Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 -xcz+pHQ
8D n]`}ok
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 3?geJlD4
%d7iQZb>
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 q(r2\
p5H Mg\hT
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 *"4<&F
S
Rxli;blzi
。 U=yD!
uo{QF5z]
分页支持类: =az$WRV+7!
aFSZYyPxwv
java代码: ,f1wN{P
eP2 y U
Q.|2/6hD7[
package com.javaeye.common.util; {'ZnxK'
o&AUB`.9~
import java.util.List; k
Z3tz?Du
;4_n:XUgo;
publicclass PaginationSupport { ~J2Q0Jv
*@ o3{0[Z
publicfinalstaticint PAGESIZE = 30; @1+/r?b
WIGb7}egR
privateint pageSize = PAGESIZE; t!=S[
<7&b|f$CL
privateList items; k@Tt,.];
cnc$^[c
privateint totalCount; H{XW?O^@
ec0vg.>p
privateint[] indexes = newint[0]; ZRHTvxf
hB.dqv]^
privateint startIndex = 0; j;y|Ys)I
c1<g!Q&E
public PaginationSupport(List items, int 7/1S5yUr|
?~K2&eo
totalCount){ P:=ADW c
setPageSize(PAGESIZE); B';Ob
setTotalCount(totalCount); ]@P*&FRcZ
setItems(items); DEs?xl]zO
setStartIndex(0); t}tKm
} 4Klfnki
QXz!1o+"
public PaginationSupport(List items, int S&Sf}uK
zXD@M{
totalCount, int startIndex){
4[ra
setPageSize(PAGESIZE); S'O0'5U@
setTotalCount(totalCount); JU@$(
setItems(items); + ND9###
setStartIndex(startIndex); .3&m:P8zV
} ;H=6u
2ya`2 m
public PaginationSupport(List items, int *O5+?J Z!
Q.\>+4]1&&
totalCount, int pageSize, int startIndex){ QD<4(@c5|
setPageSize(pageSize); ?*@h]4+k'
setTotalCount(totalCount); dF,FH-
setItems(items); 5^dw!^d
setStartIndex(startIndex); `R> O5Rv
} t5k&xV=~
#
)yP>}ME
publicList getItems(){ o7+/v70D
return items; _~kcr5
} i/~J0qQ
A-io-P7qyj
publicvoid setItems(List items){ 39j d}]e
this.items = items; #r:`bQ0;
} rA`\we)
$ZU(bEUOG
publicint getPageSize(){ H1[aNwLr
return pageSize; zi
,Rk.
} h[]N=X
*LRGfk+h
publicvoid setPageSize(int pageSize){ ^sKXn:)
this.pageSize = pageSize; MUrY >FYgx
} 2z\F m/Z.
b{rmxtx
publicint getTotalCount(){ RtL<hD
return totalCount; ^ztf:'l@C
} CA4-&O"
o^?{j*)g
publicvoid setTotalCount(int totalCount){ WI6E3,ejB1
if(totalCount > 0){ K*9b `%
this.totalCount = totalCount; =;H'~
int count = totalCount /
%\cC]<>
@nP}q!y
pageSize; {Y[D!W2y
if(totalCount % pageSize > 0) DVJc-.x8
count++; VO Qt{v{1|
indexes = newint[count]; deoM~r9s
for(int i = 0; i < count; i++){ .y/b$|d,
indexes = pageSize * $D5U#
h+UscdUl
i; xgz87d/<:
} |^Es6 .~
}else{ 2M?lgh4"
this.totalCount = 0; .;b>
T
} uKy *N*}
} =T)2wcXBB
ib_Gy77Os
publicint[] getIndexes(){ X6 ,9D[Nw
return indexes; ^wa9zs2s;/
} bJm0
~ ""MeaM8[
publicvoid setIndexes(int[] indexes){ q4i8Sp>
this.indexes = indexes; Y14R"*t~
} {1aAm+
#!jRY!2Vt
publicint getStartIndex(){ s
vb4uvY
return startIndex; Rda1X~-g
} j>xVy]v= |
fWyDWU
publicvoid setStartIndex(int startIndex){ :dN35Y] a
if(totalCount <= 0) /8}+#h)[
this.startIndex = 0; Ye2];(M
elseif(startIndex >= totalCount) U.U.\
this.startIndex = indexes es[5B* 5
Db=>7@h3C
[indexes.length - 1]; $ud>Z;X=P
elseif(startIndex < 0) 1gm/{w6O
this.startIndex = 0; O&w3@9KJ?
else{ l;*lPRoW,
this.startIndex = indexes 1bg@[YN!;
@$d\5Q(G
[startIndex / pageSize]; AvE^
F1
} 8(5E<&JP
} `^L<db^A
I#t9aR+&
publicint getNextIndex(){ H?j-=Zka
int nextIndex = getStartIndex() + 9>3Ltnn0
U;{,lS2l
pageSize; MQ(/l_=zQ
if(nextIndex >= totalCount) W 8$=a
return getStartIndex(); mN{ajf)@
else B"m:<@ "
return nextIndex; Kxc$wN<
} O2]r]9sh*
8TZA T%4
publicint getPreviousIndex(){ _MbVF>JOx
int previousIndex = getStartIndex() - &8+6!TN7
v^W?o}W
pageSize; IIQ3|eZ
if(previousIndex < 0) v*~%x
return0; fslk7RlSKg
else NzAtdcwR
return previousIndex; mK40 f
} NB5L{Gf6-
OF<n T
} v?D
kDnta
W(a'^
#xe
ZqbM%(=z(`
1mn$Rh&dO
抽象业务类 xrVZxK:!
