Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 #)]E8=}
WqQU@sA
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 #w|5jN?
dlR_ckp
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 }LQC.!
qnXTNs
?b
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 |IN[uQ
n}q$f|4!
。 AG>\aV"b
uY]0dyI
分页支持类: |'$ l7
?oKL&I@
java代码: ve fU'
n"Z |e tZ4
Y{+3}drJE
package com.javaeye.common.util; *)D1!R<\,R
:j,}{)5=
import java.util.List; $DE&J4K
CmHyAw(
publicclass PaginationSupport { `{o$F ::(
+?AW>&68y
publicfinalstaticint PAGESIZE = 30; ``4?a7!!
4.w"(v9 V
privateint pageSize = PAGESIZE; V;;#/$oU:4
N}mh}
privateList items; w
&
P&7
]\dHU.i
privateint totalCount; t^U^Tr
Ao"C<.gUYP
privateint[] indexes = newint[0]; 2y%R:Mu
]r959+\$
privateint startIndex = 0; Dr+ Ps
nNQ-"t
public PaginationSupport(List items, int ShGp^xVj
) EXJ
totalCount){ ]0-<>
setPageSize(PAGESIZE); vQHpf>o
setTotalCount(totalCount); QN g\4%
setItems(items); FmD +8=
setStartIndex(0); VB"(9O]
} iRve)
ix*muVBj.
public PaginationSupport(List items, int x0<^<D &Q
0T9.M(
totalCount, int startIndex){ "
"%#cDR
setPageSize(PAGESIZE); 6bL~6-h%)
setTotalCount(totalCount); 1-o V-K
setItems(items); `D2Mss$!
setStartIndex(startIndex); ArXl=s';s4
} !_x*m@/
n&d/?aJ7a\
public PaginationSupport(List items, int Nog(VN4I&
X<euD9?
totalCount, int pageSize, int startIndex){ mb{q(WEPP
setPageSize(pageSize); "~\*If
setTotalCount(totalCount); N RSU+D-z
setItems(items); P
}Te"Y
setStartIndex(startIndex); Uk'U?9O
} vpLMhf`
R=$Ls6z
publicList getItems(){ Qxq-Mpx{
return items; [r9d<Zi}{
} nzuF]vo
xS+rHC
publicvoid setItems(List items){ eY}V9*.v
this.items = items; wS$46M<
} >nM%p4E
UA(;fZ@
publicint getPageSize(){ >r}Vf9 5[N
return pageSize; BS2?!;,8
} N!c
gN
ChE_unw
publicvoid setPageSize(int pageSize){ vgThK9{m;
this.pageSize = pageSize; w}`3 d@
} hSMV&Cs
P
{H{UKs#
publicint getTotalCount(){ Le@?
/
return totalCount; sfI N)jh
} .
\F7tc8?
'9q6aM/&
publicvoid setTotalCount(int totalCount){ RL&lKHA
if(totalCount > 0){ }0{B
this.totalCount = totalCount; ~gdd cTp
int count = totalCount / k
,fTW^ ?
i!,HB|wQ
pageSize; Ekjf^Uo
if(totalCount % pageSize > 0) ])N%^Qe$U
count++; %wL,v.}
indexes = newint[count]; .@k *p >K
for(int i = 0; i < count; i++){ KyLp?!|>
indexes = pageSize *
MZ~.(&
Pfan7fq+
i; TB#Nk5
} zH=hIVc
}else{ )`Ed_F}k
this.totalCount = 0; p+<}YDMb
} k?j Fh6%
} ipZHSA
9,WG!4:+W
publicint[] getIndexes(){ @]?R2bI
return indexes; /^4"Qv\@/
} *h:kmT
zYr z08PJ
publicvoid setIndexes(int[] indexes){ D9o*8h2$
this.indexes = indexes; qjLo&2)
} _6rKC*Pe1
bU+9Gi@v
publicint getStartIndex(){ tIGs>, a=
return startIndex; xa#gWIP*
} N-%#\rPq.
