Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ~?:Xi_3Lo
SAUG+{Uq
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 f= 33+8I
s AlOX`t
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 C''[[sw'K
M<3m/l%`Y
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 )"&\S6*!
X m%aT
。 #W[C;f|,
#yR@.&P
分页支持类: 0r ilg
Qh,Dcg2ZM"
java代码: ka[%p, H
m95;NT1N/g
X{;3gN
package com.javaeye.common.util; 42 &m)
R\>=}7
import java.util.List; @+^5ze\
d;LBV<Z?
publicclass PaginationSupport { 4e9'yi
.>|]Lo(=l
publicfinalstaticint PAGESIZE = 30; nY=]KU
6l?\iE
privateint pageSize = PAGESIZE; 6ZwFU5)QE/
^]1M8R,
privateList items; te8lF{R
GeCyq%dN
privateint totalCount; q
NE(@at
6j=a
privateint[] indexes = newint[0]; N!#TK9
3&vUR(10
privateint startIndex = 0; 4@ =l'Fw
zFGZ;?i
public PaginationSupport(List items, int h]#bPb
K)8N8Js(
totalCount){ <aEY=IF4
setPageSize(PAGESIZE); `PeWV[?
setTotalCount(totalCount); qra5&Fvb
setItems(items); O)WduhlGQ
setStartIndex(0); hu''"/raM
} _b1w<T
`
z4[S02s
public PaginationSupport(List items, int D_4UM#Tw
}Qo:;&"3
totalCount, int startIndex){ *C n `pfO
setPageSize(PAGESIZE); I%fz^:[#<
setTotalCount(totalCount); cWG?`6xU&
setItems(items); =;"$t_t
setStartIndex(startIndex); _/zK^S)
} %knPeo&
^6[o$eY3
public PaginationSupport(List items, int _LUTIqlvi
0/Wo":R:
totalCount, int pageSize, int startIndex){
S9Ka
setPageSize(pageSize); 7ZVW7%,zF
setTotalCount(totalCount); "mm|0PUJ
setItems(items); 3d0Yq
setStartIndex(startIndex); 'WW['
} {_i.IPp~
h#iFp9N
publicList getItems(){ E5}wR(i,4
return items; |p1pa4%}
} [rt+KA
D3+UV+&R/
publicvoid setItems(List items){ $2j?Z.yEG
this.items = items; .g6DKjy>
} e~,/Z\i
(YJ]}J^
publicint getPageSize(){ N<54_(|X
return pageSize;
>v DD.
} nxc35
-UM5&R+o
publicvoid setPageSize(int pageSize){ ~!w()v n
this.pageSize = pageSize; -gP4| r8&
} 75pz' Cb
(y xrK
publicint getTotalCount(){ 2-3|0<`
return totalCount; 'h6Vj6
} #!%\97ZR
!y>MchNv
publicvoid setTotalCount(int totalCount){ |# zznT"
if(totalCount > 0){ ktr l |
this.totalCount = totalCount; 2_4m}T3
int count = totalCount / y ~
A]
Z-!W#
pageSize; W1UG\d`2
if(totalCount % pageSize > 0) +=y ktf
count++; :W/,V^x}
indexes = newint[count]; MO{6B#(<F
for(int i = 0; i < count; i++){ k-(hJ}N
indexes = pageSize * I<I?ks
$z9z'^HqO
i; ZZa$/q"
} J@{yWgLg
}else{ #0HF7C3
this.totalCount = 0; (\si/&
} |xTf:@hgHf
} U~SOHfZ%(
Q-[^!RAK?
publicint[] getIndexes(){ *n)3y.s
return indexes; kMS[
} Sdc;jK 9d!
Uv6#d":f;
publicvoid setIndexes(int[] indexes){ /:a~;i
this.indexes = indexes;
9Q".166
} EiY i<Z_S
Kt%`]Wp
publicint getStartIndex(){ vXnTPjbE
return startIndex; lA39$oJ
} 'iN8JO>
7oPBe1P,K+
publicvoid setStartIndex(int startIndex){ V*U7-{ *a
if(totalCount <= 0) H~c+L'=
this.startIndex = 0; 46'EZ@#s
elseif(startIndex >= totalCount) .cA[b
this.startIndex = indexes _4z>I/R>Z
V%pdXM5
[indexes.length - 1]; '}c0:,5
elseif(startIndex < 0) A+j~oR
this.startIndex = 0; I\sCH
else{ ZYBNS~Q
this.startIndex = indexes (tEW#l'}
r+HJ_R,5A
[startIndex / pageSize]; >P5 EW!d
} d]h[]Su/?
} _OT kv6;4n
0[0</"K%1m
publicint getNextIndex(){ +MOUO$;fGt
int nextIndex = getStartIndex() + hHoc7
?x]T&S{
pageSize; Y3[<
if(nextIndex >= totalCount) K:P gkc
return getStartIndex(); $cH'9W}3K
else 9Dd/g7
return nextIndex; >k^=+
} a2iaP
8(%iYs$
publicint getPreviousIndex(){ p`{9kH1m e
int previousIndex = getStartIndex() - BZsw(l4/0'
0;e>kz3o
pageSize; &&[j/d}J
if(previousIndex < 0) 2`t4@T
return0; +(r8SnRX
else dW!T.S
return previousIndex; eUqsvF}l!
