Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 8LM 91
%uWq)D4r
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 !uJDhC
Q(J6;s#b
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 8KU5x#
.G|9:b
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 =u#xPI0:
wN4N2
。 LmQS;/:
Sx", Zb
分页支持类: $8"G9r
>SR!*3$5
java代码: chr^>%Q_
OLS. 0UEc
[Q5>4WY
package com.javaeye.common.util; tEXY>=
3Bk_4n
import java.util.List; FV->226o%
4)XZ'~|
publicclass PaginationSupport { SZ[,(h
sF`ELrR \
publicfinalstaticint PAGESIZE = 30; &n)=OConge
+7]]=e<[E
privateint pageSize = PAGESIZE; g~i%*u,Y<
+jPs0?}s
privateList items; [9S?
zJ2dPp~u
privateint totalCount; aX'R&R
KPcOW#.T
privateint[] indexes = newint[0]; A=S_5y
1D/9lR,
privateint startIndex = 0; Y"RjMyQh
,XJ
Xw(LM
public PaginationSupport(List items, int IY='tw
O4mSr{HCp
totalCount){ Fuuy_+p@G
setPageSize(PAGESIZE); W"a% IO%'
setTotalCount(totalCount); @{|vW
setItems(items); dO{a!Ca
setStartIndex(0); quPNwNy
} GYq.!d@O
Qg\{d)X[N
public PaginationSupport(List items, int SQ_w~'(
Bi'qy]%
totalCount, int startIndex){ uGxh}'&
setPageSize(PAGESIZE); `(rnD
setTotalCount(totalCount); `?f Y!5BA
setItems(items); @6N$!Q?
setStartIndex(startIndex); ?pF7g$>q
} .(7end<
?7Y6: zo$^
public PaginationSupport(List items, int mjwh40x.o
O"D0+BK79e
totalCount, int pageSize, int startIndex){ <^APq8>
setPageSize(pageSize); A+:X
setTotalCount(totalCount); !X5~!b^*
setItems(items); X{j`H\'L
setStartIndex(startIndex); Q,.[y"m9Y.
} dF?:&oP]
sKvz<7pag
publicList getItems(){ ,o3{?o]s
return items; ;6T>p
} $Z!$E,@c
{O4y Y=G
publicvoid setItems(List items){ g=T
!fF=
this.items = items; <]jKpJ{3N
} k{?Pgf27
/R2K3E#
publicint getPageSize(){ W.fsW<{4j
return pageSize; 1I{^]]qw
} =%O@%v
hd@ >p.
publicvoid setPageSize(int pageSize){ BO3#*J5S\
this.pageSize = pageSize; 8N8N)#A[
} n%M-L[n
|N{?LKR
%
publicint getTotalCount(){ zuq7 x7
return totalCount; eiNF?](3O
} _wC4n }J
:j}]nS
publicvoid setTotalCount(int totalCount){ )9.i'{{ 0
if(totalCount > 0){ /Lf+*u>"
this.totalCount = totalCount; Z uh!{_x;
int count = totalCount / / p_mFA]@
u0)~Im,X
pageSize; [M7&
if(totalCount % pageSize > 0) [HV>4,,3"
count++; 2Op\`Ht&
indexes = newint[count]; o:E_k#Fi
for(int i = 0; i < count; i++){ <K$X>&Ts
indexes = pageSize * ?x*Ve2+]
-t<8)9q(
i; O[tOpf@s.
} ]Tb ?k+a
}else{ y2>XLELy
this.totalCount = 0; JwkMRO
} Bbb_}y|CA
} ymIjm0jVh
LV^V`m0#
publicint[] getIndexes(){ ((2 g
return indexes; NaR/IsN8%
} 2W}f|\8MX
3M;[.b
publicvoid setIndexes(int[] indexes){ FXHcy:)}G
this.indexes = indexes; C;u8qVI
} ,r&:C48dI
4z_ >CiA
publicint getStartIndex(){ "I)*W8wTn
return startIndex; dKOW5\H'
} [_jd
8f^QO:
publicvoid setStartIndex(int startIndex){ /GzA89N(
if(totalCount <= 0) 63J_u-o
this.startIndex = 0; XzX-Q'i=n0
elseif(startIndex >= totalCount) O[N}@%HMW
this.startIndex = indexes 1kiS."77x
k,~I>qg
[indexes.length - 1]; HF3W,eaqK
elseif(startIndex < 0) QWo_Zg0"
this.startIndex = 0; xHA6
else{ b"au9:F4@7
this.startIndex = indexes w4:
HG1)q\Xd
[startIndex / pageSize]; syEWc(5
} 4oY<O
} #s'UA!)
