Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 GpeW<%
\P
pY"WW0p"C
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 '6dVe2V
"CJ~BJI%
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 _Hv+2E[4Z
Kd5'2"DI
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 w+R/>a(]
2F:qaz
。 u;_h%z5K
>9&31wA_
分页支持类: u[b |QR=5
(4+P7Z,Nc
java代码: E{|B&6$[}
,IjZQ53q~
qgrJi +WZ
package com.javaeye.common.util; Qu61$!
nnv|GnQST
import java.util.List; ;t{q]"? W
o6[.$C
publicclass PaginationSupport { {|?^@
'[{<aEo
publicfinalstaticint PAGESIZE = 30; Food<(!.>
^<CVQ8R7
privateint pageSize = PAGESIZE; `pfIgryns
Gaix6@X6'
privateList items; A`Z/B[)
M/?,Qii
privateint totalCount; XDemdMy$
Z10Vx2B
privateint[] indexes = newint[0]; 3PNdc}h
pmNy=ZXx
privateint startIndex = 0; 0kkDlWkzo
xs{pGQ6Q
public PaginationSupport(List items, int f jx`|MJ
WA`A/`taT
totalCount){ :-1|dE)U
setPageSize(PAGESIZE); D@bGJc0
setTotalCount(totalCount); .G O0xnm
setItems(items); a `R%\@1
setStartIndex(0); dht0PZdx?
} =u<:'\_
_ox+5?>
public PaginationSupport(List items, int yq%5h[M
u.GnXuax
totalCount, int startIndex){ $H)^o!
setPageSize(PAGESIZE); 4@PA+(kvS
setTotalCount(totalCount); dJ"M#X!Zu
setItems(items); '#'noB;,
setStartIndex(startIndex); HuevDy4
} `L'g<VK;
.{V"Gn9!
public PaginationSupport(List items, int $'J3
/C7
jc5[r;#
totalCount, int pageSize, int startIndex){ "?8)}"/f
setPageSize(pageSize); CvoFt=c$jE
setTotalCount(totalCount); npdljLN
setItems(items); %_OjmXOfe
setStartIndex(startIndex); 'C[tPP
} 4ijtx)SA
:$WO"HfMSn
publicList getItems(){ 'FErk~}/4s
return items; Y sM*d
} |b
SI}s
publicvoid setItems(List items){ #a8kA"X
this.items = items; .IeO+RDQ
} ^D+J
k8
dHnCSOM<
publicint getPageSize(){ 6_j |@
return pageSize; 1MN!
} n#(pT3&
0,%{r.\S
publicvoid setPageSize(int pageSize){ KF.{r
this.pageSize = pageSize; y\?ey'o
} /I%z7f91O
R/vHq36d
publicint getTotalCount(){ l(t&<O(m9
return totalCount; AC,RS7
} }%|ewy9|CW
J&xZN8jW
publicvoid setTotalCount(int totalCount){ M8/a laoT
if(totalCount > 0){ 76nH)^%l<
this.totalCount = totalCount; GK@OdurAR
int count = totalCount / 8u[_t.y4m
./YR8 #,
pageSize; }HgG<.H>
if(totalCount % pageSize > 0) "aJHCi~l
count++; UL+Txc
indexes = newint[count]; 5hrI#fpOR
for(int i = 0; i < count; i++){ H1bR+2s
indexes = pageSize * I3t5S;_8
:`bC3Mr
i; +jLy>=u
} G@8)3 @
}else{ H[=\_X1o(
this.totalCount = 0; 8x{Owj:Q
} .biq)Le
} 9K+>;`
2\xw2VQ@P
publicint[] getIndexes(){ /v{+V/'+
return indexes; &2tfj(ms
} TKDG+`TyZ
&\h7E
publicvoid setIndexes(int[] indexes){ c!6D{(sfh
this.indexes = indexes; /5@YZ?|#2
} &.)=>2
nS+Rbhs
publicint getStartIndex(){ 9[0iIT$q$
return startIndex; ?cV,lak
} 'a~@q~!
yM_/_V|G
publicvoid setStartIndex(int startIndex){ A}9Z%U
if(totalCount <= 0)
WTSh#L
this.startIndex = 0; aacy5E
elseif(startIndex >= totalCount) }`tSRB7
this.startIndex = indexes ;+Jx,{)
) c@gRb~
[indexes.length - 1]; 5zl+M`
elseif(startIndex < 0) ;4F6
$T'I
this.startIndex = 0; 7)Toj
else{ )qWwh)\;!
