,
publicinterface UserManager { TA\vZGJ('
k:%%/
public Result listUser(Page page)throws q\ %I#1
A%vbhD2;W
HibernateException; {`_i`
+T+#q@
} \. S/|
$;PMkUE
\<K5ZIWV
zm# ?W
iow"n$/
java代码: 4Tc~b3\!Y
)%]J>&/0J
3' 'me
/*Created on 2005-7-15*/ IGgL7^MF
package com.adt.service.impl; ,: ^u-b|
~"bVL[
import java.util.List; *^r}"in
o;*Q}Gr<M
import net.sf.hibernate.HibernateException; fV~~J2IK
_v:SP
L U
import org.flyware.util.page.Page; `@%LzeGz
import org.flyware.util.page.PageUtil; ]@TCk8d$0
]###w;
import com.adt.bo.Result; 4e
import com.adt.dao.UserDAO; y>LBl]
import com.adt.exception.ObjectNotFoundException; @+DX.9
import com.adt.service.UserManager; DfB7*+x{
#Q5o)x
/** tBSW|0
* @author Joa R!1p^~/
*/ {)Xy%QV
publicclass UserManagerImpl implements UserManager { &j6erwaT
62u4-}JzF
private UserDAO userDAO; ?4uL-z](V
)gi9f1n`
/** d5 -qZ{W
* @param userDAO The userDAO to set. <naz+QK'
*/ [B3RfCV{
publicvoid setUserDAO(UserDAO userDAO){ X{VOAcugr
this.userDAO = userDAO; ZC8wA;!z^
} ,u m|1dh
)}vl\7=
/* (non-Javadoc) P
{'b:C
* @see com.adt.service.UserManager#listUser `_h&glMJ,q
[ hsds\
(org.flyware.util.page.Page) 8k79&|
*/ :KO2| v\
public Result listUser(Page page)throws Va8&Z
z%kULTL
HibernateException, ObjectNotFoundException { !9x}
int totalRecords = userDAO.getUserCount(); R-Sym8c
if(totalRecords == 0) -qoH,4w
throw new ObjectNotFoundException
8Y?;x}
q(}bfIf
("userNotExist"); V8(-
page = PageUtil.createPage(page, totalRecords); pot~<d`:K"
List users = userDAO.getUserByPage(page); ce(#2o&`
returnnew Result(page, users); Ca\6vR
} N21smC}
;}t(Wnu.
} %)n=x
ne
Ho%CDz
z
+[P{&\d4}
Zc2PepIg
0YHFvy)
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 Dh*n!7lD`
g&.=2uP
询,接下来编写UserDAO的代码: I@3MO0V^
3. UserDAO 和 UserDAOImpl: &{i{XcqH'
java代码: NVs@S-rpX
G&dKY h\
F}zDfY\-
/*Created on 2005-7-15*/ z)"=:o7
package com.adt.dao; ~XIb\m9H
f!"w5qC^
import java.util.List; E_`=7i
@XVTU
import org.flyware.util.page.Page; Ep}s}Stlr}
uw7zWJ
n
import net.sf.hibernate.HibernateException; ElXFeJ%[G
s @C}P
/** =Sv/IXX\di
* @author Joa y}H!c;
*/ \Cj B1]I
publicinterface UserDAO extends BaseDAO { 7d vnupLh
`x|?&Ytmf9
publicList getUserByName(String name)throws p#Bi>/C6
O@P"MXEG
HibernateException; t^L]/$q
5X+A"X
;C
publicint getUserCount()throws HibernateException; #1[u(<AS
rs.)CMk53
publicList getUserByPage(Page page)throws U6VKMxSJ
BuwY3F\-O
HibernateException; Xeajxcop#
[gB+C84%%
} F\!
