Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 /P@%{y
I/tMFg
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 rkR5>S( 2M
5Y^"&h[/
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 Znb7OF^#"
jw=PeT|
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 p__wBUB
Y2QX<
。 CA0XcLiFt
[ ,Go*r
分页支持类: >*h+N?
m
$~.YB\3
java代码: wxo
i cTpx#|=
N$]er'`
package com.javaeye.common.util; uB.kkkGZ M
H,L{N'[Xph
import java.util.List; 4($"4>BA
8i`>],,ch
publicclass PaginationSupport { ?$109wZ:9
lUs$I{2_
publicfinalstaticint PAGESIZE = 30; -C
q;
\6SjJ]o>
privateint pageSize = PAGESIZE; &}k7iaO
c]ARgrH-
privateList items; l(sVnhL6h
- /\qGI
privateint totalCount; O+=%Mz(l
f(m,!
privateint[] indexes = newint[0]; $C\ETQ@
E@ U]k$M
privateint startIndex = 0; }<A.zwB<i
8-nf4=ll
public PaginationSupport(List items, int D:/ n2_
=9a2+ v0
totalCount){ b/z-W`gw
setPageSize(PAGESIZE); ( *+'k1Ea
setTotalCount(totalCount); /=/Ki%hh
setItems(items); f*XCWr
setStartIndex(0); R}=5:)%w
} ?ZRF]\dP]
p5fr}#en
public PaginationSupport(List items, int :'Qiwf&
`sYFQ+D#O
totalCount, int startIndex){ +Ua|0>?
setPageSize(PAGESIZE); F$?Ab\#B
setTotalCount(totalCount); ;yt6Yp.6e
setItems(items); ?N<My&E
setStartIndex(startIndex); ;9T}h2^`B
} Q[j| 2U
h$l/wn
public PaginationSupport(List items, int }%jF!d
R#d~a;j
totalCount, int pageSize, int startIndex){ Zok{ndO@|f
setPageSize(pageSize); /YvXyi>^"%
setTotalCount(totalCount); Z;.-UXat
setItems(items); X=$Jp.
setStartIndex(startIndex); _AX9Mu]
} 'V:Q :
/88s~=
publicList getItems(){ 6^"QABc
return items; w==BSH[
} 4!Js="
%hnBpz
publicvoid setItems(List items){ r<+C,h;aww
this.items = items; k5S;G"iJ
} AatSN@,~z
[MTd<@
publicint getPageSize(){ !LN8=u.
return pageSize; tUv>1)
[
} wX"hUu
i?6&4
publicvoid setPageSize(int pageSize){ G68KoM
this.pageSize = pageSize; !,Uo{@E)Y
} m+Ye`]
+FTc/r
publicint getTotalCount(){ "Lbsq\W>
return totalCount; q3$8"Q^
} [A-_?#cZ
Nn. 9J
publicvoid setTotalCount(int totalCount){ 5CkG^9
if(totalCount > 0){ K~
eak\=
this.totalCount = totalCount; D|LO!,=b
int count = totalCount / y7,fFUKl
p&<Ssc
pageSize; U6]#RxH
if(totalCount % pageSize > 0) buGBqx[
count++; Ia&*JYM[
indexes = newint[count]; n$/|r
for(int i = 0; i < count; i++){ F(G..XJQ
indexes = pageSize * 0WUBj:@g
'$tCAS
i; Ww]$zd-bo
} g&Vhu8kNIA
}else{ AWR :~{
this.totalCount = 0; YJJ1N/Z1
} cbzA`b'Mg
} N"S`9B1eD(
pi"H?EHk
publicint[] getIndexes(){ ,-pE/3|(
return indexes; uBm"Xkxe|w
} |#TU"$;
@?,x3\N-
publicvoid setIndexes(int[] indexes){ 8 1,N92T5
this.indexes = indexes; ZoG@"vr2
} 9c>i>Vja!
hg)Xr5>
publicint getStartIndex(){ 9z7_D_yN2
return startIndex; >ED;_L*_o
} sf>
E
>G]JwO
publicvoid setStartIndex(int startIndex){ Ebnb-Lze,
if(totalCount <= 0) 7H6Ts8^S
this.startIndex = 0; 0j$\k|xFXZ
elseif(startIndex >= totalCount) yZleots1
this.startIndex = indexes e=sc$1|4=
n1-p/a.
[indexes.length - 1]; 2f,8Jnia
elseif(startIndex < 0) ='7m$,{(Q[
this.startIndex = 0; -$d?e%}#
else{ c#OxI*,+/
this.startIndex = indexes ? x%s
j
b;i*}4h!
[startIndex / pageSize]; jBLTEb
} 22l'kvo4"
} !dqC6a
x5lVb$!G
publicint getNextIndex(){ Fy=GU<&AI
int nextIndex = getStartIndex() + EmNVQ1w
Za|7gt];l
pageSize; q*hn5 K*
if(nextIndex >= totalCount) m06'T2 I
return getStartIndex(); .n 9.y8C
else V._-iw]v
return nextIndex; 9[eiN
} $@AJg
GkAd"<B
publicint getPreviousIndex(){ -X.#Y6(
int previousIndex = getStartIndex() - ~;"eNg{T
(}A$4?
