Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ~ 5"JzT
5 `/< v^
detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 jNDx,7F-
muON>^MbC
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 <@v]H@E
R9+jW'[K
自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 V9NTs8LKc
k?GD/$1t
。 *Mc7f ?H
w8Sv*K
分页支持类: c]k*}W3T
_QOZsEe
java代码: $.%rAa_H
AnBJ(h
G\d$x4CVGc
package com.javaeye.common.util; 8jlLUG:g
yY).mxRN
import java.util.List; ;E^K.6
/b#l^x:j
publicclass PaginationSupport { Ta=s:trP
>o,^b\
publicfinalstaticint PAGESIZE = 30; /# NYi,<{X
Q
n)d2-<
privateint pageSize = PAGESIZE; $tqJ/:I
R\3VB NX.g
privateList items; K$ }a8rH
5Qwh(C^H
privateint totalCount; AM"jX"F9/
Io`P,l:
privateint[] indexes = newint[0]; qy1F*kY
hB;VCg8
privateint startIndex = 0; |KI UgI
Lo.rvt
public PaginationSupport(List items, int am1[9g8L
x\e;+ubt}
totalCount){ 0fXLcal
setPageSize(PAGESIZE); ,8'>R@o
setTotalCount(totalCount); n{0Ld -zH
setItems(items); qFX~[h8i+
setStartIndex(0); U @v*0
} !|waK~jK
?4H#G)F
public PaginationSupport(List items, int Z6C=T;w
VXBY8;+Yp
totalCount, int startIndex){ pO Iq%0]
setPageSize(PAGESIZE); eDI=nSo
setTotalCount(totalCount); 8LkP)]4^sO
setItems(items); IA zZ1#/3
setStartIndex(startIndex); W<ZK,kv
} 6DIZ@ oi
g6t"mkMY
L
public PaginationSupport(List items, int /hrT
O43YY2
totalCount, int pageSize, int startIndex){ $q?$]k|M`
setPageSize(pageSize); Wm~` ~P
setTotalCount(totalCount); lH^^77"4Qo
setItems(items); %.v{N6
setStartIndex(startIndex); p^kUs0$GS
} 85:NFa@J
%sBAl.!BN
publicList getItems(){ &.13dq
return items; s'aip5P
} wFh8?Z3u_
[D"t~QMr
publicvoid setItems(List items){ Y}*\[}l:&x
this.items = items; 'nQVj
} o{b=9-V
EJ}!F?o
publicint getPageSize(){ N]EcEM #
return pageSize; 1LJuCI=~
} f*{
YFg?*&
sxKf&p;
publicvoid setPageSize(int pageSize){ :AdDLpk3j
this.pageSize = pageSize; -~[9U,
} /^{BUo
7\zZpPDV
publicint getTotalCount(){
JCcZuwu[
return totalCount; 9fnA
} #o/H~Iv
/M~!sPW&?
publicvoid setTotalCount(int totalCount){ ,21 np
if(totalCount > 0){ |s#'dS;
this.totalCount = totalCount; `i) 2nNJ"
int count = totalCount / `(+o=HsD
mffn//QS
pageSize; NgCuFL(Ic
if(totalCount % pageSize > 0) u?Tpi[
#
count++; @RFs/'
indexes = newint[count]; \I-#1M
for(int i = 0; i < count; i++){ uJHu>M}~
indexes = pageSize * v[@c*wo
87)zCq
i; .#u_#=g?
