Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 EZ6\pyNB0#
?U\@?@
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 gVM&wo |
t u)kWDk
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 s bl>i
O_yk<
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 z+RA
llbf(!
。 F|,_k%QP
v1s.j2T
分页支持类: n]?KDID;
A2fc_A/a
java代码: v{/z`J!JR
A4lW8&rHI
8.9Z0
package com.javaeye.common.util; tVB9kxtE
f-lM[\ma_
import java.util.List; IYIlab\TZ
1{TmK9U
publicclass PaginationSupport { =0Z^q0.
qhFWQ1W
publicfinalstaticint PAGESIZE = 30; mBQA~@}
T$p!IRPt
privateint pageSize = PAGESIZE; 7r F )fKW
m&o6j>C
privateList items; *]
H8X=[x
N:"S/G>r ;
privateint totalCount; =UGyZV:z5
4<j)1i=A
privateint[] indexes = newint[0]; !fwMkws
!^~
^D<
privateint startIndex = 0; n};:*N!
v
7Nu.2q E
public PaginationSupport(List items, int TuF;>{~}
,".1![b
totalCount){ |ia#Elavo
setPageSize(PAGESIZE); nY]5pOF:
setTotalCount(totalCount); `7v"(
setItems(items); ""0 cw
setStartIndex(0); `\}Ck1o
} 3sh}(
4^3}+cJ7j
public PaginationSupport(List items, int fD^$ y
8
`%%/`Qpj;
totalCount, int startIndex){ iJ&*H)}^
setPageSize(PAGESIZE); K{]9Yo
setTotalCount(totalCount); >s5i
setItems(items); v-
793pr
setStartIndex(startIndex); z(00"ei
} >-%tvrS%
/6K9? /
public PaginationSupport(List items, int 2=\} 0
Nk#[~$Q-1
totalCount, int pageSize, int startIndex){ 3FD6.X>x
setPageSize(pageSize); })?t:zX#*
setTotalCount(totalCount); DJ zJ$Q
setItems(items); F
gi&CJ8Q
setStartIndex(startIndex); HLlp+;CF><
} [:CV5k~xc
|n*nByL/
publicList getItems(){ Xr B)[kQ
return items; t<F*ODn
} 8)Z)pCN
-~Ll;}nZC
publicvoid setItems(List items){ ]AB<OjF1c|
this.items = items; |\#~
} jpGZ&L7i&
F,[GdE;P
publicint getPageSize(){ (uW$ch@2K
return pageSize; "!g}Q*
} vYPZVqF_$
yH9(ru
publicvoid setPageSize(int pageSize){ ]!um}8!}
this.pageSize = pageSize; Em<B9S
} |~+i=y
O`M6=\
publicint getTotalCount(){ [3@Pu.-I+M
return totalCount; eYpK!9
} Z,jR:_p
efT@A}sV
publicvoid setTotalCount(int totalCount){ _~QiQDq
if(totalCount > 0){ 8q}955Nl
this.totalCount = totalCount; 4X}.aZO&b
int count = totalCount / rf ?\s/#OY
~W>3EJghR,
pageSize; A$7j B4
if(totalCount % pageSize > 0) ;4%Co)Rw
count++; 3J3Yt`
indexes = newint[count];
;4:[kv@
for(int i = 0; i < count; i++){ 9I|D"zXn
indexes = pageSize * "mtEjK5
iAl.(j
i; a'Vz|SG
} ?LwBF;Y
}else{ H(QbH)S$6
this.totalCount = 0; ^o LMgz
} -4;$NiB?
} vWs#4JoG
{%&!x;%
publicint[] getIndexes(){ O>KrTK-AV
return indexes; x+Ws lN2a
} CVAX?c{
N 4!18{/2
publicvoid setIndexes(int[] indexes){ Ib&]1ger#=
this.indexes = indexes; +$;#bw)yH
} ]4X08Cm^
5qL;@Y
publicint getStartIndex(){ Qq|c%FZ
return startIndex; 6)h~9iK
} j=up7395
?!Wh ^su-
publicvoid setStartIndex(int startIndex){ fi
tsu"G
if(totalCount <= 0) L!c.1Rf_
this.startIndex = 0; %(X^GL
elseif(startIndex >= totalCount) JeXA*U#
this.startIndex = indexes yt4sg/]:
.',d*H))E7
[indexes.length - 1]; *-vH64e
elseif(startIndex < 0) Fy#7<Hp
this.startIndex = 0; %W8*vSbx
else{ r .`&z
this.startIndex = indexes 4}r.g0L
cHAq[Ebp2!
