Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 Ob&W_D^=N
$@87?Ab
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 UxPGv;F
-ID!pT vW
据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 B3L4F"
}]h\/,
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 jEU'.RBN%
\5[-Ml
。 Kd{#r/HZ
g{DFS[h
分页支持类: ujx-jIhT_
lIDl1Z@Z
java代码: ^LO]Z
3YTIH2z5
5
;vC(Go
package com.javaeye.common.util; 8gpB z'/,
2lz
{_9
import java.util.List; G\/IM
Hhf72IX
publicclass PaginationSupport { Wu{&;$
iK x+6v
publicfinalstaticint PAGESIZE = 30; DPPS?~Pq
dM|g`rr
E
privateint pageSize = PAGESIZE; ^]rxhpS
u_'nOle
K
privateList items; ;nf&c;D
Iu6W=A
privateint totalCount; +L6" vkz
rdI]\UH
privateint[] indexes = newint[0]; -lp"#^ ;
:J%'=_I&H
privateint startIndex = 0; rsSue_Q
p+D=}O
public PaginationSupport(List items, int g3a/;wl
.;%q/hP
totalCount){ [#X|+M&u6
setPageSize(PAGESIZE); k|ip?O
setTotalCount(totalCount); BHiOQ0Fs
setItems(items); h3t$>vs2F"
setStartIndex(0); j#o3
} [`bZ5*&
*SGlqR['\e
public PaginationSupport(List items, int D{svR-~T
z_)`g`($
totalCount, int startIndex){ Sf5]=F-w
setPageSize(PAGESIZE); Hd*Fc=>"Y
setTotalCount(totalCount); QE6El'S
setItems(items); |B|@GF?:
setStartIndex(startIndex); yam}x*O\xn
} 3B"7VBK{
AgI >
public PaginationSupport(List items, int qhwoV4@f
V#H8d_V
totalCount, int pageSize, int startIndex){ f#mx:Q.7I
setPageSize(pageSize); g$gS7!u,
setTotalCount(totalCount); ^teaJ y%
setItems(items); gD5P!}s[u0
setStartIndex(startIndex); 9i[4"&K
} fn?VNZ`J
??+:vai2
publicList getItems(){
X4
Y
return items; u
!.DnKu
} ULTNhq
R*n
#'g^Za
publicvoid setItems(List items){ e7's)C>/'
this.items = items; eRVY.E<
} |=,83,a
y;,y"W
publicint getPageSize(){ OgTSx
return pageSize; z1}1*F"
} B{=009.
<hMtE/05B
publicvoid setPageSize(int pageSize){ Z{#"-UG
this.pageSize = pageSize; sr4jQo
} qhN[Dj(d
q'2`0MRa
publicint getTotalCount(){ @5GBuu^j
return totalCount; 2b!j.T#u
} *k!(ti[
Np)ho8zU
publicvoid setTotalCount(int totalCount){ RCCv>o
if(totalCount > 0){ F1\`l{B,\
this.totalCount = totalCount; &!OGIYC(
int count = totalCount / qlEFJ5;
fo;6huz
pageSize; m6eFXP1U
if(totalCount % pageSize > 0) Vbo5`+NAis
count++; ])S$x{.g
indexes = newint[count]; [tOuNj:
for(int i = 0; i < count; i++){ jF4csO=E
indexes = pageSize * (>mi!:
UIz:=DJ
i; '6+Edu~Ho)
} j;G[%gi6{
}else{ ,FY-d$3)
this.totalCount = 0; Y[h#hZ
} Wge ho
} hRRkFz/0&
u8^Y,LN
publicint[] getIndexes(){ W?=$V>)
return indexes; 7|K3WuLL
} 7}A5u,.,ht
Nr%(2[$ =
publicvoid setIndexes(int[] indexes){ 0 K/G&c?;=
this.indexes = indexes; RP(a,D|
} KS?mw`Nr
B%2L1T=
publicint getStartIndex(){ <_>.!9q
return startIndex; T
G_bje
} CJv>/#$/F
.hc|t-7f
publicvoid setStartIndex(int startIndex){ ?Q;kZmQl
if(totalCount <= 0) 5cgo)/3M@}
this.startIndex = 0; \WiqN*ZF
elseif(startIndex >= totalCount) ' *}^@[&
this.startIndex = indexes M5F(<,n;
gA{'Q\
[indexes.length - 1]; }'DC
Q
elseif(startIndex < 0) C`3V=BB
this.startIndex = 0; LSSW.Oz2L
else{ %V31B\]Nz7
this.startIndex = indexes L
43`^;u
Ut]2` 8-
[startIndex / pageSize]; 6zv;lx0<D&
} eN2dy-0
} G l_\Vy
oPCrD.s
publicint getNextIndex(){ F OeVRq:#
int nextIndex = getStartIndex() + "Wo.8
"/Om}*VhD
pageSize; {K<uM'ww>
if(nextIndex >= totalCount) {>wI8
return getStartIndex(); m"<4\;GK
else I/Sv"X6E
return nextIndex; KUF$h Er
} xrfPZBLy
h4tC. i~k
publicint getPreviousIndex(){ r|*:9|y{"/
int previousIndex = getStartIndex() - sfyBw
7AI3|Ts]p
pageSize; NvUu.