} VX&KGG.6
u9m"{KnV
} Czb@:l%sc
[m!\ZK
Old5E&
=g/K>B
抽象业务类 X>F/0/
java代码: nb22bXt
G?=X!up(
" S#0QH%5
/** if:2sS9r
* Created on 2005-7-12 suPQlU>2sj
*/ u-j$4\'
package com.javaeye.common.business; CbS9fc&
6E@r9U
import java.io.Serializable; 2#6yO`?uo
import java.util.List; #(bMZ!/(
$CHri|
import org.hibernate.Criteria; 5@Ot@o
import org.hibernate.HibernateException; tB}&-U|t[~
import org.hibernate.Session; O,9KhX+
import org.hibernate.criterion.DetachedCriteria; z{``v|K
import org.hibernate.criterion.Projections; Y'bDEdeT
import K!HSQ,AC
z9&$Xao
org.springframework.orm.hibernate3.HibernateCallback; 398}a!XM
import qN}0$x>p
*"O7ml]
org.springframework.orm.hibernate3.support.HibernateDaoS ~;il{ym
gHvxmIG
upport; ?8b?{`@V
(tx6U.Oy
import com.javaeye.common.util.PaginationSupport; \ tF><
J03yFT,dF
public abstract class AbstractManager extends bb+-R_3Kd
[=7|LHjU
HibernateDaoSupport { 5RI"gf
2m[z4V@`
privateboolean cacheQueries = false; (6>8Dt 9[
wb.47S8
privateString queryCacheRegion; :=T+sT~
)g9Zw_3
publicvoid setCacheQueries(boolean `kVy1WiY
k[gO>UGB;
cacheQueries){ dilRL,
this.cacheQueries = cacheQueries; oh :g
} !d&K,k
o.keM4OQ
publicvoid setQueryCacheRegion(String N'i%9SBcg
M@E*_U!U
queryCacheRegion){ j0Kj>
this.queryCacheRegion = lBgf' b3$
|t!kD(~r
queryCacheRegion; }tua0{N:z
} 5|9,S
] 06LNE
publicvoid save(finalObject entity){ O!\P]W4r$
getHibernateTemplate().save(entity); iLws;3UX;x
} )d2 <;c
U_wn/wcLS
publicvoid persist(finalObject entity){ m@u!frE,
getHibernateTemplate().save(entity); &Op, ?\
} B<I%:SkF@
Gvb>M=9
publicvoid update(finalObject entity){ SirjWYap
getHibernateTemplate().update(entity); 8&IsZPq%l
} M-e!F+d{od
Tu?+pz`h
publicvoid delete(finalObject entity){ qb]n{b2
getHibernateTemplate().delete(entity); (Ub=sC
} [V|,O'X ~
{Uz@`QO3
publicObject load(finalClass entity, >8"oO[U5>
w-C~
Ik
finalSerializable id){ &BY%<h0c
return getHibernateTemplate().load }/nbv;)
AE={P*g
(entity, id); =!w5%|r.
} h3Nwxj~E
*`mPPts}
publicObject get(finalClass entity, 1XSA3;ZEc
$3[IlQ?
finalSerializable id){ : ^F+mQN
return getHibernateTemplate().get /`Yy(?,
J;W(}"cFq
(entity, id); Wb+^Ue
} %0fF_OU
lM86 *g 'l
publicList findAll(finalClass entity){ Sf);j0G,D
return getHibernateTemplate().find("from m2E$[g
<H<5E'm
" + entity.getName()); 7g[m,48{
} zlF*F8>m
4.I6%Bq$
publicList findByNamedQuery(finalString [ R+zzl&Zw
WPygmti}Be
namedQuery){ A{iI,IFe
return getHibernateTemplate veFl0ILd
&$?e D{
().findByNamedQuery(namedQuery); XKp.]c wP
} %C\Q{_ AS
xphw0Es
publicList findByNamedQuery(finalString query, r(h&=&T6
MlgE-Lm
finalObject parameter){ S~d_SU~>`
return getHibernateTemplate q>/#
P5V
2.ud P
().findByNamedQuery(query, parameter); S(9Xbw)T
} R $HIJM
LTj;e[
publicList findByNamedQuery(finalString query, 5!$m3j_,]?
gP"p7\
(
finalObject[] parameters){ %Fig`qX
return getHibernateTemplate @[#U_T- I
.j:.?v
().findByNamedQuery(query, parameters); /ZqBO*]
} CP_ ?DyWU
@qmONQ eb
publicList find(finalString query){ k$UgTZ
return getHibernateTemplate().find ("0@_05OH
}hrLM[
(query); 9w'3d@
} iwWy]V m7
!`q*{Ojx
publicList find(finalString query, finalObject fZL%H0&
v+U(
#"
parameter){ Uhfm@1 cz&
return getHibernateTemplate().find i/9QOw~
V#.;OtF]
(query, parameter); 8:;_MBt
} &o{I9MD
?P@fV'Jo
public PaginationSupport findPageByCriteria 0JQy-hpF
vn|u&}h
(final DetachedCriteria detachedCriteria){ @GqPU,RO
return findPageByCriteria 4b=hFwr[?
fN~kdm.
(detachedCriteria, PaginationSupport.PAGESIZE, 0); H1_XEcaM+*
} e`zEsLs@
((^jyQ
public PaginationSupport findPageByCriteria 4[a?..X
jIJVl \i]
(final DetachedCriteria detachedCriteria, finalint 0l3v>ty
vl*CU"4
startIndex){ 'Bb]<L`
return findPageByCriteria _=E))Kp{z
}[}u5T`w>
(detachedCriteria, PaginationSupport.PAGESIZE, NLFs)6\
.o91^jt
startIndex); #P *%FgROl
} S>}jsP:V
0}Rxe
public PaginationSupport findPageByCriteria <h|XB}s+
r@FdxsCnGM
(final DetachedCriteria detachedCriteria, finalint C-d|;R}Ww
ozH7c_ <
pageSize, $'e;ScH
finalint startIndex){ B 3|zR
return(PaginationSupport) `?LQd2p
'c5#M,G~
getHibernateTemplate().execute(new HibernateCallback(){ %41dVnWB^4
publicObject doInHibernate ]\5@N7h
:0IxnK(r&
(Session session)throws HibernateException { zy`4]w$Lj+
Criteria criteria = kRs[H xI3
?xh_qy;
detachedCriteria.getExecutableCriteria(session); J XKps#,(#
int totalCount = FP<RoA?W
9UTWq7KJ
((Integer) criteria.setProjection(Projections.rowCount xal,j*
kwNXKn/
()).uniqueResult()).intValue(); xb\(>7M6Y
criteria.setProjection !iUdej^tx
&&$/>[0=.