this.startIndex = indexes pKSCC"i&j
r.C6`
a
[startIndex / pageSize]; Z\!,f.>g
} D!j/a!MaKk
} k&Pt\- 9on
&YhAB\Rw
publicint getNextIndex(){ [&lK.?V)
int nextIndex = getStartIndex() + il0K ^i
^z?b6kTC
pageSize; !cW rB9
if(nextIndex >= totalCount) opcanl9pSW
return getStartIndex(); Hm-#Mpw
else Xoj"rR9|
return nextIndex; IiYL2JS;t|
} 1T^WMn:U
-U|c~Cqc
publicint getPreviousIndex(){ Al$z.i?R
int previousIndex = getStartIndex() - ipSMmpB
+H-=`+,
pageSize; ]!hjKu"
if(previousIndex < 0) ]S2rqKB
return0; i
;FKnK
else .3
EZk86
return previousIndex; BQu
|qrq
} o[C^z7WG0
O
NabL.CV
} hx$]fvDevD
yV^Yp=f_
}M07-qIX{
d4Uw+3ikW
抽象业务类 *!5CL'
java代码: MAa9JA8kw)
E7uIur=g!
V?mP7
/** ni;_Un~
* Created on 2005-7-12 K~(RV4oF8B
*/ {oQs*`=l>
package com.javaeye.common.business; 8}QM~&&.
.:S/x{~
import java.io.Serializable; l}nV WuD
import java.util.List; %4~"$kE
9{Hs1MD[
import org.hibernate.Criteria; zJDHDr
import org.hibernate.HibernateException; 4n,&,R r#
import org.hibernate.Session; G]lGoa}]`u
import org.hibernate.criterion.DetachedCriteria; w2LnY1A
import org.hibernate.criterion.Projections; osp~)icun
import k+QGvgP[4@
6H#:rM
org.springframework.orm.hibernate3.HibernateCallback; wE
.H:q4&
import Ev fvU:z
x ;DoQx
org.springframework.orm.hibernate3.support.HibernateDaoS _){|/Zd
g/GI'8EMj
upport; y0%@^^-Ru
} z'Jsy[s
import com.javaeye.common.util.PaginationSupport; De$~ *2
$QJ3~mG2
public abstract class AbstractManager extends *i"9D:
xm m,-u
HibernateDaoSupport { o/AG9|()4
@@Ib^sB%
privateboolean cacheQueries = false; ?9 huuJs7
AR |4^
privateString queryCacheRegion; 91R#/i
Nd(,oXa~
publicvoid setCacheQueries(boolean !HTOE@
{gD ED
cacheQueries){ `d <`>
this.cacheQueries = cacheQueries; Q{/z>-X\x
} )%C.IZ_s2
4$-R|@,|_
publicvoid setQueryCacheRegion(String I;4quFBlMu
gawY{Jr8I
queryCacheRegion){ !j!w$
this.queryCacheRegion = Y9.3`VX
,%pCcM)
queryCacheRegion; [@i:qB>B
} >.<VD7p
6[m~xegG
publicvoid save(finalObject entity){ %"
iX3
getHibernateTemplate().save(entity); }dc0ZRKgx
} A
mZXUb
!W}sOK7#
publicvoid persist(finalObject entity){ \h
~_<)
getHibernateTemplate().save(entity); N{Sp-J>
} @IG's-
!)a_@d.;i
publicvoid update(finalObject entity){ )fJ"Hq
getHibernateTemplate().update(entity); CJ<nUIy'z
} y|LHnNQ
/^=1]+_!
