Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 wvlM(
p
_q]Rt
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 1eMz"@Q9
>PoVK{&y
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 qfsu# R
RzN9pAe
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 ?$Ii_.
zM!2JC
。 -VkPy<)
xoyH5ZK@
分页支持类: *{s
3.=P.
zE1=*zO`
java代码: ZA.i\
;2
R>dd#`r"
Vc$y^|=
package com.javaeye.common.util; .Fm@OQr
!TeI Jm/l
import java.util.List; dI)
9@UL
_Sn45h@"
publicclass PaginationSupport { HAc1w]{(
[WW ~SOJe
publicfinalstaticint PAGESIZE = 30; %3mh'Z -[f
(V9 ;
privateint pageSize = PAGESIZE; ^{l$>e]
NH0uK
privateList items; vmIt!x
E>Lgf&R#W
privateint totalCount; ;cp,d~m rf
R;`C;Rbf
privateint[] indexes = newint[0]; D2MWrX
`$i/f(t6`
privateint startIndex = 0; +S
],){
1AAOg+Y@U"
public PaginationSupport(List items, int 0UOjk.~b
}b=Cv?Zg$m
totalCount){ _q=ua;I&
setPageSize(PAGESIZE); p}K.-S`MQ
setTotalCount(totalCount); %hCd*[Z}j
setItems(items); $c }-/U 8
setStartIndex(0); l" +q&3Zx
} .T\_4C
@23~)uiZa
public PaginationSupport(List items, int R/Z
zmb{
d34BJ<
totalCount, int startIndex){ HMqR%A
setPageSize(PAGESIZE); ^wxpinJ>
setTotalCount(totalCount); V?&P).5)
setItems(items); g[$4a4X
setStartIndex(startIndex); G-eSHv
} ndS8p]P&o(
/MZ^;XG
public PaginationSupport(List items, int Ri;_
8v[H|
Aqo90(jffx
totalCount, int pageSize, int startIndex){ r>cN,C
setPageSize(pageSize); &l?AC%a5
setTotalCount(totalCount); 6o<(,\ad[
setItems(items); |(3"_
setStartIndex(startIndex); i6 )HC
} {B[ }}wX$
2sH1),\
publicList getItems(){ x4-_K%
return items; =Hx]K8N )
} f[wxt n'r
6os{q`/Q])
publicvoid setItems(List items){ ($'5xPb
this.items = items; ]-cSTtO
} JsHD3
()e|BFL .
publicint getPageSize(){ RAj>{/E#W
return pageSize; h]pz12Yf
}
{[dY$
%uDH_J|^
publicvoid setPageSize(int pageSize){ ^MO})C
this.pageSize = pageSize; -{A*`.[v
} +aOQ'*g
p} {H%L
publicint getTotalCount(){ f"SK3hI$p
return totalCount; <.hutU*1
} q![`3m-d.
'
r/xBj[Z
publicvoid setTotalCount(int totalCount){ .?kq\.rQ
if(totalCount > 0){ OJ r~iUr
this.totalCount = totalCount; Go(Td++HS
int count = totalCount / ]i\;#pj}
n&3}F?
pageSize; GQ2/3kt
if(totalCount % pageSize > 0) ym_p49
count++; tmi)LRF
H
indexes = newint[count]; u(i=-PN_<
for(int i = 0; i < count; i++){ qyP={E9A
indexes = pageSize * ZlP+t>
MI)v@_1d
i; U=PTn(2
} ^@^K
<SVc
}else{ (dTQ,0
this.totalCount = 0; !cW!zP-B*p
} Up5 |tx7
} V.Tn1i-v
PU8dr| !
publicint[] getIndexes(){
fj'7\[nZ
return indexes; )3k?{1:
} <QD[hO^/
JJK-+a6cX
publicvoid setIndexes(int[] indexes){ Rqr>B(|
this.indexes = indexes; rFaG-R
} ty'/i!/\
2'u%
publicint getStartIndex(){ fZrh_^yH
return startIndex; LGK@taw^
} _!,Ees=b
^h^.;Iqr=
publicvoid setStartIndex(int startIndex){ in6*3C4
if(totalCount <= 0) (eSsx/
this.startIndex = 0; ")<5VtV
elseif(startIndex >= totalCount) /36gf
this.startIndex = indexes %j.n^7i]^:
I-#7Oq:Np
[indexes.length - 1]; )D ~ 5
elseif(startIndex < 0) >wb Uxl%{5
this.startIndex = 0; b0Dco0U(
else{ RFoCM^
this.startIndex = indexes ?tA%A
f-p$4%(
[startIndex / pageSize]; -iKoQkHt
} _s*p$/V\
} .><-XJ
-Aojk8tc
publicint getNextIndex(){ D -d
int nextIndex = getStartIndex() + x#gZC1$Y
nW}jTBu_K+
pageSize; i%[+C
if(nextIndex >= totalCount) [+Fajo;0
return getStartIndex(); a~ dgf:e`
else !o1IpTN
return nextIndex; 83 <CDjD
}
HQ]mDo
c0Pj})-
publicint getPreviousIndex(){ qsQ{`E0
int previousIndex = getStartIndex() - bi^Pk,'
Vl;zd=
pageSize; 5z =}o/?