[startIndex / pageSize]; }~+q S`
} M/abd 7q
} '3uN]-A>D
1G}\IK1+
publicint getNextIndex(){ x,fX mgE
int nextIndex = getStartIndex() + @TraEBJGL
j9r%OZw{
pageSize; 84g8$~M
if(nextIndex >= totalCount) BGrV,h^
return getStartIndex(); ] :.
else r}4
return nextIndex; KX^! t3l6
} t!&p5wJ*Q
!CUy{nV
publicint getPreviousIndex(){ "MPr'3
int previousIndex = getStartIndex() - f5`q9w_c
q |Orv=v
pageSize; @#>YU
if(previousIndex < 0) tE$oV
return0; }I"k=>Ycns
else V2B:
DIpr
return previousIndex; AT-
} 89YG
`
p;<aZ&@O
} 9TUB3x^
mcb|N_#n/
m4@Lml+B,
hbSXa'
抽象业务类 h @2.D|c)g
java代码: [2.;gZj
n48%Uwa,
):st-I!o
/** tL\L4>^7T
* Created on 2005-7-12 7Ml OBPh
*/ +ZJ1> n
package com.javaeye.common.business; 9!,f4&G`
p1']+4r%
import java.io.Serializable;
X?z
CB
import java.util.List; y(yBRR
9`Y\`F#}q
import org.hibernate.Criteria; rebWXz7
import org.hibernate.HibernateException; ZRP[N)Ld$
import org.hibernate.Session; Y?4N%c_;
import org.hibernate.criterion.DetachedCriteria; 0/JTbf. CX
import org.hibernate.criterion.Projections; lbj_if;
import swfjKBfw+g
wqF_hs(O
org.springframework.orm.hibernate3.HibernateCallback; ~0YRWM ;
import Is(ZVI
'EO"0,
org.springframework.orm.hibernate3.support.HibernateDaoS 2&0#'Tb
R,8460e7
upport; =kBWY9:$,
C[[:/X(c
import com.javaeye.common.util.PaginationSupport; 3a?dNwM@
.|/VD'xV"
public abstract class AbstractManager extends =GL^tAUJ
1$nuh@-ys
HibernateDaoSupport { iHk/#a
=p \eh?^
privateboolean cacheQueries = false; %&M*G@j
q\d/-K
privateString queryCacheRegion; 9)S,c=z83
$p\ 0/
publicvoid setCacheQueries(boolean }_h2:^n
"
XlXu
cacheQueries){ 3z!^UA>q
this.cacheQueries = cacheQueries; **~1`_7~*
} P] Xl
XSktbk
publicvoid setQueryCacheRegion(String LYMb)=u]
[W8?ww%qT
queryCacheRegion){ w^)_Fk3
this.queryCacheRegion = qFwAzW;"
!4}Wp.