publicvoid delete(finalObject entity){ :Xw|v2z%3
getHibernateTemplate().delete(entity); QK_5gD`$a,
} VEps|d3,,
|\(uO|)ju
publicObject load(finalClass entity, a`wjZ"}'[
3kxo1eb
finalSerializable id){ Sca"LaW1
return getHibernateTemplate().load Ts!'>_<Je
')xOL=w
(entity, id); L;V8c
} I%d=c0>%
Q<sqlh!h
publicObject get(finalClass entity, J2O,wb)U
KjGu !B
finalSerializable id){ tLzLO#/n
return getHibernateTemplate().get eRUdPPq_d
<Jgcj4D
(entity, id); YZ~MByu
} #Y5k/NPg
GvVkb=="
publicList findAll(finalClass entity){ 7}iv+rQ
return getHibernateTemplate().find("from J;& y?%{@5
::Zo` vP
" + entity.getName()); 12`u[O}\}-
} >axeUd+@i
w$
8r<?^3
publicList findByNamedQuery(finalString cSt)Na~C
/
namedQuery){ 9=j9vBV
return getHibernateTemplate \ eHOHHAGW
ZSf &M
().findByNamedQuery(namedQuery); 6]7csOE
} .SC*! ,
xs= ~N
publicList findByNamedQuery(finalString query, 7I3_$uF
CX]1I|T5
finalObject parameter){ ,X!6|l8
return getHibernateTemplate Q}#Je.;
|=;hQ2HyF
().findByNamedQuery(query, parameter); 15ailA&(Qm
} fRS;6Jc
#xtH6\X
publicList findByNamedQuery(finalString query, xXJ*xYn"}
xsa`R^5/c
finalObject[] parameters){ FWbp;v{
return getHibernateTemplate +O/b[O'0
2^r~->
().findByNamedQuery(query, parameters); 5FOMh"!z\
} bZxN]6_
x2!R&q8U>
publicList find(finalString query){ K P]ar.
return getHibernateTemplate().find hYoUZ'4
jOGdq;|
(query); kmC@\xTp
} aAjl
58
.`Rt
publicList find(finalString query, finalObject z +MH co"
lu.]R>w
parameter){ +a5F:3$
return getHibernateTemplate().find O`Tz^Q/D
a=2.Y?
(query, parameter); Vk{;g
} fo ~uI(rk
wm~7`&
public PaginationSupport findPageByCriteria |62` {+
V'vWz`#
(final DetachedCriteria detachedCriteria){ `'1g>Ebk0
return findPageByCriteria d]DV\*v
5cPyi/
(detachedCriteria, PaginationSupport.PAGESIZE, 0); P%2v(
} 5%}e j)@
^oi']O
public PaginationSupport findPageByCriteria W,4!"*+
vT?^#
(final DetachedCriteria detachedCriteria, finalint NY7yk3
?i _ACKpw
startIndex){ sF{~7IB
return findPageByCriteria /DAR'9@h
,@ '^3u
(detachedCriteria, PaginationSupport.PAGESIZE, G*9(O:
2+9VDf2
startIndex); jR%*,IeB
} gG?@_ie
G80N8Lm
public PaginationSupport findPageByCriteria GRcPzneiz
>pF* unC;
(final DetachedCriteria detachedCriteria, finalint zj7ta[<tr
z:\9t[e4
pageSize, p@jw)xI
finalint startIndex){ i.mv`u Dm
return(PaginationSupport) M@ U>@x;
&J3QO%
getHibernateTemplate().execute(new HibernateCallback(){ 3RaduN]
publicObject doInHibernate AR[m+E
u`'"=Y_E
(Session session)throws HibernateException { E0ED[d,
Criteria criteria = $cSUB
}a;xs};X;
detachedCriteria.getExecutableCriteria(session); R1zt6oY
int totalCount = #Y=^4 U`
Mq\=pxC@
((Integer) criteria.setProjection(Projections.rowCount hhU_kI
D7hTn@I
()).uniqueResult()).intValue(); .~i|kc]Ue
criteria.setProjection Go%Z^pF3CO
VM$n|[C~
(null); G'JHimP2j
List items = {w2]
Is2F
HPphTu}`
criteria.setFirstResult(startIndex).setMaxResults |^Iox0A
O=jLZ2os
(pageSize).list(); zM0}(5$m
PaginationSupport ps = 2 5 \S>
.8YxEnXw)(
new PaginationSupport(items, totalCount, pageSize, RBQ8+^
+(*HDa|
startIndex); 8 W
return ps; gKh*q.
} .I^4Fc}&4
}, true); :-RB< Lj
} !+SL=xy!{
70qEqNoC
public List findAllByCriteria(final 72, m c
fOi
Rstci
DetachedCriteria detachedCriteria){ ]?}>D?5
return(List) getHibernateTemplate |.)LZP,
:qE.(k1@5
().execute(new HibernateCallback(){ z|>TkCW6
publicObject doInHibernate
y-hTTd"{
AqgY*"A7
(Session session)throws HibernateException { >/n];fl>8
Criteria criteria = 8"&!3_
d27q,2f!
detachedCriteria.getExecutableCriteria(session); b<tV>d"Fv
return criteria.list(); <D|&)/#
} mz0{eO
}, true); ~uhW~bT
} AMyg>n!