(\vXA4Oa,
publicvoid setStartIndex(int startIndex){ . r`[
if(totalCount <= 0) c<tmj{$
this.startIndex = 0; -3vh!JMN
elseif(startIndex >= totalCount) 968^ "T#
this.startIndex = indexes E em
g
$?f]ZyZr.
[indexes.length - 1]; =P]GPEz_
elseif(startIndex < 0) 5~l2!PY
this.startIndex = 0; PEzia}m
else{ gZ` DT
this.startIndex = indexes `bqzg
7$_
:sJ
[startIndex / pageSize]; wd+O5Lr.R
} .bfST.OA
} ?Ib}
b:Dg}
publicint getNextIndex(){ \h#9oPy
int nextIndex = getStartIndex() + sHs g_6~
Vp7b4n<
pageSize; Fu##'#
if(nextIndex >= totalCount) @L8;VSI
return getStartIndex(); Z4@y?fv7s
else xA-jvu9@
return nextIndex; =4> @8=JA
} OX3Xy7
qZbHMTnT6
publicint getPreviousIndex(){ e5OVq
,
int previousIndex = getStartIndex() - X6kaL3L}
|Puj7Ru
pageSize; 0jTMZ<&zZ
if(previousIndex < 0) =|V"#3$f
return0; e &Rb
else 4 J8Dh;a`
return previousIndex; Cuv|6t75'
} XhA4:t
UkfA}b^@v
} b1)\Zi
v,0<9!'v
})7K S?
/7vE>mSY
抽象业务类 0WXVc
java代码: VIg\]%qse
E9R]sXf8
hS_.l}0yf
/** iT$d;5_pU
* Created on 2005-7-12 8&?p
*/ `^e*T'UPl
package com.javaeye.common.business; bd{\{[^S!
3+zzi
import java.io.Serializable; 5rN7':(H!%
import java.util.List; k=|K|
AY;<q$8j%,
import org.hibernate.Criteria; zq=&4afOE
import org.hibernate.HibernateException; t=
*Jg/$
import org.hibernate.Session; Hz? ,#>{
import org.hibernate.criterion.DetachedCriteria; O{ BW;Deo
import org.hibernate.criterion.Projections; ;sQ20 B'
import f1\7vEE,
_yJ|`g]U3
org.springframework.orm.hibernate3.HibernateCallback; Ql8^]gbp+
import KBj@V6Q
y#e ?iE@
org.springframework.orm.hibernate3.support.HibernateDaoS SwJHgZ&
,!H\^Vfl
upport; hXTYTbTX
Q@Dkl
F
import com.javaeye.common.util.PaginationSupport; niAZ$w
WKOI\
public abstract class AbstractManager extends c/RT0xql*
RNe9h lr
HibernateDaoSupport { Gym#b{#":
Ys%'#f
privateboolean cacheQueries = false; t%HI1eO7h
FE}s#n_Pd
privateString queryCacheRegion; kyu2)L2u
!mae^A1
publicvoid setCacheQueries(boolean ]_\AHnJ
q|Fjm]AF
cacheQueries){ L6xB`E9
this.cacheQueries = cacheQueries; AoU_;B\b%
} q#m!/wod
J@gm@ jLc
publicvoid setQueryCacheRegion(String "u5KbJW
$E @ouX?
queryCacheRegion){ jJ<;2e~OW
this.queryCacheRegion = AHWh}~Yi
X98#QR#m
queryCacheRegion; BjB&[5?z
} "]<w x_!+}
0}D-KvjyP
publicvoid save(finalObject entity){ 4uPH
getHibernateTemplate().save(entity); H7}g!n?