`/4
{8aTV}Ha2
*](iS
l^qI,M
_j3f Ar(V
java代码: |{8Pb3#U
626r^c=
rGO8!X 3d
/*Created on 2005-7-15*/ :-'qC8C
package com.adt.dao.impl; ]{iQ21`a-
#*}+J3/
import java.util.List; "}!G!k:
#`IN`m|
import org.flyware.util.page.Page; MJvp6n
Vc2`b3"Br
import net.sf.hibernate.HibernateException; Jb(H %NJ
import net.sf.hibernate.Query; nwWJ7M,A
3u;oQ5<(v
import com.adt.dao.UserDAO; =}*0-\QG
<qSC#[xu
/** OYd !v`<
* @author Joa `]X>V,
*/ kFB
public class UserDAOImpl extends BaseDAOHibernateImpl vbNBLCwug
2|L&DF:G
implements UserDAO { PdCEUh\>y
9my^Y9B
/* (non-Javadoc) q7!{?\T%
* @see com.adt.dao.UserDAO#getUserByName ] @'!lhLi
xUvs:
(java.lang.String) 99S^f:t
*/ dscgj5b1~
publicList getUserByName(String name)throws . ^u,.
<!+Az,-
HibernateException { T|p"0b A
String querySentence = "FROM user in class yZRzIb_
N$DkX)Z
com.adt.po.User WHERE user.name=:name"; VnzZTGs
Query query = getSession().createQuery d@^ZSy>L2
u"8yK5!
(querySentence); Q@niNDaW2
query.setParameter("name", name); +:f"Y0
return query.list(); hc1N~$3!G
} `gJ(0#ac
Gq6*SaTk
/* (non-Javadoc) TJN4k@\$2
* @see com.adt.dao.UserDAO#getUserCount() Si7*& dw=
*/ s S
Mh`4'
publicint getUserCount()throws HibernateException { (ZGbhMK
int count = 0;
<Uur^uB
String querySentence = "SELECT count(*) FROM y(&Ac[foS}
6mE\OS-I
user in class com.adt.po.User"; iwq!w6+
Query query = getSession().createQuery GeqPRah
:Al!1BJQ
(querySentence); 2T1q?L?]
count = ((Integer)query.iterate().next (mOtU8e
dveiQ
()).intValue(); 5\v3;;A[
return count; CAe!7HiR
} 92c HwWZ!
9ati`-y2
/* (non-Javadoc) ~[
F`"
* @see com.adt.dao.UserDAO#getUserByPage H.;Q+A,8^
pw#-_
(org.flyware.util.page.Page) @L`jk+Y0vF
*/ K'xV;r7Nt
publicList getUserByPage(Page page)throws S@Y39
7nSxi+6e
HibernateException { fOHxtHM
String querySentence = "FROM user in class 5N]"~w*
9^x> 3Bo
com.adt.po.User"; UBs4K*h|
Query query = getSession().createQuery vIvIfE
Y@v>FlqI{
(querySentence); YQ}o?Q$z
query.setFirstResult(page.getBeginIndex()) . me;.,$#
.setMaxResults(page.getEveryPage()); .X&9Q9T=#
return query.list(); ^pS~Z~[d/
}
jo7\`#(Q
t:S+%u U
} LP-o8c
=AT."$r>
So6x"1B
IgzQr >
3R/bz0 V>
至此,一个完整的分页程序完成。前台的只需要调用 'R)Tn!6
KoRV%@I
userManager.listUser(page)即可得到一个Page对象和结果集对象 rjP/l6
~'
0_/[k*Re
的综合体,而传入的参数page对象则可以由前台传入,如果用 y}
'@R$
>l m&iF3y
webwork,甚至可以直接在配置文件中指定。 [Pp'Ye~K@c
J4'eI[73
下面给出一个webwork调用示例:
y7{?Ip4[
java代码: 0J|3kY-n>
cNrg#Asen&
/QQ*8o8
/*Created on 2005-6-17*/ Q59suL
package com.adt.action.user; ?0.NIu,,o
+ 3gp%`c4