queryCacheRegion; HEs .pET\
} #OsUF,NU
-f=4\3y3p
publicvoid save(finalObject entity){ g)=-%n'RoE
getHibernateTemplate().save(entity); >$_@p(w
} kp8kp`S7
4=ZN4=(_[
publicvoid persist(finalObject entity){ <*+Y]=
getHibernateTemplate().save(entity); qR^i5JH}u
} f"d4HZD^
L r9z~T:ED
publicvoid update(finalObject entity){ :pGgxO% q
getHibernateTemplate().update(entity); |K'7BK_^J
} D)J'xG_<O
f=Kt[|%'e
publicvoid delete(finalObject entity){ 10ZL-7D#m
getHibernateTemplate().delete(entity); mO@Sl(9
} VR vX^w0
S!R:a>\
publicObject load(finalClass entity, f= 33+8I
m8z414o
finalSerializable id){ %P`|kPW1
return getHibernateTemplate().load l/6(V:
M*<Bp
(entity, id); W-ol*S
} Q_FL8w9D~8
Vv.q{fRvYB
publicObject get(finalClass entity, Y@'ahxF
`E5vO1Pl
finalSerializable id){ KZI-/H+
return getHibernateTemplate().get 3.?B')
E>N L/[1d
(entity, id); lKLb\F%
}
"xE;IpO[
Ov|Uux
publicList findAll(finalClass entity){ m.>y(TI
return getHibernateTemplate().find("from )Zit6I
.ot[_*A.FD
" + entity.getName()); m*\XH
DB
} RRJN@|"
^A;(#5A]7
publicList findByNamedQuery(finalString h2mU
m95;NT1N/g
namedQuery){ Kv#TJn
return getHibernateTemplate =d1R9O
XV0t
8#T2
().findByNamedQuery(namedQuery); 42 &m)
} %^<A`Q_
S0mF%"
publicList findByNamedQuery(finalString query, Yc~c(1VRz
*egAx
finalObject parameter){ H^0`YQJ3
return getHibernateTemplate FW!1 0K?
82~ZPZG
().findByNamedQuery(query, parameter); OojQG
} D(^ |'1
vV /fTO
publicList findByNamedQuery(finalString query, `yWWX.`
^*+-0b;[G
finalObject[] parameters){ f*GdHUZ*
return getHibernateTemplate S0-/9h
h&6t.2<e
().findByNamedQuery(query, parameters); ${w\^6&
} *Q:EICDE7
jthGNVZ
publicList find(finalString query){ O{44GB3
return getHibernateTemplate().find q
NE(@at
.5YIf~!59
(query); 2:D1<z6RQ
} b}5hqIy
'3V?M;3|K
publicList find(finalString query, finalObject bhc
.UmH
1
Ll<^P
parameter){ {;Ispx0m
return getHibernateTemplate().find cb9q0sdf
Q.`O;D}x
(query, parameter); 09C[B+>h
} qaN%&K9F8
|h75S.UY
public PaginationSupport findPageByCriteria Tq=OYJq5U
SPU_@ Pk
(final DetachedCriteria detachedCriteria){ VS_xC$X!S
return findPageByCriteria w`F4.e
$ h<l
(detachedCriteria, PaginationSupport.PAGESIZE, 0); x1nqhSaD
} c=A)_ZFg
/?Fa<{
public PaginationSupport findPageByCriteria ~R\Z&oQ
4'ymPPY
(final DetachedCriteria detachedCriteria, finalint iPoDesp
^GN |}W
startIndex){ pX/,s#dY>
return findPageByCriteria X1{U''$
K
}^Kye23
(detachedCriteria, PaginationSupport.PAGESIZE, STH?X]
/
Kv26rY8Q
startIndex); nkvkHh
} _&
qM^
{=GWQn6cc
public PaginationSupport findPageByCriteria <!M ab}
6su^yt
(final DetachedCriteria detachedCriteria, finalint -H;p +XAY
-Y"'=zkO
pageSize, @(_M\>!%M
finalint startIndex){ auP6\kpMe
return(PaginationSupport) GMO|A.bzzN
(0/)vZc
getHibernateTemplate().execute(new HibernateCallback(){ drZ1D s
publicObject doInHibernate V`MV_zA2
xX]92Q
(Session session)throws HibernateException { }R -azN;
Criteria criteria = EO[UezuU
MGzuQrl{H
detachedCriteria.getExecutableCriteria(session); gAWrn^2L5
int totalCount = Yh}F
$5;RQNhXh
((Integer) criteria.setProjection(Projections.rowCount BXf.^s{H
^7l^/GSO
()).uniqueResult()).intValue(); NFQR
criteria.setProjection "Lp"o
,wvzY7%
(null); L?c7M}vV
List items = ,`lVB#|
?m$7)@p
criteria.setFirstResult(startIndex).setMaxResults .g6DKjy>
M~1 n#
(pageSize).list(); x>yeF,q1
PaginationSupport ps = 8 O5@FU
3
_4VS.~}/R
new PaginationSupport(items, totalCount, pageSize, + ^9;<>P
i+z;tF`
startIndex); 0$9I.%4jAJ
return ps; CdN,R"V0$@
} FOU^Wcop%
}, true); mjd9]HgN
} D>c-h)2|
&sRjs
public List findAllByCriteria(final E'g2<k
]EzX$T
DetachedCriteria detachedCriteria){ ?/,sKF74i
return(List) getHibernateTemplate m8|&z{
H' [#x2
().execute(new HibernateCallback(){ <2Qh5umQ
publicObject doInHibernate +I+7@Xi Z
*\i<+~I@l
(Session session)throws HibernateException { _\P9~w
`
Criteria criteria = 8'(|1
|# zznT"
detachedCriteria.getExecutableCriteria(session); +I?T|Iin
return criteria.list(); u$Za hN!