} L9$&-A9ix
T?#s'd
publicvoid persist(finalObject entity){ i0b.AA
getHibernateTemplate().save(entity); \#2
s4RCji
} [\a:4vDAbi
^8Z@^M&O"
publicvoid update(finalObject entity){ ]2PQ X4t0
getHibernateTemplate().update(entity); y]7%$*
<
} jQ)L pjS1
re/xs~
publicvoid delete(finalObject entity){ /Bh>
getHibernateTemplate().delete(entity); HS(U4
} OelU
D/[$
G"{4'LlA
publicObject load(finalClass entity, [.ey_}X8
2'Y{FY_Z
finalSerializable id){ PY2[S[
return getHibernateTemplate().load a^(2q{*
n
3h^VQ*]G
(entity, id); {N"*olx
} 7MoR9,(
}|SIHz!R
publicObject get(finalClass entity, 6-ti Rk~
w"BIv9N
finalSerializable id){ t@6w$5:}
return getHibernateTemplate().get *.:! Ax
PP],HB+*[
(entity, id); "~_$T@^k>
} }#&~w0P
sbgJw
publicList findAll(finalClass entity){ eVrnVPkM
return getHibernateTemplate().find("from )=y.^@UT@
El {r$-}
" + entity.getName()); *q}FV2
} gt~9"I
LNaeB(z"
publicList findByNamedQuery(finalString @`5QG2
KM 5jl9Vv
namedQuery){ <>VIDE
return getHibernateTemplate Qg[heND
b$dBV}0 L
().findByNamedQuery(namedQuery); 8>ESD}(
} xC'mPcU8
t?KUK>>w
publicList findByNamedQuery(finalString query, ::v;)VdX+*
-Sx0qi'%
finalObject parameter){ aXX,Zu^
return getHibernateTemplate o
T:j:n
1k$2LQ
().findByNamedQuery(query, parameter); :,jPNuOA
} o1Ne+Jt
,tau9>!
publicList findByNamedQuery(finalString query, ix:2Z-
33*^($bE&
finalObject[] parameters){ EN)YoVk
return getHibernateTemplate KuIkul9^%
93 [rL+l.Y
().findByNamedQuery(query, parameters); y2U/$%B)G
} :2 _0L
y:~eU
publicList find(finalString query){ ,|6Y\L
return getHibernateTemplate().find S> .q5
#,t2*tM
(query); P`7ojXy
} w8G7Jy
LFl2uV"
publicList find(finalString query, finalObject "v@);\-V
6euR'd^Qi
parameter){ R_t~UTfI;
return getHibernateTemplate().find "tfn?n0
yVT&rQ"{
(query, parameter); Um/CR!
} _c[|@D
3xRM
1GgO
public PaginationSupport findPageByCriteria n/xXQ7y
3Wjq >\
(final DetachedCriteria detachedCriteria){ km9Gwg/zT
return findPageByCriteria 5BrU'NF
kZJt~}
(detachedCriteria, PaginationSupport.PAGESIZE, 0); eH ;Wfs2f
} f#*h^91x
f;e_04K
public PaginationSupport findPageByCriteria 2j2mW>Z
Ga]47pQ"F
(final DetachedCriteria detachedCriteria, finalint u9esdOv
`Q:de~+AM{
startIndex){ ~&t!$
return findPageByCriteria { k
kAqJ
lt }r}HM+
(detachedCriteria, PaginationSupport.PAGESIZE, ;+TMx(
7ESN!
startIndex); &\JK%X.Jlt
} /TzNdIv
Q1aHIc
public PaginationSupport findPageByCriteria 976E3u"Vt
" ]aQ Hh]f
(final DetachedCriteria detachedCriteria, finalint AEB/8%l};v
3X,]=f@_
pageSize, vEu
Ka<5
finalint startIndex){ xylpiSJ
return(PaginationSupport) es.jh
E~'q?LJOB
getHibernateTemplate().execute(new HibernateCallback(){ 7bctx_W&6
publicObject doInHibernate x*NqA(r
Su$18a"Bc
(Session session)throws HibernateException { _Ngx$
Criteria criteria = }9{dR4hD
hfJrQhmE
detachedCriteria.getExecutableCriteria(session); H|grbTv,
int totalCount = &mX5&e
`Af{H/qiI
((Integer) criteria.setProjection(Projections.rowCount GwTT+
^`l"'6
()).uniqueResult()).intValue(); {
z-5GH|
criteria.setProjection l\q*%'Pe
s@[C&v
(null); Q&oC]u(="&
List items = 5oVLv4Z9u
^>3tYg&7
criteria.setFirstResult(startIndex).setMaxResults L4MxU 2
$ \? N<W
(pageSize).list(); x, G6\QmA
PaginationSupport ps = i}.{m Et
5LDQ^n
new PaginationSupport(items, totalCount, pageSize, it(LphB8
G>
f^ 2
startIndex); CnxK+1n l
return ps; Nr>c'TH
} 4JX`>a{<
}, true); /X(@|tk:
} #JK;&Dg!