y%y F34
publicint getNextIndex(){ JAjXhk<=
int nextIndex = getStartIndex() + !N`$`qAK
986y\9Zu
pageSize; "Y9PS_u(~
if(nextIndex >= totalCount) 3$.R=MQ7
return getStartIndex(); }mz6z<pJ_
else our$Ka31
return nextIndex; ~f.fg@v`+v
} e~Oge
N W/RQ(
publicint getPreviousIndex(){ ST#OO!
int previousIndex = getStartIndex() - (XQBBt
[hLSK-K 9
pageSize; )zFPf]gz
if(previousIndex < 0) &8l"Dl
return0; n/
\{}9
else ,qx;kJJ
return previousIndex; 9]ga\>v
} (8[et m
;*3OkNxa3
} l5> H\
` )9nBZ
4K_ fN
H`js1b1n
抽象业务类 IfGmA.O
java代码: 6;LM1
_
l3d^V&Sk
e?Pzhha
/** 5 A/[x$q
* Created on 2005-7-12 Fk:yj 4'
*/ %gF; A*
package com.javaeye.common.business; 'T(7EL3$}
!+&Rn\e%7
import java.io.Serializable; b(hnou S
import java.util.List; X~aD\%kC7
[d(@lbV0
import org.hibernate.Criteria; i.eu$~F
import org.hibernate.HibernateException; U_/sY9gz(
import org.hibernate.Session; 7^{M:kYC!
import org.hibernate.criterion.DetachedCriteria; .
6wyu7oK
import org.hibernate.criterion.Projections; w]4=uL6
import g]'RwI
oKl^Ttr
org.springframework.orm.hibernate3.HibernateCallback; ZT
UaF4k j
import MwoU>+XB
;.=ZwM]C
org.springframework.orm.hibernate3.support.HibernateDaoS O!0YlIvWv
r<Il;?S6
upport; we6kV-L.
n=HId:XT
import com.javaeye.common.util.PaginationSupport; >~;MQDU5*Y
Kq`C5
public abstract class AbstractManager extends y^7ol;t
C'HW`rh.^
HibernateDaoSupport { C%s+o0b
uF xrv
privateboolean cacheQueries = false; 0P(U^rkR~
/H_,1Fu|
privateString queryCacheRegion; ~16QdwK
kC=e>v
publicvoid setCacheQueries(boolean orGNza"A
< ag|#
cacheQueries){ M;BDo(1
this.cacheQueries = cacheQueries; 9uV'#sR
} +-~:E_G
WaU+ZgDrG
publicvoid setQueryCacheRegion(String #WBlEVx;Z
_JlbVe[<
queryCacheRegion){ @a AR99 M
this.queryCacheRegion = 'A0.(a5
41c]o<!=)j
queryCacheRegion; Dc,h(2
} I~LN)hqd o
P@gVzx)M
publicvoid save(finalObject entity){ pYtG%<
getHibernateTemplate().save(entity); }b9"&io
} c7$L:
)7U^&I,
publicvoid persist(finalObject entity){ [@!.( Hp
getHibernateTemplate().save(entity); D&Xh|}2A
} :r?gD2q
_ >)+
u
publicvoid update(finalObject entity){ P\;L#2n
getHibernateTemplate().update(entity); |}~2=r z
} 7H$0NMP
TU6e,G|t
publicvoid delete(finalObject entity){ _:hrm%^
getHibernateTemplate().delete(entity); o:H^
L,<Tl
} %LeQpbyOR
' `0kW_'
publicObject load(finalClass entity, Vej [wY-c
`Yk~2t"V
finalSerializable id){ #cB=](N
return getHibernateTemplate().load VO_! +
!.(Kpcrg
(entity, id); uSZCJ#'G
} dP>~ExYtm
6S#Y$2
P
publicObject get(finalClass entity, *R] Ob9X
VR86ok
finalSerializable id){ K>=KsG
return getHibernateTemplate().get q=NI}k
v-zi ,]W
(entity, id); -f&16pc1t
} @Q!Jzw#B
bSOxM/N
publicList findAll(finalClass entity){ n#jBqr&!M
return getHibernateTemplate().find("from ;7id![KI4
d~i WV6Va
" + entity.getName()); ?gknJ:
} ?xftr (
EV1x"}D A_
publicList findByNamedQuery(finalString -^ )0c
y v6V1gK
namedQuery){ RrFq"
return getHibernateTemplate Rne#z2Ok
D?+\"lI
().findByNamedQuery(namedQuery); XJx$HM&0M
} $uw[X
)e#KL$B)v
publicList findByNamedQuery(finalString query, =fJDFg
!Zowe*`
finalObject parameter){ PUt\^ke
return getHibernateTemplate C$"N)6%q
Y(aEp_kV
().findByNamedQuery(query, parameter); 1J`<'{*
} #6t 4 vJ1
"r!>p\.0O
publicList findByNamedQuery(finalString query, #w%d
)7$1Da|.