} D*oJz3[
}, true);
e8TJ =}\
} /_rg*y*
f;(]P
public int getCountByCriteria(final AF
qut
nFn@Z'T$N
DetachedCriteria detachedCriteria){ /!*gH1s
Integer count = (Integer) b7:B[7yK.x
I+Q`i:\,q
getHibernateTemplate().execute(new HibernateCallback(){ o9:GKc
publicObject doInHibernate F+`DfI]/m
+C{ %pF
(Session session)throws HibernateException { %DQ.f*%
Criteria criteria = o >=YoG
7x%0^~/n
detachedCriteria.getExecutableCriteria(session); Xj\SJ*
return o'3t(dyyH
i8`&XGEd
criteria.setProjection(Projections.rowCount 3huTT"G
bm{L6D E
()).uniqueResult(); |xTf:@hgHf
} l/BE~gdl
}, true); U~SOHfZ%(
return count.intValue(); =%:mZ@x'
} }@pe`AF^
} mySm:ToT
1f 0"z1
G}tq'#]E{z
2S1wL<qP
xi6Fs, 2S
lrSo@JQ
用户在web层构造查询条件detachedCriteria,和可选的 9oteQN{9
^ftZ{uA
startIndex,调用业务bean的相应findByCriteria方法,返回一个 6N4/p=lE
b|c?xHF}K
PaginationSupport的实例ps。 :v k+[PzJ
=sP6
ps.getItems()得到已分页好的结果集 g5)f8k0+ t
ps.getIndexes()得到分页索引的数组 Aa5IccR
ps.getTotalCount()得到总结果数 ;a+>><x]
ps.getStartIndex()当前分页索引 \^wI9g~0
ps.getNextIndex()下一页索引 W39R)sra
ps.getPreviousIndex()上一页索引 ms=Ilz
saH +C@_,
B
0%kq7>g
=;{vfjj
n_@YKz;8
/Xi:k
Kfc(GL?
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 @|&P#wd.u
(U/xpj}
,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 ;bd\XHwMUP
63QSYn,t
一下代码重构了。 a$I;
L
$S$%avRX
我把原本我的做法也提供出来供大家讨论吧: Aa&3x~3+
5Mb1==/R
首先,为了实现分页查询,我封装了一个Page类: :~ 3/
java代码: |WeLmy%9
,\5]n&T;r
Vkex&?>v$
/*Created on 2005-4-14*/ bw{%X
package org.flyware.util.page; >RxZ-.,a
T7YzO,b/
/** VGBL<X
* @author Joa }k}5\%#li5
* J4te!,
*/ 8zz-jkR
publicclass Page { 0Bn$C,-
MB\vgKY
/** imply if the page has previous page */ :Ke~b_$Uy-
privateboolean hasPrePage; xH\'gli/
\O?#gW\tR
/** imply if the page has next page */ uJG^>B?`b
privateboolean hasNextPage; LX
j Tqp'
?x]T&S{
/** the number of every page */ <;x+?j
privateint everyPage; dL")E|\\k
~s{$&N
/** the total page number */ oZ%t! Fl1
privateint totalPage; J6Mm=bO5
c0Jf
/** the number of current page */ u=#!je
privateint currentPage; C,-V>bx g
1K,bmb xRt
/** the begin index of the records by the current qO>BF/)a(
2:i`,
query */ *D]/V U
privateint beginIndex; kaUH#;c>_
4 !~JNO
;4XX8W1
/** The default constructor */ XLFJ?$)Tro
public Page(){ ~@R=]l"
%@*diJ
} hdN3r{
jKQnox+=
/** construct the page by everyPage T:wd3^.CG
* @param everyPage eUqsvF}l!