if(previousIndex < 0) I]hjv
return0; H]7bqr
else sO}CXItC+j
return previousIndex; KA{&NFx
} *<X1M~p$
',K:.$My
} iI`vu
rVP{ ^Jdo
'v9M``
zw+RDo
抽象业务类 M\-[C!h,
java代码: =fJU+N+<
&,yF{9$G
C+g}+
/** ~(8f Uob
* Created on 2005-7-12 >lKu[nq;
*/ 8&M<?oe
package com.javaeye.common.business; ="v`W'Pd
eh>
|m>JY
import java.io.Serializable; L_aqr?Q
import java.util.List; 7'"qW"<
/QWXEL/M=
import org.hibernate.Criteria; Y[]I!Bc
import org.hibernate.HibernateException; :)i,K>y3i
import org.hibernate.Session; NU3TXO
import org.hibernate.criterion.DetachedCriteria; z~3GgR"1d
import org.hibernate.criterion.Projections; `+rwx
import 5:jme$BI
Arm'0)B>
org.springframework.orm.hibernate3.HibernateCallback; j#~~_VA~
import /Ry%K4$
)z\#
org.springframework.orm.hibernate3.support.HibernateDaoS c BZ,"kp-
Xdx8HB@L
upport; Ar[|M2|
tH4q*\U
import com.javaeye.common.util.PaginationSupport; g$^-WmX\m
~TsRUT
public abstract class AbstractManager extends /#
]eVD
wN58uV '
HibernateDaoSupport { Hy1$Kvub
}Nd1'BVf
privateboolean cacheQueries = false; >}\s-/
>$TvCw
privateString queryCacheRegion; "[!b5f3!I
'tY(&&
publicvoid setCacheQueries(boolean +<.o,3
LRts
W(A/
cacheQueries){ !^&VZh
this.cacheQueries = cacheQueries; 9:Oz-b
} oKsArZG
?&-1(&
publicvoid setQueryCacheRegion(String #Tei0B7
,h*N9}xYTi
queryCacheRegion){ rJkJ/9s
this.queryCacheRegion = :\JCxS=EW
\
a,}1FS
queryCacheRegion; zWhj>Za
} YLi6GY
/AADFa
publicvoid save(finalObject entity){ 8QK8q:|
getHibernateTemplate().save(entity); JRw,${W
} KILX?Pt[7
U 7.k Yu
publicvoid persist(finalObject entity){ tE_n>~Zs
getHibernateTemplate().save(entity); `WN80d\)&
} >5#}/G&
bj}Lxc ],
publicvoid update(finalObject entity){ RrvC}9ar
getHibernateTemplate().update(entity); IH dA2d?.]
} ,|s*g'u
A5J41yH
publicvoid delete(finalObject entity){ v}N\z2A
getHibernateTemplate().delete(entity); |(Mxbprz
} {'tfU
"WuUMt
publicObject load(finalClass entity, mjWU0.
Y|Q(JX
finalSerializable id){ E`I(x&_
return getHibernateTemplate().load n)"JMzjQ<
-f&vH_eK
(entity, id); 'I&0$<
} %K4M`R|2]
J)Y`G4l2@
publicObject get(finalClass entity,
R%RxF=@
/uX*FZ
finalSerializable id){ D$K'Qk
return getHibernateTemplate().get #p@GhI!6
'"E!av>
(entity, id); ! e$ZOYe
} {%G9iOV.
Or.u*!od&
publicList findAll(finalClass entity){ 'z5jnI
return getHibernateTemplate().find("from e|!'
eZAMV/]jH
" + entity.getName()); (&Rk#i U
2
} (Fon!_$:
zP%s] >hH
publicList findByNamedQuery(finalString nH?6o#]N
\hgd&H0UU
namedQuery){ P0}{xq'k9v
return getHibernateTemplate =yZq]g6Q
Zh;wQCDj
().findByNamedQuery(namedQuery); }W8A1-UF
} B6
(\1
p"p~Bx
publicList findByNamedQuery(finalString query, HvG %##
u_$4xNmQ
finalObject parameter){ dEtjcId
return getHibernateTemplate 2$5">%?
+FqD.= 8
().findByNamedQuery(query, parameter); >-I <`y-H
} 4T(d9y
O*l,&5
publicList findByNamedQuery(finalString query, }x`Cnn
H]R/=OYBUh
finalObject[] parameters){ GNMOHqg4
return getHibernateTemplate [w'Q9\,p
|-}.Y(y
().findByNamedQuery(query, parameters); \)No?fB
} H%@f ^
5OI.Ka
publicList find(finalString query){ B1)Eo2i#
return getHibernateTemplate().find Fb(@i
bPxL+
+
(query); %US&`BT!
} sQ#e 2
hz4?ku
publicList find(finalString query, finalObject s6 g"uF>k
[[IMf-]
parameter){ Pl/ dUt_
return getHibernateTemplate().find =|z:wlOs
;zJb("n
(query, parameter); 71R,R,
} AhN3~/u%7
/ovVS6Ai
public PaginationSupport findPageByCriteria d-_V*rYU
X?'cl]1?