(null); lnL&v'{
List items = 6i[\?7O'0
3S1V^C-eBx
criteria.setFirstResult(startIndex).setMaxResults "wL~E Si
8+Al+6d|!
(pageSize).list(); S+>&O3m
PaginationSupport ps = EquNg@25W
84L!r
new PaginationSupport(items, totalCount, pageSize, >0)E\_ u
Ug^C}".&
startIndex); Pc{D,/EpR
return ps; Gp9>R~$
} pC(AM=RY!
}, true); VOwt2&mZ
} D *W+0
xou7j
public List findAllByCriteria(final Y<3s_
T[a1S ?_*T
DetachedCriteria detachedCriteria){ /k<*!H]KSg
return(List) getHibernateTemplate St,IWOmq"
j>gO]*BX~
().execute(new HibernateCallback(){ Y>t*L#i
publicObject doInHibernate ?"+'OOqik
s=#IoNh
(Session session)throws HibernateException { gJi11^PK
Criteria criteria = p9R`hgx
0K>rc1dy
detachedCriteria.getExecutableCriteria(session); ar+mj=m
return criteria.list(); ^T'+dGU`
}
j^KM
}, true); efMv1>{
} -qfd)A6]
+f\tqucI3
public int getCountByCriteria(final %_M B-
e;x`C
DetachedCriteria detachedCriteria){ nhk +9
Integer count = (Integer) SAs'u"EB
7qon:]b4
getHibernateTemplate().execute(new HibernateCallback(){ ./kmI#gaV
publicObject doInHibernate R8EDJ2u#
Wr`=P,
(Session session)throws HibernateException { x)G/YUv76
Criteria criteria = [=e61Z
L"zOa90ig
detachedCriteria.getExecutableCriteria(session); *-Lnsi^7v
return !f)'+_d
S)VuT0
criteria.setProjection(Projections.rowCount ( NjX?^
Y~=5umNSX
()).uniqueResult();
_+|*
} {0QD-b o
}, true); 8(KsU,%d
return count.intValue(); qfC9 {gu
} i/O!bq[o
} 1>a^Q
(n"M)
cWFvYF
Yc:b:\0}F6
Iay7Fkv
7 bsW7;C
用户在web层构造查询条件detachedCriteria,和可选的 1Od:I}@
P%Q}R[Q
startIndex,调用业务bean的相应findByCriteria方法,返回一个 kGc)Un?'{U
}E>2U/wpXY
PaginationSupport的实例ps。 \_x)E]D
q>Px
ps.getItems()得到已分页好的结果集 DLS-WL
ps.getIndexes()得到分页索引的数组 nkJ*$cT1o
ps.getTotalCount()得到总结果数 dUb(C1h
ps.getStartIndex()当前分页索引 L8bq3Q'p
ps.getNextIndex()下一页索引 ]-x#zp;=
ps.getPreviousIndex()上一页索引 BD4.sd+H,
;i:Uoyi
(Egykh>
/6gRoQ%j
GmAE!+"
apY m,_
u8o7J(aQsR
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 9\Xl3j!
q<hN\kBs
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 e1<28g
"a,Tc2xk
一下代码重构了。 Y%=A>~s*c:
WR'A%"qBwi
我把原本我的做法也提供出来供大家讨论吧: 'c &Bmd40
+bRL.xY
首先,为了实现分页查询,我封装了一个Page类: =PZs'K
java代码: g LpWfT29V
w_U5w
tD4IwX
/*Created on 2005-4-14*/ t9K.Jc0
package org.flyware.util.page; zv0RrF^
2tWUBt\,g
/** (O`=$e
* @author Joa +IS$Un
* r<|\4zIo/
*/ >F-J}P
publicclass Page { ._FgQ``PL
yaX,s4p
/** imply if the page has previous page */ Zfb:>J@h6
privateboolean hasPrePage; n]j(tP
#=O0-si]P
/** imply if the page has next page */ B;K{Vo:C
privateboolean hasNextPage; !)\`U/.W
xE6y9"}!h
/** the number of every page */ S0yPg9v
privateint everyPage; erqm=)
P$pl
/** the total page number */ P?0b-Qr$a
privateint totalPage; )bK<t
6]rrj
/** the number of current page */ zP9 HYS
privateint currentPage; /(}V!0\?
D!Gm9Pa}
/** the begin index of the records by the current E'r*
g{,
W6_3f-4g
query */ omRd'\ RO
privateint beginIndex; Q?Nzt;)!.