if(previousIndex < 0) ud yAP>
return0; ]{(l;k9=e
else m dC`W&r
return previousIndex; 09G9nu ;&{
} XO 0>t{G
z<n"{%
} V_Xy2<V
oDz*~{BHg
=x=1uXQv5
nrF%wH/5
抽象业务类 T_uNF8Bh
java代码: O;UiYrXU
8n;kK?
@55bE\E?@
/** ^I@ey*$
* Created on 2005-7-12 `E{;85bDH
*/ anK[P'Y
package com.javaeye.common.business; ~l(G6/R
_t$lcOT
import java.io.Serializable; C5>{Q:.`e'
import java.util.List; XI]OA7Zis
I0I_vu
import org.hibernate.Criteria; ^OsA+Ea\
import org.hibernate.HibernateException; F='Xj@&O
import org.hibernate.Session;
;&K3[;a
import org.hibernate.criterion.DetachedCriteria; 4Y`! bT`
import org.hibernate.criterion.Projections; EfFj!)fz
import v$[ @]`
A(q~{
org.springframework.orm.hibernate3.HibernateCallback; |VTWw<{LX
import V/`#B$6
l{nB.m2
org.springframework.orm.hibernate3.support.HibernateDaoS `x2fp6
qnabw F
upport; J'|=*#
DhY;pG,t
import com.javaeye.common.util.PaginationSupport; d|>9rX+f
RcY6V_Qx
public abstract class AbstractManager extends se~ *<5
:|?~B%-p[
HibernateDaoSupport { W3Fy mCI
qRgK_/[]
privateboolean cacheQueries = false;
NdM}xh
p^p'/$<6_
privateString queryCacheRegion; GA'*58
M7`UoTc+>d
publicvoid setCacheQueries(boolean 1f+*Tmc5]Q
DfAiL(
cacheQueries){ oN.Mra]D
this.cacheQueries = cacheQueries; Bx\#`Y
} }W - K
d8xk&za
publicvoid setQueryCacheRegion(String :jZ*,d%1={
7'-)/Pk
queryCacheRegion){ Iu)L3_+
this.queryCacheRegion = _pY
c80
}1
queryCacheRegion; M/n[&
} ~z\pI|DQ
B=Xnv*e
publicvoid save(finalObject entity){ |M[v493\
getHibernateTemplate().save(entity); j)6@q@P/
} /uy&2l
@#bBs9@gv
publicvoid persist(finalObject entity){ 9`ri
J4zl
getHibernateTemplate().save(entity); wk-Mu\
} N2[, aU
L~^e\^sP
publicvoid update(finalObject entity){ 1.hOE>A%
getHibernateTemplate().update(entity); +9<,3IJe6
} 0-8ELX[#
~*66 3pA
publicvoid delete(finalObject entity){ |usnY
getHibernateTemplate().delete(entity); XS}Zq4H
} (Q}PeKM?jq
H=JP3ID>{
publicObject load(finalClass entity, ^ %~Et>C
3&.TU5]`-
finalSerializable id){ FiV^n6-F`
return getHibernateTemplate().load >GdLEE'w
\_iH4<#>
(entity, id); 7VEt4
} Ig40#pA
E'S<L|A/
publicObject get(finalClass entity, [+%p!T
@oe3i
finalSerializable id){ Hl%+F0^?