* */ &cDnZ3Q;
public Page(int everyPage){ pz?.(AmU\
this.everyPage = everyPage; sJ?Fque
} 9ZG.%+l
xgJ2W_
/** The whole constructor */ vC\]7]mC
public Page(boolean hasPrePage, boolean hasNextPage, `
M"Zq
-CY?~WL&
.he%a3e
int everyPage, int totalPage, 5nqj
int currentPage, int beginIndex){ 50rq}-
this.hasPrePage = hasPrePage; uxVXnQQ
this.hasNextPage = hasNextPage; yXrFH@3
this.everyPage = everyPage; hig^ovF
this.totalPage = totalPage; =5^L_, 4c2
this.currentPage = currentPage; a+zE`uY
this.beginIndex = beginIndex; @<},- u
} RhbYDsG
*;+lF
/** Dw;L=4F
|
* @return Vjj30f
* Returns the beginIndex. 62%.ddM4
*/ 6E@r9U
publicint getBeginIndex(){ sqac>v
return beginIndex; &^qD<eZ!Eq
} #)=P/N1
lGjmw"/C
/** Hc^b}A y7
* @param beginIndex lh~!cOm\=E
* The beginIndex to set. T
-C2V$1
*/ T\8|Q@
publicvoid setBeginIndex(int beginIndex){ ,+,""t
this.beginIndex = beginIndex; 49_b)K.tB
} ] 2FS=
"]5]"F 4]
/** hRxR2
* @return )"A+T&
* Returns the currentPage. C#>c(-p>RC
*/ zWB>;Z}
publicint getCurrentPage(){ N}VKH5U|
return currentPage; 3HFsR)
} RH6qi{)i!
98Pt&C? -B
/** a,M7Bbx
* @param currentPage <G\q/!@_
* The currentPage to set. O)`R)MQ)
*/ 2@:Go`mg
publicvoid setCurrentPage(int currentPage){ 5"^$3&)
this.currentPage = currentPage; 6/.-V1*O
} ?$pp%
Bz9!a k~4
/** 8_8R$=V
* @return ?J6J#{LRd
* Returns the everyPage. Z!~~6Sq
*/ yXR$MT+ ~
publicint getEveryPage(){ !4]wb!F
return everyPage; y!mjZR,&
} JQi)6A?J
vDv:3qN7(
/** a0CmCv2#
* @param everyPage ArbfA~jXB
* The everyPage to set. cZZ-K?_
*/ ISa2|v;M
publicvoid setEveryPage(int everyPage){ vitmG'|WG
this.everyPage = everyPage; ,>`wz^z
} D$I7Gz,w{
QP >P
/** ~H7m7
* @return .1[K\t)2
* Returns the hasNextPage. :JxShF:M
*/ m:)v>v u
publicboolean getHasNextPage(){ xQ^zX7
return hasNextPage; $3W[fC
} k^S=i_ U
oOmPbAY
/** qOV#$dkY
* @param hasNextPage ,N?~je.