(c}0Sg
S[u<vHy
/** The default constructor */ )>[(HxvfJU
public Page(){ d>AVUf<o~
n]o+KT\
} -8pHjry'q
v5 9>
/** construct the page by everyPage =
Oq;
* @param everyPage \2+xMv)8
* */ 9J%>2AA
public Page(int everyPage){ S3J6P2P
this.everyPage = everyPage; ,LMme}FFeb
} &
9?vQq|%
C8t+-p
/** The whole constructor */ \`XJz{Lm]
public Page(boolean hasPrePage, boolean hasNextPage, =riP~%_ML)
aIfog+Lp
3oKqj>
int everyPage, int totalPage, *e8V4P
int currentPage, int beginIndex){ Fza)dJ7
this.hasPrePage = hasPrePage; @Td[rHl
this.hasNextPage = hasNextPage; 6Nl$&jL
this.everyPage = everyPage; <wSmfg,yF
this.totalPage = totalPage; 9m'[52{o
this.currentPage = currentPage; 4u(}eE
f7
this.beginIndex = beginIndex; 96PVn
} 1L9^N
pDKJLa
/** W*s`1O >
* @return 4]+ ^K`
* Returns the beginIndex. 6F(yH4
*/ 7"[lWC!As5
publicint getBeginIndex(){ m9q%l_
return beginIndex; |Ji?p>\~
} YT3QwN9
&x3"Rq_
/** Xt7'clr
* @param beginIndex z`Q5J9_<cV
* The beginIndex to set. PIr Uls0}
*/ Q72wg~% w
publicvoid setBeginIndex(int beginIndex){ f,-|"_5;
this.beginIndex = beginIndex; I;|Aiu*
} AnyFg)a<
P! 3$RO
/** 5m bs0GL
* @return Ey n3Vv?v
* Returns the currentPage. QO?ha'Sl
*/ /9yiMmr5W
publicint getCurrentPage(){ {&;b0'!Tf
return currentPage; L.Lt9W2fi
} pts}?
cp2fDn
/** HdLkof2i
* @param currentPage 7]^ }
* The currentPage to set. I^wj7cFo5
*/ FU [,,a0<<
publicvoid setCurrentPage(int currentPage){ [@y=%\%R
this.currentPage = currentPage; XnY}dsSO
} ]_=HC5"
8qc%{8
/** 'LOqGpmVc
* @return ^GAdl}
* Returns the everyPage. oy`m:Xp
*/ g:6yvEu$ -
publicint getEveryPage(){ ^&<*$Ai~
return everyPage; s7
KKH
w
} c%U$qao=c+
,C&>mv xA
/** N1Z8I:
* @param everyPage |{jAMC0#
* The everyPage to set. I[`2MKh
*/ !Q3Snu=
publicvoid setEveryPage(int everyPage){ ChW0vIL`
this.everyPage = everyPage; ?rOb?cu-
} ~pA;j7*
FKx9$B
/** p%ZiTrA1&D
* @return pd;-z
* Returns the hasNextPage. "@?|Vv,vn
*/ a"DV`jn
publicboolean getHasNextPage(){ Q)@1:(V/
return hasNextPage; O1ha'@qID
} ^hHeH:@
{UmCn>c
/** 8k1r|s@d
* @param hasNextPage ygW@[^g
* The hasNextPage to set. 'f}S,i +q
*/ aK&+p#4t
publicvoid setHasNextPage(boolean hasNextPage){ vedMzef[@>
this.hasNextPage = hasNextPage; _Ry.Wth
} 6uXW`/lvX
0oJ^a^|
/** 7qUtsDK
* @return nMa^Eq#
* Returns the hasPrePage. r:5Ve&~
*/ Vtg/,1KQ
publicboolean getHasPrePage(){ 1b7xw#gLx
return hasPrePage; ,SM- Z`'
} :I'Ezxv|
-Wn.@bz6B
/** '*XNgvX
* @param hasPrePage Q Bw
ZfX
* The hasPrePage to set. \l:g{GnoT
*/ |Hm'.-
publicvoid setHasPrePage(boolean hasPrePage){ ?iLd5 Z
this.hasPrePage = hasPrePage; ,?`1ve_K<
} IeB6r+4|
NslA/"*
/** H|)1T-%
* @return Returns the totalPage. :ky<`Jfr`
* 9$,gTU_a
*/ P{Z71a5
publicint getTotalPage(){ a!:8`X~[/$
return totalPage; V0 F30rK
} zn
?;>Bl
^!<7#kX
/** 3N"&P@/0x
* @param totalPage N
&[,nUd
* The totalPage to set. ]k:m2$le
*/ 8T)zB6ng
publicvoid setTotalPage(int totalPage){ W#L"5pRg
this.totalPage = totalPage; AMd)d^;
} cXY'>N
=[K)<5,@
} ]pV1T
= b!J)]
Uo}&-$ B
p}A4K#G
0c61q Q6
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 eM+;x\jo?
-z0{\=@#m
个PageUtil,负责对Page对象进行构造: ?a>7=)%AH
java代码: @5jG
B#6pQp$
G\+nWvV7
/*Created on 2005-4-14*/ L{LU@.;1
package org.flyware.util.page; vNt>ESPB
WQ}!]$<"y
import org.apache.commons.logging.Log; a9Fm Y`
import org.apache.commons.logging.LogFactory; iEviH>b5
jN%p5nZ^EK
/** 7vaN&%;E%
* @author Joa NceB'YG|
* t/*K#]26
*/ 7+a%ehwU
publicclass PageUtil { F> QT|
"Wk{ 4gS7l
privatestaticfinal Log logger = LogFactory.getLog r^A#[-VyNP
=b<<5N s
(PageUtil.class); N4H+_g|
Yc82vSG'
/** WYC1rfd=
* Use the origin page to create a new page As+;qNO
* @param page N
2"3~ #
* @param totalRecords W/r mm*
* @return {?/8jCVd
*/ `GQiB]Z
publicstatic Page createPage(Page page, int ,![Du::1
ZJ9Jf2 c
totalRecords){ P$3=i`X!nw
return createPage(page.getEveryPage(), VL7S7pb_
C5+`<
page.getCurrentPage(), totalRecords); So=nB} b[?