;k9
?
public List findAllByCriteria(final yd7lcb
[
p:DL:^zx
DetachedCriteria detachedCriteria){ Y}AmX
return(List) getHibernateTemplate 3!i.Fmo
Gg
7WmL
().execute(new HibernateCallback(){ Xz;et>UD*B
publicObject doInHibernate .OVW4svX
TYs+XJ'Xj
(Session session)throws HibernateException { + ")qi=
Criteria criteria = 1x~%Ydy
$sA,$x:^xI
detachedCriteria.getExecutableCriteria(session); 8[6ny=S`
return criteria.list(); >2l13^Y
} l.__10{
}, true); -@EBbM&
} zvek2\*rO
(|yRo
public int getCountByCriteria(final Wl^prs7}c
}*fW!(*
DetachedCriteria detachedCriteria){ += |hMQ;
Integer count = (Integer) 71oFm1m{
zjluX\
getHibernateTemplate().execute(new HibernateCallback(){ Z!C`f/h9
publicObject doInHibernate pFpQ\xc9$
kx"hWG4
(Session session)throws HibernateException { "#mXsp-ut
Criteria criteria = [}W^4,
?noETH z)
detachedCriteria.getExecutableCriteria(session); y3
({(URU
return _hAj2%SL
0EL\Hd
criteria.setProjection(Projections.rowCount c8bca`
7\7 Brw4
()).uniqueResult(); ?z \q Mu
} F&W0DaH
}, true); 21[K[ %
return count.intValue(); tnQR<
} uM6CG0
} (PCimT=5
47)+'`
K;@RUy~
9_M H
N0y;PVAGu
J6@(X8w{j
用户在web层构造查询条件detachedCriteria,和可选的 ^4xlZouCb
&&(4n?
startIndex,调用业务bean的相应findByCriteria方法,返回一个 %Y)PH-z
)@8'k]Glw.
PaginationSupport的实例ps。 }<(
"0jC
q7 %=`l
ps.getItems()得到已分页好的结果集 b>hBct}
ps.getIndexes()得到分页索引的数组 i Q]T+}nn_
ps.getTotalCount()得到总结果数 y1,?ZWTayr
ps.getStartIndex()当前分页索引 ]y1$F
Ir+
ps.getNextIndex()下一页索引 wQo6!H"K
ps.getPreviousIndex()上一页索引 ..P=D <'f
Zd[y+$>
)0Y #-=.<
TIK/ %T
A%NK0j$;}
`l[6rf_.
1S*8v 7
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 w>NZRP_3
p6&LZ=tL3
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 hYP6z^
SeRK7Q&_
一下代码重构了。 ,_"7|z wb
~6@c]:
我把原本我的做法也提供出来供大家讨论吧:
rE1np^z7
cM> G>Yzo
首先,为了实现分页查询,我封装了一个Page类: ! /|0:QQi
java代码: #hy5c,}>
.RQ Xxw
Ct =E;v7}
/*Created on 2005-4-14*/ _Ep{|]:gw
package org.flyware.util.page; ?MV[=LPL
tMD^$E"C
/** U<ku_(2"#
* @author Joa -dc5D@4`#s
* Q{H!s_6iyv
*/ ~.PPf/
Z8]
publicclass Page { !L0E03')k
()JYN5
/** imply if the page has previous page */ !^Z[z[
privateboolean hasPrePage; 3X-{2R/ 3
%KabyvOl)
/** imply if the page has next page */ Xhq? 7P$3
privateboolean hasNextPage; 7`u A
X <ba|(
/** the number of every page */ `'G),{ j
privateint everyPage; $4$?M[
h8iaJqqvJ
/** the total page number */ ~,1-$#R
privateint totalPage; CO:m]oj
bBeFL~
/** the number of current page */ I&'S2=s
privateint currentPage; K^]?@oHO
Mv7w5vTl
/** the begin index of the records by the current FT3,k&i
nU?Xc(Xy
query */ 3&a*]
privateint beginIndex; X*0eN3o.