Y#os6|MV#
public int getCountByCriteria(final ~:Rbd9IB
0z/*JVka
DetachedCriteria detachedCriteria){ TnQ>v{Rx
Integer count = (Integer) P&Keslk
'iW
getHibernateTemplate().execute(new HibernateCallback(){ vbmt0df
publicObject doInHibernate &. =8Q?
>
'R{,1# U
(Session session)throws HibernateException { 5|rBb[
Criteria criteria = n.@HT"
|[rn/
detachedCriteria.getExecutableCriteria(session); _%CM<z
e
return HR-'8?)R.A
?;l@yx
criteria.setProjection(Projections.rowCount M8-8T
2G8w&dtu
()).uniqueResult(); Y#@D%
a 8
} ,NGHv?.N
}, true); #zP-,2!r
return count.intValue(); @V
' HX
} lc
<V_8
} :of([e|u6
@1oX
6_%Cd`4Z
cq[9#@
4=
no+m.B
|Z>-<]p9g
用户在web层构造查询条件detachedCriteria,和可选的 f9#zV2ke]
~lV#- m*
startIndex,调用业务bean的相应findByCriteria方法,返回一个 wXUR9H|0(
M+:5gMB'
PaginationSupport的实例ps。 ddgDq0N1j
0PkX- .
ps.getItems()得到已分页好的结果集 i`+w.zJOH8
ps.getIndexes()得到分页索引的数组 J?V$V
>d
ps.getTotalCount()得到总结果数 byI"
?
ps.getStartIndex()当前分页索引 ;87PP7~
ps.getNextIndex()下一页索引 6'r;6T *
ps.getPreviousIndex()上一页索引 SA'g`
ug,AvHEnB
f(y+1
}-tJ .3Zw
>12jU m)
WHx#;
uBts?02
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 bkdXBCBx?
N)mZ!K44
,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 ?pIELezfK
-Y524
一下代码重构了。 }aOqoi7w
.'=S1|_(
我把原本我的做法也提供出来供大家讨论吧: Sqi9'-%m
7@"X?uo%o
首先,为了实现分页查询,我封装了一个Page类: s={>{,E
java代码: KH,f'`
J299mgB
V%4P.y
/*Created on 2005-4-14*/ WdOxwsq"
package org.flyware.util.page; (RI)<zaK
;
%ap]\o$^4
/** [.>=>KJ_
* @author Joa 79 4UY
* .QP`Qn6 (P
*/ M.Q
HE2
publicclass Page { 4AL,=C3
PV\J]
|d,%
/** imply if the page has previous page */ uQ3sRJi
privateboolean hasPrePage; mo<*h&;&
2D%2k
/** imply if the page has next page */ _Yo)m|RaB
privateboolean hasNextPage; s=)W
qcO~}MJr}^
/** the number of every page */ ; s(bd#Q
privateint everyPage; WzFXF{(
A!GvfmzqIn
/** the total page number */ Aq(cgTNW
privateint totalPage; I'IFBVhaYn
2K_ QZ
/** the number of current page */ 6)sKg{H
privateint currentPage; m|fcWN[
AO`@&e]o
/** the begin index of the records by the current Yp(0 XP5o
<U$YJtEK
query */ `.;U)}Tn
privateint beginIndex; KK 7}q<&i
[GbrKq(
ZNH-0mk
/** The default constructor */ h<LS`$PK;E
public Page(){ \
C:Gx4K
I+Fy)=DO9
} T[OI/WuK
-Y+pLvG*
/** construct the page by everyPage *i*\dl
* @param everyPage ^nZ=B>Yn2
* */ r3x;lICx-
public Page(int everyPage){ ]+`K\G ^X
this.everyPage = everyPage; [>`.,k
} W'9{2h6u(
TAh'u|{u2
/** The whole constructor */ r]LP=K1
public Page(boolean hasPrePage, boolean hasNextPage, U{dK8~
?J6Ek*E#
#NyO'
int everyPage, int totalPage, )7Hx<?P
int currentPage, int beginIndex){ B tznms'