} )Au6Nf
}else{ iqQUtE]E_
this.totalCount = 0; GuZ( &G6*
} 4H5pr
} !MDNE*_
)D'^3)FF
publicint[] getIndexes(){ u<q :$
return indexes; 'bGX-C
} > oA?6x
&Cim!I
publicvoid setIndexes(int[] indexes){ QVF]Ci_=
this.indexes = indexes; "Td`AuP@,
} bPD`+:A_
8(.mt/MR
publicint getStartIndex(){ R+q"_90_
return startIndex; Xtz-\v#0o'
} KTvzOI8
pL1Q7&&c0
publicvoid setStartIndex(int startIndex){ 6iEhsL&K
if(totalCount <= 0) zf4Ec-)
this.startIndex = 0; fPi3sb`}
elseif(startIndex >= totalCount) qm Tb-~
this.startIndex = indexes '\~$dtI$
F/m^?{==~*
[indexes.length - 1]; -LDCBc"
elseif(startIndex < 0) *#%9Rp2|
this.startIndex = 0; +X`V|E,no
else{ I)q,kP@yY
this.startIndex = indexes _LAS~x7,
wiaX&-c]8
[startIndex / pageSize]; IM$2VlC
} <2!v(EkI
} >{eCh$L
nzjkX4KV
publicint getNextIndex(){ FJ*i\Q/D
int nextIndex = getStartIndex() + ]sz3]"2
Q%/<ZC.Mz6
pageSize; AM"Nn
L"
if(nextIndex >= totalCount) 4!asT;`'
return getStartIndex(); Q6o(']0
else O20M[_S
return nextIndex; i |{Dd%4vK
} |9"p|6G?B
7&`}~$>}>e
publicint getPreviousIndex(){ a9n^WOJ6
int previousIndex = getStartIndex() - qQpnLV 4
(>mI'!4d
pageSize; YY?a>j."a
if(previousIndex < 0) /&u<TJ4
return0; ze_{=Cv&Y
else Wv__ wZ
return previousIndex; Ngr/QL]Q
} VIP7OHJh
*Ype>x{
} @)kO=E d
DjU9
uZT
hlu:=<B
,+qVu,
抽象业务类 hjO*~
java代码: WwC 5!kZ
K =.%$A
w;Q;[:y
/** s[8@*/ds
* Created on 2005-7-12 2&+#Vsm`V
*/ J--m[X
package com.javaeye.common.business; T081G`li
J7C4V'_
import java.io.Serializable; yCJ Fo
import java.util.List; r ]W
Oz|K8p
import org.hibernate.Criteria; 79\JxiSB
import org.hibernate.HibernateException; zkTp`>9R
import org.hibernate.Session; |IunpZV
import org.hibernate.criterion.DetachedCriteria; Ngb(F84H?
import org.hibernate.criterion.Projections; awvDe
import h25G/`
:{NC-%4o0
org.springframework.orm.hibernate3.HibernateCallback; f84:hXo6
import i"|$(2
0y<wvLv2C
org.springframework.orm.hibernate3.support.HibernateDaoS Q'k\8'x
[4fU+D2\d
upport; p8s:g~ W
"<}&GcJbz
import com.javaeye.common.util.PaginationSupport; J 5h+s-'
+A~\tK{
public abstract class AbstractManager extends e4~>G?rM_
+(uYwdcN
HibernateDaoSupport { F}"] 92
LqdY Qd51
privateboolean cacheQueries = false; LZ@|9!KDw
&z"krM]G
privateString queryCacheRegion; b':|uu*/
}F+zs*S
publicvoid setCacheQueries(boolean Qu,8t8
9h/>QLx
cacheQueries){ P}.7Mehf
this.cacheQueries = cacheQueries; AxxJk"v'y
} m/N dJMoN=
3] 1-M
publicvoid setQueryCacheRegion(String OB~X/
"O8gJ0e
queryCacheRegion){ IVlf=k
this.queryCacheRegion = )
'j:
+UJuB
queryCacheRegion; _C\[DR0n
} zI~owK)%Z
47r_y\U h
publicvoid save(finalObject entity){ !_2n
getHibernateTemplate().save(entity); `OymAyEYQ
} ~}K5#<
8q`$y$06Dk
publicvoid persist(finalObject entity){ K78rg/`
getHibernateTemplate().save(entity); 8 6f2'o+
} CF|]e:
*&Z7m^`FQ
publicvoid update(finalObject entity){ WvHw{^(lF
getHibernateTemplate().update(entity); L6>pGx
} ,G#.BLH
cX
g'];Estb~
publicvoid delete(finalObject entity){ 1 nvTce
getHibernateTemplate().delete(entity); '8Phxx|
} |*RYq2y
@\&m+;6
publicObject load(finalClass entity, Th`skK&U
S osj$9E
finalSerializable id){ LQnkcV
return getHibernateTemplate().load 10#oG{9
+.y
.Mp
(entity, id); \D>$aLO*?