(final DetachedCriteria detachedCriteria){ +_7a/3kh
return findPageByCriteria :,0(aB
~r.R|f]IQ
(detachedCriteria, PaginationSupport.PAGESIZE, 0); (L*GU 7m;
} jXE:aWQht
B>L7UQ6_[
public PaginationSupport findPageByCriteria !{.CGpS ]
{1OxJn1hd
(final DetachedCriteria detachedCriteria, finalint $o?U=
jG[Vp b
startIndex){ 6/8K2_UeoW
return findPageByCriteria (NvjX})eh
T"z<D+pN
(detachedCriteria, PaginationSupport.PAGESIZE, Jr!BDg
;bB#Pg
startIndex); M9W
zsWM
} o4kLgY !Q
&" t~d}Rg
public PaginationSupport findPageByCriteria w.k9{f
t<##0#xS.
(final DetachedCriteria detachedCriteria, finalint FYYc+6n
T%eBgseS
pageSize, JI-i7P
finalint startIndex){ fwz:k]vk
return(PaginationSupport) G{} 2"/
bXnUz?1!d
getHibernateTemplate().execute(new HibernateCallback(){ UUV5uDe>i
publicObject doInHibernate F<I*?${[
;98&5X\u<
(Session session)throws HibernateException { [nO3%7t@
Criteria criteria = $K^l=X
#h[>RtP:
detachedCriteria.getExecutableCriteria(session); (I}owr 5:
int totalCount = eK:?~BI!
wN!\$i@E:
((Integer) criteria.setProjection(Projections.rowCount P?h1nxm`'
T/'z,,Y
()).uniqueResult()).intValue(); $IE}fgA@5
criteria.setProjection Z0L($
AabQ)23R2
(null); =PRQ3/?5
List items = ,-AF8BP
Czjb.c:a.Y
criteria.setFirstResult(startIndex).setMaxResults L\2"1%8Wj
H[~ D]RG}'
(pageSize).list(); <!sLfz?
PaginationSupport ps = @Ul3J )=m
MQ!4"E5"j
new PaginationSupport(items, totalCount, pageSize, epiviCYC
B"&-) (
startIndex); :8)Jnh\5
return ps; 'v]0;~\mp>
} $NVVurXa
}, true); YcobK#c
} t<8)h8eW
MIZdk'.U
public List findAllByCriteria(final G]ek-[-
j?N<40z
DetachedCriteria detachedCriteria){ U4!KO;Jc
return(List) getHibernateTemplate xfb .Z(
G+<XYkz*
().execute(new HibernateCallback(){ 0*XsAz1,9
publicObject doInHibernate "'z}oS
Fe0M2%e;|
(Session session)throws HibernateException { *-9i<@|(U^
Criteria criteria = q2EDrZ
F=Bdgg9s
detachedCriteria.getExecutableCriteria(session); @Y/&qpo$#W
return criteria.list(); 2#.s{ Bv
} %P0
}, true); 0&,D&y%
} hQ@k|3=Re
t.9s4 9P
public int getCountByCriteria(final (.:*GUg
unFRfec{
DetachedCriteria detachedCriteria){ ircF3P>a?
Integer count = (Integer) a}%f+`z
sq2:yt
getHibernateTemplate().execute(new HibernateCallback(){ /2Wg=&H
publicObject doInHibernate BXYHJ
sQ}|Lu9hZ
(Session session)throws HibernateException { vu+g65"
Criteria criteria = Ah2 {kK
&gp&i?%X9b
detachedCriteria.getExecutableCriteria(session); i{6&/TBnr
return "UTW(~D'
Xq;|l?,O
criteria.setProjection(Projections.rowCount \|0z:R;X
?/o 8f7Z
()).uniqueResult(); w,p'$WC*
} FLW VI4*
}, true); gQPw+0w
return count.intValue(); QJ XP-
} <<0sv9qw1
} I<#X#_YP
$+Ze"E
Lk !)G'42
-V}oFxk]q
nFQuoU]ux
uY.Ns ?8
用户在web层构造查询条件detachedCriteria,和可选的 A08kwYxiW
X84T F~2Y
startIndex,调用业务bean的相应findByCriteria方法,返回一个 =cEsv&i
3mHzOs\jU
PaginationSupport的实例ps。 lOt7ij(,L
e-rlk5k%f
ps.getItems()得到已分页好的结果集 MZV$YD^S
ps.getIndexes()得到分页索引的数组 relt7 sK
ps.getTotalCount()得到总结果数 q!c=f!U?\l
ps.getStartIndex()当前分页索引 zGtJ@HbB
ps.getNextIndex()下一页索引 _Tj&gyS
ps.getPreviousIndex()上一页索引 O >h`
I0+6p8,
%M
iv8
, -Hj
>/A]C$?3
WML--<dU
c& ;@i$X(
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ..JRtuM-v
U823q-x
,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 M8~3 0L
#s{^fUN6
一下代码重构了。 '{ _ X1
e#*3X4<\K
我把原本我的做法也提供出来供大家讨论吧: bG]0|
1d< b\P0
首先,为了实现分页查询,我封装了一个Page类: 3:iEt (iCI
java代码: S"&Gutu3o
>`AK'K8{M
PuJ3#H
T
/*Created on 2005-4-14*/ %+l95Dv1
package org.flyware.util.page; )k Wxp
~z:]rgX
/** +0&^.N
* @author Joa T]%-Ri
* Y!L-5|G
*/
t1hQ0 B
publicclass Page { E:K4k <
$9X+dvu*
/** imply if the page has previous page */ 6.)ug7aF
privateboolean hasPrePage; LTe ({6l0