this.hasPrePage = hasPrePage; 5 `TMqrk
this.hasNextPage = hasNextPage; M>=@Z*u/+
this.everyPage = everyPage; ZzK^bNx)0
this.totalPage = totalPage; j8M t"B
this.currentPage = currentPage; `~\SQ EY$
this.beginIndex = beginIndex; ]4B;M Ym*
} hfJ&o7Dt
9q0s
/** ag8)^p'9
* @return b,:^\HKC
* Returns the beginIndex. i5(qJ/u
*/ n]vCvmt
publicint getBeginIndex(){ [3=Y 9P:
return beginIndex; %_n%-Qn
} ?`OFn F,K
(ID%U
/** h)sT37
* @param beginIndex 'r=2f6G>cP
* The beginIndex to set. e\ (X:T
*/ kt`ln
publicvoid setBeginIndex(int beginIndex){ tWl')^
this.beginIndex = beginIndex; \a0{9Xx F
} ir}*E=*
u0)O Fz
/** OE[7fDe'
* @return 5X3JQ"z
* Returns the currentPage. `dF~'
*/ 6|Dtx5
"r
publicint getCurrentPage(){ A]Hz?i
return currentPage; y)LX?d
} 3W ]zLUn
uN?Lz1W\;
/** @rqmDpU
* @param currentPage yU(}1ZID
* The currentPage to set. N
(\n$bpTt
*/ 5 jK|
publicvoid setCurrentPage(int currentPage){ C<C^7-5
this.currentPage = currentPage; QNE/SSL
} c{`!$Z'k<
((AK7hb
/** C &@'oLr
* @return 1LFad>`
* Returns the everyPage. 'H`:c+KDG`
*/ 3,Z;J5VL4!
publicint getEveryPage(){ )y:M8((%
return everyPage; x_8sV?F
} \aof
m{>"
/** x| D|d}
* @param everyPage
|,KsJ2hD
* The everyPage to set. ('%Y3z;
*/ [V
/f{y~{
publicvoid setEveryPage(int everyPage){ )6"p@1\u
this.everyPage = everyPage; KBi(Ns#+
} u*qI$?&
5mVO9Qj
/** YG?4DF
* @return dj5|t~&
* Returns the hasNextPage. L\#G#1x8
*/ {c
I~Nf?i
publicboolean getHasNextPage(){ %d-WQwJ
return hasNextPage; (-1{W^(
} NH5sV.vvc
w?3ww7yf`
/** _"H\,7E
* @param hasNextPage &RuTq6)r
* The hasNextPage to set. Y]~-S
*/
;j~%11
publicvoid setHasNextPage(boolean hasNextPage){ +p _?ekV\
this.hasNextPage = hasNextPage; Q6 o1^s
} 1foG*
< j
/** g<DXJ7o
* @return :Eh}]_
* Returns the hasPrePage. GXLh(d!C
*/ uZf
6W<a
publicboolean getHasPrePage(){ ~tL:r=
return hasPrePage; 2_bEo
} 67H?xsk@n
%Y/;jCY
/** $M,Q"QL
* @param hasPrePage IEM{?
* The hasPrePage to set. G{|"WaKW
*/ sm?b,T/
publicvoid setHasPrePage(boolean hasPrePage){ M4;M.zxJv
this.hasPrePage = hasPrePage; F;/^5T3wI
} c9@3=6S/
}"RVUYU
/** 4a!%eBhX"K
* @return Returns the totalPage. SH"<f_
* {&Rz>JK
*/ `X()"Qw
publicint getTotalPage(){ 5D-as9k*
return totalPage; *Vb#@O!
} eMEKR5*-O
1f"}]MbLR
/** Gys-Im6>~@
* @param totalPage xz}CqPJ#
* The totalPage to set. A#Ga!a
*/ 7On.y*
publicvoid setTotalPage(int totalPage){ lHliMBSc
this.totalPage = totalPage; Bn.R,B0PL
} HdY#cVxy
Y[VXx8"p
} AfZGI'%4[a
\Lb wfd=
%y_pF?2@q
W7.RA>
@qWClr{`
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 p.MLKp-'
KqBiF]Q
个PageUtil,负责对Page对象进行构造: -W/D Cj<
java代码: 2w~Vb0
8"LM:0x
qv2J0'd'.