finalObject[] parameters){ @DiXe[kI
return getHibernateTemplate J1i{n7f=@
pbfIO47ZC
().findByNamedQuery(query, parameters); f`ro{p
} `pMI@"m
h |Ofi
publicList find(finalString query){ a`c#-
je
return getHibernateTemplate().find 4LG[i}u.N
=>?;Iv'Z
(query); j@N z
} bjn: e!}
1D*oXE9Ig
publicList find(finalString query, finalObject /_WAF90R?
$Hw
w
parameter){ %bu$t,
return getHibernateTemplate().find C%2BDj
_?]0b7X
(query, parameter); ~lBb%M
} 6Zr_W#SE
g=Gd|
public PaginationSupport findPageByCriteria I5nxY)v
OyI?P_0u
(final DetachedCriteria detachedCriteria){ ` ,lm:x+(0
return findPageByCriteria o#"U8N%r
KCBA`N8
(detachedCriteria, PaginationSupport.PAGESIZE, 0); q=I8W}Zi
} l#%qF Db
\9HpbCHr
public PaginationSupport findPageByCriteria a0wSXd
(p19"p
(final DetachedCriteria detachedCriteria, finalint oo+i3af&7
X8}m
%
startIndex){ WqX$;'}h
return findPageByCriteria *~h@K Qm7
{gL8s
(detachedCriteria, PaginationSupport.PAGESIZE, M =/+q
U yb -feG
startIndex); ,/fB~On-
} QN4{xf:}S
BlLK6"gJT
public PaginationSupport findPageByCriteria .<m${yU{3
fL^$G;_?3
(final DetachedCriteria detachedCriteria, finalint <{ER#}b:O
L3/SIoqd
pageSize, 6TR` O
finalint startIndex){ v3p0
return(PaginationSupport) *F<Ar\f5
(Q]Ww_r~
getHibernateTemplate().execute(new HibernateCallback(){ |wxAdPe
publicObject doInHibernate DpRGPs
5T*Uq>x0
(Session session)throws HibernateException { OLH[F
Criteria criteria = W
u C2LM
OO?;??
detachedCriteria.getExecutableCriteria(session); Ci-CY/]s
int totalCount = D(;jv= "/
X-,mNvz
((Integer) criteria.setProjection(Projections.rowCount !_?K(X~/
1Yk!R9.
()).uniqueResult()).intValue(); Ub,5~I+`
criteria.setProjection `4SwdW n
D'8xP %P
(null); MyZ5~jnr\
List items = &GfDo4$
C
vOH*K'
criteria.setFirstResult(startIndex).setMaxResults >g>L>{
+#RgHo?f
(pageSize).list(); =(==aP
PaginationSupport ps = }5Zmc6S{
KgH_-REN
new PaginationSupport(items, totalCount, pageSize, 1
$m[#3
+ L\Dh.Ir
startIndex); 3(oB[9]s
return ps; "W b>y*S
} @<TC+M5!