C)&gL=O*$
_-|yCo
/** The default constructor */ tK s4}vW
public Page(){ ;9!yh\\
|h^G $guw
} +s+PnZ%0V
wa(Wit"-
/** construct the page by everyPage T 9<H%iF
* @param everyPage ;i-D~Np|
* */ ^huBqEs
public Page(int everyPage){ VuO)
this.everyPage = everyPage; HonAK
} "EOk^1,y
#cp$ltY
/** The whole constructor */ ~u?x{[
public Page(boolean hasPrePage, boolean hasNextPage, :r
vO8.\
)<}VP&:X
hIzPy3
int everyPage, int totalPage, >"sKfiM)b
int currentPage, int beginIndex){ Tg<>B
this.hasPrePage = hasPrePage; QRg"/62WCD
this.hasNextPage = hasNextPage; /\3XARt
this.everyPage = everyPage; `F-Dd4B
this.totalPage = totalPage; *FLTz(T
this.currentPage = currentPage; IJ
#v"! D
this.beginIndex = beginIndex; 5JU(@}Db
} 6gg# Z
<750-d!
/** <@x+N%C
* @return RBv=
* Returns the beginIndex. mk[d7Yt{O
*/ iaa (ce
publicint getBeginIndex(){ \fM!^
return beginIndex; m|#(gX|F
} =B o4yN
8ZNd|\
/** e$/Zb`k
* @param beginIndex qN`]*baS
* The beginIndex to set. 2\z`G
*/ B!E<uVC
publicvoid setBeginIndex(int beginIndex){ 0o"<^]
_|
this.beginIndex = beginIndex; @WDqP/4
} X/;"CM
R<0!?`b
/** ,39$iHk
* @return zhR_qW+
* Returns the currentPage. x9&tlKKxf
*/ JI[rIL\Ey
publicint getCurrentPage(){ N?U&(@p
return currentPage; `MpC<sit
} PE;0
jgsiI
qI V`zZc
/** 6q
xUT
* @param currentPage z5o9\.y({
* The currentPage to set. Fb<\(#t
*/ p-(ADQS
publicvoid setCurrentPage(int currentPage){ M;RnH##W
this.currentPage = currentPage; w_z^5\u0
} a,0o{*(u$
?w5nKpG#RI
/** @R-~zOv
* @return )H37a
* Returns the everyPage. z7l;|T
*/ .}hZ7>4-
publicint getEveryPage(){ NM.f0{:cj
return everyPage; ^kR^
QL$
} n'ca*E(
->"h5h
/** gU 2c--`
* @param everyPage d8 BK/b
* The everyPage to set. KJvJUq
*/ 6'sFmC
publicvoid setEveryPage(int everyPage){ x_H7=\pX]
this.everyPage = everyPage; PEQvEruZ}
} rbJ)RN^.
5@&i:vs5y
/** yg[Oy#^
* @return Kn9=a -b?,
* Returns the hasNextPage. [>]VN)_J5
*/ u2.r,<rC*Q
publicboolean getHasNextPage(){ 2S10j%EeI
return hasNextPage; WCfe!P?g
} &40JN}
[Ey%uh
6*
/** %Ty
{1'o
* @param hasNextPage fdH'z:Xao
* The hasNextPage to set. v8fZ?dx
*/ r0$9c
publicvoid setHasNextPage(boolean hasNextPage){ /qQ2@k
this.hasNextPage = hasNextPage; ]#7Y@Yo
} 4[EO[x4C
v%8-Al^G
/** ;0X|*w1JO
* @return `zsk*W1GA
* Returns the hasPrePage. \3Ald.EqtM
*/ kA:;c}p
publicboolean getHasPrePage(){ L!8?2 \5
return hasPrePage; W2.1xNWO
} 6pz:Lfd80
AU?YZEAei
/** Ug'nr
* @param hasPrePage {R8P $
* The hasPrePage to set. jeuNTDjeL
*/ .STf
publicvoid setHasPrePage(boolean hasPrePage){ NwuBe:"@
this.hasPrePage = hasPrePage; xg5@;p
} au}0PnA;
u$/2XO
/** I;m@cSJ|j
* @return Returns the totalPage. EV,NJ3V
* yURh4@
*/ c"&!=@
publicint getTotalPage(){ i.dAL)V
return totalPage; P;91C'T-x
} OsSiBb,W79
>`V|`Zi ?