pageSize; k[Em~>m
if(previousIndex < 0) ` H'G"V
return0; TFSdb\g
else #7uH>\r
return previousIndex;
+25}X{r$_
} #VQZ"7nI@
VfnL-bDGV
} >.?yz
r_7%|T8
vXJs.)D7
!wYN",R-
抽象业务类 OM EwGr(
java代码: pH' Tx>
^twyy9VR
^ D0"m>3r
/** yFE0a"0y
* Created on 2005-7-12 </I%VHP,[f
*/ > X~\(|EM
package com.javaeye.common.business; uLdHE5vr
5wK==hZ
import java.io.Serializable; vl (``5{
import java.util.List; 1g;2e##)
Kw fd
S(
import org.hibernate.Criteria; <J8c dB!e
import org.hibernate.HibernateException; ?eJ' $
import org.hibernate.Session; *bK=<{d1P
import org.hibernate.criterion.DetachedCriteria; Y>$5j}K
import org.hibernate.criterion.Projections; e~vO
import <&eJIz=
`,O7S9]R+
org.springframework.orm.hibernate3.HibernateCallback; @&*TGU
import %Wtf24'o;v
=ejcP&-V/
org.springframework.orm.hibernate3.support.HibernateDaoS |~9jO/&r
eaRa+ <#u
upport; HNZ$CaJh
XpAJP++
import com.javaeye.common.util.PaginationSupport; z_c-1iXCW
_`2%)#^o
public abstract class AbstractManager extends MWwqon|
X}#vt?mu
HibernateDaoSupport { G4
7^xR
w,1N ;R&
privateboolean cacheQueries = false; 9SC1A -nF
d V%o:@Z
privateString queryCacheRegion; XfcYcN
AbNr]w&pXC
publicvoid setCacheQueries(boolean -x?Z2EA!
$1=7^v[U
cacheQueries){ JuJW]E Q
this.cacheQueries = cacheQueries; Uw4iWcC
} BA
a:!p
=eA|gt
publicvoid setQueryCacheRegion(String yzEyOz@Q
UP#@gxF
queryCacheRegion){ *zRig|k !H
this.queryCacheRegion = shw?_#?1dy
^!tX+`,6^
queryCacheRegion; 9Qyc!s`
} N[@~q~v
*)[fGxz
\
publicvoid save(finalObject entity){ bUgg2iFS
getHibernateTemplate().save(entity); w5Fk#zJv
} 5c5!\g~'
QMMpB{FZ`o
publicvoid persist(finalObject entity){ qkfof{z
getHibernateTemplate().save(entity); smCACQ$(
} gj;gl
="3
F-kjv\
publicvoid update(finalObject entity){ j+!u=E
getHibernateTemplate().update(entity); '@t,G,FJ
} w/NT 5
_;}$/
publicvoid delete(finalObject entity){ kQI'kL8>
getHibernateTemplate().delete(entity); %@QxU-k_
} QFTiE1mGH
iv`G}.Bo
publicObject load(finalClass entity, }w)}=WmD
gLMb,buqC
finalSerializable id){ WX Fm'5Vr
return getHibernateTemplate().load W~H`{x%Av>
1n8y4k)
(entity, id); /J}G{Y
|n
} $2FU<w$5
U*nB=
=
publicObject get(finalClass entity, wQW`Er3w
.i\FK@2
finalSerializable id){ ;)ay uS sQ
return getHibernateTemplate().get H[w';u[%
dpz@T>MS=
(entity, id); FqyxvL.
} ,{IDf
:X":>M;;+
publicList findAll(finalClass entity){ e# Y{YtE
return getHibernateTemplate().find("from (6c/)MH
3ZT3I1/D
" + entity.getName()); e=XP4h
} [(
xPX
\=({T_j4
publicList findByNamedQuery(finalString uou
"s9
Z7wl~Hk
namedQuery){ rFcz0
return getHibernateTemplate ~xzr8 P
b!t[PShw^
().findByNamedQuery(namedQuery); #2|biTJ
} 3]S_w[Q4
/ 8O=3
publicList findByNamedQuery(finalString query, )h ,v(Rxa
OGEe8Z9Jt
finalObject parameter){ <uU<qO;6
return getHibernateTemplate @nqM#
[<r.M<3
().findByNamedQuery(query, parameter); b4:{PD~Mh
} K1YxF
]U@~vA#''
publicList findByNamedQuery(finalString query, jhRr!
_G)A$6weU
finalObject[] parameters){ ;Q3[} ]su
return getHibernateTemplate 62;xK-U
nK< v
().findByNamedQuery(query, parameters); (e_<~+E
} = ~s+<9c]
UNSXr`9
publicList find(finalString query){ C}9GrIi
return getHibernateTemplate().find Z|KDi
`S
Lapeh>1T
(query); -[N9"Z,
} U8aVI
/IcGJ&;
publicList find(finalString query, finalObject @?s>oSyV
?9?A)?O<j~
parameter){ 7oZ Pb
return getHibernateTemplate().find /7#MJH5b6
:}36;n<['
(query, parameter); {1=|H$wKg
} %4`
U' j
O\uIIuy
public PaginationSupport findPageByCriteria tvno3"
3AENY@*
(final DetachedCriteria detachedCriteria){ )cL(()N
return findPageByCriteria C@;e<
qu#xc0?
(detachedCriteria, PaginationSupport.PAGESIZE, 0); m*1
} {a\! 1~
R68:=E4
public PaginationSupport findPageByCriteria W3ms8=z
s;Bh69
(final DetachedCriteria detachedCriteria, finalint ]' n4e*
YeT{<9p
startIndex){ K%`]HW@I{
return findPageByCriteria C ]B P}MY<
qh W]Wd"g
(detachedCriteria, PaginationSupport.PAGESIZE, \{Q_\s&)
yQ^, >eh
startIndex); QiA}0q3]0
} D
HQxu4
c?<)!9:
public PaginationSupport findPageByCriteria tKyGD|g S
IlO,Ql
(final DetachedCriteria detachedCriteria, finalint 6jm?d"9
2aR9vmR
pageSize, 67/\0mV:~
finalint startIndex){ xC5Pv">
return(PaginationSupport) (!b)<V*
!\VEUF,K?
getHibernateTemplate().execute(new HibernateCallback(){ s%rmfIp"
publicObject doInHibernate MrUjqv6a[
=!DX,S7
(Session session)throws HibernateException { [So1`IA6
Criteria criteria = n>,GmCo
Yx,E5}-
detachedCriteria.getExecutableCriteria(session); _'G'>X>}WU
int totalCount = G3y8M|:
]7TOA$Q
((Integer) criteria.setProjection(Projections.rowCount UsA fZg8
E ,ilJl\
()).uniqueResult()).intValue(); 5|jY
criteria.setProjection t%e<]2-8
]Hl{(v\HO
(null); :B=Gb8?