gF,=rT1:>r
/** imply if the page has next page */ }i8y/CA
privateboolean hasNextPage; #^L&H
oo6
^s{F f+]W
/** the number of every page */ 0#WN2f, <:
privateint everyPage; ?b+Y])SJK
;}E}N:A
/** the total page number */ )g'J'_Sl
privateint totalPage; C][$0
j,.M!q]
/** the number of current page */ q@wD@_
privateint currentPage; G?}?>O
8NfXYR#
/** the begin index of the records by the current ?z.?(xZ 6
!`e`4y*N
query */ 5!?5S$>
privateint beginIndex; e6taQz@}
"B{3q`(
Q'n+K5&p
/** The default constructor */ 23tX"e
public Page(){ _z#"BN
~3.*b%,
} M[`[+5v
A&M_ J
/** construct the page by everyPage _3aE]\O[
* @param everyPage Ca0sm
* */ `$/a-K}
public Page(int everyPage){ 2jyWkAP'
this.everyPage = everyPage; f0H.$UAL
} d}Pfj=W
><}nZ7
/** The whole constructor */ 7Vy_Cec1
public Page(boolean hasPrePage, boolean hasNextPage, u1 Q;M`+>
+ALrHFG
@/:4beh
int everyPage, int totalPage, 4NID:<
int currentPage, int beginIndex){ %4nf(|8n
this.hasPrePage = hasPrePage; )9nW`d+
this.hasNextPage = hasNextPage; I#2$CSJ
this.everyPage = everyPage; qj;i03 +@
this.totalPage = totalPage; 1L*[!QT4
this.currentPage = currentPage;
b WNa6x
this.beginIndex = beginIndex; Sh(ys*y>
} }>6e-]MHfR
He=C\"
/** J:Fq i p
* @return f5*qlQJFz\
* Returns the beginIndex. ms0V1`
*/ HXU#Ux
publicint getBeginIndex(){ kf'(u..G
return beginIndex; |J!mM<*K
} ?xqS#^Z
W^8
/** JPZp*5c6A
* @param beginIndex 5a/A?9?,
* The beginIndex to set. :k_&Zd j,B
*/ ~2k.x*$
publicvoid setBeginIndex(int beginIndex){ IVPN=jg?
this.beginIndex = beginIndex; ,y]-z8J
} /O:4u_
U*~-\jN1pb
/** * F%1~
* @return LG:k}z/T
* Returns the currentPage. =H)]HxEEM
*/ W+a/>U
publicint getCurrentPage(){ f!kZyD7
return currentPage; y-26\eY^P
} aM
$2lR])J
k( Sda>-
/** 9>4 #I3
* @param currentPage >>T7;[h
* The currentPage to set. {j$2=0Cec
*/ O(I^:_eH
publicvoid setCurrentPage(int currentPage){ Jpduk&u
this.currentPage = currentPage;
ULt5Zi
} ,;t:x|{%
fJr
EDj4(
/** ;\w3IAa|V
* @return :j`f%Vg~x
* Returns the everyPage. 3*I\#Z4p1
*/ ht%qjE
publicint getEveryPage(){ RK.lzVaY
return everyPage; 4tm%F\Izy
} "a2|WKpD
v'?Smd1v
/
/** ^>an4UJt
* @param everyPage R*pPUw\yn
* The everyPage to set. SY5}Bu#
*/ _p8u
&TZ
publicvoid setEveryPage(int everyPage){ ke2dQ^kc4
this.everyPage = everyPage; >0@w"aKn
} 0JtM|Mg
[lML^CYQ
/** 5,,'hAq_
* @return ,G0"T~
* Returns the hasNextPage. }kt%dDU
*/ i&H^xgm
publicboolean getHasNextPage(){ bz>\n"'
return hasNextPage; .I~:j`K6
} rSv,;v
)&T 5/+
/** ;@S'8
* @param hasNextPage Jd/d\P
* The hasNextPage to set. '1DY5`i{
*/ MUbKlX
publicvoid setHasNextPage(boolean hasNextPage){ <O=0 ^V
this.hasNextPage = hasNextPage; .+S%hT,v6i
} fNi&r0/-t
&iWTf K7
/** G0!6rDu2,
* @return Eb~vNdPo
* Returns the hasPrePage. ! $mY.uu
*/ #W8F_/!n|
publicboolean getHasPrePage(){ B`)sc ~u
return hasPrePage; iPl,KjGk
} Q4 &P\V
MS#"TG/)
/** A-L1vu;
* @param hasPrePage 64mh. j
* The hasPrePage to set. w tGS"L
*/ W*s=No3C
publicvoid setHasPrePage(boolean hasPrePage){ ch%zu%;f
this.hasPrePage = hasPrePage; 'qEw]l
} Ps.xY;Y
!S&/Zp
/** 8y5"X"U
* @return Returns the totalPage. :vIJ>6lIR
* >'Lkn2WI
*/ C.ynOo,W
publicint getTotalPage(){ l'4 <^q
return totalPage; 1o/(fy
} sg-^ oy*^
93D}0kp
/** yw:%)b{
* @param totalPage (PH7nW7
* The totalPage to set. b]?5r)GK
*/ }l+_KA
publicvoid setTotalPage(int totalPage){ |APOTQV
this.totalPage = totalPage; zQ:nL*X'Z"
} JE{cZ<NNH
Ga9iPv
} g&$5!ifgi
.9Oj+:n
~M*
UMF^
=Bc{0p*
N/WtQSl
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 !Z>,dN
~sn3_6{
个PageUtil,负责对Page对象进行构造: "LDNkw'
java代码: yqK_|7I+
6'mZM=d
%4rlB$x
/*Created on 2005-4-14*/ < ~CY?