* The hasNextPage to set. #fRhG^QKp
*/ 4nXS}bW f
publicvoid setHasNextPage(boolean hasNextPage){ 3!,XR\`[
this.hasNextPage = hasNextPage; }R;.~F
} 3/@7$nV
bQrH8)
/** ]j~V01p/e
* @return 5|9,S
* Returns the hasPrePage. SLD%8:Zn
*/ ]xCJ3.9
publicboolean getHasPrePage(){ -s,^_p{H
return hasPrePage; 25::z9i
} tl
(2=\
KArR.o }
/** _K_!(]t
* @param hasPrePage #78p#E
* The hasPrePage to set. jY('?3
*/ fOdkzD,
publicvoid setHasPrePage(boolean hasPrePage){ $[by)
this.hasPrePage = hasPrePage; B=jJ+R
} 0;#%KC,
SirjWYap
/** Wr a W
* @return Returns the totalPage. C;1A$]bk
* e>#*$4tg
*/ w9SPkPkYE
publicint getTotalPage(){ VL?ubt<
return totalPage; SWNi@
} |ITp$_S
`M6!V
/** (Ub=sC
* @param totalPage N&]v\MjI62
* The totalPage to set. lQ<2Vw#Yl
*/ +\fr3@Yc
publicvoid setTotalPage(int totalPage){ =!*e; L
this.totalPage = totalPage; j#f+0
} C\ZL*,%}
2%m H
} 0~iC#lHO
ryB^$Kh,,
eB%KXPhMm
AE={P*g
8V`NQS$
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 9TIyY`2!
h3Nwxj~E
个PageUtil,负责对Page对象进行构造: %[u6<
java代码: Kyt.[" p
!hrXud=#"
XI}
C|]#
/*Created on 2005-4-14*/ GbFLu`I u
package org.flyware.util.page; : ^F+mQN
5x(`z
import org.apache.commons.logging.Log; AjKP -[
import org.apache.commons.logging.LogFactory; 9c1g,:8\
=Mzg={)v
/** cv=nGFx6
* @author Joa l"5$6h
* I= G%r/3
*/ ZR.1SA0x?O
publicclass PageUtil { ng0IRJ:3
w,bILv)
privatestaticfinal Log logger = LogFactory.getLog QM\vruTB
D>+&= 5{
(PageUtil.class); 9f+|m9~2
w<3}(1
/** ZM K"3c9
* Use the origin page to create a new page }zY)H9J~
* @param page #s$b\"4
* @param totalRecords q#:,6HDd
* @return ZF"f.aV8)
*/ WPygmti}Be
publicstatic Page createPage(Page page, int jJkM:iR
D9zw' RY
totalRecords){ rlT[tOVAY
return createPage(page.getEveryPage(), XSyCT0f08
lhw]?\
page.getCurrentPage(), totalRecords); QZB2yK3]h
} 9yH95uaDF
#~3x^4Y
/** \{AxDk{z#
* the basic page utils not including exception M>D 3NY[,
|RDmY!9&
handler T)&J}^j
* @param everyPage f#_ XR
* @param currentPage kT@RA}
* @param totalRecords ,DK |jf
* @return page ?Z0T9e<
*/ /=w9bUj5v
publicstatic Page createPage(int everyPage, int 9_h3<3e
5!$m3j_,]?
currentPage, int totalRecords){ DQ :w9
everyPage = getEveryPage(everyPage); )f-u x5
currentPage = getCurrentPage(currentPage); 0#lw?sv
int beginIndex = getBeginIndex(everyPage, _QbLg"O
@[#U_T- I
currentPage); ;>QED
int totalPage = getTotalPage(everyPage, Rq gH,AN
<h^'x7PkW5
totalRecords); VgtWT`F.I
boolean hasNextPage = hasNextPage(currentPage, 1@q~(1-o
vCyvy^s-I
totalPage); daf$`
boolean hasPrePage = hasPrePage(currentPage); GE]fBg
&sR=N60n
returnnew Page(hasPrePage, hasNextPage, sfNXIEr^
everyPage, totalPage, AVVL]9b_2
currentPage, Mez;DKJ`
&,4]XT
beginIndex); ^wPKqu)^
} lwYk`'
nv1'iSEeOl
privatestaticint getEveryPage(int everyPage){ oJe9H <
return everyPage == 0 ? 10 : everyPage; P1;T-.X~&
} g9|B-1[
[/hS5TG|7
privatestaticint getCurrentPage(int currentPage){ #c@Dn.W
return currentPage == 0 ? 1 : currentPage; ^prseO?A
} 6kuN)
&o{I9MD
privatestaticint getBeginIndex(int everyPage, int RmxgCe(2a
pW7vY)hj
currentPage){ K&0op 4&
return(currentPage - 1) * everyPage; [RCUP.
