Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 2LS03 27
4D(5WJ&
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 I6?n>
H4DM,.04
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 %Wy$m?gD
Ce 3{KGBw
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 B3 f Kb#T
A2 'W
。 +>BLox6
7,0^|P
分页支持类: ;tK%Q~To
[JI>e;l
C:
java代码: rN0G|
z|,YO6(L
R+vago:
package com.javaeye.common.util; ]o}g~Xn
hgt@Mb
import java.util.List; kY d'6+m
Q+L;k
R
publicclass PaginationSupport { XL9smFq
B",5"'id
publicfinalstaticint PAGESIZE = 30; ko-| hBNv
~<[$.8*
privateint pageSize = PAGESIZE; M*XAyo4fI
S0-f_,(
privateList items; >uHU3<2&
}J=>nL'B
privateint totalCount; 4^4<Le-G
J+hiz3N
privateint[] indexes = newint[0]; GWb=X cx
S$O+p&!X
privateint startIndex = 0; !4"(>Rnw
Ltv!;^Q5
public PaginationSupport(List items, int ~SKV%
c~1+5&
totalCount){ "cJ))v-'
setPageSize(PAGESIZE); Uk@du7P1k
setTotalCount(totalCount); Ag[Zs%X
setItems(items); EI+RF{IKh
setStartIndex(0);
o[$~
} 0v7#vZ
8PKUg
"p
public PaginationSupport(List items, int S F:>dneB
b'x26wT?
totalCount, int startIndex){ Ez()W,6]g
setPageSize(PAGESIZE); :V,agAMn
setTotalCount(totalCount); /\7E&n:)2
setItems(items); 4gR;,%E\TO
setStartIndex(startIndex); xxnvz
} q4y P\B
pCacm@(hG
public PaginationSupport(List items, int +(Q$GO%
{C>E*qp}f
totalCount, int pageSize, int startIndex){ w.7pD
setPageSize(pageSize); ?nf !sJ'm
setTotalCount(totalCount); -hd@<+;E
setItems(items); T`ofj7$:
setStartIndex(startIndex); \&!qw[;O
} ey/{Z<D
LyR bD$m
publicList getItems(){ :P'M|U
return items; K*!qt(D&
} +,g3Xqs}X
*F:)S"3_~e
publicvoid setItems(List items){ mJU1n
this.items = items; |Eyn0\OA
} ,1K`w:uhS
=)c^ik%F&
publicint getPageSize(){ c1Rn1M,2k
return pageSize; 6 2*p*t
} te[#FF3{
?zk#}Ex1
publicvoid setPageSize(int pageSize){ 3<
'bi}{
this.pageSize = pageSize; 1
ORA6
} GQH15_
5+DId7d'n
publicint getTotalCount(){ +0l-zd\
return totalCount; N^Hj%5
} ]t"X~
xqQLri}
publicvoid setTotalCount(int totalCount){ ?hmuAgOtbh
if(totalCount > 0){ ;Yve m
this.totalCount = totalCount; ~ K/_51O'
int count = totalCount / ?/}N
|Vo{ {)
pageSize; /lS5B6NU
if(totalCount % pageSize > 0) =91wC
count++;
p]eVby"
indexes = newint[count]; PcQ\o>0")
for(int i = 0; i < count; i++){ Y|!m
indexes = pageSize * J kxsua
dQs>=(|t
i; 6Z l#$>P
} tMiy`CPh
}else{ ipe8U1Sc
this.totalCount = 0; LC,6hpmh
} 6r.#/' "
} JJHO E{%
Q ~f mVWq
publicint[] getIndexes(){ (M 2hK[
return indexes; =D&XE*qkZ
} /!'Png0!
z2lT4SAv+
publicvoid setIndexes(int[] indexes){ 9|WV28PK:
this.indexes = indexes; /|p\l"
} "Q`Le{
,4j^lgJ
publicint getStartIndex(){ 9~J#> C0}
return startIndex; (?xR<]~g*
} `\r<3?
jf.WmiDC
publicvoid setStartIndex(int startIndex){ ti^=aB
if(totalCount <= 0) SyI\ulmL
this.startIndex = 0; VXnWY8\
elseif(startIndex >= totalCount) 9vP#/ -g
this.startIndex = indexes kni{1Gr
QM'|k6
[indexes.length - 1]; Pm]lr|Q{I
elseif(startIndex < 0) h0
Xc=nj
this.startIndex = 0; p}Um+I=1
else{ PpLiH9}
this.startIndex = indexes ,A5}HRW%
]XASim:A
[startIndex / pageSize]; +Ks 3
} h[;DRD!Z
} PXG@]$~3
TBIr^n>Z<k
publicint getNextIndex(){ 5,pEJ>dDD3
int nextIndex = getStartIndex() + 'ka}x~EF
&;bey4_J
pageSize; !"ir}Y%
if(nextIndex >= totalCount) CTe!jMZ=
return getStartIndex(); azzG
else }G "EdhSl
return nextIndex; 2tg 07
} (f2r4Io|}
eE_$ ADEf
publicint getPreviousIndex(){ 9{}"tk5$h
int previousIndex = getStartIndex() - yFn~rv|&G
5|7<ZL3
pageSize; DS9-i2
if(previousIndex < 0) +4p=a [
return0; @}
+k]c25
else HRyhq;C
return previousIndex; 3kT?Y7<fv
} III:jhh
@r^s70{}
} ]9~Il#
;Ea8>
7|yEf
'BUfdb8d
抽象业务类 ^G 'n
z
java代码: m?gGFxo
,@fx[5{
0_AIKJrL
/** vL;>A]oM2
* Created on 2005-7-12 N]14~r=
*/ c^cr_i
package com.javaeye.common.business; l8J2Xd @
|#{ i7>2U
import java.io.Serializable; DAg*
import java.util.List; K2\)9
=.OzpV)=V
import org.hibernate.Criteria; y>:U&P^
import org.hibernate.HibernateException; +6}CNC9Mp
import org.hibernate.Session; E^gN]Z"O
import org.hibernate.criterion.DetachedCriteria; \3]O?'