import java.util.List; =wJX0A|
K"6vXv4QO
import org.apache.commons.logging.Log; iscz}E,Y
import org.apache.commons.logging.LogFactory; #Z #-Ht
import org.flyware.util.page.Page; X2_=agEP
}ZI7J
import com.adt.bo.Result; V9vTsmo(
import com.adt.service.UserService; Iv *<La
import com.opensymphony.xwork.Action; \['Cj*e k
/FII07V
/** :s,Z<^5a)g
* @author Joa n<,BmVQ
*/ SM'|+ d
publicclass ListUser implementsAction{ 0K+ne0I
do_[&
privatestaticfinal Log logger = LogFactory.getLog 3$tdwe$S
|)&%A%m
(ListUser.class); GyIV
Hby
Xvv6~
private UserService userService; =l6mL+C
#E?4E1bnB
private Page page; %>yL1BeA4
\+etCo
privateList users; M:8R-c#![
`uFdwO'DD
/* {ax:RUQxy
* (non-Javadoc) /z!%d%"
* }C:r9?T
* @see com.opensymphony.xwork.Action#execute() E./2jCwI(Y
*/ O^.#d
publicString execute()throwsException{ ~&T~1xsFJ
Result result = userService.listUser(page); \m,PA'nd/
page = result.getPage(); LLo;\WGZ
users = result.getContent(); dG{A~Z z
return SUCCESS; CAJ'zA|o
} r$1Qf}J3=
|>Vb9:q9Po
/** ok[i<zl;'
* @return Returns the page. 97]E1j]
*/ .8R@2c`}Cs
public Page getPage(){ m*pJBZxd
return page; w(/S?d
} AdEMa}u6
^y::jK
/** 53D]3
* @return Returns the users. %{|p j
+
*/ \bcLiKE{
publicList getUsers(){ fl(wV.Je|
return users; t!XwW$@
} vt8By@]:
n[z+<VGwC
/** Z~CjA%l
* @param page sT)CxOV
* The page to set. m@c)Xci
*/ rH-23S
publicvoid setPage(Page page){ NOva'qk
this.page = page; %Zi} MPx
} $I=~S[p
N['.BN
/** tA;}h7/Lc~
* @param users 8=l%5r^cq
* The users to set. kj_c%T
]/
*/ ,prf;|e?
publicvoid setUsers(List users){ XTyxr
this.users = users; t# i#(H
} k:;r2f
\dVOwr
/** v+XJ*N[W
* @param userService (HVGlw'`
* The userService to set. X8|,
*/ C _Dn{
publicvoid setUserService(UserService userService){ ;+%rw 2Z,B
this.userService = userService; r&CiSMS*
} t0S1QC+
} p+eh%2Jm
se)TzI^]b@
ep8
1#x0 q:6
Da|z"I
x
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, mt
.sucT
@]j1:PN-
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 A"]YM'.
f#;> g
么只需要: .nJz G
java代码: :X=hQ:>P
V88p;K$+
vaLSH
xi
<?xml version="1.0"?> 7dWS
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork qPNR`%}Q
R_C)
1.0//EN" "http://www.opensymphony.com/xwork/xwork- _f83-':W6
^('wy};
1.0.dtd"> %EH)&k
&~CI<\o P
<xwork>
];m_4
LV Ge]lD
<package name="user" extends="webwork- Xvu(vA
tw;}jh
interceptors"> 1Mzmg[L8
[JiH\+XLPs
<!-- The default interceptor stack name f|5co>Hk
-RwE%cr
--> fC`&g~yK'
<default-interceptor-ref c{|p.hd
$FV NCFN%
name="myDefaultWebStack"/> ]^E?;1$f?