}, true); M?S&@\}c
} im-XP@<
Z[ 53cVT^
public List findAllByCriteria(final n8+_Uww
/;X+<Wj
DetachedCriteria detachedCriteria){ 9cIKi#Bl
return(List) getHibernateTemplate p!o?2Lbiw
ip+?k<]z
().execute(new HibernateCallback(){ Leu93f2
publicObject doInHibernate &cpqn2Z
L^FQ|?*
(Session session)throws HibernateException { z%q)}$O
Criteria criteria = <#ng"1J
p
2>\
detachedCriteria.getExecutableCriteria(session); W9rmAQjn
return criteria.list(); !hugn6
} Z?f-_NHg
}, true); O}-+o 1
} shZEE2Dr
$=9g,39
public int getCountByCriteria(final \S_o{0ZY}
:!QT ,
DetachedCriteria detachedCriteria){ 'QdDXw5o
Integer count = (Integer) ii5dTimRJ
iw{rns
getHibernateTemplate().execute(new HibernateCallback(){ BhzcimC)
publicObject doInHibernate uj~(r=%
~]Weyb[N
(Session session)throws HibernateException { ["H2H rI2
Criteria criteria = cK1 Fv6V#
5F78)qu6N
detachedCriteria.getExecutableCriteria(session); Krd0Gc~\|
return wBlo2WY
;S?ei>Q
criteria.setProjection(Projections.rowCount 1>=]lMW
mVd%sWD
()).uniqueResult(); X/f?=U
} 8b:GyC5L
}, true); n`X}&(O
return count.intValue(); S*NeS#!v
} szs.B|3X@*
} {O!B8a
4*&2D-8<K
3rj7]:Vr
7Tc^}Q
cz41<SFL
MMy\u) 4
用户在web层构造查询条件detachedCriteria,和可选的 -KL5sK
-PCFOm"
startIndex,调用业务bean的相应findByCriteria方法,返回一个 T0X+\&W
Oj>;[O"
PaginationSupport的实例ps。 2dCD.9s9~
EX/{W$
&K
ps.getItems()得到已分页好的结果集 f;%=S:3
ps.getIndexes()得到分页索引的数组 3z0%uY[e
ps.getTotalCount()得到总结果数 nC}Y+_wo0
ps.getStartIndex()当前分页索引 G.:QA}FE'
ps.getNextIndex()下一页索引 +F92_a4
ps.getPreviousIndex()上一页索引 Ys>Z=Eky
7n[0)XR>
@Yw>s9X
WCP2x.gb5
HP,{/ $i:
4C }#lW9
gn:&akg
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 P>hR${KE
!>?*gc.<
,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 ";Q}Gs}
4vi[hiV
一下代码重构了。 C ~Doj
VQI[J
我把原本我的做法也提供出来供大家讨论吧: h,ipQ>
8'Iei78Ov
首先,为了实现分页查询,我封装了一个Page类: K2gF;(
java代码: Q"QZ^!zRl
98*C/=^TH{
39bw,lRPV
/*Created on 2005-4-14*/ @2~;)*
package org.flyware.util.page; M Al4g+es
YRyaOrl$<
/** skF}_
* @author Joa fuT Bh6w&
* a(AYY<g
*/ /<k]mY cu
publicclass Page { m>f8RBp]'
0|| 5r#
/** imply if the page has previous page */ 32p9(HQ
privateboolean hasPrePage; ,rX|_4n*
~Kt2g\BSok
/** imply if the page has next page */ 9vBW CCf
privateboolean hasNextPage; ,7)zavA
Ud_0{%@
/** the number of every page */ xk7VuS*
privateint everyPage; _Mi*Fvj
> .K
/** the total page number */ lv#L+}T
privateint totalPage; ?(Xy 2%v
HHL7z,%f
/** the number of current page */ eyy%2>b
privateint currentPage; Jo\karpb
8(]q/g"O
/** the begin index of the records by the current i7mo89S
QsBC[7<jd-
query */ T~
P<Gq},
privateint beginIndex; k54b@U52 h
pp+z5
_adW>-wQ!d
/** The default constructor */ $mxl&Qr>Q;
public Page(){ $ncP#6
XrJLlH>R4
} )3ZkKv;zY
a28`)17z
/** construct the page by everyPage [&)*jc16
* @param everyPage QTU$mC]
* */ 8{ )N%r
public Page(int everyPage){ |?v+8QL,;t
this.everyPage = everyPage; 7w}]9wCN?
} W^i[7 r
h>A~yDT[
/** The whole constructor */ sC_doh_M
public Page(boolean hasPrePage, boolean hasNextPage, h7PIF*7m
e
F.AP)`6+*
P:UR:y([
int everyPage, int totalPage, ywj'O
e41
int currentPage, int beginIndex){ ~<"{u-q#K
this.hasPrePage = hasPrePage; 7*r!-$
this.hasNextPage = hasNextPage; ,L; y>::1
this.everyPage = everyPage; nnTiu,2R
this.totalPage = totalPage; %<1_\N7
this.currentPage = currentPage; WH<\f|xR
this.beginIndex = beginIndex; X$=/H 6R5Z
} ]+Z,HY@;-
>6|Xvtf
/** sW&h?jdf
* @return &X,6v
* Returns the beginIndex. zor
*/ (Ft#6oK"
publicint getBeginIndex(){ SqVh\Nn
return beginIndex; '/3\bvZ
} _pkmHj(
A27!I+M
/** c1<jY~U
* @param beginIndex ,uZz?7mO
* The beginIndex to set. d~y]7h |
*/ 26MoYO!k
publicvoid setBeginIndex(int beginIndex){ UPkc-^BN
this.beginIndex = beginIndex; |21*p#>
} W(EN01d \
wq]vcY9^
/** ~JB4s%&
* @return /}(\P@Z
* Returns the currentPage. ;".]W;I*O
*/ WL;2&S/{@
publicint getCurrentPage(){ x5k6"S"1,
return currentPage; `82^!7 !