} iqnJ~g
T]Nu)
publicObject get(finalClass entity, %!ebO*8q
b|SE<\
finalSerializable id){ kj+#TnF-
return getHibernateTemplate().get VL[)[~^
gPC*b+
(entity, id); 'WHHc 9rG,
} 8@NH%zWBp
:Q+5,v-c
publicList findAll(finalClass entity){ I ];M7
return getHibernateTemplate().find("from kP xa7
#k3t3az2{
" + entity.getName()); 1Y_w5dU
} +h2eqNr
-/]W+[
publicList findByNamedQuery(finalString t>B^q3\q?
c`x7u}C
namedQuery){ ?j^=u:<
return getHibernateTemplate ( 6(x'ByT
E1;@=#t2i
().findByNamedQuery(namedQuery); q_
=b<.;
}
"o& E2#
(wc03,K^
publicList findByNamedQuery(finalString query, +l^LlqA
{b]aC
finalObject parameter){ */ G<!W
return getHibernateTemplate |}){}or
UN"(5a8.
().findByNamedQuery(query, parameter); s<x1>Q7X~
} /S:F)MO9
yBLK$@9
publicList findByNamedQuery(finalString query, p2PY@d}}.
cNzt%MjP
finalObject[] parameters){ tU"raP^=
return getHibernateTemplate 4[ryKPa,
{%w!@-
().findByNamedQuery(query, parameters); o`khz{SU:
} hVjNZ
y80ykGPT\&
publicList find(finalString query){ _w@qr\4i=
return getHibernateTemplate().find UEak^Mm;=2
\yrisp#`
(query); :hGPTf
} _wb0'xoK"
93[DAs
publicList find(finalString query, finalObject k
{-
k\Q,h75
parameter){ d@mo!zu
return getHibernateTemplate().find HxK$ 4I`
8\<jyJ
(query, parameter); p}Fs'l?7Rq
} wix5B@
VC5_v62&.
public PaginationSupport findPageByCriteria %tA57Pn>
F>]#}_
(final DetachedCriteria detachedCriteria){ eMK+X \
return findPageByCriteria TG
n-7 88
VcK}2<8:+~
(detachedCriteria, PaginationSupport.PAGESIZE, 0); v+6@cC
} N__H*yP
(3\Xy
public PaginationSupport findPageByCriteria r!}al5~&
Dc~,D1xWj
(final DetachedCriteria detachedCriteria, finalint 66snC{gU
%/kyT%1
startIndex){ G;gJNK"e
return findPageByCriteria 4
;Qlu
T~sTBGcv
(detachedCriteria, PaginationSupport.PAGESIZE, ]j>i.5
OEdJc\n_R
startIndex); mq /zTm
} "S~_[/q
(_*
wt]"'
public PaginationSupport findPageByCriteria FDR1Gy
]43[6Im
(final DetachedCriteria detachedCriteria, finalint dsK&U\ej}
F?Ju??O
pageSize, \^*<
y-jL
finalint startIndex){ Y^$HrI(vq
return(PaginationSupport) 'NZGQebK
%Qn(rA@9
getHibernateTemplate().execute(new HibernateCallback(){ "a1O01n
publicObject doInHibernate Np)3+!^1"
&R+#W
(Session session)throws HibernateException { jdevat,&u
Criteria criteria = us?&:L|!=
ba@ax3
detachedCriteria.getExecutableCriteria(session); %IL6ix
int totalCount = OLq
0V3m
B68H&h]D#'
((Integer) criteria.setProjection(Projections.rowCount 4{9d#[KW
x@P{l&:>
()).uniqueResult()).intValue(); 6FfOH<\z6i
criteria.setProjection } :iBx
b|^I<7
(null); wh 0<Uv
List items = v4?iOD
^CzYDq
criteria.setFirstResult(startIndex).setMaxResults ]kktoP|D
B%<e FFV\
(pageSize).list(); %Xh fXd'
PaginationSupport ps = Ft%hh|$5y
HN5W@5m:
.