java代码: RO$@>vL
(
ssH=a
:+
9Ft>
/** 8U2wH
* Created on 2005-7-12 V> a3V'
*/ {<}I9D5
package com.javaeye.common.business; CDW(qq-zD
]2\2/~l
import java.io.Serializable; 39T&c85
import java.util.List; ys[i`~$
|<3Q+EB^
import org.hibernate.Criteria; K;y\[2;}e,
import org.hibernate.HibernateException; b6!Q!:GO&
import org.hibernate.Session; J4Z<Yt/
import org.hibernate.criterion.DetachedCriteria; y:|.m@
j1
import org.hibernate.criterion.Projections; ?Y0$X>nm
import x|v[Dxf]
M,\|V3s
org.springframework.orm.hibernate3.HibernateCallback; )/WA)fWkT
import _UBJPb@=U
$qlqWy-s
org.springframework.orm.hibernate3.support.HibernateDaoS p=-B~:
?%dCU~ z
upport; bpF@}#fT
(#-=y~%
import com.javaeye.common.util.PaginationSupport; /[|}rqX(
<[3lV)~t
public abstract class AbstractManager extends UQ$\
an'
;%rs{XO9
HibernateDaoSupport { oX2DFgz
oj^5G
]_<
privateboolean cacheQueries = false; KSgQ:_u4}
X[~f:E[1J
privateString queryCacheRegion; N
t>HztXd
P96Cw~<Q?
publicvoid setCacheQueries(boolean `z$uw
v;bM.OL
cacheQueries){ -Ty<9(~S
this.cacheQueries = cacheQueries; qN1e{T8u
} \9>g;qPg}
_yxe2[TD
publicvoid setQueryCacheRegion(String f`u5\!}=!
XgiI6-B~
queryCacheRegion){ ^;)SFmjg%
this.queryCacheRegion = (Y'UvZlM%P
\2gvp6
queryCacheRegion; r\l3_t
} e<L 9k}c
w~Tq|kU[
publicvoid save(finalObject entity){ ZM-/n>
getHibernateTemplate().save(entity); VRd:2uDS
} 2w x[D
~b>nCP8q
publicvoid persist(finalObject entity){ c69U1
getHibernateTemplate().save(entity); r>@ B+Xi
} c?p0#3%L#
h=v[i!U-eY
publicvoid update(finalObject entity){ [NCXn>Z
getHibernateTemplate().update(entity);
+eDN,iv
} Imh2~rw;
}"&n[/8~
publicvoid delete(finalObject entity){ f*|8n$%
getHibernateTemplate().delete(entity); %)<oX9E
} OUlxeo/
I*+LJy;j
publicObject load(finalClass entity, P;L)1 g
uHUvntr
finalSerializable id){ fw:7Q7
qo
return getHibernateTemplate().load 2rR@2Vsw2
B7Ki@)
(entity, id); Eo7 _v
} 0,1L e$)6
@wYQLZ
publicObject get(finalClass entity, PEX26==
_q$0lqq~u
finalSerializable id){ %2@ Tj}xa
return getHibernateTemplate().get |z!q
r}i
?8wwd!)x%
(entity, id); 7GBZA=J
} d5w_[=9U
A=v lC?&Z
publicList findAll(finalClass entity){ Ad}-I%Ie
return getHibernateTemplate().find("from .^[fG59
Jo7fxWO_g
" + entity.getName()); DU/9/ I?~
} 2_oK5*j
Zzw}sZ?8
publicList findByNamedQuery(finalString 5(iSOsb
IKMsY5i
namedQuery){ 36kc4=
return getHibernateTemplate QoW(tM
6o[0sM_];
().findByNamedQuery(namedQuery); xE G+%Uk{
} vI
pO/m.3
3t"~F%4-}
publicList findByNamedQuery(finalString query,
nR,Qm=;
<O,'5+zG%
finalObject parameter){ ++Rdv0~
return getHibernateTemplate M&|sR+$^
k8InbX[
().findByNamedQuery(query, parameter); 2|0Je^$|
} ;H7EB`
%K&+~CJE
publicList findByNamedQuery(finalString query, %mK3N2N$
L?3VyBE
finalObject[] parameters){ l]a^"4L4`o
return getHibernateTemplate V9 +xL 1U#
=Q/w% 8G
().findByNamedQuery(query, parameters); W; 3
R;
} Qag|nLoT
;x!,g5q"q
publicList find(finalString query){ E<D+)A
return getHibernateTemplate().find u4Y6B
]Q
)^jQkfL
(query); O tXw/
} [ E$$nNs
!XgQJ7y_Z
publicList find(finalString query, finalObject FSW3'
NDB*BmG
parameter){ SKB@
return getHibernateTemplate().find 8eOl@}bV
(,- 5(fW
(query, parameter); g2[K<
} cOzg/~\1
*fxep08B
public PaginationSupport findPageByCriteria F`YFo)W
lEO?kn.:z
(final DetachedCriteria detachedCriteria){ S2koXg(
return findPageByCriteria p&k0Rx0Q3
BlkSWW/
(detachedCriteria, PaginationSupport.PAGESIZE, 0); L]c 8d
} q6;OS.f
KcIc'G 9
public PaginationSupport findPageByCriteria T5K-gz7A
O]e6i%?