package org.flyware.util.page; w(_:+-rqQ<
-">Tvi4
import org.apache.commons.logging.Log; ueU "v'h\
import org.apache.commons.logging.LogFactory; h*KDZ+{)
4e\w C
/** ! 1?u0
* @author Joa K)l*$h&-
* cahlYv'
*/ 8hy1yt6t4~
publicclass PageUtil { [-#1;!k
HL[V}m
privatestaticfinal Log logger = LogFactory.getLog N1g;e?T':
;j;U9-oh
(PageUtil.class); MW^FY4V1m
S9[Up}`
/** G M;uwL#
* Use the origin page to create a new page uCW}q.@4
* @param page &{WEtaXaa
* @param totalRecords bZK`]L[
* @return j&.JAQ*2;
*/ { ~{D(k
publicstatic Page createPage(Page page, int 2.j0pg .
>>R)?24,<
totalRecords){ +LWgby4q
return createPage(page.getEveryPage(), 70*yx?T V
{Xpjm6a7
page.getCurrentPage(), totalRecords); e6jdSn
} b0%#=KMi
hI<$lEB
/** hZe9 Y?)
* the basic page utils not including exception -xH3}K%
q_;# EV
handler :/Y4I)'
* @param everyPage Q3)[
*61e
* @param currentPage RKs_k`N0
* @param totalRecords 8fWnKWbbjw
* @return page ~te{9/
*/ aC'#H8e|j
publicstatic Page createPage(int everyPage, int |])Ko08*tE
mp]UUpt
currentPage, int totalRecords){ ok&v+A
everyPage = getEveryPage(everyPage); 2)^T[zHe
currentPage = getCurrentPage(currentPage); h2]GV-
int beginIndex = getBeginIndex(everyPage, 7x
|Pgu(
Z q}Cl'f
currentPage); Me,AE^pgL'
int totalPage = getTotalPage(everyPage, 7 Uu
v}z{OB
totalRecords); )i.\q
boolean hasNextPage = hasNextPage(currentPage, ~65lDFY/
a)L=+Z
totalPage); oP<E)
boolean hasPrePage = hasPrePage(currentPage); @)@hzXQ
!jJH}o/KW
returnnew Page(hasPrePage, hasNextPage, !3at(+4
everyPage, totalPage, e-{4qt
currentPage, .Wci@5:3
~hA;ji|I
beginIndex); {[B` q
} [SLBA_d
o{QPW
privatestaticint getEveryPage(int everyPage){ 3D7phq>.q
return everyPage == 0 ? 10 : everyPage; Riz!HtyR
} <~qhy{hRn
@)wNINvD
privatestaticint getCurrentPage(int currentPage){ !g-19at
return currentPage == 0 ? 1 : currentPage; 2KmPZ&r
} oG;;='*
bPdbKi{j@
privatestaticint getBeginIndex(int everyPage, int & 5YI!; q,
Mio~CJ"?
currentPage){ d~J4&w
return(currentPage - 1) * everyPage; HPR*:t
} E
:Y
*;
e6?h4}[+*
privatestaticint getTotalPage(int everyPage, int [HhdeLOX
KIUa
totalRecords){ 3F0:v,+;
int totalPage = 0; mM7S9^<UH
! Q5ip'L
if(totalRecords % everyPage == 0) wMB<^zZmv
totalPage = totalRecords / everyPage; f)+fdc
else =w!14@W
totalPage = totalRecords / everyPage + 1 ; aTy&"
>m{)shBX
return totalPage; #_bSWV4
} .ZrQ{~t
r'q9N
privatestaticboolean hasPrePage(int currentPage){ UI 7JMeV
return currentPage == 1 ? false : true; ^4yFLqrC
} k w!1]N
`jb?6;15
privatestaticboolean hasNextPage(int currentPage, WVf>>E^1
5sq#bvfJ o
int totalPage){ \TrhJ
return currentPage == totalPage || totalPage == h&vq}
ukr
a)>Y[|
0 ? false : true; *qE[Y0Cd
} of^N4
0Kjm:x9T
s!2pOH!u
} V4!RUqK
!R WX1Z
zrt8ze=Su
@"H+QVJ@
ht S5<+Y
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。 *~|xj,md
)A['+s
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 ![iAALPNl
Oav^BhUO
做法如下: INrUvD/*
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 D;|4ZjM-
swnov[0
的信息,和一个结果集List: h"')D
java代码: !G#3jh:kiY
J+LFzl07q
]v 6u
/*Created on 2005-6-13*/ cv0}_<Tyx
package com.adt.bo; g/4.^c
q"A( l
import java.util.List; d7u"Z5t
h?DMrYk_%#
import org.flyware.util.page.Page; +aV>$Y
Ajhrsa\~a
/** g Bq, So
* @author Joa 8lt P)K4
*/ 2|#3rF
publicclass Result { ue$\i =jw
.c+RFX@0
private Page page; LeY\{w
HT5G HkT
private List content; Z|
+/Wl-h
Ne.W-,X^cL
/** }yU,_:
* The default constructor /"Om-DK%
*/ h8O[xca/~
public Result(){
h.g11xa
super(); 9QI\[lT&
} ?jBna
~
~-6Kl3Y
/** q'M-a tE.