/** AkQFb2|ir
* @param totalPage ?}Ptb&Vk(
* The totalPage to set. o?hw2-mH
*/ r_<i*l.
publicvoid setTotalPage(int totalPage){ \C\y'H5
this.totalPage = totalPage; A)a+LW'=u
} 4Jy,IKPp
NeZYchR
} F4{. 7BT
7ofH@U
\^W?
(']z\4o
exN#!&;
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 a|{<#<6n(
k.R/X
个PageUtil,负责对Page对象进行构造: ZZJ"Ny.2
java代码: YZtA:>;p
CpdY)SMSL
x3F L/^S
/*Created on 2005-4-14*/ #K*q(ei,7h
package org.flyware.util.page; ]x{ H
_^sSI<&m
import org.apache.commons.logging.Log; ^
J@i7FOb
import org.apache.commons.logging.LogFactory; !Kqj&y5
E1Aa2
/** x=|@AFI
* @author Joa {j4:.fD
* w)SxwlW}
*/ _Wsk3AP
publicclass PageUtil { \D k^\-
=y/Lbe}:
privatestaticfinal Log logger = LogFactory.getLog h pes
O.f3 (e!
(PageUtil.class); X?xm1|\
c@{^3V##T
/** aZ3 #g
* Use the origin page to create a new page 1ucUnNkcV
* @param page U1tPw`0h
* @param totalRecords f5XcBW9E
* @return {$=%5
*/ BqA wo
publicstatic Page createPage(Page page, int X"59`Yh
%31K*i/]
totalRecords){ ?O^:j!C6
return createPage(page.getEveryPage(), qGUe0(
%pKs- n`
page.getCurrentPage(), totalRecords); h0QQP
} AQGE(%X
&
b2(Y4
/** 5fv6RQD
* the basic page utils not including exception %Ne>'252y
XE%6c3s
handler I}3K,w/7mi
* @param everyPage bv" ({:x
* @param currentPage Bm>(m{sX>
* @param totalRecords iEO2Bil]
* @return page EB<tX`Wp
*/ f3|=T8"t
publicstatic Page createPage(int everyPage, int Q#bo!]H{t
:#KURYO<
currentPage, int totalRecords){ 8j+;Xlh
everyPage = getEveryPage(everyPage); \:28z
currentPage = getCurrentPage(currentPage); WuXRL}!\,
int beginIndex = getBeginIndex(everyPage, mw.aavB
@D{[Hj`<
currentPage); !-Q!/?