(final DetachedCriteria detachedCriteria, finalint )HJK '@
7^kH8qJ)
startIndex){ RtW4n:c
return findPageByCriteria >[Xm|A#
M?E9N{t8)a
(detachedCriteria, PaginationSupport.PAGESIZE, EsT0"{
Nhjle@J<
startIndex); O"@?U
} c_~XL^B@
2B6^]pSk
public PaginationSupport findPageByCriteria EG F:xl
aj&\CJ
(final DetachedCriteria detachedCriteria, finalint @;||peU
1k!D0f3qb
pageSize, hWe}'L-
finalint startIndex){ y\[L?Rmd
return(PaginationSupport) Nawp t%
$@_YdZ!
getHibernateTemplate().execute(new HibernateCallback(){ l0gH(28K
publicObject doInHibernate 6tOP}X
"AT&!t[J
(Session session)throws HibernateException {
bZxv/\
Criteria criteria = o:Ln._bj
RM)1*l`!E
detachedCriteria.getExecutableCriteria(session);
]a78tTi
int totalCount = Sv.KI{;v$
\z2vV+f
((Integer) criteria.setProjection(Projections.rowCount y' 2<qj
cge-'/8w%
()).uniqueResult()).intValue();
$`^H:Djr
criteria.setProjection
DY$yiOH9
PqTYAN&F
(null); b OW}"
List items = uEBQoP2
YavfjS:2
criteria.setFirstResult(startIndex).setMaxResults ri_P;#lz
8&i;hZm
(pageSize).list(); gs$3)t
PaginationSupport ps = _Mlhumt
`2pO5B50
new PaginationSupport(items, totalCount, pageSize, jeY4yM
FL59
startIndex); RwUW;hU
return ps; Vz%"9`r
} S*;#'j)4+
}, true); ERk kSTp
} J =b*
rU],J!LF
public List findAllByCriteria(final ZQ@3P7T
7TP$
DetachedCriteria detachedCriteria){ #g,H("Qy({
return(List) getHibernateTemplate AzZi{Q ?
pMOD\J:l,
().execute(new HibernateCallback(){ 7^HpVcSM
publicObject doInHibernate rZ pbu>S
X88F>1}
(Session session)throws HibernateException { AlUJ1^o)
Criteria criteria = ] OUD5T
$H4=QVj6
detachedCriteria.getExecutableCriteria(session); 6KVV z/
return criteria.list(); ki#y&{v9Be
} K/DH
/
r
}, true); XnD0eua#
} 5Qb;2!
%?@x]B9Y8E
public int getCountByCriteria(final =1O?jrl~q
AD(xaQ&T
DetachedCriteria detachedCriteria){ e,^pMg~
Integer count = (Integer) }Bd_:#.mw
xOhRTxic
getHibernateTemplate().execute(new HibernateCallback(){ e!6eZ)l
publicObject doInHibernate ubD#I{~J
%@>YNPD`E
(Session session)throws HibernateException { #sL/y
Criteria criteria = 0xv\D0
ohtT
O]\
detachedCriteria.getExecutableCriteria(session); D^$]>-^
return S=4R5igrC
V_jiOT!
criteria.setProjection(Projections.rowCount +5#x6[
!TGr .R
()).uniqueResult(); *}7U`Aa
} t`uc3ta"9
}, true); wtq,`'B
return count.intValue(); }lH;[+u3
} c$/<l5Uw
} {JTmP `&l
>)4.$#H
)4PB<[u
_'&k#Q
2,+d|1(4o
70{RDj6{
用户在web层构造查询条件detachedCriteria,和可选的 @#A!w;bz
L+7*NaPY*
startIndex,调用业务bean的相应findByCriteria方法,返回一个
M'YJ"
I`3d;l;d
PaginationSupport的实例ps。 5|5=Y/
ad9EG#mD#
ps.getItems()得到已分页好的结果集 f:S}h-AL&
ps.getIndexes()得到分页索引的数组 A3j"/eKi2
ps.getTotalCount()得到总结果数 [~t yDLC
ps.getStartIndex()当前分页索引 _$!`VA%
ps.getNextIndex()下一页索引 pVY4q0@
ps.getPreviousIndex()上一页索引 D]jkR} t
gbJG`zC>U
!h?=Wv
==]
YKNb59k
Y4`QK+~fH
s88y{o
2g0K76=Co:
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 I-TlrW=t
,^HS`!s[ E
,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 (N7O+3+G
ve6x/ PD
一下代码重构了。 SijS5irfk
$ND90my
我把原本我的做法也提供出来供大家讨论吧:
|g+!
} +1'{B"I
首先,为了实现分页查询,我封装了一个Page类: sx:Hv1d
java代码: ,2,W^HJ
j|k@MfA
f'i6QMk\&
/*Created on 2005-4-14*/ v O PMgEI
package org.flyware.util.page; !n:uiwh
;|;iCaD a+
/** 1b8c67j[
* @author Joa Jb9F=s+
* ~+=E"9Oo
*/ UUGe"]V^g:
publicclass Page { YlrB@mE0n$
sLZ>v
/** imply if the page has previous page */ 8sH50jeP
privateboolean hasPrePage; B O]=vH
v"/TmiZ
/** imply if the page has next page */ VJ*\pM@no
privateboolean hasNextPage; %/Bvy*X&
0lBat_<8
/** the number of every page */ ldYeX+J
_
privateint everyPage; {!MVc<G.
? -CV
%l
/** the total page number */
9|<Be6
privateint totalPage; y)tYSTJK
s+'XQs^{aj
/** the number of current page */ !:d L~n
privateint currentPage; b#A(*a_gN
Qne0kB5m
/** the begin index of the records by the current IyOpju)?
IKo;9|2U
query */ LfHzT<)|
privateint beginIndex; yZ5x88 >
}f]b't
M}u1qXa
/** The default constructor */ l0. FiO@_Q
public Page(){ v iJJ
e'\2
`On3/gU|
} P,U$ %C!
d-h"JZ9
/** construct the page by everyPage UP]1(S?