* The constructor using fields oHbEHS61
* 'd1E~A
* @param page #Qy*zU#9
* @param content >\$qF
*/ JB'q_dS}
public Result(Page page, List content){ r%$-F2.p
this.page = page; >)U 7$<&b
this.content = content; 6A/Nlk.
} *KFsO1j
U^~K-!0
/** >u~ [{(d ,
* @return Returns the content. >&aFSL,f
*/ rGRxofi.
publicList getContent(){ v)+wr[Qs
return content; Jnm{i|6N
} f
7et
7^Jszd:c08
/** }jfU qqFd
* @return Returns the page. MlsF?"H p
*/ 9 YU7R)
public Page getPage(){ 7
4aap2^
return page; $[[6N0}*:
} or~o'
OgS6#X
/** qw0tw2|
* @param content z(>{"t<C
* The content to set. #v')iR"
*/ {`KgyCW:
public void setContent(List content){ ^Q4w<sX'
this.content = content; ||}|=Sz
} <Ky\ ^
s+tS4E?
/** C%"h1zWE:
* @param page <k5FlvE2
* The page to set. $ZXy&?4
*/ r['T.yo
publicvoid setPage(Page page){ 0d:t$2~C
this.page = page; ay'=M`uO_
} [={pFq`
} Fkz+Qz
R',|Jf=`
YurK@Tq7
|I7P0JqP
3>0/WbA:7E
2. 编写业务逻辑接口,并实现它(UserManager, Xe*@`&nv@
R?>a UFM
UserManagerImpl) -t?S:9[w
java代码: q!""pr<n
^Cyx"s't
x7l)i!/$
/*Created on 2005-7-15*/ /!JpmI
package com.adt.service; g84~d(\?
FD#?pVyPn^
import net.sf.hibernate.HibernateException; CTR|b}!
Zx55mSfx:
import org.flyware.util.page.Page; 8S@ ~^D
EFf<|v
import com.adt.bo.Result; mh.0%
9`9
~ceGx
/** gJ c5Y
* @author Joa mv SNKS
*/ =a?l@dI]
publicinterface UserManager { {.H}+ @0
|vTirZP
public Result listUser(Page page)throws .-`7Av+7
Rr4r[g#
HibernateException; s3_i5,y
Z=R>7~H
} (~}yt .7K
=d7 lrx+z
zBB4lC{q
"KW\:uc /
QCa$<~c
java代码: /%Rz`}
g*-
K!X6l
i <bFF03*S
/*Created on 2005-7-15*/ =:6Y<ftC
package com.adt.service.impl; &]pW##
TxN#3m?G
import java.util.List; A:p7\Kp;5}
;TMH.E,h:
import net.sf.hibernate.HibernateException; `8xe2=Ub
6rt.ec(
import org.flyware.util.page.Page; .4_EaQ;jX
import org.flyware.util.page.PageUtil; isDBNXV:
8\. #
import com.adt.bo.Result; 0D|^S<z6
import com.adt.dao.UserDAO; o*f7/ZP1o
import com.adt.exception.ObjectNotFoundException; (IIOKx _
import com.adt.service.UserManager; V`S6cmwdc\
&UbNp8h
/** L;fhJ~r
* @author Joa O#Xq0o
*/ I#Iu:,OT
publicclass UserManagerImpl implements UserManager { sA3 4`ZAa
' "~|L>F%G
private UserDAO userDAO; N:d`L+tcc
GLnj& Ve
/** )3'/g`c
* @param userDAO The userDAO to set. 8$OE<c?#5n
*/ 2!7wGXm~U
publicvoid setUserDAO(UserDAO userDAO){ .9lx@6]+
this.userDAO = userDAO; ]#j]yGV
} Rw^4S@~T
V_Wv(G0-\
/* (non-Javadoc) `-]*Qb+
* @see com.adt.service.UserManager#listUser f@[q# }6
]*%0CDY6`N
(org.flyware.util.page.Page) wcsUb9(
*/ #
T$^{/J
public Result listUser(Page page)throws Ls5|4%+&
3PpycJ}
HibernateException, ObjectNotFoundException { %:N5k+}
int totalRecords = userDAO.getUserCount(); L:XnW1(Or
if(totalRecords == 0) oSx]wZZ
throw new ObjectNotFoundException $khWu>b
oq^#mJL
("userNotExist"); s$&:F4=?
page = PageUtil.createPage(page, totalRecords); :f 1*-y
List users = userDAO.getUserByPage(page); 'r(}7>~fC
returnnew Result(page, users); -XkCbxZ
} !RFlv
'F5&f9A
} 8nt:peJ$+
#)GL%{Oa
-+Kx^V#'R
+sQ=Uw#e
"sUL"i
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 }/SbmW8(1
a7%5Qg9B;
询,接下来编写UserDAO的代码: nP0|nPWz#
3. UserDAO 和 UserDAOImpl: O<Ht-TN&
java代码: ou6yi;
l%
zy
$FNj>1
/*Created on 2005-7-15*/ 8}XtVF;
package com.adt.dao; L'H'E,
vCFMO3
import java.util.List; `rbTB3?