return getHibernateTemplate().get -L^0-g
Mft0Dj/
(entity, id); w3>Y7vxiz`
} ,gFL Wb`B'
HB/
_O22
publicList findAll(finalClass entity){ o=a:L^nt,
return getHibernateTemplate().find("from 7?kXgR[#d
~NNaLl
" + entity.getName()); ZaEBdBv
} 9m<X-B&P
kMwIuy
publicList findByNamedQuery(finalString S>/I?(J
+1JZB*W
namedQuery){ =$:4v`W0(
return getHibernateTemplate Y\\3g_YBF
b&U5VA0=1
().findByNamedQuery(namedQuery); dK=D=5r,
} 0C9QAJa
x| ~D(zo
publicList findByNamedQuery(finalString query, N7j]yvE
a$+e8>
finalObject parameter){ a9mr-`<
return getHibernateTemplate T }8r;<P6
p ] $
().findByNamedQuery(query, parameter); W#JVU GYD
} '|dKg"Yl
&9jUf:g J0
publicList findByNamedQuery(finalString query, 37ri b
8V53+]c$Y
finalObject[] parameters){ skmDsZzw
return getHibernateTemplate P /f ~
h!JjN$
().findByNamedQuery(query, parameters); E|8s2t
} I'6ed`|
#nMP(ShK
publicList find(finalString query){ hg86#jq%
return getHibernateTemplate().find |Ls&~'ik
8WLh]MD`
(query); RY'\mt"W2
} ^q4:zZZ
j*3sjOoC
publicList find(finalString query, finalObject ( .6tz
R- ?0k:
parameter){ %_i0go,^
return getHibernateTemplate().find OFPd6,(E
x.yb4i=Jq
(query, parameter); Z"+rg9/p
} .DV#-tUh
6|(7G64{
public PaginationSupport findPageByCriteria _UbR8
onS{
(final DetachedCriteria detachedCriteria){ `5~o=g
return findPageByCriteria JzS^9)&
EC\rh](d
1
(detachedCriteria, PaginationSupport.PAGESIZE, 0); 9g^./k\8%
} N#xM_Mpt
w4&v( m
public PaginationSupport findPageByCriteria .Q6{$Y%l
'!|E+P-
(final DetachedCriteria detachedCriteria, finalint ht[TMdV
,_X,V!
startIndex){ !gA^$(=:"
return findPageByCriteria t g m{gR
jAQ)3ON<
(detachedCriteria, PaginationSupport.PAGESIZE, ^PCL^]W
-7Y'6''~W.
startIndex); 9M-]~.O
} A$Jn3Xd~!
J4R
public PaginationSupport findPageByCriteria d+$[EDix
=4%WOI
(final DetachedCriteria detachedCriteria, finalint Wf&G9Be?8
fb S.
pageSize, (}7o
a9Q<
finalint startIndex){ \FaB!7*~
return(PaginationSupport) 4j=@}!TBt
B#/~U`t*
getHibernateTemplate().execute(new HibernateCallback(){ &hM,b!R|
publicObject doInHibernate xBx?>nN
f"}14V
(Session session)throws HibernateException { <3]/ms
Criteria criteria = b ffml
>Gu>T\jpe.
detachedCriteria.getExecutableCriteria(session); A<G ;
int totalCount = ?2bE=|
]MH
\3g;
((Integer) criteria.setProjection(Projections.rowCount 3T#3<gqM[
o@V/37!
()).uniqueResult()).intValue(); B2+_F"<;
criteria.setProjection q~A|R
:WKyEt!3
(null); ,C12SM*@
List items = (V|q\XS
w `9GygS
criteria.setFirstResult(startIndex).setMaxResults t6U+a\-<
0O9
Lg}
(pageSize).list(); :ftyNaq'
PaginationSupport ps = L[9+xK^g
Z~R/p;@
new PaginationSupport(items, totalCount, pageSize, ki/Lf4
(fjXp75
startIndex); :\HN?_?{4
return ps; 9%hB
} -T="Ml&
}, true); *{n,4d\..