* @param everyPage "1K:/n
* */ o(zTNk5d
public Page(int everyPage){ =!<^^6LZ
this.everyPage = everyPage; .$P|^Zx,
} b[yE~EQxr
Hsgy'X%om
/** The whole constructor */ TOrMXcn!/
public Page(boolean hasPrePage, boolean hasNextPage, 0d";Hh:
e6 2y
_;7fraqX
int everyPage, int totalPage, |_, /u_
int currentPage, int beginIndex){ 0 7\02f
this.hasPrePage = hasPrePage; ><K!~pst}
this.hasNextPage = hasNextPage; i%MA"I\9
this.everyPage = everyPage; ` zY!`G
this.totalPage = totalPage; DRp&IP<
this.currentPage = currentPage; F3Ap1-%z
this.beginIndex = beginIndex; OT;cfkf7
} O)1E$#~
Xo8DEr
/** N ocFvF7\
* @return A4
5m)wQ
* Returns the beginIndex. 3p&jLFphL
*/ i5VG2S
publicint getBeginIndex(){ 06jMj26!
return beginIndex; GQ[pG{_+
} p/3BD&6
[Y$V\h=V
/** d/lffNS=
* @param beginIndex R:f7LRF/\
* The beginIndex to set. -%H%m`wD
*/ [IMQIX
publicvoid setBeginIndex(int beginIndex){ :/i~y $t
this.beginIndex = beginIndex; D^|7#b,zcH
} G5;V.#"Z[
LN\[Tmd &
/** ;y OD
* @return y1#O%=g
* Returns the currentPage. }PZ=`w*O
*/ 79wLT\&
publicint getCurrentPage(){ B=dseeG[To
return currentPage; as#J qE
} {+Sq<J_`M
T
.hb#oO
/** 7*;^UqGjz
* @param currentPage C\A49q
* The currentPage to set. ,T{oy:rB
*/ ??(Kwtx{
publicvoid setCurrentPage(int currentPage){ qv uxhz F
this.currentPage = currentPage; &[~[~m|
} `.8UKSH+
V^2-_V]8
/** \K}aQKB/j
* @return M~p=#V1D
* Returns the everyPage. (Q_2ODKo
*/ K$ AB} Fvc
publicint getEveryPage(){ 1`QsW&9=b
return everyPage; Z2bUs!0
} +Vy_9I(4Z
0;<OYbm3<
/** cgN>3cE
* @param everyPage i-.c=M
* The everyPage to set. N~| t!G*9
*/ S=PJhAF
publicvoid setEveryPage(int everyPage){ W&KM/9d
this.everyPage = everyPage; s!de2z
} 8lb-}=
<xqba4O
/** { 8p\Y
* @return > 0T
Za
* Returns the hasNextPage. dhtb?n{
*/ OpQ8\[X+
publicboolean getHasNextPage(){ KuXkI;63J>
return hasNextPage; ,E9d\+j
} anC+r(jjg9
eO[c l B
/** o|rzN\WJn
* @param hasNextPage !M^\f
N1
* The hasNextPage to set. F~R7~ZE
*/ ^mf jn-=3
publicvoid setHasNextPage(boolean hasNextPage){ gl
"_:atW
this.hasNextPage = hasNextPage; " '[hr$h3
} A?,A(-0C
$:;%bjSI
/** l[*sHi
* @return rN#\AN
* Returns the hasPrePage. no|Gq>Xp
*/ TY6
rwU
publicboolean getHasPrePage(){ +NR n0
z(
return hasPrePage; * <q4S(l
} ]|
WA#8_|
]EN&S Wh
/** $20s]ywS
* @param hasPrePage ~-<:+9m
* The hasPrePage to set. EY$?^iS
*/ KTv4< c]
publicvoid setHasPrePage(boolean hasPrePage){ s#P:6]Ar
this.hasPrePage = hasPrePage; sUciFAb
} U|?,N0%Z1
kFwxK"n@C
/** 9|3o<
* @return Returns the totalPage. Z
Xb}R^O-
* P^zy; Qs7
*/ A{(T'/~"
publicint getTotalPage(){ 41}/w3Z4
return totalPage; DxfMqH[vs
} ;"@ :}_t
!FP"M+
/** De]^&qw(
* @param totalPage Bc[6*Y,%T
* The totalPage to set. W>$BF[x!{
*/ [pR)@$"k'
publicvoid setTotalPage(int totalPage){ "teyi"U+
this.totalPage = totalPage; 5Eal1Qu
} }p*?1N
<4f,G]UH_
} h.^o)T
h>W@U9
F`srE6H
EneAX&SG
MA6P"?
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 9U'[88
,LZ(^u
个PageUtil,负责对Page对象进行构造: 5~U:@Tp
java代码: ~p.%.b;~t
\JU{xQMB
bKUyBk,\#
/*Created on 2005-4-14*/ J7n5Ps\M
package org.flyware.util.page; w_3xKnMT\
Mz\yPT;Y
import org.apache.commons.logging.Log; PG"@A
import org.apache.commons.logging.LogFactory; =ybGb7?
zX~}]?|9
/** )S Q('vwg
* @author Joa H%C\Uz"o
* 4>_d3_1sn
*/ Qi:j)uDW
publicclass PageUtil { ~p^7X2% !
+6376$dC
privatestaticfinal Log logger = LogFactory.getLog XHQh4W3
ppFYc\&=
(PageUtil.class); n ,1tD
6(.H3bu
/** \xeVDKJH+n
* Use the origin page to create a new page k/bque
* @param page 6w!e?B2/%
* @param totalRecords !-RwB@\
* @return !7c'<[+Hm
*/ [TEcg^
publicstatic Page createPage(Page page, int 0I^Eo|
8}z3CuM
totalRecords){ 4 l1 i>_R
return createPage(page.getEveryPage(), @G(xaU'u
Y}/c
N\
page.getCurrentPage(), totalRecords); gVA; `<
} =)*JbwQ
.+vd6Uc5a
/** XNlhu^jh
* the basic page utils not including exception %A2`&:ip
x<
S\D&
handler gn`zy9PU
* @param everyPage z{M8Yf |
* @param currentPage B@-"1m~la?