new PaginationSupport(items, totalCount, pageSize, lp&!lb`
jyW[m,#(go
startIndex);
1S%k
return ps; "u}9@}*
} @^nu#R
}, true); jRkC/Lw
} bv?0.{Z
@b!"joEy
public List findAllByCriteria(final A3P9.mur
k/Mp6<?C:
DetachedCriteria detachedCriteria){ ~M?|Vn
return(List) getHibernateTemplate O^{1RV3:,T
t7#lsd`_
().execute(new HibernateCallback(){ .I?@o8'x
publicObject doInHibernate #/J
'P[z
upn8n vy4(
(Session session)throws HibernateException { 8?TKN~ja
Criteria criteria = lpQP"%q
TZ^LA
L'8_
detachedCriteria.getExecutableCriteria(session); aP~gaSx
return criteria.list(); <2Y0{
8)
} 6=|&tE
}, true); 6DS43AQs
} 2iXoj&3e
v<rF'D2
public int getCountByCriteria(final L0Vgo<A
+Al>2 ~
DetachedCriteria detachedCriteria){ u'9gVU B
Integer count = (Integer) o sdOw8
tR`S#rk
getHibernateTemplate().execute(new HibernateCallback(){ = (U/CI
publicObject doInHibernate K\=8eg93Z
-R+zeu(e'
(Session session)throws HibernateException { Q49BU@xX
Criteria criteria = }*;EFR 6'
(*^DN{5
detachedCriteria.getExecutableCriteria(session); +!>LY
return u?Hb(xZtg=
MB$a82bY
criteria.setProjection(Projections.rowCount a#(U2OP
vgPUIxB@
()).uniqueResult(); D(Ix!G/
} !c8L[/L
}, true); #;j9}N
return count.intValue(); T`L}[?w
} vb =CFV#
} VZxTx0: ,
4KIWb~0Y
Cyk s
'Tf9z+0;
_'iDF
FUTn
用户在web层构造查询条件detachedCriteria,和可选的 f'/ KMe%<
2ChWe}f
startIndex,调用业务bean的相应findByCriteria方法,返回一个 /5a;_
tjzA)/T,4
PaginationSupport的实例ps。 }OKL
z.5
XCPb9<L
ps.getItems()得到已分页好的结果集 ]mkJw 3
ps.getIndexes()得到分页索引的数组 `"<2)yq?
ps.getTotalCount()得到总结果数 p]f&mBO*
ps.getStartIndex()当前分页索引 MQ w9X
ps.getNextIndex()下一页索引 u^Sv#K X
ps.getPreviousIndex()上一页索引 }""p)Y&
XeUprN
8fO8Dob]\Y
XL"=vbD
v&0d$@6/U
>q|Q-I~gs
PZ]5Hf1"
连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 i.@*tIK
_EKF-&Q6
,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 <c%n?QK{
;~ee[W$1
一下代码重构了。 /Dd\PjIH{
pcpxe&S
我把原本我的做法也提供出来供大家讨论吧: ya>N.h
b.Su@ay@(^
首先,为了实现分页查询,我封装了一个Page类: [}k|
java代码: ./iXyta
]Y5dl;xrM)
rgR?wXW]jE
/*Created on 2005-4-14*/ elKx]%k*)
package org.flyware.util.page; y9
uVCR
i7v/A&Rc
/** ~= 9Vv
* @author Joa *PcVSEP/0
* @,6ST0xT (
*/ &wGg6$
publicclass Page { rt;gC[3\
vl~%o@*_
/** imply if the page has previous page */ HWbBChDF
privateboolean hasPrePage; GMb!Q0I8
W:B }u\)C
/** imply if the page has next page */ =
o+7xom
privateboolean hasNextPage; @^HwrwRA
RK3.-
/** the number of every page */ fk\5D[j^
privateint everyPage; 6aSM*S)
_h~p:=
/** the total page number */ c%yh(g
privateint totalPage; fv|%Ocm
1}DerX 6
/** the number of current page */ :|($,3*
privateint currentPage; It\BbG=
-d_ 7*>m$
/** the begin index of the records by the current &Q+]t"OA!