} fJN9+l
(h(ZL9!
public List findAllByCriteria(final q|Tk+JH{5
%Zi,nHg8
DetachedCriteria detachedCriteria){ |D_n4#X7u
return(List) getHibernateTemplate SEn8t"n
<PA$hTYM
().execute(new HibernateCallback(){
T?$?5
publicObject doInHibernate 0|3B8m
}lbx
(Session session)throws HibernateException { &[\arwe)
Criteria criteria = dodz|5o%
Fu=VY{U4
detachedCriteria.getExecutableCriteria(session); i3\oy`GJ
return criteria.list(); E52:c]<'m
} ZCq\Zk1O&
}, true); mgl'
d
} 5Szo5
HrcnyQ`Q0
public int getCountByCriteria(final 'aSORVq^e[
oFA$X Y
DetachedCriteria detachedCriteria){ =:T:9Y_ i
Integer count = (Integer) ,PtR^" Mf4
GTX&:5H\t
getHibernateTemplate().execute(new HibernateCallback(){ (IWd?,H,n
publicObject doInHibernate y"n~ET}e7
$7ME a"a
(Session session)throws HibernateException { h-u*~5dB<&
Criteria criteria = =>TtX@ Q{
$TUC?e9"h
detachedCriteria.getExecutableCriteria(session); w@D@,q'x
return >}`1'su
iDe0 5f1R
criteria.setProjection(Projections.rowCount -cS4B//IK8
2yg'?tpj
()).uniqueResult(); Wa<NId
} t"m`P1
}, true); Z-=7QK.\{
return count.intValue(); &]A1 _dy
} %x)U8
} P>cJ~FM
Lgw@y!Llij
o`]FH_
+Gs;3jC^
m^&mCo,
*^m.V=
用户在web层构造查询条件detachedCriteria,和可选的 ?9M+fi
B,qZwc|
startIndex,调用业务bean的相应findByCriteria方法,返回一个 yD'h5)yu
&~6O;}\
PaginationSupport的实例ps。 E&=?\KM
y")>"8H
ps.getItems()得到已分页好的结果集 iONql7S @
ps.getIndexes()得到分页索引的数组 y3$\ m
ps.getTotalCount()得到总结果数 ZI*A0_;L
ps.getStartIndex()当前分页索引 `9)2nkJk'z
ps.getNextIndex()下一页索引 lP
&%5y;
ps.getPreviousIndex()上一页索引 Hw3E S
, 0ja _
d:ajD
uy28=BE
8i~'~/x
.}op mI
0L-g'^nn
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 k3eN;3#&
zm.sX~j
,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 / S^m!{
J*k=|+[
一下代码重构了。 >I;#BE3
B_1u<00kg
我把原本我的做法也提供出来供大家讨论吧: ^OsUWhkV
BuO J0$
首先,为了实现分页查询,我封装了一个Page类: ^ @cX0_
java代码: 9%veUvY
%zVv3p:
D($UbT-v
/*Created on 2005-4-14*/ *m/u 3.\
package org.flyware.util.page; PhdL@Mr
BAed [
/** `{[C4]Ew/
* @author Joa ^W*)3;5
* 5.;$9~d
*/ ]zAg6*-/B
publicclass Page { JG$J,!.\
vIv3rN=5vB
/** imply if the page has previous page */ rI$10R$+H
privateboolean hasPrePage; JH,+F
T0C'$1T
/** imply if the page has next page */ ,o6: V]a
privateboolean hasNextPage; 7hE=+V8
Jk{2!uP
/** the number of every page */ 5Uz(Bi
privateint everyPage; wYM{x!D
J~6*d,Ry`
/** the total page number */ :36^^Wm
privateint totalPage; <o`]wOrl
N_}Im>;!