/*Created on 2005-4-14*/ VWYNq^<AT
package org.flyware.util.page; e<8KZ
I@Yk &aU
import org.apache.commons.logging.Log; B"88 .U}$
import org.apache.commons.logging.LogFactory; V'za,.d-
xrlyph5mE
/** (Xzq(QV
* @author Joa EronNtu8i
* X=Y(,ZR(&
*/ o8A8fHl
publicclass PageUtil { wvxqgXnB\
KB~`3Wj|Z
privatestaticfinal Log logger = LogFactory.getLog =_6 Q26
yk^2<?z>2
(PageUtil.class); #K` [XA
JvCy&xrE;
/** cdI"=B+C\
* Use the origin page to create a new page c>r~pY~$
* @param page b;vVlIG
* @param totalRecords z0Y L,
* @return 9Ns%<FRO@
*/ ;_ 1Rk&o!
publicstatic Page createPage(Page page, int _S*QIbO
hr&UD| E=
totalRecords){ "cOBEhn%l
return createPage(page.getEveryPage(),
31]Vo;D
3UQBIrQ
page.getCurrentPage(), totalRecords); l Ny<E!0
} +,i_G?eX
I;<__
/** l4I',79l
* the basic page utils not including exception Y_XRf8Sw
az}zoFl
handler ?<OyJ|;V
* @param everyPage rc`I l{~k
* @param currentPage b
ts*qx&)
* @param totalRecords }\A0g}
* @return page uc=u4@.>
*/ pJo4&Ff
publicstatic Page createPage(int everyPage, int hO$29_^"
,d
HAD
currentPage, int totalRecords){ "HJQAy?W
everyPage = getEveryPage(everyPage); >Fe=PRs
currentPage = getCurrentPage(currentPage); @te}Asv
int beginIndex = getBeginIndex(everyPage, hbx+*KM
,oEAWNbgQ
currentPage); b$*G&d5
int totalPage = getTotalPage(everyPage, ep
l1xfr
O
"Aeg|
totalRecords); -O@/S9]S)
boolean hasNextPage = hasNextPage(currentPage, e)L!4Y44K
q #8z%/~k
totalPage); 27F:-C~.9
boolean hasPrePage = hasPrePage(currentPage); J3r':I}\
p@?(m/m$
returnnew Page(hasPrePage, hasNextPage, &Ci_wDJ
everyPage, totalPage, {-|El}.M
currentPage, sI4
FgO
)%:
W;H
beginIndex); kWbY&]ZO
} Sx_j`Cgy
n@oSLo`k,`
privatestaticint getEveryPage(int everyPage){ "/hLZl
return everyPage == 0 ? 10 : everyPage; MGo`j:0
} %7Gq#rq
+xr;X 9
privatestaticint getCurrentPage(int currentPage){ 1aUu:#c
return currentPage == 0 ? 1 : currentPage; K$$%j "s
} S;{[];
4LJOT_
privatestaticint getBeginIndex(int everyPage, int a=[|"J<M
1u*
(=!
currentPage){ EYZ,GT-I
return(currentPage - 1) * everyPage; \qJ^n %
} &';@CeK
OJ7y
privatestaticint getTotalPage(int everyPage, int ?xE'i[F @
AUaupNN
totalRecords){ $BOIa
int totalPage = 0; 25;`yB$
+J !1z
if(totalRecords % everyPage == 0) A<[w'"
totalPage = totalRecords / everyPage; MR* %lZpB
else oTpoh]|[
totalPage = totalRecords / everyPage + 1 ; !U1V('
n+'s9
return totalPage; t.7_7`bin~
} $bk_%R}s
%1i *Y*wg
privatestaticboolean hasPrePage(int currentPage){ .n}k,da@(
return currentPage == 1 ? false : true; "W"r0"4
} *MN("<A_
t\ 9Y)d
privatestaticboolean hasNextPage(int currentPage, ^;EwZwH[
O(T6Y80pU
int totalPage){ G?+]BIiL
return currentPage == totalPage || totalPage == ve*6WDK,H
)U2%kmt
0 ? false : true; Z1DF )
} &Qv%~dvW
u z:@
)Mw 3ZE92
} 7$:Jea
MV?sr[V-oP
T%2%*oa
VmTgD96
#XAH`L\
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。 /5:qS\Zl
@])}+4D(S
面对一个具体的业务逻辑:分页查询出User,每页10个结果。具体 35SL*zS@-
&$pA,Gjin\
做法如下: i]zTY\gw8M
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 Dr#V^"Dte
< 'r<MA<
的信息,和一个结果集List: h)?Km{u%
java代码: ">R`S<W
^aL> /'Y#|
95-%>?4
/*Created on 2005-6-13*/ bj+foNvu\
package com.adt.bo; Ozc9y y!%
ze#ncnMo
import java.util.List; K`cy97
h56s ~(?O
import org.flyware.util.page.Page; |Lz7}g=6
.@f)#2
/** "(E%JAwZ^W
* @author Joa i
th!,jY*i
*/ IpsV4nmnz-
publicclass Result { d|$-Sz
\
id(P3M
private Page page; FVoKNaK-
+hMF\@
private List content; NJ!}(=1|K
9CHn6 v ~)
/** P6 mDwR
* The default constructor
W o$UV
*/ !%G;t$U=M
public Result(){ ev(E
super(); ~ZRtNL9
} T;B/Wm!x
:J6FI6
/** }+
TA+;
* The constructor using fields sQa9M
* )Z@hk]@?_[
* @param page Th 5}?j7
* @param content ;UWp0d%
*/ x/#.%Ga#T
public Result(Page page, List content){ @S Quc
this.page = page; Y/34~lhyl
this.content = content; 6NzS <
} #4?:4Im#
U{-[lpd
/** X\]Dx./
* @return Returns the content. qk\LfRbj
*/ ig:z[k?