w%~qB5wF6
query */ Zjt9vS)
privateint beginIndex; ;qG1r@o
V<W02\Hs
[J:zE&aj
/** The default constructor */ ahoh9iJ
public Page(){ C zpsqTQ
'Aet{A=9
} ,*w>z
Jmy)J!ib*
/** construct the page by everyPage g1dmkX
* @param everyPage :+1bg&wQ
* */ JOgmF_(>Z
public Page(int everyPage){ f-s~Q4
this.everyPage = everyPage; kI]=&Rw
} {"}+V`O{
7(5]Ry:
/** The whole constructor */ yHtGp%j
public Page(boolean hasPrePage, boolean hasNextPage, 8tC + lc
(V^QQ !:
[BE:+ ID3
int everyPage, int totalPage, )_F(H)*
int currentPage, int beginIndex){ % IPyCEJD
this.hasPrePage = hasPrePage; 3li q9P_
this.hasNextPage = hasNextPage; a(g$ d2H
this.everyPage = everyPage; |'@V<^ GR
this.totalPage = totalPage; K.r!?cfv
this.currentPage = currentPage; mR6E]TuM
this.beginIndex = beginIndex; P69>gBZYD
} s|KfC>#
D~7%};D[
/** y#nSk%"t"
* @return w0\4Wa
* Returns the beginIndex. L&rO6
*/ -
Ra\^uz
publicint getBeginIndex(){ 'bG1U`v=3
return beginIndex; (T4k~T`3
} U0zW9jB
UzN8G$92qF
/** B\NcCp`5
* @param beginIndex @!,D%]8"
* The beginIndex to set. -^y1iN'D
*/ XZ;*>(
publicvoid setBeginIndex(int beginIndex){ :Z]/Q/$
this.beginIndex = beginIndex; 8[f8k3g
} @ >
cdHv
H2s*s[T
-
/** Kl!DKeF
* @return w# xncH:1
* Returns the currentPage. X #H:&*[!
*/ c-v*4b/d
publicint getCurrentPage(){ %oMWcgsdJi
return currentPage; 4h(jw
} zmdWVFVv
:R{x]sv
/** u;QH8LK
* @param currentPage 4$qNcMdz
* The currentPage to set. [Aa[&RX+9
*/ +q$xw}+PK
publicvoid setCurrentPage(int currentPage){ _Eszr(zJ
this.currentPage = currentPage; Cd$dnHVh
} P~n8EO1r
CuF%[9[cT
/** ,,zd.9n
* @return z^YeMe
* Returns the everyPage. _95- -\
*/ ;sm"\.jF
publicint getEveryPage(){ !XkymIX~O.
return everyPage; !4i,%Z&6
} b*@&c9I;q
0@JilGk1u
/** q+r `e
* @param everyPage ~r{\WZ.
* The everyPage to set. J~M H_N
*/ |;X?">7NW
publicvoid setEveryPage(int everyPage){ N:"M&EUM
this.everyPage = everyPage; 7AS.)Q#=x
} "m
wl-=
>SY2LmV'a
/** hw EZj`9
* @return (R9QBZP5
* Returns the hasNextPage. m+;B!46
*/ (rau8
publicboolean getHasNextPage(){ &Bj,.dD/a
return hasNextPage; TXZ(mj?
} 49iR8w?k
hP ,b-R9\
/** jsK|D{m?
* @param hasNextPage 4Z<]4:o
* The hasNextPage to set. Kx(76_XD
*/ tn(?nQN3
publicvoid setHasNextPage(boolean hasNextPage){ D|u^8\'.
this.hasNextPage = hasNextPage; '-$))AdD
} wUh3Hd'
-lJx%9>
/** y|&.v<
* @return !V$6+?2
* Returns the hasPrePage. >!:$@!6L
*/ #i}# jMT
publicboolean getHasPrePage(){ /k4^&
return hasPrePage;
'7S!6kd?