import org.hibernate.criterion.Projections; ji\&?%(B
import y(/5l
(74y2U6
org.springframework.orm.hibernate3.HibernateCallback; B'mUDW8\D
import W'=}2Y$]u
vC^{,?@
org.springframework.orm.hibernate3.support.HibernateDaoS W8Wjq
DQ
Q1{9>NI
upport; WMW=RgiW\
b#"&]s-
import com.javaeye.common.util.PaginationSupport; ,j9? 9Z7R
Q, "8Ty
public abstract class AbstractManager extends X&| R\v=}
'/OQ[f=K
HibernateDaoSupport { _yX.Apv]
^16zZ*
privateboolean cacheQueries = false; ^ fyue~9u
z;?j+ZsdH
privateString queryCacheRegion; 3IjsV5a
+V9xKhR;x
publicvoid setCacheQueries(boolean -j2y#aP
Jf0i$
cacheQueries){ l]#=I7 6
this.cacheQueries = cacheQueries; ?Bl/bY$*h
} fBh/$
@HSK[[?
publicvoid setQueryCacheRegion(String h{H*k#>
~R~.D
queryCacheRegion){ LXsZk|IhM
this.queryCacheRegion = ?E(X>tH
)''V}Zn.X
queryCacheRegion; WRA L/
} 5W&L cBB
IbJl/N%o
publicvoid save(finalObject entity){ lUA-ug! ^
getHibernateTemplate().save(entity); (fr=N5
} #B6f{D[pI
](8F]J ,
publicvoid persist(finalObject entity){ %W2U$I5
getHibernateTemplate().save(entity); /#&jF:h
} &l!T2PX!
XJKns
publicvoid update(finalObject entity){ m[iQ7/
getHibernateTemplate().update(entity); rly%+B `/
} PB.'huu
?G!~&
publicvoid delete(finalObject entity){ ;+|Z5+7!6
getHibernateTemplate().delete(entity); Rm79mh9
} JR
xY#k
*h=>*t?I2
publicObject load(finalClass entity, -*~
@?
'6e4rn{
finalSerializable id){ H?M:<q0|G
return getHibernateTemplate().load *5*#Z~dut8
nCp_RJu
(entity, id); afna7TlS
} k9<UDg_ Y
vu91"
4Fa
publicObject get(finalClass entity, sQ^t8Y9
NWPT89@ l
finalSerializable id){ GG<0k\RN
return getHibernateTemplate().get frDMFEXXP
cQ1Axs TO
(entity, id);
:TR:tf
} #Ha"rr46p
|r,})o>
publicList findAll(finalClass entity){ x3#:C=
return getHibernateTemplate().find("from ~Dz:n]Vk/
s]0 J'UN
" + entity.getName()); }$L1A
} p8@8b "
GYiL}itD=3
publicList findByNamedQuery(finalString ]B3+&g
frW\!r{LT
namedQuery){ XTk
:lzFH
return getHibernateTemplate +!px+*)bW
&"gX
7cK8
().findByNamedQuery(namedQuery); ~TXu20c
} zTfjuI|R
\lQI;b;$
publicList findByNamedQuery(finalString query, 3)LS#=
|6DJ5VFzD
finalObject parameter){ z;2& d<h
return getHibernateTemplate m9MYd
qC"`i}7
().findByNamedQuery(query, parameter); =uNc\a (
} 9a`~ K L
y=f.;
publicList findByNamedQuery(finalString query, O-)[!8r
T ,!CDm$=
finalObject[] parameters){ EA1&D^nT
return getHibernateTemplate 9+@z:j
%saP>]o
().findByNamedQuery(query, parameters); 1y6<gptx
} <pa-C2Ky
Bhx.q,X
publicList find(finalString query){ !\d~9H%`B
return getHibernateTemplate().find (jhi<eV
)m8Gbkj<
(query); +zk5du^gZ
} I3r")}P
4gev^/^^
publicList find(finalString query, finalObject pM+9K:^B
yih|6sd$F
parameter){ \),f?f-m
return getHibernateTemplate().find Opg_-Bf
y4|<+9<7
(query, parameter); L'`Au/%S}
} 8%YyxoCH
}Rh%bf7,
public PaginationSupport findPageByCriteria +aM[!pW(e
mOHOv61
(final DetachedCriteria detachedCriteria){ %g5#q64
return findPageByCriteria ;/wH/!b
*,:2O&P
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 1BW 9,Xr
} D4y!l~_,%M
"K9[P:nw
public PaginationSupport findPageByCriteria J1cz
D |(
-EFdP] XO
(final DetachedCriteria detachedCriteria, finalint SB('Nqih
I9aiAD0s
startIndex){ 0g=vMLi
return findPageByCriteria ._A4:
yX{7<\x
(detachedCriteria, PaginationSupport.PAGESIZE, J@<f*
N TDmOS\,
startIndex); p$x>I3C(\
} T95FoA
we!w5./Xm
public PaginationSupport findPageByCriteria \}k R'l
AX6:*aZB
(final DetachedCriteria detachedCriteria, finalint eY?OUS
Tmu2G/yi
pageSize, X6$Cd]MN
finalint startIndex){ >d"\
return(PaginationSupport) KQ6][2-
HN/YuP03[
getHibernateTemplate().execute(new HibernateCallback(){ ThW9=kzQW
publicObject doInHibernate nSQ]qH&4d
}QQl.'