} "YN6o_*]
dK]#..
/** Wqe0m_7
* @param currentPage TlC??#
* The currentPage to set. 5:T}C@
*/ GK{~n
publicvoid setCurrentPage(int currentPage){ fo e)_
this.currentPage = currentPage; <-HWs@8#
} JTTI`b2l_
e09QaY
/** "sed{?
* @return X\5EF7:S
* Returns the everyPage. gH0Rd
WX
*/ _8wT4|z5
publicint getEveryPage(){ .K+5k`kd
return everyPage; *rC%nmJwk!
} 7=HpEc
BX2}ar
/** FLQ^J3A,I
* @param everyPage 8O0]hz
* The everyPage to set. NZ-57Ji
*/ } A}Vd:#
publicvoid setEveryPage(int everyPage){ iThf\
this.everyPage = everyPage; |9mGX9q
} C^!~WFy
k>#-NPU$
/** u+ 8wBb5!
* @return oP:/%
* Returns the hasNextPage. Lt{&v^y
*/ uf`/-jY
publicboolean getHasNextPage(){ wpOM~!9R
return hasNextPage; @"afEMd
} \o5/, C
*a`_,Q{x
/** 3*e )D/lm
* @param hasNextPage 21hTun"W
* The hasNextPage to set. pZ 7KWk4
*/ |^O3~!JP(>
publicvoid setHasNextPage(boolean hasNextPage){ e*39/B0S
this.hasNextPage = hasNextPage; JR|P]}
} LGWQBEXw
T/q*k)IoR
/** &_3o 1<
* @return <H|]^An!H
* Returns the hasPrePage. Q.SqOHeJ
*/ JiGS[tR
publicboolean getHasPrePage(){ *s!T$oc
return hasPrePage; Kp[5"N8
} DK<}q1xi
rR(\fX!dg
/** !
;R}=
* @param hasPrePage -IL' (vx
* The hasPrePage to set. {%z5^o1)
*/ 7/bF04~%
publicvoid setHasPrePage(boolean hasPrePage){ la{o<||Aq
this.hasPrePage = hasPrePage; lht :%Ts$
} `91?^T;\F
l(~NpT{=V
/** z[0t%]7l
* @return Returns the totalPage. :(i=> ~O
* XZxzw*Y1J
*/ Wbi12{C
publicint getTotalPage(){ ^F-AZP
/5F
return totalPage; <#lNi.?.
} 6^TWY[z2%
dbfI!4
/** Cp#}x1{
* @param totalPage PBAQ
KQ
* The totalPage to set. 'L2[^iF9
*/ .WlZT-
publicvoid setTotalPage(int totalPage){ |qb-iXW=
this.totalPage = totalPage; &IFXU2t}
}
<^adt
*m
f4^\iZ{`G
} {QT:1U\.
s+a#x(7{
tS[@?qP
1pTQMf a
w=ZK=@
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 5-"aK~@+
Bacmrf
个PageUtil,负责对Page对象进行构造: n;r
W
java代码: lv&y<d;
m!:sDQn{3
03 ;L
/*Created on 2005-4-14*/ S,#UA%V"
package org.flyware.util.page; )"s(;kU!
0;" >.
import org.apache.commons.logging.Log; O_Z
import org.apache.commons.logging.LogFactory; n ZzGak
=]0AZ
/** u@kr;^m
* @author Joa xUDXg*
* <#e!kWGR?