List items = ^B%ki
'y>Y */
criteria.setFirstResult(startIndex).setMaxResults y:Gn58\o
SHSfe{n
(pageSize).list(); bxwwYSS
PaginationSupport ps = z}==6|{
aso8,mpZuA
new PaginationSupport(items, totalCount, pageSize, 6DU(KYN
%=*|:v
startIndex); ?vbAaRg50s
return ps; WZHw(BN{+
} ,?jc0L.'r]
}, true); wjH1Ombt
} +-),E.
Odw'Ua
public List findAllByCriteria(final Wj!+
E{y<r
*pD|N
DetachedCriteria detachedCriteria){ $8(QBZq
return(List) getHibernateTemplate a_0I)'
?
w2s06`g
().execute(new HibernateCallback(){ u^MRKLn
publicObject doInHibernate 0#=xUk#LP`
dg~lz8 0
(Session session)throws HibernateException { WC=d@d)M
Criteria criteria = Vh;|qF 9
~uq010lMno
detachedCriteria.getExecutableCriteria(session); `YwJ.E
return criteria.list(); yEjiMtQll]
} \p.yR.
}, true); rZ n@i
} F_-xp1|
8oI|Z=
public int getCountByCriteria(final /;}%E
JvvN>bg
DetachedCriteria detachedCriteria){ j[R.UB3J
Integer count = (Integer) S[7^#O.)
v,*C>u\3s
getHibernateTemplate().execute(new HibernateCallback(){ g5pFr=NV
publicObject doInHibernate jTg~]PQ^
5_](N$$
(Session session)throws HibernateException { =NY55t.
Criteria criteria = \1<|X].jNY
M?My+o T
detachedCriteria.getExecutableCriteria(session); 2z#S|$
return cNwHY
Z'
~@6l7H6{
criteria.setProjection(Projections.rowCount opm_|0
jDQ ?b\^
()).uniqueResult(); -G/qfd|s/
} Fx.Ly]L
}, true); t_!p({
return count.intValue(); `C|];mf(#
} <FU?^*~
} o9sPyY$aQ
{K"hlu[
VJTO:}Q
:] U\{;q2
,YvOk|@R
/i27F2NQm
用户在web层构造查询条件detachedCriteria,和可选的 Nc4;2~XwRp
h/|p`MP\1
startIndex,调用业务bean的相应findByCriteria方法,返回一个 Pf,@U'f|
A-uIZ
zC
PaginationSupport的实例ps。 LWTPNp:"{w
z7AWWr=H
ps.getItems()得到已分页好的结果集 flC%<V%'-
ps.getIndexes()得到分页索引的数组 =&pLlG
ps.getTotalCount()得到总结果数 6hd<ys?
ps.getStartIndex()当前分页索引 `#l3a
ps.getNextIndex()下一页索引 (57!{[J
ps.getPreviousIndex()上一页索引 [|c%<|d2
"OwVCym?
IaSpF<&Y;
2'- "&d+O
d,l?{Ln
*5k40?w
]OdZlZBsJ
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 4c(Em+4
I-g/)2
,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 $F#
5/gDVQ
7mdd}L^h
Z
一下代码重构了。 K.mxF,H
yj_> G
我把原本我的做法也提供出来供大家讨论吧: 6*>Lud
@j}%{Km]Y
首先,为了实现分页查询,我封装了一个Page类: m#8PX$_
java代码: ]7K2S{/o{
LOi}\O8
wxc#)W
/*Created on 2005-4-14*/ I-r+1gty
package org.flyware.util.page; wz69Yw7
OrM1eP"I
/** 54z.@BJhE
* @author Joa njX$?V
* r)}U
'iv*%
*/ T#3@r0M
publicclass Page { 0&]1s
zM=MFKhi ~
/** imply if the page has previous page */ D 6y,Q
privateboolean hasPrePage; jci,]*X4
hF0,{v
/** imply if the page has next page */ YVDFcN9v
privateboolean hasNextPage; >god++,o
;TWLo_
/** the number of every page */ 3rKJ<(-2/
privateint everyPage; ]'(D*4
n:`f.jG |
/** the total page number */ [C0v-
privateint totalPage; 7LVG0A2>7
<OGG(dI
/** the number of current page */ 9)'f)60^
privateint currentPage; lh"*$.j-
c'eZ-\d{
/** the begin index of the records by the current 6u+aP
I6f/+;E
query */ b),fz
privateint beginIndex; 3*=0`}jMJ
aU_Hl+;
LO{Axf%
/** The default constructor */ PZusYeV8b
public Page(){ *l+Dbm,u
+ tMf&BZ
} \$wkr
P7.bn
/** construct the page by everyPage &R%'s1]o
* @param everyPage W/ Q*NB
* */ byM-$l
public Page(int everyPage){ 6qH0]7m aI
this.everyPage = everyPage; 'q)g,2B%
} DaQl ip
@GFB{ ;=
/** The whole constructor */ Y"MHs0O5>
public Page(boolean hasPrePage, boolean hasNextPage, l,4O
~x9]?T
zd=O;T;.