(Session session)throws HibernateException { Xg1TX_3Ml
Criteria criteria = l*w' O
`
-SC,qHw
detachedCriteria.getExecutableCriteria(session); 1|>vk+;1h
int totalCount = K%/\XnCY
<jYyA]Zy5
((Integer) criteria.setProjection(Projections.rowCount [)8O\/:
+ `'wY?
()).uniqueResult()).intValue(); 9{S$%D
criteria.setProjection R8!~>$#C6)
=^*EM<WG)
(null); ']c;$wP
List items = -AVT+RE9z
z52F-<
criteria.setFirstResult(startIndex).setMaxResults yHs9J1Sf
+"WNG
(pageSize).list(); Q;=4']hYU
PaginationSupport ps = /FW$)w2{j
^c.pvC"4j
new PaginationSupport(items, totalCount, pageSize, ;Z"Iv
}7{(o-
startIndex); |t3}>+"?z
return ps; 2Z<S^9O9
} a5pM ~.]
}, true); A>S7Ap4z>
} iny/K/5bf
Y4,p_6aKJ]
public List findAllByCriteria(final U Lq`!1{
NL-PQ%lUA
DetachedCriteria detachedCriteria){ uP8 cW([
return(List) getHibernateTemplate sH1ucZ>9Y
}lJ|nl`c
().execute(new HibernateCallback(){ g3%x"SlIU
publicObject doInHibernate D( TfW
p`U#
(Session session)throws HibernateException { &n83>Q
Criteria criteria = QP!;Gwqr
9T`YHA'g
detachedCriteria.getExecutableCriteria(session); j 7O!uUQQ
return criteria.list(); tN.BI1nB
} VRY@}>W'
}, true); [6.<#_~{
} k!+v*+R+V
X
)
=-a
public int getCountByCriteria(final =R9`to|
c1*^
\
DetachedCriteria detachedCriteria){ Z.aeE*Hs$
Integer count = (Integer) $mf6!p4
PqyR,Bcx0
getHibernateTemplate().execute(new HibernateCallback(){ Xfg?\j/
publicObject doInHibernate +8|Xj!!*}
V!+<
(Session session)throws HibernateException { i#4E*B_-
Criteria criteria = NW21{}=4
%t:13eM
detachedCriteria.getExecutableCriteria(session); S|yDGT1
return 7eZwpg?K
-&v0JvTJ9j
criteria.setProjection(Projections.rowCount .)FFl
XwU1CejP0
()).uniqueResult(); 4}YHg&@\d%
} ;1TQr3w
}, true); Di$++T8"
return count.intValue(); 4QNwu7TeR
} [,z>msEB.
} $V_w4!:Q
ah!RQ2hDrV
i(q a'*
r6 pz(rCs}
v?DA>
A_J!VXq
用户在web层构造查询条件detachedCriteria,和可选的 3|/zlKZz
i^}DIx{
startIndex,调用业务bean的相应findByCriteria方法,返回一个 DPl &e-`
~}K$z
PaginationSupport的实例ps。 jH 9.N4L
;,B $lgF
ps.getItems()得到已分页好的结果集 3.?oG5P#
ps.getIndexes()得到分页索引的数组 >-CNHb
ps.getTotalCount()得到总结果数 pr1>:0dg
ps.getStartIndex()当前分页索引 ?SoRi</1
ps.getNextIndex()下一页索引 <a
D}Ko(
ps.getPreviousIndex()上一页索引 :&O6Y-/B
XO/JnJ^B
G`u";w_
YJ 01-
P;p20+
E-$N!KY
lhFv2.qR
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 hOcVxSc.
gJ5|P
.
,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 - I j
Jn1(-
一下代码重构了。 a0B,[i
E
uk[ @1
我把原本我的做法也提供出来供大家讨论吧:
m<:g\_<
Eg]tDPN1
首先,为了实现分页查询,我封装了一个Page类: 8lT2qqlr
java代码: SBG.t:
d@<~u,Mt&F
77zDHq=
/*Created on 2005-4-14*/ Ap%tm)@1
package org.flyware.util.page; f}zv@6#&
xz vbjS W
/** X}j_k=, C
* @author Joa @ u2P&|:{
* +"SYG
*/ 2S_7!|j
publicclass Page { f\M;m9{(
mMtX:
/** imply if the page has previous page */ $pYT#_P!/
privateboolean hasPrePage; t3FfPV!P"
PQ`~qM:3st
/** imply if the page has next page */ # F|w_P
privateboolean hasNextPage; sT% ^W
a*KJjl?k
/** the number of every page */ P{h$> 6c
privateint everyPage; ; Uf]-uS
YW UCrnr
/** the total page number */ @m(ja@YC
privateint totalPage; I?IAZa)
jMB&(r
/** the number of current page */ r4FGz!U
privateint currentPage; [%yCnt
bG[)r
/** the begin index of the records by the current ~OQ/ |ws
n*GsM6Y&
query */ >z1q\cz
privateint beginIndex; DAt Zp%
]W>kbHImz
>`!Lh`n7_
/** The default constructor */ lDm0O)Dh!
public Page(){ j@+QwZL|
dAj;g9N/h
} ,Z6\%:/
OKp0@A)8
/** construct the page by everyPage auV<=1<zJ
* @param everyPage ;wvhe;!
* */ 4!
V--F
public Page(int everyPage){ 9Jhc5G
this.everyPage = everyPage; {E+o+2L
} BK16~Wl
wnoL<p
/** The whole constructor */ ct#3*]
public Page(boolean hasPrePage, boolean hasNextPage, :#=XT9
1'{A,!