*/ M1XzA
`*
publicclass PageUtil { + $/mh
cnM`ywKW
privatestaticfinal Log logger = LogFactory.getLog ^ ]SU (kY
:Q>{Y
(PageUtil.class); x-SYfvYY
Xl/2-'4
/** 19i [DR
* Use the origin page to create a new page \`YV)"y" ~
* @param page fCi1JH;
* @param totalRecords `^
uX`M/
* @return h5@JS1cY
*/ \PK}4<x}
publicstatic Page createPage(Page page, int u=sZFr@m[
6"La`}B(T8
totalRecords){ 4z,n:>oH
return createPage(page.getEveryPage(), =T|m#*{.L
vtXZ`[D,l)
page.getCurrentPage(), totalRecords); YJBf~0r
} [K `d?&
LS4E.Xdn
/** .Yxf0y?uv
* the basic page utils not including exception iIU>:)i
"ax"k0
handler <*DP G\6Ma
* @param everyPage oqy}?<SQ
* @param currentPage Q5tx\GE
* @param totalRecords e `Tssa+
* @return page O+o_{t\R
*/ ~Q5
i0s%
publicstatic Page createPage(int everyPage, int 8[H)tKf8
jR{Rd}QtQ
currentPage, int totalRecords){ pAc "Wo(Q
everyPage = getEveryPage(everyPage); GD
}i=TK
currentPage = getCurrentPage(currentPage); 3 ~\S]
int beginIndex = getBeginIndex(everyPage, `6y\.6j
axdRV1+s
currentPage); xMo'SpVz:
int totalPage = getTotalPage(everyPage, ?4 lDoP{
B0:/7Ld$Ml
totalRecords); M l9
boolean hasNextPage = hasNextPage(currentPage, J.n-4J#@
i
UW.$1l
totalPage); iFaC[(1@a
boolean hasPrePage = hasPrePage(currentPage); z229:L6"
w&LL-~KI+
returnnew Page(hasPrePage, hasNextPage, HH'5kE0;d
everyPage, totalPage, |1Pi`^
currentPage, s
F3M= uz
w-?Cg8bq<
beginIndex); x-@6U
} ZVz`-hB
f}+8m .g2
privatestaticint getEveryPage(int everyPage){ D2Dk7//82Y
return everyPage == 0 ? 10 : everyPage; `r.
} Mt+ggF.
\FjY;rqfKe
privatestaticint getCurrentPage(int currentPage){ ;.b^A
return currentPage == 0 ? 1 : currentPage; (Kaunp5_`
} K"9V8x3Wg
y`-5/4
privatestaticint getBeginIndex(int everyPage, int CFiO+p&
I07_o"3>qr
currentPage){ )`
90*
return(currentPage - 1) * everyPage; oH kjMqju
} qn~:B7f
5`[B:<E4
privatestaticint getTotalPage(int everyPage, int w1
tg7^(@
Q)}z$h55
totalRecords){ 5tl uS
int totalPage = 0; N!^5<2z@eT
kS$m$
D
if(totalRecords % everyPage == 0) a1#
'uS9W
totalPage = totalRecords / everyPage; ;U$EM+9
else ]$?\,`
totalPage = totalRecords / everyPage + 1 ; 2~2j?\AEd.
FK.Qj P:
return totalPage; P};GcV-
} uM('R;<^
?FwjbG<
privatestaticboolean hasPrePage(int currentPage){ Af7&;8pM
return currentPage == 1 ? false : true; wT-@v,$
} rgXD>yu(
K^+}__;]
privatestaticboolean hasNextPage(int currentPage, q.NvwJ
,N`D{H"F
int totalPage){ M[,G#GO
return currentPage == totalPage || totalPage == z+6%Ya&ls
DU1\ K
0 ? false : true; #gY|T|
} 0@dN$e
6i_dL|c
;B@-RfP
} xl;0&/7e
c %.vI
@mId{w z
My JG2C#R
6pY<,7t0
上面的这两个对象与具体的业务逻辑无关,可以独立和抽象。 Y'v;!11#
y]TNjLpo$
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 7H5t!yk|9
F otHITw[
做法如下: _f@,
>l
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^e7%FX
:T# "bY
的信息,和一个结果集List: ;#Pc^Yzc1
java代码: DB;Nr3x
61{IXx_
F_C_K"[s
/*Created on 2005-6-13*/ *;yn_zg
package com.adt.bo; [*AWCV
/yS/*ET8
import java.util.List; !E|k#c9
Wg
?P"
import org.flyware.util.page.Page; iHL`r1I!
t`y*oRy
/** B!zqvShF
* @author Joa cJ!C=J
*/ qmM%MPv
publicclass Result { @%sr#YqY
_F9O4Q4
private Page page; hCKx%&[^7
('VHL!
private List content;
KL\]1YX
q^k]e{PD
/** @ME
.