int everyPage, int totalPage, ?qaWt/m
int currentPage, int beginIndex){ >SK:b/i
this.hasPrePage = hasPrePage; (6S'wb
this.hasNextPage = hasNextPage; \uJRjw+
this.everyPage = everyPage; Q# B0JT1
this.totalPage = totalPage; zOs}v{8"
this.currentPage = currentPage; k9;^|Cm
k
this.beginIndex = beginIndex; D=#RQ-
} r\;fyeH
cl%+m
/** <:}nd:l1
* @return sF{aG6u
* Returns the beginIndex. 5 aA*
~\
*/ -[=eVS.2%
publicint getBeginIndex(){ kUf i
return beginIndex; !5o j~H
} "0An'7'm
Dw%'u'HG
/** T+<.KvO-
* @param beginIndex RRIh;HhX
* The beginIndex to set. x=oV!x
*/ Tnp
P '
publicvoid setBeginIndex(int beginIndex){ V\;Xa0
this.beginIndex = beginIndex; cq4~(PXTg
} <&3P\aM>
U)/.wa>
/** =&bI-
* @return y7,I10:D
* Returns the currentPage. C`[<6>&y
*/ fST.p|b7
publicint getCurrentPage(){ [IL*}M!
return currentPage; bv[#|^/
} QqA=QTZ}
94"+l@K
/** 7Y5 r3a}%
* @param currentPage SYCL\b
* The currentPage to set. D=0YLQ*rP
*/ 7~Y\qJ4b
publicvoid setCurrentPage(int currentPage){ >JyS@j}
this.currentPage = currentPage; )+G"57p
} }L\;W:0
ytZ o0pad
/** mmTpF]t
?`
* @return 'Gy`e-yB
* Returns the everyPage. 6"Uu;Q
*/ 1q6)R/P
publicint getEveryPage(){ x-BU$bx5
return everyPage; XO+BZB`F
} >,e^}K}C
v e&d"8+]
/** $.PRav
* @param everyPage 8q^}AT<C
* The everyPage to set. xfYKUOp/
*/ m2PUU/8B/
publicvoid setEveryPage(int everyPage){ my (@~'
this.everyPage = everyPage; ?qgQ)#6
} =zkN63S
|[SHpcq>
/** Q5,zs_j
* @return W$4$%r8
* Returns the hasNextPage. TeHJj`rdAU
*/ ,aP6ct
publicboolean getHasNextPage(){ Ku(YTXtK
return hasNextPage; {9@D zP
} 8y
LcTA$T
`3;EJDEdbi
/** k@4N7}
* @param hasNextPage ~; 9HGtg
* The hasNextPage to set. n7[nl43
*/ IMf|/a9-
publicvoid setHasNextPage(boolean hasNextPage){ CTIS}_CWd=
this.hasNextPage = hasNextPage; FM{f{2j
} $ L*gtZ
q0.!T0i
/** IZZAR
* @return ^'`b\$km-0
* Returns the hasPrePage. )|~K&qn`
*/ x~e._k=
publicboolean getHasPrePage(){ 5X{|*?>T
return hasPrePage; *u},(4Qf
} ]
K$YtM^
7^eyO&4z
/** JipNI8\r
* @param hasPrePage %3z[;&*3O
* The hasPrePage to set. j~q 7v
`":
*/ y=Y k$:-y
publicvoid setHasPrePage(boolean hasPrePage){ Zxebv#4
this.hasPrePage = hasPrePage; .n8R%|C5
} (xfc_h*xA
*:%&z?<Fw
/** 7HPwlS
* @return Returns the totalPage. jSI1tW8
* wHLQfrl0
*/ E7X6RB b
publicint getTotalPage(){ odhcD;^X1
return totalPage; q/s-".%P
} K=gg <E<
XZE(& (s
/** G5}_NS/
* @param totalPage b}!
cEJY
* The totalPage to set. "wcaJ;Os
*/ +~8Lc'0aA
publicvoid setTotalPage(int totalPage){ vk7IqlEQ
this.totalPage = totalPage; K[T0);hZR
} VVJ0?G
(?
j7}mh
} ,=)DykP
zluq2r
\BHZRytQF
,rB(WKU
/YJo"\7
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 01.q9AGy
;Q{D]4
个PageUtil,负责对Page对象进行构造: a\P :jgF
java代码: +XWTu!
?_eLrz4>L^
FB6Lz5:Vf
/*Created on 2005-4-14*/ <*5S7)]BP
package org.flyware.util.page; wB)y@w4k
;[y( 14g
import org.apache.commons.logging.Log;
+SFFwjI
import org.apache.commons.logging.LogFactory; k4{!h?h
Ej(BE@6>s
/** ZqclmCi
* @author Joa SeHrj&5U
* 72l:[5ccR
*/ aL(G0@(
publicclass PageUtil { j4XVk@'OX
ka_m
Q<{9
privatestaticfinal Log logger = LogFactory.getLog P^te
f ,e]jw@
(PageUtil.class); vHi%UaD-y
]
(e ,J
/** utck{]P
* Use the origin page to create a new page tA1?8`bQ
* @param page bB<S4@jF8z
* @param totalRecords c7CYulm
* @return .gO|=E"
*/ J!Z6$VERy
publicstatic Page createPage(Page page, int F_079~bJ
=z. hJu
totalRecords){ ,!Wo6{'
return createPage(page.getEveryPage(), %{
BV+&
h1~h&F?