} oKYhE
aw/7Z`
/** M7DLs;sD
* the basic page utils not including exception FGwnESCC
:5S |x/
handler x$n~f:1Y
* @param everyPage 7<:Wq=e!r
* @param currentPage 3_MS'&M
* @param totalRecords V[Rrst0yo
* @return page +lW}ixt
*/ u\XkXS`
publicstatic Page createPage(int everyPage, int 8pPC 9ew\=
^.#X<8hr
currentPage, int totalRecords){
3kiE3*H
everyPage = getEveryPage(everyPage); 9Yl8ndP^E
currentPage = getCurrentPage(currentPage); /S]:dDY9K
int beginIndex = getBeginIndex(everyPage, qB F!b0lr
)[^y
t0%
currentPage); \-
=^]]b=
int totalPage = getTotalPage(everyPage, sm;E2BR$
`
{OO*iZ.O
totalRecords); OK-sT7But
boolean hasNextPage = hasNextPage(currentPage, E69:bQ94u
PZuq'^p
totalPage); (/U)>%n
boolean hasPrePage = hasPrePage(currentPage); Jq$_=X&
5fu+rU-#
returnnew Page(hasPrePage, hasNextPage, ,\lYPx\P[
everyPage, totalPage, %o@['9U[j
currentPage, 2f19W#
'0
Z'Exw-ca
beginIndex); ACigeK^C}E
} d&|z=%9xl
6F*-qb3
privatestaticint getEveryPage(int everyPage){ heL$2dZ5H
return everyPage == 0 ? 10 : everyPage; Tr8AG>
} 2(m85/Hr\;
RCBf;$O
privatestaticint getCurrentPage(int currentPage){ :8^M5}
return currentPage == 0 ? 1 : currentPage; O3kg
} ~h)@e\Kc
6?V<BgCC
privatestaticint getBeginIndex(int everyPage, int a)!![X?\
9-
xlvU,o
currentPage){ mRhd/|g*
return(currentPage - 1) * everyPage; ><NI'q*cQ
} <0u\dU
vi]r
privatestaticint getTotalPage(int everyPage, int `DLp<_z>
zoZ<)x=;
totalRecords){ ic*->-!
int totalPage = 0; 8!4~T,9G
5Vp;dc
if(totalRecords % everyPage == 0) JEWL)
totalPage = totalRecords / everyPage; *jk3 \KaoV
else &?.n2+T+
=
totalPage = totalRecords / everyPage + 1 ; (C daE!I4Q
Go>wo/Sb
return totalPage; DR:8oo&E
} fdlvn*H
]} 61vV
privatestaticboolean hasPrePage(int currentPage){ No`|m0 :j
return currentPage == 1 ? false : true; .sM<6;
} #D+7TWDwNt
C:`;d&d
privatestaticboolean hasNextPage(int currentPage, 'yp>L|
M.>^{n$
z
int totalPage){ 0b/ir 2
return currentPage == totalPage || totalPage == @j O4EEe:
v*E(/}<v
0 ? false : true; 5Sr4-F+@%
} U1ZIuDg'E
KH7VR^;mk
qysTjGwa]
} iI5+P`sE&J
s\[LpLt
KZ=u54
&V'519vmoZ
t3PtKgP-6
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。 7vn%kW=$
L}'Yd'
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 &&=[Ivv
Cye
T]y
做法如下: 4/S=5r}
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 UMV)wy|j
@;vNX*-J
的信息,和一个结果集List: lT2 4JhJ#
java代码: M)&Io6>
w|IjQ1{
! Tx&vtq
/*Created on 2005-6-13*/ TZ[Zm
package com.adt.bo; bS.s?a
33Jd!orXU
import java.util.List; [J^
Cyq?5\ a
import org.flyware.util.page.Page; -LtK8wl^
HPrq1QpK
/** q:I$EpKf?Q
* @author Joa C{EAmv'
*/ oM!xz1kVL
publicclass Result { :.kZR;
0}{'C5
private Page page; 7 8Vcu'j&_
{_?rh,9q
private List content; S,)d(g3>
j~;;l!({i
/** H~noJIw#
* The default constructor H{l)
*/ ^$v3eKA
public Result(){ rLU'*}
super(); -KH)J
} T*?s@$)m4
k.<3HU
/** ?38lHn`FyQ
* The constructor using fields X'f.Q
* z-dFDtiA
* @param page -w1@!Sdd
* @param content J'b<z.OW
*/ > _ <'D
public Result(Page page, List content){ @@@=}!<H=
this.page = page; =pcF:D#+
this.content = content; &?0:v`4Y
} =<c#owe:m
Xa," 'r
/** ~. YWV
* @return Returns the content. |?d#eQ9a
*/ #sTEQjJ,J
publicList getContent(){ fmfTSN(Q~`
return content; VIC0}LT0R
} Z&Y=`GOI
$<nCXVqL,
/**
%@Oma
* @return Returns the page. &$'z
*/ oRM)%N#
public Page getPage(){ Yw'NX5#)g
return page; ~gE:-
} -`+<{NHv\
J NVr
/** lhH`dG D
* @param content |F[=b'?
* The content to set.