* The default constructor Z-B b,8
*/ K{x FhdW
public Result(){ ~^R?H S
super(); U?d4 ^
} Y94/tjt
&33.mdBH
/** .a *^6TC.
* The constructor using fields j}$Up7pW
* wz(D
}N5
* @param page ~M4@hG!
* @param content uepL"%.@7|
*/ ]h6mJ{k
public Result(Page page, List content){ T11;LSD
this.page = page; K0Zq)<
this.content = content; ;&%G)f
} r(::3TF%#q
|U4t 8
/** I{0bsTp;
* @return Returns the content. 9x40
*/ 78i"3Tm)w
publicList getContent(){ Hz6yy*
return content; }th^l*g
} }475c{
[M{EO)
/** 3!V$fl0
* @return Returns the page. p/f!\
*/ b-XC\
public Page getPage(){ wuQ>|\Zs
return page; XgmblNp1
} bb^$]lT'
t|Ipxk.)
/** j$8i!C
* @param content q
T pvz
* The content to set. {UR&Y
*/ j2/3NF5&
public void setContent(List content){ sUP!'Av
this.content = content; @~l?hf
} Jqt&TqX@s
>`@yh-'r
/** fx783
* @param page k-LT'>CWl
* The page to set. M"t=0[0DM:
*/ yU@~UCmja
publicvoid setPage(Page page){ ?$T39U^
this.page = page; 96.z\[0VZ
} qJ|n73yn
} H~P"uYKIZ
pM i w9}
8uO@S*)0
qWzzUM1=
f @cs<x
2. 编写业务逻辑接口,并实现它(UserManager, #!FLX*,
Bw[jrK
UserManagerImpl) l?/.uNw
java代码: 8zRb)B+
%ycCNS
:~2An-V
/*Created on 2005-7-15*/ kH43 T
package com.adt.service; ;Q]j"1c
Gkr^uXNg#
import net.sf.hibernate.HibernateException; ?"aj&,q+
iZy`5
import org.flyware.util.page.Page; L8~nx}UP5
O&:0mpRZ
import com.adt.bo.Result; VhAZncw
w$5N6
/** {xC CUU
* @author Joa 'ZHu=UT7_
*/ WLAJqmC]
publicinterface UserManager { >Ufjmm${
;
-RhI_
public Result listUser(Page page)throws yMNLsR~ rh
LxGE<xj|V%
HibernateException; #c0
dZ
l}DCK
} 4R U1tWQ%
8O]U&A@
4nhe *ip
#&1Y!kbdd
sJlX]\RLQ
java代码: mF>CH]k3
FNDLqf!j
sQA{[l!aj
/*Created on 2005-7-15*/ Z w5\{Z0
package com.adt.service.impl; 9rb/h kX&
.'SXRrn&:C
import java.util.List; 3_atv'I
4Pljyq:
import net.sf.hibernate.HibernateException; <(JsB'TK
xrT_ro8
import org.flyware.util.page.Page; j}R4mh
import org.flyware.util.page.PageUtil; JXlFo3<
I`%=&l[v_5
import com.adt.bo.Result; c4LBlLv4
import com.adt.dao.UserDAO; e^@/Bm+B
import com.adt.exception.ObjectNotFoundException; WRAW%?$
import com.adt.service.UserManager; (%>Sln5hq
9xg_M=72
/** 2`* %NJ
* @author Joa TKc&yAK
*/ ED/-,>[f
publicclass UserManagerImpl implements UserManager { tji,by#E/%
!dLz ?0
private UserDAO userDAO; mm=Y(G[_%y
J1<fE(X
/** JXeqVKF
* @param userDAO The userDAO to set. YF{K9M!
*/ e76@-fg
publicvoid setUserDAO(UserDAO userDAO){ ![5<\
this.userDAO = userDAO; R7KQ-+Zb
} (Df<QC`0v
bq4H4?j
/* (non-Javadoc) 'w%N(N tq
* @see com.adt.service.UserManager#listUser JMOP/]%D
7/vr!tbL`p
(org.flyware.util.page.Page) ?E2k]y6<
*/ P:k(=CzZ@J
public Result listUser(Page page)throws w c%
](0Vm_es
HibernateException, ObjectNotFoundException { ;_i0@@J
int totalRecords = userDAO.getUserCount(); Jb-wvNJu
if(totalRecords == 0) x=B+FIJ
throw new ObjectNotFoundException )
Q=G&
GxZQ{
\
("userNotExist"); l1cBY{3QD
page = PageUtil.createPage(page, totalRecords); LbR/it'}
List users = userDAO.getUserByPage(page); RQ,(?I*8\
returnnew Result(page, users); >`NY[Mn
} b=T+#Jb
z K8#gif@
} ~DZ;l/&Mz7
nu0bJ:0aLd
dr6 dK
i`]M2Q
,:\2Lf
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 l3MbCBX2
qd|*vE
询,接下来编写UserDAO的代码: CES FkAj~
3. UserDAO 和 UserDAOImpl: <(p1
j0_Q
java代码: K=5_jE^e
:=L[kzX
,f?#i%EF&
/*Created on 2005-7-15*/ Ql*/{#$
package com.adt.dao; z3*G(,
Y0B*.H
Ae
import java.util.List; mFF]d
3/rvSR!