^saH^kg1"
int everyPage, int totalPage, 9EqU
2~
int currentPage, int beginIndex){ 0qUBt9rA
this.hasPrePage = hasPrePage; !E+. (
this.hasNextPage = hasNextPage; 0X"D!G):
this.everyPage = everyPage; P,/=c(5\}
this.totalPage = totalPage; J$X{4
this.currentPage = currentPage; )k}UjU`!
this.beginIndex = beginIndex; I "<ACM
} @3F 4Lg6H|
W<AxctId
/** Ckc4U. t|
* @return hs5aIJ
* Returns the beginIndex. c0%.GcF0{
*/ ev_4!+ko
publicint getBeginIndex(){ B5iVT<:a
return beginIndex; +jPs0?}s
} 3h-C&C
Rt^~db
/** #M5R>&?Jqz
* @param beginIndex Nhnw'9
* The beginIndex to set. dq&N;kk
|
*/ wNX2*
publicvoid setBeginIndex(int beginIndex){ *Fe
this.beginIndex = beginIndex; l&f"qF?
} a$r<%a6
A*r6
/** XpH]CF
* @return L&WhX3$u
* Returns the currentPage. ksB-fOv*N
*/ Xj^Hy"HC^~
publicint getCurrentPage(){ dfss_}R
return currentPage; AD ,
} cR0OJ'w
5#|f:M]Bo|
/** I|27%i
* @param currentPage #@#/M)
* The currentPage to set. CQ`$' oy?W
*/ OcBKn=8
publicvoid setCurrentPage(int currentPage){ :Rq>a@Rp
this.currentPage = currentPage; YF]W<ZpY
} 9mEt**s
Ur
GjmPpKIu\
/** f""+jc1
* @return z ]@ Q
* Returns the everyPage.
9z9EK'g
*/ 0KQDw
publicint getEveryPage(){
yv@td+-"D
return everyPage; U0PQ[Y#\
} |V 3AA
l20fA-T
_I
/** nsRZy0@$t
* @param everyPage =%}++7#
* The everyPage to set. ]CFh0N|(L
*/ /Lf+*u>"
publicvoid setEveryPage(int everyPage){ PW[NW-S`c
this.everyPage = everyPage; Q/y^ff]=
} `pHlGbrW
&K1\"
/** QL<uQ`>(
* @return kFJ sB,2-
* Returns the hasNextPage. -W^jmwM
*/ : " ([i"
publicboolean getHasNextPage(){ Guc~]
B
return hasNextPage;
)N8[@
} LV^V`m0#
'g4t !__
/** yK$.wd2,
* @param hasNextPage
~s
:Ml
* The hasNextPage to set. C;u8qVI
*/ BRTM]tRZ
publicvoid setHasNextPage(boolean hasNextPage){ |\1!*Qp
this.hasNextPage = hasNextPage; F|eKt/>e
} cWd\Ki
Ly?%RmHK
/** !zhg3B#p
* @return 1kiS."77x
* Returns the hasPrePage. `30og]F0YJ
*/ "|2|Vju%
publicboolean getHasPrePage(){ "kE$2Kg
return hasPrePage; 7+,6m!4
} -|?I'~[#(
sd@JQ%O
/** 36NENzK
* @param hasPrePage 6vx0F?>_
* The hasPrePage to set. rRTAWAs%T
*/ FD}hw9VyF@
publicvoid setHasPrePage(boolean hasPrePage){ (BB&ZUdyv
this.hasPrePage = hasPrePage; DNP%]{J
} Rmq8lU
;3nR_6\
/** Ca SoR |
* @return Returns the totalPage. sXD.*D
*
$\W|{u`
*/ 0@FZQ$-
publicint getTotalPage(){ 1eg/<4]hA
return totalPage; g UfLw
} M^i^_}~S;
F"3LG"
/** 4CzT<cp
* @param totalPage =~)J:x\F
* The totalPage to set.
G_fP%ovh
*/ Km5#$IiP;
publicvoid setTotalPage(int totalPage){ c$cb2V7,
this.totalPage = totalPage; WUVRwJ 5
} QKj-"y[
[k"@n+%
}
>dnH
*rY@(|
6ty>0
$ekB+
t:cj
:UjF<V
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 _[yBwh
~Rs_ep'+Q2
个PageUtil,负责对Page对象进行构造: we6kV-L.
java代码: hAPWEh^
"bO\Wt#Mf
}y<p_dZI
/*Created on 2005-4-14*/ d)'am
3Q
package org.flyware.util.page; 0P(U^rkR~
P'.M.I@
import org.apache.commons.logging.Log; 0K\Xxo.=
import org.apache.commons.logging.LogFactory; N5 BC<pu
<A"T_Rk
/** *
u_nu>
* @author Joa
E *[dc
* _JlbVe[<
*/ 6m#V=4e*
publicclass PageUtil { W/(D"[:l%
()< E?D=
privatestaticfinal Log logger = LogFactory.getLog 'cs!(z-{x
}b9"&io
(PageUtil.class); % D]vKv~<
zEG6T *
/** -E6#G[JJ
* Use the origin page to create a new page QvM+]pdR6
* @param page sV8}Gv
a
* @param totalRecords <a)B5B>
* @return ^;";fr
Vw
*/ T3HAr9i%)
publicstatic Page createPage(Page page, int Yp_ L.TTb
/az}<r8
totalRecords){ up[9L|
return createPage(page.getEveryPage(), oF1{/ERS
3;M7^DM
page.getCurrentPage(), totalRecords); M2K{{pGJ[&
} 2nSX90@:
#fq%903=
/** <Fkm7ME]
* the basic page utils not including exception J~=bW\^I
MAhJ>qe8
p
handler BCDmce`=l
* @param everyPage `Gct_6
* @param currentPage 3[R<JrO
* @param totalRecords A1b</2
* @return page K gN=b
*/ ~7!=<MW
publicstatic Page createPage(int everyPage, int 42`%D
iD*%' #u
currentPage, int totalRecords){ *&WkorByW
everyPage = getEveryPage(everyPage); ~0}gRpMW
currentPage = getCurrentPage(currentPage); ;[-OMGr]#
int beginIndex = getBeginIndex(everyPage, Y(aEp_kV
+iS'$2)@
currentPage); s)Gnj;
int totalPage = getTotalPage(everyPage, 4@2<dw|*h
vrRbUwL!