\(~wZd
*/ !ErH~<f%K
public void setContent(List content){ 6KHN&P
this.content = content; R\mR $\cS
} x}TS
p8}(kHUp(
/** QSw<%pcJE@
* @param page ht =P\E
* The page to set. R'}95S<
*/ ~1
~Xfo>
publicvoid setPage(Page page){ S?ujRp
this.page = page; ehNzDr\s
} 5O<>mCF
} uR;gVO+QC
#m<tJnEO
~g#r6pzN-
4dawg8K`9
#3$\Iu
2. 编写业务逻辑接口,并实现它(UserManager, izgp*M,
@{hd{>K*
UserManagerImpl) Bc7V)YK
java代码: dY7'OAUyVl
7ZxaPkIu&%
urBc=3Rz
/*Created on 2005-7-15*/ rH8@69,B
package com.adt.service; B9R(&<4
1x)ZB~L
import net.sf.hibernate.HibernateException; %" D%:
gF?[rqz{
import org.flyware.util.page.Page; N8toxRu
KLoE&ds
import com.adt.bo.Result; JyL a#\ R
O.G'?m<:#
/**
O.`Jl%
* @author Joa ko;>#::
*/ =U8Ek;Drp
publicinterface UserManager { );V2?G`/
S! Rc|6y%
public Result listUser(Page page)throws {-3L IO
O7d$YB_'
HibernateException; 7hP<f}xL
({r*=wAP
} kIHDeo%K}
<%.5hCTp97
VKp*9%9
fhPkEvJ
vhbDb)J
java代码: O.aG[wm8
cH'
iA.
-l~Z0U>^
/*Created on 2005-7-15*/ W%<LTWOc
package com.adt.service.impl; 2. G=8:l
b-ll
import java.util.List; MP Z3D9
v
^[39*8
import net.sf.hibernate.HibernateException; F{06 _T
{]_uMg#!
import org.flyware.util.page.Page; [^CV>RuO
import org.flyware.util.page.PageUtil; [.se|]t7X
Od+6 -J
import com.adt.bo.Result; PZxAH9 S?
import com.adt.dao.UserDAO; <+MyZM(z>
import com.adt.exception.ObjectNotFoundException; ]i(-I <`
import com.adt.service.UserManager; 8Jf.ECQT
9.'h^#C
/** > fnh+M
* @author Joa *IgE)N>
*/ De7Ts
publicclass UserManagerImpl implements UserManager { =4V&*go*\
ZkL8 e
private UserDAO userDAO; dQoYCS}IaV
4[Z\
?[
/** f-DL:@crU
* @param userDAO The userDAO to set. Jk@]tAwoM
*/ 7C#`6:tI
publicvoid setUserDAO(UserDAO userDAO){ {3;AwhN0H
this.userDAO = userDAO; rX_@Ihv'
} X%z }VA
valtev0<
/* (non-Javadoc) L,y6^J!
* @see com.adt.service.UserManager#listUser #^m0aB7r
=qN2Xg/
(org.flyware.util.page.Page) 7Q\|=$2
*/ 8!.ojdyn
public Result listUser(Page page)throws +]=e;LN $0
EY*(Bw
HibernateException, ObjectNotFoundException { R1Sy9x .
int totalRecords = userDAO.getUserCount(); HhO".GA
if(totalRecords == 0) oFOnjK"|F
throw new ObjectNotFoundException %ZHP2j
%~
"KcA
("userNotExist"); n>@oBG)!
page = PageUtil.createPage(page, totalRecords); >WY#4
List users = userDAO.getUserByPage(page); DN4$Jva
returnnew Result(page, users); r0p w_j
} YK|bXSA[
[MuEoWrq(}
} ),%6V5a+E
wFG3KzEq ~
*s@Qtgu
U
qG
.:@T
{vAE:W.s
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 V_plq6z
+ QQS={
询,接下来编写UserDAO的代码: 06jqQ-_`h
3. UserDAO 和 UserDAOImpl: Aw&tP[N[
java代码: *#TUGfwy
.<kqJ|SVi
KNH1#30 K
/*Created on 2005-7-15*/ v<Bynd-
package com.adt.dao; ECv)v
l5L.5$N
import java.util.List; E=){K
UH3sH
t
import org.flyware.util.page.Page; pp9Zb.D\
mPq$?gdp
import net.sf.hibernate.HibernateException; wAnb
Di{W
!w&kyW?e
/** 2^?:&1:
* @author Joa apE
*/ n3J53| %v
publicinterface UserDAO extends BaseDAO { cwGbSW$t
NcY608C
publicList getUserByName(String name)throws }9nDo*A"}
9"g6C<
HibernateException; R8.CC1Ix
K~ ;45Z2
publicint getUserCount()throws HibernateException; 1S@vGq}
JxyB(
publicList getUserByPage(Page page)throws q^6 +!&"
A*W)bZs.
HibernateException; 6e7{Iy
DxJX+.9K9
} 'Ei;^Y 1e
fS^!ZPe1
zt^48~ry
2t $ j
@LJpdvb
java代码: 'M3">$N
,t1abp{A
ou
%/l4dC
/*Created on 2005-7-15*/ [s<^&WM/
package com.adt.dao.impl; L~ s3b
!UFfsNiXZ
import java.util.List; .^b;osAU
:O5og[;b
import org.flyware.util.page.Page; ZyEHzM{$
%vBhLaE
import net.sf.hibernate.HibernateException; D %JlbH8
import net.sf.hibernate.Query; ?McQr1
PTj&3`v
import com.adt.dao.UserDAO; N/GQt\tV<
41fJ%f`
G
/** {[+2n]f_G
* @author Joa Q
X%&~
*/ ,m,)I
public class UserDAOImpl extends BaseDAOHibernateImpl [TNj;o5J
s: 3z'4oX
implements UserDAO { 6m6zA/
<8,cuX\
/* (non-Javadoc) I* VCpaA
* @see com.adt.dao.UserDAO#getUserByName a')|1DnR
^B+!N;
(java.lang.String) !+:ov'F
*/ \e`~i@) ~Z
publicList getUserByName(String name)throws }x&N^Ky3c
Un6/e/6,
HibernateException { Xt#1Qs
String querySentence = "FROM user in class H{t_xL)k.