page.getCurrentPage(), totalRecords); S)hDsf.I
} aen%
AZ.QQ*GZ#y
/** d9[j4q_
* the basic page utils not including exception YP,,vcut
a;[\ nCK
handler L2@:?WW[
* @param everyPage gP>pbW_
* @param currentPage C@a I*+@-"
* @param totalRecords Ou[`)|>
* @return page &$s:h5HoX
*/ lw3H
8[
publicstatic Page createPage(int everyPage, int zY/Oh9`=v
xd{.\!q.
currentPage, int totalRecords){ i$kB6B#==
everyPage = getEveryPage(everyPage); n
n F
currentPage = getCurrentPage(currentPage); 6%V:Z
int beginIndex = getBeginIndex(everyPage, 0(i3RPIj\
_i>_S n1"
currentPage); `,4yGgD!4
int totalPage = getTotalPage(everyPage, q{h,}[U=
nc1~5eo
totalRecords); <VZ43I
boolean hasNextPage = hasNextPage(currentPage, 0[UI'2
g;Ugr8
totalPage); / /NV_^$y
boolean hasPrePage = hasPrePage(currentPage); k
(AE%eA
N[eLQe]q
returnnew Page(hasPrePage, hasNextPage, T.cTL.}
everyPage, totalPage, FWu:5fBZY
currentPage, Sfe[z=7S
$7YZ;=~B
beginIndex); g#(+:^3'
} '/`O*KD]
@vq)Y2)r\
privatestaticint getEveryPage(int everyPage){ T;DKDga
return everyPage == 0 ? 10 : everyPage; XW aa`q
} u^xnOVE
UG\2wH_
privatestaticint getCurrentPage(int currentPage){ @95p [
return currentPage == 0 ? 1 : currentPage; J4eU6W+ {
} KKpM=MZ
qG,h
1
privatestaticint getBeginIndex(int everyPage, int zuNm!$
kb 74:
currentPage){ 7=G6ao7
return(currentPage - 1) * everyPage; g@ J F
} <yl@!-'J7
OGcdv{,P
privatestaticint getTotalPage(int everyPage, int qGq]E`O
8b0j rt
totalRecords){ L:C/PnIV
int totalPage = 0; 50 w$PW
qt.4dTd:_
if(totalRecords % everyPage == 0) cEf"m?w
totalPage = totalRecords / everyPage; qJF'KHyU{l
else wdj?T`4
totalPage = totalRecords / everyPage + 1 ; <e#v9=}DI
Q@}SR%p
return totalPage; )xf(4
} 2MB>NM<xO
ajkV"~w',|
privatestaticboolean hasPrePage(int currentPage){ 'T^MaLK
return currentPage == 1 ? false : true; [? "hmSJ
} !Gnm<|.
$m
;p@#n
privatestaticboolean hasNextPage(int currentPage, l`~$cK!
t>quY$}4
int totalPage){ 41/civX>V
return currentPage == totalPage || totalPage == YKUAI+ks
g@x72$j
0 ? false : true; V}TPt6C2
} Ur 1k3
^jL44?W}l
,Gy,bcv{
} ts&\JbL
8p829
NI"Zocp
o~Hq&C"^}
(]sm9PO
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。 uxdB}H,
E`LaO
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 8oUR/___
De3;}]wC
做法如下: c|:EMYS
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 aNM*=y`
Q0`@=5?-
的信息,和一个结果集List: +)h# !/
java代码: zEQQ4)mA
xBc$qjV
2.JrLBhN
/*Created on 2005-6-13*/ %o/@0.w
package com.adt.bo; _!|$ i
t{UWb~"
import java.util.List; 2@T0QJ
RF8,qz
import org.flyware.util.page.Page; 8aQTm-{m
f-^*p
/** Uf_mwEE
* @author Joa 7#"y mE
*/ Z}zka<y6K6
publicclass Result { D]d! lMK/
OWz{WV.
private Page page; p\I3 fI0i
U(+QrC:
private List content; ph)=:*A6&
!1S!)#
/** Y#): 1C1
* The default constructor
})!-
*/ 6(\-aH'Ol
public Result(){ BGfwgI.m
super(); ~Gc@#Msj
} Y:CqQ
o ;9H~E
/** dC4`xUv
* The constructor using fields 3#""`]9H
* P5dD&
* @param page ve a$G~[%6
* @param content ,]qc#KDq-1
*/ ?l[#d7IB
public Result(Page page, List content){ [$$R>ELYQ
this.page = page; 6_8y Q
this.content = content; N1E9w:T`
} i< imE#
/QlzWson
/** {?w*n_T.
* @return Returns the content. Ac*)z#H
*/ Grw[h
publicList getContent(){ 2fayQY
xD
return content; ^eoW+OxH
} R/B/|x
}#g &l*P
/** #mM9^LJ
* @return Returns the page. ho#<?rh_
*/ rWJRoGk/
public Page getPage(){ yq2AZ@}"
return page; we}5'bS>
} CyVi{"aF3
hYFi"ck
/** =JTwH>fD
* @param content !#5y%Bf
* The content to set. )g&nI<Mh
*/ u,@ac[!vP
public void setContent(List content){ va(6?"9
this.content = content; $^e_4]k
} *c.w:DkfB
/gaC
/** o{2B^@+Vb
* @param page x
`%x f
* The page to set. ^}gZ+!kA
*/ :1UOT'_
publicvoid setPage(Page page){ K^/.v<w
this.page = page; otdv;xI9
} ykx13|iR
} KLj/,ehD
!
I_Gm2Dd
q|lP?-j
dn%'bt
8SiWAOQAL
2. 编写业务逻辑接口,并实现它(UserManager, frQ=BV5%6
EN>a^B+!