/** the number of current page */ !I$RE?7eY
privateint currentPage; ~|]\.^B
wN.Jyb
/** the begin index of the records by the current Ee| y[y,
1z!Lk*C)
query */ 8`<GplO
privateint beginIndex; :RG6gvz
$9$NX/P
$l0w {m!P
/** The default constructor */
fQ) ;+
public Page(){ wEqCuhZ
6f1Y:qK'@
} *GnO&&m'B
>@W#@W*I@
/** construct the page by everyPage KLB?GN?Pb
* @param everyPage ax }Xsk_
* */ ]P5u:~U
public Page(int everyPage){ e70*y'1fu
this.everyPage = everyPage; %oQj^r!Xd
} KO7cZME
H2-(
/** The whole constructor */ P]^]
T}5
public Page(boolean hasPrePage, boolean hasNextPage, J]e&z5c
2j|Eh
".=EAXVU
int everyPage, int totalPage, )Qp?LECrt
int currentPage, int beginIndex){ "[,XS`
this.hasPrePage = hasPrePage; rZ7 Ihof
this.hasNextPage = hasNextPage; %&NK|M+n
this.everyPage = everyPage; ^hJ,1{o
this.totalPage = totalPage; efm<bJB2
this.currentPage = currentPage; 0cVXUTJ|W
this.beginIndex = beginIndex; J(GLPC O$K
} l1-FL-1
MR: {Ps&,
/**
C5?M/xj
* @return Nq3P?I(<
* Returns the beginIndex. m5*RB1
*/ ^%.<(:k[L
publicint getBeginIndex(){ \Ld7fP
return beginIndex; chbs9y0
} X+jSB,
Vy VC#AK,
/** =<icHt6s
* @param beginIndex N\$6R-L
* The beginIndex to set. nXjUTSGa)
*/ `MS=/x E
publicvoid setBeginIndex(int beginIndex){ HF:PF"|3
this.beginIndex = beginIndex; $fO*229As
} J.(_c'
r
,GlK_-6>
/** f
#14%?/
* @return 7y3; F7V
* Returns the currentPage. *!kg@ _0K
*/ sa($3`d
publicint getCurrentPage(){ hJM0A3(Cm
return currentPage; N4pA3~P
} a;sZNUSn
?u|g2!{_
/** H'.d'OE:I
* @param currentPage -mF9Skj
* The currentPage to set. J\BdC];
*/ -1:asM7
publicvoid setCurrentPage(int currentPage){ U ;/ )V
this.currentPage = currentPage; @AFLF X]
} J^T66}r[f,
ub&1L_K
/** L
$~Id
* @return lHU$A;
* Returns the everyPage. YDwns
*/ qJsEKuOs
publicint getEveryPage(){ ,??|R`S
return everyPage; p%_TbH3j`
} AKVmUS;70
SF7Kb `>Y
/** 622).N4
* @param everyPage pWqahrWh
* The everyPage to set. SzDi=lY
*/ *SZ<ori
publicvoid setEveryPage(int everyPage){ J.*=7zmw
this.everyPage = everyPage; w~`P\i@
} 3ba"[C|
l`k3!EZDS
/** D{mu2'q
* @return +q;^8d>
* Returns the hasNextPage. r BL)ct
*/ _cB~?c
publicboolean getHasNextPage(){ /[p4. FL
return hasNextPage; ?w+T_EH
} Hs9uDGWp
R B!g,u
/** Gu-Sv!4p
* @param hasNextPage *,(`%b[
* The hasNextPage to set. NNT9\JRv_
*/ C^a~)r.h
publicvoid setHasNextPage(boolean hasNextPage){ |[ge,MO:
this.hasNextPage = hasNextPage; $FoNEr&q
} 8`D_"3j3g\
4d#W[
/** 9M6&+1XE
* @return .IqS}Rh
* Returns the hasPrePage. `fH6E8N
*/ u=4Rn
publicboolean getHasPrePage(){ 1DX=\BWp
return hasPrePage; IpWl;i`__
} q&vr;fB2
5Z@Q^
/** <(v!Xj^yO
* @param hasPrePage }\@*A1*X2
* The hasPrePage to set. ,T]okN5uI
*/ Dbgw)n*2
publicvoid setHasPrePage(boolean hasPrePage){ 7-^d4P+|g
this.hasPrePage = hasPrePage; :KQ<rLd
} N;htKcZ
@'S-nn,sO
/** Mqq7;w@(J
* @return Returns the totalPage. lHx$F?
* {AZW."?
*/ G B15
publicint getTotalPage(){ 4 1Ru@
return totalPage; d+_qBp
} TY?Fs-
P63f0F-G
/** BUtXHD
* @param totalPage 9N9;EY-U
* The totalPage to set. (*|hlD~
*/ Q@2Smtu~c
publicvoid setTotalPage(int totalPage){ ~($h9*\
this.totalPage = totalPage; [g<JP~4]
} SW bwD/SN
HH>]"mv
} -gzk,ymp
mX
%;
_Ab|<!a/R
C,Ch6Ph
A;h~Fx6s
上面的这个Page类对象只是一个完整的Page描述,接下来我写了一 :}Z+K*%o-
,9=a(j"
个PageUtil,负责对Page对象进行构造: !fZxK CsQ
java代码: v,kedKcxv'
~}uTC36C\
}v`5
/*Created on 2005-4-14*/ BwbvZfV|
package org.flyware.util.page; n]|[|Rf1
ZMbv1*Vt
import org.apache.commons.logging.Log; 9= :!XkT.
import org.apache.commons.logging.LogFactory; v-OaH81&R
`a]
/e
/** Zd042
%
* @author Joa #*5A]"k
* @dGj4h.