publicList getContent(){ v|YJ2q?19
return content; 7o`pNcabtz
} PAy7b7m~B
(:J
U
/** G)y'ex k
* @return Returns the page. 4 !M6RL8{
*/ 0,[-4m
public Page getPage(){ ${, !L l7)
return page; Fk&A2C}$b
} hUMFfc?
[$%0[;jtS
/** Y]HtO^T2
* @param content 0:k
MnHn\
* The content to set. 0XrOOYmx
*/ ))#_@CwRr
public void setContent(List content){ *XqS~G
this.content = content; %Wb$qpa
} K/XUF#^B]
3x~AaC.j
/** 15`,kJSK
* @param page B7BikxUa
* The page to set. O6r.q&U
*/ ? 1b*9G%i
publicvoid setPage(Page page){ C)qP9uW
this.page = page; ,DWC=:@X
} 9 kS;_(DB
} <<9Y=%C+
{c:ef@'U
OL$^7FB
fsVr<m
=J&aN1Hgt
2. 编写业务逻辑接口,并实现它(UserManager, bR?
$a+a)
Jl^THoEL
UserManagerImpl) JB\BP$ap
java代码: {_*$X
>{kPa|
~qmu?5
/*Created on 2005-7-15*/
`_H^k!^
package com.adt.service; _<G%
Y@M
l}43
import net.sf.hibernate.HibernateException; rlVo}kc7:
} T<oLvS
import org.flyware.util.page.Page; 4xNzhnp|
O\qY?)
import com.adt.bo.Result; <\5Y~!)
nXF|AeAco
/** z6Jfu:_N!
* @author Joa f@= lK?Pfh
*/ .TWX,#
publicinterface UserManager { mdD9Q
N01
)VCRbz"[g
public Result listUser(Page page)throws H(Q|qckj
;
+E@h=?
HibernateException; U?Icyn3q0
HFd>UdT%
} 4 jeUYkJUM
Pxm~2PAm
o+Kh2;$)
Lg4I6 G
BHBMMjY5
java代码: l<mEGKB#
k@= LR
P(BV J_n
/*Created on 2005-7-15*/ :,(ZMx\
package com.adt.service.impl; d[.JEgU
(KxL*gB
import java.util.List; j;b<oQH
1z[GY RSt
import net.sf.hibernate.HibernateException; H/ 6GD,0
pu*vFwZ
import org.flyware.util.page.Page; Y4|g^>{<ni
import org.flyware.util.page.PageUtil; uua1_#a
*!y.!v*
import com.adt.bo.Result; iy_\1jB0
import com.adt.dao.UserDAO; \3@A C7
import com.adt.exception.ObjectNotFoundException; |+MV%QG;
import com.adt.service.UserManager; P>t[35/1
U)N_/
/** |E)IJj
3
* @author Joa 2<@27C5
*/ r?= 7#/]
publicclass UserManagerImpl implements UserManager { ly]n2RK
1$Pn;jg:
private UserDAO userDAO;
h8!;RN[
KGm"-W
/** Rl""
aZ
* @param userDAO The userDAO to set. yxa~Rz/
*/ qm)KO 4
publicvoid setUserDAO(UserDAO userDAO){ 5CsJghTw
this.userDAO = userDAO; .1F^=C.w
} H19CVc\B
k98}Jx7J)"
/* (non-Javadoc) k(;c<Z{?1
* @see com.adt.service.UserManager#listUser ^f,('0p->
XHlx89v7
(org.flyware.util.page.Page) *?+maK{5+
*/ Y(]&j`%
public Result listUser(Page page)throws \ns#l@B
#?z1cgCg
HibernateException, ObjectNotFoundException { ?DC3BA\)
int totalRecords = userDAO.getUserCount(); N|ut^X+|\
if(totalRecords == 0) $v6dB {%Qu
throw new ObjectNotFoundException i%~4 >k
Vhww-A
("userNotExist"); O$%C(n(
page = PageUtil.createPage(page, totalRecords); x6ig,N~AO
List users = userDAO.getUserByPage(page); &:` 7
returnnew Result(page, users); 4{\h53j$
} z.[ Ok
m
dC.M$
} {Z_Pry$6
I/s?]v
gi7As$+E
n8M/Y}mH
M,Px.@tw.