totalRecords); B,Pbm|U1
boolean hasNextPage = hasNextPage(currentPage, [}xVz"8 V
h |Ofi
totalPage); 75@!j[QL<
boolean hasPrePage = hasPrePage(currentPage); |l4tR
CSKOtqKQ)
returnnew Page(hasPrePage, hasNextPage, u/wWP4'$J@
everyPage, totalPage, U0%T<6*H
currentPage, icO$9c
fQW1&lFT
beginIndex); `ChS$p"A
} &zuPt5G|
vbt0 G-%Z
privatestaticint getEveryPage(int everyPage){ YmrrZ&]q
return everyPage == 0 ? 10 : everyPage; mLEJt,X
} / //
:n#8/'%1
privatestaticint getCurrentPage(int currentPage){ \a#{Y/j3
return currentPage == 0 ? 1 : currentPage; PK C}!>2
} KT5amct
|`T$Iq
privatestaticint getBeginIndex(int everyPage, int lu_kir~
]=gNA
currentPage){ BlLK6"gJT
return(currentPage - 1) * everyPage; EZ,Tc;f=
} `w&A;fR!H
{GH0>
1&
privatestaticint getTotalPage(int everyPage, int 6TR` O
(vR9vOpJ
totalRecords){ (Q]Ww_r~
int totalPage = 0; ABx< Ep6
Mb!b0
if(totalRecords % everyPage == 0) <?2g\+{s9
totalPage = totalRecords / everyPage; Ci-CY/]s
else !W\za0p
totalPage = totalRecords / everyPage + 1 ; {yzo#"4Oy
{6I)6}w!k
return totalPage; <)qJI'u|
} HXeX!
<`Xt?K
privatestaticboolean hasPrePage(int currentPage){ C
vOH*K'
return currentPage == 1 ? false : true; )%+7"7.
} e,?qwZK:y
KgH_-REN
privatestaticboolean hasNextPage(int currentPage, #Dz. 58A
3(oB[9]s
int totalPage){ 1zc aI^e#
return currentPage == totalPage || totalPage == }R9>1u}6
1!S*z^LGl
0 ? false : true; v:IpZ;^
} <eh<4_<qF
ip+?k<]z
yC:C
} _x` oab0@
,
3&DA
Ajm
1F'x$~ZI
u2E}DhV
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。 $=9g,39
|e_'%d&
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 J1u&Ga
MqAN~<l [
做法如下: [*K.9}+G_
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Wx` $hvdq
xFScj0Y
的信息,和一个结果集List: m4on<5s/
java代码: iu iVr$E
1>=]lMW
zq'KX/o
/*Created on 2005-6-13*/ <{cf'"O7 )
package com.adt.bo; szs.B|3X@*
STL+tLJ
import java.util.List; Tg@:mw5
| /X+2K}3
import org.flyware.util.page.Page; ,UNnz&H+f
Ez+8B|0P
/** 0i>>CvAl}
* @author Joa ~,Kx"VK
*/ FL[,?RU?2
publicclass Result { AQGl}%k_
W.(Q
u-AE(
private Page page; i<M
F8$
w\1K.j=>|N
private List content; SQ057V>'=
HP,{/ $i:
/** XC!Y {lp
* The default constructor !8I80:e_~
*/ W+i&!'
public Result(){ iBk1QRdn
super(); y[';@t7CC
} ig ^x%!;
GE*%I1?]
/** "I
QM4:
* The constructor using fields fwi
-
* /<k]mY cu
* @param page M7=|N:/_
* @param content MxqIB(5k
*/ 9vBW CCf
public Result(Page page, List content){ 1cS*T>`
this.page = page; _2WW0
this.content = content;
t;}`~B
} !
u9LZ
sn8l3h)
/** *-&+;|mM
* @return Returns the content. '>GPk5Nq77
*/ U^kk0OT^
publicList getContent(){ T~
P<Gq},
return content; C6qGCzlG`
} ZyV^d3F@$
6$t+Q~2G!