*/ =*}|y;I
publicclass PageUtil { NKO5c?ds
gVA$P
privatestaticfinal Log logger = LogFactory.getLog !tN]OQ)'
]@Q14
(PageUtil.class); w_6h
$"^x
jytfGE:
/** xCGvLvFn
* Use the origin page to create a new page EFhe``
* @param page UDhW Y.`'~
* @param totalRecords aabnlOVw
* @return BJ1txdxvS
*/ K@ 6$|.bc
publicstatic Page createPage(Page page, int >{V]q*[/;Q
FSC74N/
totalRecords){ YaDr6)
return createPage(page.getEveryPage(), X]M)T
B]#0]-ua
page.getCurrentPage(), totalRecords); .(`#q@73
} 1Sr@$+VGO
%
?@PlQ
/** )FYz*:f>&
* the basic page utils not including exception u+kXJ
wYPJji
D
handler Syo1Dq6z.
* @param everyPage uveTx
* @param currentPage *q\Ve)E}
* @param totalRecords fMy7pXa_
* @return page Quqts(Q) +
*/ k& 2U&
publicstatic Page createPage(int everyPage, int MZv In ZS
XnV*MWv
currentPage, int totalRecords){ ez@`&cJ7
everyPage = getEveryPage(everyPage); nZ0-
Kb
currentPage = getCurrentPage(currentPage); =]K;"
int beginIndex = getBeginIndex(everyPage, oqc89DEbJ
D37N*9}
currentPage); bx#GOK-
int totalPage = getTotalPage(everyPage, IVjH.BzH9
!?,7Cu.5#6
totalRecords); Tu"bbc
boolean hasNextPage = hasNextPage(currentPage, bH% k)
b3N1SC:Wn
totalPage); SxI='z_S.f
boolean hasPrePage = hasPrePage(currentPage); -W38#_y/\
omevF>b;
returnnew Page(hasPrePage, hasNextPage, MqDz cB]
everyPage, totalPage, '_N~PoV
currentPage, .B_LQ;0:
jdqVS @SD
beginIndex); 6vAq&Y{JB'
} *](maF~%C
'[Ap/:/UY
privatestaticint getEveryPage(int everyPage){ .7 6T<j_
return everyPage == 0 ? 10 : everyPage; QpxRYv
} % put=I
>slD.rb]
privatestaticint getCurrentPage(int currentPage){ hd0d
gc
return currentPage == 0 ? 1 : currentPage; 4jbqV
} <=[,_P6|
,@!io
privatestaticint getBeginIndex(int everyPage, int {]BPSj{B
ek\8u`GC
currentPage){ +i HZ*
return(currentPage - 1) * everyPage; z~f Zg6
} TwJiYXHw?
-FftEeo7
privatestaticint getTotalPage(int everyPage, int Jh`Pq,B:
,j E'd'$
totalRecords){ Fjch<gAofS
int totalPage = 0; &\),V 1"
BPs|qb-
if(totalRecords % everyPage == 0) jGy%O3/
totalPage = totalRecords / everyPage; Hz~?"ts@;
else Yz7H@Y2i
totalPage = totalRecords / everyPage + 1 ; .,[NJ:l
+}1h
return totalPage; &\6Buw_
} gCfAy=-,V
p)2
!_0
privatestaticboolean hasPrePage(int currentPage){ }% 2hBl/
return currentPage == 1 ? false : true; WRrCrXP
} s2F<H#
paCC'*bv
privatestaticboolean hasNextPage(int currentPage, :x88
$]LhE:!G
int totalPage){ OD{()E?1B
return currentPage == totalPage || totalPage == ~C M%WvS
w(Jf;[o
0 ? false : true; pV:;!+
}
h.T]J9;9
q9+`pj
X%JQ_Z
} 3<F\5|
.Z?@;2<l
T<XGG_NOl
8k[=$Ro
p6S{OUiG
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%pJdPk=
W3Gg<!*Uo
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 :DWvH,{+&
|z.x M>
做法如下: b-!+Q)
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 _UP=zW
c+S<U*
的信息,和一个结果集List: vX?MB
java代码: Lsu_f'p0
>%6a$r~@
]cQYSN7!SY
/*Created on 2005-6-13*/ ({&