UserManagerImpl) 4dz Ym+vJm
java代码: (:+Wc^0
m*e8j[w#
qIy9{LF
/*Created on 2005-7-15*/ ] RVme^=
package com.adt.service; *=%`f=
/byF:iYI
import net.sf.hibernate.HibernateException; 'oBv(H
Cb|R
import org.flyware.util.page.Page; 'o8,XBv-
ARJtE@s6Y
import com.adt.bo.Result; +,ld;NM{
ye
{y[$#3
/** :W'.SRD
* @author Joa JV;VR9-l
*/ : T4ap_Ycq
publicinterface UserManager { p8CaD4bE
3=Xvl 58k
public Result listUser(Page page)throws xnZ
EL
*l5!Iu
HibernateException; MA 6uJT
{!4ZRNy(k
} t/]za4w/
Z 2uU'T
Hw#yw g
Yk7^?W
=lh&oPc1
java代码: JS >"j d#
~W gO{@Mw
(elkk#
/*Created on 2005-7-15*/ {X\FS
package com.adt.service.impl; |z)7XK
O4W2X@
import java.util.List; XQ Si
X=k|SayE8
import net.sf.hibernate.HibernateException; X*r?@uK5
/5XdZu6k`h
import org.flyware.util.page.Page; ]V"B`ip[2
import org.flyware.util.page.PageUtil; U`4t4CHA
Bo*Wm
w
import com.adt.bo.Result; *u34~v16,
import com.adt.dao.UserDAO; 4Gh%PUV#
import com.adt.exception.ObjectNotFoundException; !NhVPb,
import com.adt.service.UserManager; @jr$4pM?
2$ \#BG
/** (>om.FM
* @author Joa Nm0|U.<
*/ cl'qw##
publicclass UserManagerImpl implements UserManager { 0te[i*G
$O9#4A;
private UserDAO userDAO; fqm6Pd{:(
`7
J4h9K
/** pWGIA6&v(
* @param userDAO The userDAO to set. WZ@$bf}f0
*/ ][T>052v
publicvoid setUserDAO(UserDAO userDAO){ q[.,i{2R}
this.userDAO = userDAO; =co6.Il
} 38RyUHL=
Or()AzwE@
/* (non-Javadoc) kPp7;U2A
* @see com.adt.service.UserManager#listUser 8rjiW#
gM
v0[~;u
(org.flyware.util.page.Page) p:4oA<V
*/ \//{\d
public Result listUser(Page page)throws Znh<r[p<
#|} EPD9$
HibernateException, ObjectNotFoundException { PkdL] !:
int totalRecords = userDAO.getUserCount(); Kx,<-]4
if(totalRecords == 0) RM`iOV,Y
throw new ObjectNotFoundException bO gVCg
0 !F!Y_
("userNotExist"); OmECvL'Z
page = PageUtil.createPage(page, totalRecords); n\4sNoFI
List users = userDAO.getUserByPage(page); xNxSgvco,
returnnew Result(page, users); -sk!XWW+
} #Ic-?2Gn4<
~w$ ^`e!]
} U#n1N7P|$F
@yn1#E,
;U<rFs40
Qnv)\M1
nA#dXckoc
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 :\G`}_db'
xR5zm%\
询,接下来编写UserDAO的代码: G+Zm
3. UserDAO 和 UserDAOImpl: k!wEPi]
java代码: y$HV;%G{26
Bjsg!^X7
\w@ "`!%
/*Created on 2005-7-15*/ (,
uW-
package com.adt.dao; >o!~T}J7
mp>Ne6\Tu
import java.util.List; CF@j]I@{
8}!WJ2[R
import org.flyware.util.page.Page; Sa$-Yf
H_ 7E K
import net.sf.hibernate.HibernateException; 'WJ3q|o/
^/$bd4,z
/** kt hy9<!$
* @author Joa +Rd;>s*.Y
*/ -f8iq[F5
publicinterface UserDAO extends BaseDAO { V5HK6- T
' u4TI=[6
publicList getUserByName(String name)throws .d%CD`8!
@7,k0H9Moa
HibernateException; rW0-XLbL5H
|jTRIMj%,_
publicint getUserCount()throws HibernateException; : ]~G9]R`
~myY-nEY
publicList getUserByPage(Page page)throws r/mKuGa]
'C<4{agS
HibernateException; wy4}CG
*TP>)o
} 45tQ$jr`1
j.7BoV
VPXUy=W
X< p KAO\
Y`!Zk$8
java代码: 5TS&NefM
W 33MYw
#w#:f
/*Created on 2005-7-15*/ _tQR3I5
package com.adt.dao.impl; p;9"0rj,z
Bh<6J&<n
import java.util.List;
0ZJt
}w/6"MJ[n
import org.flyware.util.page.Page; 4,qhWe`/
jq12,R2+)
import net.sf.hibernate.HibernateException; JY6^pC}*
import net.sf.hibernate.Query; :c`Gh< u
vAjvW&'g
import com.adt.dao.UserDAO; (E]q>'X
~~X-$rtU
/** i5jsM\1j
* @author Joa 2N[/Cc2Tg/
*/ q2~@z-q)b
public class UserDAOImpl extends BaseDAOHibernateImpl Alpk5o5B
='<789wT
implements UserDAO { QNm8`1
j)b[7%
/* (non-Javadoc) gano>W0
* @see com.adt.dao.UserDAO#getUserByName d\v1R-V
:"I!$_E'
(java.lang.String) yJ?S7+b
*/ q=`i
publicList getUserByName(String name)throws Dt=@OZW
KetNFwbUf
HibernateException { /V$U%0
String querySentence = "FROM user in class 0;2"X[e
Y2Y)| <FH
com.adt.po.User WHERE user.name=:name"; b]k9c1x
Query query = getSession().createQuery M.?[Xpa
B6xM#)
(querySentence); oZ,_ G,b^
query.setParameter("name", name); sA!$}W
return query.list(); 2c1L[]h'
} fm1yZX?`
_mc-CZ
/* (non-Javadoc) ~Y/o9x0
* @see com.adt.dao.UserDAO#getUserCount() 0*yD
*/ cZlDdr%
publicint getUserCount()throws HibernateException { EE$\8Gx']!