} 34/]m/2NZK
lBizC5t!o
/** (= S"Kvb~#
* @param hasPrePage ^KaqvG$ed
* The hasPrePage to set. z v L>(R
*/ 1 2%z3/i
publicvoid setHasPrePage(boolean hasPrePage){ h(+m<J
this.hasPrePage = hasPrePage; 4GMa5]Ft
} 0A#9C09
tdMP,0u
/** ,yB?~
* @return Returns the totalPage. "ZA$"^
* 4?P%M"\Iv
*/ Fi?U)T+%+
publicint getTotalPage(){ lp37irI:
return totalPage; JLFFh!J
} j`[yoAH
kR`6s
/** D:ql^{~
* @param totalPage -dc"N|.
* The totalPage to set. lOWB^uS%
*/ 9^#zxmH)
publicvoid setTotalPage(int totalPage){ KZp,=[t
this.totalPage = totalPage; XwKZv0ub
} kuKnJWv
5WtQwN~
} (R;)
9I\
}5TfQV6
1)P<cNj
CYTuj>Ww
!:g>CDA
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 Y:tW]
s/W!6JX4
个PageUtil,负责对Page对象进行构造: YYZs#_
java代码: EyKkjEXx_
*<|~=*Ddf
^cKv JSY
/*Created on 2005-4-14*/ rC1qGzg\a
package org.flyware.util.page; +[X.-,yW
,N))=/
import org.apache.commons.logging.Log; 6\)8mK
import org.apache.commons.logging.LogFactory; o1p$9PL\:
TNX%_Q<
/** VrnK)za*H
* @author Joa )$9C` d[
* ecSdU>
*/ .Y^d9.
publicclass PageUtil { .NNcc4+
k
vue@
privatestaticfinal Log logger = LogFactory.getLog }e/[$!35
vJ'yz#tl9
(PageUtil.class); 4cErk)F4
_Gs
/** c*M)DO`y;h
* Use the origin page to create a new page s$DT.cvO
* @param page K8yyxJ
* @param totalRecords w>9H"Q[
* @return Hd=D#u=A4{
*/ @2%VU#!m
publicstatic Page createPage(Page page, int :Z*02JwK
Lv, ji_
totalRecords){ H(5ui`' s
return createPage(page.getEveryPage(), ~q#[5l(r8
w ufKb.4`
page.getCurrentPage(), totalRecords); i$fjr[$B
} *'`3]!A
lo>-}xd
/** 9m#H24{V'
* the basic page utils not including exception 9+N._u
&ESR1$)'P
handler @LkW_
* @param everyPage ![X.%
* @param currentPage *+,Lc1|\
* @param totalRecords SCI-jf3WN
* @return page 56O<CgJF<
*/ )z4kP09
publicstatic Page createPage(int everyPage, int !5'
8a5
I")"s
currentPage, int totalRecords){ @$b+~X)7
everyPage = getEveryPage(everyPage); um_M}t{
currentPage = getCurrentPage(currentPage); !w;A=
int beginIndex = getBeginIndex(everyPage, v#<+n{B
./BP+\)lO
currentPage); v%l|S{>(
int totalPage = getTotalPage(everyPage, *`pec3"
[ ;3EzZL
totalRecords); z*k3q`=>
boolean hasNextPage = hasNextPage(currentPage, Ie`SWg*WL
Y(G*Yi?;
totalPage); O7<V@GL+
boolean hasPrePage = hasPrePage(currentPage); CSk
> {LJ#Dc6
returnnew Page(hasPrePage, hasNextPage, m|?"
k38
everyPage, totalPage, 5@%=LPV
currentPage, 4~pO>6P
/kviO@jm4(
beginIndex); $Zu4tuXA
} 7PQj7&m
g)r,q&*
privatestaticint getEveryPage(int everyPage){ )/N Xh'
return everyPage == 0 ? 10 : everyPage; onJ[&f
} M'!!EQo
hcp'+:
privatestaticint getCurrentPage(int currentPage){ sVm'9k
return currentPage == 0 ? 1 : currentPage; u):Rw
} 1rm$@L
omUl2C
privatestaticint getBeginIndex(int everyPage, int -WHwz m
\<MTY:
currentPage){ a\.O L}"
return(currentPage - 1) * everyPage; 8`LLHX1|
} !f]3Riw-=,
J\,e/{,X
privatestaticint getTotalPage(int everyPage, int m%$E[cUW!