import org.flyware.util.page.Page; ?XOeMI
T%a]3
import net.sf.hibernate.HibernateException; j|G-9E
a3c4#'c|D
/** nnGA_7-t
* @author Joa .`'SL''c
*/ Bhq(bV
publicinterface UserDAO extends BaseDAO { NuO>zAu
<uTsXv
publicList getUserByName(String name)throws 3X!~*_iC
$Qy(ed
HibernateException; 8]?1gDS|9O
W=EO=}l#
publicint getUserCount()throws HibernateException; UiZ61lw
}ZmdX^xB
publicList getUserByPage(Page page)throws Y|VzeJC
1M;)$m:
HibernateException; ~$\j$/A8/
1UM]$$:i
}
.V.N^8(:a
dY-a,ch"8p
>Au<y,Tw
78QFaN$
?3Jh{F_+
java代码: 2mlE;.}8
$GO'L2oLwn
0KQ8;&a|
/*Created on 2005-7-15*/ rb tV,Y
package com.adt.dao.impl; 4P~<_]yf
\~)573'
import java.util.List; GO)rpk9
/MU<)[*Ro
import org.flyware.util.page.Page; >(*jbL]p
Nz}Q"6L
import net.sf.hibernate.HibernateException; kx=AX*I
import net.sf.hibernate.Query; 4a @iR2e
twu6z5<!-=
import com.adt.dao.UserDAO; ppnj.tLz;r
p 5o;Rvr
/** 8_,ZJ9l;
* @author Joa V[xy9L[#
*/ }[DAk~
public class UserDAOImpl extends BaseDAOHibernateImpl R]Yhuo9,&n
oPbD9
implements UserDAO { rODKM-7+
\fKE~61
/* (non-Javadoc) `P5"5N\h
* @see com.adt.dao.UserDAO#getUserByName .~U9*5d
l46F3C|
(java.lang.String) y^A$bTQq
*/ QLUe{@ivc
publicList getUserByName(String name)throws $($SQZK&
6'%]6"&M4
HibernateException { e"CLhaT
String querySentence = "FROM user in class +-nQ,
fOV
,pASjFWi
com.adt.po.User WHERE user.name=:name"; piG1&*
Query query = getSession().createQuery $~YuS_sYg
c~'kW`sNV
(querySentence); @iRVY|t/
query.setParameter("name", name); 1}uDgz^
return query.list(); IID(mmy6
L
} J7_H.RPa
!:t9{z{Ixg
/* (non-Javadoc) |i`@!NrFL
* @see com.adt.dao.UserDAO#getUserCount() ;gMh]$|"
*/ "P{&UwMmh
publicint getUserCount()throws HibernateException { u
.2sB6}
int count = 0; W$JA4O>b
String querySentence = "SELECT count(*) FROM :z\f.+MI
dc>y7$2
user in class com.adt.po.User"; itF+6wv~
Query query = getSession().createQuery ?W
n(ciO
:65HMWy.
(querySentence); f$>orVm%.
count = ((Integer)query.iterate().next
m#nxw
cBI)?
()).intValue(); g,:Nzb
return count; eC$v0Gtq
} F&*M$@u5
S0+zq<
/* (non-Javadoc) upDQNG>d
* @see com.adt.dao.UserDAO#getUserByPage C'._}\nX
iW?9oe
(org.flyware.util.page.Page) 1,j9(m2
*/ ~qS/90,
publicList getUserByPage(Page page)throws !T*B{+|
<yS"c5D6
HibernateException { hQm4R]a
String querySentence = "FROM user in class m=MT`-:
BB.TrQM.#
com.adt.po.User"; \Wc/kY3&
Query query = getSession().createQuery >y9o&D