* @param totalRecords !;+U_j'Pg
* @return page (H1lqlVWV#
*/ sX5sL
publicstatic Page createPage(int everyPage, int IXJ6PpQLv
8nsZ+,@+[
currentPage, int totalRecords){ phS>T
everyPage = getEveryPage(everyPage); BkV(81"C
currentPage = getCurrentPage(currentPage); jN {Zw*
int beginIndex = getBeginIndex(everyPage, 0d`5Gy_ D%
gLx/w\l6
currentPage); !EM#m@kZ{
int totalPage = getTotalPage(everyPage, `*d{PJTv
K%PxA#P}
totalRecords); #s{aulx
boolean hasNextPage = hasNextPage(currentPage, 3G.r-
avy=0Jmj
totalPage); /Zx8nx'{V
boolean hasPrePage = hasPrePage(currentPage); 1ys( v
)Oe`s(O@[I
returnnew Page(hasPrePage, hasNextPage, N33AcV!*8
everyPage, totalPage, 6? !I
currentPage, .HCaXFW
R=Ymo.zs6
beginIndex); 5v3RVaqZ
} O8[k_0@
6y9C@5p}B
privatestaticint getEveryPage(int everyPage){ ,{+6$h3
return everyPage == 0 ? 10 : everyPage; ?rQc<;b
} Q)T+r~#2B
/yp/9r@T0
privatestaticint getCurrentPage(int currentPage){ 9#fp_G;=
return currentPage == 0 ? 1 : currentPage; &M=3{[
} `[bJYZBc2
T g{UK
privatestaticint getBeginIndex(int everyPage, int cyHU\!Z*Zq
X\mz+al>[
currentPage){ yXrd2?Rq@
return(currentPage - 1) * everyPage; f,JX"
} on_H6Y@B52
3t*# !^$
privatestaticint getTotalPage(int everyPage, int *:[b'D!A
(:l(_-O
totalRecords){ 5pmQp}}R
int totalPage = 0; 7O9n!aJ
vs\|rLa
if(totalRecords % everyPage == 0) jOv~!7T
totalPage = totalRecords / everyPage; I8Kb{[?q
else -tMA
totalPage = totalRecords / everyPage + 1 ; b@!:=_Mr
fzyzuS$
return totalPage; EU9[F b]
} )6 k1 P
3u4:l
privatestaticboolean hasPrePage(int currentPage){ V pH|R
return currentPage == 1 ? false : true; *k4+ioFnKE
} L W?&a3e
{?y<%@
privatestaticboolean hasNextPage(int currentPage, )gjGG8Ee
4gya]
int totalPage){ pkW5D
return currentPage == totalPage || totalPage == 8UYJye8
j)BQMtt&U
0 ? false : true; 3AvcJ1
} fRFYJFc n
"5h_8k~sQ
@ce3%`c_
} CZ2iJy
oAaf)?8
^9s"FdB]24
~Zu}M>-^c,
;&q]X]bJ
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。 Ym`1<2mq\
Qj:{p5H'
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 .X^43
q
=nw0# '
做法如下: Bqp&2zg)@
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 w0X$rl1
>R#9\/s
的信息,和一个结果集List: Stt* 1gT
java代码: MorW\7-}
38"cbHE3
n{3|E3
/*Created on 2005-6-13*/ L*v93;|s
package com.adt.bo; 9[Y*k^.!
O[L\T
import java.util.List; #]igB9Cf)w
Xa)7`bp<
import org.flyware.util.page.Page; {)@ j77P
T*8_FR <
/** J(^
>?d'
* @author Joa 69rwX"^
*/ F46O!xb%
publicclass Result { \DaLHC~
{vjqy&?y
private Page page; \3M1.Q4$Gr
D?%e"*>
private List content; M{G$Pk8[
6z PV'~q
/** (%.</|u
* The default constructor We|-5
*/ [1mIdwS
public Result(){ bIq-1
Y(
super(); 4sI3(z)9H
} x)d2G6x
|KTpK(6p
/** nwhm[AaNs
* The constructor using fields WVinP(#nfM
* B
JU*`Tx
* @param page 9Y\F53p&j
* @param content aam1tm#Q
*/ -}NAb^d
public Result(Page page, List content){ [O [FCn
this.page = page; '8L(f w{k
this.content = content; !\3}R25
} Qf"6PJ
s!NisF
/** `I@)<d
* @return Returns the content. {rs6"X^
*/ X4XFu
publicList getContent(){ 2YaTT& J
return content; t&8<k+m
} G[vUOEU~O
a
pKa4nI
/** g<0w/n!jmC
* @return Returns the page. Ja^7$WY
*/ !'Gb$l!