其中,UserManagerImpl中调用userDAO的方法实现对User的分页查 X~Li`
1lNg} !)[K
询,接下来编写UserDAO的代码: 9 0[gXj
3. UserDAO 和 UserDAOImpl: 4>gMe3]0
java代码: e.0vh?{\
9zkR)C
eD, 7gC-
/*Created on 2005-7-15*/ yoj5XBM
package com.adt.dao; LTY@}o]\U
1px:(8]{
import java.util.List; |400N
+MK
d+|8({X]D8
import org.flyware.util.page.Page; gtHk1 9
>=2nAv/(
import net.sf.hibernate.HibernateException; P$)9osr
x
c-=;|s
/** L$`!~z1
* @author Joa A]{8=
*/ &Sc}3UI/F
publicinterface UserDAO extends BaseDAO { g2hxWf"
3Lq?Y7#KQp
publicList getUserByName(String name)throws =ot`V; Q>
HPT9B?^
HibernateException; }b
YiyG\
,7pO-:*g
publicint getUserCount()throws HibernateException; 1GW=QbO 6
}@OykN
publicList getUserByPage(Page page)throws 0X)'8N
%+G/oF|
HibernateException; SF;;4og
8jjJ/Mz`
} 'W$jHs
f$k#\=2%
)4a&OlEI
];1z%.
<9/oqp{C4
java代码: 2&]UFg:8Q
EG0NikT?
/
GJ"##<
/*Created on 2005-7-15*/ awXL}m[_!
package com.adt.dao.impl; =5LtEgHU
;P _`4w3
import java.util.List; $<]y.nr|CX
lE[LdmwDrb
import org.flyware.util.page.Page; A"C%.InZ
:f^O!^N
import net.sf.hibernate.HibernateException; 1`m ~c
import net.sf.hibernate.Query; ^$_a_ft#
e9q/[xMi
import com.adt.dao.UserDAO; FQ?H%UcW
xN}P0
/** g=[ F W@z
* @author Joa qrNW\ME
*/ (^9q7)n
public class UserDAOImpl extends BaseDAOHibernateImpl tGd9Cs9D<
7s5?^^
implements UserDAO { "F|OJ@M
-NZj : N
/* (non-Javadoc) :M ix*NCf
* @see com.adt.dao.UserDAO#getUserByName r[M]2h
ZH`6>:
(java.lang.String) TRAs5I%
*/ q?Q"Ab
publicList getUserByName(String name)throws n\*>mp)
*`);_EVc
HibernateException { t3Q;1#Zf
String querySentence = "FROM user in class 9))%tYN
!hFb<
com.adt.po.User WHERE user.name=:name"; rP;Fh|w#
Query query = getSession().createQuery 3T Q#3h
,vW.vq<{q3
(querySentence); *D,+v!wG9
query.setParameter("name", name); '4FS.0*_
return query.list(); PQvq$|q
} Roy`HU
;0a
S5v>WI^0h
/* (non-Javadoc) ui7 0|
* @see com.adt.dao.UserDAO#getUserCount() nUhD41GJ
*/ ?GD{}f33
publicint getUserCount()throws HibernateException { ED"5y
int count = 0; Y#{KGVT<
String querySentence = "SELECT count(*) FROM ',6QL4qV/
.K}u`v T
user in class com.adt.po.User"; R.|fc5_"+
Query query = getSession().createQuery $|6Le;
K
cdP+X'Y4D
(querySentence); ))G%C6-
count = ((Integer)query.iterate().next Y: KB"H
\E?1bc{\f
()).intValue(); O`t ]#
return count; *
2T&