cHa]xmy%r'
com.adt.po.User WHERE user.name=:name"; t=xOQ8
Query query = getSession().createQuery ntmyNf?;
f3UXCp
(querySentence); C)cwAU|h#
query.setParameter("name", name); /Wf^hA
return query.list(); F4e:ZExJ
}
TT-h;'nJ
ApjOj/
/* (non-Javadoc) e)?Fi
* @see com.adt.dao.UserDAO#getUserCount() R6=$u{D
*/ ,\v91 Rp~?
publicint getUserCount()throws HibernateException { &7_Qd4=08w
int count = 0; Ja
,Cvt
String querySentence = "SELECT count(*) FROM _!|/
;Nk
pJ
?~fp
user in class com.adt.po.User"; >"Q@bQ:e
Query query = getSession().createQuery t+Op@*#%
}6 K^`!
(querySentence); /y>>JxAEb
count = ((Integer)query.iterate().next pAk/Qxl3eo
D\e8,,H
()).intValue(); x|{IwA9
return count; G}9=)
} #]'rz,E<
san,|yrMn
/* (non-Javadoc) r#6_]ep}<'
* @see com.adt.dao.UserDAO#getUserByPage w;l<[q?_
Q3"}Hl2
(org.flyware.util.page.Page) CA +uKM^"6
*/ %8~3M75$
publicList getUserByPage(Page page)throws $U/YR&vcw
{8I. `U
HibernateException { }cN@[3v
String querySentence = "FROM user in class pD&&l!i&[
D_8x6`z
com.adt.po.User"; /6_|]ijc
Query query = getSession().createQuery SvR7eC
5 QO34t2
(querySentence); %sRUh0AL
query.setFirstResult(page.getBeginIndex()) _@R0x#p5M
.setMaxResults(page.getEveryPage()); K).n.:vYZ
return query.list(); )IJQeC
} *FJZiPy
YX*Qd$chZ
} OaL\w
D^
7h)iu9j
K+6e?5t
qL94SW;
)TmHhNo
至此,一个完整的分页程序完成。前台的只需要调用 ^OErq&`u
CXCpqcC
userManager.listUser(page)即可得到一个Page对象和结果集对象 Dnc<sd;
xGI, Lk+
的综合体,而传入的参数page对象则可以由前台传入,如果用 ?@n/v
F
6_4D9 W
webwork,甚至可以直接在配置文件中指定。 <`0h|m'U
i9=&;_z
下面给出一个webwork调用示例: $O^v]>h
java代码: ./$cMaDJ
fJWC)E
C
XHy.&Vt
/*Created on 2005-6-17*/ *x)8fAr
package com.adt.action.user; TW^/sx
Lq>&d,F06)
import java.util.List; z.rh]Zq
@ps1Dr4s
import org.apache.commons.logging.Log; 1 tR_8lC
import org.apache.commons.logging.LogFactory; C^)*Dsp
import org.flyware.util.page.Page; Zec <m8~
6b!F 1
import com.adt.bo.Result; OnWx#84
import com.adt.service.UserService; w4LScvBg
import com.opensymphony.xwork.Action; 'L{8@gqi
(@#M!'
/** LjU'z#
* @author Joa Oq3A#6~
*/ 4Yl;
publicclass ListUser implementsAction{ lHV[Ln`\x
?i`l[+G
privatestaticfinal Log logger = LogFactory.getLog L_w+y
!s@Rok
(ListUser.class); ^3hn0DVQ
e]Zngt?b
private UserService userService; |!F5.%PY
A?G^\I~v
private Page page; !yhh8p3
aAy'\T$x.
privateList users; A 8 vbQ
6&bIXy
/* !a~`Bs$'jr
* (non-Javadoc) yObuWDA9
*
al`3Lu0
* @see com.opensymphony.xwork.Action#execute() @JW@-9/
*/ *Y@nVi
publicString execute()throwsException{ RyRpl*^
Result result = userService.listUser(page); Pm$q]A~
page = result.getPage(); I7&_Xr
users = result.getContent(); e${>#>
return SUCCESS; {hJXj,
} M?/jkc.8H
M4WiT<|]R
/** m E^o-9/
* @return Returns the page. 4tx|=;@0
*/ 0 P[RyQI
public Page getPage(){ ?2Kt'1s#
return page; =tU{7i*+
} 9h0X &1u
2y%,p{="
/** |+$%kJR=
* @return Returns the users. ^'jEnN(
*/ eh[_~>w
publicList getUsers(){ we#wH-
return users; 'Z`$n8
} 76vy5R(.