} Gc>bli<-
ez=$ ]cln
privatestaticint getTotalPage(int everyPage, int 5%"${ywI
-NtT@ +AE
totalRecords){ _5%SYxF*y
int totalPage = 0; jK/2n}q&]
{[G2{ijRz
if(totalRecords % everyPage == 0) ]vJZ v"ACn
totalPage = totalRecords / everyPage; O&l(`*P
else *')BP;|V`
totalPage = totalRecords / everyPage + 1 ; p8K4^H
hm3,?FMbq
return totalPage; O=LS~&=,
} jIJVl \i]
4v9zFJ<Z
privatestaticboolean hasPrePage(int currentPage){ TU$PAwn=
return currentPage == 1 ? false : true; [tsi8r=T
} LO]D
XW 9
A!Zjcp|
privatestaticboolean hasNextPage(int currentPage, V#[I/D
UMwB. *
int totalPage){ @%&;V(
return currentPage == totalPage || totalPage == r/1:!Vu(
gS4zX>rqe
0 ? false : true; A`<#}~A
} F+PIZ%
hLFf
GHj1G,L@\
} *@o@>
7Ipt~K}
0}Rxe
\]GO*]CaV
B!GpD@U
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。 F{)YdqQ
v1<gNb)`
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 `bu3S}m7
Af1izS3
做法如下: Cnd70tbD )
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 J"QXu M
_H}y7
的信息,和一个结果集List: %])-+T
java代码: y[[f?rxz>
txQyHQ)@
Z
l.}=
/*Created on 2005-6-13*/ DLcfOOn1I
package com.adt.bo; JPfNf3<@My
wVkms
import java.util.List; IK5FSN]s/
L,!?'.*/]
import org.flyware.util.page.Page; d=V4,:=S
W[PZQCL}K)
/** @Tb
T
* @author Joa :0IxnK(r&
*/ _'<V<OjVM!
publicclass Result { g0Qg]F5D~
-
{<`Z
private Page page; !O
F#4N
~r;da 9
private List content; 5MV4N[;
_d6mf4M]5
/** }MP2)6
* The default constructor FP<RoA?W
*/ KJWYG^zI
public Result(){ 9+@"DuYc6
super(); xal,j*
} 75i
M_e\
^Dh j<_
/** ANtp7ad
* The constructor using fields X<@yt HBv
* 6GX'&z
* @param page Ag}V>i'
* @param content qd{o64;|
*/ pcXY6[#N
public Result(Page page, List content){ HX\@Qws
this.page = page; mNN,}nHu
this.content = content; ZiM#g1;
} AE!WYE
'7o'u]
/** #@H{Ypn`
* @return Returns the content. '&Ox,i]t
*/ z"o;|T:
publicList getContent(){ b7R#tT
return content; fHvQ 9*T
} f^](D'L?D
WS9n.opl}
/** Ug^C}".&
* @return Returns the page. IcZ_AIjlk
*/ ^% BD
public Page getPage(){ S`2M QL
return page; .vNfbYH(
} ka{9{/dz3
1 Uz'=a
/** !OWVOq8
* @param content hKtOh
* The content to set. *E0+!
*/ hRb
k-b
public void setContent(List content){ dvxD{UH
this.content = content; /-z_"G
} !_E E|#`n
Le9r7O:
/** 1~8F&
* @param page z
* The page to set. 6yk
*/ 5Zs"CDU
publicvoid setPage(Page page){ 8B;`9?CI
this.page = page; 7p3 ;b"'
} (ii 5p nq
} }#zE`IT
nQK@Uy5Yr
;hF >iw
B)
&BqZ&
0uzis09
2. 编写业务逻辑接口,并实现它(UserManager, HP|,AmVLl
=sRd5aMs
UserManagerImpl) I@cKiB
java代码: E#Ynn6
i_g="^
S$W
*i@x?