public Page getPage(){ ZWov_
return page; ^Kb9@lz/
} _T_PX$B
)H.ubM1
/** EUJ1RhajF
* @param content kbD*=d}3{
* The content to set. &Jrq5Q C
*/ ,>:XE@xcp
public void setContent(List content){ |dW2dQ
this.content = content; buc,M@>
} F]hx
Z#srQD3].(
/** ^
yY{o/6
* @param page S83]O!w0
* The page to set. *;>V2!N=U
*/ nomu$|I
publicvoid setPage(Page page){ InAU\! ew
this.page = page; fmatc#G
} WT;.>F
} u Eu6f
n$nne6|O
TJeou#=/
H9.oVF^~
aE%eJ)+K
2. 编写业务逻辑接口,并实现它(UserManager, _G_ &Me0
kyp U&F
UserManagerImpl) tn(f rccy
java代码: i!s~kk
f0:EQYYZ
v=dKcruR:
/*Created on 2005-7-15*/ %V@R k.<
package com.adt.service; L#83f]vG
/h{go]&Nb
import net.sf.hibernate.HibernateException; *>?):-9"6N
;LwFbkOuU
import org.flyware.util.page.Page; \VoB=Ac&
cq+nWHqF{J
import com.adt.bo.Result; h
v;n[
aNuZ/9O
/** D?^`(X P
* @author Joa #
|[`1
*/ U[K0{PbY
publicinterface UserManager { 'iMHAP;N
p,M3#^ q
public Result listUser(Page page)throws 6,CU)-98G
qk"oFP6
HibernateException; >cvE_g"?C
f\U? :83
} I,?Fqg'sq
9n06n$F
P wt ?9I
<k!mdj)
8=ukS_?Vy
java代码: +?4*,8Tmmz
B}l}Aq8
zLJ:U`uh\
/*Created on 2005-7-15*/ !#cKF6%
package com.adt.service.impl; (ffOu#RQ3
muqfSF
import java.util.List; o O{|C&A
u&l>cJ'
import net.sf.hibernate.HibernateException; es*_Oo1
,6cbD
import org.flyware.util.page.Page; /ze_{{o
import org.flyware.util.page.PageUtil; 5JXzfc9rL
;%b <uV
import com.adt.bo.Result; c (_oK ?
import com.adt.dao.UserDAO; gMoyy
import com.adt.exception.ObjectNotFoundException; q;Ar&VrlNq
import com.adt.service.UserManager; E9 80yXJR
s%S_K
/** h0Sy']3m
* @author Joa rH#c:BwSm
*/ 3;-@<9
publicclass UserManagerImpl implements UserManager { h[[/p {z
s[{:>~{iq
private UserDAO userDAO; vo}_%5v8
)N%1%bg^-
/** 8h@)9Q]d\
* @param userDAO The userDAO to set. 0Tn|Q9R
*/ ?Uy*6YS
publicvoid setUserDAO(UserDAO userDAO){ hVt+%tmNy
this.userDAO = userDAO; aQym=
6%e
} >X\s[d&(
QB.*R? A
/* (non-Javadoc) X{9JSq
* @see com.adt.service.UserManager#listUser k_|v)\4B
"k_n+cH%
(org.flyware.util.page.Page) ixI5Xd<
*/ _sf0{/< )
public Result listUser(Page page)throws 6{Cu~G{]N
J:TI>*tn
HibernateException, ObjectNotFoundException { GqK&'c
int totalRecords = userDAO.getUserCount(); G,mH!lSm,
if(totalRecords == 0) ;5JIY7t
throw new ObjectNotFoundException }TAGr 0
)2^/?jK
("userNotExist"); 8ZDqqz^C0
page = PageUtil.createPage(page, totalRecords); 0u&?Zy9&
List users = userDAO.getUserByPage(page); uYFcq
returnnew Result(page, users); T0]%(F/8
} 61Iy{-/ZV
>I8hFtAM
} 65`'Upu
mSfkyw.
]9yA0,z/
lo]B5_en
~"<VUJ=Ly:
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 p?`|CE@h7
+<9q]V
询,接下来编写UserDAO的代码: $=QGua V
3. UserDAO 和 UserDAOImpl: lj SR?:\
java代码: uI:3$
|@Idf`N$
#3:'lGBIK
/*Created on 2005-7-15*/ 39a]B`y
package com.adt.dao; ptc H>wM!
Rp%\`'+Xz
import java.util.List; C4SD
as\K(c9
import org.flyware.util.page.Page; J ]l@ r
51;%\@=
import net.sf.hibernate.HibernateException; [k&s!Qp
id[>!fQ=Y
/** PuoJw~^h
* @author Joa ZX5A%`<M
*/ [,szx1
publicinterface UserDAO extends BaseDAO { t[yD8h
jv#" vQ9A]
publicList getUserByName(String name)throws aXid;v,
^N}~U5
HibernateException; <+1w'-
ZD] '$
publicint getUserCount()throws HibernateException; q$2taG}
*~oDP@[S
publicList getUserByPage(Page page)throws -Fw4;&>
bHo?Rw!.
HibernateException; RKJWLofX&
&= yqWW?
} eiSO7cGy
d8q$&(]<
Ckl]fy@D}
4.kkxQR7r
Y;5^w=V
java代码: <x;[ H%
5J2p^$s
\iLd6Qo_aq
/*Created on 2005-7-15*/ `kT$Gx4x
package com.adt.dao.impl; _itN.^
AJ1$$c
import java.util.List; z'}t@R#H
:IKp7BS
import org.flyware.util.page.Page; P}u<NPy3Q
;\&bvGj8V
import net.sf.hibernate.HibernateException; f'yd{ihFp
import net.sf.hibernate.Query; l aL4ez
:Y?08/V
import com.adt.dao.UserDAO; 1bAp{u&
*oJ>4S
/** 5lA 8e
* @author Joa zs^\zCb8
*/ 8lb
`
public class UserDAOImpl extends BaseDAOHibernateImpl ::b;4QL
E2/U']R
implements UserDAO { $gtT5{"PN(
KUn5S&eB
/* (non-Javadoc) "dU#j,B2
* @see com.adt.dao.UserDAO#getUserByName 8o5^H>
xMGd'l?