int totalPage = getTotalPage(everyPage, {D.0_=y~2
45JLx?rN_
totalRecords); @}RyW&1Z
boolean hasNextPage = hasNextPage(currentPage, QCnVZ" !(
Y0'^S<ox
totalPage); #Jb$AA!z
boolean hasPrePage = hasPrePage(currentPage); : |(B[
$
$+z^%'_
returnnew Page(hasPrePage, hasNextPage, @2O\M ,g5
everyPage, totalPage, (Gsg+c
currentPage, h"m7r4f
9 peB+URV
beginIndex); ]&BFV%kw
} 3Or3@e5r
b=go"sJ@>(
privatestaticint getEveryPage(int everyPage){ Um&@
0C+L
return everyPage == 0 ? 10 : everyPage; 2l%iXK[
} (acRYv(
_~<TAFBr
privatestaticint getCurrentPage(int currentPage){ uf3 gVS_h=
return currentPage == 0 ? 1 : currentPage; I9 aber1
} {(Z1JoSl
Onyq'
privatestaticint getBeginIndex(int everyPage, int
.l'QCW9
`/iN%ZKum
currentPage){ 9LRY
return(currentPage - 1) * everyPage;
=7@
} k{8N@&D
pp _ddk
privatestaticint getTotalPage(int everyPage, int >0$5H]1u
0$
EJ4
totalRecords){ w|#79,&
int totalPage = 0; 9 f+7vCA
S)h1e%f,
f
if(totalRecords % everyPage == 0) =]Bm>67"
totalPage = totalRecords / everyPage; =^}2 /vA
else u^9,u/gj
totalPage = totalRecords / everyPage + 1 ; 81g0oVv
evP`&23tP
return totalPage; CjCnh7tm
} W5 }zJ)x
}]) f^
privatestaticboolean hasPrePage(int currentPage){ OMNdvrE*=O
return currentPage == 1 ? false : true; 2/WXdo
} ? 'nMZ
:W55JD'
privatestaticboolean hasNextPage(int currentPage, N~YeAe~+
ABf#!G
int totalPage){ KcE=m\ h
return currentPage == totalPage || totalPage == BC+qeocg
_l<"Qqt
0 ? false : true; PVQ%y
} X?a67qL
umYdr'p!v
a WC
sLH
} F!'"mU<f
mZ%\`H+
SuSZ,>
P'';F}NwfX
V00zk`PH
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。 4|UIyDt8
Pr"ESd>Y
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 qKXn=J/0tA
zyE yZc?
做法如下: v%w]Q B
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 fk_i~K
.l!Z=n|
的信息,和一个结果集List: ^
T S\x/P
java代码: MvA_tRO
'rgV]Oy
vJ s/ett
/*Created on 2005-6-13*/ 7#`:m|$
package com.adt.bo; "~6BC
*{bqHMd4L
import java.util.List; 7dRU7p>
uq_SF.a'v
import org.flyware.util.page.Page; "k/x+%!Spc
nNr3'6lz
/** BH1To&ol
* @author Joa aJts
*/ >#Yq&@G
publicclass Result { Bf.RYLsh6
V^D#i(5
private Page page; VrG |/2
uB?YJf .T@
private List content; TnrMR1Zx
JP]K\nQx'
/** H+Wd#7l,
* The default constructor .0
K8h:I
*/ \v<}{\.|$
public Result(){ R:E:Y|&#
super(); L xO'$oKZV
} 0J"3RTt
&W%TY:Da|
/** DX|kO
* The constructor using fields cW2:D$Pe
* ,$Mw/fA
* @param page :d;5Q\C`
* @param content 2t'&7>Ys{
*/ :>;#/<3{
public Result(Page page, List content){
J&?kezs
this.page = page; S;C3R5*:
this.content = content; gVc[`(@h
} 0qv)'[O
oT'XcMn
/** Jq->DzSmj/
* @return Returns the content. W~qo
`r
*/ uE2Yn`Ha
publicList getContent(){ ME(!xI//JZ
return content; fHiCuF
} mTt 9 o9E
T
&1sfS,
/** BdTj0{S1u
* @return Returns the page. j8b:+io
*/ Cn,dr4J[
public Page getPage(){ t
t=$:}A
return page; t%%I.zIV7
} `u-}E9{
lZ|Ao0(
/** &xVWN>bd^
* @param content Q'N<jX[
* The content to set. j(SQNSFD
*/ _i&\G}mrC
public void setContent(List content){ mnePm{
this.content = content; (?Yz#Yf
} LTF%bAQ,
al2v1.Y}
/** >wn&+%i&
* @param page W^x[maz
* The page to set. @1pdyKK
*/ =F`h2 A;a
publicvoid setPage(Page page){ gm8H)y,
this.page = page; ^a]:GPc
} nL$tXm-x
} Au
{`oxD
>TE&myZ?*
biJU r^n
%ug`dZ/
5H79) n>
2. 编写业务逻辑接口,并实现它(UserManager, w NPZ[V:
|(/"IS]
UserManagerImpl) F"q3p4-<>
java代码: 1)%o:Xy o
</fnbyGR
w-KtxG(
/*Created on 2005-7-15*/ QMIQy
package com.adt.service; _CgD7d
FvkKM+?F
import net.sf.hibernate.HibernateException; \6N\6=t!A
YC$pT
import org.flyware.util.page.Page; 6O"0?wG+
&^}w|J?