/*Created on 2005-7-15*/ RL~|Kr<7J
package com.adt.service; #W
1`vke3
[UNfft=K3P
import net.sf.hibernate.HibernateException;
j^KM
As@~%0 S
import org.flyware.util.page.Page; ~B>I?j
%r6LU<;1@
import com.adt.bo.Result; F<BhN+U
%s$_KG !&
/** n-,~Bp
[
* @author Joa ]@l~z0^|[_
*/ L6BHh_*E
publicinterface UserManager { "V~U{(Z
W()FKP\??!
public Result listUser(Page page)throws >IfJ.g"
25ul,t_Du
HibernateException; W#e:r z8=
Bp^>R`,
} '\1%%F7
;5my(J*b
!f)'+_d
~J)4 (411
sC
]&Qr_
java代码: x0.&fCh%
'Twi
@I
M(Jf&h4b
/*Created on 2005-7-15*/ tt|U,o
package com.adt.service.impl; 1|/2%IDUI
po=*%Zs*T
import java.util.List; ++,mM7a
cWFvYF
import net.sf.hibernate.HibernateException; (4ow0}1
G2a fHL<
import org.flyware.util.page.Page; Iay7Fkv
import org.flyware.util.page.PageUtil; G D[~4G
:KX/`
import com.adt.bo.Result; XIBw&mWf
import com.adt.dao.UserDAO; zF)_t S
import com.adt.exception.ObjectNotFoundException; m>:%[vm
import com.adt.service.UserManager; ddnWr"_
Uj k``;
/** 5F^,7A4I0
* @author Joa NWCnt,FlY
*/ xO1d^{~^^
publicclass UserManagerImpl implements UserManager { 6J%SkuxR
,)]ZD H
private UserDAO userDAO; \`>Y
t T-]Vj.
/** "j$}'uK<
* @param userDAO The userDAO to set. [FiXsYb.8
*/ k%In
publicvoid setUserDAO(UserDAO userDAO){ JB%6G|Z
this.userDAO = userDAO; MM'<uy
} Om}&`AP};
7Fy^K;V"
/* (non-Javadoc) 9D<^)ShY
* @see com.adt.service.UserManager#listUser s\7|b:y&
F,:F9r?l,H
(org.flyware.util.page.Page) zztW7MG2lQ
*/ GrM~%ng
public Result listUser(Page page)throws =[1W.Zt
c
|C12b[
HibernateException, ObjectNotFoundException { KOF! a
int totalRecords = userDAO.getUserCount(); VKik8)/.
if(totalRecords == 0)
r.K4<ly-N
throw new ObjectNotFoundException Fof_xv9
G)< k5U4
("userNotExist"); \re.KB#R
page = PageUtil.createPage(page, totalRecords); @
K@~4!
List users = userDAO.getUserByPage(page); }FM<uBKW
returnnew Result(page, users); Ccc6 ko_
} HNh=igu
;quGy3
} "9WP^[
IZ2#jSDn
uxh4nyE
k*M{?4
YRYrR|I
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 Ok:@F/ v
Ix *KL=MG
询,接下来编写UserDAO的代码: 'HqAm$V+
3. UserDAO 和 UserDAOImpl: >_F&oA#
java代码: AOWI`
t?0=;.D
Nc"h8p?
/*Created on 2005-7-15*/ ZVGw@3
package com.adt.dao; $%t{O[(
fi?[ e?|c@
import java.util.List; %pwm34
?QuFRl,ZJ
import org.flyware.util.page.Page; xxV{1, H2
+=}%
7o
import net.sf.hibernate.HibernateException; W6_3f-4g
omRd'\ RO
/** fptW#_V2
* @author Joa iww h,(
*/ 6iC}%eU
publicinterface UserDAO extends BaseDAO { 2j"%}&
9CN /v
publicList getUserByName(String name)throws 9J|YP}%
k~vmHb
HibernateException; Gg;#U`
KBJ|P^W5j
publicint getUserCount()throws HibernateException; uj:w^t ][
Y]Fq)-
publicList getUserByPage(Page page)throws !^m5by
_nRshTt`V&
HibernateException; K^w9@&