(java.lang.String) l|QFNW[i
*/ z+B
publicList getUserByName(String name)throws W p*
v Vv
^?VT y5yp
HibernateException { 0`Qs=R`OM
String querySentence = "FROM user in class +fR`@HI
Xwq2;Bq
com.adt.po.User WHERE user.name=:name"; Q-%=ZW Z
Query query = getSession().createQuery E|}Nj}(*
k
<Sa<
(querySentence); :[?o7%"
query.setParameter("name", name); 'GO..m"G
return query.list(); ,O`*AzjS5Q
} QO^X7A"?X
rca"q[,
/* (non-Javadoc) mZ&Mj.0+~
* @see com.adt.dao.UserDAO#getUserCount() U"G+su->e
*/ t`3T_t Y
publicint getUserCount()throws HibernateException { qO'5*d;!d
int count = 0; ~$obcW1
String querySentence = "SELECT count(*) FROM -Af`AX
] ]-0RJ=S?
user in class com.adt.po.User"; _C#()#
Query query = getSession().createQuery H~K2`Cr)4
MX_a]$\:n
(querySentence); l;FgX+)
count = ((Integer)query.iterate().next R20GjWy=
KD*4n'm!>
()).intValue(); bg. KkJMrR
return count; {v'Fg
} /[T8/7;_l
TBp5xz`
/* (non-Javadoc) #gT^hl5/
* @see com.adt.dao.UserDAO#getUserByPage %),O9*[9
R63d
`W
(org.flyware.util.page.Page) nvs7s0@Fqe
*/ a5S/
O;ry
publicList getUserByPage(Page page)throws B{KD ]
fYPU'"hzG
HibernateException { 2|o$eq3t
String querySentence = "FROM user in class vw
2@}#\:
6%y: hLT
com.adt.po.User"; q &o=4
Query query = getSession().createQuery k/Ro74f=
\kO_"{7n
(querySentence); #ms98pw%5
query.setFirstResult(page.getBeginIndex()) nxRrmR}F
.setMaxResults(page.getEveryPage()); (R,n`x2^
return query.list(); mMWNUkDq
} ) O^08]Y g
o~>go_Y
} \F3t&:
k3kqgR*
aE$p;I
^}L$[P
5ZxBmQ
至此,一个完整的分页程序完成。前台的只需要调用 jO.E#Ei}~
Q;M\P/f
userManager.listUser(page)即可得到一个Page对象和结果集对象 m"}G-#
FvP1;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 Vs{sB*:
Or|LyQU
webwork,甚至可以直接在配置文件中指定。 y70gNPuTOD
|Ay#0uQ5Y
下面给出一个webwork调用示例: }y/t~f+
java代码: GTvb^+6
Z&!$G'X
v83 6nxL M
/*Created on 2005-6-17*/ 0w]?yqnE
package com.adt.action.user; B!anY}/U
n|6yz[N
import java.util.List; jT0fF
D1k]
import org.apache.commons.logging.Log; XrF9*>ti?
import org.apache.commons.logging.LogFactory; \/Y<.#?_
import org.flyware.util.page.Page; ,{at?y*
jd*H$BU^
import com.adt.bo.Result; i[n1}E.@
import com.adt.service.UserService; S3fBZIPp
import com.opensymphony.xwork.Action; /#5ZP\e
WI3!?>d
/** )]R8
$S
* @author Joa Y8(yOVy9
*/ 39CPFgi<l*
publicclass ListUser implementsAction{ nU)f]4q{Ec
EK^2 2vi$
privatestaticfinal Log logger = LogFactory.getLog "k/@tX1:R
Hua8/:![+
(ListUser.class); h,g~J-x`|
ZAwl,N){
private UserService userService; w@We,FUJN
j!dklQh0
private Page page; \ZH=$c*W
8%Lg)hvl
privateList users; 7Cjrh"al"
J)]W[Nk
/* @<L.#gtP
* (non-Javadoc) CqV
\:50g
* P/5r(l5
* @see com.opensymphony.xwork.Action#execute() ^D)C|T
*/ %94"e7Hy
publicString execute()throwsException{ LTHS&3%2
Result result = userService.listUser(page); S;~_9i]upe
page = result.getPage(); F(r&:3!97
users = result.getContent(); V96BtVsB
return SUCCESS; 9Wn0YIc
} VM`."un]
f63q
/** KtE`L4tW6
* @return Returns the page. /~:ztv\$M"
*/ 3@PVUJ0B|
public Page getPage(){ Kt(p|
return page; q$P"o].EK
} _U %B1s3y
_DQdo
/** tp"\
* @return Returns the users. "$_ypgRrSR
*/ 1mqFnVkf&+
publicList getUsers(){ b,wO^07-3^
return users; [B
Al
} u CXd%
CzE
:>=,sLfJ
/** gTT-7
* @param page 53A=Ogk8S
* The page to set. (,>`\\
*/ bc-"If Z&
publicvoid setPage(Page page){ _"n4SXhq
this.page = page; |Cm}%sgR\0
} (@zn[Nq
TocqoYX{{
/** k6XO-a f
* @param users a%kj)ah
* The users to set. !jm
a --
*/ G>b1No3%k
publicvoid setUsers(List users){ 8}&cE#@
this.users = users; eF9LZ"-s
} O`eNuQSv
v-o/zud]]
/** m(Oup=\%b}
* @param userService #AHIlUH"m
* The userService to set. +_<#8v
*/ U1Oq"Ij~
publicvoid setUserService(UserService userService){ "F^EfpcJ{9
this.userService = userService; f'
eKX7R
} Oe?nX>
} Cfi5r|S
j>U.(K
pP .