9{l}bu/u
<action name="listUser" dPlV>IM$z
T)/eeZ$
class="com.adt.action.user.ListUser"> 0J9x9j`&j
<param P:c w|Q
M3\AY30L
name="page.everyPage">10</param> 54T`OE
=
<result N8jIMb'<
<~)P7~$d?p
name="success">/user/user_list.jsp</result> k[xSbs'D
</action> Y2AJ+
|
[n@]
r2g)3
</package> u`W2+S
SUiOJ[5,
</xwork> [txE .7p
j#|ZP-=1_
-@'FW*b
Lbgi7|&
.v
K-LHs
XFl6M~ c
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 }bxs]?OW>
c 9Mz]1@f
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/-=%g >HA
d]9z@Pd
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 2/?|&[
ch]IzdD
kiEa<-]
{7[Ox<Ho
N2G{<>=
我写的一个用于分页的类,用了泛型了,hoho $'v U2L
F9PxSk_\9
java代码: V~GDPJ+
3";q[&F9y
MgZ/(X E
package com.intokr.util; 4#D,?eA7
dtDFoETz
import java.util.List; /ZX}Nc g
6ujWNf
/** m67V_s,7B
* 用于分页的类<br> 10&8-p1/mc
* 可以用于传递查询的结果也可以用于传送查询的参数<br> [^iN}Lz
* F9^S"qv$
* @version 0.01 203s^K61
* @author cheng
mh%VrAq
*/ z{q`G wW
public class Paginator<E> { ).O)p9
privateint count = 0; // 总记录数 KNl$3nX
privateint p = 1; // 页编号 0GL M(JmK
privateint num = 20; // 每页的记录数 ~%oR[B7=|
privateList<E> results = null; // 结果 Eci\a]
Pz7XAcPQ(
/** X$
D6Ey
* 结果总数 HS$r8`S?)
*/ 3]hWfj1m2
publicint getCount(){ '/p4O2b,
return count; ?6!LL5a.
} P}iE+Z3
+`4A$#$+y
publicvoid setCount(int count){ T{"(\X$
this.count = count; 4+n\k
} )X7A
?dTD\)%A
/** pH;%ELZ
* 本结果所在的页码,从1开始 %b0*H_ok7
* Jm@oDME_E
* @return Returns the pageNo. 4H/OBR
*/ g(g& TO
publicint getP(){ [g,}gyeS(
return p; \V:^h[ad
} z:O8Ls^\T
)7@0[>
/** )oZ dj`
* if(p<=0) p=1 lZ0 =;I
* f$( e\++
* @param p ]:;&1h3'7
*/ Gj*9~*xm(
publicvoid setP(int p){ %O<BfIZ
if(p <= 0) x-c"%Z|
p = 1; bt *k.=p
this.p = p; d9ihhqq3}
} Bvj0^fSm
#ob/p#k
/** rqq1TRg
* 每页记录数量 :k"]5>(^
*/ Dq xs+
publicint getNum(){ s2?&!
return num; L];b<*d
} Ac6=(B
%y@AA>x!
/** g0H[*"hj
* if(num<1) num=1 'qi}|I
*/ ^Cmyx3O^
publicvoid setNum(int num){ 9Flb|G%
if(num < 1) E^PB)D(.
num = 1; eyaNs{TV
this.num = num; llDJ@
} 8t`?#8D}
0x7'^Z>-oe
/** 8MBAtVmy
* 获得总页数 e!`i3KYn"
*/ !k%#R4*>
publicint getPageNum(){ q4q6c")zp
return(count - 1) / num + 1; VQI3G
} K,]=6Rj
R+| h w;
/** )[ ,A_3E
* 获得本页的开始编号,为 (p-1)*num+1 ax2B ]L2
*/ ]Dzlp7Y}
publicint getStart(){ =sFTxd_"iQ
return(p - 1) * num + 1; mmsPLv6
} 5xde;
l0]
EX>"E
/** 4 :=]<sc,
* @return Returns the results. DlT{`
*/ BY*Q_Et
publicList<E> getResults(){ E4!Fupkpf
return results; \jA~9
} .543N<w
pp2~Meg
public void setResults(List<E> results){ (t.Nk[
this.results = results; x"(KBEK~
} JRFtsio*
+V+a4lU14
public String toString(){ /=h` L,
StringBuilder buff = new StringBuilder [Q =Nn
"3hMq1NQ`g
(); *A< 5*Db:F
buff.append("{"); ckn~#UE=
buff.append("count:").append(count);
5uf a
buff.append(",p:").append(p); DMS!a$4
buff.append(",nump:").append(num); *H122njH+T
buff.append(",results:").append F/Pep?'
IB<d
(results); t
Pf40`@
buff.append("}"); jal-9NV)!
return buff.toString(); HThcn1u~^b
} J;%Xfx]
_|]x2xb)
} m,S{p<-h
.2pK.$.
2%>FR4a