import com.adt.bo.Result; 2`z+_DA
E?;W@MJi
/** m'S-h'a
* @author Joa U;^{uQJ+,
*/ 3RD Q{&J:
publicinterface UserManager { .RT5sj\d
{>i'Pb0mG|
public Result listUser(Page page)throws v4&*iT
5W'T7asOh
HibernateException; R_^:<F0
:( `Q4D~l
} .{Xi&[jw
x&;SLEM
(<f[$ |%
N>/U%01a
wC[J=:]tA5
java代码: -0W;b"]+A
+n0y/0Au
SZgH0W("L
/*Created on 2005-7-15*/ |h3YL!
package com.adt.service.impl; ^Ab|\5^3
Oz+>I^Q
import java.util.List; cgU7)`0j
# OJD<=")
import net.sf.hibernate.HibernateException; \dP2xou=
rsP1?Hxq
import org.flyware.util.page.Page; zRz3ot,|
import org.flyware.util.page.PageUtil; ci$o~b6V
FNUue
import com.adt.bo.Result; |ey6Czm
import com.adt.dao.UserDAO; 7==Uoy*O
import com.adt.exception.ObjectNotFoundException; 4g6d6~098;
import com.adt.service.UserManager; iQA
f
4Fnr8 r8W
/** ^@N@gB
* @author Joa fQv^=DI#
*/ 4WNWn#M
publicclass UserManagerImpl implements UserManager { <5nz:B/
O=yUAAD$
private UserDAO userDAO; Ly^r8I
0iwx$u7[
/** iR_X,&p
* @param userDAO The userDAO to set. !7_Q_h',
*/ 5T,`j=\
publicvoid setUserDAO(UserDAO userDAO){ l9-(ofY*J
this.userDAO = userDAO; d`Wd"LJ=
} #"TTI
vd0
En[cg
/* (non-Javadoc) *t~(_j
* @see com.adt.service.UserManager#listUser E*CY/F I_
-qs9a}iL
(org.flyware.util.page.Page) WT1ch0~2
*/ P[D^*}
public Result listUser(Page page)throws .~Td/o7
A$
s4Q0Mf
HibernateException, ObjectNotFoundException { vmL0H)q
int totalRecords = userDAO.getUserCount(); ba
,2.|
if(totalRecords == 0) @o_-UsUX
throw new ObjectNotFoundException Yw./V0Z{@
' (ql7
("userNotExist"); q),yY]5
page = PageUtil.createPage(page, totalRecords); JD,/oL.KA
List users = userDAO.getUserByPage(page); A9[l5E
returnnew Result(page, users); 1}'|HAu
} +}%4]O;
MbF.KmV
} <zrGPwk
nqr[HFWs
~Z T(@w
1{_;`V
6VIi
nuOW
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查
d':c
@<l7"y;\
询,接下来编写UserDAO的代码: }O8$?7j(
3. UserDAO 和 UserDAOImpl: 6tj+
java代码: q&7J1
^xFZ;Yf
8nNRn[oS
/*Created on 2005-7-15*/ bz,C%HFA
package com.adt.dao; !}<Y^="
FL-sXg
import java.util.List; ,|}Pof=]xk
&_G^=Nc,H
import org.flyware.util.page.Page; OTSbhI'v
.I<#i9Le
import net.sf.hibernate.HibernateException; I)T]}et
Ub0g{
/** iku) otUc
* @author Joa aO6w:IO
*/ {4\(HrGNk
publicinterface UserDAO extends BaseDAO { .t$~>e
.
'f]\@&Np
publicList getUserByName(String name)throws :Fu.S1j$
O\8_;Gc;
HibernateException; WF`y j%0
{|a=
publicint getUserCount()throws HibernateException; .r $d
8J
&E0P`F,GQA
publicList getUserByPage(Page page)throws yKgA"NaM
{p-&8-
HibernateException; ^pIT,|myY7
7ZqC1
} Ar,B7-F!
xmsw'\
hv2@}<