/** X2`n&JE
* @return Returns the page. H#3Ma1z
*/ ft$!u-`
public Page getPage(){ !`dMTW
return page; |(=b
} :464~tHI[`
Qx8O&C?Ti
/** eC@b-q
* @param content !O4)YM
* The content to set. .ZupsS9l
*/ S&F;~
public void setContent(List content){ =3=8oF x8
this.content = content; 4!A(7
s4t
} {a,U{YJ\H
R]l2,0:
/** SP4(yJy&
* @param page D2f~*!vEnA
* The page to set. X$=/H 6R5Z
*/ e\}'i-
publicvoid setPage(Page page){ 6 )lWuY]e
this.page = page; @DKph!cr
} \*Z:w3;r
} m,Mg
w$aejz`[
rnC<(f22
EME}G42KN
oN,9#*PVL
2. 编写业务逻辑接口,并实现它(UserManager, j rg B56LL
/}S1e P6
UserManagerImpl) K<v:RbU|[1
java代码: a``Q}.ST
q*}$1 zb
%1rN6A!%
/*Created on 2005-7-15*/ .#LHj}u
package com.adt.service; tdNAR|
,#hNHFa'JH
import net.sf.hibernate.HibernateException; @DlN;r?Cv
jWK>=|)=c
import org.flyware.util.page.Page; o),@I#fM
[jTZxH<
import com.adt.bo.Result; ~sTn?~
_8wT4|z5
/** rfOrh^
* @author Joa G5UNW<P2C
*/ Wv30;7~
publicinterface UserManager { @4>?Y=#
|&~);>Cq2
public Result listUser(Page page)throws /KhY,G'Z
uk3PoB^>
HibernateException; \7Fp@ .S3
$SU<KNMZ
} zS `>65}e
3*e )D/lm
~uuM0POo
$Q`\-
DS7Pioa86
java代码: 6\m'MV`R!
4TcW%
jtPHk*>^wu
/*Created on 2005-7-15*/ UM. Se(kS
package com.adt.service.impl; hmv*IF.
QS<)*
import java.util.List; C`\yc_b9Pf
(n2=.9k!
import net.sf.hibernate.HibernateException; aK8X,1g%)
)Hqn
import org.flyware.util.page.Page; on f7V
import org.flyware.util.page.PageUtil; Olr'n% }
MYUL y2)
import com.adt.bo.Result; Wbi12{C
import com.adt.dao.UserDAO; ]F4|@+\9
import com.adt.exception.ObjectNotFoundException; SKJ'6*6
import com.adt.service.UserManager; tA-p!#V<k1
4iJ4g% ]
/** Jy0(g T
* @author Joa h[gKyxZ/t
*/ t=n@<1d
publicclass UserManagerImpl implements UserManager { bJL ,pe+u
t#7owY$^
private UserDAO userDAO; %D[6;PT
#G("Oh
/** }QJ6"s
* @param userDAO The userDAO to set. !8o;~PPVl
*/ jk5C2dy
publicvoid setUserDAO(UserDAO userDAO){ S,#UA%V"
this.userDAO = userDAO; {Yv5Z.L&(
} |@dY[VK>
_%<qZT
/* (non-Javadoc) -7m7.>/M
* @see com.adt.service.UserManager#listUser %kiPE<<x
i",oPz7
(org.flyware.util.page.Page) C 4\Q8uK
*/ ksQw|>K
public Result listUser(Page page)throws s5oU
ptTp63+
HibernateException, ObjectNotFoundException { 3E;<aCG?
int totalRecords = userDAO.getUserCount(); b+THn'2
if(totalRecords == 0) j8ag}%
throw new ObjectNotFoundException kj!mgu#T
g;!,2,De}
("userNotExist"); j6BFh=?D
page = PageUtil.createPage(page, totalRecords); %>,Kd6bdg
List users = userDAO.getUserByPage(page); ./}W3
returnnew Result(page, users); EV N:3
} u]Dds;~"b
?yAjxoE~?
} E=l^&[dIl
Q5tx\GE
d7v_>
Dqm;twd>
r~T3Ieb
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 q%MLj./?[
3 ~\S]
询,接下来编写UserDAO的代码: %s[
n2w
3. UserDAO 和 UserDAOImpl: 2-gI@8NPI
java代码: xu*dPG)v
mjbV^^>
SgY\h{{sP
/*Created on 2005-7-15*/ Bc51
0I$c
package com.adt.dao; w&LL-~KI+
n }4L q^$
import java.util.List; S$i3/t
??=7pFm
import org.flyware.util.page.Page; $|}PL[aA#
6#1:2ZHKG
import net.sf.hibernate.HibernateException; Dhp|%_>
\FjY;rqfKe
/** *]* D^'
* @author Joa rqYx\i?
*/ [USE&_RN
publicinterface UserDAO extends BaseDAO { ah0
q<wQ/m
publicList getUserByName(String name)throws T>pz?e^5&
f`8mES'gc8
HibernateException; #BX^"J{~
}
OAH/BW
publicint getUserCount()throws HibernateException; I xE}v%&
o|7
h
publicList getUserByPage(Page page)throws f)!7/+9>
Y!lc/[8
HibernateException; y7Sj^muBY
JM Ikr9/$
} '.d]n(/lZd
@2)ImgK[
n ^_B0Rkv
{]dH+J7
\P7y&`|
java代码: $(eqZ<y
]*JH~.p
6i_dL|c
/*Created on 2005-7-15*/ k;?E,!{
package com.adt.dao.impl; #~`]eM5`J
N3rQ]HZiP
import java.util.List; Z7Xic5PI{4
Y'v;!11#
import org.flyware.util.page.Page; 5RhP^:i@C
?br 4 wl
import net.sf.hibernate.HibernateException; Ug,23
import net.sf.hibernate.Query; o!ycVY$yW
ZMI
vzQYI
import com.adt.dao.UserDAO; O\KSPy7YQ
;m cu(J
/** /yS/*ET8
* @author Joa KHJk}]K
*/ ![a~y`<K,
public class UserDAOImpl extends BaseDAOHibernateImpl Z* L{;
AV*eGzz`
implements UserDAO { Y;6%pm $
d65t"U
/* (non-Javadoc) l9X\\uG&
* @see com.adt.dao.UserDAO#getUserByName ,3E9H&@j
?\$\YX%/p
(java.lang.String) W:z!fh-
*/ +1j+%&).
publicList getUserByName(String name)throws N"wp2w
8QNd t
HibernateException { DR w;.it2
String querySentence = "FROM user in class v5N2$Sqp*
eq#x~O4
com.adt.po.User WHERE user.name=:name"; #\)tz z
Query query = getSession().createQuery cXo^.u
Lb}
cjI:
(querySentence); C#A\Rfi
query.setParameter("name", name); czv )D\*
return query.list(); Qo;#}%}^^
} hfuGCD6F`
C5^eD^[c
/* (non-Javadoc) qTl/bFD
* @see com.adt.dao.UserDAO#getUserCount() [M{EO)
*/ xFY<
ns
publicint getUserCount()throws HibernateException { p~xrl jP$
int count = 0; A,)G$yT\
String querySentence = "SELECT count(*) FROM 2og8VI
/NDuAjp[@
user in class com.adt.po.User"; p!~{<s]
Query query = getSession().createQuery 'F[ C 4
L!]~J?)