int count = 0; *Sp_s_tS
String querySentence = "SELECT count(*) FROM kqQT^6S
Gqs)E"h
user in class com.adt.po.User"; Tqj:C8K{
Query query = getSession().createQuery D,P{ ,/
JK'FJ}Z4
(querySentence); l~Rd\.O
count = ((Integer)query.iterate().next yr/G1?k%ML
S^T
><C
()).intValue(); ]-"G:r
return count; pq$-s7#
} hU6oWm
H<Ik.]m
/* (non-Javadoc) M)1Y7?r]
* @see com.adt.dao.UserDAO#getUserByPage a|eHo%Qt
]+A%37
(org.flyware.util.page.Page) Wmc@:
(n
*/ p(Ux]_s%
publicList getUserByPage(Page page)throws \45F;f_r6
bYAtUEv
HibernateException { .W
s\%S
String querySentence = "FROM user in class w;;9YFBdM
,=V9?
com.adt.po.User"; <NXJ&xs-+
Query query = getSession().createQuery {ep(_1
|wINb~trz
(querySentence); qV79bK
query.setFirstResult(page.getBeginIndex()) y~n1S~5cI
.setMaxResults(page.getEveryPage()); xM)6'= x6
return query.list(); 1V.oR`&2E
} ?"$Rw32
V@rqC[on
} ->L> `<7(
LR#BP}\b'
%%FzBbWAO
D9h
yQ0:M/r;0
至此,一个完整的分页程序完成。前台的只需要调用 G&
m~W
je85G`{DC
userManager.listUser(page)即可得到一个Page对象和结果集对象
s>*xAIx
5Ky(C6E$s
的综合体,而传入的参数page对象则可以由前台传入,如果用 * o{7 a$V
/]oQqZHv
webwork,甚至可以直接在配置文件中指定。 e2^TQv2(=e
% 'OY
下面给出一个webwork调用示例: _Wqy,L;J
java代码: s@IgaF {
_;M3=MTM9
,pIh.sk7s*
/*Created on 2005-6-17*/ /mXxj93UA
package com.adt.action.user; lFl(Sww!\
#/B g5:
import java.util.List; Bmt^*;WY+
iD*L<9
import org.apache.commons.logging.Log; -}_1f[b
import org.apache.commons.logging.LogFactory; $C{,`{=
import org.flyware.util.page.Page; _ee<i8_Va
ly:2XvV3~
import com.adt.bo.Result;
T~L&c
import com.adt.service.UserService; e|N~tUVrrN
import com.opensymphony.xwork.Action; >L')0<!&
+pRNrg?k
/** A `{hKS
* @author Joa }O Y/0p-Z
*/ X,{ 3_
publicclass ListUser implementsAction{ ALj~e#{;z
BP}@E$
privatestaticfinal Log logger = LogFactory.getLog h4#'@%
1mD)G55Ep
(ListUser.class); dci<Rz`h
5th?m>
private UserService userService; [ ou$*
y @S_CB47
private Page page; iX[g
MU%7'J :_
privateList users; v7n@CWnN
F1A40h7R$Y
/* 1ktxG1"1
* (non-Javadoc) $<AaeyR!N
* V';l H2
* @see com.opensymphony.xwork.Action#execute() d6W\
\6V
*/ P ^ 4 @
publicString execute()throwsException{ C;j&Vbf
Result result = userService.listUser(page); stUUez>
page = result.getPage(); &d0sv5&s
users = result.getContent(); 4jt(tZS
return SUCCESS; mRa\ wEg%
} 0<O()NMv
)2_[Ww|.
/** -n8d#Qm)
* @return Returns the page. 9:P]{}
*/ wZs 2aa
public Page getPage(){ qV6WT&)T
return page; hJsP;y:@Lm
} w@<II-9L)<
'%82pZ,?
/** "Kdn`zN{
* @return Returns the users. G;$;$gM
*/ 'qvj[lpGr
publicList getUsers(){ _ OC@J*4.
return users; 7B)1U_L0H
} 2;u
i'B
0EF~Ouef
/** 5dB62dqN
* @param page +FAj30
* The page to set. 3H`{
A/r
*/ Fj(GyPFG
publicvoid setPage(Page page){ 9h?'zyX
B
this.page = page; r*]pL<
} +D:8r|evH
0~z\WSo
/** ?*%_:fB
* @param users ;}j(x;l>t
* The users to set. oFf9KHorW
*/ I{jvUYrKH
publicvoid setUsers(List users){ #
)y/aA
this.users = users; BqY_N8l&E
} KVJ,
a
C!a1.&HHZ7
/** Rh?bBAn8
* @param userService }&t>j[
* The userService to set. YT
Zi[/
*/ \?d3Pn5`
publicvoid setUserService(UserService userService){ dniU{v
this.userService = userService; M{Z
;7n'
} GD{L$#i!
} p.SipQ.P
S k~"-HL|
-g]Rs!w'
8&)v%TX
G$+v |z
上面的代码似乎看不出什么地方设置了page的相关初值,事实上, O,%,dtD[a
DzQBWY]
)
可以通过配置文件来进行配置,例如,我想每页显示10条记录,那 +t+<?M B
\ph.c*c
么只需要: "|L"C+tE
java代码: 2t-w0~O
{O^u^a\m
6(Pan%
<?xml version="1.0"?> e~9O#rQI
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 6:]N%
3KkfQ{
1.0//EN" "http://www.opensymphony.com/xwork/xwork- hTr5Q33y>
.h7s.p?