.n|3A3:
totalRecords){ WG[0$j
int totalPage = 0; C>K"ZJ
$Ln2O#
if(totalRecords % everyPage == 0) j"$b%|
totalPage = totalRecords / everyPage; ?[>BssW
else :#!F 7u
totalPage = totalRecords / everyPage + 1 ; $gD(MKR)~
;Wrd=)Ka
return totalPage; s)&R W#:X
} =ILo`Q~
xzf)_ <
privatestaticboolean hasPrePage(int currentPage){ ]I*#R9
return currentPage == 1 ? false : true; |sZ9/G7
} q&Ua(I
J`D<
privatestaticboolean hasNextPage(int currentPage, V:"\(Y
va*>q-QCr
int totalPage){ ea[a)Z7#
return currentPage == totalPage || totalPage == xyJgHbml
<wGTs6
0 ? false : true; #(Yb
lY
} qP .VK?jF|
);.<Yf{c
qaSv]k.
} s].Cx4VQ
0#[Nfe*
[.#$hOsNR
;7og
b8-^wJH!
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。 1nM?>j%k
j~j
V`>A
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 ne~#{q
By"ul:.D
做法如下: H(ftOd.y
1. 编写一个通用的结果存储类Result,这个类包含一个Page对象 %KVRiX
5>k~yaju/
的信息,和一个结果集List: <HX-qNA?
java代码: [(^''*7r+T
$/(/v?3][e
E6IL,Iq9
/*Created on 2005-6-13*/ WAXrA$:3J
package com.adt.bo; 21J82M
!m.')\4<
import java.util.List; 2!& ;ZcT,
K0!#l Br
import org.flyware.util.page.Page; C&K(({5O
E]Gq!fA&<
/** JU`'?b
* @author Joa XXdMp poR
*/ 9*Mg<P"
publicclass Result { eMMiSO!3
VQJ5$4a&
private Page page; mp$II?hZ*
Rn^N+3o'M
private List content; MhB=+S[@
?=o]Wx0(9
/** ;."{0gq
* The default constructor ,3TD $2};.
*/ '`VO@a
public Result(){ HDG"a&$
super(); j{+I~|ZB,
} H;}ue
C2%3+
/** *m Tc4&*
* The constructor using fields R}mWHB_h"
* .TU15AAc
* @param page @?NLME
* @param content NNV.x7
*/ 24k}~"We
public Result(Page page, List content){ $f-pLF+x
this.page = page; N9hWx()v
this.content = content; sSb&r
} g}`CdVQ2M<
R1%T>2"~&
/** 2MrR|hLx
* @return Returns the content. "tbBbEj?d
*/ \DdVMn
publicList getContent(){ ?4dd|n
return content; &%51jM<
} ^Q:`2C5
G`K7P`m
/** KUV{]?'
* @return Returns the page. dKG<"
*/ j>=".^J
public Page getPage(){ (.t:sn"P
return page; }{PtQc6RL!
} ~oyPmIcb
W|
eG}`
/** m#(x D~V
* @param content D#(L@{vC
* The content to set. K_Gf\x
*/ @y%qQe/g
public void setContent(List content){ Gs?sO?j
this.content = content; uB9+E%jOdQ
} G!Q)?N
{i?K~|
h
/** a .Vs>1
* @param page ITOGD
* The page to set. P=i |{vv(
*/ l )eaIOyk
publicvoid setPage(Page page){ 2Nszxvq,
this.page = page; )7TTRL
} r+obm)Qtp
} v<4X;4p^
jtJU5Q
O~1p]j
FiH!)6T
S!c@6&XJm?
2. 编写业务逻辑接口,并实现它(UserManager, @uWD>(D
U;Wmx
UserManagerImpl) Kn]WXc|("
java代码: hj[g2S%X
}e6:&`a xD
3@A k6Uh
/*Created on 2005-7-15*/ T{Q&