(querySentence); /-W-MP=Wd
count = ((Integer)query.iterate().next }lzQMT
m*^|9*dIC
()).intValue(); ]O;Hlty(g
return count; Iu -CXc
} a} w%k
OLdD3OI
/* (non-Javadoc) Fc"&lk4e
* @see com.adt.dao.UserDAO#getUserByPage F|DKp[<]8
G2,r%|7ta
(org.flyware.util.page.Page) f @cs<x
*/ iWN-X
(
publicList getUserByPage(Page page)throws s;0eD5b>x
p~sfd
HibernateException { weOzs]uc
String querySentence = "FROM user in class [?$|
dLSnhZ
com.adt.po.User"; ;^,2
Qs M
Query query = getSession().createQuery N+vU@)_lC
ecH-JPm'
(querySentence); Vd{h|=J
query.setFirstResult(page.getBeginIndex()) '1}rQq Z
.setMaxResults(page.getEveryPage()); 9o7d3 ir)
return query.list(); $DfaW3bJ
} q-.e9eoc\
l}DCK
} ItTIU
=oF6|\]{;
:`Kr|3bQ
id-VoHdK
F$K-Q;r]<
至此,一个完整的分页程序完成。前台的只需要调用 {}3kla{
fxDY:l
userManager.listUser(page)即可得到一个Page对象和结果集对象 T2wn!N?r
X*~NE\
的综合体,而传入的参数page对象则可以由前台传入,如果用 '^l/e: (H3
{/BEO=8q2
webwork,甚至可以直接在配置文件中指定。 c4LBlLv4
{zGIQG9
下面给出一个webwork调用示例: 6,xoxNoPP3
java代码: >:]fN61#
g[;iVX^1&
Ar sMqb
/*Created on 2005-6-17*/ zJMKgw,i*
package com.adt.action.user; 33kI#45s
$/C<^}A
import java.util.List; +k"dN^K]D
x
0
import org.apache.commons.logging.Log; F$ .j|C1a
import org.apache.commons.logging.LogFactory; 'w%N(N tq
import org.flyware.util.page.Page; B>?Y("E
.Qh8I+Q%
import com.adt.bo.Result; xgR* j
import com.adt.service.UserService; v%<_Mh
import com.opensymphony.xwork.Action; FbM5Bqv
ke>\.|HT}
/** ~+>M,LfK
* @author Joa 8{+~3@T
*/ A2&&iL=j/
publicclass ListUser implementsAction{ _3p:q.
-R'p^cMA
privatestaticfinal Log logger = LogFactory.getLog Re1@2a>
d L%E0o
(ListUser.class); sW2LNE
l3MbCBX2
private UserService userService; CES FkAj~
M]` Q4\
private Page page; e+R.0E
<vt^=QA'
privateList users; Ql*/{#$
!CBx$1z
/* C6"!'6 W
* (non-Javadoc) 8)POEY4
* )Elr8XLw
* @see com.opensymphony.xwork.Action#execute() =cC]8Pz?
*/ 'fAD Dh}
publicString execute()throwsException{ KR^peWR
Result result = userService.listUser(page); .`'SL''c
page = result.getPage(); wCt+{Y3T
users = result.getContent(); T (2,iG8
return SUCCESS; )vU{JY;
} |C&eH$?~=R
)ql?}
/** Jj6kZK
* @return Returns the page. J$I1*~I4v
*/ \[oHt:$do
public Page getPage(){
.V.N^8(:a
return page; ;5|EpoM
} >A,WXzAK}S
&vF "I'V
/** nIi_4=Z
* @return Returns the users. 8S02
3
*/ .FXQ,7mZ-
publicList getUsers(){ P~qVr#eU
return users; p 5o;Rvr
} JZXc1R| 9
9bNIaC*M
/**
(KQt%]
* @param page B)Q'a3d#
* The page to set. ]Cz16e&=2
*/ Ur-^X(nL
publicvoid setPage(Page page){ "|G,P-5G"
this.page = page; IB6]Wj
} L,D>E
K?tk&0
/** \S<5b&G
* @param users 72,iRH
* The users to set. *@&
"MZ/M
*/ -0X> y
publicvoid setUsers(List users){ []]3"n
this.users = users; 0&\Aw'21
} 'AAY!{>
w?tKL0c
/** E&+^H
on
* @param userService
[dJ\|=
* The userService to set. 7asq]Y}<
*/ 'JMa2/7CG
publicvoid setUserService(UserService userService){ ?},ItJ#>)q
this.userService = userService; \$C4H
} `aUp&8{
} ifs*-f
=vc5,
6\3k0z
@EY}iK~
3I5WDuq
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, >.iw8#l
vs. uq
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 QP B"EW
T,uIA]
么只需要:
PBL^xlg
java代码: dNQSbp
.NT&>X~.V
I{zE73
<?xml version="1.0"?> 'u[o`31.