7xO
=:*
import org.flyware.util.page.Page; ;R@zf1UYA
R',Q)<
import net.sf.hibernate.HibernateException; r[q-O&2&
QPg
QM6
/** O:{I9V-=>s
* @author Joa |XtN\9V.
*/ !X`
5
publicinterface UserDAO extends BaseDAO { SBzJQt@Hs
W[AX?
publicList getUserByName(String name)throws Kxn/@@z>u
|bQKymS
HibernateException; O B_g:T
q}*(rR9/Br
publicint getUserCount()throws HibernateException; jdK~]eld=
)c^Rc9e/
publicList getUserByPage(Page page)throws 8uP,#D<wZ
K;k_MA310
HibernateException; /$|C s
4;<?ec(dc
} W.r0W2))(
z4HIDb
eY-W5TgU
Xjw>Qws
&-:ZM0Fl
java代码:
WUvrC
Mi%i_T^i
r?nvJHP
/*Created on 2005-7-15*/ @mSdksB/L
package com.adt.dao.impl; X#EMmB!
T&oY:1D,g
import java.util.List; [ %cW ?@
s{(aW5$!s
import org.flyware.util.page.Page; f-F+Y`P
3=RV Jb
import net.sf.hibernate.HibernateException; |F=!0Id<
import net.sf.hibernate.Query; 9.{u2a\
({v$!AAv
import com.adt.dao.UserDAO; ^
|z|kc
O:IU|INq8
/** JF!JY( U,
* @author Joa mKugb_d?
*/ @%d g0F}h
public class UserDAOImpl extends BaseDAOHibernateImpl ]i(tou-[i
)a
AKO`
implements UserDAO { -*~= 4m<
Dt%Gv0
/* (non-Javadoc) \T`InBbf
* @see com.adt.dao.UserDAO#getUserByName wN>k&J
k|k
(java.lang.String) 0"ksNnxK
*/ )r3}9J
publicList getUserByName(String name)throws :hJHjh
n+QUT
HibernateException { Ebw1 %W KC
String querySentence = "FROM user in class [fx1H~T<
w#vSZbh
com.adt.po.User WHERE user.name=:name"; Zyt,D|eWj
Query query = getSession().createQuery HY0q!.qog
#tg,%*.s
(querySentence); >Akrbmh5
query.setParameter("name", name); 9>yLSM,!rS
return query.list(); '3TwrY?-
} H.*:+
f!%G{G^`
/* (non-Javadoc) AFE6@/'
* @see com.adt.dao.UserDAO#getUserCount() F0:|uC4
*/ Aslh}'$}-
publicint getUserCount()throws HibernateException { #5)0~4%l
int count = 0; qB6@OS
String querySentence = "SELECT count(*) FROM Ir&rTGFN
q,`"Z)97
user in class com.adt.po.User"; FJXYKpY[r
Query query = getSession().createQuery I
L]uw
O#LG$Y
n*
(querySentence); pRWEBd1U
count = ((Integer)query.iterate().next $mdmuUIy-3
O'm><a>8
()).intValue(); 7=i8$v&GX
return count; ,I6jfXI4
} M8dv
y!D
uu ahR
/* (non-Javadoc) jr[(g:L
* @see com.adt.dao.UserDAO#getUserByPage )[fjZG[
[Jv0^"]
(org.flyware.util.page.Page) "yaz!?O>
*/ '!eg9}<
publicList getUserByPage(Page page)throws !"1}zeve
Y-!~x0-H
HibernateException { KYE)#<V}@
String querySentence = "FROM user in class 1 aWzd[i
rPhx^
QKH2
com.adt.po.User"; PD #9Z=Hj
Query query = getSession().createQuery Dl=9<:6FW
=og>& K
(querySentence); 8T6LD
query.setFirstResult(page.getBeginIndex()) ^*sDJ #
.setMaxResults(page.getEveryPage()); 9
5bi
W
return query.list(); b-?wJSf|
} F.{{gpI
$HgBzZ7A2
} x}\x3U
I(^pIe-
{1?94rz
e&~vO| 3w%
LGnb"ZN
至此,一个完整的分页程序完成。前台的只需要调用 )/HbmtX qI
n/W@H Im#
userManager.listUser(page)即可得到一个Page对象和结果集对象 [|iWLPO1&k
+85#`{ D
的综合体,而传入的参数page对象则可以由前台传入,如果用 y7CC5S?
5k:SD7^b
webwork,甚至可以直接在配置文件中指定。 CD^C}MB
yS#)F.