1.0.dtd"> UJ)pae
X#lNS+&='
<xwork> \ ;npdFy
!Qe;oMqy}
<package name="user" extends="webwork- W]9*dabem
bf"'xn9
interceptors"> d,b4q&^X8
d,V#5l-6
<!-- The default interceptor stack name NQk aW)
5&&4-
--> qd*}d)!
<default-interceptor-ref ~2w&+@dV%
elOeXYO0
name="myDefaultWebStack"/> 3@>F-N
c=oDzAzuV\
<action name="listUser" MzJCiX^
?Z7`TnG$uf
class="com.adt.action.user.ListUser"> QJGGce
<param 5Q?Jm~H9
r]DiB:.
name="page.everyPage">10</param> Gk,Bx1y
<result Ts5)r(
`>g G"1,]
name="success">/user/user_list.jsp</result> 6#?T?!vZ
</action> SS=<\q#MS
>cu%C s=m
</package> KP&+fDa
{ mi}3/
</xwork> SB_Tzp
9y7N}T6
J D\tt-
tE7jTe
m&UP@hUV-
z M9#1^X
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 =)[m[@,c
=q4}(
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。 rFRcK>X\L
Kc MzY
注:上面的<param>的配置,还需要webwork和Spring整合的配合。 9u B?-.
:!`"GaTy
e
w^(3&
[XfR`@
U
v2.Jo/Q
我写的一个用于分页的类,用了泛型了,hoho ?[D3-4
F "@% 7xy
java代码: Kc/1LeAik
rhJ&* 0M
e~o!Qm
package com.intokr.util; AjC:E+g
:t}\%%EbmE
import java.util.List; b\k]Jx
)pB#7aEw
/** P6:9o}K6
* 用于分页的类<br> |Wh3a#
* 可以用于传递查询的结果也可以用于传送查询的参数<br> oaY_6
* RJrz ~,}
* @version 0.01 SK<Rk
* @author cheng n
~t{]if"
*/ qpjY &3SI
public class Paginator<E> { 1Ms[$$b$
privateint count = 0; // 总记录数
*LT~:Gs#
privateint p = 1; // 页编号 _5oTNL2
privateint num = 20; // 每页的记录数 F^i3e31*t
privateList<E> results = null; // 结果 Wv;0PhF
/sE,2X*BT
/** :cT)M(o
* 结果总数 ~P4C`Q1PT#
*/ $*Ucfw1T
publicint getCount(){ /F*Y~>*% 1
return count; h [TwaR
} h3ygL" k
jh5QIZf=
publicvoid setCount(int count){ NVyBEAoh
this.count = count; w_9^YO!!
} JzyCeM =
,UNb#=it
/** ZoW1Cc&p
* 本结果所在的页码,从1开始 z+"tAVB[i
* uZqL'l+/y
* @return Returns the pageNo. B=_w9iVN
*/ o`U}uqrO
publicint getP(){ ZlT }cA/n
return p; pu-HEv}]a|
} YW}$e W*
x.Sf B[SZ
/** i'>6Qo
* if(p<=0) p=1 zp:dArh0
* =Tj{)=^/#
* @param p &,X}M
*/ mG~_*8}e<
publicvoid setP(int p){ ("$/sT
if(p <= 0) E$d#4x
p = 1; &5CRXf
this.p = p; m4:c$5
}
~?ab_CY
^7gGtz2
/** zj
6I:Qr
* 每页记录数量 fPR_3qgQ
*/ @Jt$92i5PS
publicint getNum(){ |23F@s1
return num; wi(Y=?=
} ]vrZGX
a+
ER0
Yl
/** du65=w4E!
* if(num<1) num=1 ?OD$`{1
*/ ]#tB[G
publicvoid setNum(int num){ !3Q0Ahf
if(num < 1) Y.^L^ "%dF
num = 1; p|>*M\LE#
this.num = num; +8Xjk\Hi
} I!x.bp~V!
KX)n+{
/** 2d)Dhxzxk
* 获得总页数 L%'J]HL-
*/ ?
SFBUX(p
publicint getPageNum(){ 144Y.
return(count - 1) / num + 1; AdX))xgl
} tOwn M1
:(
!_QI<=X
/** f|[7LIdh-
* 获得本页的开始编号,为 (p-1)*num+1 (gt\R}
*/ K-qWT7<
publicint getStart(){ u]^s2v
return(p - 1) * num + 1; qeZG/\,
} l:HQ@FX
.OPknC
/** ,Qj G|P
* @return Returns the results. 727#7Bo
*/ S%SYvA
publicList<E> getResults(){ *x36;6~W;
return results; Llfl I
} \)PB p
v{u3[c
public void setResults(List<E> results){ ;6tra_
this.results = results; _l
d.Xmvd
} ?]Yic]$n
ot0teNF
public String toString(){
hkK>h
StringBuilder buff = new StringBuilder ddn
IKkOp
&l(T},-X
(); 7)?C+=,0
buff.append("{"); H2X_WSwm
buff.append("count:").append(count); @0 +\:F
buff.append(",p:").append(p); P1#g{f
buff.append(",nump:").append(num); r!r08yf
buff.append(",results:").append xfk
-Ezv
Yuv(4a<M%
(results); tXE/aY*I
buff.append("}"); dOjly,!
return buff.toString(); pF;.nt)
} b
74!Zw
7HkO:/
} TWP@\ BQ
>AEp\*
D
T5d]MU