*UTk. :G5
xg8<b
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, Z7 @#0;g{
{VFpfo
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 #Xc~3rg9
}v:h EMO
么只需要: uo0(W3Q *
java代码: r=vE0;7
2b<0g@~X
z}5XLa^
<?xml version="1.0"?> \%K6T)9
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 9X-DR
eK`tFs,u
1.0//EN" "http://www.opensymphony.com/xwork/xwork- g$+3IVq&
Q{%ow:;s*
1.0.dtd"> lm+wjhkN
.p&M@h
w
<xwork> /w|YNDA]j
yfU1;MI
<package name="user" extends="webwork- |1neCP@ng
E^rN)
interceptors"> zw0p}
ka (xU#;
<!-- The default interceptor stack name 3cnsJV]
Xd4~N:
--> D=8=wT2<
<default-interceptor-ref @8 pRIS"V
N7NK1<vw2
name="myDefaultWebStack"/>
zd}"8
(Lc%G~{
<action name="listUser" i}Y:o}
_C##U; e!
class="com.adt.action.user.ListUser"> =Vi+wH{xM
<param @+xQj.jNC
H;v*/~zl
name="page.everyPage">10</param> n9#@
e}r
<result wBr0s*1I
P\Ka'i
name="success">/user/user_list.jsp</result> Mqna0"IYx*
</action> 'rSM6j
J[^-k!9M
</package> vnKUD|
(h
E^<jNR
</xwork> v"^G9u
[ [Z*n/tr
$+Xohtt
?&[`=ZVn
M; V2O;
m49)c K?
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 7{p,<Uz<"U
ec{pWzAe
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。 5y.kOe4vH
ZN.
#g_
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 (u~@@d"
NpSS/rd $
V
]Z{0
gI[xOK#
q$\KE4v"
我写的一个用于分页的类,用了泛型了,hoho 7r:!HmRl
Zb@PwH4
java代码: Mq-;sPsFP
-c Mqq$
Obbjl@]
package com.intokr.util; 1;>J9
sVGyHA
import java.util.List; d^w6_
"wdC/
/** 6<gh:vj
* 用于分页的类<br> zh7NXTzyf
* 可以用于传递查询的结果也可以用于传送查询的参数<br> Ty7xjIs
* ^W;\faG
* @version 0.01 _/hWzj=q
* @author cheng W<\KRF$S;
*/ -_B*~M/vV`
public class Paginator<E> { &kh-2#E
privateint count = 0; // 总记录数 <"6}C)G
privateint p = 1; // 页编号 caS5>wk`R
privateint num = 20; // 每页的记录数 6m?}oMz
privateList<E> results = null; // 结果 &S/KR$^ %
dtJ?J<m}
/** {"-uaH>,
* 结果总数 3b~k)t4R
*/ X"*pt5B6`
publicint getCount(){ y%f'7YZ4
return count; T$!.
:v
} d7A vx
2Lm.;l4YO
publicvoid setCount(int count){ ca5Ir<mL
this.count = count; L2+~I<|>
} }qxwNmx
6V W&An[6r
/** +hGr2%*0f
* 本结果所在的页码,从1开始 ;~F&b:CyG
* kyMWO*>|
* @return Returns the pageNo. \s<L2uRj
*/ T=%,^
publicint getP(){ 4 1q|R[js!
return p; Y$ZZ0m
} 4~4D1
4+Wti!s
/** -uX): h!
* if(p<=0) p=1 }Dp/K4
* @!`x^Tzz
* @param p M]
7#
*/ /GRkQ",
publicvoid setP(int p){ WTbq)D(&[_
if(p <= 0) E&9BeU
a#
p = 1; HW"@~-\
this.p = p; ,#m:U5#h
} {W,&jC
kIrb;bZ+l
/** h8'`g 0
* 每页记录数量 bL-+
*/ dD ?ZF6
publicint getNum(){ NSI$uS6
return num; H[S[ y
} n
'gU
ir!/{IQx
/** p?PK8GL
* if(num<1) num=1 vnc-W3N
*/ b1\.hi
publicvoid setNum(int num){ c&X2k\
if(num < 1) mQUI9
num = 1; Xs}.7
this.num = num; grrM[Y7#~b
} UU'0WIbY6
a]\l:r
/** ^ZP
$(a4
* 获得总页数 pr-=<[ d
*/ _Fkz^B*
publicint getPageNum(){ %W`
}
return(count - 1) / num + 1; e*)*__$O
} -aPRLHR
|kGj}v3
/** z[|2od
* 获得本页的开始编号,为 (p-1)*num+1 iC2``[m"
*/ -?z#
publicint getStart(){ )xm[m vt
return(p - 1) * num + 1; [0MNq]gxf
} JCO+_d#x
ur\<NApT;
/** m55|&Ux|
* @return Returns the results. 6--t6>5
*/ Opavno%&
publicList<E> getResults(){ Nux
return results; Gn&=<q:H
} y90wLU9f
tzJ7wXRr
public void setResults(List<E> results){ aGBUFCCa
this.results = results; u43W.4H13
} ]}4JT
n,D&pl9f
public String toString(){ g^I?u$&E
StringBuilder buff = new StringBuilder hU'h78bt(
?mwa6]
(); Y#[xX2z9
buff.append("{"); m941 Y
buff.append("count:").append(count); vB<9M-sa0
buff.append(",p:").append(p); {:]u 6l
buff.append(",nump:").append(num); BD,J4xH;
buff.append(",results:").append 9$f%
+R"Y~
m{F
(results); $:|?z_@
buff.append("}"); o4U0kiI@
return buff.toString(); 8B!MgNKV
} C&HN#Q_
?`T Q'#P`
} L8,/
0@yw#.j
Q@ua
G,6