下面给出一个webwork调用示例: I0iTa99K
java代码: LR:PSgy
-M]B;[^
$Lj~ge3#
/*Created on 2005-6-17*/ >+,w2m@0
package com.adt.action.user; uqz HS>GM
?'_Ty`vT
import java.util.List; Cws;6i*=@
OaTnQ|*
import org.apache.commons.logging.Log; G5WQTMzf&
import org.apache.commons.logging.LogFactory; d]A.=NAc
import org.flyware.util.page.Page; 8^IV`P~2M
u<L<o2
import com.adt.bo.Result; Sg%h}]~
import com.adt.service.UserService; wnioIpRkh
import com.opensymphony.xwork.Action; j1zrjhXI
aE|'%72g
/** /esdtH$=
* @author Joa ( p(/
*/ v~8CpC
publicclass ListUser implementsAction{ 8F>u6Y[P
(Q5rOrA"
privatestaticfinal Log logger = LogFactory.getLog R*[X. H
9Lus,l\
(ListUser.class); :g%hT$,]3b
N5PW]
private UserService userService; -L-#-dK'
Ky0}phGRu
private Page page; 2xLEB&
3Pu8IXW
privateList users; # &,W x
1NAGGr00
/* Fqt,VED
* (non-Javadoc) jJY{np
* w"`Zf7a{/
* @see com.opensymphony.xwork.Action#execute() Z8Iqgz7|y
*/ }_/]f!]
publicString execute()throwsException{ xzi_u.iOP
Result result = userService.listUser(page);
=oE(ur
page = result.getPage(); ~<N9ckK
users = result.getContent(); = K)[3mXX
return SUCCESS; _:N=
} eOoqH$
i
i)iK0g"2
/** vAh'6Ob7r
* @return Returns the page. mjQZ"h0
*/ 3S 5`I9I
public Page getPage(){ ! k[JP+;
return page; *{_N*p\{
} Pz^C3h$5_
b(IZ:ekZ5
/** M zFFWk
* @return Returns the users. nt&"?
/s
*/ 1[yy/v'q
publicList getUsers(){ 4wMZNa<Sx
return users; y
Nc@K|
} ?gsPHP US
j.&Y'C7GOC
/** o%b6"_~%3
* @param page /7 8zs-
* The page to set. ;J@U){R
*/ XS}-@5TI
publicvoid setPage(Page page){ 4U8N7
this.page = page; )x,/+R]{8l
} 2tb+3K1
u`.3\Geh
/** E<ILZpP
* @param users A`--*$ 8\
* The users to set. Kv9$c(~#
*/ upLjkQ)_
publicvoid setUsers(List users){ BTzBT%mP
this.users = users; 1{ H=The
} b'ZzDYN
O$n W
/** /F$E)qN7n
* @param userService <~*[OwN
* The userService to set. hj=qWGRgI
*/ f\rE{%
publicvoid setUserService(UserService userService){ ?n]adS{
this.userService = userService; k:&vW21E
} yq?\.~ax
} Q>q-6/|UX
}[{9u#@#
O14\_eAu6
A<]
$[2qPj
?y]R /?
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, VbDk44X.W
~?4BP%g-y
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 AdpJ4}|0
Hd\.,2a"
么只需要: f}~=C2R1<!
java代码: Q#X'.](1
<O1os"w
V|hwT^h
<?xml version="1.0"?> cyLl,OA
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork .VR~[aD
;PB_@Zg
1.0//EN" "http://www.opensymphony.com/xwork/xwork- K5rra%a-7
P5H_iH
1.0.dtd"> ]HaX.Z<
<-mhz`^
<xwork> J)^F
0~z`>#W,
<package name="user" extends="webwork- d-C%R9
;[79Ewd#$
interceptors"> -dWg1`;
diNAT`|?#
<!-- The default interceptor stack name op@=0d??
g${JdxR:
--> bSz@@s.
<default-interceptor-ref @tJ4^<`P{
')}itS8
name="myDefaultWebStack"/> {+ Ibi{
0~EGrEt
<action name="listUser" s3T7M:DM4
/N({"G'
class="com.adt.action.user.ListUser"> ySB0"bl
<param ie11syhV"
@U4hq7xzV2
name="page.everyPage">10</param> l[]cUE
<result )"?eug}D
d&+0JI<
name="success">/user/user_list.jsp</result> Ud Vf/PGx
</action> [!>9K}z,=
f ~*7hv\
</package> W
mbIz[un
'=O1n H<
</xwork> 8{]nS8i
+~BP~
7x=4P|(\}
@)x*6 2r+
>gs_Bzy]
^Zp
这样就可以通过配置文件和OGNL的共同作用来对page对象设置初值 5]GgjQ
Zwz co
了。并可以通过随意修改配置文件来修改每页需要显示的记录数。 x N7sFSV@
i6A9|G$H
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 eM
5#L,Y{
z@J>A![m
2X[oge0@
eX>*}pI
Gov.;hy
我写的一个用于分页的类,用了泛型了,hoho ByuBZ!m
&XdTY +
java代码: Q-!gO
REgM
j>e RV ol
package com.intokr.util; g1?9ge1
SB08-G2
import java.util.List; o<iU;15
1<fW .Q)
/** P;@j
* 用于分页的类<br> G@`ZDn
* 可以用于传递查询的结果也可以用于传送查询的参数<br> )[cuYH>
* rQ_]%ies8
* @version 0.01 \EU^`o+
* @author cheng \@yJbhk
*/ /M::x+/T
public class Paginator<E> { w[\rS`J
privateint count = 0; // 总记录数 #Q)r6V:
privateint p = 1; // 页编号 |:&O!36
privateint num = 20; // 每页的记录数 y.I&x#(^
privateList<E> results = null; // 结果 :s&dn%5N"
V@T(%6<|
/** v-SXPL]_^
* 结果总数 f>$RR_
*/ fN&uat