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork >t2b?(h/x
pCmJY
1.0//EN" "http://www.opensymphony.com/xwork/xwork- :6?&FzD`
g8+,wSE
1.0.dtd"> 1J"9r7\
IBkH+j
<xwork> 3}21bL
cf'}*$[S
<package name="user" extends="webwork- a{*'pY(R0$
l _O~v?
interceptors"> vB5iG|b}
9Nu#&_2R
<!-- The default interceptor stack name z8|9WZ:
Noxz kpMF
--> )6E*Qz
<default-interceptor-ref #>jH[Q
hZWK5KwT
name="myDefaultWebStack"/> yl<$yd0Zdu
R0mT/h2
<action name="listUser" ' 1'1T5x~
y] ]Vp~R:[
class="com.adt.action.user.ListUser"> 5?L:8kHsH
<param }8M`2HMFR
ev%t5NZ
name="page.everyPage">10</param> hav?mnVJ
<result 7(8
Jf<yTAm
name="success">/user/user_list.jsp</result> tc<M]4-
</action> [y[v]'
s<_LcQbt{
</package> /B@%pq
SE9u2Jk
</xwork> $;i$k2n:
%[\x%m)
d)1sP0Z_@
vDeG20.?Z
`V):V4!j),
w+9C/U;|s
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 R^M (fC
h"1"h.
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。 qVD!/;l
~q?"w:@;x
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 AzO3 (1:
Na 9l#
ym*#ZE`B!
o*wC{VP_
#D LT-G0
我写的一个用于分页的类,用了泛型了,hoho -~ O;tJF2
JNM@Q
java代码: /zG-\e U
'x,GI\;?
&>zy_)
package com.intokr.util; 9 CK\tx&
`k{ ff
import java.util.List; *VC4s`<
;TV'PJ
/** ^W[B[Y<k
* 用于分页的类<br> 5lHN8k=mm2
* 可以用于传递查询的结果也可以用于传送查询的参数<br> "l[V%f E
* =Mu'+,dT
* @version 0.01 W:{PBb"x8
* @author cheng iVpA@p
*/ d%_78nOh"
public class Paginator<E> { x U13fl
privateint count = 0; // 总记录数 kJ#[UCqzM
privateint p = 1; // 页编号 qSC~^N`
privateint num = 20; // 每页的记录数 zN)|g
privateList<E> results = null; // 结果 Xs%R]KOwt
=Qj+Ug'
/** LN~N
Fjs
* 结果总数 Jp.3KA>
*/ }W@#S_-e8
publicint getCount(){ #zSi/r/=1
return count; K.#,O+-Kg`
} `hK>bHj
{?
K|(C
publicvoid setCount(int count){ mHI4wS>()+
this.count = count; K.V!@bPlw9
} ,Y g5X
i^yH?bH @~
/** l?@MUsg+
* 本结果所在的页码,从1开始 N'eQ>2>O@
* gc,J2B]61
* @return Returns the pageNo. eHR&N.2
*/ VNr
publicint getP(){ yd0=h7s
return p; 5I)~4.U|,m
} EDq$vB
AT%*
~tr
/** \'s$ZN$k
* if(p<=0) p=1 @Hspg^
* 8u:v:>D.'
* @param p VW{aUgajO
*/ "o^bN 9=
publicvoid setP(int p){ Nh1e1m?
if(p <= 0) !7mvyc!'!
p = 1; ]/ZA/:Oa+
this.p = p; Lo|NE[b:G
} r6F{
S.Wh4kMUe
/** PmPyb>HK=P
* 每页记录数量 Qm35{^p+
*/ R
"/xne
publicint getNum(){ Wz6]*P`qv
return num; "t(1tWO1o
} ?Kx6Sf<i
)XmCy"xx
/** _"?c9
* if(num<1) num=1 ^f^-.X
*/ Lf,CxZL5
publicvoid setNum(int num){ ?r
-\%_J_(
if(num < 1) '2Q.~6
num = 1; KXoL,)Hl
this.num = num; qy7hkq.uX
} d'N(w7-Y
Ij;==f~G
/** rmY,v
* 获得总页数 88 Fb1!a5Z
*/ ntrY =Y
publicint getPageNum(){ L
Yh@ u1p
return(count - 1) / num + 1; JDC=J(B
} }Kvh`@CiJ
l 8O"w&
/** o/tVcv
* 获得本页的开始编号,为 (p-1)*num+1 b\SXZN)Be
*/ 8yHq7=
publicint getStart(){ TqENaC#&
return(p - 1) * num + 1; 33=Mm/<m$P
} 4mEzcwo'
:.C+?$iuX
/** @IEI%vH
* @return Returns the results. R(M}0JRm
*/ ??|d=4g\
publicList<E> getResults(){ e%PCe9
return results; AkxH
} =}~NRmmF
Y*5Z)h
1
public void setResults(List<E> results){ 6!4';2Q
this.results = results; NY4!TOp
} Qy4X#wgD
AyE%0KmraK
public String toString(){ v57N^DR{
StringBuilder buff = new StringBuilder ^36M0h|R
l'|E,N>X
(); cDfx)sL
buff.append("{"); t{+M|Y
buff.append("count:").append(count); p@#]mVJ>9
buff.append(",p:").append(p); ]b}B~jD
buff.append(",nump:").append(num); W\HLal
buff.append(",results:").append "4'kb
EYA/CI
(results); v2IEJ
buff.append("}"); 3Z_t%J5QZ$
return buff.toString(); :9(3h"
} +#0~:&!9
ksTzXG8
} \s,Iz[0Vfz
BTOA &Ag
/rqqC(1