~y$ !48o
/** Jxqh)l
* @param page F]mgmYD%
* The page to set. #oJ5k8Wy
*/ ;}z\i
publicvoid setPage(Page page){ u0`%+:]0
this.page = page; p!/[K6u
} Z#.f&K )xX
Yhp]x
/** bZx!0>h
* @param users M _LXg%
* The users to set. CU7F5@+
*/ ^2wLxXO6
publicvoid setUsers(List users){ VxzkQ}o
this.users = users; 6'W [{gzl
} +ki{H}G21
,&4qgp{)
/** i55x`>]&sb
* @param userService
{NJfNu
* The userService to set. Ix|~f1*%
*/ '$ef+@y
publicvoid setUserService(UserService userService){ qOaQxRYm%Y
this.userService = userService; 0 'Vg6E]/
} s`Cy
a`
} "G:<7oTa
{iG@U=>
3zT_^;:L
|;A/|F0-e
VzJ5.mRQ
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, ;#MB7A
al+ #y)+
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 @t1V
o}c
1.q_f<U
么只需要: s6o>m*{
java代码: z>R#H/h+
Q o =Kqv
3gQPKBpc
<?xml version="1.0"?> Vpp;\
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork ^2]LV6I
W9oAjO NE
1.0//EN" "http://www.opensymphony.com/xwork/xwork- 8 ^B;1`#
~ 7)A"t
1.0.dtd"> saD-D2oj
*4|Hqa
<xwork> -|Kzo_"
v5
8q)=
<package name="user" extends="webwork- -A-tuyIsh"
?GBkqQ
interceptors"> Z2"?&pKV
hO[3 Z^X
<!-- The default interceptor stack name US{3pkr;I]
a ,7&"
--> @/UfDye
<default-interceptor-ref [\R>Xcu>
vVT?h
name="myDefaultWebStack"/> -6sW6;Q
2u?zO7W)-L
<action name="listUser" bAr` E
k
n8N,,+
class="com.adt.action.user.ListUser"> :c8n[+5
<param Lhh;2r/?78
Y\2|x*KwvF
name="page.everyPage">10</param> Q)af|GW$
<result {0!#>["<
OlD`uA
name="success">/user/user_list.jsp</result> X5
ITF)&
</action> ^/Sh=4=G
CVXytS?@x
</package> M`D$!BJr
UK*qKj.)
</xwork> 2q}..
HEA eo!
>5T_g2pkv
9j*0D("
)
uP\>vRy
kcB+ _
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 &@ 3m-Z
z&4~x!-_
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。 fRTo.u
T}7uew\v0<
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 j[6Raf/(n
)gR=<oa
1px\K8
nws"RcP+Z
FbACTeB
我写的一个用于分页的类,用了泛型了,hoho A<YsfDa_d
j;K#]
java代码: -Cid3~mX3
+Zk,2ri
^Jp*B;
package com.intokr.util; 0"[`>K~7a8
*Dr5O 9Y
import java.util.List; +pqM ^3t|y
pJ,@Y>
/** ED} 31L
* 用于分页的类<br> 5|$a =UIR
* 可以用于传递查询的结果也可以用于传送查询的参数<br> > 8]j
* rn.\tDeA
* @version 0.01 cy~oPj]j
* @author cheng j?n+>/sG,
*/ AW5iV3
public class Paginator<E> { y,+[$u7h
privateint count = 0; // 总记录数 @LLTB(@wR
privateint p = 1; // 页编号 \)m"3yY
privateint num = 20; // 每页的记录数 GIHpSy`z
privateList<E> results = null; // 结果 >qT 'z$
klWYuStZ
/** +yt6(7V*
* 结果总数 ;_<)JqUh
*/ J7-^F)lu-
publicint getCount(){ n<V1|X
return count; Uz8hANN0_
} r{+aeLu
)WR_
ug
publicvoid setCount(int count){ 8
|h9sn;P
this.count = count; oUW<4l
} u}H$-$jE
2pyt&'NJua
/** dYOF2si~%
* 本结果所在的页码,从1开始 gp|1?L54
* i+M*J#'
* @return Returns the pageNo. -.vDF?@G
*/ :,*eX' fH
publicint getP(){ 1(`M~vFDK
return p; hhRaJ
} &:?e &
jOtX
60;
/** DpL8'Dib
* if(p<=0) p=1 :_d3//|
* I^Qx/uTKw
* @param p ]jM^Z.mI+
*/ <6N_at3
publicvoid setP(int p){ T% CxvZ
if(p <= 0) [5 pCL0<c@
p = 1; W7G9Kx1Y
this.p = p; E*v]:kok
} ,J9}.}Hd
'UDBV
/** r25Z`X Z
* 每页记录数量 E;-qP)yU
*/ xDrV5bg
publicint getNum(){ M$CVQ>op:
return num; Q2~5"
} ! gp}U#Yv
K%,$ V,#
/** )}X5u%woV
* if(num<1) num=1 S6 }QFx
*/ = hX[
publicvoid setNum(int num){ Z6=~1'<X
if(num < 1) &`:rp!Lc
num = 1; ,# "(Z
this.num = num; ^Qh-(u`
} K=kH%ZK
, Fytk34
/** t;Wotfc[#0
* 获得总页数 No W!xLI
*/ B/YcSEY;
publicint getPageNum(){ 3;BvnD7
return(count - 1) / num + 1; VbxAd 2')
} V;[p438o
I($,9|9F
/** mCb 9*|
* 获得本页的开始编号,为 (p-1)*num+1 ~'BUrX\
*/ 8Uj:
publicint getStart(){ {
R*Y=Ie
return(p - 1) * num + 1; 6/y*2z;
} `Wf5
+J40wFI:y
/** )}|mDN&P
* @return Returns the results. -^fzsBL.
*/ 1~qm+nET\
publicList<E> getResults(){ 9A;6x$s
return results; wA0eG@xi)
} QAaF@Do
;6<zjV7}
public void setResults(List<E> results){ Y.
TYc;
this.results = results; _bQL[eXd
} Oc-u=K,B
ze"~Ird
public String toString(){ L[]^{ O
StringBuilder buff = new StringBuilder a@SUi~+3
i=da,W=0
(); 5^|"_Q#:
buff.append("{"); LkaG[^tfN
buff.append("count:").append(count); rUFFF'm\*a
buff.append(",p:").append(p); "#XtDpGk
buff.append(",nump:").append(num); y"R("j $
buff.append(",results:").append @DCJ}hud
g5TkD~w"
(results); a2 >[0_E
buff.append("}"); o4'v> b
return buff.toString(); $n*%v85
} 9[f%;WaS
o_:Qk;t
}
/Su)|[/'
zv9MHC
&
5vGioO